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Increasing Duration (increasing + duration)

Distribution by Scientific Domains

Medical Sciences	65%
Life Sciences	21%
3 Other Domains	14%

Selected Abstracts

How hypoglycaemia can affect the life of a person with diabetes

DIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 2 2008
Brian M. Frier
Abstract Hypoglycaemia is the commonest side-effect of insulin treatment for diabetes, and is the single greatest barrier to achieving and maintaining good glycaemic control. Severe hypoglycaemia (requiring assistance for recovery) is associated with significant morbidity and is feared by most people with type 1 diabetes and their families. It causes stress and anxiety and may influence self-management and glycaemic control. The annual prevalence of severe hypoglycaemia is around 30% in people with type 1 diabetes, and is higher in those with risk factors such as strict glycaemic control, impaired awareness of hypoglycaemia and increasing duration of diabetes. It is also common during sleep (nocturnal hypoglycaemia). Neurological manifestations include coma, convulsions, transient hemiparesis and stroke, while reduced consciousness and cognitive dysfunction may cause accidents and injuries. Cardiac events may be precipitated such as arrhythmias, myocardial ischaemia and cardiac failure. Hypoglycaemia can affect all aspects of life, including employment, driving, recreational activities involving exercise, and travel, and measures should be taken in all of these situations to avoid this potentially dangerous side-effect of insulin therapy. Copyright © 2007 John Wiley & Sons, Ltd. [source]

Variability in responses to thermal stress in parasitoids

ECOLOGICAL ENTOMOLOGY, Issue 6 2008
GAËLLE AMICE
Abstract 1.,To study phenotypic effects of stress, a stress is applied to cohorts of organisms with an increasing intensity. In the absence of mortality the response of traits will be a decreasing function of stress intensity because of increasing physiological costs. We call such decreasing functions type A responses. 2.,However, when stress caused mortality, some studies have found that for high stress intensities, survivors performed as well as control individuals (type B responses). We proposed that type A responses are caused by the physiological cost of stress whereas type B responses are caused by a mixture of physiological costs and selection. 3.,The present study exposed Aphidius picipes wasps to an increasing duration of cold storage (cold stress), and obtained variable responses as predicted when both physiological costs and selection of resistant individuals determine the outcome. 4.,When cold storage of parasitoids for biological control is desirable, research should be carried out to find (i) the temperature regime and duration of storage and (ii) the least sensitive stage for storage to minimise losses from mortality and reduction of fitness of survivors. 5.,Selection by cold stress as observed in the present study could result in rapid adaptation of populations exposed to such stress. [source]

Accumulation of heterocyclic nitrogen in humified organic matter: a 15N-NMR study of lowland rice soils

EUROPEAN JOURNAL OF SOIL SCIENCE, Issue 3 2000
N. Mahieu
Summary Recent intensification of cropping and the attendant longer submergence of the soil for lowland rice in tropical Asia appear to have altered the nature of the soil organic matter, and perhaps also nutrient cycling. To identify the dominant forms of organic nitrogen in the soils we extracted the labile mobile humic acid (MHA) and the more recalcitrant calcium humate (CaHA) fractions from soils under several long-term field experiments in the Philippines and analysed them by 15N-nuclear magnetic resonance spectroscopy. Amide N dominated the spectra of all humic acid (HA) samples (60,80% of total peak area). Its proportion of total spectral area increased with increasing intensity of cropping and length of time during which the soil was flooded and was greater in the MHA fraction than in the CaHA fraction. Simultaneously the spectral proportion of free amino N and other chemical shift regions decreased slightly with increasing length of submergence. Heterocyclic N was detected at modest proportions (7,22%) and was more prevalent in more humified samples, especially in the CaHA of aerated soils. Correlations of spectral proportions of heterocyclic N with other properties of the HA, reported elsewhere, were highly significant. Correlations were positive with visible light absorption (r=,0.86) and concentration of free radicals (r=,0.85), both of which are indices of humification, and negative with concentration of H (r=,,0.86), a negative index of humification. Correlations of spectral proportions of amide N with these properties were also highly significant but in each case of opposite sign to that of heterocyclic N. Proportions of heterocyclic N declined with increasing duration of submergence. The results suggest that (i) 15N-NMR can reproducibly measure some portion of heterocyclic N, (ii) formation of heterocyclic N is associated solely with gradual humification occurring over many years, and (iii) the abundant phenols in the submerged rice soils did not promote formation of heterocyclic N, and hence some other process is responsible for a substantial decrease in the availability of native N associated with intensive rice cropping. [source]

