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41.
OBJECTIVE: To determine the effect of acute in vivo sildenafil citrate (VIAGRA) and in vitro 8-Bromo-cGMP treatments on semen parameters and sperm function. DESIGN: Prospective double-blind, placebo-controlled, crossover, two-period clinical investigation. SETTING: Healthy volunteers in an academic research environment. PATIENT(S): Twenty male volunteers with normal erectile function and normal electrocardiogram were recruited. INTERVENTION(S): In vivo: 50 mg of sildenafil citrate (VIAGRA) or placebo was administered p.o., and semen samples were collected 1 hour after administration of the test drug. In vitro: 8-Bromo-cGMP (20 microM; 60 minutes) was added to semen samples. MAIN OUTCOME MEASURE(S): Macroscopic and microscopic seminal parameters were measured and motility studies performed. Various acrosome reaction studies and sperm-zona pellucida binding studies were also done. RESULT(S): Either sildenafil citrate (VIAGRA) or 8-Bromo-cGMP treatments had no effect on both macroscopic and microscopic seminal parameters as well as the acrosome reaction. Sperm-zona pellucida binding results were however increased to 148.75% and 134%, respectively, by these treatments. Various kinematical parameters increased after treatment with the most significant increase detected in the population of rapid cells. CONCLUSION(S): VIAGRA can be used successfully to enhance sperm motility and binding to the oocyte especially during fertility treatments.  相似文献   
42.
Metachromatic leukodystrophy (MLD) is a lysosomal lipid storage disease caused by arylsulfatase A deficiency. In MLD patients the sphingolipid sulfatide increasingly accumulates leading to progressive demyelination. We have analysed arylsulfatase A-deficient mice, a MLD mouse model, and we show that accumulation of sulfatide is not restricted to the lysosomal compartment but also occurs in myelin itself. Although, this sulfatide storage did not affect the overall composition of most myelin proteins, it specifically caused a severe reduction of MAL. This demonstrates a regulatory link between sulfatide accumulation and MAL expression and indicates the existence of regulatory mechanisms between lipid and myelin protein synthesis in oligodendrocytes. In addition, in cultured renal epithelial cells, sulfatide accumulation diverts MAL to the late endosomal/lysosomal compartment and thus also affects the intracellular distribution of MAL. The specific reduction and mistargeting of MAL protein as a reaction to sulfatide overload may contribute to the pathogenic mechanisms in metachromatic leukodystrophy.  相似文献   
43.
OBJECTIVE: To evaluate the possible relationships between sperm morphology, acrosome responsiveness to solubilized human zona pellucida, and sperm-zona binding potential among [1] consecutive andrology referrals and [2] randomly selected in vitro fertilization (IVF) cases. DESIGN: Prospective analytical study. SETTING: Academic training hospital.Randomly selected couples consulting for infertility. INTERVENTION(S): Acrosome reaction response to solubilized human zona pellucida was recorded. MAIN OUTCOME MEASURE(S): We determined the difference in the percentage of sperm that acrosome reacted after exposure to solubilized zona pellucida and spontaneous acrosome reaction. The results were expressed as percentage zona induced acrosome reaction (ZIAR). RESULT(S): Data were analyzed using correlation coefficients (r) and receiver operator characteristics (ROC curve analyses). The ROC curve analyses indicated ZIAR to be a sensitive indicator for fertilization failure during IVF therapy, with sensitivity and specificity of 81% and 75%, respectively. For andrology referrals, a positive and statistically significant correlation existed between ZIAR data and sperm morphology (r = 0.65) and sperm-zona binding (r = 0.57). CONCLUSION(S): ZIAR results provide further information regarding dysfunctional sperm and can be used as an additional diagnostic test. Our results predicted fertilization failure during IVF treatment.  相似文献   
44.
45.
Late-infantile neuronal ceroid lipofuscinosis (LINCL) is a progressive neurodegenerative disorder caused by the deficiency of lysosomal tripeptidyl peptidase I (TPP-I) encoded by the CLN2 gene. We report the first case of early prenatal diagnosis of LINCL by combined enzyme and mutation analysis. TPP-I activity in chorionic villi (CV) was less than 2% of the mean normal control level and g.1946A > G and g.3670C > T mutations were demonstrated, as in the two previously affected children. After termination of pregnancy, TPP-I deficiency was confirmed in cultured CV cells and in the fetal skin fibroblasts. The expression of unequivocal TPP-I deficiency in CV demonstrates that enzyme assay is a reliable option for prenatal diagnosis of LINCL.  相似文献   
46.
