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Physiological Factors (physiological + factor)
Selected AbstractsEnvironmental carcinogens and p53 tumor-suppressor gene interactions in a transgenic mouse model for mammary carcinogenesisENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 2-3 2002Daniel Medina Abstract Mouse mammary tumorigenesis is greatly influenced by a variety of exogenous agents, such as MMTV, chemical carcinogens (i.e., polycyclic aromatic hydrocarbons), and radiation, as well as by endogenous/physiological factors, such as steroid hormones, tumor-suppressor genes (i.e., Brca1/2,p53), and gene products of modifier genes. In the mouse model, the most frequently used chemical carcinogen has been 7,12-dimethylbenz[a]anthracene (DMBA), which activates the Ha- ras gene but does not alter the p53 tumor-suppressor gene. However, on an existing background of p53 gene alteration, low doses of DMBA are strongly cocarcinogenic. Using a transgenic model system, in which the p53 gene was deleted in the mammary gland, we examined the carcinogenic effects of a variety of external agents and internal factors given at either low doses or physiological doses. These agents/factors included DMBA, ,-radiation, Brca2 heterozygosity, and steroid hormones. All agents/factors increased the tumorigenic response of the p53 null mammary cells, even under conditions where no tumorigenic response was observed in the p53 wildtype mammary cell. The strongest cocarcinogenic effect was observed with the steroid hormone progesterone. The majority of tumors were highly aneuploid and composed of nuclear igh-grade cells. The mechanism for the aneuploidy and secondary events associated with high tumorigenicity were examined using array technology. These results demonstrate that, on a background of underlying genetic instability, very low doses of environmental mutagens and mitogens can produce strong cocarcinogenic effects. Environ. Mol. Mutagen. 39:178,183, 2002. © 2002 Wiley-Liss, Inc. [source] Individual difference in the number of chewing strokes and its determinant factorsJOURNAL OF ORAL REHABILITATION, Issue 2 2006T. UEDA summary, This study was carried out to clarify the distribution and individual variation of the number of chewing strokes before last swallowing (NCS), as well as to assess the factors that affect NCS, when dentulous adults masticate the same type of food. NCS was measured in 75 dentulous adults using gummy candies. Measurements were repeated five times to obtain the average and variation. Moreover, the correlation of NCS with various physiological factors (lateral width and vertical distance of chewing loop, angle of opening and closing path, opening and closing time, occlusal time, masticatory performance, number of occlusal contact points, occlusal contact area, occlusal force, flow rate of whole saliva and viscosity of whole saliva) and 28 personality factors were analysed by both of the single variate analysis and the multivariate analysis. The results showed that the average NCS was 41·0 ± 16·0, and the coefficient of variation was 0·090 ± 0·040. Additionally, the correlation between NCS and each factor was investigated, and found that any of these factors did not function as a single determinant for NCS. Following, determinant factors were further examined by the stepwise method of linear multiple regression analysis. From these analysis we found that when opening and closing time and four personality factors were combined, they were significantly involved in determining NCS (P < 0·01). Therefore, we conclude that individual NCS until last swallowing is not determined by a sole, specific physiological factor but is affected by multiple factors including personality. [source] Sensory, clinical and physiological factors in sensitive skin: a reviewCONTACT DERMATITIS, Issue 1 2006Miranda A. Farage Certain individuals experience more intense and frequent adverse sensory effects than the normal population after topical use of personal care products, a phenomenon known in popular usage as sensitive skin. Consumer reports of sensitive skin are self-diagnosed and often not verifiable by objective signs of physical irritation. Companies who manufacture cosmetic and personal care products are challenged to provide safe products to an audience with tremendous differences in skin type, culture and habits. This review examines the still incomplete understanding of this phenomenon with respect to aetiology, diagnosis, appropriate testing methods, possible contributing host factors such as, sex, ethnicity, age, anatomical site, cultural and environmental factors, and the future directions needed for research. [source] Heart rate variation and electroencephalograph , the potential physiological factors for thermal comfort studyINDOOR AIR, Issue 2 2009Y. Yao First page of article [source] Host reproduction and a sexually transmitted disease: causes and consequences of Coccipolipus hippodamiae distribution on coccinellid beetlesJOURNAL OF ANIMAL ECOLOGY, Issue 1 2004K. Mary Webberley Summary 1We know that sexually transmitted parasites and pathogens have extremely deleterious effects in human and domesticated animal populations, but know little of sexually transmitted diseases (STDs) in natural populations. 