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21.
High-resolution cytogenetic analysis of a large number of women with premature ovarian failure (POF) identified six patients carrying different Xq chromosome rearrangements. The patients (one familial and five sporadic cases) were negative for Turner's stigmata and experienced a variable onset of menopause. Microsatellite analysis and fluorescent in situ hybridization (FISH) were used to define the origin and precise extension of the Xq anomalies. All of the patients had a Xq chromosome deletion as the common chromosomal abnormality, which was the only event in three cases and was associated with partial Xp or 9p trisomies in the remaining three. Two of the Xq chromosome deletions were terminal with breakpoints at Xq26.2 and Xq21.2, and one interstitial with breakpoints at Xq23 and Xq28. In all three cases, the del(X)s retained Xp and Xq specific telomeric sequences. One patient carries a psu dic(X) with the deletion at Xq22.2 or Xq22.3; the other two [carrying (X;X) and (X;9) unbalanced translocations, respectively] showed terminal deletions with the breakpoint at Xq22 within the DIAPH2 gene. Furthermore, the rearranged X chromosomes were almost totally inactivated, and the extent of the Xq deletions did not correlate with the timing of POF. In agreement with previous results, these findings suggest that the deletion of a restricted Xq region may be responsible for the POF phenotype. Our analysis indicates that this region extends from approximately Xq26.2 (between markers DXS8074 and HIGMI) to Xq28 (between markers DXS 1113 and ALD) and covers approximately 22 Mb of DNA. These data may provide a starting point for the identification of the gene(s) responsible for ovarian development and folliculogenesis.  相似文献   
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The depth of two‐photon fluorescence imaging in turbid media can be significantly enhanced by the use of the here described fluorescence detection method that allows to efficiently collect scattered fluorescence photons from a wide area of the turbid sample. By using this detector we were able to perform imaging of turbid samples, simulating brain tissue, at depths up to 3 mm, where the two‐photon induced fluorescence signal is too weak to be detected by means used in conventional two‐photon microscopy. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   
24.
Rhythms in the ovulatory cycle. 2nd: LH, FSH, estradiol and progesterone   总被引:3,自引:0,他引:3  
The circadian profiles of LH, FSH, estradiol and progesterone were compared in a homogeneous group of 15 young normally cycling women, at 4 well characterized times of the menstrual cycle: early follicular (EF), late follicular (LF), early luteal (EL) and late luteal (LL) stages. The circatrigintan profiles of the same hormones were also evaluated. Population-mean cosinor analysis failed to demonstrate a circadian periodicity of LH in any of the 4 stages of the menstrual cycle; a circadian rhythm for FSH was present only in the 2 luteal phases (EL, LL); the same type of rhythmicity was present for estradiol only in the late luteal stage; on the contrary, a highly significant circadian rhythm of progesterone was present in each of the 4 menstrual stages considered (EF, LF, EL and LL). Population-mean cosinor analysis showed a highly significant circatrigintan periodicity of LH and FSH with the acrophases respectively between -109 degrees and -181 degrees and between -74 degrees and -125 degrees. Circatrigintan rhythmicity was also present for estradiol (acrophases between -161 degrees and -245 degrees) and progesterone (acrophases between -246 degrees and -296 degrees).  相似文献   
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Activity of the enzyme choline acetyltransferase (CAT), which mediates the synthesis of the neurotransmitter, acetylcholine, was increased up to 20- fold in spinal cord (SC) cells grown in culture with muscle cells for 2 wk. This increase was directly related to the duration of co-culture as well as to the cell density of both the SC and muscle involved and was not affected by the presence of the acetylcholine receptor blocking agent, α-bungarotoxin. Glutamic acid decarboxylase (GAD) activity was often markedly decreased in SC-muscle cultures while the activities of acetylcholinesterase and several other enzymes were little changed. Increased CAT activity was also observed when SC cultures were maintained in medium which had been conditioned by muscle cells or by undifferentiated cells from embryonic muscle. Muscle-conditioned medium (CM) did not affect the activities of SC cell GAD or acetylcholinesterase. Dilution or concentration of the CM directly affected its ability to increase SC CAT activity , as did the duration and timing of exposure of the SC cells to the CM. The medium could be conditioned by muscle cells in the presence or absence of serum, and remained effective after dialysis or heating to 58 degrees C. Membrane filtration data were consistent with the conclusion that the active material(s) in CM had a molecular weight in excess of 50,000 daltons. We conclude that large molecular weight material that is released by muscle cells is capable of producing a specific increase in CAT activity of SC cells.  相似文献   
