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91.
Gabaculine, a conformationally restricted analogue of GABA, is (i) a moderately potent inhibitor (IC50 69 μM) of the sodium-dependent uptake of GABA in rat brain slices, (ii) ineffective at 100 μM as an inhibitor of the sodium-independent binding of GABA to membranes from rat brain, (iii) a relatively weak inhibitor (IC50 > 1 mM) of glutamate decarboxylase activity in tracts of rat brain, and (iv) a very potent inhibitor (IC50 3 μM) of the transamination of GABA catalyzed by extracts of rat brain mitochondria. Inhibition of transamination is time-dependent and follows pseudo-first order kinetics, which is consistent with gabaculine acting as a catalytic inhibitor at the active site. 相似文献
92.
Hydrosalpinges adversely affect markers of endometrial receptivity 总被引:22,自引:10,他引:22
Meyer WR; Castelbaum AJ; Somkuti S; Sagoskin AW; Doyle M; Harris JE; Lessey BA 《Human reproduction (Oxford, England)》1997,12(7):1393-1398
While in-vitro fertilization (IVF) was initially developed in women with
tubal factor infertility, recent clinical studies have suggested that the
presence of hydrosalpinges lowers implantation and pregnancy rates. We
postulated that these hydrosalpinges cause impaired endometrial
receptivity. A total of 103 women with hydrosalpinges were prospectively
evaluated, and compared with 55 infertile and 44 fertile controls. All
women had endometrial biopsies during the window of implantation, analysed
by conventional histological criteria, and also stained for three integrin
markers of endometrial receptivity (alpha1beta1, alpha4beta1 and alpha
vbeta3). Women with hydrosalpinges (cases) expressed significantly less of
the alpha vbeta3 integrin compared with controls. There was no difference
in expression of alpha1beta1 or alpha4beta1 among groups. A significantly
greater number of cases had out of phase histology and missing alpha vbeta3
(type I defects) and absent integrin expression despite normal histological
maturation (type II) defects, compared with controls. Of 20 women with
impaired endometrial receptivity who were also biopsied after hydrosalpinx
surgery, 70% demonstrated increased alpha vbeta3 expression. Seventy-seven
percent of type I and 57% of type II defects were corrected
postoperatively. Using markers of endometrial receptivity, this study
demonstrates that inflammatory hydrosalpinges have an adverse effect on
endometrial receptivity, which in some cases may be overcome by surgical
treatment of the hydrosalpinx.
相似文献
93.
采用生物素结合的葡聚糖胺顺行示踪法研究了大鼠视皮质主要胼胝体投射区即17/18a交界区胼胝体轴突的生后发育和形态。在生后5天时,此交界区胼胝体轴突从白质向灰质Ⅰ层垂直生长,在灰质内仅有极少量的侧支抽芽。至生后13天时,皮质Ⅰ层最先出现致密的由胼胝体轴突终支组成的终末丛。到生后17天时,类似的终末丛也见于皮质Ⅱ/Ⅲ,Ⅴ和Ⅵ层,这种分布型式与成年大鼠者相似。以上结果表明,绝大部分胼胝体轴突首先生长到达Ⅰ层并先在Ⅰ层发出终支,然后再在其它皮质层发出侧支及终支,因而提示皮质Ⅰ层在胼胝体联系的生后发育中可能发挥重要作用。 相似文献
94.
Seventy-four mothers and 41 fathers and their 6 to 13 year old sons with attention-deficit hyperactivity disorder (ADHD) watched videos of child ADHD symptoms, compliance, and noncompliance. Participants were told either that the child was receiving medication, behavioral treatment, a combination of the two, or was not receiving treatment and were asked to rate the cause of the behavior. Parents attributed less control but greater stability to positive child behaviors when the child was receiving medication. However, for negative behaviors, medication increased attributions of control but diminished stability. With behavior management. compliance was seen as more external and stable and noncompliance as more controllable but less stable. For all treatments, boys reported increased control over ADHD symptoms and noncompliance. The implications of these treatment-related attributions for parenting and children's self-perceptions are discussed. 相似文献
95.
