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901.
Urinary and plasma amines and amine metabolites were quantified in two individuals with Norrie disease resulting from a deletion in chromosomal region Xp11.3, recently reported to be associated with absence of the gene encoding monoamine oxidase (MAO)-A and nondetectable MAO-A activity in fibroblasts and MAO-B activity in platelets. Marked (four-to 100-fold) elevations in levels of urinary phenylethylamine, o-tyramine, and m-tyramine (which are preferential substrates for MAO-B) and marked reductions (90%) in levels of 3-methoxy-4-hydroxyphenylglycol (a deaminated metabolite of norepinephrine, a preferential substrate for MAO-A) in urine and plasma confirmed the presence of a systemic, functionally significant reduction in the activities of both MAO isozymes. The magnitude of these changes, which are equivalent to those found in subjects taking MAO-inhibiting antidepressants, suggests that early initiation of dietary and drug restrictions may be clinically important in these and other patients with X-chromosomal mutations involving MAO. These findings further support the proposition that the MAOA and MAOB genes are located in close proximity on the X chromosome. Negligible changes in the metabolites of dopamine and serotonin raise the possibility that other metabolic pathways are of importance for their production, that dietary or intestinal bacterial sources contribute substantially to the presence of these amine metabolites in urine, or both.  相似文献   
902.
Addition of concentrated rat Sertoli cell conditioned medium (rSCCM) to isolated Leydig cells from immature rats stimulated steroid production more than 13-fold within 4 h. LH-stimulated steroidogenesis was not enhanced by addition of rSCCM. The biological activity of the concentrated rSCCM was higher after incubation of Sertoli cells with FSH, whereas FSH alone did not stimulate steroid production. This effect of rSCCM was not due to inhibin, since highly purified 32 kDa rat inhibin, in doses equivalent to those present in rSCCM, had no effect on steroidogenesis during the 4 h incubation period. Furthermore, inhibin could be separated from the Leydig cell stimulating factor by anion-exchange chromatography. These results indicate a short-term paracrine control of Leydig cell steroidogenesis by Sertoli cell derived factors, which differ from inhibin.  相似文献   
903.
We describe a technique for the systematic inactivation of nonessential genes within the genome of a herpesvirus without the requirement for phenotypic selection. This technique is based on the insertion of an oligonucleotide containing translational stop codons at a random site within a large cloned viral DNA fragment. Mutant virus is then reconstituted by cotransfection with overlapping viral clones, together comprising the entire viral genome, as described previously (M. van Zijl, W. Quint, J. Briaire, T. de Rover, A. Gielkens, and A. Berns, J. Virol. 62:2191-2195, 1988). This technique was used to construct, in a single experiment, a set of 13 viable pseudorabies virus strains with oligonucleotide insertions within all known genes of the Us region except for the gp50 gene, which proved essential for virus growth in cell culture. The growth rate in porcine kidney cells of mutants of all nonessential Us genes was similar to that of the parental virus, with the exception of a mutant of the recently identified protein kinase gene.  相似文献   
904.
We have carefully examined the frequency of guanidine-resistant revertants in six different clonal pools of guanidine-dependent mutants of type 1 poliovirus. The mutation frequency was (6.5 +/- 6.3) x 10(-4) (with all amino acid substitutions occurring at position 227). The minimal corrected base substitution frequency per single nucleotide site in the codon for amino acid 227 was (2.1 +/- 1.9) x 10(-4).  相似文献   
905.