2One previously reported natural system is the sexually transmitted mite, Coccipolipus hippodamiae, on the eastern European coccinellid, Adalia bipunctata. Our aims were to determine how widespread this parasite is in terms of incidence and prevalence across host species, to identify the causes of the prevalence pattern and whether the parasite reduces fertility in all host species. 3Coccipolipus hippodamiae was present on four of 19 European species examined. The wide distribution and high prevalence of C. hippodamiae on A. bipunctata indicates that this is the major host. The mite was also present at substantial prevalence on Adalia decempunctata and at lower prevalence on Synharmonia (=Oenopia) conglobata and Calvia quatuordecimguttata. 4Laboratory studies on mite development time and transmission efficiency revealed that although physiological factors may affect incidence, they do not explain prevalence variation between hosts, but characteristics of host life history and reproductive behaviour are important in this context. Adalia bipunctata is more promiscuous than the less commonly infected A. decempunctata and S. conglobata. Diapause is needed before breeding will occur in C. quatuordecimguttata, leading to a lack of the consistent sexual activity between generations, which is needed for STD maintenance. Calvia quatuordecimguttata is probably periodically reinfected through hybrid matings with other host species. 5Coccipolipus hippodamiae infection has similar strong deleterious effects on female reproduction in A. decempunctata and S. conglobata as have previously been demonstrated in A. bipunctata. 6The results indicate that STDs may play a profound role in the ecology of promiscuous insect populations with overlapping generations. Here they may reach significant prevalence whilst exhibiting extreme virulence. [source] Paradigm Shift for the Alcohol Breath TestJOURNAL OF FORENSIC SCIENCES, Issue 2 2010Michael P. Hlastala Ph.D. Abstract:, The alcohol breath test (ABT) has been used for quantification of ethyl alcohol in individuals suspected of driving under the influence for more than 50 years. In this time, there has been little change in the concepts underlying this single breath test. The old model, which assumes that end-exhaled breath alcohol concentration is closely related to alveolar air alcohol concentration, is no longer acceptable. This paper reviews experimental research and mathematical modeling which has evaluated the pulmonary exchange processes for ethyl alcohol. Studies have shown that alcohol exchanges dynamically with the airway tissue both during inspiration and expiration. The airway tissue interaction makes it impossible to deliver air with alveolar alcohol concentration to the mouth. It is concluded that the ABT is dependent on physiological factors that need to be assessed for accurate testing. [source] Identifying facilitators and barriers to physical activity for adults with Down syndromeJOURNAL OF INTELLECTUAL DISABILITY RESEARCH, Issue 9 2010J. Mahy Abstract Background Adults with Down syndrome are typically sedentary, and many do not participate in the recommended levels of physical activity per week. The aim of this study was to identify the facilitators and barriers to physical activity for this group. Method Semi-structured interviews were conducted to elicit the views of adults with Down syndrome and their support people about what factors facilitate physical activity and what factors are barriers to activity. A sample of 18 participants (3 men, 15 women) was recruited through two agencies providing services for adults with disabilities; six participants were adults with Down syndrome and 12 participants were support people (four were parents of adults with Down syndrome and eight participants were employed by day programmes attended by the adults with Down syndrome). The interviews were recorded, transcribed verbatim and independently coded by two researchers. Results Three themes around facilitators to physical activity were identified: (1) support from others; (2) that the physical activity was fun or had an interesting purpose; and (3) routine and familiarity. Three themes around barriers were also identified: (1) lack of support; (2) not wanting to engage in physical activity; and (3) medical and physiological factors. Conclusions The results suggest that support people play a key role, both as facilitators and barriers, in the participation by adults with Down syndrome in physical activity. Many of the barriers and facilitators of activity for adults with Down syndrome indentified are similar to those reported for adults without impairment. Our findings are also consistent with established theories in the field of health behaviour change. [source] Chronological analysis of physiological T2* signal change in the cerebrum during breath holdingJOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 3 2001Kazuyoshi Nakada MD Abstract The purpose of this study was to examine which physiological factors affect cerebral T2* signal intensity (SI) during breath holding (BH) (apnea after inspiration and