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Biomedical subjects

I Oishi

Publications and source records attributed to I Oishi.

At least 55 records · Page 3Linked to original sources
PubMed1994

Functional activation of Jak1 and Jak3 by selective association with IL-2 receptor subunits.

The interleukin-2 receptor (IL-2R) consists of three subunits: the IL-2R alpha, IL-2R beta, and IL-2R gamma chains, the last of which is also used in the receptors for IL-4, IL-7, and IL-9. Stimulation with IL-2 induces the tyrosine phosphorylation and activation of the Janus kinases Jak1 and Jak3. Jak1 and Jak3 were found to be selectively associated with the "serine-rich" region of IL-2R beta and the carboxyl-terminal region of IL-2R gamma, respectively. Both regions were necessary for IL-2 signaling. Furthermore, Jak3-negative fibroblasts expressing reconstituted IL-2R became responsive to IL-2 after the additional expression of Jak3 complementary DNA. Thus, activation of Jak1 and Jak3 may be a key event in IL-2 signaling.

Animals↗
PubMed1994

Signal transduction mediated by the reconstituted IL-2 receptor. Evidence for a cell type-specific function of IL-2 receptor beta-chain.

The binding of IL-2 to its specific receptor (IL-2R) triggers various cellular events including the induction of nuclear proto-oncogenes (c-fos, c-jun and c-myc genes) and the proliferation of hemopoietic cells. In the present study, we have established NIH 3T3 fibroblasts in which the three IL-2R subunits, the alpha-chain (IL-2R alpha), the beta-chain (IL-2R beta), and the gamma-chain (IL-2R gamma), are constitutively expressed. The resulting cell lines express high affinity IL-2R on their cell surface at levels comparable with those of IL-2-responsive lymphoid cells. We observed that the high affinity IL-2R in NIH 3T3 fibroblasts can mediate the IL-2-stimulated tyrosine phosphorylation of p42/p44 (mitogen-activated protein kinase) and the induction of the c-fos, c-jun and c-myc genes. In NIH 3T3 fibroblasts the high affinity IL-2R bearing a deletion of a region rich in acidic amino acids (the "acidic" region) in the IL-2R beta-chain failed to induce the tyrosine phosphorylation of MAP kinase as well as the expression of the all three nuclear proto-oncogenes. On the other hand, our previous studies had demonstrated that the high affinity IL-2R bearing the same mutant IL-2R beta-chain retained the ability to induce c-myc gene in response to IL-2 in a murine IL-3-dependent pro-B cell line, BAF/B03. Hence, these results reveal the underlying complexity of signal transduction among different cell types. The inability of the reconstituted high affinity receptor to mediate the IL-2-induced proliferation of NIH 3T3 fibroblasts suggests that induction of the three nuclear proto-oncogenes and the tyrosine phosphorylation of mitogen-activated protein kinase in NIH 3T3 fibroblasts are not sufficient to induce cellular proliferation.

3T3 Cells↗
PubMed1994

A large outbreak of acute gastroenteritis associated with astrovirus among students and teachers in Osaka, Japan.

In June 1991, a large outbreak of acute nonbacterial gastroenteritis occurred among students and teachers at 10 primary and 4 junior high schools in Katano City, Osaka, Japan. The outbreak affected > 4700 persons, lasted 5 days, and was believed to have been linked to contaminated food from a common supplier. Astrovirus, identified as the etiologic agent, was detected by direct electron microscopy in 10 of 38 fecal samples obtained from patients with diarrhea. Detection was confirmed by solid-phase immune electron microscopy (IEM), EIA, reverse transcription-polymerase chain reaction, and virus isolation in CaCo-2 cells. Several patients who had astrovirus in their stool also demonstrated a significant antibody response to a reference strain of astrovirus by IEM and EIA and to their own isolate by IEM. Astrovirus can be an important agent of epidemic acute nonbacterial gastroenteritis in school-aged children and adults in Japan.

Acute Disease↗
PubMed1994

Astrovirus as a cause of gastroenteritis in Japan.

