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PubMed2000

[Seasonal variation and influence of atmospheric pressure diurnal fluctuations on occurrence of acute complications in patients with stomach and duodenal ulcer].

Although there is rich literature concerning seasonal fluctuations of incidence of peptic ulcer, no one can find so many data on acute complications of this disease--bleedings and perforations. There is also only little information saying about the role of meteorological factors that can take part in occurrence of the mentioned complications. This study aimed to analyze the seasonal variation (in calendar months, quarters of the year and calendar seasons--winter, spring, summer, autumn) of peptic ulcer bleeding and perforations as well as the influence of atmospheric pressure diurnal fluctuations on the occurrence of these diseases. The conducted study was retrospective and based on data of patients admitted to III Department of General Surgery of the Jagiellonian University Medical School in Cracow. Altogether, from 1993 to 1997--26 patients with peptic gastroduodenal ulcer bleeding were admitted. 220 bleedings were endoscopically proven (6 patients did not agree for gastroscopy and were excluded from further analysis). 157 patients were treated because of peptic ulcer perforation at the same time and all of them underwent surgical procedure during which perforation was proven. The chi 2 test was used in order to verify our statistic hypothesis (p = 0.05). The examination did not show any significant seasonal variation of the studied complications. Neither hemorrhage nor perforation presented any seasonal prevalence. As for calendar months, quarters and calendar seasons (p > 0.01; p > 0.02; p > 0.02 respectively). However, the study confirmed the role of atmospheric pressure falls in the occurrence of both: bleeding and perforation of peptic ulcer (p < 0.001). 153 patients with bleeding were admitted on days with decreasing pressure, while 67 when pressure was going up. Similarly as for perforations--94 with falling down to 33 with growing up pressure.

Aged↗
PubMed1979

Seasonal variations in the occurrence of urinary tract infections among children in an urban area in Finland.

The seasonal variations in the incidence of urinary tract infections (UTI) were studied in a series of 992 verified episodes of UTI treated between 1965 and 1974. The incidence was highest during November and lowest during the summer months. Summer episodes, moreover, tended to be the most severe. Seasonal variations were less marked among girls, than amond boys, except in the group of teenage girls in which peak incidences occurred in March and in September. Among the boys, a single peak incidence was recorded in July. The results of the analysis of weather type performed in this study showed that unseasonable types of weather, that is, cold and dry weather in autumn, warm and rainy weather in winter, and warm and dry weather in spring, were accompanied by a clear increase in the monthly number of episodes of UTIs. The difference in the monthly frequency of UTIs between the most and the least favourable types of weather was about two-fold.

Adolescent↗
PubMedDate not supplied

Seasonal variation of the chemical constituents from Croton species.

The terpenes, sterols, alkaloid (glaucine) and alpha-tocopherol show seasonal variation for Croton hemiargyreus hemiargyreus and Croton echinocarpus. The amounts of triterpenes are higher during the tropical summer and in most samples the major sesquiterpene was characterized as caryophyllene. The seasonal variation of glaucine showed a maximum between June and October for C. hemiargyreus, and was present only in January and June in C. echinocarpus.

Brazil↗
PubMed1991

Seasonal variations in the antioxidant defence systems and lipid peroxidation of the digestive gland of mussels.

1. The seasonal variations in the level of antioxidant compounds (glutathione (GSH), vitamin E, carotenoids) and in the activity of antioxidant enzymes, superoxide dismutase (EC 1.15.1.1), catalase (EC 1.11.1.6), GSH-peroxidase (EC 1.11.1.9) in the digestive gland of mussels (Mytilus sp.) were evaluated. The lipid peroxidation process was also measured by determining the tissue concentration of malondialdehyde (MDA). 2. The physiological fluctuations of the antioxidant defence systems were inversely related to the accumulation of lipid peroxidation products (MDA) in the tissue. The observed seasonal variations are presumably related to the changing metabolic status of the animals, itself dependent on such factors as gonad ripening and food availability. 3. In particular, the obtained data indicate that a reduction of the antioxidant defence systems, occurring during winter, could be directly responsible for an enhanced susceptibility of mussels tissues to oxidative stress, as indicated by the high MDA concentration observed in this period.

