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Biomedical subjects

H Amano

Publications and source records attributed to H Amano.

At least 181 records · Page 10Linked to original sources
PubMed1991

Isolation of Corynebacterium kutscheri from aged Syrian hamsters (Mesocricetus auratus).

Corynebacterium kutscheri was isolated from the oral cavities of 12 male Syrian hamsters (Mesocricetus auratus) which were about 12 months old. At 1, 5, and 9 months after initial isolation of C. kutscheri from the oral cavity, hamsters were euthanatized, and attempts were made to culture C. kutscheri from 13 additional sites. Corynebacterium kutscheri was isolated from nine hamsters, and regardless of the hamsters' ages, the organisms were most frequently isolated from the oral cavity (100%), esophagus (100%), cecal content (100%), and colon and rectum (88.9%). Isolation rates in the nasal cavity were 66.7%, followed by 55.5% in the trachea and 33.3% in the submaxillary lymph nodes. The number of the organisms found in the submaxillary lymph nodes and esophagus was 10(3) to 10(4) CFU/g. The number found in the cecal content and in the colon and rectum was 10(2) to 10(5) CFU/g. The organisms were not isolated from lung, stomach, kidney, spleen, and mesenteric lymph node tissues. The hamsters had neither clinical signs nor lesions. However, 7 of 12 animals had low agglutinating antibody titers. The Syrian hamster can therefore be an asymptomatic carrier of C. kutscheri.

Aging↗
PubMed1990

Measurements of the isometric contractile forces generated by dog periodontal ligament fibroblasts in vitro.

One hypothesis for the mechanism of tooth eruption is that the periodontal ligament fibroblasts generate the eruptive force. To assess the force generated, these fibroblasts were obtained by explant culture of ligament from mandibular premolars of a dog and were cultured in collagen gel matrices. The forces generated by them under isometric conditions were continuously measured for 120 h with a strain gauge. At the same time the number of cells in the gel was counted and the force measured was calculated as the force generated by 10(4) cells. Shortly after the start of culture, the force per 10(4) cells increased rapidly; it reached 5.2 X 10(-4) N at 8 h, and then remained at the same level for about 48 h. Our findings suggest that fibroblasts of the periodontal ligament may generate sufficient force for tooth eruption.

Animals↗
PubMed1990

Angiotropic lymphoma with histologic features of neoplastic angioendotheliomatosis presenting with predominant respiratory and hematologic manifestations. Report of a case and review of the literature [corrected].

Neoplastic angioendotheliomatosis (NAE) is a rare fatal disease characterized by widespread intravascular proliferations of neoplastic mononuclear cells. Clinically, dermatologic and bizarre neurologic manifestations usually predominate. The origin of the neoplastic cells remains still undetermined. The authors report a patient with NAE peculiar with respect to the following points: (1) the patient predominantly manifested respiratory symptoms and hematologic findings and lacked cutaneous or neurologic manifestations; and (2) immunohistochemical and molecular genetic studies showed the B-cell nature of the neoplastic cells, although previous cases with predominant respiratory or hematologic manifestations were reported to be of endothelial origin. Despite the rarity, this type of NAE or angiotropic [corrected] lymphoma should be recognized because it is easily confused with other disorders, particularly vasculitis or thrombotic thrombocytopenic purpura.

Aged↗
PubMed1990

Epidermal growth factor prolongs survival time of tumor-bearing mice.

We observed that human epidermal growth factor (hEGF) alone prolonged the survival time of mice bearing various murine syngeneic tumors as well as athymic nude mice bearing human xenografts. No changes in the subcutaneous solid tumor mass volume were observed. Prolongation of survival time by hEGF was observed in mice bearing murine epidermoid carcinoma (BSC) and human gastric carcinoma (KATO III), but not in murine epidermoid carcinoma (KLN205) or human epidermoid carcinoma (A431). Human tumor cells such as A431, KATO III, and murine tumor cells, KLN205, BSC had roughly 2 X 10(6), 3 X 10(4), 1.3 X 10(3) and 1 X 10(3) EGF receptors/cell, respectively. Although KLN205 and BSC tumor cells maintained nearly the same number of EGF receptors, the effects of hEGF were very different. Although A431 tumor cells had nearly 100 times more receptors than KATO III cells, the prolongation of survival time of mice bearing A431 by hEGF was no better than that of mice bearing KATO III. Accordingly, it appears that this prolongation of survival time by hEGF is independent of the number of EGF receptors on tumor cells. In addition, hEGF was shown to inhibit experimental pulmonary metastasis of murine BSC tumor, but was ineffective with murine KLN205 tumor. These results suggest that prolongation of survival time by hEGF may result from the inhibition of tumor cell metastasis and EGF may play a role in preventing the metastasis of certain malignant neoplasms unrelated to its effects through the EGF receptor on tumor cells.