Fine root dynamics in a loblolly pine forest are influenced by free-air-CO2 -enrichment: a six-year-minirhizotron study

GLOBAL CHANGE BIOLOGY, Issue 3 2008
SETH G. PRITCHARD
Abstract Efforts to characterize carbon (C) cycling among atmosphere, forest canopy, and soil C pools are hindered by poorly quantified fine root dynamics. We characterized the influence of free-air-CO2 -enrichment (ambient +200 ppm) on fine roots for a period of 6 years (Autumn 1998 through Autumn 2004) in an 18-year-old loblolly pine (Pinus taeda) plantation near Durham, NC, USA using minirhizotrons. Root production and mortality were synchronous processes that peaked most years during spring and early summer. Seasonality of fine root production and mortality was not influenced by atmospheric CO2 availability. Averaged over all 6 years of the study, CO2 enrichment increased average fine root standing crop (+23%), annual root length production (+25%), and annual root length mortality (+36%). Larger increase in mortality compared with production with CO2 enrichment is explained by shorter average fine root lifespans in elevated plots (500 days) compared with controls (574 days). The effects of CO2 -enrichment on fine root proliferation tended to shift from shallow (0,15 cm) to deeper soil depths (15,30) with increasing duration of the study. Diameters of fine roots were initially increased by CO2 -enrichment but this effect diminished over time. Averaged over 6 years, annual fine root NPP was estimated to be 163 g dw m,2 yr,1 in CO2 -enriched plots and 130 g dw m,2 yr,1 in control plots (P= 0.13) corresponding to an average annual additional input of fine root biomass to soil of 33 g m,2 yr,1 in CO2 -enriched plots. A lack of consistent CO2× year effects suggest that the positive effects of CO2 enrichment on fine root growth persisted 6 years following minirhizotron tube installation (8 years following initiation of the CO2 fumigation). Although CO2 -enrichment contributed to extra flow of C into soil in this experiment, the magnitude of the effect was small suggesting only modest potential for fine root processes to directly contribute to soil C storage in south-eastern pine forests. [source]

Seasonal changes in the effects of elevated CO2 on rice at three levels of nitrogen supply: a free air CO2 enrichment (FACE) experiment

GLOBAL CHANGE BIOLOGY, Issue 6 2003
HAN-YONG KIM
Abstract Over time, the stimulative effect of elevated CO2 on the photosynthesis of rice crops is likely to be reduced with increasing duration of CO2 exposure, but the resultant effects on crop productivity remain unclear. To investigate seasonal changes in the effect of elevated CO2 on the growth of rice (Oryza sativa L.) crops, a free air CO2 enrichment (FACE) experiment was conducted at Shizukuishi, Iwate, Japan in 1998,2000. The target CO2 concentration of the FACE plots was 200 µmol mol,1 above that of ambient. Three levels of nitrogen (N) were supplied: low (LN, 4 g N m,2), medium [MN, 8 (1998) and 9 (1999, 2000) g N m,2] and high N (HN, 12 and 15 g N m,2). For MN and HN but not for LN, elevated CO2 increased tiller number at panicle initiation (PI) but this positive response decreased with crop development. As a result, the response of green leaf area index (GLAI) to elevated CO2 greatly varied with development, showing positive responses during vegetative stages and negative responses after PI. Elevated CO2 decreased leaf N concentration over the season, except during early stage of development. For MN crops, total biomass increased with elevated CO2, but the response declined linearly with development, with average increases of 32, 28, 21, 15 and 12% at tillering, PI, anthesis, mid-ripening and grain maturity, respectively. This decline is likely to be due to decreases in the positive effects of elevated CO2 on canopy photosynthesis because of reductions in both GLAI and leaf N. Up to PI, LN-crops tended to have a lower response to elevated CO2 than MN- and HN-crops, though by final harvest the total biomass response was similar for all N levels. For MN- and HN-crops, the positive response of grain yield (ca. 15%) to elevated CO2 was slightly greater than the response of final total biomass while for LN-crops it was less. We conclude that most of the seasonal changes in crop response to elevated CO2 are directly or indirectly associated with N uptake. [source]

Oral contraceptive use, hormone replacement therapy, reproductive history and risk of colorectal cancer in women