Animals↗
PubMed1997

Seasonal variation of gonadotropins and gonadal steroids receptors in the human pineal gland.

Recently abnormal melatonin secretion was demonstrated in hypogonadal male patients which was normalized during testosterone administration. These results suggested that both gonadal steroids and gonadotropins may modulate melatonin secretion, probably by activating specific receptors in the pineal gland. We used immunohistochemistry to localize luteinizing hormone, follicle stimulating hormone, estrogen and androgen receptors in human pineal glands. Tissues were obtained at autopsy from 53 adult males (aged 19-94 years) over a period of 1 year. Positive staining for the four types of receptors was evident in all 53 specimens examined. The percent of positively stained cells revealed a significant seasonal variation of gonadotropin receptors with higher values in the winter than in the summer. Day-night difference was evident only for follicle stimulating hormone-receptors during the summer and winter, with higher values at night. Androgen receptors and estrogen receptors were present in all specimens but did not reveal day-night or seasonal variations. These data demonstrate the presence of gonadotropin and gonadal steroid receptors in the human pineal gland. Gonadotropin receptors exhibited seasonal variation with higher values in the winter.

Adult↗
PubMed2006

[Seasonal variation of Aedes aegypti and Aedes albopictus in a city of Southeastern Brazil].

OBJECTIVE: To assess the seasonal variation of Aedes aegypti and Aedes albopictus and to estimate the association between the species abundance and abiotic factors. METHODS: Tire-traps were kept for a period of 15 days monthly in an urban area of the city of Potim in the state of São Paulo, Southeastern Brazil, from November 2002 to October 2003. Samples of immature forms were followed up under laboratory conditions for 29 days and species were identified. The association between abundance and temperature, rainfall and air relative humidity was tested using Spearman correlations (r s). The descriptive statistics were presented by the average and the standard error (alpha=0.05). RESULTS: From a total of 20,727 immatures collected, 95.3% were Ae. aegypti and 4.7%, Ae. albopictus. Ae. aegypti was found throughout the whole year while Ae. albopictus was found from November to July. The association between these species and abiotic factors was significant for Ae. aegypti (p=0.04) as for maximum temperature and for Ae. albopictus as for maximum temperature (p=0.01) and rainfall (p=0.02). CONCLUSIONS: Both species presented seasonal variation. However, Ae. aegypti was found throughout the whole year showing a decrease between April and May and June and July. Ae. albopictus, less abundant, was found only between November, 2002 and July, 2003 with a peak in April, 2003. The higher abundance of Ae. aegypti compared to Ae. albopictus in an urban area showed Ae. aegypti has greater capacity of colonizing tires. Such a breeding site in the environment may be important to the maintenance and abundance of Ae. aegypti.

Aedes↗
PubMed1991

[Seasonal variations of lipids and arterial pressure].

BACKGROUND: The presence of a seasonal variation in serum lipids and blood pressure is often described in the literature. METHODS: With the aim of analyzing this seasonal influence blood pressure and lipid (total cholesterol and cholesterol corresponding to different lipoprotein, triglycerides and AI and B apolipoprotein families) values were studied over 12 months in 36 normotense healthy males (mean age 36 +/- 6 years), a third of whom presented diverse base lipid alterations. A variance analysis of the relative intraindividual values (to study monthly differences) was carried out and a Student's t test was performed for the absolute values and grouped into two periods (summer and winter) and according to two categories (normal and hyperlipemic). RESULTS: No significant modification was observed in any of the parameters studied with the exception of the intrapersonal variation coefficient of the triglycerides which was significantly higher in the hyperlipemic individuals. CONCLUSIONS: In the population studied no seasonal modification was observed in blood pressure or different lipid concentrations analyzed. The slight variation of temperature observed and the elevated sunstroke in Spain in addition to the youth of the population studied may explain the lack of seasonal variation.

Adult↗
PubMedDate not supplied

Seasonal variations of cerebral palsy births in northeastern Poland.