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Little is known about the effects of cholesterol-lowering agents in hypercholesterolemic patients with primary biliary cirrhosis (PBC). The aim of this study was to compare the changes induced by simvastatin and ursodeoxycholic acid (UDCA) on cholesterol metabolism in patients with PBC and preserved liver function. Six patients with PBC were administered simvastatin (40 mg/day) for 30 days and, after a washout period of 30 days, ursodeoxycholic acid (600 mg/day) for 30 days. Serum levels of lathosterol, campesterol, 7 alpha-hydroxycholesterol, and 27-hydroxycholesterol were measured by gas chromatography-mass spectrometry. During simvastatin administration, reduction of cholesterol levels (34% in 30 days) was paralleled by the decrease of lathosterol (55%), whereas concentrations of campesterol and of the two hydroxysterols were not substantially modified. During ursodeoxycholic acid administration, a trend toward a decrease of serum cholesterol concentrations was observed after only one year of treatment, and these changes were paralleled by the decrease of campesterol serum levels. Both simvastatin and UDCA were well tolerated, and a reduction of serum liver enzyme levels occurred with the latter.Simvastatin proved to be safe and effective in reducing serum cholesterol levels in patients with PBC by an inhibitory effect on cholesterol synthesis occurring within 24 h. --Del Puppo, M., M. Galli Kienle, A. Crosignani, M. L. Petroni, B. Amati, M. Zuin, and M. Podda. Cholesterol metabolism in primary biliary cirrhosis during simvastatin and UDCA administration. J. Lipid Res. 2001. 42: 437--441.  相似文献   
27.
The circadian profiles of cortisol and dehydroepiandrosterone sulphate (DHEA-S) were analyzed in a homogeneous group of 15 young normally cycling women, at 4 times of the menstrual cycle: early follicular (EF), late follicular (LF), early luteal (EL) and late luteal (LL) stages. The circatrigintan variations of the same hormones were also evaluated. Population-mean cosinor analysis allowed the demonstration of a highly significant circadian periodicity for both variables in any of the 4 stages of the menstrual cycle; on the other hand, the same computation failed to demonstrate a significant circatrigintan periodicity. In each of the stages considered, the circadian acrophase of DHEA-S was delayed in comparison to that of cortisol, being located in the early afternoon hours. The demonstration of a clear-cut circadian oscillation in serum DHEA-S prompts studies on possible chrono-abnormalities of the steroid production in women with hyperandrogenic diseases.  相似文献   
28.
Prenatal maternal psychological distress increases risk for adverse infant outcomes. However, the biological mechanisms underlying this association remain unclear. Prenatal stress can impact fetal epigenetic regulation that could underlie changes in infant stress responses. It has been suggested that maternal glucocorticoids may mediate this epigenetic effect. We examined this hypothesis by determining the impact of maternal cortisol and depressive symptoms during pregnancy on infant NR3C1 and BDNF DNA methylation. Fifty-seven pregnant women were recruited during the second or third trimester. Participants self-reported depressive symptoms and salivary cortisol samples were collected diurnally and in response to a stressor. Buccal swabs for DNA extraction and DNA methylation analysis were collected from each infant at 2 months of age, and mothers were assessed for postnatal depressive symptoms. Prenatal depressive symptoms significantly predicted increased NR3C1 1F DNA methylation in male infants (β = 2.147, P = 0.044). Prenatal depressive symptoms also significantly predicted decreased BDNF IV DNA methylation in both male and female infants (β = −3.244, P = 0.013). No measure of maternal cortisol during pregnancy predicted infant NR3C1 1F or BDNF promoter IV DNA methylation. Our findings highlight the susceptibility of males to changes in NR3C1 DNA methylation and present novel evidence for altered BDNF IV DNA methylation in response to maternal depression during pregnancy. The lack of association between maternal cortisol and infant DNA methylation suggests that effects of maternal depression may not be mediated directly by glucocorticoids. Future studies should consider other potential mediating mechanisms in the link between maternal mood and infant outcomes.  相似文献   
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An important issue in epidemiology, often exploratory, is to compare the mortality of a certain cohort, exposed to some dangerous conditions, to that of a reference population. The main statistical tool to study relative mortality has long been the subject-years method. We propose a Bayesian version of the subject-years method, particularly suited to analyse the mortality of small cohorts. In particular, we employ the Bayes factor in order to test whether the mortality of a cohort exceeds that of a reference population. The methodology is applied to an occupational epidemiology study. The results are compared to those obtained from the classical one-sided tests on the same data.  相似文献   
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