INTERNATIONAL JOURNAL OF CANCER, Issue 3 2008
Geoffrey C. Kabat
Abstract Evidence from epidemiologic studies suggests a possible role of exogenous and endogenous hormones in colorectal carcinogenesis in women. However, with respect to exogenous hormones, in contrast to hormone replacement therapy, few cohort studies have examined oral contraceptive use in relation to colorectal cancer risk. We used data from a large cohort study of Canadian women enrolled in a randomized controlled trial of breast cancer screening to assess the association of oral contraceptive use, hormone replacement therapy and reproductive factors with risk of colorectal cancer, overall and by subsite within the colorectum. Cancer incidence and mortality were ascertained by linkage to national databases. Among 89,835 women aged 40,59 at enrollment and followed for an average of 16.4 years, we identified 1,142 incident colorectal cancer cases. Proportional hazards models were used to estimate the associations between the exposures of interest and risk of colorectal cancer. Ever use of oral contraceptives at baseline was associated with a modest reduction in the risk of colorectal cancer (hazard ratio 0.83, 95% confidence interval 0.73,0.94), with similar effects for different subsites within the colorectum. No trend was seen in the hazard ratios with increasing duration of oral contraceptive use. No associations were seen with use of hormone replacement therapy (ever use or duration of use) or reproductive factors. Our results are suggestive of an inverse association between oral contraceptive use and colorectal carcinogenesis. However, given the lack of a dose,response relationship and the potential for confounding, studies with more complete assessment of exogenous hormone use throughout the life course are needed to clarify this association. © 2007 Wiley-Liss, Inc. [source]

Comparison of risk factors for invasive squamous cell carcinoma and adenocarcinoma of the cervix: Collaborative reanalysis of individual data on 8,097 women with squamous cell carcinoma and 1,374 women with adenocarcinoma from 12 epidemiological studies

INTERNATIONAL JOURNAL OF CANCER, Issue 4 2007
Article first published online: 27 NOV 200
Abstract Squamous cell carcinomas account for about 80% of cancers of the uterine cervix, and the majority of the remainder are adenocarcinomas. There is limited evidence on the extent to which these histological types share a common etiology. The International Collaboration of Epidemiological Studies of Cervical Cancer has brought together and combined individual data on 8,097 women with invasive squamous cell carcinoma, 1,374 women with invasive adenocarcinoma and 26,445 women without cervical cancer (controls) from 12 epidemiological studies. Compared to controls, the relative risk of each histological type of invasive cervical cancer was increased with increasing number of sexual partners, younger age at first intercourse, increasing parity, younger age at first full-term pregnancy and increasing duration of oral contraceptive use. Current smoking was associated with a significantly increased risk of squamous cell carcinoma (RR = 1.50, 95% CI: 1.35,1.66) but not of adenocarcinoma (RR = 0.86 (0.70,1.05)), and the difference between the two histological types was statistically significant (case-case comparison p < 0.001). A history of screening (assessed as having had at least one previous nondiagnostic cervical smear) was associated with a reduced risk of both histological types, but the reduction was significantly greater for squamous cell carcinoma than for adenocarcinoma (RR = 0.46 (0.42,0.50) and 0.68 (0.56,0.82), respectively; case,case comparison, p = 0.002). A positive test for cervical high-risk HPV-DNA was a strong risk factor for each histological type, with 74% of squamous cell carcinomas and 78% of adenocarcinomas testing positive for HPV types 16 or 18. Squamous cell and adenocarcinoma of the cervix share most risk factors, with the exception of smoking. © 2006 Wiley-Liss, Inc. [source]

Treatment of cartilage with ,-aminopropionitrile accelerates subsequent collagen maturation and modulates integrative repair

JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 3 2005
Kevin B. McGowan
Abstract Integrative repair of cartilage was previously found to depend on collagen synthesis and maturation. ,-aminopropionitrile (BAPN) treatment, which irreversibly blocks lysyl oxidase, inhibited the formation of collagen crosslinks, prevented development of adhesive strength, and caused a buildup of GuHCl-extractable collagen crosslink precursors. This buildup of crosslink precursor in the tissue may be useful for enhancing integrative repair. We tested in vitro the hypothesis that pre-treatment of cartilage with BAPN, followed by washout before implantation, could be a useful therapeutic strategy to accelerate subsequent collagen maturation. In individual cartilage disks, collagen processing was reversibly blocked by BAPN treatment (0.1 mM) as indicated by a BAPN-induced increase in the total and proportion of incorporated radiolabel that was extractable by 4 M guanidine-HCl, followed by a decrease, within 3,4 days of BAPN washout, in the proportion of extractable radiolabel to control levels. With a similar pattern, integration between pairs of apposed cartilage blocks was reversibly blocked by BAPN treatment, and followed by an enhancement of integration after BAPN washout. The low and high levels of integration were associated with enrichment in [3H]proline in a form that was susceptible and resistant, respectively, to extraction. With increasing duration up to 7 days after BAPN pre-treatment, the levels of [3H]proline extraction decreased, and the development of adhesive strength increased. Thus, BAPN can be used to modulate integrative cartilage repair. © 2004 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved. [source]

