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Biomedical subjects

M Naito

Publications and source records attributed to M Naito.

At least 361 records · Page 20Linked to original sources
PubMed1994

Amyloid bone cysts of the femoral neck. Impending fractures treated by curettage and bone grafting.

We performed curettage and bone grafting of amyloid cysts of the femoral neck in five patients on long-term haemodialysis. All had had hip pain on weight-bearing. The duration of haemodialysis before the operation averaged 15 years and the average age of the patients was 53 years. All the large cystic lesions were located in the anterosuperior quadrant of the femoral neck. At operation, they were found to consist of fibrous tissue containing amyloid deposits. Postoperatively, all five patients had painless hips and the grafts had incorporated into the bone defects.

Adult↗
PubMed1994

[A clinicobacteriologic study on sultamicillin fine granules in pediatric sinusitis].

We carried out clinical and bacteriological studies on sultamicillin (SBTPC) in pediatric sinusitis at 10 general practice settings. The results are summarized as follows. 1. The major isolated organisms from purulent nasal discharges were Streptococcus pneumoniae 27.5%, Haemophilus influenzae 32.4% and Moraxella catarrhalis 9.9%. Similar results were observed for the major isolates from nasopharynx. 2. 33% of the isolated S. pneumoniae were penicillin-insensitive S. pneumoniae (PISP) against which the MICs were equal to or higher than 0.1 microgram/ml. 3. PISP was isolated from 14% of all cases. 4. The clinical efficacy rate was 77.5% and was deemed satisfactory. 5. In the bacteriological study, persistence rate of PISP was 38.5% among the PISP from purulent nasal discharge and 60.0% among the PISP from nasopharynx which and these values were significantly higher than persistence rates of PSSP, H. influenzae and M. catarrhalis. 6. Adverse reactions were observed in 21.5% of all cases, involving diarrhea and loose stool.

Ampicillin↗
PubMed1994

Serum hepatitis C virus RNA levels and liver injury in volunteer blood donors.

OBJECTIVES: Liver histology in volunteer blood donors positive for serum hepatitis C virus RNA was investigated in relation to hepatitis C virus viremia levels. METHODS: Twenty-one volunteer blood donors positive for serum hepatitis C virus RNA by polymerase chain reaction were monitored for at least 1 yr by monthly routine liver function tests and underwent liver biopsy. Liver histology findings were correlated with hepatitis C virus viremia levels assessed by a quantitative branched DNA assay. RESULTS: Liver histology showed the features of chronic hepatitis in 20 (95%) patients. Only one of the seven patients with persistently normal aminotransferase levels during follow-up had normal liver histology, and the others had chronic hepatitis. Sera obtained the same day of the liver biopsy were shown to contain hepatitis C virus RNA of 10(5.7)-10(7.6) equivalent/ml (median 10(6.7)). The total histological activity index score (median 2, range 0-15) and the scores of portal inflammation (median 1, range 0-3), lobular inflammation (median 1, range 0-4) and piecemeal necrosis (median 0, range 0-5) correlated with viremia levels (r = 0.64, p < 0.01; r = 0.60, p < 0.01; r = 0.48, p < 0.05; and r = 0.49, p < 0.05, respectively). CONCLUSIONS: These findings suggest that chronic hepatitis is frequently caused by hepatitis C virus infection irrespective of the serum aminotransferase levels, and high level hepatitis C virus replication is a contributory cause for liver injury in volunteer blood donor populations.

Alanine Transaminase↗
PubMed1994

Serum hepatitis C virus RNA quantity and histological features of hepatitis C virus carriers with persistently normal ALT levels.

