首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Quantitative stimulation of frog olfactory receptors   总被引:8,自引:0,他引:8  
  相似文献   

2.
This study examined the duration of the effect of early olfactory experience in rats by determining the ease of conditioning and then reconditioning to an early-experienced odor. Rat pups (experimental group) were exposed to aniseed odor sprayed on the mother's belly from day 1 to 20 after birth. A control group was exposed only to water. At the ages of 21 and 40 days all the rats (experimental and control) were tested for preference for the odor of aniseed. Starting from day 41 after birth they were conditioned in a Y-maze to approach the odor of aniseed for a reward. We then divided both groups into five subgroups each. Each subgroup was retrained to approach aniseed after 5, 6, 7, 8 or 9 months, and their speeds of reconditioning to the odor were compared. The results showed that all rats in the early exposed group had remembered the odor and did not require reconditioning, unlike those in the group that had not had the early olfactory conditioning. The effect of the early experience was still detectable at least 5 months after last exposure to the odor.  相似文献   

3.
The aberrant methylation of cytosine residues in the promoter region of growth regulatory genes is now widely recognized as an additional mechanism for gene inactivation in cancer cells. In this study we analyzed the methylation status of four growth regulatory genes (p16, RASSF1A, cyclinD2, 14-3-3zeta) during breast cancer progression. For this purpose invasive and noninvasive tumor cell populations as well as hyperplastic cell proliferations were isolated from a series of archival breast tissue specimens (n = 57) using laser-assisted microdissection. A new real-time polymerase chain reaction-based assay was used for the sensitive and quantitative determination of the cell-specific methylation status. We found that aberrant promoter methylation was already prevalent in pure intraductal carcinoma with different frequencies and different methylation levels for the four genes analyzed. For RASSF1A and 14-3-3zeta promoter methylation was also demonstrated in epithelial hyperplasia and intraductal papillomas. By contrast, aberrant methylation of cyclinD2 and p16 was restricted to cancerous epithelium. Increased methylation of the cyclinD2 gene was significantly associated with a higher van Nuys grade. Furthermore, when intraductal and invasive tumor cells were compared, significant quantitative changes in the methylation level were detected primarily within the cyclinD2 gene. These results demonstrate that promoter methylation is an early and frequent event in breast cancer development, but displays great quantitative and gene-specific differences, and changes in a gene-specific manner during tumor progression.  相似文献   

4.
The prevalence and incidence of genital herpes are increasing worldwide. Conversely, the incidence of neonatal herpes shows global discrepancies: very higher numbers of cases are reported in parts of the USA, whereas rates remain low across much of Europe. As illustrated by the French experiences reported here, regionally appropriate management strategies for genital herpes during pregnancy do not alone account for differences in neonatal herpes rates.  相似文献   

5.
This study assessed four psychological factors that have been suggested by previous research to be highly correlated with drug use. Twenty-one postpartum urban African-American women served as the research participants. At parturition, 10 infants tested positive for cocaine and 11 did not. Measures of depression (Beck Depression Index), anxiety (Spielberger Trait Anxiety Inventory), anger/self-control (Self-Analysis Questionnaire), and sociopathy (California Personality Inventory subscale) were obtained from the mothers within 6 weeks of delivery. Women who gave birth to cocaine-positive infants were significantly more depressed and had significantly higher sociopathy scores than their cocaine-negative counterparts. No differences with respect to anxiety and anger were obtained. The implications of these findings, as well as the potential adverse effects of cocaine use during pregnancy, are discussed.  相似文献   

6.
7.
8.
1. A means of quantitating left ventricular performance in the conscious dog is presented. Changes in heart rate, stroke volume and cardiac output during elevation of left atrial pressure by acute volume expansion were measured in the conscious dog. 2. The changes in heart rate and stroke volume could be described by y = ym - (ym-yi)e-kp, where yi and ym are initial and maximum values of the variable and p is the change in mean left atrial pressure. 3. Because cardiac output is a derived variable (stroke volume X heart rate) its response is described by a multiple exponential relationship. 4. For a given initial heart rate and inotropic state, the stroke volume response is determined by the Frank-Starling mechanism and the pressure-volume characteristics of the myocardium.  相似文献   

9.
10.
<正>宫外孕即受精卵在子宫腔以外着床发育的异位妊娠,是妇科常见急症,发病急,病情重。输卵管妊娠是最常见的异位妊娠,当输卵管妊娠破裂引起大出血时可能危及生命。手术是治疗宫外孕的主要手段,与传统的开腹手术相比,腹腔镜手术切口小、损伤少、出血少、住院时间短、术后恢复快[1]。现将宫外孕腹腔镜手术的护理体会总结报告如下。1临床资料我科于2011年1月至2012年12月共完成腹腔镜宫外孕  相似文献   

