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Biomedical subjects

M Kishi

Publications and source records attributed to M Kishi.

At least 91 records · Page 5Linked to original sources

Sequence variability of Borna disease virus open reading frame II found in human peripheral blood mononuclear cells.

A cDNA fragment of the Borna disease virus (BDV) open reading frame II (ORF-II), which encodes a 24-kDa phosphoprotein (p24 [P protein]), was amplified from total RNA of peripheral blood mononuclear cells (PBMC) from three psychiatric inpatients. The amplified cDNA fragments were cloned, sequenced, and analyzed. A total of 15 clones, 5 from each patient, were studied. Intrapatient divergencies of the BDV ORF-II nucleotide sequence were 4.2 to 7.3%, 4.8 to 7.3%, and 2.8 to 7.1% for the three patients, leading to differences of 7.7 to 14.5%, 10.3 to 17.1%, and 6.0 to 16.2%, respectively, in the deduced amino acid sequence for BDV p24. Interpatient divergencies among the 15 clones were 5.9 to 12.7% at the nucleotide level and 12.8 to 28.2% at the amino acid level. Thus, in p24, BDV in human PBMC of the patients undergoes mutation at high rates in vivo. Additionally, we found that the nucleotide sequence of the 15 human BDV ORF-II cDNA clones differed from those of the horse strains V and He/80-1 by 4.2 to 9.3%. However, comparison of the consensus amino acid sequence deduced from the 15 human clones with those of the horse strains revealed no human-specific amino acid residue, suggesting that the BDV infecting humans may be related to that infecting horses.

Amino Acid Sequence↗

[Polymyositis after interferon beta treatment of chronic hepatitis type C].

We reported a case of polymyositis manifested after beta-interferon therapy for chronic viral hepatitis type C. In November 1992, a 62-year-old female was diagnosed as having chronic viral hepatitis type C. In January 1993, she was treated with beta-interferon(total 2.52 x 10(8)IU). In March 1993, after the treatment, she noticed weakness and atrophy of her lower extremities. Neurological examination revealed proximal dominant muscle weakness and atrophy of the extremities. Increased levels of serum CK and aldolase were disclosed on admission. By needle EMG, a low voltage with short duration interference pattern was noted. February 7, by muscle biopsy of the right quadriceps, necrotic myofibers, marked variation in fiber diameter, stromal mononuclear cell infiltration, and endomysial fibrosis was detected. The immunological stain of infiltrating cells in the muscle fibers revealed CD4:CD8 ratio as 64:55, whereas in conventional polymyositis CD8 cells dominate CD4 cells. Diagnosis of polymyositis was made and oral prednisolone 60 mg a day was started. Her symptoms and signs improved gradually and she was discharged after 2 months. Many adverse effects due to immunological disturbances caused by interferon treatment have been reported, but polymyositis due to interferon has been very rare. When interferon will be prescribed, manifestation of polymyositis should be considered.

Chronic Disease↗

Correlation between intrasinusoidal neutrophilic infiltration and ceroid-lipofuscinosis in alcoholic liver fibrosis with or without fatty change: clinicopathological comparison with nutritional fatty liver.