Adenocarcinoma↗
PubMed1990

Antipurified-protein-derivative antibody in tuberculous pleural effusions.

Using ELISA, we studied anti-PPD antibody values in 31 tuberculous and 39 carcinomatous pleural effusions. Mean ODI values of anti-PPD IgG, IgA and IgM antibodies in tuberculous pleural effusions were higher than those in carcinomatous pleural effusions (p less than 0.01 in IgG and IgA, p less than 0.05 in IgM antibodies). We also analyzed the detected antigens in PPD and BCG whole cell fraction recognized by IgG antibody in tuberculous pleural effusions. Among heteromolecular components, the antigen band from 25 to 40 Kd region was most frequently stained. This antigen was heat-stable, contained sugar components, and included no disulfide bonds.

Adolescent↗
PubMed1990

Teratogenic evaluation of tributyltin chloride in rats following oral exposure.

The teratogenicity of tri-n-butyltin chloride (TBTC1) was examined in Wistar rats. The pregnant rats were administered orally 25, 15, 9, 5 and 0(Control) mg of TBTC1/kg of body weight/day from day 7 to 15 of pregnancy. Maternal toxicity, as evidenced by both of decreased body weight gain and food consumption was observed at 25, 15 and 9 mg/kg/day dose group. However, only in the 25 mg/kg/day dose group some clinical signs of toxicity (sedation, diarrhoea and salivation) were observed and 70 percent of the dams were dead. In the 25 mg/kg/day dose group, all fetuses were dead. Statistically significant reductions in the female fetal body weight were observed in 9 and 5 mg/kg/day dose groups. In all groups treated with TBTC1 except the 25 mg/kg/day dose group, no significant differences in the numbers of live fetuses and intrauterine death (dead fetuses and resorptions) or sex ratios of fetuses were found between the TBTC1-treated and control groups. Fetal external, skeletal and internal malformations were not observed at any of the dose levels. However, several types of skeletal and internal variations including delayed ossifications were observed in some groups treated with TBTC1, but the incidences were not significantly different from controls. Also, two fetuses with dilatation of the renal pelvis were found in 9 and 5 mg/kg/day dose group. Statistically significant increases of placental weight in all TBTC1-treated groups were observed when compared to that of control group. In conclusion, TBTC1 administered orally to Wistar rats during days 7-15 of pregnancy produced related signs of fetal toxicity but no evidence of teratogenicity and induced a marked increase in placental weight.

Abnormalities, Drug-Induced↗
PubMed1990

[National Institute of Hygienic Sciences Standard (the Japanese Pharmacopoeia Standard) "Endotoxin Reference Standard" (Control 891)].

The second "Endotoxin Reference Standard" (Control 891) of the National Hygienic Sciences (Japanese Pharmacopoeia Standard) was prepared. As a result of the test of its potency against the preceding lot of the Reference Standard (Control 881), the second "Endotoxin Reference Standard" (Control 891) containing 16000 endotoxin units per vial was authorized.

Endotoxins↗
PubMed1990

[An investigation into the actual condition of the sports drink intake on children].