11.
Surgical ablation of the olfactory bulbs was used to study the influence of olfaction on estrus induction in M. o. ochrogaster. Of 112 females pretested, 78% were induced to estrus. From a group of 56 operated females, 23 were completely bulbectomized (CB) and 33 were partially bulbectomized (PB) as determined from either microscopic or gross inspection. When housed cage-within-cage with males, CB females failed to become estrus. Similar tests using PB females results in 61% of these animals becoming estrus. When the females were housed in cages with males for one week, the frequency of pregnancy was 17% and 67% for the CB and PB females respectively. Thus, the response following partial bulbectomy was variable. The results show that complete bulbectomy blocked estrus induction and suggest that in this species male induced estrus is mediated via olfaction.  相似文献   

12.
An assessment of the salient olfactory environment of formula-fed infants.   总被引:2,自引:0,他引:2  
Olfactory preferences of two-week-old bottle-fed infants were assessed in a series of simultaneous two-choice tests. Infants of each sex displayed preferential orientation to a stimulus pad worn on their mother's breast over a clean control pad. When maternal breast odor was paired with the odor of the infants' formula, however, boys spent more time oriented toward the formula odor, whereas girls evinced no reliable preferences. Although the subject infants had no prior direct contact with odors emanating from the breasts of lactating females, but had recurring reinforced exposure to the odor of their familiar formula (in the context of feeding), the former scents elicited a more positive response. Preferential orientation to lactating-breast odors reflects adaptive inborn attraction to cues associated with the natural food source for human neonates.  相似文献   

13.
AIMS: To assess quantitatively both the morphological changes in the rectal mucosa and the changes in the relative frequency of IgA and IgG subclass producing cells found in the rectal mucosa during the acute phase of shigellosis and at convalescence. METHODS: Rectal biopsies from 25 Shigella dysenteriae 1 infected patients, 10 Shigella flexneri infected patients, and 40 uninfected controls were studied. Morphological changes in the mucosa were graded. The frequency of IgA and IgG subclass producing cells was assessed. In addition, immunostaining for secretory component in epithelial cells was analysed. RESULTS: Using morphological grading, 20% of the 35 patients studied had advanced inflammation (grade 3) in the acute phase of the disease. At convalescence, grade 1 inflammation was seen in 37% of the patients and in 10% of the controls. In the acute phase, as well as at convalescence, the number of IgA1, IgA2, and IgG2 positive cells was significantly higher than in the controls. The results were related to the histopathological degree of inflammation. CONCLUSIONS: In shigellosis, there is evidence for a prolonged humoral response residing in the mucosa long after the clinical symptoms have resolved, suggesting that shigellosis induces persisting mucosal humoral immune and inflammatory responses, remaining at least until 30 days after the infection.  相似文献   

14.
PURPOSE: 1) To identify morphometric characteristics in hemizygous patients with Fabry disease a treatable lysosomal storage disorder caused by the deficiency of alpha-galactosidase A where morphological abnormalities have occasionally been mentioned, but have never been investigated systematically. 2) To devise a quantitative method to evaluate dysmorphic abnormalities in Fabry disease. METHOD: Cross-sectional, single center, independent dysmorphology assessment by a panel of three clinical geneticists, based on standardized medical photography. Population: consecutive hemizygous patients with Fabry disease (N = 38) unselected for the features assessed, mean age 38 +/- 10.8 years (range: 10-60), recruited for neuropathic pain into enzyme replacement therapy trials. RESULTS: The following dysmorphic features were identified (in order of descending frequency): periorbital fullness, prominent lobules of the ears, bushy eyebrows, recessed forehead, pronounced nasal angle, generous nose/bulbous nasal tip, prominent supraorbital ridges, shallow midface, full lips, prominent nasal bridge, broad alar base, coarse features, posteriorly rotated ears, and prognathism. Extremity features included broad fingertips, short fingers, prominent superficial vessels of hands, 5 digit brachydactyly, and 5 digit clinodactyly. Narrow anterior-posterior chest diameter was noted. Ten core features were statistically defined. Cronbach's alpha measuring internal consistency was 0.62. Light's kappa for global inter-rater variability was 0.26 while Cohen's kappa allowing pair-wise rater comparison varied between 0.08-0.48. CONCLUSIONS: Patients with Fabry disease share common morphological characteristics of the face, trunk, and extremities. Some of these features are subtle as documented by the inter-rater variability. Awareness of these features may facilitate the diagnosis of patients with Fabry disease, and identification of affected family members.  相似文献   

