HRT

Distribution by Scientific Domains
Distribution within Medical Sciences

Terms modified by HRT

  • hrt parameter
  • hrt use
  • hrt user

  • Selected Abstracts


    Flow cytometry versus histamine release analysis of in vitro basophil degranulation in allergy to Hymenoptera venom

    CYTOMETRY, Issue 1 2003
    C. Lambert
    Abstract Background Flow cytometry (FCM) has been proposed for specific allergy in vitro testing. We investigated its biological significance for allergy to Hymenoptera venoms and compared it with the routinely performed basophil histamine release test (HRT). Methods Blood samples from 26 allergic and 8 nonallergic donors were incubated with venom at serial concentrations. Basophils were analyzed with anti-CD45-PE-Cyanin 5, Anti-IgE-FITC, and Anti-CD63-Phycoerythrine. HRT was measured by radioimmunoassay. Results FCM was as convenient as HRT for measuring basophil reactivity in at least 87% of allergic and 75% of nonallergic subjects. CD63 outer expression was specifically induced in 91% of releaser subjects (86% on HRT) and in 1 of 10 tests in nonallergic donors, or one of six tests (16% on HRT) in allergic patients tested with an irrelevant allergen. Both methods were concordant in 85.7% of the tests. The three discordant patients had low-grade reactions and borderline biological responses on FCM (n = 2) or HRT (n = 1). Conclusions The dynamic, physiologic significance of CD63, the dose,response curve, and dependency on ethylene-diaminetetra acetic acid suggested that both tests reflect the same mechanism. Cytometry Part B (Clin. Cytometry) 52B:13,19, 2003. © 2003 Wiley-Liss, Inc. [source]


    The benefits of oestrogens on postprandial lipid metabolism are lost in post-menopausal women with Type 2 diabetes

    DIABETIC MEDICINE, Issue 7 2006
    M. G. Masding
    Abstract Aims, Women with Type 2 diabetes appear to lose the protection against cardiovascular disease (CVD) afforded by oestrogens. We examined the effects of oestrogen hormone replacement therapy (HRT) on postprandial clearance of dietary fat in non-diabetic and diabetic post-menopausal women. Methods, In a cross-sectional study, fasting subjects [HRT+ and HRT, control and diabetic women; Type 2 diabetes (DM) HRT+n = 8, DM HRT,n = 14, control HRT+n = 7, control HRT,n = 11] consumed a meal containing the stable isotope 1,1,1,[13]C-tripalmitin, with blood and breath sampled for 6 and 24 h, respectively, in the postprandial period. Results, In diabetic women, there were no differences between the HRT+ and HRT, groups for any of these parameters. In contrast, in HRT+ compared with HRT, control women, the triglyceride (TG) area under the curve was lower [AUC; HRT+ median (range) 7.7 (4.1, 12.8) mmol/l per 6 h, HRT, 9.7 (3.9, 18.5) mmol/l per 6 h, P < 0.05] and [13]C-palmitic acid in the TG fraction was also lower [HRT+ 23.2 (10.3, 41.3) ng/ml per 6 h, HRT, 47.7 (12.6, 77.2) ng/ml per 6 h, P < 0.05], suggesting the lower postprandial triglyceridaemia associated with HRT in non-diabetic women is because of better chylomicron clearance. Conclusions, The oestrogen-associated advantage in clearance of dietary lipid we observed in non-diabetic post-menopausal women is not seen in post-menopausal diabetic women. This is likely to promote an atherogenic lipoprotein profile and may contribute to the loss of CVD protection seen in diabetic women. [source]


    Cytohormonal and morphological alterations in cervicovaginal smears of postmenopausal women on hormone replacement therapy

    DIAGNOSTIC CYTOPATHOLOGY, Issue 10 2006
    Sanjay Gupta M.D.
    Abstract The objective of the study was to study the cytohormonal and morphological alterations in cervicovaginal smears associated with the use of hormone replacement therapy (HRT) and to assess the utility of vaginal cytology in determining the response to HRT. Ninety postmenopausal women (30 on estrogen,progesterone combination (HRT) for 1 to 24 mo (user 1), 30 on estrogen therapy (ERT) for 1 to 44 mo (user 2), and 30 not on any hormones (nonusers)) were included in the cross-sectional study. Their lateral vaginal wall smears and cervical smears were examined for hormonal and morphological assessments, respectively. The smear pattern showed predominance of parabasal cells in 46.6% of nonusers, while none of the users had >70% parabasal cells. A high percentage (>70%) of intermediate cells was found in 46.6% of users and only in 16.6% of nonusers. A high maturation value (MV) was found in more than 75% of users but in only 16.6% of nonusers. The women with high MV (>50) were significantly less symptomatic than did nonusers. Atrophic changes were present in cervical smears of 14/20 (46.6%) nonusers when compared with 1/60 (1.66%) users. Atypical squamous cells of undetermined significance (ASC-US) were diagnosed in seven users and three nonusers. It persisted on follow-up in four users and one nonuser. Histology revealed one mild dysplasia among users. Lactobacilli were more frequently observed in users. The cytohormonal pattern on vaginal smears correlates well with the response to hormonal therapy and clinical symptoms. Awareness of the morphological alterations associated with the use of replacement hormones would enable the cytologists to reduce the false-positive diagnoses while evaluating postmenopausal smears. Diagn. Cytopathol. 2006;34:676,681. © 2006 Wiley-Liss, Inc. [source]


    Microbial Community Dynamics of a Continuous Mesophilic Anaerobic Biogas Digester Fed with Sugar Beet Silage

    ENGINEERING IN LIFE SCIENCES (ELECTRONIC), Issue 4 2008
    B. Demirel
    Abstract The aim of the study was to investigate the long-term fermentation of an extremely sour substrate without any addition of manure. In the future, the limitation of manure and therefore the anaerobic digestion of silage with a very low buffering capacity will be an increasing general bottleneck for energy production from renewable biomass. During the mesophilic anaerobic digestion of sugar beet silage (without top and leaves) as the sole substrate (without any addition of manure), which had an extreme low pH of around 3.3, the highest specific gas production rate (spec. GPR) of 0.72,L/g volatile solids (VS),d was achieved at a hydraulic retention time (HRT) of 25,days compared to an organic loading rate (OLR) of 3.97,g VS/L,d at a pH of around 6.80. The methane (CH4) content of the digester ranged between 58 and 67,%, with an average of 63,%. The use of a new charge of substrate (a new harvest of the same substrate) with higher phosphate content improved the performance of the biogas digester significantly. The change of the substrate charge also seemed to affect the methanogenic population dynamics positively, thus improving the reactor performance. Using a new substrate charge, a further decrease in the HRT from 25 to 15,days did not influence the digester performance and did not seem to affect the structure of the methanogenic population significantly. However, a decrease in the HRT affected the size of the methanogenic population adversely. The lower spec. GPR of 0.54,L/g,VS,d attained on day,15 of the HRT could be attributed to a lower size of methanogenic population present in the anaerobic digester during this stage of the process. Furthermore, since sugar beet silage is a relatively poor substrate, in terms of the buffering capacity and the availability of nutrients, an external supply of buffering agents and nutrients is a prerequisite for a safe and stable digester operation. [source]


    Acclimation Strategy of a Biohydrogen Producing Population in a Continuous-Flow Reactor with Carbohydrate Fermentation