Dissociated Activity and Pulmonary Vein Fibrillation Following Functional Disconnection:

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 6 2003
Impact for the Arrhythmogenesis of Focal Atrial Fibrillation
The present study sought to investigate the electrophysiological properties of isolated pulmonary veins following successful radiofrequency (RF) catheter ablation in patients with paroxysmal atrial fibrillation (PAF). Overall, 71 pulmonary veins in 37 consecutive patients (age:56 ± 9 years) with recurrent PAF were targeted for RF ablation at the ostial region in order to achieve a complete functional block. Following disconnection, the incidence of dissociated pulmonary vein (PV) activity and its response to orciprenalin were studied. RF ablation abolished conduction in 67 (94%) of 71 potentially arrhythmogenic PVs after a mean of10.7 ± 6.4 RFapplications for each PV. After ablation, spontaneous dissociated automatic activity (9 to 52 beats/min, median 27) was found in 6 out of 67 isolated PVs (left superior:n = 1, left inferior:n = 1, right superior:n = 2, common left PV:n = 2). Slight acceleration (13 to 68 beats/min, median 29) of dissociated PV activity was observed during infusion of orciprenalin. Following isolation, initiation of sustained or nonsustained local fibrillation was recorded in only two cases of the common left sided PV with preceding automatic activity. In one patient PV fibrillation occurred during orciprenalin infusion following a repetitive response to a dissociated automatic rhythm with increasing duration as well as destabilization. In the other patient, PV fibrillation occurred immediately after the occurrence of PV automaticity. Slow dissociated automatic rhythms are detectable within 9% of disconnected PVs. The unique anatomic substrate of common left PVs seem to favor the occurrence of local fibrillation following isolation. The initiation pattern of fibrillation within the isolated PV has pathophysiological implications and underlines the contribution of multiple factors to the onset and sustenance of PAF. (PACE 2003; 26:1363,1370) [source]

Analgesia for circumcision in a paediatric population: comparison of caudal bupivacaine alone with bupivacaine plus two doses of clonidine

PEDIATRIC ANESTHESIA, Issue 6 2001
P. Sharpe FRCA
Background:,Clonidine is often used to improve the duration and quality of analgesia produced by caudal epidural blockade, although the optimum dose of clonidine with bupivacaine remains uncertain. Methods:,We compared the effect of clonidine, 1 and 2 ,g·kg,1, added to bupivacaine (1.25 mg·kg,1) with that of bupivacaine alone in 75 male children undergoing elective circumcision. Results:,There was a trend towards increasing duration of analgesia with increasing dose of clonidine [group B (bupivacaine) 280.7 (171.6) min, C1 (bupivacaine + clonidine 1 ,g·kg,1) 327.8 (188.3) min and C2 (bupivacaine + clonidine 2 ,g·kg,1) 382.0 (200.6) min], although this difference was not statistically significant. Mean time to arousal from anaesthesia was significantly prolonged with clonidine 2 ,g kg,1 (group C2 21.3 (13,36) min, group C1 14.0 (6,25) min and group B 14.4 (2,32) min. Supplementary analgesic requirements and incidence of adverse effects were low, with no differences between the groups. Conclusions:,For paediatric circumcision, under general anaesthesia, the addition of clonidine 2 ,g·kg,1 to low volume (0.5 ml·kg,1) caudal anaesthetics has a limited clinical benefit for children undergoing circumcision. [source]

Mortality patterns among workers exposed to arsenic, cadmium, and other substances in a copper smelter

AMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 8 2009
Gary M. Marsh PhD
Abstract Objective To evaluate the long-term mortality experience of workers exposed to arsenic, cadmium, and other substances at a copper mine and smelter in Copperhill, Tennessee studied earlier as part of an industry-wide study. Methods Subjects were 2,422 male workers employed three or more years in the smelter or mill between 1/1/46 until the plant strike and scale-down of operations in April 1996. Vital status was determined through 2000 for 99.4% of subjects and cause of death for 91.3% of 878 deaths. Historical exposures were estimated for lead, SO2, arsenic, cadmium, dust, and cobalt. We computed standardized mortality ratios (SMRs) based on U.S. and local county rates and modeled internal relative risks (RRs). Results We observed overall deficits in deaths based on national and local county comparisons from all causes, all cancers and most of the cause of death categories examined. We found limited evidence of increasing mortality risks from cerebrovascular disease with increasing duration and cumulative arsenic exposure, but no evidence of an exposure,response relationship for cadmium exposure and bronchitis. Conclusions Our limited evidence of an association between inhaled arsenic exposure and CVD is an exploratory finding not observed in other epidemiology studies of more highly exposed occupational populations. Possible alternative explanations include chance alone and uncontrolled confounding or effect modification by co-exposures or other factors correlated with arsenic exposure and unique to the Copperhill facility. Am. J. Ind. Med. 52:633,644, 2009. © 2009 Wiley-Liss, Inc. [source]

Effects of temperature and continuous and interrupted wetness on the infection of pear leaves by conidia of Venturia nashicola

PLANT PATHOLOGY, Issue 3 2005
B.-H. Li
Experiments were conducted to determine: (i) the effects of temperature and duration of continuous wet periods on the infection of pear seedlings by conidia of Venturia nashicola, the causal agent of pear scab; and (ii) the effects of the length and temperature of dry interrupting periods on the mortality of infecting conidia. Average number of scab lesions per leaf increased with increasing duration of wetness. Logistic models adequately described the change in the average number of scab lesions per leaf at 5, 10, 15, 20 and 25°C over the wetness duration. At 30°C, only a few lesions developed. Simple polynomial models satisfactorily described the relationship of the three logistic model parameters (maximum number of lesions, rate of appearance and the time to 50% of the maximum number of lesions) with temperature. The optimum temperature for infection was found to be approximately 20°C. The relationship between mortality and the length of a dry period interrupting an infection process can be satisfactorily described by an exponential model. The rate of mortality at 10, 16 and 22°C did not differ significantly, but was significantly less than that at 28°C. [source]

Mortality in a Swedish rubber tire manufacturing plant: Occupational risks or an "unhealthy worker" effect?

AMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 8 2006
Gun Wingren PhD
Abstract Background In this cohort study a classification of 12 work categories, with specified common exposures, is used to evaluate the mortality among workers in a Swedish rubber tire plant. Methods Mortality among the cohort members is compared with expected values from national rates. Standardized mortality ratios (SMR) were calculated for the total cohort, for sub-cohorts and with the inclusion of a latency requirement. Results Male workers had increased risks for total mortality, circulatory death, respiratory death, mental disorders, epilepsy, injuries/poisoning, and for alcohol-related death. Many risks were noted among workers exposed to dust, fumes, or vapor. No trend in risk with increasing duration of employment was seen. Discussion Some established risks for rubber workers could be related to some specified work categories. The highest risks were noted among workers having a very short duration of employment indicating a possible "unhealthy worker effect" associated with life-style factors or to tasks offered to unskilled workers. Am. J. Ind. Med. 2006. © 2006 Wiley-Liss, Inc. [source]

Delay of Adequate Empiric Antibiotic Therapy Is Associated with Increased Mortality among Solid-Organ Transplant Patients

AMERICAN JOURNAL OF TRANSPLANTATION, Issue 7 2009
B. Hamandi
Empiric antibiotic therapy is often prescribed prior to the availability of bacterial culture results. In some cases, the organism isolated may not be susceptible to initial empiric therapy (inadequate empiric therapy or IET). In solid-organ transplant recipients, the overall incidence and clinical importance of IET is unknown. We performed a retrospective cohort study of patients admitted from 2002 to 2004. Multiple logistic regression analyses were conducted to determine associations between potential determinants and mortality. IET was administered in 169/312 (54%) patients, with a hospital mortality rate that was significantly greater than those receiving adequate therapy (24.9% vs. 7.0%; relative risk [RR] 3.55; 95% confidence interval [CI], 1.85,6.83; p < 0.001). Regression analysis demonstrated that an increasing duration of IET (adjusted odds ratio [OR] at 24 h: 1.33; 95% CI: 1.15,1.53; p < 0.001), ICU-associated infections (adjusted OR: 6.27; 95% CI: 2.79,14.09; p < 0.001), prior antibiotic use (adjusted OR: 3.56; 95% CI: 1.51,8.41; p = 0.004) and increasing APACHE-II scores (adjusted OR: 1.26; 95% CI: 1.16,1.34; p < 0.001) were independently correlated with hospital mortality. IET is common and appears to be associated with an increased hospital mortality rate in the solid-organ transplant population. [source]

