Emergence of rare sapovirus genotype among infants and children with acute gastroenteritis in Japan.

A total of 1,154 fecal specimens from infants and children with acute gastroenteritis in five cities in Japan (Maizuru, Tokyo, Sapporo, Saga, and Osaka), collected from July 2003 to June 2005, were tested for the presence of diarrheal viruses by reverse transcriptase multiplex PCR. Overall, 469 of 1,154 (40.6%) were positive for diarrheal viruses, of which 49 (10.4%) were positive for sapovirus. The peak of sapovirus infection shifted from April-June in 2003-2004 to October-December in 2004-2005. The observations show that maximum sapovirus prevalence can occur during warmer seasons. Sapovirus was subjected to molecular genetic analysis by sequencing. The results indicated that sapovirus genogroup I was a dominant group (100%). Sapovirus strains detected in this study were further classified into four genotypes (GI/1, GI/4, GI/6, and GI/8). Of these, sapovirus GI/1 was the most predominant, followed by sapovirus GI/6; these accounted for 93% (13 of 14) and 7% (1 of 14), respectively, in 2003-2004. However, it was noteworthy that sapovirus GI/6 suddenly emerged to become the leading genotype, accounting for 77% (27 of 35) of isolates in 2004-2005. This is believed to be the first report of the changing distribution of sapovirus genotypes and of the emergence of the rare sapovirus GI/6.

Changing distribution of group A rotavirus G-types and genetic analysis of G9 circulating in Japan.

A total of 1,797 fecal specimens from infants and children with acute gastroenteritis in Japan from July 2000 to June 2003 were tested for group A rotavirus by ELISA, RT-PCR, RNA-PAGE and latex agglutination methods. Of these, 439 were found to be positive for group A rotavirus and this presented 24.4%. In 2000-2001, G1 was the most prevalent (45.5%) followed by G2 (32.5%), G3 (12.3%), G9 (5.9%) and G4 (2.6%). However, G2 was found predominant with 40% in the following year (2001-2002). Interestingly, G9 had a rapid increase of infection up to 17.8%. In 2002-2003, G3 dominated over other G-types with 34%. Another interesting feature of the study was the demonstration of great genetic diversity among G9 strains in Japan. Worth of note was the first prevalence pattern of rotavirus G-types with an increase of G2, G3 as well as G9 and a decrease of G1 during the 20 year-survey of rotavirus infection in Japan.

Rapid detection and typing of oculopathogenic strain of subgenus D adenoviruses by fiber-based PCR and restriction enzyme analysis.

PURPOSE: To develop a new detection and typing method of oculopathogenic strains of subgenus D adenoviruses directly from conjunctival scrapings by a combination of polymerase chain reaction (PCR) and restriction enzyme analysis (REA). METHODS: A new PCR method using primer pairs of AF2/AR2, which are specific for the fiber genes, were developed to amplify 1150-bp products from nine oculopathogenic prototypes of subgenus D adenoviruses. Amplicons were cleaved with three restriction enzymes: DdeI, HinfI, and RsaI. Clinical specimens of 102 conjunctival scrapings were also evaluated by this PCR method. Restriction patterns of prototypes were used for the typing of clinical samples. Detection limit was determined by the PCR amplification of a known amount of purified adenovirus serotype 8 DNA. RESULTS: A novel PCR method based on the fiber genes allowed the amplification of nine oculopathogenic serotypes of subgenus D (Ad8, Ad9, Ad15, Ad17, Ad19, Ad22, Ad28, Ad37, and Ad39). As little as 38.4 fg of adenovirus type 8 could be detected by this method. Positive results were obtained from 48 of 102 samples (47%) by both hexon- and fiber-based PCR, whereas only 29 of 102 (28.4%) yielded positive results by culture isolation/neutralization test (NT). All positive specimens (29 samples) of culture isolation and PCR-RFLP methods showed positive results by our new fiber-based PCR method, and no positive products were detected from other subgenus of adenovirus or nonadenoviral DNA. CONCLUSIONS: A newly developed fiber-based PCR-REA method for the detection and typing of adenoviruses is faster than any former PCR methods. This all-in-1-day detection and typing method will be quite useful to the rapid diagnosis of subgenus D adenovirus infection.

Insulin receptors in virus-induced diabetes mellitus in mice.

Quantitative estimations were made of insulin receptors on liver cell membrane of DBA/2 mice infected with M variant of encephalomyocarditis virus. The virus produced an impairment of glucose metabolism on day 3 of infection, which lasted for 5 months. The fasting plasma insulin concentration was markedly decreased on day 14. The specific binding of 125-I insulin to the membrane receptor was significantly decreased on day 3 of infection. The binding inhibitions were stronger in male mice than in females. The number of insulin receptors began to decrease on day 1, was decreased remarkably by day 3, and returned on day 7 to the level before infection. A decrease of receptor affinity was also observed in infected animals. These results seem to show that changes in insulin receptors are one cause of the impairment of glucose metabolism in the initial phase of virus-induced diabetes.

[Glucose tolerance abnormalities in mice actively immunized with components of bovine pancreatic hormones (author's transl)]. / Abnormität Der Glucose-Toleranz Bei Den Mit Verschiedenen Komponenten Des Rinderpankreashormons Aktiv Immunisierten Mäusen.

The relationship between immune insulitis and glucose tolerance was investigated in three groups of mice following active immunization with different components of bovine pancreatic hormone. An abnormal blood glucose level was observed in the three groups ranging from 33.3% to 87.5% of sensitized mice. A relationship was not present between the glucose tolerance response and the presence of insulitis or anti-insulin antibody in the blood of sensitized mice. However, all sensitized mice with a marked decrease in glucose tolerance were found to have insulitis. In animals without established insulitis and with no demonstrable anti-insulin antibody, abnormal glucose tolerance was noted. This latter condition occurred more frequently with recrystallized insulin than with a-component and did not occur with monocomponent insulin. These findings seemed to indicate that two distinct processes involving some circulating antibodies with anti-insulin antibody and insulitis might be involved in the development of the observed glucose tolerance abnormality.