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Biomedical subjects

K Moriya

Publications and source records attributed to K Moriya.

At least 73 records · Page 4Linked to original sources

Outbreak of acute glomerulonephritis in children: observed association with the T1 subtype of group A streptococcal infection in northern Kyushu, Japan.

Group A streptococcal infection is associated with the occurrence of acute glomerulonephritis (AGN) and rheumatic fever (RF). A surveillance study in the Saga area, in northern Kyushu, Japan, showed a small variation in the reported number of group A streptococcal infections in the period 1988-94. However, of the AGN cases reported in this period, more than half were observed in 1992. In order to examine whether some change had occurred in the serotype distribution of Streptococcus pyogenes during the period, patients in the Saga area diagnosed as having group A streptococcal infection and patients with AGN or RF were analyzed. Serological T-typing of S. pyogenes was carried out for patients with group A streptococcal infections, and the association between the occurrence of AGN or RF and the distribution of each different T subtype was analyzed. M-typing of S. pyogenes was also carried out and the correlation between T and M types was examined. From 1988 to 1994, the annual number of patients with group A streptococcal infections in the Saga area showed a small variation, range 65-100 patients/year. Of the 42 patients with AGN and three with RF observed in this period, 27 with AGN (64%) and one with RF (33.3%) were detected in 1992. Only the T1 subtype increased in 1992; the other T subtypes showed little variation in incidence. The number of patients with the T1 subtype was significantly correlated with the occurrence of AGN by regression analysis (P < 0.01). Of the 170 subjects tested for both T and M subtypes, 44 of the 45 T1-typed subjects had the M1 protein. Our epidemiological study suggested that the T1 subtype of streptococcal infection was associated with an outbreak of AGN in 1992 in the Saga area.

Acute Disease↗

[A comparative study on the efficacies of ritipenem acoxil and cefotiam hexetil in bacterial pneumonia by the double-blind method].

To objectively evaluate the efficacy, safety and usefulness of the newly developed penem oral antibiotic, ritipenem acoxil (RIPM-AC), against bacterial pneumonia, we conducted a multi-center double-blind comparative study using cefotiam hexetil (CTM-HE) as the control drug. Both RIPM-AC and CTM-HE were orally administered at 200 mg t.i.d. for 14 days, in principle. The results were as follows: The total number of patients enrolled in this trial was 208, of which 152 cases (RIPM-AC group: 73, CTM-HE group: 79) were evaluable for clinical efficacy. 1. The clinical efficacy rates (excellent + good) were 91.8% (67/73) in the RIPM-AC group and 94.9% (75/79) in the CMT-HE group. There was no significant difference between the two groups, and the clinical equivalency of RIPM-AC to CTM-HE was demonstrated. 2. In the patients enrolled in the evaluation of clinical efficacy, the eradication rates of the causative organisms were 84.6% (22/26) in the RIPM-AC group and 91.7% (22/24) in the CTM-HE group, with no significant difference between the two groups. 3. Side effects were noted in 9 cases (9.6%) of the RIPM-AC group and 5 cases (4.9%) of the CTM-HE group. Abnormal laboratory test findings were observed in 23 cases (26.7%) of the RIPM-AC group and 15 cases (15.6%) of the CTM-HE group. There was no significant differences between the two groups in the incidence of side effects nor of abnormal laboratory test findings. In the safety evaluation, RIPM-AC was judged to be safe in 64 cases (68.1%) and CTM-HE in 82 cases (80.4%), with no significant difference. 4. The usefulness rates (markedly useful+useful) were 86.5% (64/74) in the RIPM-AC group and 92.5% (74/80) in the CTM-HE group. There was no significant difference between the two groups. Since RIPM-AC showed clinical efficacy similar to those of CTM-HE and posed no particular safety problems, it is expected to be a useful antibiotic for the treatment of bacterial pneumonia.

Adolescent↗

Hepatitis C virus genotypes and development of hepatocellular carcinoma.