A histopathological study was conducted on alcoholic liver fibrosis with fatty change (21 cases) and alcoholic liver fibrosis without fatty change (18 cases) in comparison with nutritional fatty liver (27 cases). The diagnoses of alcoholic liver fibrosis groups were clinically fulfilled according to the criteria established by the Alcohol and Liver Research Group (Chief: Professor Takeuchi) of the Ministry of Education of Japan. Histological diagnosis of alcoholic liver fibrosis with fatty change was based on moderate and/or greater fatty metamorphosis of the hepatic lobules, alcoholic liver fibrosis without fatty change on a lesser degree of fatty metamorphosis than alcoholic liver fibrosis with fatty change, and nutritional fatty liver on clinicopathological features. All 66 cases were negative for viral markers of hepatitis B surface antigen and anti-hepatitis C virus in serum. Intrasinusoidal neutrophil infiltrations were significant in cases of alcoholic liver fibrosis groups more often than in cases of nutritional fatty liver. The degree of intrasinusoidal neutrophil infiltration in cases of alcoholic liver fibrosis groups was higher in cases who had last consumed alcohol recently, compared with those with longer abstinence. In alcoholic liver fibrosis with fatty change and nutritional fatty liver groups, mild-to-moderate degrees of ceroid-lipofuscinosis were recognized, but both fatty change and ceroid-lipofuscinosis were decreased according to the deterioration of fibrotic changes in alcoholic liver fibrosis with fatty change cases. On the other hand, it is significant that the frequency of ceroid-lipofuscinosis in alcoholic liver fibrosis without the fatty change group was lower than those of the alcoholic liver fibrosis with fatty change and nutritional fatty liver groups. Distribution of ceroid-lipofuscinosis has a tendency to be recognized around the central zone (zone III) of alcoholic liver fibrosis with fatty change cases with mild fibrosis, as in nutritional fatty liver cases, and the ceroid-lipofuscinosis disperses with the progression of fibrosis. These results suggest that fibrosis and fatty droplet deposition lead to microvascular heterogeneity. Therefore, the degree and distribution of fatty droplets, ceroid-lipofuscinosis, and intrasinusoidal neutrophil infiltration differ, depending on the etiology of fatty liver, and are an important histopathological barometer in cases of alcoholic liver fibrosis with fatty change and alcoholic liver fibrosis without fatty change, thus indicating the degree of fibrosis and the period since last alcohol intake.

Adult↗

Functioning survival rate of fixtures and superstructures of osseointegrated implants: ten years of progress in Tokyo Dental College Hospital (second report).

Osseointegrated implant bridges (OIB) have shown excellent results in the majority of cases. Since 1983, 1,022 fixtures has been applied to 241 superstructures in Tokyo Dental College Hospital. The aim of present study was to examine their functioning survival rate during recent ten years. The functioning survival rate of the superstructure of OIB has been almost 100% in both maxilla and mandible. Although 13.0% of these fixtures had to be removed in maxillary complete cases, only 3.3% of fixtures were removed in other cases. In maxillary complete cases, the functioning survival rate of OIB fixtures gradually decreases from 91% to 74% (91%, less than 3 years; 84%, between 3 and 7 years; 74%, more than 7 years), but it remained at about 97% for all periods in other cases. Apparently, the functioning survival rate of OIB fixture is generally determined within the period of one year, so almost the same rate is maintained thereafter. It is suggested that if more fixture numbers in the superstructure were applied to maxillary complete cases, the functional survival rate might improve.

Adolescent↗

Molecular cloning of glycoprotein antigens MGP57/53 recognized by monoclonal antibodies raised against bovine milk fat globule membrane.

A cDNA encoding 57 kDa and 53 kDa antigens (MGP57/53) recognized by monoclonal antibodies raised against bovine milk fat globule membrane (MFGM) (Biochim. Biophys. Acta 1199 (1994) 87-95) was cloned from lactating bovine mammary gland by a combination of reverse transcriptase-coupled polymerase chain reaction (RT-PCR) and 3'-rapid amplification of cDNA ends (3'-RACE). The deduced amino-acid sequence showed that mature MGP57/53 consists of 409 amino-acid residues and the calculated molecular weight and isoelectric point are 45,544 and 6.42, respectively. Computer analysis reveals that it has a significant similarity to mouse mammary epithelial cell surface protein, MFG-E8 and a human breast tumor-associated glycoprotein antigen, BA46-1. An N-terminal cysteine-rich domain and a C-terminal tandemly repeated sequence were highly conserved among them, but bovine MGP57/53 lacks 36 amino-acid residues containing a cluster of 5 prolines found in mouse MFG-E8. Northern blot analysis showed that the cDNA hybridized to about 2.0 kb mRNA of lactating bovine mammary gland. These results strongly support our previous report that the two MFGM antigens originate from a single gene and are isoforms with different N-linked sugar chains.