Effect of chronic oestrogen administration on androgen receptor expression in reproductive organs and pituitary of adult male rat

ANDROLOGIA, Issue 3 2010
M. C. Kaushik
Summary Following chronic (15 or 30 days) treatment with oestradiol 3-benzoate (75 ,g rat,1 day,1 in 100 ,l of olive oil) to adult rats, androgen receptor (AR) expression was analysed simultaneously in testis, epididymis, seminal vesicle, prostate and pituitary utilising three independent tools i.e. immunohistochemistry, Western blotting and RT-PCR. All the five organs showed higher AR transcriptional activity gradually increasing from 15 to 30 days of oestrogen treatment. However, the AR protein expression either through immunostaining or Western blotting demonstrated a significant decline in all the reproductive organs. In the pituitary, on the other hand, the decline coincided with a distinct breakdown of the AR protein into two bands with increasing duration of treatment. Serum and intra-testicular testosterone levels were found significantly lowered. Spermatogenesis was adversely affected with concurrent decrease in weights of testis and accessory sex organs. Decrease in testis weight was consistent with the reduction in the number of maturing germ cells per tubule. Despite the decrease in weight, accessory sex organs like epididymis, seminal vesicle and prostate were completely devoid of any apoptotic cells which were characterised only in testis and pituitary. Seminiferous epithelium demonstrated a marked increase in the number of germ cells undergoing apoptosis. However, the rate of cell apoptosis was much higher in the pituitary than in the testis at the end of 30 days treatment. It is therefore concluded that degradation of AR protein expression after oestrogen treatment is probably directly linked to an increase in cell apoptosis both in testis and pituitary. [source]

Optimal duration of preoperative anti-helminthic therapy for pulmonary hydatid surgery

ANZ JOURNAL OF SURGERY, Issue 5 2010
Parvaiz A. Koul
Abstract Background:, The optimal duration of preoperative anti-helminths for prevention of recurrences in pulmonary hydatidosis is unclear, although 1,3 weeks of therapy is routinely used. Methods:, Forty-five patients of pulmonary hydatid disease were randomly assigned into four groups to receive either 0, 2, 4 or 8 weeks of preoperative albendazole (ABZ) and praziquantel (PZQ). Viability of the scolices in the fluid harvested at surgery (methylene blue staining) and ability to produce peritoneal hydatids in mice (intra-peritoneal inoculation) were compared in different groups. Results:, The percentage viability of the scolices as a whole was significantly (P < 0.001) lower in the treated cysts (n= 36, mean 43.5 ± 35.69) compared with the untreated cysts (n= 8, mean 94.75 ± 7.21). The viability progressively decreased with increasing durations of chemotherapy (P < 0.001). Mean percentage viability of scolices was 88.72 ± 4.91% in patients treated for 2 weeks (n= 12), 38.09 ± 9.10% after 4 weeks (n= 11) and 8.1 ± 9.23% after 8 weeks (n= 14). Intra-peritoneal mice inoculation was positive in 90% of the cysts that received therapy for 2 weeks or less and none of the patients who received therapy for 8 weeks had a positive inoculation. Conclusions:, Preoperative combination therapy with ABZ and PZQ effects a scolicidal response which increases with the increasing duration of the preoperative chemotherapy, and a 4-week course of the combination chemotherapeutic agents seems to be the minimum required duration for ensuring scolicidal activity enough to prevent spillage-induced recurrences following pulmonary hydatidosis. [source]

Functional Impairment of Renal Organic Cation Transport in Experimental Diabetes

BASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 4 2002
Brett Grover
The experiments compared the ability of renal cortex slices from streptozotocin-induced diabetic and non-diabetic rats to accumulate the model cation, 14C-tetraethylammonium under controlled conditions. Initial experiments demonstrated a progressive decline in tetraethylammonium accumulation with increasing duration of diabetes. The maximal decrease was observed at 21 days after streptozotocin injection. Time-dependent incubations revealed that tetraethylammonium uptake from both diabetic and non-diabetic rats followed a curvilinear pattern expected of an active process. However, at steady state the diabetic-derived slices accumulated a significant 38% less tetraethylammonium versus slices from non-diabetics. Concentration-dependent incubations of tetraethylammonium (0.01,10 mM, 60 min.) demonstrated saturable transport in both diabetic and non-diabetic slices with a significantly decreased capacity of diabetic-derived slices to accumulate tetraethylammonium. Cellular respiration rates in the two groups were not different. Insulin treatment of the diabetic rats prevented the transport decline. While the causative factor of the transport impairment in diabetes is unresolved, this study documents an aspect of diabetic nephropathy that has not been previously reported but which may have important implications for renal excretion of cationic drugs and toxicants. The results also provide a mechanism for the well-documented "protection phenomenon" by which the kidneys of diabetic rats are resistant to nephrotoxicity induced by the chemotherapeutic agent cisplatin. [source]