We studied hepatitis C virus carriers with normal liver function to evaluate the histological features of their livers and the replicative levels of hepatitis C virus. Liver biopsies were performed in 22 hepatitis C virus carriers with persistently normal ALT levels. Hepatitis C virus RNA in serum was quantified with a competitive assay that combined reverse transcription and the polymerase chain reaction, which is based on co-amplification of the target RNA with known amounts of synthetic mutated RNA. Three patients had normal livers on histological study, whereas the other 19 had chronic persistent hepatitis, with lymphoid infiltrates or aggregates in portal tracts commonly observed but intralobular inflammatory changes absent or minimal. The titer of hepatitis C virus RNA (logarithmic transformed copy number per milliliter of serum) varied from 4.0 to 8.0 (mean +/- S.D.: 6.3 +/- 1.1); it was significantly lower in the three patients with normal livers (4.3 +/- 0.2) than in those with chronic persistent hepatitis with mild (6.4 +/- 0.8, n = 11) or moderate (7.1 +/- 0.5, n = 8) portal inflammation. The titer of hepatitis C virus RNA was correlated with the total score (r = 0.68) and the score for portal inflammation (r = 0.68) in the histological activity index. These results indicated that there seem to be "healthy carriers" of hepatitis C virus with extremely low levels of viral replication. However, in most hepatitis C virus carriers with persistently normal ALT levels, there are inflammatory changes in the portal tracts, with severity depending on the replicative levels of hepatitis C virus.

Adolescent↗
PubMed1994

Ultrastructure of macrophages and dendritic cells in osteopetrosis (op) mutant mice lacking macrophage colony-stimulating factor (M-CSF/CSF-1) activity.

The ultrastructural features of macrophages and dendritic cells of mice homozygous for osteopetrosis (op/op) mutation were studied. The mutant mice are characterized by defective differentiation of osteoclasts, monocytes, and tissue macrophages due to the lack of functional macrophage colony stimulating factor (M-CSF/CSF-1) activity. In op/op mice, tissue macrophages were reduced in number and smaller than in normal littermates. Macrophages in op/op mice showed various degrees of phagocytosis but the development of intracytoplasmic organelles and microvillous projections was poor. After administration of CSF-1 daily for 2 weeks, macrophages in op/op mice developed lysosomes and microvillous projections. In the thymic medulla, T-cell zone of lymph nodes, splenic white pulp and epidermis of the op/op mice, the number of dendritic cells was similar to that in normal littermates and the dendritic cells developed a tubulovesicular system typical of interdigitating cells. Birbeck granules in epidermal Langerhans cells were detected in unmanipulated op/op mice, op/op mice injected with CSF-1, and normal littermates or control mice. However, in untreated op/op mice, dendritic cells projected shorter cytoplasmic processes than in normal littermates, normal control mice and CSF-1 injected op/op mice. These results indicate that the differentiation and maturation of tissue macrophages are mediated by CSF-1, but the dendritic cell differentiation is controlled by other factor(s) than CSF-1, most probably by GM-CSF.

Animals↗
PubMed1994

[Studies on aspoxicillin for its transfer to the skin].

To evaluate the usefulness of aspoxicillin (ASPC) in the field of plastic and reconstructive surgery, we examined its transfer to the skin. 1. After intravenous drip infusion of ASPC for 1 hour at a dose of 2 g in 13 adults and at 1 g in 2 children, the mean serum ASPC concentration 1 hour after termination of the infusion was 70.46 +/- 28.05 micrograms/ml. The mean concentration in the skin tissue 1 hour after infusion in 15 patients was 32.45 +/- 18.47 micrograms/g. The rate of transfer to the skin 1 hour after infusion in the 15 patients was 52.9 +/- 29.7%. 2. The ASPC concentrations in skin tissues and the rates of its transfer to the skin did not differ significantly between 5 patients with facial surgery and 10 with surgery in the trunk or limbs. 3. To prevent postoperative infections, ASPC was intravenously drip infused twice daily for 2 approximately 3 days after operation at a dose of 2 g in adults and 1 g in children. No postoperative infection occurred in any patient, suggesting the effectiveness of this drug. In addition, no side effects or abnormalities in clinical examination values were observed.

Adolescent↗
PubMed1994

Hip arthroplasty in haemodialysis patients.

We retrospectively reviewed 17 hip arthroplasties in 15 patients having haemodialysis for chronic renal failure. The duration of haemodialysis before the operation averaged 8.6 years and the average age of the patients was 61 years. All patients were followed for more than two years (mean 4.6 years). Six arthroplasties in four patients had failed due to loosening, and one of these patients died from undiagnosed infection of both hips at 7.6 years after the operation. General skeletal abnormalities caused by maintenance haemodialysis may explain the high incidence of loosening and it is important to be aware of the danger of postoperative infection. The risk-to-benefit ratio of hip arthroplasty is high in patients on haemodialysis.