BACKGROUND: The objective of this report was to examine the seasonal variations on the incidence of cerebral palsy (CP) in Podlasie province, Poland in a retrospective case-control study. METHODS: Data were obtained from the Department of Pediatric Neurology and Rehabilitation. Selected babies were all born between January 1, 1990 and December 31, 1999; 212 children (116 boys, 96 girls) with CP were included in the study. We applied Cosinor analysis to examine the seasonality of CP births. RESULTS: The highest number of CP births occurred in spring and the lowest in winter, with intermediate values in summer and autumn. This seasonal pattern was significant for spring vs. winter. The peaks in CP births occurred in May and August. The lowest number of CP births occurred in February and December. We also demonstrated seasonal variation in CP births in girls and boys and Apgar score. Peaks in CP births in boys were noted in May and October and Apgar score in May and December, respectively. No significant relationship between mean temperature and Apgar score, low birthweight and asphyxia was found. CONCLUSIONS: These data suggest the seasonal patterns of CP births. Further studies should be performed with larger numbers of patients.

Birth Rate↗
PubMed2003

Seasonal variation in the frequency of abnormal anaphases and mitotic index values in wild populations of herb-Paris (Paris quadrifolia L., Trilliaceae): implications for genetic monitoring.

The main aim of our study was to investigate seasonal variation in the frequency of abnormal anaphases and mitotic index values in wild populations of herb-Paris (Paris quadrifolia L., Trilliaceae). Plant material was collected in the year 2000 in Norway and in the year 2001 in Lithuania. There was statistically significant variation in the mitotic index values (chi(2)=1087.9, d.f.=16, P<0.0001) with the highest values during the active growth period in May and the lowest values at the end of vegetation period in September. Seasonal variation in the frequency of abnormal anaphases was statistically significant as well (chi(2)=28.23, d.f.=16, P=0.0297). The most frequent type of anaphase abnormality was vagrant chromosomes (64.2%) followed by bridges (28.6%), fragments (3.6%), sticky chromosomes (2.4%) and multipolar anaphases (1.2%). During the fieldwork, quite deep late frosts occurred. Mitotic index was lower in the plants collected immediately after the frosts or 1 week later than in the plants sampled before the frosts (52+/-13 and 123+/-15, respectively, P=0.0014). On the contrary, frequency of abnormal anaphases was statistically significantly elevated (P=0.0082) in plants after the frosts (6.35+/-1.54%) when compared to plants before the frosts (2.49+/-0.56%). Our results clearly indicated significant variation in the mitotic index values and frequency of abnormal anaphases in the wild populations of herb-Paris during the growth season. This variation may be related to the physiological conditions of the analysed plants as well as to certain ecological factors.

Anaphase↗
PubMed2003

Seasonal variation in relapse rate of graves' disease after thionamide drug treatment.

OBJECTIVE: Controversy abounds on the issue of seasonal variation in new onset of Graves' disease, partly due to the difficulty of precisely dating the exact start of symptoms. To address the possible relationship between climatic changes and disease activity from a different perspective, we reviewed time of relapse during regular follow-up after successful drug treatment with thionamides. DESIGN: Retrospective analysis of a case series in a university clinic. PATIENTS AND MEASUREMENTS: We consecutively registered patients who experienced re-emergence of hyperthyroidism between 1992 and 2001 after successful antithyroid drug therapy. Excluded were subjects with superimposing painless thyroiditis, in postpartum, on immunomodulatory drugs, or off thionamides prematurely on their own volition. RESULTS: Fifty-two patients recurred 2 to 36 months after drug cessation. The frequency was higher in spring and summer (March to August) than in autumn and winter (September to February). With a new coated-tube radioreceptor assay, TSH binding inhibitor immunoglobulin activity was detected in sera from 87.5% of the reworsened patients. CONCLUSIONS: Graves' disease tends to relapse more frequently in spring and summer. Further clinical studies are warranted to clarify underlying mechanism (s) for this seasonal variation.

Adult↗
PubMedDate not supplied

Microscopic evaluation and seasonal variations of anthraquinone glycosides of cultivated Cassia fistula Linn.

