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1.
PURPOSE: To determine whether ingestion of a tooth whitener containing 6% hydrogen peroxide as bleaching agent affected the gastric mucosa of adult, female laboratory rats. MATERIALS AND METHODS: Thirty-six fasting rats were intubated with a single bolus (5 g/kg body weight) of the tooth whitener Natural White which contains 6% hydrogen peroxide. Thirty-two control rats received deionized water. Rats were necropsied 15 minutes, 2 hours, 1 and 2 weeks after whitener ingestion. The gastric mucosa was examined histologically and blood hematocrit, glucose, BUN, and bilirubin measured. RESULTS: Six of the 36 rats died within 2 hours of receiving whitener. Within 15 minutes of whitener ingestion, stomachs were grossly bloated with gas. Histological observation showed that gastric mucosal cells were vacuolated and gastric glands dilated. After 2 hours, gastric epithelial and glandular cells had sloughed off into the gastric lumen. Mean blood glucose and hematocrit were significantly (P < 0.05) elevated (233 +/- 41 mg/ml and 50.5 +/- 0.9%) over mean control values (129 +/- 8 mg/ml and 42.8 +/- 2.4%). Within 1 week, the stomachs of experimental rats were no longer bloated, the gastric mucosa appeared normal histologically, but mean blood hematocrit was significantly (P < 0.05) decreased (38.0 +/- 1.5%) from mean control value (43.3 +/- 0.5%). There were no significant differences in mean blood values 2 weeks after whitener ingestion.  相似文献   

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We encountered a rare case of combined intrauterine and extrauterine pregnancy that occurred following separate spontaneous ovulations. A 33 year old woman visited our hospital with the chief complaint of abdominal pain on April 16, 1993. Her last menstruation was from March 23 for 6 days. However, the urinary human chorionic gonadotrophin (HCG) on April 19 was 1024 IU/l. Pelvic examination and ultrasonography indicated an extrauterine pregnancy, which was confirmed by laparotomy and histological identification of trophoblast cells. The urinary HCG concentration markedly decreased after the operation. However, the HCG level increased again on the fifth post-operative day, and a gestational sac (11 mm) was identified in the uterine cavity on the 11th post-operative day, indicating that this intrauterine pregnancy was established following spontaneous ovulation which occurred before the removal of the extrauterine pregnancy. This case indicates that a combined pregnancy can occur not only after simultaneous multiple ovulations but also after the separate spontaneous ovulations.  相似文献   

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The authors examined the effects of caffeine consumption on waiting time to conception in the Reproductive Health Study, a retrospective study of 1,430 non-contracepting, parous women interviewed between July 1989 and June 1990 at Fishkill, New York, and Burlington, Vermont. Information was obtained on 2,501 pregnancies since 1980. Women's reported consumption of caffeinated beverages during the first month of pregnancy was used to estimate daily caffeine intake, which was categorized as none, 1-150, 151-300, and > or = 301 mg. Information on delayed conception was analyzed as a dichotomous variable (< or = 12 months delay vs. > 12 months delay), and the per cycle probability of conception (fecundability) was estimated using waiting time to conception as a continuous variable. Odds ratios of delayed conception and fecundability ratios adjusted for age, parity, smoking, last contraceptive used, infertility history, and race, were estimated by logistic regression and Cox proportional hazard models, respectively. Women who did not smoke and who consumed no caffeine were used as a reference group. The adjusted odds ratio of delayed conception for more than one year was not increased among women who consumed < or = 300 mg of caffeine daily. However, the odds ratio (OR) was 2.65 (95% confidence interval (CI) 1.38-5.07) among nonsmokers who consumed > or = 301 mg of caffeine daily. Although smoking per se was associated with a significant increased risk of delayed conception (OR = 1.77, 95% CI 1.33-2.37), no effect of high caffeine consumption was observed among women who smoked. Fecundability was reduced among nonsmokers who consumed more than 300 mg caffeine daily (fecundability ratio = 0.74, 95% CI 0.59-0.92). Smoking reduced the fecundability ratio, but the authors observed no effect of caffeine consumption on fecundability among women who smoked. Other studies provide biologic plausibility for these findings. The authors conclude that high levels of caffeine consumption may result in delayed conception among women who do not smoke cigarettes.  相似文献   

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The effect of burns on fetal and maternal survival is known to be detrimental. This prospective study describes the performance of pregnant burned patients who were managed and followed up for fetal and maternal outcomes at Ain Shams University's burn unit and Maternity Hospital during the period from October 1995 to September 1996. During the 12-month period, 27 pregnant burned patients were managed. Fetal and maternal mortality correlated with the total body surface area (TBSA) burned, the mortality rate being 63 per cent for both mothers and fetuses in the 25-50 per cent TBSA group. A fetal loss of 56 per cent with no maternal loss were recorded in the 15-25 per cent TBSA group. Experience in dealing with pregnant burned patients proves that early surgical excision and skin grafting, with timely termination of pregnancy are the best lines of treatment. Prevention or minimizing the effects of the burns may be achieved by proper education and guidance of the pregnant woman.  相似文献   