breathing after expiration) in normal volunteers. We examined SI changes caused by anoxic gas inhalation, by respiratory movements, and by BH. High-speed echo planar images (EPI) showed changes in SI that could be divided into five phases. Reports indicate that SI changes induced by BH are due to the effects on the magnetic susceptibility of deoxygenated hemoglobin (deoxyhemoglobin (dHb)) and to hypercapnia, but these reports could not fully explain the observed five phases. In addition to deoxyhemoglobin susceptibility and hypercapnia, we found that respiratory movements play a third critical role in modifying SI by affecting blood flow into the region of interest (ROI), as judged from right carotid artery flow. Consequently, we propose that the physiological SI changes induced by BH are derived from blood oxygenation, hypercapnia, and respiratory movements. J. Magn. Reson. Imaging 2001;13:344,351. © 2001 Wiley-Liss, Inc. [source] Individual difference in the number of chewing strokes and its determinant factorsJOURNAL OF ORAL REHABILITATION, Issue 2 2006T. UEDA summary, This study was carried out to clarify the distribution and individual variation of the number of chewing strokes before last swallowing (NCS), as well as to assess the factors that affect NCS, when dentulous adults masticate the same type of food. NCS was measured in 75 dentulous adults using gummy candies. Measurements were repeated five times to obtain the average and variation. Moreover, the correlation of NCS with various physiological factors (lateral width and vertical distance of chewing loop, angle of opening and closing path, opening and closing time, occlusal time, masticatory performance, number of occlusal contact points, occlusal contact area, occlusal force, flow rate of whole saliva and viscosity of whole saliva) and 28 personality factors were analysed by both of the single variate analysis and the multivariate analysis. The results showed that the average NCS was 41·0 ± 16·0, and the coefficient of variation was 0·090 ± 0·040. Additionally, the correlation between NCS and each factor was investigated, and found that any of these factors did not function as a single determinant for NCS. Following, determinant factors were further examined by the stepwise method of linear multiple regression analysis. From these analysis we found that when opening and closing time and four personality factors were combined, they were significantly involved in determining NCS (P < 0·01). Therefore, we conclude that individual NCS until last swallowing is not determined by a sole, specific physiological factor but is affected by multiple factors including personality. [source] Egg mass and incubation period allometry in birds and reptiles: effects of phylogenyJOURNAL OF ZOOLOGY, Issue 2 2006D. C. Deeming Abstract Here we test the hypothesis that the relationship between egg mass at oviposition (IEM) and incubation period (Ip) is a function of the taxonomic relatedness of bird and reptile species. Allometric relationships between IEM and Ip were examined for 1525 bird species and 201 reptilian species. Treating species as independent data revealed the allometric exponent linking Ip to IEM to be 0.234 for birds and 0.138 for reptiles. However, ANCOVA revealed that within both birds and reptiles the elevation and slope of the regression lines were dependent on the taxonomic order studied, indicating that the exponents were confounded by the phylogenetic relatedness of species. Thus, allometric exponents were recalculated based on the method of comparative analysis using independent contrasts. This technique revealed that the allometric exponent in both birds and reptiles was confounded by phylogeny. In birds the allometric relationship between Ip and IEM was almost halved to 0.122, whereas in reptiles the exponent increased to 0.185. Importantly, the results demonstrate that some results of allometric analyses can be artefacts of the method of analysis of the dataset. That for bird eggs Ip is not determined in large part by egg mass allows new questions to be posed regarding the ecological and physiological factors affecting the length of incubation, and hence rates of embryonic growth, for different taxa and habitats. [source] Biosynthesis profile and endogenous titers of polyamines differ in totipotent and recalcitrant plant protoplastsPHYSIOLOGIA PLANTARUM, Issue 1 2005Anastasia K. Papadakis The expression of totipotency in plant protoplasts is a complex developmental phenomenon and is affected by genetic and physiological factors. Polyamines (PAs) are known to be involved in a variety of growth and developmental processes in higher plants, as well as in adaptation to stresses. In this study, we present the homeostatic characteristics of the endogenous PA putrescine (Put), spermidine (Spd), and spermine (Spm) in totipotent (T) and non-totipotent (NT) tobacco protoplasts and in recalcitrant (R) grapevine protoplasts. T-tobacco protoplasts, with high division rates, have the highest level of endogenous PAs. In these protoplasts, the soluble-hydrolyzed fraction predominates and increases, and the insoluble-hydrolyzed fraction also increases, whereas soluble (S) PAs