    ENGINEERING IN LIFE SCIENCES (ELECTRONIC), Issue 4 2006
    Q. Ren
    Abstract Poor startup of biological hydrogen production systems can cause an ineffective hydrogen production rate and poor biomass growth at a high hydraulic retention time (HRT), or cause a prolonged period of acclimation. In this paper a new startup strategy was developed in order to improve the enrichment of the hydrogen-producing population and the efficiency of hydrogen production. A continuously-stirred tank reactor (CSTR) and molasses were used to evaluate the hydrogen productivity of the sewage sludge microflora at a temperature of 35,°C. The experimental results indicated that the feed to microorganism ratio (F/M ratio) was a key parameter for the enrichment of hydrogen producing sludge in a continuous-flow reactor. When the initial biomass was inoculated with 6.24,g of volatile suspended solids (VSS)/L, an HRT of 6,h, an initial organic loading rate (OLR) of 7.0,kg chemical oxygen demand (COD)/(m3,×,d) and an feed to microorganism ratio (F/M) ratio of about 2,3,g COD/(g of volatile suspended solids (VSS) per day) were maintained during startup. Under these conditions, a hydrogen producing population at an equilibrium state could be established within 30,days. The main liquid fermentation products were acetate and ethanol. Biogas was composed of H2 and CO2. The hydrogen content in the biogas amounted to 47.5,%. The average hydrogen yield was 2.01,mol/mol hexose consumed. It was also observed that a special hydrogen producing population was formed when this startup strategy was used. It is supposed that the population may have had some special metabolic pathways to produce hydrogen along with ethanol as the main fermentation products. [source]


    Long-term stability of biological denitrification process for high strength nitrate removal from wastewater of uranium industry

    ENVIRONMENTAL PROGRESS & SUSTAINABLE ENERGY, Issue 3 2008
    Prashant M. Biradar
    Abstract The aim of the present study was to biologically denitrify uranium nitrate raffinate (UNR) from nuclear industry, which is a principle source of high strength nitrate waste. To denitrify the high nitrate waste, a pilot-scale continuous stirred tank reactor was designed with two inbuilt settlers. Acclimatization of mixed culture with synthetic waste was carried out prior to the inoculation of the acclimatized sludge into the reactor. Initial concentration of nitrate in uranium raffinate was 77,000 mg/L NO3. It was diluted and used as a feed to the reactor. Concentration of nitrate in feed was increased gradually from 10,000 mg/L NO3 to 40,000 mg/L NO3 with hydraulic retention time (HRT) maintained at 34.4 h. Complete denitrification of 40,000 mg/L NO3 was achieved in a specified HRT. To facilitate understanding of the treatablity and long-term stability of biological denitrification of UNR, study was carried out for 211 days by periodical perturbation of the system. Furthermore, to find the volume ratio of reactor to settler required for the full-scale design of the denitrification plant, settling of acclimatized sludge was carried out. © 2008 American Institute of Chemical Engineers Environ Prog, 2008 [source]


    Hormone replacement therapy and headache prevalence in postmenopausal women.

    EUROPEAN JOURNAL OF NEUROLOGY, Issue 1 2007
    The Head-HUNT study
    Conflicting evidence exists whether hormone replacement therapy (HRT) is a risk factor for headache. The aim of the study was to examine the prevalence of headache and migraine amongst postmenopausal women using HRT. In the Nord-Trøndelag Health Study 1995,97 (HUNT 2), 18 323 (62%) out of 29 679 women aged 40 years or more responded to headache questions (Head-HUNT). Amongst the 6007 postmenopausal women, 5507 (92%) responded to questions regarding use of HRT (2375 used or had used it) and questions related to headache (2407 had complaints). There was a significant association between headache and present use of HRT, both with local [odds ratio (OR) = 1.4, 95% confidence intervals (CI) 1.1,1.7] and systemic (OR = 1.6, 95% CI 1.4,1.9) application. This was found for non-migrainous headache (OR = 1.3, 95% CI 1.1,1.5) and migraine (OR = 1.6, 95% CI 1.4,1.9). Both migraine and non-migrainous headache were more probably amongst users of postmenopausal HRT than amongst those who had never used HRT. Whether HRT caused headache or was used partly because of headache cannot be determined in this cross-sectional study. [source]


    Tapovan-Vishnugad hydroelectric power project , experience with TBM excavation under high rock cover / . Tapovan-Vishnugad Wasserkraftwerk , Erfahrungen mit TBM-Vortrieb bei hoher Überlagerung

    GEOMECHANICS AND TUNNELLING, Issue 5 2010
    Johann Brandl
    Mechanised tunnelling - Maschineller Vortrieb; Hydro power plants - Wasserkraftanlagen Abstract NTPC Ltd. of India is presently constructing the 520 MW (4 x 30 MW) Tapovan-Vishnugad hydroelectric power plant in Uttarakhand in the Himalayas. As part of this project, an approximately 12.1 km head race tunnel (HRT) is to be constructed, of which approximately 8.6 km are being excavated by DS-TBM with an excavation diameter of 6.575 m. Construction of this HRT has been awarded to a Joint Venture (JV) of Larsen, Toubro Ltd., India, and Alpine, Austria. Geoconsult ZT GmbH is acting as a Consultant to NTPC Ltd. for the TBM part of the HRT. The overburden above the tunnel is up to 1, 100 m with the result that knowledge of the geology along the HRT alignment could only be based on projections made from surface exposures available in the area. Basically, the ground consists of jointed quartzite, gneiss and schist. Excavation of the HRT started in October 2008 and excavation rates of over 500 m per month were achieved in November 2009. However, in December 2009 the TBM encountered a fault zone along with high-pressure water inflow and became trapped. This paper outlines the present status of HRT construction and describes in particular the difficulties encountered during TBM excavation in fault zones with large high-pressure water inflows and how these problems are being dealt with. Die indische Firma NTPC Ltd. errichtet derzeit das 520 MW (4 x 130 MW) Tapovan-Vishnugad Wasserkraftwerk in Uttarakhand, Himalaya. Als Teil dieses Projekts wird ein ungefähr 12,1 km langer Triebwasserstollen (TWS) errichtet, wobei rund 8,6 km davon mittels einer DS-TBM mit einem Ausbruchdurchmesser von 6.575 m aufgefahren werden. Der Bau dieses Triebwasserstollens wurde an die Arbeitsgemeinschaft Larsen, Toubro Ltd., Indien, und Alpine, Österreich vergeben. Geoconsult ZT GmbH fungiert als Berater von NTPC Ltd. für den TBM-Teil des TWS. Aufgrund der Überlagerung des Tunnels von bis zu 1,100 m konnte die Geologie entlang des Triebwasserstollens nur durch Projektion von vorhandenen Oberflächenaufschlüssen aus der Umgebung bestimmt werden. Das Gebirge besteht hauptsächlich aus geklüftetem Quarzit, Gneis und Schiefer. Der Ausbruch des TWS begann im Oktober 2008. Im November 2009 wurde eine Vortriebsgeschwindigkeit von über 500 m pro Monat erreicht. Im Dezember 2009 jedoch fuhr die TBM eine Störzone mit einem Hochdruckwassereinbruch an, wodurch die TBM stecken blieb. Dieser Artikel skizziert den derzeitigen Stand des TWS und legt besonderes Augenmerk auf die Schwierigkeiten beim Auffahren der Störzone inklusive Hochdruckwassereinbruch mit einer TBM. Darüber hinaus wird gezeigt, wie sich die auftretenden Probleme lösen lassen. [source]


