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991.
The familial occurrence of essential tremor combined with (congenital) nystagmus, duodenal ulceration and a narcolepsy-like sleep disturbance caused by an autosomal dominant gene with high penetrance and fairly uniform expressivity is reported in a family of Swedish-Finnish ancestry. Twelve of 17 affected family members had essential tremor which began between 30-40 years of age and which could be controlled temporarily by alcohol; this resulted in alcoholism in several affected individuals. The most severly affected persons showed cerebellar signs which may reflect a possible pathogenetic relationship of the syndrome to the genetic cerebellar atrophies. Nystagmus, observed in 12 of 17 affected family members (eight of whom were also affected with tremor) usually was congenital and accompanied by refractive errors. Duodenal ulcers occurred almost exclusively in individuals with the neurological syndrome, and preceded its onset in some cases. The ulcer disease therefore seems to be a component manifestation of the syndrome and is interpreted as a pleiotropic effect of the gene which also causes the nystagmus, tremor and sleep disturbance.  相似文献   
992.
Toluene diisocyanate (TDI) sensitivity accompanied by nonspecific bronchial hyperresponsiveness occurs in approximately 5% of occupationally exposed workers. We report the case of a 32-yr-old worker followed longitudinally after removal from isocyanate exposure. TDI reactivity was lost 11 mo after removal from exposure and nonspecific bronchial hyperresponsiveness resolved after 17 mo. Bronchial reactivity to radishes (Raphanus sativus), which developed concurrently with TDI reactivity, was lost 2 yr later. Immunopharmacologic results show that the worker's initial decreased ability of lymphocytes to produce cyclic AMP returned to near normal after 2 yr. IgE antibodies to a human serum albumin tolyl monoisocyanate conjugate were still present at this time.  相似文献   
993.
Steroid hormones regulate sexual behavior primarily by slow, genomically mediated effects. These effects are realized, in part, by enhancing the processing of relevant sensory stimuli, altering the synthesis, release, and/or receptors for neurotransmitters in integrative areas, and increasing the responsiveness of appropriate motor outputs. Dopamine has facilitative effects on sexual motivation, copulatory proficiency, and genital reflexes. Dopamine in the nigrostriatal tract influences motor activity; in the mesolimbic tract it activates numerous motivated behaviors, including copulation; in the medial preoptic area (MPOA) it controls genital reflexes, copulatory patterns, and specifically sexual motivation. Testosterone increases nitric oxide synthase in the MPOA; nitric oxide increases basal and female-stimulated dopamine release, which in turn facilitates copulation and genital reflexes. Serotonin (5-HT) is primarily inhibitory, although stimulation of 5-HT(2C) receptors increases erections and inhibits ejaculation, whereas stimulation of 5-HT(1A) receptors has the opposite effects: facilitation of ejaculation and, in some circumstances, inhibition of erection. 5-HT is released in the anterior lateral hypothalamus at the time of ejaculation. Microinjections of selective serotonin reuptake inhibitors there delay the onset of copulation and delay ejaculation after copulation begins. One means for this inhibition is a decrease in dopamine release in the mesolimbic tract.  相似文献   
994.
α-Amino-iso-butyrate (AIB) inhibits long-term, protein synthesis-dependent memory formation by reducing labelled leucine uptake in vivo without affecting leucine incorporation into protein. Unlike the antibiotic cycloheximide, AIB does not block long-term memory formation through inhibition of protein synthesis per se. The behavioural effect of AIB is restricted to times of administration between 5 min before and 5 min after learning a single trial passive avoidance task by day-old chickens. It is concluded that (1) AIB competes with normal amino acids for uptake into cells, and (2) the uptake of amino acids for protein synthesis specific to long-term memory formation takes place in the first few minutes following learning.  相似文献   
995.
996.