In this report, we present the results of the microscopy, seasonal variations and spectrophotometric estimation of hydroxy-anthraquinone glycosides of culitivated Cassia fistula Linn. The total glycoside contents ofthe morphological parts of this species at different stages of growth are also presented. The study shows that anthraquinone glycosides are concentrated in the leaves (1.75%) and flowers (1.58%) at peak flowering. Notable seasonal variations were observed in the cultivated species. Hydroxyanthraquinones reached peak levels druing the months of September (1.08%) and October (2.20%). There was a significant drop (P < 0.05) in glycoside content during most part of the rainy season. It has been established that anthraquinone glycosides, rather than the aglycones, are the active forms and hence an estimation of the total glycoside content of a sample is a reliable indication of biological activity. The advantages of using the natural anthraquinone laxative when the glycoside content is highest are discussed. The study has provided useful information on the best period for harvesting the morphological parts of C. fistula for drug development.

Anthraquinones↗
PubMed2004

Seasonal variation in perceived indoor environment and nonspecific symptoms in a temperate climate.

Few epidemiological studies have examined the effects of season on symptoms typical of sick building syndrome (SBS). The present study aims to clarify seasonal variation in a perceived indoor environment and SBS symptoms in a temperate climate. A total of 116 workers were recruited from office buildings in southern Japan that presented no apparent serious indoor problems. A validated questionnaire was distributed four times, once at the end of each season. Seasonal effects on the perceived indoor environment and SBS symptoms were investigated with a parametric test for repeated measurement of categorical data. Logits were used as the response function, and were compared to overall logits to determine the relevant odds ratios (OR). The effect of season/building interaction was also evaluated. Significant seasonal variation in the perceived indoor environment was found for temperature, dryness, air stuffiness, and static electricity (p for season, <0.05), although the seasonal patterns for temperature and dryness differed according to the building (p for interaction, <0.05). Symptoms in the mucous membrane (eyes, nose, and throat) and skin increased considerably in the winter and spring (p for season, <0.05), whereas general symptoms varied little, but such seasonality of symptoms was not modified by the building factor. The associations between perception of indoor environments and mucous and skin symptoms became stronger during winter and spring. The present results suggest that perceived indoor environments, nonspecific symptoms and their associations are closely associated with the season among office workers in a temperate climate.

Air Pollution, Indoor↗
PubMed2000

Seasonal variation in risk of anemia among pregnant Nepali women.

OBJECTIVE: We aimed to investigate whether there is any seasonal variation in risk of anemia among pregnant Nepali women. METHODS: We studied the hematocrit values in pregnant women (n=5495) attending Patan Hospital, Kathmandu for the first antenatal visit in the 2-year period from January 1994 until December 1995. In a sub-sample of subjects (n=2706), additional information was obtained through interviews and clinical examinations. Logistic regression models were used to analyze data. RESULTS: Mean hematocrit values recorded in the monsoon period were significantly lower than hematocrit values recorded in the winter. The prevalence of moderate (hematocrit 25-33%) and severe (hematocrit<25%) anemia was highest in September. CONCLUSIONS: We found a clear seasonal variation in risk of anemia, which was associated with rainfall and temperature. The monsoon seems to be a period when interventions may give the most beneficial effects.

Adolescent↗
PubMed2005

Seasonal variation of nitrogen-concentration in the surface water and its relationship with land use in a catchment of northern China.

Surface waters can be contaminated by human activities in two ways: (1) by point sources, such as sewage treatment discharge and storm-water runoff; and (2) by non-point sources, such as runoff from urban and agricultural areas. With point-source pollution effectively controlled, non-point source pollution has become the most important environmental concern in the world. The formation of non-point source pollution is related to both the sources such as soil nutrient, the amount of fertilizer and pesticide applied, the amount of refuse, and the spatial complex combination of land uses within a heterogeneous landscape. Land-use change, dominated by human activities, has a significant impact on water resources and quality. In this study, fifteen surface water monitoring points in the Yuqiao Reservoir Basin, Zunhua, Hebei Province, northern China, were chosen to study the seasonal variation of nitrogen concentration in the surface water. Water samples were collected in low-flow period (June), high-flow period (July) and mean-flow period (October) from 1999 to 2000. The results indicated that the seasonal variation of nitrogen concentration in the surface water among the fifteen monitoring points in the rainfall-rich year is more complex than that in the rainfall-deficit year. It was found that the land use, the characteristics of the surface river system, rainfall, and human activities play an important role in the seasonal variation of N-concentration in surface water.