BACKGROUND: Among several genotypes of hepatitis C virus (HCV), genotypes 1b (or II) and 2a (or III) are predominant in Japan. Although it has been shown that the efficacy of interferon treatment of patients with chronic hepatitis C varies with the HCV genotype, the relationship between HCV genotype and the development of hepatocellular carcinoma (HCC) has not been well described. METHODS: The genotypes and serum levels were determined for HCV-RNA in 72 patients with HCC and 131 patients without HCC, all of whom were positive for second-generation HCV antibody and HCV-RNA. In addition, clinical data from 34 patients with HCC who each had a history of blood transfusion were analyzed. RESULTS: Fifty-seven (79.2%) of 72 patients with HCC had genotype 1b HCV, whereas 101 (77.1%) of 131 patients without HCC had genotype 1b, indicating that there was no significant difference in the prevalence of genotype 1b HCV between the patients with and without HCC. Furthermore, comparison of patients with HCC with genotype 1b HCV with those with genotype 2a who had a history of blood transfusion did not differ significantly in the number of years from blood transfusion to diagnosis of HCC. Levels of HCV-RNA were not significantly different among patients with liver diseases of various stages. CONCLUSIONS: Hepatocellular carcinoma develops in patients with either genotype 2a HCV or genotype 1b HCV. A difference in genotype is not likely to be responsible for the difference in development of HCC.

Carcinoma, Hepatocellular↗

Dominant replication of either virus in dual infection with hepatitis viruses B and C.

To characterize the state of dual infection with hepatitis B virus (HBV) and hepatitis C virus (HCV), HBV-DNA and HCV-RNA levels were determined by spot hybridization or polymerase chain reaction in the sera of patients who were positive for both hepatitis B surface antigen and HCV antibody. Among 27 patients who showed evidence of double infection, 21 (77.8%) had detectable levels of only either HBV or HCV genome in their sera, 2 (7.4%) showed none of the viral genomes, and 4 (14.8%) had both HBV-DNA and HCV-RNA. In the 4 patients with both HBV-DNA and HCV-RNA, the titers of HCV-RNA or HBV-DNA were lower than those in the patients with HCV-RNA or HBV-DNA alone. In some patients with chronic hepatitis, the viruses appeared to replicate in turn in the course of the disease. These results indicate that the viruses show alternating dominance in replication in most of the patients who have dual infection with HBV and HCV, probably due to interference of the viruses.

Adolescent↗

Nucleus-cytoplasm interactions causing reproductive incompatibility between two populations of Tetranychus quercivorus Ehara et Gotoh (Acari: Tetranychidae).

Partial reproductive incompatibility between two local populations of Tetranychus quercivorus Ehara et Gotoh derived from Sapporo (43 degrees N) and Tsukuba (36 degrees N), Japan, was found. The incompatibility was unidirectional: the Sapporo female was incompatible with the Tsukuba males, which resulted in a low egg hatchability and strongly male-biased sex ratio, whereas the reciprocal cross was compatible and produced normal progeny with a female-biased sex ratio. To determine the genetic mechanism responsible for the incompatibility, crosses were made between the two populations over five to six filial generations as well as backcrosses. The results suggested that the incompatibility could be caused by an interaction between the cytoplasm from the Sapporo population and a single nuclear gene from the Tsukuba population. Compatibility was not restored when individuals of the Sapporo population were treated with antibiotics or high temperature, indicating a possibility that the cytoplasmic factors are cytoplasmically inherited elements such as mitochondria rather than microorganisms.

Animals↗

Expression of hepatitis C virus envelope proteins in transgenic mice.

In an attempt to establish a model for hepatitis C virus (HCV) infection, we produced mice transgenic for the HCV envelope genes, E1 and E2, under the control of a regulatory element from hepatitis B virus. F1-generation mice from the established founders demonstrated expression of both E1 and E2 proteins as glycosylated forms in their organs including the liver. Immunostaining revealed the localization of envelope proteins principally in the cytoplasm of hepatocytes around the hepatic central veins. Furthermore, E1 and E2 proteins were shown by immunoprecipitation to be associated with each other in the mouse liver. There was no evidence of tissue pathology in the mouse liver up to 16 months of age, suggesting that E1 and E2 proteins per se may not have direct pathogenic effects. Our results demonstrate the first successful expression of HCV gene products in the mouse liver and the association of in vivo expressed HCV envelope proteins. This transgenic mouse would be a good model to study the virus-cell interactions of HCV such as intracellular transport and assembly of envelope proteins. Also it may be a good model system to determine the role of these proteins in the pathogenesis of hepatitis or extra-hepatic manifestations in HCV infection by the introduction of cytotoxic T lymphocytes specific for the envelope proteins.

Animals↗

Degradation of polyaromatic hydrocarbons by organic solvent-tolerant bacteria from deep sea.

We isolated three organic solvent (OS)-tolerant bacterial strains DS-1051, DS-1902, and DS-313 from a depth of 1,168 m in Sagami Bay, Japan. These isolates were tolerant to various kinds of toxic OSs such as benzene, toluene, and p-xylene. They also could degrade polyaromatic hydrocarbons, naphthalene or biphenyl, in a medium-OS (9:1) two-liquid-phase system. Percentage degradation of polyaromatic hydrocarbons in OS by these strains were higher than those obtained from cultures in which substrates were in the medium without OS.