decrease rapidly during culture. The isolation process contributes to the increased Put levels, which are higher in freshly isolated NT-tobacco protoplasts than in T-protoplasts. During culture, total Put predominates over Spd and Spm, and the highest accumulation is found in T-protoplasts. Ornithine decarboxylase and arginase activities both increase in T-protoplasts, whereas arginine decarboxylase activity causes Put accumulation in NT-tobacco protoplasts. R-grapevine protoplasts show a different PA profile, mostly due to the lower PA content, the higher S-fraction, and the higher ratio of Spm to total PAs. The data suggest that the levels and metabolism of the intracellular PAs could be related to the expression of totipotency of plant protoplasts. [source] Ecophysiological and morphological parameters related to survival in grass species exposed to an extreme climatic eventPHYSIOLOGIA PLANTARUM, Issue 4 2005Ann Milbau An experiment was performed to elucidate interspecific differences in survival time of grass species subjected to an extreme climatic event. We exposed eight grass species to a simulated heat wave in the field (,free air' temperature increase at 11°C above ambient) combined with drought. We determined whether interspecific differences in survival time were related to the responses of the species to the imposed stress or could be explained by their ecophysiological or morphological characteristics in unstressed conditions. Surprisingly, there was no effect of specific leaf area, but species with a higher total leaf area survived longer. This may arise from a greater water reserve in the plant as a whole, which could delay the desiccation of the meristem, or from reduced evaporation due to a higher leaf area index. Species in which the decrease in light-saturated stomatal conductance (gs) and photosynthetic CO2 uptake rate (Amax) was strongly related to the decrease in soil water availability (measured as soil relative water content and stress duration) survived longer than species in which gs and Amax likewise declined but responded more to daily fluctuations in irradiance, temperature, and vapor pressure deficit during the heat wave. We, therefore, hypothesize that interspecific differences in stress survival time might be related to the extent to which stomata react to changes in soil water conditions relatively to changes in other environmental and physiological factors. The results suggest that resistance to extremes is governed by other mechanisms than resistance to moderate drought. [source] Optimization of Agrobacterium -mediated transient assays of gene expression in lettuce, tomato and ArabidopsisPLANT BIOTECHNOLOGY JOURNAL, Issue 2 2005Tadeusz Wroblewski Summary Agrobacterium -mediated transient assays for gene function are increasingly being used as alternatives to genetic complementation and stable transformation. However, such assays are variable and not equally successful in different plant species. We analysed a range of genetic and physiological factors affecting transient expression following agroinfiltration, and developed a protocol for efficient and routine transient assays in several plant species. Lettuce exhibited high levels of transient expression and was at least as easy to work with as Nicotiana benthamiana. Transient expression occurred in the majority of cells within the infiltrated tissue and approached 100% in some regions. High levels of transient expression were obtained in some ecotypes of Arabidopsis; however, Arabidopsis remains recalcitrant to routine, genotype-independent transient assays. Transient expression levels often exceeded those observed in stably transformed plants. The laboratory Agrobacterium tumefaciens strain C58C1 was the best strain for use in plant species that did not elicit a necrotic response to A. tumefaciens. A wild A. tumefaciens strain, 1D1246, was identified that provided high levels of transient expression in solanaceous plants without background necrosis, enabling routine transient assays in these species. [source] Evaporative enrichment and time lags between ,18O of leaf water and organic pools in a pine standPLANT CELL & ENVIRONMENT, Issue 5 2007ROMAIN L. BARNARD ABSTRACT Understanding ecosystem water fluxes has gained increasing attention, as climate scenarios predict a drier environment for many parts of the world. Evaporative enrichment of 18O (,18O) of leaf water and subsequent enrichment of plant organic matter can be used to characterize environmental and physiological factors that control evaporation, based on a recently established mechanistic model. In a Pinus sylvestris forest, we measured the dynamics of oxygen isotopic composition (,18O) every 6 h for 4 d in atmospheric water vapour, xylem sap, leaf water and water-soluble organic matter in current (N) and previous year (N-1) needles, phloem sap, together with leaf gas exchange for pooled N and N-1 needles, and relevant micrometeorological variables. Leaf water ,18O showed strong diel periodicity, while ,18O in atmospheric water vapour and in xylem sap showed little variation. The ,18O was consistently lower for N than for N-1 needles, possibly related to phenological stage. Modelled