MPTP对鼠肝脂质过氧化作用的影响

本文报道给C57小鼠腹腔注射不同剂量1-甲基-4-苯基-1,2,3,6-四氢吡啶(MPTP)后,发现组3(MPTP35 mg/kg,每天一次,共7天)鼠肝匀浆、线粒体和微粒体的膜丙二醛含量明显增加,与对照组相比分别增加70.5%,67%和51.4%(P<0.01),而组1(MPTP 35mg/kg,每4小时一次,共3次)和组2(MPTP35mg/kg,每天一次,共4天)鼠肝丙二醛含量与对照组相近。结果表明MPTP有明显地促进鼠肝脂质过氧化的作用,并与其剂量有关。     

Interleukin 1 receptor antagonist (IL1RA) in acute leukaemia: IL1RA is both secreted spontaneously by myelogenous leukaemia blasts and is a part of the acute phase reaction in patients with chemotherapy- induced leucopenia

Abstract: Blast cells derived from peripheral blood of patients with acute myelogenous leukaemia (AML) were cultured in vitro and interleukin 1 receptor antagonist (IL1RA) concentrations determined in culture supernatants. AML blasts derived from patients classified as AML-M4 and AML-M5 subtype showed an increased release of IL1RA. IL1α and IL1β caused a similar increase in AML blast release of IL1RA, and addition of anti-ILl antibodies decreased IL1RA release. IL1RA release from AML blasts was also increased by stem cell factor, tumour necrosis factor α (TNFα), granulocyte-macrophage colony-stimulating factor and macrophage colony-stimulating factor, whereas interleukin 3, interleukin 6, leukaemia inhibitory factor and granulocyte colony- stimulating factor did not significantly alter IL1RA release. When investigating IL1RA serum levels, serum concentrations were decreased in acute leukaemia patients with chemotherapy-induced cytopenia compared with healthy controls. Serum levels of both IL1RA as well as IL1β and soluble TNFα receptors increased when the leucopenic patients developed complicating bacterial infections.     

115 BRCA1基因与乳腺癌研究进展

乳腺癌易感基因BRCA1作为抑癌基因,其编码产物在细胞周期调控、DNA损伤修复以及肿瘤细胞的凋亡中扮演着重要角色.大量研究证明,BRCA1基因结构、功能异常与乳腺癌的发生发展有十分密切的联系.本文拟就BRCA1与乳腺癌相关研究的最新进展作一综述.     

Molecular analysis and polymorphism of the DLA-DQB genes

Abstract: Partial-length cDNA clones and full-length genomic clones corresponding to a complete canine DQB class It gene were isolated. Southern analyses suggested the presence of two DQB genes - one of which appeared to be a pseudogene lacking exon 2 called DQB2. The other DQB gene, called DQB1, was isolated from a genomic phage clone and contained six exons. The DQB1 clone was restriction mapped, and exon 2 was sequenced from 70 dogs. Twenty alleles were found. Most of the amino acid substitutions occurred at putative positions in the peptide binding site. Inheritance of these sequences showed Mendelian segregation with one or two alleles per dog. Cluster analysis of the nucleotide and predicted amino acid sequences subdivided the canine DQB1 alleles into four major allelic groups. The number of nonsynonymous changes was higher than the number of synonymous changes in the putative antigen recognition sites suggestive of positive selection.     

复方甘油注射液长期毒性试验

复方甘油注射液系新脱水药。为了确定该药反复使用有无蓄积性中毒作用及最大无作用量，作者以大鼠和狗进行为期２８天的长期毒性试验。两种动物皆设立生理盐水对照组，低剂量组（大鼠为１０ｍｌ／ｋｇ，狗为１．７ｍｌ／ｋｇ），高剂量组（大鼠为４５ｍｌ／ｋｇ，狗为１３ｍｌ／ｋｇ）。按规定剂量每天一次静注给药，连续２８天。结果表明，两种动物均未出现明显的机能性变化，以及特异性靶器官、靶细胞的损害。故认为大鼠和狗对受试物的最大无作用量分别大于４５ｍｌ／ｋｇ和１３ｍｌ／ｋｇ。     

Cloning and characterisation of the adenosyl phosphosulphate kinase gene from Aspergillus nidulans