We used an enzyme immunoassay (EIA) to screen for astrovirus in stool specimens from outbreaks and sporadic cases of gastroenteritis collected between 1982 and 1992 in six prefectural public health institutes in Japan. Three outbreaks of gastroenteritis involving schoolchildren and adults were confirmed to be attributable to astrovirus. Astrovirus was detected in 6 to 10% of the specimens from patients with sporadic gastroenteritis from whom no other bacterial or viral agent had been identified. Among the sporadic cases, astrovirus was most frequently detected in infants less than 1 year of age, and the incidence peaked in March and April. Using specimens from recent outbreaks, we found that the EIA was more sensitive than electron microscopy (EM) for the detection of astrovirus, and many EM-negative specimens were positive by EIA. However, some stool specimens previously found to have astrovirus-like particles by EM were negative by EIA, perhaps because of inadequate storage conditions, such as long-term storage and repeated freezings and thawings. Our results indicate that astrovirus is more commonly associated with childhood gastroenteritis than has been previously appreciated and suggest that further studies to examine the epidemiology and disease burden of this virus are needed.

Adolescent↗
PubMed1994

Sequence diversity of small, round-structured viruses in the Norwalk virus group.

We have determined the nucleotide sequences of a highly conserved region of the RNA-dependent RNA polymerase of the prototype Snow Mountain agent (SMA) and of four other small, round-structured viruses (antigenically Norwalk virus [NV]-like or SMA-like) following reverse transcription-PCR amplification of viral RNA obtained from human stools. The stool samples were either from volunteers administered SMA or from sporadic cases and outbreaks of gastroenteritis that occurred in Japan and the United Kingdom between 1984 and 1992. The GLPSG and YGDD RNA polymerase motifs were in the proper locations in the sequences of the five SRSVs, but each sequence was distinct from the 8FIIa prototype NV sequence and from each other. Analysis of the sequences and reactivities in a new NV antigen enzyme-linked immunosorbent assay showed that the five viruses could be divided into two groups (serogroups) with NV and SMA, respectively, being the prototypes. The sequences of the capsid region and a nonstructural region (2C) were determined from one strain from each group. One virus (SRSV-KY-89/89/J), isolated in Japan and antigenically similar to the prototype NV (isolated 21 years earlier in Ohio), showed a remarkable level of sequence similarity to NV. KY-89 and the 8FIIa NV showed 87.2% nucleotide similarity over 2,516 continuous nucleotides amounting to 96 to 98.9% amino acid similarity in three distinct domains in two open reading frames. Between the prototype SMA and NV, the polymerase region showed 63% nucleotide and 59% amino acid similarity, respectively. Two other antigenically SMA-like isolates (SRSV-925/92/UK and SRSV-OTH-25/89/J), from the United Kingdom and Japan, showed 80% nucleotide and 88 to 92% amino acid similarity in the polymerase region to the prototype SMA isolated 16 and 13 years earlier in the United States. The capsid region of the antigenically SMA-like OTH-25 virus showed 53% nucleotide and 65% amino acid similarity to the prototype NV capsid region. Domains of sequence diversity and conversation were identified within the capsid protein of these two distinct prototype serotypes of virus. These results indicate that NV-like and SMA-like agents are still circulating, and sequence comparisons will be useful to identify and classify distinct viruses in the NV group.

Base Sequence↗
PubMed1993

An occurrence of diarrheal cases associated with group C rotavirus in adults.

Six of the 23 college students who joined a group trip in February of 1991 developed acute nonbacterial gastroenteritis with severe diarrhea. The causal agent was identified as group C rotaviruses by electron microscopy (EM), immune-EM (IEM) and the molecular examinations including polyacrylamide gel electrophoresis (PAGE) and polymerase chain reaction (PCR) on virus particles detected in the extract of watery fecal specimens of the patients. The patients positive for virus isolation showed significant increase in IEM antibody to the isolated virus in their paired sera. These findings suggest that the group C rotavirus is an important etiological agent of diarrhea and may also cause serious food-borne diarrheal disease in adults.

Adult↗
PubMed1992

Demonstration of low molecular weight polypeptides associated with small, round-structured viruses by western immunoblot analysis.

Small, round-structured viruses (SRSV) were detected in 14 of 300 fecal specimens obtained from patients with acute gastroenteritis by electron microscopy. These SRSV strains were morphologically indistinguishable from one another. While 11 of these strains had a single usual major structural protein with molecular weight of 63,000 (63K) daltons (p63), interestingly, three strains possessed a single major structural protein with molecular weight of 33K daltons (p33). Treatments of p63-SRSV with proteolytic enzymes or denaturating reagents did not affect the molecular weight of p63, and the p33 was not detectable by Western immunoblot in the ultracentrifugal supernatant of the p63-SRSV suspension. These results suggest that the p33 is neither a definitive subunit of p63 nor disintegrated component derived from the p63-SRSV but a novel polypeptide of SRSV. Immune electron microscopy and Western immunoblot analyses indicated that p63- and p33-SRSVs may share an antigenic determinant(s).