leaf water ,18O showed good agreement with measured values when applying a non-steady state evaporative enrichment model including a Péclet effect. We determined the time lags between ,18O signals from leaf water to water-soluble foliar organic matter and to phloem sap at different locations down the trunk, which clearly demonstrated the relevance of considering these time-lag effects for carbon transport, source-sink and carbon flux partitioning studies. [source] Assessing environmental and physiological controls over water relations in a Scots pine (Pinus sylvestris L.) stand through analyses of stable isotope composition of water and organic matterPLANT CELL & ENVIRONMENT, Issue 1 2007ELKE BRANDES ABSTRACT This study investigated the influence of meteorological, pedospheric and physiological factors on the water relations of Scots pine, as characterized by the origin of water taken up, by xylem transport as well as by carbon isotope discrimination (,13C) and oxygen isotope enrichment (,18O) of newly assimilated organic matter. For more than 1 year, we quantified ,2H and ,18O of potential water sources and xylem water as well as ,13C and ,18O in twig and trunk phloem organic matter biweekly, and related these values to continuously measured or modelled meteorological parameters, soil water content, stand transpiration (ST) and canopy stomatal conductance (Gs). During the growing season, ,18O and ,2H of xylem water were generally in a range comparable to soil water from a depth of 2,20 cm. Long residence time of water in the tracheids uncoupled the isotopic signals of xylem and soil water in winter. ,18O but not ,13C in phloem organic matter was directly indicative of recent environmental conditions during the whole year. ,18O could be described applying a model that included 18O fractionation associated with water exchange between leaf and atmosphere, and with the production of organic matter as well as the influence of transpiration. Phloem ,13C was assumed to be concertedly influenced by Gs and photosynthetically active radiation (PAR) (as a proxy for photosynthetic capacity). We conclude that isotope signatures can be used as effective tools (1) to characterize the seasonal dynamics in source and xylem water, and (2) to assess environmental effects on transpiration and Gs of Scots pine, thus helping to understand and predict potential impacts of climate change on trees and forest ecosystems. [source] Composite estimates of physiological stress, age, and diabetes in American SamoansAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 3 2007Douglas E. Crews Abstract Composite estimates of physiological stress such as allostatic load (AL) were developed to help assess cumulative impacts of psychosocial and physical stressors on the body. Physiological responses to stress generally accelerate somatic wear-and-tear and chronic degenerative conditions (CDCs). Following McEwen (Neuropsychopharmacology 22 (1999) 108,124) and others, primary physiological mediators of somatic stress responses include glucocorticoids (cortisol), catecholamines (adrenaline and noradrenaline), and serum dihydroepiandosterone-sulfate (DHEA-S). Conversely, blood pressure (BP), serum HDL and total cholesterol, glycated hemoglobin (HbA1c), and waist/hip (w/h) ratio are modulated by such hormones, thereby acting as secondary mediators of stress response. When these risk factors are aggregated into a composite score, higher stress loads are associated with increased risks for days of school/work missed, functional losses, morbidity, and mortality in US samples. To examine stress loads in American Samoans, data on all 6 secondary mediators along with estimates of body habitus (i.e. height, weight, circumferences, skinfolds) and physiology (i.e. fasting insulin, LDLc, triglycerides, fasting glucose) were measured on 273 individuals residing on Tutuila Island in 1992. Four combinations of these physiological factors were used to determine composite estimates of stress. These were then assessed by sex for associations with age and the presence of diabetes. Composite estimates of stress load were higher in Samoan women than men. Associations with age tended to be low and negative in men, but positive in women, appearing to reflect cultural circumstances and population history. Stress load scores also were higher among those with diabetes than those without among both men and women. These results suggest that composite estimates of stress may be useful for assessing future risks of CDC's and the senescent processes that may underlie them in cross-cultural research. Am J Phys Anthropol, 2007. © 2007 Wiley-Liss, Inc. [source] Fatigue and associated factors in hemodialysis patients in TaiwanRESEARCH IN NURSING & HEALTH, Issue 1 2006H.E. Liu Abstract The number of patients suffering from end-stage renal disease is increasing rapidly around the world, including in Taiwan. Hemodialysis (HD) patients report fatigue as a major stressor. The purpose of this correlational study with systematic sampling was to explore fatigue and associated physiological, psychological, and situational factors in 119 Taiwanese HD patients. Results indicate that levels of fatigue were