    HRT and breast cancer

    HEALTH EXPECTATIONS, Issue 3 2004
    Heather Goodare
    No abstract is available for this article. [source]


    Patient and clinician collaboration in the design of a national randomized breast cancer trial

    HEALTH EXPECTATIONS, Issue 1 2004
    Jo Marsden MD FRCS (Gen Surgery)
    Abstract Objective, To show breast cancer patient involvement in the design of a national randomized trial of hormone replacement therapy (HRT) in symptomatic patients will increase accrual. Setting and participants, Three stakeholder groups [(1) researchers from the Lynda Jackson Macmillan Centre, (2) the Consumers' Advisory Group for Clinical Trials (CAG-CT), (3) clinicians responsible for a pilot randomized HRT study in breast cancer patients] developed this collaborative study. Methods, (1) Nine focus group discussions were conducted to identify issues relevant to breast cancer patients about HRT and a national trial: six involved women from breast cancer support groups nationwide and three patients who had previously participated in the pilot randomized HRT study. (2) Recommendations from the focus groups (analysed by Grounded Theory) were debated by the research stakeholders and focus group representatives at a 1-day meeting and consensus reached (using a voting system) on mutual priorities for incorporation into the design of a national HRT trial. (3) Representatives from the CAG-CT and focus groups participated in subsequent national HRT steering committee meetings to ensure that these priorities were accounted for and the resulting trial design summary was circulated to the CAG-CT and all focus group representatives for comment. Results, Focus groups demonstrated that the complexity of factors relating to trial participation was not just restricted to the research topic in question. Patient,clinician interaction provided a platform for negotiating potential conflicts over trial design and outcomes. Patient feedback suggested that mutually agreed priorities were accounted for in the trial design. Interpretation, Clinical research planning should involve all research stakeholders at the outset. Quantifying the impact of patient involvement in terms of trial accrual may be too simple given the complexity of their motivations for participating in trials. [source]


    The effect of riparian land use on transport hydraulics in agricultural headwater streams located in northeast Ohio, USA

    HYDROLOGICAL PROCESSES, Issue 1 2010
    Kyle S. Herrman
    Abstract This study examined if riparian land use (forested vs agricultural) affects hydraulic transport in headwater streams located in an agriculturally fragmented watershed. We identified paired 50-m reaches (one reach in agricultural land use and the other in forested land use) along three headwater streams in the Upper Sugar Creek Watershed in northeast Ohio, USA (40° 51,42,N, 81° 50,29,W). Using breakthrough curves obtained by Rhodamine WT slug injections and the one-dimensional transport with inflow and storage model (OTIS), hydraulic transport parameters were obtained for each reach on six different occasions (n = 36). Relative transient storage (AS:A) was similar between both reach types (As: A = 0·3 ± 0·1 for both agricultural and forested reaches). Comparing values of Fmed200 to those in the literature indicates that the effect of transient storage was moderately high in the study streams in the Upper Sugar Creek Watershed. Examining travel times revealed that overall residence time (HRT) and residence time in transient storage (TSTO) were both longer in forested reaches (forested HRT = 19·1 ± 11·5 min and TSTO = 4·0 ± 3·8 min; agricultural HRT = 9·3 ± 5·3 min and TSTO = 1·7 ± 1·4 min). We concluded that the effect of transient storage on solute transport was similar between the forested and agricultural reaches but the forested reaches had a greater potential to retain solutes as a result of longer travel times. Copyright © 2009 John Wiley & Sons, Ltd. [source]


    HMG-CoA reductase expression in breast cancer is associated with a less aggressive phenotype and influenced by anthropometric factors

    INTERNATIONAL JOURNAL OF CANCER, Issue 5 2008
    Signe Borgquist
    Abstract Although several studies have reported on the anti-tumoural properties exerted by 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMG-CoAR) inhibitors (statins), the in vivo expression of HMG-CoAR in human cancer has been considerably less investigated. In our study, we examined the immunohistochemical expression of HMG-CoAR in 511 incident breast cancers within the Malmö Diet and Cancer Study in order to explore its relationship to established clinicopathological and tumour biological parameters. Furthermore, the potential influence of estrogen exposure on HMG-CoAR expression was assessed by performing Cox's proportional hazards analyses of the relationship between the use of hormone replacement therapy (HRT), obesity (waist circumference) and tumour-cell specific HMG-CoAR expression. We found that HMG-CoAR was present in various fractions and intensities in the cytoplasm, sometimes with a membranous pattern, but not in the tumour cell nuclei. The expression of HMG-CoAR was associated with a smaller tumour size (p = 0.02), low histological grade (p = 0.001), low Ki67 index (p = 0.004), ER,+ (p = 0.02), ER,+ (p = 0.005), and high p27 expression (p = <0.001). The incidence of tumours with a high HMG-CoAR-expression was increased among HRT-users, although this was not statistically significant in a heterogeneity analysis. Obesity was significantly associated with a high HMG-CoAR expression assessed both as a high (>50%) fraction of positive cells (relative risk: 2.06; 95% confidence interval: 1.20,3.51), and a strong staining intensity (2.33: 1.08,5.02). In summary, we demonstrate that HMG-CoAR is differentially expressed in breast cancer and that a high expression is associated with prognostically favourable tumour parameters. Moreover, estrogen related life-style and anthropometric factors might indeed regulate HMG-CoAR expression. © 2008 Wiley-Liss, Inc. [source]


