Japanese journal of medical science & biology最新文献

A human Hanganutziu-Deicher (HD) antibody and a chicken anti-N-glycolyneuroaminyllactosylceramide (HD3) antibody were compared in their reaction against HD antigen-active ganglioside (HD3) and a glycoprotein (GP) by radioimmunoassay (RIA). The human antibody had a 50 times higher reactivity with the glycoprotein, while the chicken antibody reacted equally with both antigens. Both antibodies had a higher reactivities with HD antigen(s) in sera of five of eight lung cancer patients than 54 normal human sera. Since four of the above five sera had no abnormal titers to GP, it was concluded that their immunological status was antigen excess. The chicken antibody may be useful in follow-up studies of cancer patients to correlate the expression of HD antigen in tissues and sera with the elevation of HD antibodies, offering alternative methods of clinical prognosis of tumor growth and/or metastases. The human HD antibody may also be useful for the detection of HD antigens of glycoprotein nature.

Production of a factor with a biological activity to inhibit the in vitro tumor-cell migration (TCM) from peripheral blood E rosette-forming cells (ERFC), CD4+ and CD8+ T cells in patients with gastric and breast carcinoma was investigated. The cells were stimulated for 2 or 24 hr with allogeneic gastric or breast cancer extracts in samples of cell suspensions. A microculture system at an initial cell concentration from 2,500 cells to 1 cell per well was used. Feeder cells, PHA, IL-2-containing supernatant and cancer extract were added to each well. Ehrlich ascites tumor cells were employed in the migration-inhibition assay. ERFC and CD4+ T cells produced in the culture supernatants a factor inhibiting TCM, when these cells were stimulated with cancer extracts, but not with extracts of benign tissue. Stimulated CD8+ T cells did not produce such a factor. The production of the factor inhibiting TCM in the microculture system was also significantly correlated with the type of cells in the wells, particularly with ERFC and CD4+ T cells, but not with CD8+ T cells (r = 0.94, p < 0.001). It could be suggested that this factor probably took part in in vivo blockading the migration of tumor cells in small cancer foci.

To elucidate the function of the latency-associated transcript (LAT) of herpes simplex virus type 1 (HSV-1) in productive infection and latency, we established a cell line stably expressing LAT (V24 cells). V24 cells expressed 2.0-kilobase RNA that corresponds to the major species of LAT in mouse and human sensory ganglia. When the cells were infected with HSV-1 at a low multiplicity of infection, the amount of the progeny virus was much smaller in V24 cells than in a control cell line not expressing LAT. Inefficient growth of HSV-1 in V24 cells was also observed when viral replication was initiated by transfection with viral DNA.

Antiplasmodium properties of cisplatin [cis-platinum (II) diamine dichloride], a neoplastic drug, have been assessed in in vivo and in vitro model systems of malarial parasite. A well-tolerated dose of 6 mg/kg body weight of the compound cured the mice infected with Plasmodium berghei and the amount of cisplatin required for in vitro inhibition (IC50) of a chloroquine-resistant Plasmodium falciparum isolate was smaller than either chloroquine or quinine. The minimum inhibitory concentration (MIC) needed to prevent the in vitro multiplication of asexual blood parasites was 30 ng/ml. Late ring and trophozoite stages of the erythrocytic cycle were the most susceptible, whereas schizont and early ring stages were the least sensitive to the toxic effect of cisplatin. Multiple smaller doses were more effective in curing malaria in mice than a single large dose. In a few of the mice treated with a single intraperitoneal large dose of 6 mg/kg body weight, there was a delay in appearance of parasitemia but most of them recovered completely but slowly. This compound exerts its toxicity mainly by randomly damaging and cross-linking DNA strands as shown by Southern hybridization with a synthetic oligonucleotide probe, which is a repeat sequence in the falciparum genome. The report clearly demonstrates the antimalarial potentials of this compound and suggests a closer evaluation of this and other related compounds, specially in combination with antimalarial drugs to probe their synergistic properties.

Two rages of epidemic of aseptic meningitis (AM) due to echovirus 30 (E30) in Japan were analyzed with respect to two sources of information, AM incidence and E30 isolation, both gathered through the National Epidemiological Surveillance of Infectious Diseases. The first E30 epidemic spread throughout Japan in 1983 and ceased within the year. The second epidemic, starting in 1989, continued for the three successive years, and in the last year, 1991, the total E30 reports numbered 4,061, the largest number of a single virus type ever reported. Although the epidemic showed temporal and geographical shift and lasted for one or two years in some areas, most laboratories reported the largest number of E30 isolation in 1991. Among E30-yielding cases with clinical information during 1982-1992, the associating frequency with AM was as high as 82.5%. Other central nervous system involvements such as encephalitis, myelitis, encephalomyelitis and/or paralysis were reported in 36 E30-yielding cases and their monthly and age distributions were different from those of AM cases. The proportion of such disease among E30-yielding cases (0.60%) was close to that of other enteroviruses (0.56%). During the epidemics, E30 was isolated more frequently from cerebrospinal fluid than was E4 or E9 which prevailed coincidentally. E30 was most frequently isolated from cases of 4-7 years of age, sharing the common characteristic pattern of age distribution with other enteroviral meningitis. E30-yielding cases, however, involved a large number of older age groups than those of other enterovirus infections, and this tendency was the most pronounced in the first epidemic year, 1983. The contribution of these E30 epidemics on the yearly trend of clinically reported AM incidence and on the shift of its age distribution was also analyzed.