Amino Acid Sequence↗

Demonstration of human Borna disease virus RNA in human peripheral blood mononuclear cells.

BDV naturally infects horses and sheep, and causes sporadic neurological disease. Serological evidence suggests an association of BDV, or a related virus, with specific psychiatric diseases in humans. Here, by using a nested RT-PCR technique, we demonstrate that human BDV RNA is present in the PBMC of psychiatric patients. In an examination of a total of 60 patients from 5 wards of a hospital in Japan, the detection rate differed within each ward, ranging from 8% to > 50% (37% on the average). Of particular note was the finding that the human derived BDV sequences, which included deleted forms in about 23% of the positive samples, were slightly different from those derived from horse BDV. These results suggest urgent consideration of the measures to be taken to cope with the effects of blood transfusion. In addition, the detection of a high level of BDV in the PBMC of patients will help our understanding of the pathogenesis in the disease.

Antibodies, Viral↗

Prevalence of Borna disease virus RNA in peripheral blood mononuclear cells from blood donors.

The presence of Borna disease virus (BDV) in peripheral blood mononuclear cells (PBMC) of 100 blood donors from Sapporo and 72 blood donors from Tokyo was examined using nested reverse transcriptase/polymerase chain reaction amplification with specific-primers for BDV p24. Anti-BDV p24 antibodies in the plasma of the 100 blood donors from Sapporo also were studied by enzyme-linked immunosorbent assay and by Western blot. BDV RNA was detected in 3 (4.2%) of the 72 PBMC samples from Tokyo, and in 5 (5%) of the 100 PBMC samples from Sapporo. In contrast, anti-p24 antibodies were found in only 1 (1%) of the donors from Sapporo. These results suggest that BDV infection in humans may be more widespread than previously thought.

Adolescent↗

High susceptibility of U937-derived subclones to infection with human immunodeficiency virus type 1 is correlated with virus-induced cell differentiation and superoxide generation.

The promonocytic human leukemic cell line U937, when infected with lymphotropic human immunodeficiency virus type 1 (HIV-1), becomes a continuous virus producer. A total of 46 U937-derived subclones in suspension was isolated and classified into three (2 high, 42 middle, and 2 low) types based on their susceptibility to the infection. By analyzing subclones before infection, we found that the high-type subclones expressed LFA-1 antigens at a relatively low level. In addition, the ability of these subclones to induce adherence after exposure to phorbol 12-myristate 13-acetate (PMA) was reduced. In contrast, a transition by HIV-1 infection to adherent macrophage-like cells was induced only in the high-type, but not in the low-type subclones. The high-type adherent cells obtained by HIV-1 infection were followed by further lineage to become retrodifferentiated suspension cells showing reduced syncytia formation ability. Superoxide was generated in the high-type subclones, without PMA-mediated differentiation, from the early stage of infection before HIV-1 replication, as well as during undifferentiated, differentiated and retrodifferentiated stages. In contrast, it was only transiently generated at acute phase of HIV-1 replication in low-type subclones. Long-term culture of the low-type subclones decreased the expression of major structural viral protein Gag and also virus production. Thus, the mechanism by which PMA differentiates U937 cells is not the same as that induced by HIV-1 infection. The latter mechanism results in high susceptibility to infection. The HIV-1 phenotypes of finally obtained persistently infected cells were also affected by the cell stages at the time of infection.

Cell Cycle↗

Viral activation from latency during retrodifferentiation of U937 cells exposed to phorbol ester followed by infection with human immunodeficiency virus type 1.