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The activins and inhibins are glycoproteins that belong to the transforming growth factor-beta superfamily and, as such, have diverse effects at many stages during growth and development. Originally identified by their effects on follicle stimulating hormone in males and females, the recent development of specific and sensitive assays for this group of polypeptides has permitted the elucidation of their role in 'fine-tuning' the hypothalamic-pituitary-gonadal axis. This review article focuses on the roles of inhibin and activin in female reproductive physiology with reference to possible future clinical applications in the investigation of infertility and abnormal pregnancy.  相似文献   

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Spontaneous abortions among women working in laboratories, and congenital malformations and birth weights of the children were examined in a retrospective case-referent study. In the spontaneous abortion study there were 535 women (206 cases and 329 referents), and in the malformation study 141 women (36 cases and 105 referents). The analysis of the birth weights concerned 500 women (referents). Significant associations with spontaneous abortion were found for exposure to toluene (odds ratio [OR], 4.7, 95% confidence interval [CI], 1.4 to 15.9), xylene (OR 3.1, CI 1.3 to 7.5) and formalin (OR 3.5, CI 1.1 to 11.2) > or = 3 days a week, adjusted for the covariates. Most of the women exposed to formalin and xylene were working in pathology or histology laboratories. No association with congenital malformation was found.  相似文献   

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In a retrospective study is examine the effect of a previous state of sterility on the outcome of pregnancy and labor. For two years (1993-1994) there were 203 (2.6%) women who gave birth after 6.7% +/- 3.5 years of sterility. From the study are excluded 9 women (4.4%) with multifetal pregnancies and 13 cases (6.4%) with different diseases, which may adversely affect the pregnancy of the foetus. In the study group of 181 primiparous women the rate of premature labor is 2.2% which is significantly lower than the hospital incidence (11%) for the same period. The cesarean section (CS) rate after period of sterility is unreasonably high--69%. In the subgroup scheduled for vaginal labor CS are performed in 34% of cases. The indications for the elective CS are complex, less justifiable and partially due to non medical reasons. The past period of sterility has not adverse effect on the course of the vaginal labor or the state of the newborn at delivery.  相似文献   

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Male pesticide exposure and pregnancy outcome   总被引:1,自引:0,他引:1  
Potential health effects of agricultural pesticide use include reproductive outcomes. For the Ontario Farm Family Health Study, the authors sampled Ontario farms from the 1986 Canadian Census of Agriculture, identified farm couples, and obtained questionnaire data concerning farm activities, reproductive health experience, and chemical applications. Male farm activities in the period from 3 months before conception through the month of conception were evaluated in relation to miscarriage, preterm delivery, and small-for-gestational-age births. Among the 1,898 couples with complete data (64% response), 3,984 eligible pregnancies were identified. Miscarriage was not associated with chemical activities overall but was increased in combination with reported use of thiocarbamates, carbaryl, and unclassified pesticides on the farm. Preterm delivery was also not strongly associated with farm chemical activities overall, except for mixing or applying yard herbicides (odds ratio = 2.1, 95% confidence interval 1.0-4.4). Combinations of activities with a variety of chemicals (atrazine, glyphosate, organophosphates, 4-[2,4-dichlorophenoxy] butyric acid, and insecticides) generated odds ratios of two or greater. No associations were found between farm chemicals and small-for-gestational-age births or altered sex ratio. Based on these data, despite limitations in exposure assessment, the authors encourage continued evaluation of male exposures, particularly in relation to miscarriage and preterm delivery.  相似文献   

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Pronounced physical exertion may influence intraabdominal pressure and uterine blood flow, hormonal balance, and nutritional status, all of which are important determinants of embryonic and fetal development and survival. Most of the epidemiologic evidence of reproductive effects from occupational physical activity concerns gestational age/premature birth, birth weight/intrauterine growth retardation, and spontaneous abortion. Strenuous work, especially when involving long hours of standing and walking, seems to increase the risk of preterm delivery. The effect on intrauterine growth and spontaneous abortion risk is less clear. As a single factor, heavy lifting has in most circumstances not been associated with a significantly increased risk of these outcomes. In general, heavy work duties should be avoided, and enough rest periods assured, especially in late pregnancy.  相似文献   

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To investigate the change in adult T-cell leukemia incidence between 1983 and 1992 and to evaluate the sensitivity of the nationwide adult T-cell leukemia survey, we estimated adult T-cell leukemia incidence in the Kyushu district, southern Japan, where adult T-cell leukemia is endemic. The incidence of adult T-cell leukemia was calculated from the difference between Kyushu and the rest of Japan in mortality from malignant lymphoid neoplasms, i.e., Kyushu's excess rate was assumed to be due to adult T-cell leukemia. In Kyushu, average annual adult T-cell leukemia cases aged > or = 20 years were estimated for men as 252 during the period 1983-87 and 341 during 1988-92, and for women as 201 and 246 respectively. The age-adjusted mortality rate tended to be higher in the latter period [6.29 per 100000 (95% confidence interval 5.59-7.00) vs. 5.25 (4.60-5.90) in men, and 3.33 (2.85-3.80) vs. 3.18 (2.71-3.66) in women]. By contrast, the registered number of adult T-cell leukemia cases nationwide during 1988-93 was only 35% (203/587) of the estimated number, and the number of registered versus estimated cases decreased with age, especially when cases were > 60 years old. In conclusion, the estimated adult T-cell leukemia incidence for 1983-92 increased in the latter half of the period. The estimation suggests that 65% of adult T-cell leukemia cases might be missed by a nationwide survey, and older cases were more likely than younger ones to be missed.  相似文献   