The purpose of this study was to investigate the actual condition of the sport drink intake on children. We conducted an investigation by means of questionnaires at 3 nursery schools and a day nursery in and around Hiroshima City, and using 505 answers with the comparison between 4 areas. The following results were obtained: 1) Less than 10% of the children often took sport drinks and about 70% of the children sometimes. 2) In response to the question of when taken, 40-50% of answers revealed that the drinks were taken when the children ill and 20-40% of answers were take from home. 3) In response to the question as to why children begin to take the drinks, many parents answered that they were advised by a doctor and a nurse to give their child sport drinks to prevent for dehydration, when their children were ill. This answer accounted for about 60% of the answers to this question. 4) Parents imagined that fruit drinks, carbonated beverages and beverages with lactic acid promoted tooth decay. Also the image of cariogenicity was less than 100% fruit juices, home-made juices, sport drinks, cow milks and water or tea in that order. The results suggest that parents regard sport drinks as beverages which do not promote tooth decay and give their child sport drinks frequency.

Beverages↗
PubMed1990

[Difference in the path between the incisal point and the tracer of simple mandibular movement recording apparatuses during the mandibular movement in the sagittal plane].

In order to study the difference in the path between the incisal point and its tracers, which were LED or a magnet, for two types of mechanism used in ready-made simple mandibular movement recording apparatuses, we calculated their locations during the rotally opening or protrusion of the mandible in the sagittal plane. The movement of the LED tracer was larger than that of the incisal point during the rotally opening movement, and its magnification ratio increased with increased opening. During the protrusion, the difference in their movements was affected by the balance of the inclination of the condyle path and the incisal path, and the movement of the tracer expanded vertically but contracted horizontally as the inclination of the incisal path was increased. The movement of magnet tracer was larger than that of the incisal point during the opening movement, but its magnification ratio decreased as the degree of opening increased. During the protrusion, the horizontal movement of the tracer was smaller than that of the incisal point, and its magnification ratio decreased as the inclination of incisal path became smaller. Its vertical movement was similar to that of the incisal point.

Dental Occlusion↗
PubMed1990

[Evaluation of imipenem/cilastatin sodium in the treatment of respiratory tract infections].

Imipenem/cilastatin sodium (IPM/CS) was administered to 55 patients with respiratory tract infections (RTI). A clinical evaluation of IPM/CS was carried out in 51 patients, 28 with pneumonia, 4 with pulmonary abscess, 1 with pyothorax, 6 with bronchitis, 9 with bronchiectasis, 1 with diffuse panbronchiolitis and 2 with RTI with chronic obstructive pulmonary disease, and the clinical efficacy rate was 78.4%. Causative organisms were isolated in 23 strains out of 20 patients, such as Staphylococcus aureus 4 strains, Staphylococcus epidermidis 1 strain, Streptococcus pneumoniae 1 strain, Branhamella catarrhalis 1 strain, Haemophilus influenzae 2 strains, Klebsiella pneumoniae 4 strains, Pseudomonas aeruginosa 6 strains, Pseudomonas sp. 1 strain, Acinetobacter calcoaceticus 1 strain, Acinetobacter sp. 1 strain and glucose non-fermentative Gram-negative rod 1 strain. An eradication rate of 70.6% was obtained. An overall eradication rate of main causative organisms in RTI including S. aureus, S. pneumoniae, H. influenzae and K. pneumoniae was 75.0%. Clinical adverse effects were observed in 5 patients, and these were eruption in 2, itching in 1, vomiting in 1 and drug fever in 1. Abnormalities in laboratory test results were observed in 8 patients. These disappeared or returned to normal values after completion or discontinuation of IPM/CS administration. IPM/CS appears to be a useful antibiotic for the treatment of RTI, especially severe infections.

Adult↗
PubMed1990

[Three cases of malignant lymphoma developing from chronic empyema wall].

Three patients with non-Hodgkin's lymphoma (NHL) involving the lung or chest wall are reported. All patients had tuberculous pleuritis or received artificial pneumothorax for pulmonary tuberculosis 30 years or more previously. The NHL of these patients developed in or close to the thickened pleura. Histologic examination showed diffuse large cell type (LSG classification) in all cases. Lymphomas of all cases were considered to have originated from B-cell lineage because their neoplastic cells expressed B1 (CD20) antigens. In no case the tumors were resectable, and chemotherapy or radiotherapy were performed. Two died of local NHL at 5 and 6 months respectively after diagnosis. One patient is still alive at 8 months after the first treatment for NHL. Early diagnosis is essential to improve the prognosis of these NHLs although it is difficult because of the co-existent pyothorax. Following features seemed to be useful for diagnosis: 1) chest pain or shoulder pain, 2) elevation of LDH level, 3) mass shadow in computed tomography, and 4) abnormal uptake of gallium 67. As precise assessment of tumor size is difficult because of the co-existent pyothorax and necrosis, follow-up studies by gallium scan or magnetic resonance imaging might be useful for proper treatment.