The sD gene of Aspergillus nidulans has been cloned by heterologous screening of rationally selected cosmids. Co-transformation of the sD50 mutant JMP1 confirmed the presence of a functional gene. Sequence analysis determined this gene to be 680 bp in length, containing a 59-bp intron and encoding a protein of 206 amino acids. A protein-sequence comparison revealed a similarity to the C-terminal region of ATP sulphurylase, the sC gene product. Further sequence comparison revealed differences in a consensus sequence ATP-binding motif, indicating non-functionality of the APS kinase-like domain of ATP sulphurylase, and confirms sD as the gene encoding APS kinase in A. nidulans. Received: 17 April / 29 August 1997     

Prognostic Factors in Myeloma: What They Tell Us About the Pathophysiology of the Disease

Prognostic factors in myeloma are not only important for allowing comparisons to be made between therapeutic protocols but they also provide us with an insight into the pathophysiology of the disease and important mechanisms which result in disease progression. Prognostic factors in myeloma relate to the inherent proliferative capacity of the malignant clone, tumor bulk, renal function and other factors which reflect tumor host and host tumor interactions. The highly significant effect of the labelling index (LI) suggests that the clonogenic cell is ontologically very close to the malignant plasma cell on which the labelling index is derived. The explanation for the important role of the β2-microglobulin (β2M) level over and above its reflection of renal function is as yet unclear.     

Expression of Human Recombination Activating Genes (RAG-1 and RAG-2) in Lymphoma

Two recently discovered genes, the recombination activating genes 1 and 2 (RAG-1 and RAG-2), are necessary to perform variable (V), diversity (D), and joining (J) recombination. They synergistically activate VDJ recombination to generate immunocompetent lymphocytes. Disruption of either gene results in a maturation arrest at a very early B and T cell progenitor stage. Expression and downregulation of RAG's are closely associated with interleukin 7, sIgM and TCR-CD3 complex, respectively. Assessment of RAG mRNA expression is a valuable marker in identifying the genotypic maturation status of leukemias and lymphomas. Persistent RAG expression in otherwise mature lymphoid proliferations may explain puzzling biological and clinical observations such as multiple rearrangements in lymphomas with a mature phenotype. Lack of RAG expression in Hodgkin's disease with abundant Reed-Stern-berg cells is consistent with a mature phenotype of the latter. Availability of a anti-RAG-1 monoclonal antibody in the near future will facilitate RAG analysis of lymphomas.     

Effect of low glycogen on glycogen synthase in human muscle during and after exercise

Subjects cycled at a work load calculated to elicit 75% of maximal oxygen uptake on two occasions: the first to fatigue (34.5 ± 5.3 min; mean ± SE), and the second at the same workload and for the same duration as the first. Biopsies were obtained from the quadriceps femoris muscle before and immediately after exercise, and 5 min post-exercise. Before the first experiment, muscle glycogen was lowered by a combination of exercise and diet, and before the second, experiment muscle glycogen was elevated. In the low glycogen condition (LG), muscle glycogen decreased from 169 ± 15 mmol glucosyl units kg^-1dry wt at to rest to 13 ± 6 after exercise. In the high glycogen condition (HG) glycogen decreased from 706 ± 52 at rest to 405 ± 68 after exercise. Glycogen synthase fractional activity (GSF) was always higher during the LG treatment. During exercise in the HG condition, those subjects who cycled for < 35 min (n= 3) had GSF values in muscle which were lower than at rest, whereas those subjects who cycled for > 35 min (n= 4) had values which were similar to or higher than at rest. Thus the change in GSF in muscle during HG was positively related to the exercise duration (r= 0.94; y = 254–17x + 0.3x²; P < 0.001) and negatively related to the glycogen content at the end of exercise (r=–0.82; y= 516–2x + 0.001x²; P < 0.05). During LG exercise GSF remained constant. GSF increased markedly after 5 min post-exercise in both HG and LG conditions. cAMP dependent protein kinase activity increased similarly during both LG and HG exercise and reverted to the preexercise values 5 min post-exercise. It is concluded that muscle contraction decreases GSF, but low glycogen levels can attenuate or abolish the decrease in GSF. The rapid increase of GSF during recovery from exercise does not require glycogen depletion during the exercise.