Japanese journal of medical science & biology最新文献

Nucleotide and deduced amino acid sequences of the outer capsid proteins VP4 and VP7 of a murine rotavirus strain (YR-1) isolated in Japan were determined. Comparisons of the VP7 amino acid sequence of YR-1 with other murine rotavirus strains (EB, EW, EC, EL and EHP) (1) showed that YR-1 was highly homologous to EB, EW, EC, EL and EHP. Moreover, YR-1 was more closely related to strains representing G3 than to any other G type. Analysis of the VP4 amino acid sequence revealed that YR-1 was highly homologous to EB, EW, EC and EL [tentatively P17 (1)], and more closely related to EHP [tentatively P18 (1)] than to any other P type. Enzyme immunoassay with monoclonal antibodies against G types (KU-4 and BH49 for G1, S2-2G10 and BW36 for G2, YO-1E2 and BC5 for G3; and ST-2G7 and BE18 for G4) and against a P type (YO-1S3, KU-12H and YO-2C2 for P8) showed no reactivity. These results indicate that YR-1 is highly homologous to EB, EW, EC and EL.

Investigations were undertaken to study the role of lupeol, a pentacyclic triterpene from Crataeva nurvala stem bark, in calcium oxalate experimental rat urolithiasis. A 2% solution of ammonium oxalate was administered by gastric intubation for inducing hyperoxaluric condition in adult male rats of Wistar strain. The duration of treatment was for 15 days. This resulted in increased urinary excretion of oxalate associated with reduction in citrate and glycosaminoglycans. The urinary marker enzymes which indicate renal tissue damage namely--lactate dehydrogenase, inorganic pyrophosphatase, alkaline phosphatase, gamma glutamyl transferase, beta-glucuronidase and N-acetyl beta-D glucosaminidase were found to be elevated. Lupeol administration (25 mg/kg body weight/day) reduced significantly the renal excretion of oxalate. It also reduced the extent of renal tubular damage as evidenced from the decreased levels of the above enzymes in urine. Such a reduction is likely to be beneficial in minimizing the deposition of stone-forming constituents in the kidney which provides antilithic effect.

We devised a simple procedure for titration of varicella-zoster virus (VZV) DNA in throat swabs from varicella patients. DNA which was extracted from throat swabs, together with known copy numbers of a cloned VZV DNA fragment, were 10-fold serially diluted and used as template in PCR. The PCR products, after heat denaturation, again serially diluted in 1.5 M NaCl and adsorbed to microplate wells. Then, biotin-labeled DNA probes were hybridized with the immobilized DNA. The hybridization signal was produced by streptavidin-conjugated beta-galactosidase and a fluorogenic enzyme substrate. By comparing the titration curves of a clinical specimen with those of the cloned fragment, of which detection limit was about 10 copies, we estimated the copy numbers of VZV DNA in the specimen. With this technique, we evaluated the degree of potential contagiousness of the patient along the course of infection: we found that varicella patients possessed highest quantity of VZV DNA in the throat on the first day of illness.

We have combined a cDNA-driven PCR technique and a non-radioactive chemical-cleavage mismatch method, followed by a direct sequencing for detecting small mutations in the human hypoxanthine-guanine phosphoribosyl transferase (HPRT) gene. HPRT cDNA was synthesized by RT-PCR from 1,000 wild-type or HPRT(-) mutant cells. Wild-type cDNA was hybridized with mutant cDNA to form heteroduplexes. The resultant mismatched bases were modified and cleaved by base-specific chemicals, followed by analysis by denaturing polyacrylamide gel electrophoresis. Cleaved fragments were detected without using radioactive materials. Finally, direct sequencing of the PCR products was performed with a focus on a small limited region indicated by the mismatch analysis (focused sequencing). In this study, three small mutations in exon-3 of HPRT cDNA were detected and characterized completely with this system. As compared with the radioactive method, this system was shown to be very simple and efficient.

Thirty-four strains of enteroinvasive Escherichia coli (EIEC) were examined for their ability to agglutinate erythrocytes from different animal species. All strains cultured in Casamino acid-yeast extract medium in the presence of 1 mM CaCl2 at 37 C for 16-22 hr induced maximal expression of hemagglutination (HA) of broad spectrum erythrocytes. The strongest HA was observed with guinea-pig erythrocytes followed by human (O type), rat, mouse, rabbit and sheep erythrocytes. All the strains failed to agglutinate chicken erythrocytes. HA was resistant to D-mannose, D-glucose, D-galactose, L-fucose, and D-fructose. Also HA was resistant to ethylene diamine tetraacetic acid (EDTA) and Na metaperiodic acid, an oxidizing agent. However, it was heat labile and completely inhibited by proteolytic enzymes such as proteinase K and trypsin, suggesting that the possible hemagglutinin of EIEC associated with the cell surface is a proteinaceous substance.

Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis, which are known as major causative organisms of periodontitis, were semiquantitatively identified by two-step polymerase chain reaction (PCR). The sets of specific primers for A. actinomycetemcomitans and P. gingivalis were prepared on the basis of the nucleotide sequences of the lktA and the fimA genes, respectively. The set of universal primers for eubacteria was designed from the nucleotide sequence of a highly conserved region in the eubacterial 16S rRNA sequence. The number of bacteria detectable by one-step PCR assay was no fewer than 10(3) cells. Less than 10(3) bacterial cells were detectable by two-step PCR assay. Subgingival plaque samples from 37 sites of 16 patients were obtained with paperpoints and analyzed by two-step PCR assay. More than 2 x 10(6) bacterial cells were found in the subgingival plaque samples from all diseased sites. In contrast, the number of total bacteria in those from more than half of healthy sites estimated by PCR assay was less than 2 x 10(6) cells, suggesting that subgingival plaque in diseased sites consists of a relatively larger number of bacteria compared with the population in healthy sites. While A. actinomycetemcomitans was detected in both healthy and diseased sites, P. gingivalis was observed only in diseased sites. Both periodontopathic bacteria occupied a minor part (less than 0.1%) of the total subgingival plaque bacteria.

The Infectious Agents Surveillance Center, the National Institute of Health, Japan, received 17,265 reports from 1982 to 1993 on cases from whom adenovirus was isolated or detected; 85% from 57 public health institutes and the other 15% from two national hospitals and two commercial diagnostic laboratories. The followings were found. Three major diseases caused by adenovirus were upper respiratory tract infection, gastroenteritis, and conjunctivitis. Patients of upper respiratory tract infection numbered 6,837 (40% of all patients due to adenovirus), the identified serotypes being in order of frequency types 3, 2, 1, and 5. Those of gastroenteritis numbered 1,636 (9.5%). From 40% of the gastroenteritis patients, adenovirus was detected by electron microscopy or immunochemical methods without cultivation. From the remaining 60%, virus was isolated in tissue culture; the serotypes of the isolates resembled those causing upper respiratory tract infection. Patients of conjunctivitis numbered 3,437 (20%), the frequency being in order of types 3, 4, 8, 37, and 19. Conjunctivitis due to types 3 and 4 prevailed every summer; type 3 was isolated often from children with pharyngo-conjunctival fever and the other four types were mostly from adults with epidemic keratoconjunctivitis. Type 3 had a unique feature not seen in other types: it was most frequently isolated, causing upper respiratory tract infection, gastroenteritis, conjunctivitis, and pharyngo-conjunctival fever. Reports on isolation of type 7, which has been reported to cause severe pneumonia in many other countries, were as few as 28 (0.2%).

Efficiency of the light trap in collecting females of Culex tritaeniorhynchus, the principal vector mosquito of Japanese encephalitis, was evaluated by mark-release-recapture experiments. Females collected with dry ice in the field were marked and released in a pigsty. The recapture rate of marked females by the light trap was so low as around 1% or lower. Owing to this low efficiency, it is not likely that the light trap can be a useful tool in the control of Japanese encephalitis.

Cyclophosphamide, and antineoplastic drug, and vitamin E, the common antioxidant present in the diet, were administered in separate dosages and in combination to animals (rats) with fibrosarcoma, metastatic tumor of the connective tissues, induced. The anticancer drug (20 mg/kg body weight) and the vitamin-E (400 mg/kg body weight) was administered for a period of 28 days from the day of tumor transplantation. The individual and the combined effects of these two substances were investigated by checking the growth of the tumor. Tumor markers like lactate dehydrogenase (LDH), serum glutamate pyruvate transminase (SGPT), serum glutamate oxaloacetate transaminase (SGOT), acid phosphatase, and alkaline phosphatase were analyzed for the changes in their concentration in serum, liver, and kidney to assess the success of the therapy. The increased level of the enzymes in the fibrosarcoma-suffering rats (GPII) was reduced by cyclophosphamide treatment (GP III) and vitamin E administration (GP IV). Among the treated groups, the combination therapy (GP V) showed greater efficacy in the treatment of fibrosarcoma than did individual administration, as there was more reduction in the levels of enzymes in Group V than those in to Groups III and IV. The enzyme levels were brought to near the normal level.

To investigate the recent prevalence of human alveolar echinococcosis in Hokkaido, we took advantage of Western blotting analysis capable of classifying persons infected with Echinococcus multilocularis into two groups: the complete and incomplete types. From the geographic distribution, the residents with the complete type appeared for the first time in 1992 in the Oshima district (western Hokkaido). The age distribution indicated that persons with the complete type increased, since 1990, in the age groups younger than 30 years old.