Secobarbital in humans discriminating triazolam under two-response and novel-response procedures

The percentage of long-term survivors after intensive chemotherapy and the outcome of MDS patients who achieve partial remission (PR) with intensive chemotherapy (IC) are not known. Between 1981 and 1996 we treated 99 patients with de novo MDS who had high-risk MDS or progression to AML, with IC. 41 (41%) achieved CR, 16 (16%) achieved partial remission (PR), 26 (26%) had failure, and 16 (16%) died in aplasia. Eight of the patients who achieved CR were autografted, three were allografted and the remaining cases received moderate consolidation chemotherapy. After IC, the 16 PR patients fulfilled the criteria for RA in 15 cases and CMML in one case. Median PR duration was 17 months, and three PR were > 3 years (39, 50+, 82+ months). Median actuarial survival of patients who achieved PR and CR was 18 months and 20 months from the onset of IC, respectively (difference not significant). Of the 71 patients treated before 1993, with sufficient follow-up, 10 (14%) had survived > 4 years (long-term survivors). Four of them were alive in first CR after 49+ to 110+ months and probably cured, two were alive in PR after 50+ and 82+ months and four had died after 49-78 months. Long-term survivors were characterized by a significantly higher incidence of RAEB-T at diagnosis, and with normal or favourable cytogenetic findings. In patients with RAEB-T at diagnosis included before 1993, 8/23 (35%) cases who had no unfavourable karyotype had survived > 4 years. Our findings suggest that MDS patients who achieve PR with IC, and not only those who achieve CR, can benefit from this type of treatment. The percentage of long-term survivors remains low, however, and is almost restricted to patients with RAEB-T at diagnosis and no unfavourable karyotype.     

攀钢钢包自动开浇技术研究

通过信息调研、实验室研究及现场工业试验 ,研制出了适应攀钢生产条件的钢包引流剂 ,使模铸自开率从2 0 %～ 30 %提高到 95%以上 ,连铸钢包自开率从 50 %提高到 80 %以上。     

Prognosis in malignant melanoma

A uniform and practical classification and staging system for melanoma must exist and be widely adopted if useful comparisons between different treatment centers and databases are to be made. This article reviews the 1992 American Joint Committee on Cancer pTNM staging system. In this classification, localized disease without regional nodal involvement is defined as stage I or II, depending on the tumor thickness of the primary melanoma. Regional lymph node involvement and/or in-transit metastasis is defined as stage III, and systemic metastatic disease is defined as stage IV.     

Allelic deletion analyses of MMAC/PTEN and DMBT1 loci in gliomas: relationship to prognostic significance

The frequency of loss of heterozygosity (LOH) around MMAC/PTEN and DMBT1 loci and survival analyses based on the LOH status were assessed in 110 patients with different histological groups of gliomas. Twenty-six of the patients had anaplastic oligodendrogliomas, 31 had anaplastic astrocytomas, and 53 had glioblastomas multiforme (GM). At the DMBT1 locus, LOH was observed very frequently in all three histological groups, with no significant difference in the frequency of LOH among the three histological groups. At the MMAC/PTEN locus, patients with GM exhibited a significantly increased frequency of LOH (72%) compared with patients with anaplastic astrocytomas (29%) or anaplastic oligodendrogliomas (31%) (P < 0.0001). Kaplan-Meier survival plots showed that patients with LOH at the MMAC/PTEN locus had a significantly worse prognosis than did patients without LOH at the MMAC/PTEN locus [hazard ratio (LOH versus non-LOH), 2.65; 95% confidence interval (CI), 1.69-4.46; P < 0.0001]. Cox proportional hazards regression analysis, adjusted for age at surgery and histological grades (GM and non-GM), showed that LOH at the MMAC/PTEN locus was a significant predictor of shorter survival [hazard ratio (LOH versus non-LOH), 2.01; 95% CI, 1.1-3.5; P = 0.018). Our analysis failed to indicate a similar association between the frequency of LOH at the DMBT1 locus and patient survival [hazard ratio (LOH versus non-LOH), 2; 95% CI, 0.37-3.13; P = 0.2]. These results suggest that the DMBT1 gene may be involved early in the oncogenesis of gliomas, whereas alterations in the MMAC/PTEN gene may be a late event in the oncogenesis related to progression of gliomas and provide a significant prognostic marker for patient survival.     