Duration of testosterone suppression and the risk of death from prostate cancer in men treated using radiation and 6 months of hormone therapy

CANCER, Issue 8 2007
Anthony V. D'Amico MD
Abstract BACKGROUND. The authors evaluated whether the duration of androgen suppression (AS) after the completion of hormone therapy (HT) was associated with the risk of prostate cancer-specific mortality (PCSM) and all-cause mortality (ACM). METHODS. The study cohort was comprised of 220 men who received radiation therapy (RT) and 6 months of HT for prostate cancer between 1996 and 2005. The duration of AS was defined as the time to return to the baseline testosterone level after the completion of HT. Grays and Cox regression analyses were used to evaluate whether the duration of AS after the completion of HT was associated with the time to PCSM and ACM, respectively, after adjusting for known prognostic factors. RESULTS. An increasing duration of AS was associated with a decreased risk of PCSM (adjusted hazards ratio [HR], 0.89; P = .003) and ACM (HR, 0.94; P = .007). Men who had prostate cancer with Gleason scores from 8 to 10 had significantly lower cumulative incidence estimates of PCSM (P = .04) if the duration of AS plus the length of HT administration was ,2 years compared with <2 years. After a median follow-up of 6.1 years, the respective 5-year estimates were 0% and 38%. CONCLUSIONS. The duration of AS after 6 months of HT was associated with the risk of PCSM and ACM. This duration could be used to identify men who have prostate cancer with Gleason scores from 8 to 10 in whom 6 months of HT produces long-term testosterone suppression, which may provide the cancer-specific survival benefit observed with long-term HT. Cancer 2007. © 2007 American Cancer Society. [source]

Diabetic macular oedema and visual loss: relationship to location, severity and duration

ACTA OPHTHALMOLOGICA, Issue 7 2009
Thomas W. Gardner
Abstract. Purpose:, To assess the relationship between visual acuity (VA) and diabetic macular oedema (DMO) in relation to the location of retinal thickening and the severity and duration of central macular thickening. Methods:, Data from 584 eyes in 340 placebo-treated patients in the 3-years-long Protein Kinase C Diabetic Retinopathy Study (PKC-DRS2) trial were used to investigate the relationship between VA and DMO. Eligible eyes had moderately severe to very severe non-proliferative diabetic retinopathy and VA of at least 45 letters on Early Treatment Diabetic Retinopathy Study (ETDRS) charts (Snellen equivalent = 20/125). Diabetic retinopathy and DMO status were assessed using stereo photographs. Results:, Nearly one third of study eyes had foveal centre-involving DMO at the start of the trial. Sustained moderate visual loss was found in 36 eyes, most commonly associated with DMO at the centre of the fovea in 73% of eyes. There was a strong relationship (p < 0.001) between foveal centre involvement with DMO and mean VA. Mean VA decreased with increasing retinal thickness at the centre (p < 0.001) and increasing duration of centre-involving DMO (p < 0.001). Conclusion:, This study documents the relationship between duration of DMO and progressive vision loss, and the key role of central foveal involvement in patients with diabetic retinopathy. These data will help to develop future strategies to prevent vision loss. [source]

