Biomedical subjects
Publications and source records attributed to T Miyazawa.
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Infectivity of feline immunodeficiency virus (FIV) in feline and human lymphoblastoid cell lines was examined using homogeneous populations of FIV derived from infectious molecular clones of strains TMZ and Petaluma, and two recombinant chimeric clones carrying gag, pol, vif and ORF-A from the heterologous virus. FIV from the clones with the env region of the Petaluma strain was shown to infect and establish provirus in a human lymphoid cell line (MOLT-4), although the FIV-infected cells did not produce any infectious viruses. By treatment of the infected MOLT-4 cells with a phorbol ester, infectious virus was rescued. To examine which stage of the life-cycle of FIV is blocked in these cells, we analysed transcription of FIV-14 in the cells by RT-PCR. FIV-specific RNA expression could not be detected. These results strongly suggest that latency of the virus in MOLT-4 cells is due to a failure in transcription.
We report the nucleotide sequence and genetic diversity of part of the envelope (env) gene of four strains of feline immunodeficiency virus (FIV) isolated from Argentine domestic cats. The DNA encoding the V3 to V5 regions of the env gene of the FIV isolates were amplified by PCR, cloned and sequenced. Phylogenetic analysis revealed that the Argentine isolates did not cluster into a single group; one isolate clustered with subtype B FIV isolated in the USA and Japan, whereas the others formed a new cluster of FIV which might represent a prototype sequence for subtype E.
To examine the roles of auxiliary genes and the AP-1 binding site in the long terminal repeat of feline immunodeficiency virus (FIV) in vivo, three mutant viruses, which are defective in the vif gene ([delta]vif), ORF-A gene (deltaORF-A), and AP-1 binding site (deltaAP-1), and wild-type virus as a positive control were separately inoculated into three specific-pathogen-free cats. These cats were assessed by measuring the number of proviral DNA copies in peripheral blood mononuclear cells (PBMCs), the CD4/CD8 ratio and antibody responses to FIV for 16 weeks and then examining histological changes at necropsy. Although viral DNAs were detected in PBMCs from all 12 cats to various degrees until 16 weeks postinoculation, no virus was recovered from PBMCs of cats infected with (delta)vif virus during the observation period. However, a very weak antibody response was induced in one cat infected with the (delta)vif virus. In contrast, despite the successful recovery of virus from both groups of cats infected with deltaORF-A and deltaAP-1 virus, antibody responses and decrease in the CD4/CD8 ratio in the groups were milder than those in cats infected with wild-type virus. Furthermore, the numbers of proviral DNA copies in PBMCs from the two groups were not able to reach the level in cats infected with wild-type virus during the observation period. From these results, we conclude that these mutant viruses are still infectious for cats but failed in efficient viral replication and suggest that these auxiliary genes and enhancer element are important or essential to full viral replication kinetics and presumably to full pathogenicity during the early stage of infection in vivo.
Eustachian tube (ET) function was studied by means of sonotubometry and tubotympano-aerodynamography (TTAG) prior to and following exposure to hypobaric or hyperbaric conditions. Forty normal adults were subjected to hypobaric pressure. Fifty adults who underwent hyperbaric oxygen (HBO) therapy also were studied. Following hypobaric exposure, 14 of 80 ears (17.5%) exhibited middle ear barotrauma. Following hyperbaric exposure, 34 of 100 ears (34%) exhibited middle ear barotrauma. Dysfunction of the ET, characterized by altered active and passive opening capacity, was more prevalent following exposure to extremes in atmospheric pressure compared to baseline. The ET function, which was impaired after the first HBO treatment, improved gradually over the next 2 hours. Overall, however, ET function was worse after the seventh treatment. The patients who developed barotrauma exhibited worse ET function prior to hypobaric or hyperbaric exposure. Thus, abnormal ET function can be used to predict middle ear barotrauma prior to exposure to hypobaric or hyperbaric atmospheric pressure.
Novel quinoxaline 1,4-dioxide derivatives were synthesized from benzofuroxans and the enolic form of 1,3-diketones or 3-oxoalkanoic esters or 3-oxoalkanamides or butanedioic esters catalyzed by silica gel or molecular sieves and their antibacterial activities were evaluated. As the results of antibacterial screening tests in vitro, quinoxaline 1,4-dioxides revealed strong activities against Bacteroides fragilis.