mild. Three variables (gender, employment, and depression) had a significant impact on fatigue. Some differences in physiological factors by depression, gender, and employment were found. Stepwise regressions showed that depression, age, and urea reduction ratio were significant predictors for overall fatigue and two of its dimensions. Some relationships from the theory of unpleasant symptoms were supported. © 2006 Wiley Periodicals, Inc. Res Nurs Health 29:40,50, 2006 [source] Sources of variation in fecal cortisol levels in howler monkeys in belizeAMERICAN JOURNAL OF PRIMATOLOGY, Issue 7 2010Alison M. Behie Abstract High cortisol levels are known to cause low fecundity and increased mortality; thus, the prospect of using cortisol as a measure of population health is an exciting one. However, because so many factors can interact to influence cortisol release, it can be difficult to interpret what exactly is creating changes to cortisol levels. This study investigates variation in fecal cortisol levels in a population of black howlers (Alouatta pigra) from 350 fecal samples collected from 33 individuals in more than 4 years. A general linear mixed model revealed that cortisol varied significantly with fruit availability and contact with tourists. When fruit availability was low, cortisol increased, likely because when fruit availability is low monkeys eat less fruit, thus obtaining less sugar. This result may simply reflect cortisol's metabolic function of mobilizing glucose. It also indicates that these monkeys may be experiencing periods of food stress throughout the year, which was earlier thought to be minimal for a primarily folivorous species. Presence of tourists was the only other factor found to lead to high cortisol; with exposure to tourists increasing stress levels. These results highlight the importance of understanding how physiological factors can influence cortisol, making it easier to interpret results and determine the external social or ecological stressors that may increase cortisol. Am. J. Primatol. 72:600,606, 2010. © 2010 Wiley-Liss, Inc. [source] Western lowland gorillas (Gorilla gorilla gorilla) change their activity patterns in response to frugivoryAMERICAN JOURNAL OF PRIMATOLOGY, Issue 2 2009Shelly Masi Abstract The most important environmental factor explaining interspecies variation in ecology and sociality of the great apes is likely to be variation in resource availability. Relatively little is known about the activity patterns of western lowland gorillas (Gorilla gorilla gorilla), which inhabit a dramatically different environment from the well-studied mountain gorillas (G. beringei beringei). This study aims to provide a detailed quantification of western lowland gorillas' activity budgets using direct observations on one habituated group in Bai Hokou, Central African Republic. We examined how activity patterns of both sexes are shaped by seasonal frugivory. Activity was recorded with 5-min instantaneous sampling between December 2004 and December 2005. During the high-frugivory period the gorillas spent less time feeding and more time traveling than during the low-frugivory period. The silverback spent less time feeding but more time resting than both females and immatures, which likely results from a combination of social and physiological factors. When compared with mountain gorillas, western lowland gorillas spend more time feeding (67 vs. 55%) and traveling (12 vs. 6.5%), but less time resting (21 vs. 34%) and engaging in social/other activities (0.5 vs. 3.6%). This disparity in activity budgets of western lowland gorillas and mountain gorillas may be explained by the more frugivorous diet and the greater dispersion of food resources experienced by western lowland gorillas. Like other apes, western lowland gorillas change their activity patterns in response to changes in the diet. Am. J. Primatol. 71:91,100, 2009. © 2008 Wiley-Liss, Inc. [source] State of the Art Review: Current Status of Topical Nasal Antimicrobial Agents,THE LARYNGOSCOPE, Issue 6 2000Yau Hong Goh FRCS Abstract The nasal cavity and paranasal sinuses are probably one of the last frontiers in the head and neck region where the use of topical antimicrobial agents is not yet established. Although the anatomy of the nasal cavity and the paranasal sinuses can theoretically be exploited for the administration of antimicrobials in rhinosinusitis, very few studies have been conducted to test the feasibility of this mode of therapy. We review the anatomical and physiological factors that should be considered in the use of topical nasal antimicrobial agents and the current status of topical nasal antimicrobial usage, and we make recommendations for the administration of topical nasal antimicrobial agents. [source] Midday depression of photosynthesis and effects of mist spray in citrusANNALS OF APPLIED BIOLOGY, Issue 1 2009M.