We studied 174 strains of the genus Bacillus for cross-reacting antigens to the capsular polysaccharides of groups A and C meningococcus, types I and III pneumococcus, and Haemophilus influenzae type b. Cross-reactions were detected by immunodiffusion in agarose gel by using type-specific antisera and confirmed by absorption and inhibition experiments. Of 20 Bacillus pumilis strains, six had an antigen cross-reacting with group A meningococcal polysaccharide. Other cross-reactions included one strain of B. pumilis with H. influenzae type b, one of B. cereus var. mycoides with pneumococcus type III, and one of B. alvei with both type b and SIII polysaccharides. These cross-reacting antigens are polysaccharides of vegetative cells and may be extracellular in location. Because these bacilli have antigens cross-reacting with the virulence factors of pyogenic bacteria, they may, as normal flora, be an antigenic stimulus for "natural" serum anti-capsular antibodies to the type b Haemophilus and group A meningococcus polysaccharides.  相似文献   
997.
Radiologic evaluation of the skeleton and scanning electron microscopic studies of the teeth were performed on an infant boy with a lethal osteogenesis imperfecta (OI) syndrome who died at 10 mo of pneumonia. The skeletal findings included ribs that were focally expanded by fracture calluses, flat vertebral bodies, and wide limb bones. On fractured tooth surfaces, the enamel and dentin were normal as was the dentin calcification front. Although microscopic abnormalities have been noted in teeth from previously reported infants with lethal OI, a few studies also report infants with normal teeth. These differences in dental findings may indicate heterogeneity in OI lethal in infancy. Results of our study indicate that, until the primary biochemical defects in the OI syndromes are elucidated, examination of teeth from other infants with lethal OI and detailed evaluation of other clinical and skeletal features will aid in delineating heterogeneity and variation in expression in lethal OI.  相似文献   
998.
Human KB cell lines resistant to high levels of colchicine were isolated by several successive single-step selections. Most of these selection steps resulted in cross-resistance to vincristine, vinblastine, adriamycin, actinomycin D, and puromycin; however, at the highest levels of colchicine resistance, increased cross-resistance to other drugs was not observed. There was no major change in protein synthesis or alteration in protein phosphorylation or [14C]glucosamine labeling patterns accompanying the development of multiple drug resistance as measured by analysis of metabolically labeled proteins on SDS gels. Cell-cell hybridization experiments showed that the colchicine-resistant and multiple drug-resistant phenotypes were incompletely dominant. In addition, colchicine resistance was found to segregate independently from resistance to other drugs in one somatic cell hybrid, suggesting that complex genetic loci are involved in the development of the multiple drug-resistant phenotype. These mutants should be useful for the study of the clinically important problem of multiple drug resistance in human cancer.  相似文献   
999.
The purpose of this study was to compare estimates of body composition in two ethnic groups, 31 black and 38 white girls 10 through 16 years of age, to establish accurate and precise laboratory standards for field measures of body composition in the NHLBI Growth and Health Study HC 55025. The dual energy X-ray absorptiometry (DXA) measures of fat free mass (FFM) and % body fat (%BF) were made using Hologic QDR-1000/W. Corresponding values of FFM and %BF from underwater weighing (UWW) were determined using the two-component model of Siri, and these were corrected using the model of Lohman for white girls only. In the comparison of the different models and methods, the two-component model overestimated FFM compared to estimates from DXA for black girls, as did the corrected Lohman model for white girls. The two-component model significantly overestimated %BF in both white and black girls compared to corresponding estimates from DXA. The ratio of bone mineral content (BMC)/FFM affected the degree of %BF differences in black girls but not in white girls. Also, as the density of FFM increased or approached adult status in black girls (BMC/FFM increased), differences between the two-component model and estimates from DXA decreased. In both groups of girls, the relationship of %BF from UWW and DXA are a function of the level of body fatness. DXA values of %BF are greater than those from UWW under about 24% body fat, but the converse occurs above 25% body fat. The inability of UWW using the two-component model to account for the body composition in these girls can be corrected in part by measuring the variables for a multicomponent model or more easily by using DXA estimates of body composition. © 1994 Wiley-Liss, Inc.  相似文献   
1000.
The use of elongated prophase and prometaphase chromosome preparations has allowed detection of an insertion of a small segment of 3q into 11q in a kindred with 4 balanced carriers and 8 unbalanced offspring. Those with partial 3q deletion have a true multiple congenital anomalies/mental retardation (MCA/MR) syndrome with an appearance suggestive of the Schwartz-Jampel syndrome.  相似文献   
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