To determine the mechanism underlying the human immunodeficiency virus type 1 (HIV-1) latency and its activation in monocyte/macrophage lineage, the human promonocytic cell line U937 was infected with HIV-1 after differentiation with varied doses of phorbol 12-myristate 13-acetate (PMA). Variously differentiated intermediate stages were generated in U937 cells in a dose-dependent manner. When these cells were infected with lymphotropic HIV-1, the kinetics of the production of HIV-1 DNA, the appearance of HIV-1 antigen-positive cells, and viral production in the conditioned media were slower at higher doses of PMA. This different susceptibility to the infection was not due to the rate of HIV-1 adsorption. Viral replication from latency in the differentiated cells was activated in proportion with the retrodifferentiation observed in long-term cultures of the host cells. Thus, our data demonstrate the close correlation between the regulation of HIV-1 replication and the differentiation stage of monocyte/macrophage lineage cells at the time of HIV-1 infection. The retrodifferentiation phenomenon in infected cells seems to be particularly important for understanding the mechanisms for HIV-1 activation from latency.

Base Sequence↗

Demonstration of Borna disease virus RNA in peripheral blood mononuclear cells from healthy horses in Japan.

Borna disease (BD) is a progressive poliomeningoencephalomyelitis which occurs naturally in horses and sheep. Here, peripheral blood mononuclear cells (PBMC) derived from 57 healthy horses in Japan were examined by a nested reverse transcription-polymerase chain reaction to determine the prevalence of BD virus (BDV) infection. Seventeen (29.8%) of the samples were positive by this examination and the specificity of the amplified product was confirmed by hybridization with authentic oligomer probes. About 60% of the BDV RNA-positive individuals also showed seropositivity by Western blotting. This report is the first for the demonstration of BDV RNA in PBMC of healthy horses, as well as the first on the BDV infection in horses in Japan. Thus, BDV may be more widespread in healthy horses over the world as well as in Japan and the detection of BDV RNA in PBMC at a high rate indicates that the disease might develop in a part of the carriers only after long-incubation period.

Animals↗

Maintenance of high virus load even after seroconversion in newborn cats acutely infected with feline immunodeficiency virus.

The viral loads in adult and newborn cats have been compared following injection with feline CD4+ FeL-039 line cells acutely infected with feline immunodeficiency virus (FIV). The level of virus genome in peripheral blood mononuclear cells (PBMC) increased progressively despite seroconversion in the newborn cats, whereas the virus genome was apparently cleared after seroconversion in the adult cats. Immunohistochemical staining of thymus of the FIV-infected newborn cats showed clusters of viral antigen-positive cells. These results indicate that FIV infection of the newborn cat results in higher virus loads than infection of the adult cat. We discuss these findings in relation to FIV as a model system for studies of the infection of neonates with an immunosuppressive retrovirus.

Acute Disease↗

Superinfection of a defective human immunodeficiency virus type 1 provirus-carrying T cell clone with vif or vpu mutants gives cytopathic virus particles by homologous recombination.

The partially CD4-expressing T cell clone, Vpr-1, which carries a latent vpr-defective HIV-1 genome and expresses HIV-1 Nef protein only, was permissive to superinfection by HIV-1. Superinfection of Vpr-1 with vif- or vpu-defective mutants, which were noncytopathic, reactivated the vpr-defective virus and led to homologous recombination and cytopathogenesis. The data provide an experimental model for homologous recombination being an important mechanism whereby HIV-1 acquires genetic heterogeneity, and when occurring among defective virus in vivo bestows novel biological activities and virulence.

CD4-Positive T-Lymphocytes↗

Naturally occurring accessory gene mutations lead to persistent human immunodeficiency virus type 1 infection of CD4-positive T cells.