Acute Disease↗
PubMed1991

Serial observations of chronic rotavirus infection in an immunodeficient child.

Chronic rotavirus infection of an infant with severe combined immunodeficiency (SCID) was studied by virological examinations in association with long-term observation of his symptoms and immune status. During eleven months of hospitalization, the patient was suffering from incurable severe diarrhea with persisting excretion of rotaviruses detected by electron microscopy and the reversed-passive hemagglutination (R-PHA) test and had transient hepatitis symptom despite multiple administrations of human gammaglobulin and high calorie fluids. The detected viruses were morphologically recognized as rotavirus with double capsid structure. Polyacrylamide gel electrophoretic (PAGE) analysis of their genomic RNAs showed the long electropherotype of group A virus with abnormal migration profiles changing considerably from the early to the late phase of illness: (1) The 11th segment became undetectable; (2) the molecular weight of the 6th segment slightly increased; (3) seven to fourteen extra segments appeared; and (4) PAGE patterns of viral genomic RNAs changed every three or four months. These findings suggest that chronic infection with rotavirus accompanied the generation of extra viral genomic segments and their unusual assortments in an immunodeficient host.

Chronic Disease↗
PubMed1990

Removal of pathogenic human viruses by insoluble pyridinium-type resin.

Cross-linked poly(N-benzyl-4-vinylpyridinium bromide) (BVP resin) was found to be very efficient in removing pathogenic human viruses from aqueous solution. In batch removal experiments using 50 g/l of BVP resin at 35 degrees C, the level of infectivity in suspensions of enterovirus, herpes simplex virus, poliovirus, and human immunodeficiency virus was reduced 1000-100,000 fold during a 2 h period. Those of coxsackievirus and echovirus were reduced 60-600 fold during 1 h contact. The haemagglutination titres of solutions of human rotavirus, influenza virus, human adenovirus, and Japanese encephalitis virus were reduced 16-256 fold during 30 min of contact. In removal experiments by a continuous flow column method for poliovirus, enterovirus, and coxsackievirus with initial infectivities of less than 10(5)/ml, the infectivity of these viruses was no longer detectable in the effluent solution. For poliovirus, coxsackievirus, and echovirus with initial infectivities higher than 10(6), 99.8-99.9998% of the input viruses was removed as indicated by the reduction of infectivity.

Adenoviruses, Human↗
PubMed1990

Antigenic and genetic analyses of human rotavirus with dual subgroup specificity.

In our previous study (S. Urasawa, T. Urasawa, K. Taniguchi, F. Wakasugi, N. Kobayashi, S. Chiba, N. Sakurada, S. Morita, O. Morita, M. Tokieda, T. Kawamoto, K. Minekawa, and M. Oseto, J. Infect. Dis. 160:44-51, 1989) of antigenic characterization of about 300 human rotavirus (HRV) isolates collected at different localities in Japan, we found 4 HRV isolates having unique antigenic and genetic constructions. The four strains possessed both subgroup I and subgroup II antigens, serotype 3 antigen, and a long RNA electropherotype. The reactivity pattern of these four HRV isolates with three monoclonal antibodies (MAbs) directed to an outer capsid protein, VP4, and with one MAb directed to an inner capsid protein, VP2, was clearly different from those of usual subgroup II HRVs having serotype 1, serotype 3, or serotype 4 specificity and a long RNA pattern, whereas their reactivity pattern was similar to that of strain K8 (subgroup II, serotype 1), which possessed unique VP4 and VP2 proteins. RNA-RNA cross-hybridization analysis indicated that while the four isolates were genetically distinct from the two genetic groups of HRV reported previously, i.e., the Wa family (strains KU, S3, and YO) and the DS-1 family (strain S2), they were closely related to strain K8, a strain having unique antigenic and genetic properties (K. Taniguchi, K. Nishikawa, T. Urasawa, S. Urasawa, K. Midthun, A. Z. Kapikian, and M. Gorziglia, J. Virol. 63:4101-4106, 1989).

Antigens, Viral↗
PubMed1985

Three-year survey of the epidemiology of rotavirus, enteric adenovirus, and some small spherical viruses including "Osaka-agent" associated with infantile diarrhea.