Adult↗
PubMed1994

The role of macrophage colony-stimulating factor in hepatic glucan-induced granuloma formation in the osteopetrosis mutant mouse defective in the production of macrophage colony-stimulating factor.

To elucidate the effects of macrophage colony-stimulating factor (M-CSF) on Kupffer cells and monocyte/macrophages in hepatic granuloma formation, we examined granulomas produced by glucan injection in the liver of osteopetrotic mice and littermates with or without M-CSF administration. In the osteopetrotic mice, monocytes were deficient in peripheral blood, and their number did not increase after glucan injection. Hepatic granulomas were formed in the osteopetrotic mice by glucan injection without a supply of blood monocytes. During this process, M-CSF-independent Kupffer cells proliferated, particularly before the granuloma formation, clustered in the hepatic sinusoid, and transformed into epithelioid cells and multinuclear giant cells. In the M-CSF-treated osteopetrotic mice, glucan injection induced an increase in the number of blood monocytes and formed hepatic granulomas at a nearly similar degree to that of littermate mice. Thus, it is concluded that neither monocytes nor M-CSF are necessary for granuloma formation. In contrast, Kupffer cells play a crucial role as granulomas develop in M-CSF-uninjected osteopetrotic mice.

Animals↗
PubMed1994

[Plasma fibrinogen as a cardiovascular risk factor].

Recent prospective epidemiological studies have shown that plasma fibrinogen is a powerful, independent risk factor of arteriosclerotic diseases such as ischemic heart disease, stroke and peripheral vascular disease. Cross-sectional studies have shown correlation of fibrinogen with various factors, including age, gender, race and smoking. Plasma fibrinogen strongly affects blood coagulation, blood rheology and platelet aggregation. In addition, fibrinogen, fibrin and their degradation products have direct effects on the vascular wall. The migration of vascular smooth muscle cells from the media into the intima and their proliferation play an important role in the pathogenesis of atherosclerosis and in the organization of thrombi. Smooth muscle cells adhere to substrate-bound fibrinogen/fibrin. The cells migrate to a gradient of soluble fibrinogen (chemotaxis). The cells also migrate in a dose-dependent manner to a gradient of substrate-bound fibrinogen and fibrin (haptotaxis). The relation among hyperfibrinogenemia, atherosclerosis and thrombosis is highly complicated. There is no prospective study on fibrinogen and cardiovascular disorders among Japanese. Studying plasma fibrinogen to predict cardiovascular disorders may provide some new insight into their pathophysiological mechanisms.

Aged↗
PubMed1994

Buoyant density of hepatitis C virus recovered from infected hosts: two different features in sucrose equilibrium density-gradient centrifugation related to degree of liver inflammation.

Hepatitis C virus is reported to have a low buoyant density in sucrose. To determine the density of hepatitis C virus in the circulation of infected hosts and its association with the degree of liver inflammation, we examined serum samples from 10 patients who were positive for both hepatitis C virus antibody (C100 antigen) antibody and serum hepatitis C virus RNA. After the serum was ultracentrifuged in sucrose density gradient (10% to 60%), the hepatitis C virus RNA titer in each collected fraction was quantified by means of competitive reverse transcription-polymerase chain reaction. In samples from five blood donors, the hepatitis C virus RNA titer had a single peak at fractions with densities of 1.08 to 1.11 gm/ml. In samples from five patients with ALT abnormalities, the titer had two peaks at fractions with 1.09 to 1.10 gm/ml and 1.22 to 1.25 gm/ml. After the selected samples were treated with detergents and ultracentrifuged, the titer in the 1.08 to 1.11 gm/ml fractions decreased and that in the 1.22 to 1.25 gm fractions increased. This result implied that the hepatitis C virus density changed with removal of the viral envelope by lipid solvents. Thus the buoyant density of hepatitis C virus in sucrose was 1.08 to 1.11 gm/ml for an intact virion and 1.22 to 1.25 gm/ml for what was presumed to be a nucleocapsid. These results demonstrated that HCV virion is a dominant form in the circulation of blood donors without ALT abnormalities. In patients with liver inflammation HCV particles with higher densities of 1.22 to 1.25 gm/ml coexist with virion in the circulation, which might be presumed nucleocapsids.