Selective IgG1 deficiency is a rare disease. We report a familial form of IgG1 deficiency, in which IgG1 was undetectable in a 5-yr-old girl with a history of asthma and respiratory tract infections. Her father had an IgG1 level that was one-third of the mean amount found in normal healthy controls. The defect in the proband was caused by a homozygous deletion of the structural gene for C gamma 1. A Southern blot analysis demonstrated that the maternal haplotype contained a deletion encompassing C gamma 1, C psi epsilon 1, C alpha 1, C psi gamma, and C gamma 2, whereas the deletion on the paternal haplotype was confined to the C gamma 1 gene. Neither of these deletions has previously been reported. IgG1 normally constitutes the dominant isotype for antibodies directed against protein Ag, including viral proteins. We have analyzed the immune response to a number of different protein and polysaccharide Ag in the patient and her parents. In the proband, antiviral antibodies were restricted to the IgG3 and IgG4 subclasses. However, the total amount of IgG directed against several viruses was below the concentration found in normal seropositive individuals. The father and the paternal grandfather, both with low serum IgG1 levels, also had asthma, thus indicating a possible causal relationship.  相似文献   
906.
The requirements for activation of the lytic machinery through CD2 of TCR gamma delta+/CD3+ cells were examined, by utilizing bispecific heteroconjugates containing anti-CD2 mAb cross-linked to anti-DNP. Contrary to the CD2 activation requirements in TCR alpha beta+/CD3+ cells, cytotoxic activity in TCR gamma delta+/CD3+ clones and TCR-/CD3- NK cell clones can be induced by heteroconjugates containing a single anti-CD2 (OKT11.1) mAb. Activation of TCR gamma delta+/CD3+ cells via CD2 is independent of heteroconjugates binding to CD16 (Fc gamma RIII), because heteroconjugates prepared from Fab fragments induced equal levels of lysis. Moreover, anti-CD16 mAb did not inhibit triggering via CD2 in TCR gamma delta+/CD3+ cells. In TCR-/CD3- NK cells, however, induction of cytotoxicity via CD2 is co-dependent on interplay with CD16. Anti-CD3 mAb blocked the anti-CD2 x anti-DNP heteroconjugate-induced cytotoxicity of TCR gamma delta+/CD3+ cells, indicating a functional linkage between CD2 and CD3 on these cells. We conclude that induction of lysis via CD2 shows qualitatively different activation requirements in TCR gamma delta+/CD3+, TCR alpha beta+/CD3+ CTL and TCR-/CD3- NK cells.  相似文献   
907.
Inclusion bodies were previously found in Papanicolaou smears of patients infected by the human papillomavirus (HPV). To ascertain their origin, 12 biopsies from patients with colposcopic evidence of papillomatous lesions were studied by cytology and electron microscopy. In several instances, koilocytotic atypias and electron-dense masses included within epithelial cells were observed. Some of these epithelial cells appeared to be surrounded by other cells in a sort of concentric arrangement. The electron-dense masses were composed of intermediate filaments, vacuoles and electron-dense material. They seemed to be dyskeratotic cells. They can be compared with apoptotic bodies and may be related to a disturbance of the involucrin expression caused by the HPV infection.  相似文献   
908.
Survival of patients with malignancy-associated effusions   总被引:1,自引:0,他引:1  
For a better understanding of the prognosis after the onset of a malignancy-associated effusion in patients known or subsequently shown to have cancer, survival time was compared with the findings and the date of the first cytologic diagnosis of an effusion. The number of patients studied was 254; 171 had a pleural and 83 a peritoneal effusion. The average survival time was 25.5 weeks, which was about equal for both sites of effusions. After two years, only 6% of all patients were alive. When the cytologic diagnosis of the effusion was "malignant," only 4% survived after two years; when the cytologic diagnosis was "suspicious for malignancy" and "nonmalignant," these figures were 5% and 7%, respectively. This indicates that a cytologic diagnosis of benign or nonmalignant is not a good indicator of a better prognosis in cancer patients for whom benign causes of the effusion have been excluded. There appeared to be a prognostic relationship between the length of the interval from the initial diagnosis of cancer to the time of examination of the first sample of the effusion: a longer interval was correlated with a better survival. When survival time was viewed in relation to therapy, patients whose pleural effusions were only treated by aspiration were found to have a particularly short average survival (13.9 weeks).  相似文献   
909.
910.
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