    Characteristics of skin aging in Korean men and women

    INTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 1 2005
    J. H. Chung
    Introduction Korea is located between Japan and Mainland China. The people of these three countries have similar appearances and it is difficult to differentiate between them. Although the population of Asia is more than half of the total population of the Earth, the inherent characteristics of Asian skin have not been well investigated. Commercial markets for cosmetics and drugs for photoaged skin are rapidly expanding in many Asian countries. Therefore, many investigators in the field of dermatology and cosmetology have become interested in brown Asian skin. Clinical characteristics of skin aging and photoaging in Asians Skin aging can be divided into two basic processes: intrinsic aging and photoaging [1]. Intrinsic aging is characterized by smooth, dry, pale, and finely wrinkled skin, whereas photoaging, which indicates premature skin aging in chronically photodamaged skin, is characterized by severe wrinkling and irregular pigmentation. The pattern of wrinkling in Asians seems to differ from that in Caucasians. Asians have coarser, thicker and deep wrinkles, particularly in the forehead, perioral and Crow's foot areas. In contrast, Caucasians usually have relatively fine cheek and Crow's foot wrinkles. The reasons for these differences are not known and need further investigation. There are racial, ethnic and genetic differences, and differences of skin structure and function, between the brown skin of Asians and the white skin of Caucasians. As Asian skin is more pigmented, acute and chronic cutaneous responses to UV irradiation differ from those in white skin. Many people believe, based on clinical impressions, that the main process of photoaging in Asians involves pigmentary changes, rather than wrinkling. However, no study has been performed to confirm this belief. Risk factors for skin wrinkles and their relative risks in Korean skin [2] Various factors such as age, sun-exposure, and smoking are known to be important risk factors for wrinkles. However, the relative risks of each factor on wrinkles in the brown skin of Asians have not been investigated, and they could differ from those in Caucasians. An evaluation system for skin wrinkling is necessary for Asian skin [3]. Thus, we developed an eight-point photographic scale for assessing wrinkles in both Korean genders [2]. This scale can probably be applied to the populations of other Asian countries, at least to the Japanese and Chinese. The pattern of wrinkles in both genders appears to be similar. Age Age is an important risk factor for wrinkling in Asians, as in Caucasians. Korean subjects in their 60s showed a 12-fold increased risk of wrinkling, while subjects in their 70s have a 56-fold increased risk compared with young age group. UV light It is well known that the UV component in sunlight can cause and accelerate photoaging. The pigmented skin of Asian may better protect skin from acute and chronic UV damage. However, we found a strong association between sun-exposure and the development of wrinkling in Koreans. It was found that sun exposure of more than 5 h per day was associated with a 4.8-fold increased risk in wrinkling versus less than 2 h of sun-exposure in Koreans. Estrogen deficiency Korean females have more wrinkles than men, after controlling for age, sun exposure, and smoking, it was found that they have a 3.6-fold increased risk of developing wrinkles than their male counterparts [2]. It has also been reported, that the relative risk for wrinkling in women is higher than in men as for in white Caucasians [4]. The reason why women show more wrinkles remains to be determined. It is possible that a reduction in skin collagen because of estrogen deficiency in postmenopausal woman may aggravate wrinkling severity. Korean women with more than 10 years since menopause showed a 3.9-fold higher risk of wrinkling than the women 5 years of beyond menopause [5]. We demonstrated that women with a history of HRT have a significantly lower risk, more specifically, one fifth of the risk of facial wrinkling relative to those who had no history of HRT. Interestingly, we found that wrinkle severity significantly increased with an increasing number of full term pregnancies. The relative risk for severe wrinkling is increased by approximately 1.8-fold per full term pregnancy. Smoking It is known that smoking causes skin wrinkling in Caucasians, and that it plays no role in Blacks [6, 7]. Koreans with have a smoking history of more than 30 pack years showed a more than 2.8-fold increased risk of wrinkles [2]. The relative risks of wrinkles associated with a 30,50 pack-years history of smoking were 2.8- and 5.5-fold, respectively. Dyspigmentation in Asian skin To follow pigmentary changes, six photographic standards for both genders were developed for Korean skin, to produce a 6-point scale [2, 8]. Hyperpigmented spots, mostly lentigines, were prominent among women, while seborrheic keratosis tended to be more prominent in men. Seborrheic keratosis in Korean men Seborrheic keratoses (SKs) are benign cutaneous tumors. They have diverse clinical and histopathological appearances and are very common in the elderly (over 50 years old). The etiology of SKs is not well understood, although patients with a great number of lesionsshow a familial trait with an autosomal dominant pattern, and human papilloma virus has been suggested as possible cause because of verrucous appearance of the lesions. Exposure to sunlight has been suggested to be a risk factor for SKs. However, there is still some debate in terms of the role of sunlight. Recently, we have investigated the clinical characteristics of SKs and relationship between SKs and sunlight exposure in Korean males [9]. The prevalence of SKs in Koreans increases with age; it rose from 78.9% at 40 years, to 93.9% at 50 years and 98.7% in those over 60 years. Exposed areas, i.e. the face, neck and dorsum of the hands, demonstrate a significant increase in the prevalence of SKs by decade, whereas partly exposed areas, although SKs tended to increase in prevalence with age, this trend was not significant. When the estimated body surface area (BSA) is taken into account, the number of SKs on both the face and dorsum of the hands (0.51 ± 0.08 per 1% BSA) was over-represented compared with the trunk. SKs were also concentrated on the neck (0.38 ± 0.07 per 1% BSA) and in the V-area (0.47 ± 0.09 per 1% BSA). Outer forearms also showed 3-fold more SKs per unit area than neighboring arms and inner forearms, which are classified as partly exposed area (0.09 ± 0.02, 0.03 ± 0.01, respectively). The total area covered by SKs on exposed area also became significantly larger with aging than on intermittently exposed areas. These results indicate that exposure to sunlight might be related to SK growth. Our results indicated that excessive sun exposure is an independent risk factor of SKs. After controlling for age, smoking, and skin type, subjects with a sun exposure history of more than 6 hours per day showed a 2.28-fold increased risk of having severe SKs (n , 6) compared with those exposed for less that 3 h per day. These findings indicated that sun-exposure may play an important role in SK development. In summary, SKs are very common in Korean males and represent one of the major pigmentary problems. SKs concentrate on exposed skin, especially on the face and dorsum of the hands. Both age and lifetime cumulative sunlight exposure are important contributing factors and may work in a synergistic manner. Conclusion Many people tend to believe that wrinkles are not a prominent feature of Asian photoaged skin, and that dyspigmentation is a major manifestation in Asian skin. Contrary to this impression, wrinkling is also a major problem in the photoaged skin of Asians, and Korean people showing severe pigmentary changes usually tend to have severe wrinkles. In conclusion, the wrinkling patterns and pigmentary changes of photoaged skin in East Asians differ from those of Caucasians, and the relative risks of aggravating factors may be different from those of Caucasian skin. References 1.,Gilchrest, B.A. Skin aging and photoaging: an overview. J. Am. Acad. Dermatol. 21, 610,613 (1989). 2.,Chung, J.H. et al. Cutaneous photodamage in Koreans: influence of sex, sun exposure, smoking, and skin color. Arch. Dermatol. 137, 1043,1051 (2001). 3.,Griffiths, C.E. et al. A photonumeric scale for the assessment of cutaneous photodamage. Arch. Dermatol. 128, 347,351 (1992). 4.,Ernster, V.L. et al. Facial wrinkling in men and women, by smoking status. Am. J. Public Health. 85, 78,82 (1995). 5.,Youn, C.S. et al. Effect of pregnancy and menopause on facial wrinkling in women. Acta Derm. Venereol. 83, 419,424 (2003). 6.,Kadunce, D.P. et al. Cigarette smoking: risk factor for premature facial wrinkling. Ann. Intern. Med. 114, 840,844 (1991). 7.,Allen, H.B., Johnson, B.L. and Diamond, S.M. Smoker's wrinkles? JAMA. 225, 1067,1069 (1973). 8.,Chung, J.H. Photoaging in Asians. Photodermatol. Photoimmunol. Photomed. 19, 109,121 (2003). 9.,Kwon, O.S. et al. Seborrheic keratosis in the Korean males: causative role of sunlight. Photodermatol. Photoimmunol. Photomed. 19, 73,80 (2003). [source]


    Refinement of an osteoporosis risk-assessment questionnaire for use in community pharmacy

    INTERNATIONAL JOURNAL OF PHARMACY PRACTICE, Issue 5 2008
    Lee Ser Poh pharmacy practice advanced student
    Objective To explore the influence of bone mineral density (BMD) tests in osteoporosis risk categorisation in community pharmacies, and to develop a simple tool for pharmacists to use as a pre-BMD test screen. Method A secondary data analysis was conducted on the responses of 193 participants to a risk-assessment questionnaire, used in previous osteoporosis research that included a BMD test. To explore the impact of the BMD test on pharmacists' categorisation of risk, the researchers made an independent assessment based on responses of the questionnaire. The influence of risk factors on BMD scores/bone status was explored using multiple and logistic regression respectively. Key findings A total of responses of 193 participants were available for study, with 113 in the BMD group and 80 from the non-BMD group. In the BMD group, both researchers and pharmacists identified a similar proportion of patients in the moderate/high-risk category when BMD results were incorporated in the risk assessments (X2 = 0.78, degrees of freedom (df) = 1, 0.3 < P < 0.5). A statistically significant difference in risk categorisation was found between the pharmacists and researchers in the non-BMD group (X2 = 23.9, df = 1, P < 0.001). Risk factors identified to be significantly affecting BMD and of use for identifying patients at high risk for osteopenia/osteoporosis were age, weight, postmenopause and absence of hormone replacement therapy (HRT). These four factors were used to construct a simple risk index to guide pharmacists' initial risk categorisation. Conclusion The findings of this study suggested that BMD testing may increase the effectiveness of risk assessments and enhance the screening procedures in the community pharmacy. The simple risk index could serve as a pre-BMD test screen, with a BMD test recommended when necessary. A refined risk-assessment questionnaire could serve to guide pharmacists in directing individualised counselling and advice for at-risk patients, through identification of modifiable risk factors and conditions. [source]