China↗
PubMed1999

Seasonal variation of semen quality and fertility.

At many locations in the northern hemisphere human sperm counts are reduced during the summer. Experiments with rhesus monkeys suggest that such seasonal variation may be induced by an endogenous biological clock reset annually by changes in the length of daylight. Little is known about seasonal variation in human female reproductive function, although fecundity may be lower during the summer, as it is for men. Variation in fecundity could help explain seasonal patterns of birth in countries such as the United States, where there is a deficit of spring births. But the relationship to patterns of birth in Canada and Europe, where the birth rate is highest during late winter and spring, is unclear.

Animals↗
PubMed1998

Seasonal variations in hospital treatment periods and deaths among adult asthmatics.

The purpose of this study was to examine possible seasonal variations in relations between hospital treatment periods and in deaths (asthma-related and other) among adult asthmatics. Out of a total of 364,871 asthma-induced hospitalization periods (diagnosis No. 493, International Classification of Diseases) recorded in the hospital discharge register maintained by the National Research and Development Centre for Welfare and Health during 1972-1992, all of those applying to persons aged >24 yrs during 1987-1992 were analysed here. The discharge file was linked to the register of deaths on the basis of the patients' social security numbers in order to analyse all deaths among the same patients during 1987-1993. A total of 81,243 asthma-related treatment periods were analysed. The monthly variation in the number of such periods showed a peak in January (18.2% above the mean number of monthly deaths in the study period) and a trough in July (26.1% below the mean). Of the 7,622 hospitalized asthmatics who died during the period examined here, 1,274 died of obstructive pulmonary diseases, with asthma as the primary cause in 489 cases. The majority of the deaths were caused by cardiovascular diseases. Mortality was highest in January (+14.7%) and lowest in August (-12.3%). The similarity in the seasonal variation observed between the treatment periods and deaths recorded for adult asthmatics may be taken to indicate a genuine need for treatment.

Adult↗
PubMed2004

Seasonal variations in the activity budget of Japanese macaques in the coniferous forest of Yakushima: effects of food and temperature.

Seasonal variations in the activity budget of Japanese macaques in the coniferous forest of Yakushima were studied over the course of 1 year. On an annual basis, they spent 38% of the daytime feeding, 16% traveling, 14% in social interactions, and 32% engaged in resting. The effects of temperature and food-related factors (i.e., food distribution, feeding speed, and food abundance) on the seasonal variations of activity budget were examined by stepwise multiple regression analysis. When the temperature was low, the macaques decreased traveling and feeding time, in accordance with the prediction that endothermal animals save energy under severe thermoregulatory cost. When the feeding speed of available foods was slow, they spent more time feeding. When high-quality foods were abundant, they decreased feeding time. These macaques did not respond to fluctuations in food distribution. The present results indicate the importance of temperature, in addition to food-related factors, as a determinant of activity budgets.

Animals↗
PubMed1992

Sexual differences and seasonal variations in vasoactive intestinal peptide immunoreactivity in the suprachiasmatic nucleus of jerboa (Jaculus orientalis).

The sexual differences and the seasonal variation in the vasoactive intestinal peptide (VIP) content of the suprachiasmatic nucleus (SCN) of a desert rodent, the jerboa (Jaculus orientalis) were studied using immunocytochemical techniques. During the period of sexual activity (spring-early summer), the VIP immunoreactivity in the SCN was higher in females than in males. In the period of sexual quiescence (autumn), both males and females exhibited an even more intense VIP immunoreaction in the SCN as compared to spring. However, during this period, the sex-related differences in the VIP content of the SCN observed in spring were no longer detectable. The direct possible influence of sex hormones on the VIP content in the SCN, and the physiological significance of the seasonal variation observed in the VIP immunoreactivity in the SCN in this species remains to be determined.

Animals↗