The development of virus neutralizing (VN) antibody is one of the most effective host defense mechanisms against virus infection. In the present study, we developed a new VN assay against feline immunodeficiency virus (FIV) using a feline T-lymphoblastoid cell line, MYA-1 cells, based on inhibition of viral reverse transcriptase production. This assay is applicable to strains of FIV which can not infect CRFK cells. By using the assay, we examined long-term responses of VN antibody in cats experimentally infected with FIV. VN antibody titers increased progressively during first 30 weeks post inoculation and remained at high titers thereafter for 7 years of observation periods.
Forty-five mutant male ODS rats, unable to synthesize ascorbic acid, were fed nine diets containing 5, 50 or 250 mg of vitamin E/kg diet and 150, 300 or 900 mg of vitamin C/kg diet for 21 days. The concentrations of vitamins C and E increased in liver and plasma in relation to the level of these vitamins in the diet. Vitamin C dietary supplementation increased the plasma vitamin E content at low levels of vitamin E intake, supporting the concept of an in vivo synergism between both antioxidant vitamins. Vitamin C, at the dietary levels studied, did not affect the lipid peroxidation. Vitamin E decreased liver and plasma endogenous levels of thiobarbituric acid-reactive substances and liver sensitivity to non-enzymatic lipid peroxidation. This was confirmed by a highly specific assay of lipid hydroperoxides using high performance liquid chromatography with chemiluminescence detection. The hepatic concentration of both phosphatidylcholine and phosphatidylethanolamine hydroperoxides decreased as the vitamin E content of the diet increased. The results show for the first time the capacity of vitamin E to protest against peroxidation of major phospholipids in vivo under basal unstressed conditions.
Graded amounts (0, 50, 500 and 5,000 mg/liter) of ascorbic acid (AsA) were given in drinking water to guinea pigs for 21 days to prepare AsA-deficient, low-AsA, moderate-AsA and excess-AsA animals, and the plasma phospholipid hydroperoxide level and lipid concentration were quantitatively determined to investigate the antioxidant effect of AsA in vivo. Phosphatidylcholine hydroperoxide (PCOOH) was a predominant phospholipid hydroperoxide present in the plasma, and the PCOOH concentration was significantly higher in AsA-deficient, low-AsA and excess-AsA animals (80.4 nM, 54.8 nM and 42.2 nM, respectively) as compared with that in moderate-AsA animals (27.2 nM). Hyperlipidemic plasma characterized as high cholesterol and high triacylglycerol concentrations was confirmed in AsA-deficient animals. Molar ratios of plasma AsA and alpha--tocopherol against 10(4) moles of phospholipids were significantly lower in AsA-deficient and low-AsA animals (0.6-2.1 and 5.5-8.5, respectively) than in moderate-AsA and excess-AsA animals (14.2-18.0 and 11.2-11.9, respectively). In plasma, a high correlation coefficient (r = 0.979) was observed between PCOOH and AsA for which there was optimum AsA level to keep the low PCOOH and such correlation was stronger than that (r = 0.558) observed with alpha-tocopherol. The results indicated that AsA has an important function to control the phospholipid hydroperoxide level in plasma and that moderate supplementation of AsA is required to reveal its optimal antioxidant effect in vivo. The present study also showed that AsA-deficiency especially invites an increase in plasma PCOOH together with a hyperlipidemic state which are risk factors in developing atherogenesis.
A 62-year-old woman visited her primary physician because of high fever and vomiting. From a chest roentgenogram miliary tuberculosis was diagnosed. Anti-tuberculosis drugs were prescribed. Mycobacterium tuberculosis was cultured from samples of sputum. Although she took drugs for 3 months, her symptoms did not resolve and back pain developed. A chest roentgenogram showed an egg-sized mass in the posterior part of the mediastinum. Examination of a chest CT scan showed that the mass was an aortic aneurysm. A graft replacement was done, and histologic examination of the resected specimen showed that it was a tuberculous aneurysm of the descending aorta. Her symptoms disappeared, and she recovered fully. Tuberculous aneurysms are rare: they account for only 0.3% of all aneurysms. This is only the 9th reported case of tuberculous aneurysm successfully treated with surgery in Japan. We must realize that aneurysms are life-threatening complication of miliary tuberculosis.