    Differing Patterns of Antiresorptive Pharmacotherapy in Nursing Facility Residents and Community Dwellers

    JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 8 2005
    Carolyn M. Jachna MD
    Objectives: Little is known about differences between current patterns of antiresorptive therapy (ART) use in nursing facility (NF) residents and by community-dwelling older adults (CDs). ART use was compared in older NF residents and CDs. Design: Cross-sectional analysis. Setting: Kansas Medicaid files from May 2000 through April 2001. Participants: Women aged 65 and older having at least 9 months of data as a CD or NF resident. Measurements: Pharmacy claims were used to identify any ART prescription, including hormone replacement therapy (HRT), a bisphosphonate, raloxifene, or calcitonin. Demographic and clinical variables were identified from the claims files. Factors associated with ART use in bivariate analyses were entered into logistic regression models. Similar analyses were performed for bisphosphonate use among non-estrogen replacement therapy (non-ERT) ARTs (excluding HRT). Results: The final study sample (N=2,289) included 898 NF (mean age 85.2) residents and 1,391 CDs (mean age 76.6). CDs were more likely to receive any ART (24.5%) than NF residents (19.6%). After adjustment for potential confounders, NF residents aged 65 to 84 were less likely (odds ratio (OR)=0.61, 95% confidence interval (CI)=0.44,0.85) to receive ART than CDs of the same age. Conversely, of those aged 85 and older, NF residents were more likely than CDs to receive ART (OR=1.96, 95% CI=1.18,3.25). Calcitonin was the most common non-ERT ART prescribed for NF residents, whereas bisphosphonates were more often prescribed for CDs. Conclusion: Underusage of ART is common in NF and CD cohorts. NF residents are less likely to receive bisphosphonates and more likely to receive calcitonin, for which efficacy is less clear. Further research is needed to identify factors influencing ART prescribing and selection of specific ARTs in different settings. [source]


    Hormone Use and Cognitive Performance in Women of Advanced Age

    JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 2 2004
    J. Galen buckwalter PhD
    Objectives: To explore the association between hormone replacement therapy (HRT) and cognitive performance in a group of elderly women (,75) using a battery of well-standardized neuropsychological instruments. Design: Equivalent samples from existing cohort. Setting: Healthcare provider organization. Participants: All women enrolled were participants in an ongoing study of the association between HRT and the prevalence and incidence of dementia. Prescription records were used to establish HRT status. Fifty-eight users and 47 nonusers of HRT participated in this substudy. Measurements: Given previous reports that HRT has a positive effect on verbal memory, the California Verbal Learning Test and the Logical Memory Test were used as primary outcomes. A range of validated tests that assess other cognitive domains was also included. Results: There were no significant differences between users and nonusers of HRT on any cognitive measures. Conclusion: Given equivalent groups of users and nonusers of HRT no support was found for the hypothesis that use of HRT improves cognitive performance in older women. [source]


    Effect of Teriparatide {rhPTH(1-34)} on BMD When Given to Postmenopausal Women Receiving Hormone Replacement Therapy

    JOURNAL OF BONE AND MINERAL RESEARCH, Issue 2 2006
    Louis G Ste-Marie
    Abstract The effects of teriparatide when given in combination with HRT were studied in postmenopausal women with low bone mass or osteoporosis. The data provide evidence that the adverse event profile for combination therapy with teriparatide + HRT together is consistent with that expected for each treatment alone and that the BMD response is greater than for HRT alone. Introduction: Teriparatide {rhPTH(1-34)}, given as a once-daily injection, activates new bone formation in patients with osteoporosis. Hormone replacement therapy (HRT) prevents osteoporosis by reducing bone resorption and formation. Combination therapy with these two compounds, in small clinical trials, increased BMD and reduced vertebral fracture burden. The purpose of this study was to determine whether teriparatide provided additional effect on BMD when given in combination with HRT. Materials and Methods: A randomized, double-blind, placebo-controlled study was conducted in postmenopausal women with either low bone mass or osteoporosis. Patients were randomized to placebo subcutaneous plus HRT (n = 125) or teriparatide 40 ,g/day (SC) plus HRT (TPTD40 + HRT; n = 122) for a median treatment exposure of 13.8 months. Approximately one-half of the patients in each group were pretreated with HRT for at least 12 months before randomization. Patients received 1000 mg calcium and 400,1200 IU of vitamin D daily as oral supplementation. BMD was measured by DXA. Results: Compared with HRT alone, TPTD40 + HRT produced significant (p < 0.001) increases in spine BMD (14% versus 3%), total hip (5.2% versus 1.6%), and femoral neck (5.2% versus 2%) at study endpoint. BMD, in whole body and ultradistal radius, was higher, and in the one-third distal radius was lower, in the combination therapy but not in the HRT group. Serum bone-specific alkaline phosphatase and urinary N-telopeptide/Cr were increased significantly (p < 0.01) in the women receiving TPTD40 + HRT compared with HRT. A similar profile of BMD and bone markers was evident in both randomized patients as well as in subgroups of patients not pretreated or pretreated with HRT. Patients tolerated both the treatments well. Nausea and leg cramps were more frequently reported in the TPTD40 + HRT group. Conclusions: Adding teriparatide, a bone formation agent, to HRT, an antiresorptive agent, provides additional increases in BMD beyond that provided by HRT alone. The adverse effects of teriparatide when added to HRT were similar to the adverse effects described for teriparatide administered alone. Whether teriparatide was initiated at the same time as HRT or after at least 1 year on HRT, the incremental increases over HRT alone were similar. [source]


    Effect of Hormone Replacement Therapy on Bone Quality in Early Postmenopausal Women

    JOURNAL OF BONE AND MINERAL RESEARCH, Issue 6 2003
    Ep Paschalis PhD
    Abstract HRT is an effective prophylaxis against postmenopausal bone loss. Infrared imaging of paired iliac crest biopsies obtained at baseline and after 2 years of HRT therapy demonstrate an effect on the mineral crystallinity and collagen cross-links that may affect bone quality. Several studies have demonstrated that hormonal replacement therapy (HRT) is an effective prophylaxis against postmenopausal bone loss, although the underlying mechanisms are still debated. Infrared spectroscopy has been used previously for analyzing bone mineral crystallinity and three-dimensional structures of collagen and other proteins. In the present study, the technique of Fourier transform infrared microscopic imaging (FTIRI) was used to investigate the effect of estrogen on bone quality (arbitrarily defined as mineral/matrix ratio, mineral crystallinity/maturity, and relative ratio of collagen cross-links [pyridinoline/deH-DHLNL]) at the ultrastructural level, in mineralized, thin tissue sections from double (before and after administration of HRT regimen; cyclic estrogen and progestogen [norethisterone acetate]) iliac crest biopsy specimens from 10 healthy, early postmenopausal women who were not on any medication with known influence on calcium metabolism. FTIRI allows the analysis of undemineralized thin tissue sections (each image analyzes a 400 × 400 ,m2 area with a spatial resolution of ,6.3 mm). For each bone quality variable considered, the after-treatment data exhibited an increase in the mean value, signifying definite changes in bone properties at the molecular level after HRT treatment. Furthermore, these findings are consistent with suppressed osteoclastic activity. [source]