15.
The purpose of this study was to investigate determinants of the activity patterns of women prior to pregnancy and factors associated with quitting activities during pregnancy. METHODS: These data arose from a study designed to look at the impact of exercise in pregnancy on birth weight (Campbell and Mottola, 2001). This secondary analysis explored relationships between subject characteristics and exercise patterns via a self-completed questionnaire. Univariable and multivariable odds ratios were estimated using logistic regression. Multivariable models used backward stepwise variable selection. RESULTS: A total of 853 women agreed to participate and 529 women (62%) returned completed questionnaires. Of these, 369 (70%) and 258 (49%) engaged in a structured exercise program before pregnancy and in Trimester 3, respectively. Factors associated with engaging in regular structured exercise prior to pregnancy included: postsecondary education (OR = 1.50; 0.98, 2.30), no children (OR = 2.44; 1.56, 3.82), nonsmoker (OR = 1.84; 1.18, 2.88), and involvement in regular recreational activities (OR = 3.07; 1.81, 5.20). During pregnancy, all categories of activity decreased except walking, which increased by Trimester 3. Factors associated with quitting a regular structured exercise program by Trimester 3 were: having children (OR = 1.67; 1.05, 2.67), a prepregnancy BMI of 25 (OR = 1.79; 1.04, 3.13), and higher weight gain. IMPLICATIONS: Community programs that encourage active living should address these factors.  相似文献   

16.
17.
18.
Control and assessment of the uterus and cervix during pregnancy and labour   总被引:8,自引:0,他引:8  
Preterm labour and resultant preterm birth are the most important problems in perinatology. Countless efforts have failed to establish a single effective treatment of preterm labour, partly because the mechanisms regulating the uterus and cervix during pregnancy are not well understood. New knowledge is needed to inhibit early progression of labour (uterine contractility and cervical ripening), and adequate quantitative tools to evaluate the uterus and cervix during pregnancy are lacking. In this review, we outline studies showing that the uterus (myometrium) and cervix pass through a conditioning step in preparation for labour. This step is not easily identifiable with present methods to assess the uterus or cervix. In the uterus, this seemingly irreversible step consists of changes in the electrical properties to make muscle more excitable and responsive to produce forceful contractions. In the cervix, the step consists of softening of the connective tissue components. Progesterone appears to have a dominant role in controlling both the uterus and cervix, as antiprogestins induce early, preterm conditioning leading to preterm labour. Apparently, nitric oxide (NO) also controls conditioning of the uterus and cervix. In the uterus, NO, in concert with progesterone, inhibits uterine contractility. At term, NO production by the uterus and placenta are decreased and allow labour to progress. In contrast, NO in the cervix increases at the end of pregnancy and it may be the final pathway for stimulating cervical ripening by activation of metalloenzymes. The progress of labour can be assessed non-invasively using electromyographic (EMG) signals from the uterus (the driving force for contractility) recorded from the abdominal surface. Uterine EMG bursts detected in this manner characterize uterine contractile events during human and animal pregnancy. A low uterine EMG activity, measured transabdominally throughout most of pregnancy, rises dramatically during labour. EMG activity also increases substantially during preterm labour in humans and rats. This method may be used one day to predict impending preterm labour and identify control steps and treatments. A quantitative method also assesses the cervix, using an optical device which measures collagen fluorescence in the cervix. The collascope estimates cervical collagen content from a fluorescent signal generated when collagen cross-links are illuminated with excitation light of about 340 nm. The system has proved useful in rats and humans at various stages of pregnancy, and indicates that cervical softening occurs progressively in the last one-third of pregnancy. In rats, collascope readings correlate with resistance measurements made in the isolated cervix, which may help to assess cervical function during pregnancy, and indicate control and treatments.  相似文献   

19.

Purpose

The aim of the study was to assess perinatal outcome of pregnancy burdened with maternal addiction in comparison with an unselected population from a European transition country.

Materials and Methods

Data on pregnancies complicated by illicit drug abuse (n = 85) managed during a 10-year period (1997 - 2007) at Split University Hospital were analyzed. Data on the type of drug, course of gestation and labor, and on perinatal outcome were considered. Data on all non-dependence pregnancies recorded during the study period were used as a control group.

Results

During the study period, there were 85 dependence-complicated pregnancies (0.2%). Use of heroin alone during pregnancy was recorded in 51 women (50%), methadone alone in 6 (7%), and a combination of heroin and methadone in 9 (11%). Premature delivery was significantly more common in the group of pregnant addicts (21% vs. 6%); 49% of pregnant addicts were carriers of hepatitis C virus (HCV) and 14% of hepatitis B virus (HBV). Neonatal abstinence syndrome developed in 61 infants (7%) born to addicted mothers. There were 4 cases (4.6%) of early neonatal death; 7 neonates had 5-minute Apgar score ≤ 7 (8%); 29 neonates had low birth weight for age (33%); and 7 neonates had congenital anomalies (8%). The risk of various congenital anomalies was 3-fold in the group of children born to addicted mothers.

Conclusion

Addiction pregnancies present a small but high-risk group according to perinatal outcome. Appropriate obstetric and neonatal care can reduce the rate of complications in these pregnancies and improve perinatal outcome.  相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号