Adolescent↗
PubMed1993

Presence of eight distinct homeobox-containing genes in cnidarians.

Using the polymerase chain reaction, we identified four different homeobox-containing genes in Hydra magnipapillata. Three of them, cnox1-Hm, cnox2-Hm and cnox4-Hm, were equivalent to homeobox genes that had already been identified in other species of cnidarians. cnox5-Hm was a new homeobox gene and was very similar to Mox1 in the mouse. Together with the published data, our results indicate that there are at least eight distinct classes of homeobox genes in cnidarians. These homeobox genes show a maximum of 60 to 77% identity in terms of the amino acid residues in their homeodomains to certain classes of homeobox genes that have been identified in Drosophila.

Amino Acid Sequence↗
PubMed1993

Suppression of T-lymphoma cell apoptosis by monoclonal antibodies raised against cell surface adhesion molecules.

We have previously established a mouse malignant T-lymphoma CS-21 cell line that preferentially metastasizes to lymph nodes after s.c. inoculation into BALB/c mice. The CS-21 lymphoma cells were grown in vitro in the presence of CA-12 stromal cells isolated from lymph nodes. When CS-21 cells were cultured alone, they underwent apoptotic cell death with DNA fragmentation. In contrast, the culture of CS-21 cells attached to a monolayer of CA-12 stromal cells prevented CS-21 cell apoptosis and enhanced cell proliferation. To identify the cell adhesion molecules, we developed monoclonal antibodies (mAbs) directed against CS-21 cell surface proteins. Fourteen mAbs partially inhibited the binding of CS-21 cells to a CA-12 stromal cell monolayer. MCS-5 (mAb against CS-21 No. 5) directed against a M(r) 168,000 cell membrane protein and MCS-19 against a M(r) 23,000 protein were found to suppress apoptosis and to stimulate CS-21 cell growth. Soluble factors secreted from CA-12 stromal cells enhanced CS-21 cell growth but were not sufficient to prevent apoptosis. In the presence of both stromal cell-secreted factors and mAbs MCS-5 or MCS-19, CS-21 lymphoma cells evaded apoptosis and grew as fast as in the coculture with CA-12 stromal cells. Because of these results, we conclude that CA-12 lymph node stromal cells support CS-21 lymphoma cell growth by secreting paracrine growth factors and by presenting receptors for the M(r) 168,000 and M(r) 23,000 cell surface adhesion molecules of CS-21 cells that transmit signals to prevent CS-21 cell apoptosis.

Animals↗
PubMed1993

Dendritic cell progenitors phagocytose particulates, including bacillus Calmette-Guerin organisms, and sensitize mice to mycobacterial antigens in vivo.

Dendritic cells, while effective in sensitizing T cells to several different antigens, show little or no phagocytic activity. To the extent that endocytosis is required for antigen processing and presentation, it is not evident how dendritic cells would present particle-associated peptides. Evidence has now been obtained showing that progenitors to dendritic cells can internalize particles, including Bacillus Calmette-Guerin (BCG) mycobacteria. The particulates are applied for 20 h to bone marrow cultures that have been stimulated with granulocyte/macrophage colony-stimulating factor (GM-CSF) to induce aggregates of growing dendritic cells. Cells within these aggregates are clearly phagocytic. If the developing cultures are exposed to particles, washed, and "chased" for 2 d, the number of major histocompatibility complex class II-rich dendritic cells increases substantially and at least 50% contain internalized mycobacteria or latex particles. The mycobacteria-laden, newly developed dendritic cells are much more potent in presenting antigens to primed T cells than corresponding cultures of mature dendritic cells that are exposed to a pulse of organisms. A similar situation exists when the BCG-charged dendritic cells are injected into the footpad or blood stream of naive mice. Those dendritic cells that have phagocytosed organisms induce the strongest T cell responses to mycobacterial antigens in draining lymph node and spleen. The administration of antigens to GM-CSF-induced, developing dendritic cells (by increasing both antigen uptake and cell numbers) will facilitate the use of these antigen-presenting cells for active immunization in situ.