    Smoking May Impair the Bone Protective Effects of Nutritional Calcium: A Population-Based Approach,

    JOURNAL OF BONE AND MINERAL RESEARCH, Issue 6 2003
    Joonas Sirola PhD
    Abstract Postmenopausal women were randomly selected to investigate the effects of smoking on prevention of bone loss with nutritional calcium. DXA was performed twice, and smoking and calcium intake habits were inquired through the mail in 954 women. Smoking dampened the bone protective effects of nutritional calcium. This may reflect the pathophysiology underlying smoking-induced bone loss postmenopause. This study evaluated the effect of smoking on the bone protective properties of nutritional calcium. Of the random sample of 954 peri- and postmenopausal women selected from the Osteoporosis Risk Factor and Prevention (OSTPRE) study cohort (n = 13,100) in Kuopio, Finland, 182 had smoked at some time (ever smokers) and 772 had never smoked. Women were divided in tertiles according to self-reported dairy nutritional calcium intake (mg/day): <648 (1st), 648-927 (2nd), >927 (3rd). Bone mineral density at lumbar spine (LS) and femoral neck (FN) was measured with DXA at baseline in 1989-1991 and at the 5-year follow-up in 1994-1997. In a linear regression model, nutritional calcium intake did not predict annual bone loss in smokers. These results were similar in the subanalysis on 71 current smokers (at both baseline and 5-year measurements) and on 85 past smokers. In never smokers, a statistically significant linear trend was observed between calcium intake and annual bone loss at LS, but at FN only after adjustment for age, weight, hormone replacement therapy (HRT), and other covariates. In analysis of covariance (ANCOVA), no differences in bone loss rate were observed between calcium intake tertiles among smokers. In nonsmokers, the annual bone loss rate was lower in the second (,0.41%) and the third (,0.35%) tertile compared with the first tertile (,0.61%) at LS (p < 0.05) and lower in the third tertile (,0.55%) than in first tertile (,0.72%) at FN after adjustment for age, weight, HRT, and other covariates (p < 0.05). When smokers were added to the nonsmoker group, the differences in bone loss rate between calcium intake tertiles disappeared. In addition, in ANCOVA, the term of interaction between smoking and calcium intake was statistically significant at LS only. In conclusion, smoking seems to impair the bone protective effects of nutritional calcium in postmenopausal women, more clearly in LS than FN. [source]


    Growth Hormone Increases Bone Mineral Content in Postmenopausal Osteoporosis: A Randomized Placebo-Controlled Trial

    JOURNAL OF BONE AND MINERAL RESEARCH, Issue 3 2003
    Kerstin Landin-Wilhelmsen
    Abstract Eighty osteoporotic, postmenopausal women, 50,70 years of age, with ongoing estrogen therapy (HRT), were randomized to recombinant human growth hormone (GH), 1.0 U or 2.5 U/day, subcutaneous, versus placebo. This study was double-blinded and lasted for 18 months. The placebo group then stopped the injections, but both GH groups continued for a total of 3 years with GH and followed for 5 years. Calcium (750 mg) and vitamin D (400 U) were given to all patients. Bone mineral density and bone mineral content were measured with DXA. At 18 months, when the double-blind phase was terminated, total body bone mineral content was highest in the GH 2.5 U group (p = 0.04 vs. placebo). At 3 years, when GH was discontinued, total body and femoral neck bone mineral content had increased in both GH-treated groups (NS between groups). At 4-year follow-up, total body and lumbar spine bone mineral content increased 5% and 14%, respectively, for GH 2.5 U (p = 0.01 and p = 0.0006 vs. placebo). Femoral neck bone mineral density increased 5% and bone mineral content 13% for GH 2.5 U (p = 0.01 vs. GH 1.0 U). At 5-year follow-up, no differences in bone mineral density or bone mineral content were seen between groups. Bone markers showed increased turnover. Three fractures occurred in the GH 1.0 U group. No subjects dropped out. Side effects were rare. In conclusion, bone mineral content increased to 14% with GH treatment on top of HRT and calcium/vitamin D in postmenopausal women with osteoporosis. There seems to be a delayed, extended, and dose-dependent effect of GH on bone. Thus, GH could be used as an anabolic agent in osteoporosis. [source]


    Hormone Replacement Therapy Dissociates Fat Mass and Bone Mass, and Tends to Reduce Weight Gain in Early Postmenopausal Women: A Randomized Controlled 5-Year Clinical Trial of the Danish Osteoporosis Prevention Study,

    JOURNAL OF BONE AND MINERAL RESEARCH, Issue 2 2003
    LB Jensen MD
    Abstract The aim of this study was to study the influence of hormone replacement therapy (HRT) on weight changes, body composition, and bone mass in early postmenopausal women in a partly randomized comprehensive cohort study design. A total of 2016 women ages 45,58 years from 3 months to 2 years past last menstrual bleeding were included. One thousand were randomly assigned to HRT or no HRT in an open trial, whereas the others were allocated according to their preferences. All were followed for 5 years for body weight, bone mass, and body composition measurements. Body weight increased less over the 5 years in women randomized to HRT (1.94 ± 4.86 kg) than in women randomized to no HRT (2.57 ± 4.63, p = 0.046). A similar pattern was seen in the group receiving HRT or not by their own choice. The smaller weight gain in women on HRT was almost entirely caused by a lesser gain in fat. The main determinant of the weight gain was a decline in physical fitness. Women opting for HRT had a significantly lower body weight at inclusion than the other participants, but the results in the self-selected part of the study followed the pattern found in the randomized part. The change in fat mass was the strongest predictor of bone changes in untreated women, whereas the change in lean body mass was the strongest predictor when HRT was given. Body weight increases after the menopause. The gain in weight is related to a decrease in working capacity. HRT is associated with a smaller increase in fat mass after menopause. Fat gain protects against bone loss in untreated women but not in HRT-treated women. The data suggest that women's attitudes to HRT are more positive if they have low body weight, but there is no evidence that the conclusions in this study are skewed by selection bias. [source]


    Effects of Genistein and Hormone-Replacement Therapy on Bone Loss in Early Postmenopausal Women: A Randomized Double-Blind Placebo-Controlled Study,