Proviral DNA from cells surviving severe but transient cytopathic effects, mediated by infection with recombinant human immunodeficiency virus type 1 (HIV-1) carrying a single gene mutation at vif, vpr, or vpu, was characterized by use of HIV-1-specific primer pairs in a two-step PCR. Deletion mutations were detected in a region that spanned the vif and vpr open reading frames. Cloning and sequencing of the amplified DNA from this region revealed frequent large deletions in a limited number of nucleotide positions. Analyses of the deletions suggested that (i) genetic recombination, (ii) template-primer slippage, and (iii) misalignment of the growing point during reverse transcription of the HIV-1 genome might be the mechanisms that generated the mutations. Apart from the large deletions, smaller deletions that gave frameshift mutations in vif and/or vpr prevailed. In addition, cells infected with a triple mutant defective in vif, vpr, and vpu did not show any cytopathic effect. Thus, mutations generating multiple accessory gene defects during HIV-1 replication correlate with viral persistence and loss of cytopathogenicity.

Base Sequence↗

Antiallergic constituents from oolong tea stem.

The antiallergic constituents of oolong tea stem were examined. The stem extracts inhibited the 48 h homologous passive cutaneous anaphylaxis (PCA) reactions or rats in a dose-dependent manner and showed the same extent of inhibitory activity as ketotifen. All antiallergic constituents from the stem were concentrated into chloroform and ethyl acetate fractions, when extracted by various solvents. These fractions were treated with polyvinylpolypyrrolidone (PVPP), which resulted in the elimination of antiallergic activity in the ethyl acetate fraction, suggesting that one of the antiallergic constituents may be tea catechins. Then, six kinds of catechins, (-)-epigallocatechin gallate (EGCG), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECG), -epicatechin (EC), (+)-catechin (C) and (-)-gallocatechin gallate (GCG), were isolated from the ethyl acetate fraction, and the inhibitory activity of these catechins on histamine release from rat peritoneal mast cells passively sensitized with anti-egg albumin (EA) IgE antibody was investigated. Among these catechins, significant inhibitory activity was observed in all the catechins except for EC. In addition, the inhibitory activity of GCG was greater than that of EGCG, which is well known to be an antiallergic constituent in tea. These results suggest that GCG may be a novel antiallergic constituent among tea catechins, and also the most potent.

Animals↗

Relationship of pesticide spraying to signs and symptoms in Indonesian farmers.

OBJECTIVES: This study assessed correlations between exposure to pesticides and signs and symptoms of pesticide toxicity among Indonesian farmers. METHODS: Detailed observations were recorded of spray frequency and pesticide handling, dermal exposure, and the chemicals used. Symptoms of acute illness were reported by the farmers, and signs of poisoning were observed by the interviewers at the time of spraying or within a few hours after it. RESULTS: The spray practices substantially exposed the farmers to pesticides. Signs and symptoms occurred significantly more often during spraying than during nonspraying seasons. Twenty-one percent of the spray operations resulted in three or more neurobehavioral, respiratory, and intestinal signs or symptoms. The number of spray operations per week, the use of hazardous pesticides, and skin and clothes being wetted with the spray solution were significantly and independently associated with the number of signs and symptoms. A dose-effect relationship was found between the neurobehavioral signs and symptoms and the use of multiple organophosphates. CONCLUSIONS: For farmers in the tropics, fully protective garb is too hot and too costly to maintain; farmers thus accept illness as a necessity. Integrated pest management has previously been demonstrated to reduce pesticide use with no loss of crop yield. The frequency of spraying should be reduced through widespread training in integrated pest management, and also the licensing and sale of the most hazardous pesticides should be regulated.

Adult↗

Comparison of plasma total plasmin activities in male and female hypertensive rats.

Plasma total plasmin activity in spontaneously hypertensive rats (SHR) was lower than in normal Wistar rats, and in male SHR, plasmin activity was higher than that in females. However, this sex-related difference in SHR was less than that observed in our previous study in normal Wistar rats. Furthermore, we and others have reported higher levels of coagulant functions in male than in female rats. These studies were taken to indicate that there is a greater necessity for higher fibrinolytic activity in males than in females. The results of the present study suggest that hypertension is a risk factor of thrombosis in view of the increased fibrinolytic activity, and in SHR there is also a sex-related difference in plasma total plasmin activity.

Amino Acid Sequence↗