We have demonstrated that the truncated hepatitis C (HCV) core protein with its C-terminal hydrophobic domains deleted is translocated to the nucleus of transfected cells (22). In this study, intact and truncated core proteins of HCV were transiently expressed in a human hepatoblastoma cell line, HepG2, and their effects on the expression of the chloramphenycol acethyl transferase (CAT) gene driven by viral and cellular promoters were examined. The intact core protein of 22 kDa which is localized in the cytoplasm of the transfected cells suppressed the expression in all of the promoters tested. They were promoters of the SV40 early region, the c-fos oncogene, the retinoblastoma susceptibility gene, the beta-interferon gene and the beta-actin gene. In contrast, the truncated HCV core protein located in the nucleus did not show such a suppressive activity. The HCV core protein appears to function not only as a viral structural protein but as a regulator of gene expression and it might act as a suppressive factor for the cellular gene expression.

The fusion of lysosomes and other granules with phagocytic vesicles (endo-fusion) and cell membrane (exocytosis) was simultaneously examined in non-phagocytosing guinea-pig polymorphonuclear leukocytes (PMNs). beta-Glucuronidase as a typical lysosomal enzyme, acid phosphatase as another lysosomal enzyme, and alkaline phosphatase as a specific granule enzyme were assayed. PMNs released these three enzymes in the presence of serum but the extents of exocytosis differed considerably: release of beta-glucuronidase, alkaline phosphatase and acid phosphatase was 6.9, 4.3 and 3.3%, respectively. Acid phosphatase was released even in the absence of serum, whereas the other two enzymes were not. These three enzymes showed also different responses in endofusion: the preformed phagocytic vesicles fused with the granules containing beta-glucuronidase and acid phosphatase, but scarcely fused with those containing alkaline phosphatase, although all these enzymes were recovered in increasing amounts in the phagolysosome fraction when the cells were allowed to phagocytose continuously. These results suggest that fusion of these three types of granules with phagocytic vesicles (endo-fusion) and plasma membrane (exocytosis) is heterogeneous and regulated by different mechanisms in guinea-pig PMNs.

The presentation of an antigen endogenously processed by B lymphocytes was investigated. The expression plasmid vectors, harboring genomic rearranged V genes from two monoclonal B cells and genomic mu-constant region gene, were constructed. Two B-cell lines, the MOPC104E myeloma mu-heavy chain expressing AMB line and the control hybridoma mu-heavy chain expressing AHB line, were established by gene transfection into A20.2J B lymphoma cell line. The cloned transfectant cell lines expressed surface and cytoplasmic IgM. Radioimmunoprecipitation analysis of surface IgM revealed that both cell lines used transfected mu-heavy chain and host-derived kappa-light chain. The T-cell line, MRT-2, specific for the MOPC104E protein, proliferated on AME B cell lines but not on control AHB-cell lines. MRT-2 proliferation was inhibited by anti-I-Ed,k,p,r but not by anti-I-Ad monoclonal antibody. Although the AME-transfectant lines secrete IgM into the culture medium, double chamber-type culture-experiments revealed that MRT-2 proliferation is not mediated by the uptake of secreted IgM. The results suggest that B cells process and present their own immunoglobulin heavy-chain V-region peptides to T cells in the context of MHC class-II molecules.

We examined the phylogenetical correlation between two types of JC virus (JCV) isolates, archetypes derived from the urine of nonimmunocompromised individuals and PML-types derived from the brain of patients with progressive multifocal leukoencephalopathy (PML) in Japan. A phylogenetic tree was constructed for eight JCV isolates, five PML-types obtained in this and previous studies and three representative archetypes, from DNA sequence data on the VP1 (major capsid protein) gene. The eight isolates were divided into two major groups, named subtypes MY and CY after the representative archetypal isolates. Four of five PML-type isolates belonged to subtype MY, and the other one to subtype CY. Isolates belonging to subtype MY were further divided into two groups; one group containing archetype MY and three PML-types and the other one containing archetype YI and a PML-type. These findings, together with those in our previous study that correlated various JCV isolates in the world provide evidence for the hypothesis that JCVs associated with PML may have been generated from archetypal JCVs persisting in the patients.