Lawrence S. Webb Bernard B. Keele Jr. Richard B. Johnston Jr. 《Infection and immunity》1974,9(6):1051-1056
During the process of phagocytosis, human leukocytes emit a burst of luminescence which can be measured in a liquid scintillation spectrometer. The enzyme superoxide dismutase, which removes superoxide anions (O(2.)), inhibited this chemiluminescence by 70% at a concentration of 100 mug/ml. The enzyme did not inhibit phagocytosis. These results support other studies indicating that O(2.) is elaborated by phagocytizing leukocytes. They also indicate that O(2.) plays a major role in phagocytosis-associated chemiluminescence, though not necessarily as the luminescing agent. Catalase and benzoate inhibited the chemiluminescence of phagocytosis to a slight extent, suggesting that hydrogen peroxide and hydroxyl radical, respectively, might also be involved in this phenomenon. The relationship between the mediators of chemiluminescence and those responsible for phagocytic bactericidal activity remains to be defined. 相似文献
96.
Synergy between the genes for butyrylcholinesterase K variant and apolipoprotein E4 in late-onset confirmed Alzheimer's disease 总被引:5,自引:2,他引:5
The allelic frequency of the gene for the K variant of
butyrylcholinesterase (BCHE-K) was 0.17 in 74 subjects with late-onset (age
> 65 years) histopathologically diagnosed Alzheimer's disease (AD),
which was higher than the frequencies in 104 elderly control subjects
(0.09), in 14 early-onset cases of confirmed AD (0.07) and in 29 confirmed
cases of other dementia (0.10). The association of BCHE-K with late-onset
AD was limited to carriers of the epsilon 4 allele of the apolipoprotein E
gene (APOE), among whom the presence of BCHE-K gave an odds ratio of
confirmed late-onset AD of 6.9 (95% C.I. 1.65-29) in subjects > 65 years
and of 12.8 (1.9-86) in subjects > 75 years. In APOE epsilon 4 carriers
over 75 years, only 1/22 controls, compared with 10/24 confirmed late-onset
AD cases, had BCHE-K. We suggest that BCHE-K, or a nearby gene on
chromosome 3, acts in synergy with APOE epsilon 4 as a susceptibility gene
for late-onset AD.
相似文献
97.
Optimization of a method for deactivation of platelet-activating factor:acetylhydrolase in serum for use in in-vitro fertilization culture media 总被引:1,自引:0,他引:1
Embryos produced by in-vitro fertilization (IVF) may produce less
platelet-activating factor (PAF) than is optimal for development. It was
previously shown that supplementation of culture media with PAF results in
a significant increase in pregnancy rate. Human embryos are often cultured
in media supplemented with serum containing the enzyme PAF:acetylhydrolase
(PAF:AH; EC 3.1.1.47), which hydrolyses PAF to its inactive form, lyso-PAF.
Thus, effective supplementation of media with PAF requires inactivation of
this enzyme. In this study we examine the efficacy of the methods of PAF:AH
deactivation used for PAF supplementation of IVF culture medium. When the
effectiveness of a commonly used acid treatment protocol (pH 3.0 at room
temperature for 5 min) was examined, it was found that it was not
completely effective for the majority of sera. When synthetic PAF was added
to 18 serum samples which had been acid treated, five had 90-100% of the
original PAF remaining after 24 h (showing that the acid treatment was
effective), eight had from 10-90% of the original PAF remaining after 24 h,
and five samples had 0-10%. The extent to which PAF:AH was susceptible to
deactivation was not associated with the activity in the serum prior to
treatment, the serum oestradiol concentration, or the cause of infertility.