In the present review, an integrated approach to craving and addiction is discussed, which is based on recent insights from psychology and neuropsychopharmacology. An integrated model explains craving and relapse in humans by the psychological mechanism of "attentional bias" and provides neuropsychopharmacological mechanisms for this bias. According to this model, cognitive processes mediate between drug stimulus and the subject's response to this stimulus and subsequent behavioral response (e.g., drug use, relapse). According to the model, a conditioned drug stimulus produces an increase in dopamine levels in the corticostriatal circuit, in particular the anterior cingulate gyrus, amygdala, and nucleus accumbens, which in turn serves to draw the subject's attention towards a perceived drug stimulus. This process results in motor preparation and a hyperattentive state towards drug-related stimuli that, ultimately, promotes further craving and relapse. Evidence for this attentional bias hypothesis is reviewed from both the psychopharmacological and the neuroanatomical viewpoints. The attentional bias hypothesis raises several suggestions for clinical approaches and further research.  相似文献   
47.
Sperm chromatin packaging as an indicator of in-vitro fertilization rates   总被引:6,自引:0,他引:6  
The development of a sequential diagnostic schedule for patients consulting for infertility disturbances would be an ideal method of approach for clinicians in the absence of an aetiological or pathophysiological diagnosis. Since sperm morphology recorded by strict criteria has often been correlated with fertilization failure, the present study aimed to evaluate the relationship between normal morphology as well as in-vitro fertilization (IVF) rates, with chromatin staining among fertile and subfertile men. Two semen smears were prepared from each specimen obtained from 72 men to record normal morphology and chromatin packaging as recorded by chromomycin A(3) (CMA(3)) staining. Following the semen analyses, the 72 men were divided into the two morphological groups, namely <4% and >4% normal forms. Significantly different percentages of CMA(3) staining (mean +/- SE) were recorded between the two morphological groups, namely 65.9% +/- 3.5 and 44.5% +/- 1.7 (P +/- 0.001). A highly negative significant correlation existed between percentage of normal morphology as recorded by strict criteria and CMA(3) staining. A highly significant and positive correlation was recorded for normal morphology and IVF rates (r +/- 0.45, P +/- 0.0001). A significant negative correlation (r +/- -0.51, P +/- 0.0001) existed between CMA(3) values and IVF rates. The discriminating power of nuclear maturity, as recorded by CMA(3) staining, to identify abnormal morphology values and poor IVF rates was calculated with receiver operator characteristic (ROC) analyses. The areas under the ROC curves were 0.86 for sperm morphology and 0. 74 for IVF rates. The calculated threshold values for CMA(3) staining to distinguish between morphology groups were 48 and 50% for IVF. Chromatin packaging assessment is a valuable addition to the sequential diagnostic programme in an assisted reproductive arena.  相似文献   
48.
The impact of late muscular injury after radiotherapy on the well being of patients, particularly those treated at a relatively young age, is often underestimated. To extend the present knowledge, a detailed comparative study of the radiation response of skeletal muscles was performed. The hind limb of rats was irradiated at the age of 30-60 days (young), at approximately 200 days (adult) or at the age of >360 days (old), with single doses ranging from 15-60 Gy. Muscular wet weight, volume and tibia length was followed up to 12 months post-treatment. Radiation treatment resulted in muscular wasting, which was more severe at higher doses. The radiation response depended strongly on the age of the animal at the time of treatment. Radiation induced muscle wasting and stunted tibia growth were more prominent in young animals than in adult or in old rats. ED50 values based on normalized wet weight were 12.5 (11.5-13.6) Gy for young animals and 22.5 (21.8-23.3) Gy for adult animals. The gastrocnemius muscle of young animals appears to be more radiosensitive than the gastrocnemius muscle of adult or old animals. Furthermore, in young animals, severe wasting of the muscles may already occur after relative low radiation doses (single dose of 15 Gy).  相似文献   
49.
Neural arch dysplasia of the cervical 4 vertebrae is a rare occurrence. The authors present a case with dysplasia of cervical bodies and posterior arch elements at multiple levels. The embryogenesis of these anomalies is discussed.  相似文献   
50.
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