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1.
Eleven males with XLP were evaluated for EBV-specific antibodies during periods of 2 to 7 yr. Variable responses to EBV-specific antigens were found. All 11 patients had subnormal anti-EBNA titers, which probably reflected a T cell deficiency. The patients showed four different patterns in their anti-VCA response: 1) two boys who had experienced malignant lymphoma mounted no antibodies at all; 2) two patients showed intermittent anti-VCA titers; 3) four males had persistently elevated anti-VCA titers; and 4) three patients showed normal anti-VCA titers. ADCC against EBV-infected cells was abnormally low in six patients and was elevated in two patients given gamma-globulin. ADCC titers did not correlate with anti-VCA titers. However, most patients with XLP failed to effect regression of autologous EBV-infected lymphoblastoid cell lines, indicating a deficiency in long-lived T cell-mediated immunity to EBV.  相似文献   
2.
Summary We have previously described a phage (63) for generalized transduction in Bacillus thuringiensis and used it for mapping of four chromosomal antibiotic resistance markers, namely nalA-rifA-strA-spcA (Landén et al. 1981). From 63 we have now isolated a host range mutant called 64 which contains 52–56 megadalton of DNA. Phage 64 was found to be a more efficient transducing vector than 63. The host range of 64 is wide, with good growth on subspecies gelechiae, kurstaki, galleriae, thuringiensis and thompsoni, restriction on some derivatives of finitimus and ostrinae and no growth on alesti, israelensis and aizawai.Using 64 and a series of new mutants of subspecies gelechiae we have no added five new genes to the antibiotic resistance group described before. The gene order found was guaB-purB-metA-novA-(purA-nalA)-rifA-strA-spcA. Linkage was also demonstrated between hisA and lysA.  相似文献   
3.
Some methodological aspects of the intracerebral microdialysis technique have been investigated: the existence of a pressure gradient at the level of the dialyzing membrane, the substance diffusion from the microdialysis probe and the extent of tissue damage induced by the implantation of the microdialysis probe. At the level of the dialyzing membrane a rough balance between the pressure inside the probe and the one present in the extracellular fluid compartment has been observed. The pattern of substance diffusion in the tissue showed a large variability depending on the substance used and the experimental conditions. Relevant deductions can be made by the use of labeled markers. By means of this approach, the diffusion pattern of tritiated ganglioside GM1 in the tissue around the probe could be shown to follow a biexponential pattern, suggesting a two-step process of diffusion. The degree of tissue damage induced by the microdialysis probe was assessed by analyzing the glial reaction, and was measured by means of semiquantitative immunocytochemistry of glial fibrillary acidic protein immunoreactivity. Only a limited area of neuronal damage was observed in the region surrounding the microdialysis probe. The amount of glial reaction after probe implantation was shown to be comparable with that induced by the implantation of a microinjection cannula.  相似文献   
4.
Denys-Drash syndrome (DDS) is characterized by early onset nephropathy, pseudohermaphroditism in males and a high risk for developing Wilms' tumour (WT). The exact cause of DDS is unknown but germline mutations in the Wilms' tumour suppressor gene (WT1) have recently been described in the majority of DDS patients studied. These mutations occur de novo and are clustered around the zinc finger (ZF) coding exons of the WT1 gene. Analysis of exons 2–10 of the WT1 gene in constitutional DNA from five patients with DDS was carried out using the polymerase chain reaction (PCR) and direct DNA sequencing. In four out of the five patients, heterozygous germline mutations were found: a novel point mutation in exon 8 (ZF2) at codon 377 altering the wild-type histidine to arginine, and three previously described point mutations in exon 9 (ZF3) in the codons corresponding to amino acids 394Arg and 396Asp. In one patient, no mutations could be demonstrated. In three patients where parental DNA was available, the mutations were shown to have occurred de novo. Furthermore, since tumour DNA in two of these cases had lost the wild-type allele, polymorphic markers from the short arm of chromosome 11 were used to determine the parental origin of the mutant chromosome. In both cases, the mutant chromosome was shown to be of paternal origin. Since the majority of published WT1 mutations in DDS patients alter a RsrII restriction site in exon 9, we were able to perform PCR-based diagnosis in a female patient with early renal insufficiency and normal external genitalia.  相似文献   
5.
A study was performed to investigate possible interactions by magnetic fields (MF) with the processes of initiation and promotion of chemically induced preneoplastic lesions in rat liver. Male Sprague-Dawley rats were subjected to a 70% partial hepatectomy followed after 24 h by i.p. injection of diethylnitrosamine (DENA) as a tumour initiator. Starting one week after the DENA-treatment phenobarbital (PB) was given to promote growth of enzymatically altered foci of liver cells. MF was applied immediately after the partial hepatectomy and continued until sacrifice after 12 weeks of PB exposure. Homogenous horizontal AC magnetic fields with a frequency of 50 Hz and flux densities of 0.5 μT or 0.5 mT were used. The rats coexposed with MF and DENA plus PB did not gain weight as much as the rats exposed to the chemical agents only. The MF-exposure also resulted in a slight reduction in size and numbers of the focal lesions. The results suggest an interaction of MF with the processes of chemical carcinogenesis either as a result of stress or depending on effects on the proliferation of preneoplastic cells. © 1993 Wiley-Liss, Inc.  相似文献   
6.