    JOURNAL OF BONE AND MINERAL RESEARCH, Issue 10 2002
    Nunziata Morabito
    Abstract The natural isoflavone phytoestrogen genistein has been shown to stimulate osteoblastic bone formation, inhibit osteoclastic bone resorption, and prevent bone loss in ovariectomized rats. However, no controlled clinical trial has been performed so far to evaluate the effects of the phytoestrogen on bone loss in postmenopausal women. We performed a randomized double-blind placebo-controlled study to evaluate and compare with hormone-replacement therapy (HRT) the effect of the phytoestrogen genistein on bone metabolism and bone mineral density (BMD) in postmenopausal women. Participants were 90 healthy ambulatory women who were 47,57 years of age, with a BMD at the femoral neck of <0.795 g/cm2. After a 4-week stabilization on a standard fat-reduced diet, participants of the study were randomly assigned to receive continuous HRT for 1 year (n = 30; 1 mg of 17,-estradiol [E2] combined with 0.5 mg of norethisterone acetate), the phytoestrogen genistein (n = 30; 54 mg/day), or placebo (n = 30). Urinary excretion of pyridinoline (PYR) and deoxypyridinoline (DPYR) was not significantly modified by placebo administration either at 6 months or at 12 months. Genistein treatment significantly reduced the excretion of pyridinium cross-links at 6 months (PYR = ,54 ± 10%; DPYR = ,55 ± 13%; p < 0.001) and 12 months (PYR = ,42 ± 12%; DPYR = ,44 ± 16%; p < 0.001). A similar and not statistically different decrease in excretion of pyridinium cross-links was also observed in the postmenopausal women randomized to receive HRT. Placebo administration did not change the serum levels of the bone-specific ALP (B-ALP) and osteocalcin (bone Gla protein [BGP]). In contrast, administration of genistein markedly increased serum B-ALP and BGP either at 6 months (B-ALP = 23 ± 4%; BGP = 29 ± 11%; p < 0.005) or at 12 months (B-ALP = 25 ± 7%; BGP = 37 ± 16%; p < 0.05). Postmenopausal women treated with HRT had, in contrast, decreased serum B-ALP and BGP levels either at 6 months (B-ALP = ,17 ± 6%; BGP = ,20 ± 9%; p < 0.001) or 12 months (B-ALP = ,20 ± 5%; BGP = ,22 ± 10%; p < 0.001). Furthermore, at the end of the experimental period, genistein and HRT significantly increased BMD in the femur (femoral neck: genistein = 3.6 ± 3%, HRT = 2.4 ± 2%, placebo = ,0.65 ± 0.1%, and p < 0.001) and lumbar spine (genistein = 3 ± 2%, HRT = 3.8 ± 2.7%, placebo = ,1.6 ± 0.3%, and p < 0.001). This study confirms the genistein-positive effects on bone loss already observed in the experimental models of osteoporosis and indicates that the phytoestrogen reduces bone resorption and increases bone formation in postmenopausal women. [source]


    Does Hormone-Replacement Therapy Prevent Fractures in Early Postmenopausal Women?,

    JOURNAL OF BONE AND MINERAL RESEARCH, Issue 3 2002
    Kaisa M. Randell M.D.
    Abstract The purpose of this population-based prospective cohort study was to examine the effect of hormone-replacement therapy (HRT) on the risk of fractures. The study population consisted of 7217 postmenopausal women aged 47-56 years (mean, 53.3 years) at baseline from data taken from the Kuopio Osteoporosis Risk Factor and Prevention Study (OSTPRE) in Finland. We compared fracture incidences between HRT users and nonusers. A total of 679 (9.4%) women recorded validated fractures during the 5-year follow-up. Of these, 268 (39%) women had a distal forearm fracture. Two thousand six hundred seventy women (37%) had used HRT >6 months during the follow-up,one-half of them continuously. The relative risk, estimated as hazard ratio with Cox regression, was 0.69 (95% CI, 0.58-0.82) for any fracture and 0.49 (0.36-0.66) for distal forearm fracture among HRT users as compared with never-users. After adjusting for age, body mass index (BMI), number of chronic health disorders, fracture history, and time since menopause (independent risk factors) the corresponding risks were 0.67 (0.55-0.81) and 0.53 (0.37-0.74), respectively. The respective adjusted risks for continuous HRT users were 0.62 (0.48-0.79) and 0.41 (0.26-0.67). The adjusted risk of other than distal forearm fracture was 0.74 (0.55-0.98). The results suggest that HRT has a beneficial effect on prevention of fractures in general and on that of distal forearm fracture in particular in early postmenopausal women. [source]


    The Association Between Heel Ultrasound and Hormone Replacement Therapy Is Modulated by a Two-Locus Vitamin D and Estrogen Receptor Genotype

    JOURNAL OF BONE AND MINERAL RESEARCH, Issue 6 2000
    Yves Giguère
    Abstract Evidence supports the role of estrogen deprivation in the process of bone remodeling and increased risk of fracture in postmenopausal women but little is known about the genetic basis of individual differences in response to therapy. In a cross-sectional study, 425 ambulatory postmenopausal French-Canadian women from Quebec (age range, 42,85 years old) were genotyped for a common Bsm I polymorphism at the vitamin D receptor (VDR) gene as well as a Pvu II polymorphism in the estrogen receptor (ESR1) gene. Heel ultrasound was determined by right calcaneal quantitative ultrasound (QUS) and results were expressed as an age- and-weight-adjusted stiffness index (heel SI z score). Our aim was to investigate the interaction between hormone-replacement therapy (HRT) and receptor genotypes in an effect on heel SI. Notably, a two-locus genotype (VDR-bb/ESR-PP) present in 9.5% of women was responsible for over 30% of the total HRT-related heel SI difference in the whole sample. Women bearing this combined VDR/ESR1 genotype who received HRT for more than 5 years had a 21% (1.25 SD) greater heel SI (p = 0.002) than those bearing the same genotype but who received HRT for <5 years. This may translate into a 2- to 3-fold difference in the risk of fracture. Although follow-up studies are needed, our findings suggest that QUS of the heel in postmenopausal women taking HRT is affected by variation in VDR and ESR1 loci, jointly. [source]


    Novel Measures of Heart Rate Variability Predict Cardiovascular Mortality in Older Adults Independent of Traditional Cardiovascular Risk Factors: The Cardiovascular Health Study (CHS)

    JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 11 2008
    PHYLLIS K. STEIN Ph.D.
    Background: It is unknown whether abnormal heart rate turbulence (HRT) and abnormal fractal properties of heart rate variability identify older adults at increased risk of cardiovascular death (CVdth). Methods: Data from 1,172 community-dwelling adults, ages 72 ± 5 (65,93) years, who participated in the Cardiovascular Health Study (CHS), a study of risk factors for CV disease in people ,65 years. HRT and the short-term fractal scaling exponent (DFA1) derived from 24-hour Holter recordings. HRT categorized as: normal (turbulence slope [TS] and turbulence onset [TO] normal) or abnormal (TS and/or TO abnormal). DFA1 categorized as low (,1) or high (>1). Cox regression analyses stratified by Framingham Risk Score (FRS) strata (low = <10, mid = 10,20, and high >20) and adjusted for prevalent clinical cardiovascular disease (CVD), diabetes, and quartiles of ventricular premature beat counts (VPCs). Results: CVdths (N = 172) occurred over a median follow-up of 12.3 years. Within each FRS stratum, low DFA1 + abnormal HRT predicted risk of CVdth (RR = 7.7 for low FRS; 3.6, mid FRS; 2.8, high FRS). Among high FRS stratum participants, low DFA1 alone also predicted CVdth (RR = 2.0). VPCs in the highest quartile predicted CVdth, but only in the high FRS group. Clinical CV disease predicted CVdth at each FRS stratum (RR = 2.9, low; 2.6, mid; and 1.9, high). Diabetes predicted CVdth in the highest FRS group only (RR = 2.2). Conclusions: The combination of low DFA1 + abnormal HRT is a strong risk factor for CVdth among older adults even after adjustment for conventional CVD risk measures and the presence of CVD. [source]