Bacteria↗

Effects of natural human interleukin-6 on thrombopoiesis and tumor progression in tumor-bearing mice.

The growth of inoculated colon 26 adenocarcinoma (colon 26) in mice gradually increased the platelet count owing to murine IL-6 secreted from the tumor, while Lewis lung carcinoma (LLC) decreased the platelet count in the hosts, depending on the tumor growth. Natural human IL-6 injections (hIL-6), 280 micrograms/kg/day, stimulated the platelet production in both types of carcinoma-bearing mice. When the administration of mitomycin C or cisplatin decreased the platelet number as a side reaction with a concomitant of suppressing the growth of colon 26 and LLC, respectively, hIL-6 could also increase the platelet count without the augmentation of tumor growth. However, loss of carcass weight was observed in colon 26-bearing mice treated with hIL-6, suggesting the development of cachexia is associated with hIL-6 administration. Despite the possibility of inducing cachexia in some types of tumors, our results suggest that IL-6 could be a useful means of restoring the decreased platelet number in cancer patients after intensive chemotherapy.

Adenocarcinoma↗

Induction of interstitial pneumonitis during interferon treatment for chronic hepatitis C.

A 48-year-old woman developed interstitial pneumonitis while receiving interferon treatment for chronic hepatitis C. Laboratory studies prior to treatment showed elevated serum alanine aminotransferase levels, but chest X-rays and physical examination revealed no abnormalities suggestive of interstitial pneumonitis. At the 9th week of interferon treatment (total dose, 380 MU of recombinant interferon-alpha, without other medications), the patient began to complain of cough and exertional dyspnea. A chest X-ray film revealed diffuse reticulo-nodular shadows in bilateral lung fields, suggesting a diagnosis of interstitial pneumonitis. A marked increase in lymphocyte count was observed in bronchoalveolar lavage fluid and a diagnosis of interstitial pneumonitis was made as a result of transbronchial lung biopsy. Her clinical symptoms and abnormal lung shadows were reversible, improving within a month of the discontinuation of interferon, and disappearing promptly after exogenous corticosteroid was instituted. This may be the first case of drug-induced interstitial pneumonitis occurring during the course of treatment with interferon alone. We should be aware of the possibility of interstitial pneumonitis developing during treatment of chronic hepatitis C with interferon.

Biopsy↗

Cutaneous arterial fibromuscular dysplasia: a case report and electron-microscopic study.

A case of a 39-year-old female with fibromuscular dysplasia (FMD) manifesting subcutaneous pulsatile nodules on the right side of her forehead and on her right wrist is reported here. These nodules proved to be FMD aneurysms of the frontal ramus of the right superficial temporal artery and the right radial artery. The patient had also suffered a stroke with subarachnoidal bleeding as a result of this disease. Angiographic examination showed aneurysms in the union and the bilateral vertebral arteries, a branch of the right renal artery, and one the right lumbar artery. A biopsy specimen taken from the frontal branch of the right superficial artery revealed segmental intimal thickening consistent with intimal fibroplasia type FMD upon histological examination. Electron-microscopic findings were also discussed in connection with the histogenesis of the disease. This appears to be the second case of FMD involving arteries in the skin to be reported in the dermatological literature.

Adult↗

Induction of cell cycle progression by hepatitis B virus HBx gene expression in quiescent mouse fibroblasts.

The HBx gene of hepatitis B virus has been shown to induce hepatic tumors in transgenic mice and is implicated in hepatocarcinogenesis in human hepatitis B virus infection. To further characterize the role of HBx gene in carcinogenesis, we established mouse fibroblast cell lines in which the expression of HBx gene could be controlled by glucocorticoid hormone and examined the effect of HBx gene expression on cell growth in vitro. Along with the expression of HBx gene, most cells in the G0/G1 phase moved into the S phase in 24 h, and the cell cycle progressed further toward 48 h. Induction of DNA synthesis was also demonstrated by bromo-deoxyuridine labeling analysis. These results indicate that HBx gene has a function to trigger the synthesis of cellular DNA and suggest that HBx gene may play a role in hepatocarcinogenesis in human infection by driving deregulated cell cycle progression.

3T3 Cells↗

Preparation of organic solvent-tolerant mutants from Pseudomonas aeruginosa strain PAO1161.