Studies were made by electron microscopy (EM) on the viruses associated with diarrhea of outpatients at a pediatric clinic in Osaka Prefecture during the three year period from 1980 through 1982. The viruses detected by EM by negative staining with phosphotungstic acid (PTA) were classified morphologically into 6 groups: rotavirus, adenovirus and four kinds of small spherical viruses, calicivirus, astrovirus, picornavirus/parvovirus (P/P)-like agent and Osaka-agent. Osaka-agent seems to be a newly identified small virus. It is 35-40 nm in diameter with a fringe of spike-like structures on its surface. Viruses were detected in 181 of the 395 cases of diarrhea (45.8%). Rotavirus was detected in 122 (30.9%) of the total cases and in 67.4% of the virus-positive cases, while other viruses were detected in 15% of the total cases; adenovirus in 23 (6%) and small agents in 36 (9%). Rotavirus infection showed a distinctive seasonal variation, being mainly restricted to cooler months, but infections with other viruses did not show any seasonal variation. The age distribution of patients suggested that infants of 0 to 2 years old are very susceptible to all viruses. Attempts to cultivate these viruses in vitro were successful with only two isolates of adenovirus type 5.

Acute Disease↗
PubMed1980

Percutaneous transhepatic drainage: experience in 100 cases.

A two-step procedure for percutaneous transhepatic drainage (PTD) of the biliary tract was attempted on 101 patients with obstructive jaundice, 29 with benign and 71 with malignant lesions, and was successful in 100. With this procedure, marked clinical improvement, with reduction in levels of serum bilirubin, SGOT, SGPT and alkaline phosphatase, was achieved after 1-2 weeks as a preoperative step or for continuous drainage in inoperable cases. In one patient 8 dys after PTD, however, a complicating large intrahepatic hematoma proved fatal. Emergency operation was necessary in three of the four patients who developed bile peritonitis due to dislocation of the catheter and in one with intra-abdominal bleeding. Our results suggest that this procedure is very useful in the diagnosis and management of certain obstructive diseases of the biliary tract.

Adult↗
PubMed1980

Calicivirus detected in outbreaks of acute gastroenteritis in school children.

Outbreaks of acute gastroenteritis occurred in AK and N Primary Schools of Osaka Prefecture early in March and early in November, respectively, 1977. Epidemiological surveys were carried out in both schools with the following results. The morbidity rates were 21.8% (AK) and 8.5% (N) among all pupils, and 41.7% (AK) and 36.8% (N) in special age groups. The main clinical symptoms were abdominal pain (77.2-91.3%), diarrhea (38.4-41.3%) and vomiting (6.5-41.6%). Electron microscopic observations of negatively stained specimens showed that five of 15 fecal extracts obtained from patients in the two schools contained virus particles of 35-40 nm diameter with some black hollows on the surface of complete particles and ten projection-like structures at the edge of empty shells. These morphological characteristics resemble those of calicivirus particles. Immune electron microscopic examination suggested that outbreak in AK School was associated with this virus. Attempts to cultivate the viruses in various cultured cells and in suckling mice were unsuccessful.

Antibodies, Viral↗
PubMed1979

Epidemiological and virological studies on outbreaks of acute gastroenteritis associated with rotavirus in primary schools in Osaka.

There have been three recent outbreaks of acute gastroenteritis in primary schools in Osaka prefecture caused by rotavirus: one in a school (TA) in April, 1974 and two in two other schools (TE and K) in May 1975. The morbidity from the disease was 2.4--15.8% for all age groups in the schools, and 20.1--34.1% for a certain age group. The disease lasted for 4 (K) to 14 days (TE). The first cases in schools TA and TE were followed by successive cases. The main clinical symptoms were higher frequencies of diarrhea (68--71.4%) and fever (78%) than in winter vomiting disease. There was no difference in the incidences of the disease in boys and girls. From observation on the disease in individual families, the incubation period seemed to be 3 days. Using paired sera and Neonatal Calf Diarrhea Virus (NCDV) as antigen, positive seroconversion was demonstrated by the complement fixation test and marked seroconversion by the indirect fluorescent antibody technique. With these techniques, specific antibody to NCDV was detectable in the sera from an early stage of illness. Rotavirus was found on electron microscopic examination of some fecal specimens of patients in TA, but not in those of patients in TE or K, although adenovirus was isolated from one patient. A serological survey of healthy children aged 0 to 12 showed that rotavirus is a common virus in Osaka.

Acute Disease↗
PubMed1975

Responses of Clostridium botulinum type B and E progenitor toxins to some clostridial sulfhydryl-dependent proteases.

Sulfhydryl-dependent proteases produced by Clostridium botulinum types A, B, and F, Clostridium histolyticum, Clostridium sporogenes and Clostridium perfringens activate preferentially type E over type B progenitor toxin but less efficiently than trypsin. The results explain why activable toxin is demonstrable in culture of a strongly proteolytic type B strain.

Botulinum Toxins↗