    Relationship Between Heart Rate Turbulence and Heart Rate, Heart Rate Variability, and Number of Ventricular Premature Beats in Coronary Patients

    JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 7 2004
    IWONA CYGANKIEWICZ M.D., Ph.D.
    Introduction: Heart rate variability (HRV) illustrates regulation of the heart by the autonomic nervous system whereas heart rate turbulence (HRT) is believed to reflect baroreflex sensitivity. The aim of this study was to determine the association between HRT and HRV parameters and the relationship between HRT parameters and heart rate and number of ventricular premature beats (VPBs) used to calculate HRT parameters. Methods and Results: In 146 patients (117 males and 29 females; mean age 62 years) with coronary artery disease, a 24-hour ECG Holter monitoring was performed to calculate mean heart rate (RR interval), number of VPBs, time- and frequency-domain HRV parameters and two HRT parameters: turbulence onset (TO) and turbulence slope (TS). Univariate and multivariate regression analyses were performed to evaluate the association between tested parameters. Significant correlation between TS and mean RR interval was observed (r = 0.42; p < 0.001), while no association for TO vs. RR interval was found. TS values were significantly higher in patients with less than 10 VPBs/24 hours than in patients with more frequent VPBs. Significant associations between HRT and HRV parameters were found with TS showing stronger correlation with HRV parameters than TO (r value ranging from 0.35 to 0.62 for TS vs. ,0.16 to ,0.38 for TO). Conclusion: HRT parameters correlate strongly with HRV parameters indicating that HRT should be considered as a reflection of both baroreceptors response and overall autonomic tone. Heart rate dependence of turbulence slope indicates the need to adjust this parameter for heart rate. (J Cardiovasc Electrophysiol, Vol. 15, pp. 731-737, July 2004) [source]


    Aerobic biodegradation of MtBE in an upflow fixed bed reactor

    JOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 6 2009
    Emma Bianchi
    Abstract BACKGROUND: An aerobic upflow fixed bed reactor (UFBR) was densely colonized by a bacterial consortium, obtained from gasoline polluted waters, able to mineralize MtBE and BTEX. The system was studied in order to determine its capability to degrade the MtBE present in prepared solutions and in real contaminated aquifers and was operating for more than a year. RESULTS: Efficient colonization of the reactor took about 50 days, utilizing bacteria grown in continuous culture in a fermenter connected to the UFBR. During the study the influence of feed concentration of MtBE, temperature and hydraulic retention time (HRT) was analyzed. The system, running at 18 °C on synthetic medium, was fed at an influent MtBE concentration of 27.8 mg L,1 with HRT of 5 h showing 99.98% of MtBE degradation. When working with polluted groundwater, the system achieved 100% BTEX degradation and 99.34% MtBE degradation. CONCLUSION: The UFBR was tested on synthetic medium spiked with MtBE and on groundwater contaminated with MtBE and BTEX at concentrations of 50,60 ppm and a few ppm, respectively. The reactor responded efficiently showing great flexibility and capability of adjustment to different operating conditions with MtBE degradation of nearly 100%. Copyright © 2009 Society of Chemical Industry [source]


    The beneficial role of intermediate clarification in a novel MBR based process for biological nitrogen and phosphorus removal

    JOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 5 2009
    MinGu Kim
    Abstract BACKGROUND: A novel membrane bioreactor (MBR) is described, employing an intermediate clarifier. Unlike the established function of a final clarifier in a conventional biological nutrient removal system, the role of an intermediate clarifier has rarely been studied. Thus, this work focused on explaining the fate of nutrients in the intermediate clarifier, as influenced by the hydraulic retention time (HRT) of the preceding anaerobic bioreactor. RESULTS: The system was tested with two different anaerobic/anoxic/aerobic biomass fractions of 0.25/0.25/0.5 (run 1) and 0.15/0.35/0.45 (run 2) using synthetic wastewater. The major findings of the study were that phosphorus (P) removal was affected by the role of the intermediate clarifier. In run 1, P was removed at a rate 0.16 g d,1 in the intermediate clarifier while in run 2, additional P was released at 0.49 g d,1. The nitrogen (N) removal efficiencies were 74 and 75% for runs 1 and 2 respectively, while P removal was 91 and 96%. P uptake by denitrifying phosphate accumulating organisms (DPAOs) accounted for 41,52% of the total uptake in the MBR. CONCLUSIONS: This study found that the intermediate clarifier assisted chemical oxygen demand (COD), N, and P removal. With respect to the fate of P, the intermediate clarifier functioned as an extended anaerobic zone when the HRT of the preceding anaerobic zone was insufficient for P release, and as a pre-anoxic zone when the anaerobic HRT was adequate for P release. Copyright © 2008 Society of Chemical Industry [source]


    Wastewater treatment for production of H2S-free biogas

    JOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 8 2008
    Sk Z Ahammad
    Abstract BACKGROUND: In anaerobic wastewater treatment processes, the presence of sulfate-reducing bacteria (SRB) produces H2S. Many techniques are being used to remove H2S from biogas to obtain H2S-free biogas but none of those are cost effective or efficient enough to remove the H2S completely. The objective of the present study was to introduce some changes/modifications to the process parameters of the wastewater treatment operation to eliminate SRB from the system. RESULTS: The growth of SRB was found to be completely suppressed under thermophilic conditions (55 °C) but not at 37 °C. H2S-free biogas containing 56.5% methane was obtained at 55 °C after 180 days of treatment. The effect of higher concentrations of volatile fatty acids (VFAs) on the growth of SRB and methanogens at 37 °C and 55 °C were also studied. At higher VFA concentrations, SRB outgrew the methanogens at 37 °C but at 55 °C the situation was found to be reversed. For continuous operation at 55 °C and low dilution rate (0.0075 h,1), SRB was suppressed and biogas having 29% methane but free of H2S was obtained. CONCLUSION: Operating the reactor at high temperature (550C) and low hydraulic retention time (HRT) can result in the production of H2S-free biogas, with a high concentration of methane. Copyright © 2008 Society of Chemical Industry [source]


    Influence of COD:N:P ratio on dark greywater treatment using a sequencing batch reactor

    JOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 5 2008
    Vijayaraghavan Krishnan
    Abstract The recycling of greywater is an integral part of a water management system owing to the scarcity of fresh water resources. This article explores the effectiveness of an aerobic sequencing batch reactor in treating nutrient-deficit and nutrient-spiked dark greywater for agricultural reuse. The dark greywater in the present investigation had a COD:N:P ratio of 100:1.82:0.76, while the preferred ratio for biological oxidation is 100:5:1 (COD, chemical oxygen demand). The aerobic oxidation of nutrient-deficit and nutrient-spiked dark greywater with a COD:N:P ratio of 100:2.5:0.5; 100:3.5:0.75 and 100:5:1 resulted in outlet COD values of 64; 35; 15 and 12 mg L,1, with a corresponding BOD5 value of 37; 22; 10 and 8 mg L,1 at 36 h hydraulic retention time (HRT). Hence treatment of nutrient-added dark greywater at a COD:N:P ratio 100:3.5:0.75 and 100:5:1 for 36 h HRT complied with the Malaysian discharge standards for agricultural activities. Treated greywater has the potential for consideration as a resource, since it can be used as a supplement or replacement for potable water in landscape irrigation and other agricultural activities in rural and urban areas. Moreover, the level of greywater treatment is dictated by the final water quality requirement. Copyright © 2008 Society of Chemical Industry [source]