PURPOSE: To investigate changes in blood pressure during intracarotid injection of contrast material. METHODS: Two catheters were inserted into the ipsilateral common carotid artery of dogs. The proximal catheter was used for injection of contrast material and the other was positioned distally to monitor blood pressure. RESULTS: Distal intracarotid pressure rose significantly during injection of contrast material at all rates (5, 7, and 10 mL/s) and at all doses (0.2, 0.5, 0.7, and 1.0 mL/kg). In addition, these blood pressure elevations were shown to be correlated with injection rates and doses. Even when the pressure-monitoring coaxial catheter was advanced into smaller arteries, no decline in the impact of injection was observed. CONCLUSION: Intracarotid injection of contrast material causes a temporal elevation of cerebral blood pressure in dogs.
In two patients with pulmonary alveolar proteinosis, PaO2 was normalized by massive bronchoalveolar lavage (BAL). Patient 1: A 29-year-old man presented with exertional dyspnea and a PaO2 of 57.8 mmHg. After four BALs, the PaO2 was 106.4 mmHg. For ten years thereafter he has been doing well. Patient 2: A 58-year-old women presented with extertional dyspnea and a PaO2 of 64.4 mmHg. The PaO2 increased to 110.6 mmHg after four BALs. BAL required much skill, but it is one of the most effective methods for the treatment of pulmonary alveolar proteinosis. Because this condition is related to an interstitial process, these two patients need to be followed carefully.
The present study was carried out to determine the correlation between the efficacy of macrolide therapy and clinical features of chronic sinusitis. We performed an immunohistological study of subepithelial inflammatory cells in the paranasal mucosa from the patients of chronic sinusitis treated with low-dose, long-term administration of macrolides, and obtained the following results. 1) Many IgA and IgE positive cells were observed in subepithelial area, while IgG and IgM positive cells were sparse. 2) The cases with many IgA positive cells in subepithelial layer before the therapy showed good response to macrolides, and a number of IgA positive cells decreased after the therapy. 3) The number of IgE and IgM positive cells showed little change after the therapy. IgG positive cells tended to increase in number after the therapy. 4) The ratio of number of IgA positive cells and IgE positive cells (IgA/E) significantly decreased after the therapy, especially in responders to the therapy. 5) The value of IgA/E was significantly low in eosinophil-dominant cases. These results suggested that macrolides suppress chronic inflammatory response except for eosinophil and IgE-dominant inflammation.
The patients of diseases caused by nontuberculous mycobacteria (NTM) newly diagnosed in 1993 in Hiroshima Prefecture were investigated retrospectively. During 1993, 59 newly diagnosed patients of NTM disease, who were the resident of Hiroshima Prefecture were reported from 6 hospitals. Mycobacterium avium complex (MAC) disease was most frequent (53 patients, 90%) and M. kansaii (MK) disease, which accounts for more than 20 percent of all the NTM diseases in the national survey of Japan, was found only in 3%. Other pathogenesis were M. chelonae and M. fortuitum. Incidence rate for all NTM disease per 10(5) population was 2.1. Age-specific incidence rate calculated from the estimated population of Hiroshima Prefecture was; less than 0.4/10(5) under the age 40, 4.0/10(5) in the age group 50 to 59, 4.5/10(5) in the age group 60 to 69 and 9.4/10(5) in the age group over 70. Thirty-one patients (57%) had underlying pulmonary disease such as previous lung tuberculosis (TB) and previous history of TB was found in 41 percent of patients over 60 yr. of age. The data suggest that epidemiological picture of NTM diseases may change in the future. Relative increase of elder population will lead to the increase of NTM diseases as a whole; the incidence rate calculated from the age specific incidence rate and predicted population of Japan in 2025 is 3.1/10(5), which is 1.5 fold higher than the present rate. However, secondary NTM diseases with healed TB will decrease because of the sharp decline of TB morbidity in Japan. Assuming that secondary NTM disease with healed TB decreases to one-fourth, estimated incidence rate will be 2.3. Further, the upward tend of MK disease in Japan should be taken into consideration. Thus, the future trends of NTM diseases will increase fairly due to the increase of elder population as well as the MK disease. It was pointed out that many NTM disease cases had been counted as tuberculosis in the surveillance system of Japan. In our present study, 52 (82%) were registered as tuberculosis in the beginning and only 19 cases were reported later to health centers as NTM disease. As tuberculosis classification and surveillance system in Japan were changed from 1996 to separate NTM disease from TB, NTM disease cases will be counted separately in the tuberculosis statistics. This revision in the management of NTM disease should be taken into account when discussing the trend of tuberculosis statistics in Japan.