Chronic Disease↗
PubMed1989

Acute transformation of chronic large granular lymphocyte leukemia associated with additional chromosome abnormality.

A patient with large granular lymphocyte (LGL) leukemia that transformed into an acute or aggressive form after 20 months of the chronic phase is reported. The patient's leukemic cells were mature, medium-sized lymphocytes with sparse azurophil granules and the surface phenotypes of the cells were CD2+, CD3-, CD11+, and CD16+. Molecular analysis showed a germ line configuration in both T-cell receptor beta-chain genes and T-cell receptor tau-chain genes. A clonal anomaly of chromosome (trisomy 8) was demonstrated in peripheral blood cells. LGL after acute transformation of the disease displayed large blastic morphology with prominent nucleoli, intense basophilic cytoplasm, and numerous granules. Karyotypic analysis demonstrated a mosaic of trisomy 8 and trisomy 8 with an additional marker chromosome. Thus, transformation of chronic LGL leukemia into an acute or aggressive form in this patient was associated with morphologic and karyotypic changes of the leukemic cells. Patients with a stable form of chronic LGL leukemia should be examined carefully for the possible acute crisis associated with a clonal evolution.

Adult↗
PubMed1989

Comparative study on metabolic formation of N-arylformamides and N-arylacetamides from carcinogenic arylamines in mammalian species.

The metabolism of carcinogenic arylamines was examined focusing on their N-acylation in mammalian species. When 4-aminobiphenyl, 2-aminonaphthalene, 2-aminofluorene, or 1-aminopyrene was given orally to rabbits, the corresponding N-arylformamides were isolated from the urine together with the corresponding N-arylacetamides. Identification of these N-arylformamides and N-arylacetamides was performed unequivocally by comparing their mass and UV spectra, and thin-layer chromatographic behaviors with those of authentic samples. Such metabolic conversion of the arylamines to the N-arylformamides and N-arylacetamides was also observed in guinea pigs and rats. In addition, carcinogenic nitro compounds such as 4-nitrobiphenyl and 2-nitronaphthalene, which are metabolically reducible to the arylamines, were metabolized to the corresponding N-arylformamides and N-arylacetamides in rabbits. On the other hand, quantitative experiments showed that only minor amounts of the N-arylformamides and N-arylacetamides were excreted in the urine or feces of rats and rabbits given the arylamines. This seems to be due to almost complete further metabolism of these N-acyl derivatives in vivo. Liver cytosols from several mammalian species exhibited a significant N-formylating activity toward the arylamines in the presence of N-formyl-L-kynurenine and N-acetylating activity in the presence of acetyl-CoA. In rabbits, the N-formylating activity was clearly higher than the N-acetylating activity, while the reverse was the case in guinea pigs and hamsters. The experiments with rat liver preparations showed that the liver cytosolic N-formylating and N-acetylating activities are due to formamidase and arylamine acetyltransferase, respectively. Furthermore, enzymatic transfer of the formyl group from one arylamine to another was demonstrated.

2-Naphthylamine↗
PubMed1989

Endoscopic pancreatic sphincterotomy--technique and evaluation.

Endoscopic pancreatic sphincterotomy has been developed as a new method of treatment of chronic pancreatitis in our institution since 1982. We introduced pancreatic sphincterotomy as a safe technique, after performing it successfully in 21 cases of chronic pancreatitis without any complications, and relieving both abdominal and back pain in 19 of the cases. Recently, we have added endoscopic elimination of viscid pancreatic juice including protein plugs. This report describes our procedure of pancreatic sphincterotomy in detail, and evaluates it in the endoscopic treatment of chronic pancreatitis.

Adult↗