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We present an assessment of studies published in the last decade that consider the relationship of stress and social support to preterm delivery or fetal growth retardation. Included in the review are all reports on the direct effects of stressors or psychological distress; the indirect effects of stressors or distress through health behaviours such as smoking; and the direct and buffering effects of social support. Although an important stimulus for recent stress research has been the attempt to explain racial and social class differences in birth outcome, the recent data show that stressful life events during pregnancy, though more common in disadvantaged groups, do not increase the risk of preterm birth. In contrast, intimate social support from a partner or family member appears to improve fetal growth, even for women with little life stress. Questions unanswered by the research to date are whether elevated levels of depressive symptoms affect pregnancy outcome, either directly or by encouraging negative health behaviours, and whether chronic (vs. acute) stressors are harmful. Additional research is also needed to determine whether psychosocial factors interact with specific clinical conditions to promote adverse pregnancy outcomes. Focusing on intimate support and how it benefits pregnancy outcome could lead to the design of more effective interventions.  相似文献   

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Estimated verbally and numerically the chances that specific events will occur using 6 analysts. 60 decision makers used each type of estimate to make binary-choice decisions and to bid for lotteries based on the events. The usual reversal of preference between choice and bidding procedures was found in the numerical condition, but the frequency of preference reversals was significantly reduced in the verbal condition. This reduction occurred because risk aversion was reduced in choice when verbal estimates were given, whereas bidding was unaffected by presentation mode. The pattern of results was predicted by and supports the hypothesis that the relative importance given to the dimensions of a prospect depends on the form in which the information is displayed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

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OBJECTIVE: Animal work suggests that maternal oxytocin secretion is influenced by the secretion of endogenous opioids in pregnancy. Spontaneous labour and pre-labour uterine activity follow a 24-hour rhythm the origin of which has not been explained but may be related to diurnal changes in oxytocin secretion. This study was performed to document the changes over a 24-hour period in maternal oxytocin and beta-endorphin secretion. DESIGN: A 4-hourly blood profile was undertaken for a 24-hour period. PATIENTS: Sixteen women with singleton pregnancies of more than 36 weeks gestation and 10 women with pregnancies in the mid trimester were studied. MEASUREMENTS: Blood was sampled 4-hourly for 24 hours beginning at 1200 h. Oxytocin was measured in all patients and beta-endorphin-like immunoreactivity was measured in 15 patients. RESULTS: A simple index was defined for comparing night-time levels to daytime levels for both oxytocin and beta-endorphin. In all cases more than 36 weeks gestation the index was positive for oxytocin (night-time levels were higher) and in all cases the index was negative for beta-endorphin (night-time levels were lower). In the mid trimester women all values of the index for oxytocin were positive but in the beta-endorphin group equal numbers demonstrated a positive or a negative index. CONCLUSIONS: Reciprocal 24-hour rhythms were demonstrated between oxytocin and beta-endorphin; however, it is not clear whether this relationship is causal.  相似文献   

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The role of nocturnal sleep for normal immune regulation and its relation to circadian rhythm was examined in 10 men participating in two 51-h sessions. One session included two regular wake-sleep cycles; the other included a night of sustained wakefulness followed by a night of recovery sleep. Blood was collected every 3 h to determine PBMC counts, including the enumeration of monocytes, NK cells, and lymphocyte subsets (CD19+, CD3+, CD4+, CD8+, HLA-DR+). Production of IL-1beta, TNF-alpha, IL-2, and IFN-gamma was determined after stimulation of whole blood samples with LPS and PHA, respectively. Concentrations of IL-6 and cortisol were assessed in plasma. Enumeration of cells indicated significant circadian rhythms for all PBMC subsets under conditions of sustained wakefulness. Compared with sustained wakefulness, nocturnal sleep acutely reduced the numbers of monocytes, NK cells, and counts of all lymphocyte subsets. However, in the afternoon and evening of the day following sleep, counts of NK cells and lymphocytes were significantly higher than after nocturnal wakefulness, indicating that effects of sleep interacted with those of the circadian pacemaker. Sleep markedly enhanced production of IL-2 by T cells (CD3+) but did not influence production of IL-1beta and TNF-alpha, or IL-6 concentrations. Effects of sleep were not mediated by changes in cortisol. The decrease in monocytes, NK cells, and lymphocytes, together with an increased production of IL-2 during sleep, may serve to support ongoing immune defense in extravascular lymphoid tissue during a time of diminished acute Ag challenge.  相似文献   

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