The purpose of the study was to determine the concentration of heparin to be added to iopamidol in order to assure adequate anticoagulant activity and tolerability. Iopamidol that contained heparin at a concentration of 3 U/ml showed the anticoagulant activity similar to ionic contrast agents, while maintaining excellent tolerability.
Hydroperoxide formation during Maillard reaction (amino-carbonyl reaction) was investigated using luminol-chemiluminescence-high performance liquid chromatography (CL-HPLC). From the equimolar reaction mixture of 1 M beta-alanine/D-glucose in phosphate buffer (pH 8.0) at 95 degrees C, two hydroperoxides and H2O2 were detected as chemiluminescent products in CL-HPLC, and the yields were proportional to the browning development. One of these hydroperoxides was isolated and identified as 3-hydroxy-5-hydroperoxy-2-methyl-5,6-dihydropyran-4-one (HMDP, pyrone hydroperoxide) by fast atom bombardment mass spectrometry. The HMDP formation was also confirmed in L-lysine/D-glucose and in bovine serum albumin/D-glucose with the physiological incubation at 37 degrees C for 4 days and 3 wk, respectively. Incubation at 37 degrees C of human plasma containing 5.5-25.0 mM of D-glucose for 60 h showed the glucose concentration-dependent formation of HMDP (10-35 microM of H2O2 equivalence). The HMDP was negative to thiobarbituric acid reaction and was degraded by peroxidases such as horseradish peroxidase, Athromyces ramosus peroxidase, heated cytochrome c, and microperoxidase. The results strongly suggested the formation of such hydroperoxide even in biological Maillard reaction termed as glycation, and implied its contribution in pathogenesis and oxidative lesions associated with hyperglycemia.
We investigated effects of site-specific mutation of the putative C/EBP binding site in the feline immunodeficiency virus (FIV) long terminal repeat (LTR) on the basal promoter activity in Crandell feline kidney (CRFK) cells and on replication efficiency in CRFK cells and a T-lymphoblastoid cell line, MYA-1 cells. Mutation of the C/EBP site reduced the basal promoter activity in CRFK cells and prevented efficient FIV replication in both CRFK and MYA-1 cells. Gel-mobility-shift assay using nuclear extracts from CRFK and MYA-1 cells revealed that the nuclear factor(s) actually binds to the C/EBP site, but there was a clear difference in the binding patterns to the C/EBP site between CRFK and MYA-1 cell nuclear proteins. Furthermore, we demonstrated that the C/EBP site is necessary for inhibition of FIV LTR-directed gene expression by pseudorabies virus (PRV) ICP4. The C/EBP site is sufficient to confer inhibitory effect by PRV ICP4 on heterologous promoters. These data suggest that the C/EBP site in the FIV LTR is important for the positive regulation of FIV gene expression and replication and is also required for the negative regulation of FIV gene expression by PRV ICP4.
The crystal structure of a class I aminoacyl-transfer RNA synthetase, glutamyl-tRNA synthetase (GluRS) from Thermus thermophilus, was solved and refined at 2.5 A resolution. The amino-terminal half of GluRS shows a geometrical similarity with that of Escherichia coli glutaminyl-tRNA synthetase (GlnRS) of the same subclass in class I, comprising the class I-specific Rossmann fold domain and the intervening subclass-specific alpha/beta domain. These domains were found to have two GluRS-specific, secondary-structure insertions, which then participated in the specific recognition of the D and acceptor stems of tRNA(Glu) as indicated by mutagenesis analyses based on the docking properties of GluRS and tRNA. In striking contrast to the beta-barrel structure of the GlnRS carboxyl-terminal half, the GluRS carboxyl-terminal half displayed an all-alpha-helix architecture, an alpha-helix cage, and mutagenesis analyses indicated that it had a role in the anticodon recognition.