Amelioration of virulent Babesia bovis infection in calves by administration of the nitric oxide synthase inhibitor aminoguanidine

The expression of synaptosomal-associated protein (SNAP-25), neural growth-associated protein (GAP-43) and neural cell adhesion molecule (NCAM) were studied in mouse olfactory cells and axons for 2 weeks following unilateral bulbectomy. The olfactory cells and axons in the control olfactory epithelium were positive for SNAP-25 but levels decreased in the atrophic olfactory epithelium 3 days after bulbectomy. There was no expression of SNAP-25 in the olfactory epithelium on the bulbectomy side 7 days after bulbectomy, indicating that this protein may be a good marker for the degeneration of olfactory cells. The expression of NCAM was still found in the atrophic olfactory epithelium at 7 days after bulbectomy, while the expression of NCAM in the olfactory epithelium of the bulbectomy side was stronger than that on the control side at 14 days after bulbectomy. The expression of GAP-43 in the olfactory axonal bundles of the bulbectomy side at 3 and 4 days after bulbectomy was stronger than that on the control side. These results suggest that upregulation of NCAM may be related to the regeneration of the olfactory cells, with upregulation of GAP-43 probably playing a role in axonal regeneration after bulbectomy.     

CCR5 coreceptor utilization involves a highly conserved arginine residue of HIV type 1 gp120

The seven-transmembrane CCR5 was recently found to double as a coreceptor for a genetically diverse family of human and nonhuman primate lentiviruses. Paradoxically, the main region of the envelope protein believed to be involved in CCR5 utilization was mapped to hypervariable region 3, or V3, of the envelope glycoprotein gp120. In this study, we addressed the question of whether functional convergence in CCR5 utilization is mediated by certain V3 residues that are highly conserved among HIV type 1 (HIV-1), HIV type 2, and simian immunodeficiency virus. Site-directed mutagenesis carried out on three such V3 residues revealed that the Arg-298 of HIV-1 gp120 has an important role in CCR5 utilization. In contrast, no effect was observed for the other residues we tested. The inability of Arg-298 mutants to use CCR5 was not attributed to global alteration of gp120 conformation. Neither the expression, processing, and incorporation of mutant envelope proteins into virions, nor CD4 binding were significantly affected by the mutations. This interpretation is further supported by the finding that alanine substitutions of five residues immediately adjacent to the arginine residue had no effect on CCR5 utilization. Taken together, our data strongly suggests that the highly conserved Arg-298 residue identified in the V3 of HIV-1 has a significant role in CCR5 utilization, and may represent an unusually conserved target for future anti-viral designs.     

Chromosomal instability is correlated with telomere erosion and inactivation of G2 checkpoint function in human fibroblasts expressing human papillomavirus type 16 E6 oncoprotein

Cell cycle checkpoints and tumor suppressor gene functions appear to be required for the maintenance of a stable genome in proliferating cells. In this study chromosomal destabilization was monitored in relation to telomere structure, lifespan control and G2 checkpoint function. Replicative senescence was inactivated in secondary cultures of human skin fibroblasts by expressing the human papillomavirus type 16 (HPV-16) E6 oncoprotein to inactivate p53. Chromosome aberrations were enumerated during in vitro aging of isogenic control (F5neo) and HPV-16E6-expressing (F5E6) fibroblasts. We found that structural and numerical aberrations in chromosomes were significantly increased in F5E6 cells during aging in vitro and fluorescence in situ hybridization (FISH) analysis using chromosome-specific probes demonstrated the occurrence of rearrangements involving chromosome 4 and 6 in genetically unstable F5E6 cells. Flow cytometry and karyotypic analyses revealed increased polyploidy and aneuploidy in F5E6 cells only at passages > 16, although these cells displayed defective mitotic spindle checkpoint function associated with inactivation of p53 at passages 5 and 16. G2 checkpoint function was confirmed to be gradually but progressively inactivated during in vitro aging of E6-expressing cells. Aging of F5neo fibroblasts was documented during in vitro passaging by induction of a senescence-associated marker, pH 6.0 lysosomal beta-galactosidase. F5E6 cells displayed extension of in vitro lifespan and did not induce beta-galactosidase at high passage. Erosion of telomeres during in vitro aging of telomerase-negative F5neo cells was demonstrated by Southern hybridization and by quantitative FISH analysis on an individual cell level. Telomeric signals diminished continuously as F5neo cells aged in vitro being reduced by 80% near the time of replicative senescence. Telomeric signals detected by FISH also decreased continuously during aging of telomerase-negative F5E6 cells, but telomeres appeared to be stabilized at passage 34 when telomerase was expressed. Chromosomal instability in E6-expressing cells was correlated (P < 0.05) with both loss of telomeric signals and inactivation of G2 checkpoint function. The results suggest that chromosomal stability depends upon a complex interaction among the systems of telomere length maintenance and cell cycle checkpoints.