Animals↗
PubMed1993

[MR cisternography using "long echo train length fast spin echo sequence" for demonstrating the inner ear].

Excellent quality of MR cisternography was acquired using "long echo train length fast spin echo sequence" (TR/TE = 2666/200, ETL = 24, 6 or 8 NEX, 3 mm thickness, 0 mm interslice gap, 19 cm FOV, 512 * 384, 2 DFT method). The inner ear anatomy such as canaliculus cochleae or lamina spiralis ossea were well visualized. The VII, VIII th nerve bundles within the internal auditory canal were detectable as 1 to 4 bundles. The vessels in the cerebellopontine angle or the internal auditory canal were also demarcated from the VII, VIII th nerve bundles because of their flow void. Signal to noise ratio seemed to be better than 3 DFT method, however limited spatial resolution in the cranio-caudal direction might require additional sagittal or coronal scan.

Adult↗
PubMed1993

Cloning and expression of the chicken c-kit proto-oncogene.

The Kit protein is a cell-surface tyrosine kinase receptor encoded by the c-kit proto-oncogene. cDNA clones encoding chicken Kit were isolated from a chicken brain cDNA library, and the nucleotide (nt) sequence of a cDNA clone containing the entire protein-coding region was determined. The deduced amino acid (aa) sequence of chicken Kit shows 63% identity to mouse Kit, and suggests that chicken Kit shares common structural and functional features with mouse Kit. RNA blot analysis indicated that the expression pattern of the chicken c-kit transcript in chicken organs was similar to that of mouse c-kit in mice, suggesting that chicken Kit has biological roles analogous to those of mouse Kit.

Amino Acid Sequence↗
PubMed1993

Early changes of macrophage-like immunoreactivity in the rat inferior olive after intraperitoneal 3-acetylpyridine injection.

Early changes of macrophage-like immunoreactivity were observed in the inferior olive after intraperitoneal injection of 3-acetylpyridine (3AP) using seven monoclonal antibodies recognizing macrophage subpopulations (OX-42, OX-6, ED-1, RM-1, TRPM-1, TRPM-2, and TRPM-3). Both resting and activated forms of microglia were stained with OX-42 and TRPM-2. Some of activated microglia reacted to OX-6 and/or ED-1. Neither resting nor activated microglia reacted to any of RM-1, TRPM-1, and TRPM-3. Four h after 3AP injection, the processes of OX-42-positive microglia had increased in number and became thicker than resting microglia. Between 24 h and the 7th day after 3AP injection (day 7), OX-42-positive microglia gradually increased in number. At 24 h after 3AP injection, round cells appeared that stained with all seven antibodies. These disappeared by day 3. Double staining indicated that OX-42-positive activated microglia on day 7 were divided into subpopulations by their immunoreactivity to ED-1. We suggest that the round cells derived from blood monocytes and entered the brain only transiently while OX-42-positive activated microglia originated from parenchymal resting microglia and continued to increase in number after the disappearance of the round cells.

Animals↗
PubMed1993

cDNA expression cloning of the 85-kDa protein overexpressed in adriamycin-resistant cells.

An 85-kDa cell surface protein recognized by monoclonal antibody MRK-20 was identified in adriamycin-resistant tumor cells. The expression of the 85-kDa protein has recently been reported to be associated with the differentiation of hematopoietic cells. However, the primary structure of the 85-kDa protein has not been determined. To clarify its primary structure, we carried out cDNA expression cloning of the 85-kDa protein with monoclonal antibody MRK-20. We found that the 85-kDa protein is identical to CD36 (GP VI), but at least two species of transcript exist in the tumor cells and one of these transcripts has a novel sequence at the 3'-region. The transcript with the novel sequence at the 3'-region was found to be expressed during the differentiation of hematopoietic cells.

ATP Binding Cassette Transporter, Subfamily B, Mem↗