Most organic solvents (OSs) are toxic and inhibit growth of microorganisms even at low concentrations. Therefore, they are used to sterilize microbial cultures and to maintain solutions in a sterile condition. However, the physiological basis of such phenomenon is poorly understood. Although there are some microorganisms that can utilize a number of OSs as their sole carbon and energy sources, OSs must be provided as a vapor or at a very low concentration to avoid growth inhibition.

Drug Tolerance↗

High-level expression of hepatitis B virus HBx gene and hepatocarcinogenesis in transgenic mice.

We studied the development of liver tumors in male HBx gene transgenic mice. Of two lineages studied, in the lineage with the lowest HBx gene expression liver tumors developed only in an incidence comparable with that in normal CD-1 strain, whereas 84% of male mice with a high level of the HBx gene product succumbed to liver neoplasia, indicating that continued HBx gene expression higher than a certain threshold level may be necessary for the development of hepatic neoplasia. Sixty-five mice from a lineage with a high level of HBx expression were then followed throughout their 24-mo lifespan. The livers of transgenic mice showed foci of cellular alteration with cytoplasmic vacuolations around the central veins from the age of 2 mo, but these foci did not expand progressively by the age of 12 mo. Immunostaining demonstrated such hepatocytes had higher expression of HBx protein than surrounding cells. Neoplastic lesions including liver cell adenomas and hepatocellular carcinomas developed from the age of 13 mo. By bromodeoxyuridine labeling analysis, hepatocytes in altered foci were found to have increased DNA synthesis, whereas no labeling was observed in age- and sex-matched nontransgenic littermate controls. Furthermore, DNA content analysis revealed the existence of several small aneuploid peaks in the transgenic liver before the age of tumor development. These results suggest that the continued expression of HBx gene may initiate a complex process to hepatocellular carcinoma by inducing DNA synthesis and placing large numbers of hepatocytes subjective to secondary events for transformation.

Adenoma, Liver Cell↗

Biofeedback therapy in the treatment of tinnitus.

Seven patients were treated with electromyographic biofeedback therapy for intractable tinnitus which was supposed to be reinforced by mental distress and muscle tension. Three patients, who succeeded in decreasing electromyographic levels of the frontal muscle, were able to reduce tinnitus and relieve anxiety. One patient could eliminate tinnitus only during biofeedback sessions, but the efficacy was not continuous in daily life. The other three patients, who failed to decrease electromyographic levels, did not obtain favorable results. It is suggested that biofeedback therapy appears to be of greatest benefit when muscle tension and mental distress are the cause of magnification of the tinnitus symptoms.

Acute Disease↗

Bilateral carcinomas of the maxillary sinus.

We report a 68-year-old male with a rare case of synchronous bilateral carcinomas of the maxillary sinus. A CT scan revealed a large tumour mass that extruded from the left maxillary sinus; tissue of soft density filled the right antrum which had intact bony walls. A probe antrostomy on the right side disclosed a tumour which was diagnosed histologically as the same poorly differentiated squamous cell carcinoma as that in the left antrum. The incidence and aetiology of this disorder are presented, and its diagnosis and management are discussed.

Aged↗

Ultrastructure of the chick vestibular ganglion and vestibular nucleus. A scanning electron microscopic study.

The fine structure of the chick vestibular ganglion and vestibular nucleus was studied in three dimensions using a scanning electron microscope (SEM). NaOH and OSO4 maceration methods were applied to observe the configuration in the mechanically torn specimens. Also, Tanaka's aldehyde prefix OSO4-DMSO-OSO4 method (A-O-D-O method) was applied to observe the intracellular structure in the fractured specimens. The surface of the ganglion cell and the nerve processes were seen to be covered with abundant thin fibrous tissues in the specimen treated with OSO4 maceration. This surface fibrous tissue was completely removed with the NaOH maceration method. As a result, the ganglion cell and nerve processes could be seen to be enveloped in the myelin sheath. In the fractured vestibular ganglion treated by the A-O-D-O method, there were three patterns of perikaryal myelination in the vestibular ganglion cells: heavily myelinated, lightly myelinated, and unmyelinated, respectively. In the perinuclear region of the vestibular ganglion cell, well developed and aggregated cytoplasmic organelles such as endoplasmic reticulum, mitochondria, and Golgi apparati were observed. In the perinuclear region of the Schwann cell relatively large mitochondria were characteristically observed. In the fractured view of the vestibular nerves, most of vestibular fibers were compactly myelinated. In the vestibular nucleus, the gathering of the neuronal cells were observed with the NaOH maceration method.

Animals↗