The Beckwith-Wiedemann syndrome (BWS) is characterized by somatic overgrowth, developmental anomalies, and proneness to embryonic tumor development. The majority of cases are sporadic, but several families with an autosomal dominant mode of inheritance with variable expression and reduced penetrance have been described. In three such families, BWS has been linked to DNA markers for the insulin gene (INS) and H-ras on chromosome band 11p15. Two additional families with inherited BWS are described here. Linkage analysis has been performed with a highly informative marker for the tyrosine hydroxylase (TH) locus within the INS-IGF2 (insulin-like growth factor II)-TH gene cluser and confirms the previous observed linkage to this region (lod score 2.16 at = 0). Linkage analysis to TH provides a basis for informed genetic counselling and carrier detection in the hereditary form of the syndrome. Based on the hypothesis that IGF2 may be a candidate gene for BWS, we screened for mutations in the coding exons 7 and 9, but found no abnormalities in 5 unrelated BWS cases.  相似文献   
7.
8.
Kinetic parameters for high affinity [HA] uptake in vitro in synaptosomes from different mouse brain regions were investigated. Vmax was highest in the striatum [200 pmol.· mg protein?1 · 4 min?1], followed by the cortex [111 pmol · mg protein?1 · 4 min?1], hippocampus [63 pmol · mg protein?1 · 4 min?1], midbrain [21 pmol · mg protein?1 · 4 min?1] and, lowest, medulla oblongata [5 pmol · mg protein?1 · 4 min?1]. Km was about the same in all brain regions [0.9–1.4 μM]. No sign of HA uptake was detected in synaptosomes from the cerebellum. A clear relationship between Vmax for synaptosomal HA uptake of Ch in vitro and apparent turnover of ACh in vivo was found between the brain regions. Administration of oxotremorine [1 mg·kg?1 i.p.] decreased Vmax for HA uptake of Ch by 60% in the cortex and hippocampus, by 50% in the striatum and by 20% in the midbrain. This effect is in accordance with the previously observed marked decrease in turnover of ACh in these brain regions following oxotremorine treatment.  相似文献   
9.
Gel chromatography of kidney postmitochondrial fractions from control rats 2 hr after injection of 203Pb or after in vitro incubation with 203Pb disclosed the presence of two fractionated Pb-binding components plus binding in the void volume and total volume regions. The binding of Pb to the two components, with molecular weights of 11,500 and 63,000 daltons, was markedly decreased in Pb-pretreated rats. Sodium dodecyl sulfate-gel electrophoresis and autoradiography showed the presence of one major 203Pb band with an estimated molecular weight of 60,000 daltons. The 11,500-dalton peak did not incorporate 14C-leucine nor did concomitant administration of cycloheximide with the 203Pb inhibit incorporation of 203Pb activity, suggesting that the component is a preformed constituent of the kidney. In vitro incubation of brain, liver and lung postmitochondrial supernatants with 203Pb disclosed that these two binding components were also present in brain but not in liver or lung, suggesting a target tissue-specific localization for these Pb-binding macromolecules.  相似文献   
10.
The Shibata shift is a change in the absorption maximum of chlorophyllide from 684 to 672 nanometers that occurs within approximately 0.5 hour of phototransformation of protochlorophyllide to chlorophyllide. Two compounds, clomazone and amiprophos-methyl, which previously have been shown to inhibit the Shibata shift in vivo, were used to look for correlations between the Shibata shift and other processes that occur during etioplast to chloroplast transformation. Leaf sections from 6-day-old etiolated wheat seedlings (Triticum aestivum L. cv Walde) were treated with 0.5 millimolar clomazone or 0.1 millimolar amiprophos-methyl in darkness. In addition to the Shibata shift, the esterification of chlorophyllide to chlorophyll and the relocation of protochlorophyllide reductase from the prolamellar bodies to the developing thylakoids were inhibited by these treatments. Prolamellar body transformation did not appear to be affected by amiprophos-methyl and was only slightly affected by clomazone. The results indicate that: (a) there is a strong correlation between the occurrence of the Shibata shift and esterification activity; (b) transformation of the prolamellar bodies does not depend on the Shibata shift; and (c) the occurrence of the Shibata shift may be a prerequisite to the relocation of protochlorophyllide reductase from prolamellar bodies to thylakoids.  相似文献   
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