The period of acidification and the incubation temperature were assessed to
develop a new acid-treatment protocol (20 min acid treatment at 37 degrees
C) which was able to deactivate PAF:AH effectively in all sera (53/53)
examined. A trial was performed to assess the effect of acid treatment of
serum for 5 min at room temperature compared with the new protocol (20 min
at 37 degrees C) on IVF outcome, following PAF supplementation of IVF
culture medium. Oocyte recovery, fertilization and embryo development rates
were equivalent for both groups and approximately equal numbers of embryos
were transferred or cryopreserved. Pregnancy rates were not significantly
different (14.6 versus 20.0%) for the two treatments, with a trend towards
a higher pregnancy rate with the new acid- treatment protocol. The results
show that this new procedure for acid treatment of serum in combination
with PAF supplementation does not have detrimental effects on embryos and
their pregnancy outcome and is therefore suitable for use in IVF.
相似文献
98.
Positional cloning of the gene for X-linked retinitis pigmentosa 3: homology with the guanine-nucleotide-exchange factor RCC1 总被引:6,自引:7,他引:6
Roepman R; van Duijnhoven G; Rosenberg T; Pinckers AJ; Bleeker-Wagemakers LM; Bergen AA; Post J; Beck A; Reinhardt R; Ropers HH; Cremers FP; Berger W 《Human molecular genetics》1996,5(7):1035-1041
The gene for retinitis pigmentosa 3 (RP3), the most frequent form of X-
linked RP (XLRP), has been mapped previously to a chromosome interval of
less than 1000 kbp between the DXS1110 marker and the OTC locus at
Xp21.1-p11.4. Employing a novel technique, YAC Representation Hybridization
(YRH)', we have recently identified a small XLRP associated microdeletion
in this interval, as well as several putative exons including the 3' end of
a gene that was truncated by the deletion. cDNA library screening and
sequencing of a cosmid centromeric to the deletion has now enabled us to
identify numerous additional exons and to detect several point mutations in
patients with XLRP. The predicted gene product shows homology to RCC1, the
guanine-nucleotide- exchange factor (GEF) of the Ras-like GTPase Ran. Our
findings suggest that we have cloned the long-sought RP3 gene, and that it
may encode the GEF of a retina-specific GTP-binding protein.
相似文献
99.
Immunochemical analysis of immune response to Chlamydia trachomatis in Reiter''s syndrome and nonspecific urethritis. 总被引:6,自引:0,他引:6 下载免费PDF全文
R D Inman M E Johnston B Chiu J Falk M Petric 《Clinical and experimental immunology》1987,69(2):246-254
Chlamydia trachomatis (Ct) has been proposed as a causative agent in Reiter's syndrome (RS) when an infection occurs in a susceptible host. To assess whether this susceptibility is reflected in a characteristic humoral immune response we compared patients with complicated (RS) and uncomplicated courses of nonspecific urethritis (NSU). Geometric mean titres of antibodies to C. trachomatis by immunofluorescence were 89.6 for RS, 80.0 for NSU and 16.0 for normals. 125I-Protein A probing of immunoblotted antigens of C. trachomatis revealed no band unique to RS. 125I-anti-IgA probing of immunoblots demonstrated reactivity with the 59,000 dalton antigen in 11/11 RS and 2/6 NSU. The major outer membrane protein of C. trachomatis (40,000 daltons) bound immunoglobulin nonspecifically. There was no clearly differentiating feature between HLA-B27-positive and B27-negative RS. One sequentially studied patient revealed an augmentation in synovial fluid IgA reactivity during the course of disease. No pattern of humoral immune response to C. trachomatis could be regarded as specific for RS nor for HLA B27-positivity. The study did not identify a Reiter's-specific antigen in C. trachomatis but demonstrates the usefulness of applying blotting techniques to population studies of HLA modulation of immune response to infectious agents. 相似文献
100.
The t(X;1)(p11.2;q21.2) translocation in papillary renal cell carcinoma fuses a novel gene PRCC to the TFE3 transcription factor gene 总被引:4,自引:2,他引:4