Clinical Predictors of Occult Pneumonia in the Febrile Child

ACADEMIC EMERGENCY MEDICINE, Issue 3 2007
Charles G. Murphy MD
Background: The utility of chest radiographs (CXRs) for detecting occult pneumonia (OP) among pediatric patients without lower respiratory tract signs has been previously studied, but no predictors other than white blood cell count (WBC) and height of fever have been investigated. Objectives: To identify predictors of OP in pediatric patients in the postconjugate pneumococcal vaccination era. Methods: This was a retrospective cross sectional study that was conducted in a large urban pediatric hospital. Physician records of emergency department (ED) patients of age 10 years or less who presented with fever (,38°C) and had a CXR obtained for suspected pneumonia were reviewed. Patients were classified into two groups: "signs of pneumonia" and "no signs of pneumonia" on the basis of the presence or absence of respiratory distress, tachypnea, or lower respiratory tract findings. Occult pneumonia was defined as radiographic pneumonia in a patient without signs of pneumonia. Results: Two thousand one hundred twenty-eight patients were studied. Among patients categorized as having no signs of pneumonia (n = 1,084), 5.3% (95% CI = 4.0% to 6.8%) had OP. Presence of cough and longer duration of cough (greater than 10 days) had positive likelihood ratios (LR+) of 1.24 (95% CI = 1.15 to 1.33) and 2.25 (95% CI = 1.21 to 4.20), respectively. Absence of cough had a negative likelihood ratio (LR,) of 0.19 (95% CI = 0.05 to 0.75). The likelihood of OP increased with increasing duration of fever (LR+ for more than three days and more than five days of fever, respectively: 1.62; 95% CI = 1.13 to 2.31 and 2.24; 95% CI = 1.35 to 3.71). When obtained (56% of patients), WBC was a predictor of OP, with a LR+ of 1.76 (95% CI = 1.40 to 2.22) and 2.17 (95% CI = 1.58 to 2.96) for WBC of >15,000/mm3 and >20,000/mm3, respectively. Conclusions: Occult pneumonia was found in 5.3% of patients with fever and no lower respiratory tract findings, tachypnea, or respiratory distress. There is limited utility in obtaining a CXR in febrile children without cough. The likelihood of pneumonia increased with longer duration of cough or fever or in the presence of leukocytosis. [source]

Dimensional analysis of the earthquake-induced pounding between adjacent structures

EARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 7 2009
Elias Dimitrakopoulos
Abstract In this paper the dynamic response of two and three pounding oscillators subjected to pulse-type excitations is revisited with dimensional analysis. Using Buckingham's ,-theorem the number of variables that govern the response of the system is reduced by three. When the response is presented in the dimensionless ,-terms remarkable order emerges. It is shown that regardless of the acceleration level and duration of the pulse all response spectra become self-similar and follow a single master curve. This is true despite the realization of finite duration contacts with increasing durations as the excitation level increases. All physically realizable contacts (impacts, continuous contacts, and detachments) are captured via a linear complementarity approach. The study confirms the existence of three spectral regions. The response of the most flexible among the two oscillators amplifies in the low range of the frequency spectrum (flexible structures); whereas, the response of the most stiff among the two oscillators amplifies at the upper range of the frequency spectrum (stiff structures). Most importantly, the study shows that pounding structures such as colliding buildings or interacting bridge segments may be most vulnerable for excitations with frequencies very different from their natural eigenfrequencies. Finally, by applying the concept of intermediate asymptotics, the study unveils that the dimensionless response of two pounding oscillators follows a scaling law with respect to the mass ratio, or in mathematical terms, that the response exhibits an incomplete self-similarity or self-similarity of the second kind with respect to the mass ratio. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Optimal duration of preoperative anti-helminthic therapy for pulmonary hydatid surgery

Commonsense beliefs and the identification of familiar voices

APPLIED COGNITIVE PSYCHOLOGY, Issue 3 2001
A. Daniel Yarmey
Two experiments are reported in which participants attempted to reject the tape-recorded voice of a stranger and identify by name the voices of three personal associates who differed in their level of familiarity. In Experiment 1 listeners were asked to identify speakers as soon as possible, but were not allowed to change their responses once made. In Experiment 2 listeners were permitted to change their responses over successive presentations of increasing durations of voice segments. Also, in Experiment 2 half of the listeners attempted to identify speakers who spoke in normal-tone voices, and the remainder attempted to identify the same speakers who spoke in whispers. Separate groups of undergraduate students attempted to predict the performance of the listeners in both experiments. Accuracy of performance depended on the familiarity of speakers and tone of speech. A between-subjects analysis of rated confidence was diagnostic of accuracy for high familiar and low familiar speakers (Experiment 1), and for moderate familiar and unfamiliar normal-tone speakers (Experiment 2). A modified between-subjects analysis assessed across the four levels of familiarity yielded reliable accuracy-confidence correlations in both experiments. Beliefs about the accuracy of voice identification were inflated relative to the significantly lower actual performance for most of the normal-tone and whispered-speech conditions. Forensic significance and generalizations are addressed. Copyright © 2001 John Wiley & Sons, Ltd. [source]