-J. Hu Abstract Diurnal variations of gas exchange, chlorophyll a fluorescence and some related biochemical characteristics in sun-acclimated mature citrus leaves of mist-sprayed (treatment) and unsprayed (control) trees were compared on sunny days during summer to identify the environmental and physiological factors limiting carbon gain in citrus tree canopies. At midday, net photosynthesis and maximal photochemical efficiency of photosystem II (Fv/Fm) in citrus leaves decreased significantly under control conditions, but the decrease was mitigated by mist spraying. Although the content of malondialdehyde, hydrogen peroxide and activities of antioxidant enzymes increased at midday in both mist-sprayed and control leaves, they were much higher in control leaves than in mist-sprayed leaves. The level of D1 protein decreased significantly in control leaves at midday and then was partly recovered later, while that in treated leaves changed to a much lesser extent because of alleviation of photoinhibition by mist spraying. Both the fast and the slow phases of millisecond-delayed light emissions in treated citrus leaves were higher than those in control leaves, indicating that mist spraying protects the normal operation of the photosynthetic apparatus in leaves. Mist spraying also reduced leaf temperatures and the ratio of air to leaf vapour pressure deficit (ALVPD), leading to increases in stomatal conductance (gs) and alleviation of photoinhibition at midday. It is concluded that the decline of leaf gs under high-ALVPD conditions in summer is an important factor contributing to midday depression of photosynthesis in citrus, and mist spraying is effective in alleviating midday depression of photosynthesis in citrus leaves. [source] Faecal incontinence after lateral internal sphincterotomy is often associated with coexisting occult sphincter defects: A study using endoanal ultrasonographyANZ JOURNAL OF SURGERY, Issue 10 2001Joe J. Tjandra Background: Troublesome faecal incontinence following a lateral internal sphincterotomy (LIS) is often attributed to faulty surgical techniques: division of excessive amount of internal sphincter or inadvertent injury to the external sphincter. The aim of the present paper was to assess the anatomic and physiological factors that may contribute to faecal incontinence following a technically satisfactory lateral internal sphincterotomy by a group of colorectal specialists. Methods: Fourteen patients (nine women, five men; median age: 38 years; range: 23,52 years) who developed troublesome postoperative faecal incontinence were evaluated by clinical assessment, endoanal ultrasonography and anorectal physiological studies (manometry, pudendal nerve terminal motor latency) by two independent observers. The Cleveland Clinic continence score (0,20; 0, perfect continence; 20, complete incontinence) was used to quantify the severity of faecal incontinence. Fourteen continent subjects after a LIS (nine female patients, five male patients; median age: 36 years; range: 20,44 years) were also evaluated as ,continent' controls (continence score , 4). Results: In the incontinent group, the median postoperative Cleveland Clinic continence score was 9 (range: 6,13) compared with a preoperative score of 1 (range: 0,3). On assessment by endoanal ultrasonography the site of the internal sphincterotomy was clearly identified. There were additional coexisting defects, on endoanal ultrasonography, of the external anal sphincter in seven female patients, of the internal sphincter in two female and two male patients; and a defect of both the external and internal sphincters in a male patient who had had a prior fistulotomy. The pudendal nerve terminal motor latency (PNTML) was prolonged in two female patients on the side contralateral to the lateral internal sphincterotomy. In two of five male patients there was no evidence of any occult sphincter injuries. In the continent controls a defect of the distal portion of the external sphincter was noted in one female patient. None of the patients had a prolonged PNTML. The maximum voluntary contraction was significantly lower in the female subjects than in the female continent controls (92 mmHg vs 140 mmHg; P < 0.05), while the resting anal canal pressures and length of the high pressure zone were similar between the study subjects and the continent controls. Conclusion: Troublesome faecal incontinence after a satisfactorily performed lateral internal sphincterotomy is often associated with coexisting occult sphincter defects. [source] ENDOCRINE REGULATION OF CALCIUM TRANSPORT IN EPITHELIACLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 11 2008Ramesh C Khanal SUMMARY 1Calcium (re)absorption occurs in epithelia, including the intestine, kidney, mammary glands, placenta and gills (in the case of fish). 2Calcium is transported across epithelia by two transport mechanisms, paracellular and transcellular, and the movement is regulated by a complex array of transport processes that are mediated by hormonal, developmental and physiological factors involving the gastrointestinal tract, bone, kidney and the parathyroids. 3Clear understanding of the calcium transport pathways and their endocrine regulation is critical for minimizing various metabolic and health disorders at different physiological stages. Here, we first briefly review the calcium transport mechanisms before discussing in detail the endocrine factors that regulate calcium transport in the epithelia. [source] | ||||||||||||||||