Biomedical subjects

T Kodama

Publications and source records attributed to T Kodama.

At least 649 records · Page 36Linked to original sources

PubMed1990

Coiled-coil fibrous domains mediate ligand binding by macrophage scavenger receptor type II.

The macrophage scavenger receptor, which has been implicated in the pathogenesis of atherosclerosis, has an unusually broad binding specificity. Ligands include modified low-density lipoprotein and some polyanions (for example, poly(I) but not poly(C]. The scavenger receptor type I (ref. 3) has three principal extracellular domains that could participate in ligand binding: two fibrous coiled-coil domains (alpha-helical coiled-coil domain IV and collagen-like domain V), and the 110-amino-acid cysteine-rich C-terminal domain VI. We have cloned complementary DNAs encoding a second scavenger receptor which we have termed type II. This receptor is identical to the type I receptor, except that the cysteine-rich domain is replaced by a six-residue C terminus. Despite this truncation, the type II receptor mediates endocytosis of chemically modified low-density lipoprotein with high affinity and specificity, similar to that of the type I receptor. Therefore one or both of the extracellular fibrous domains are responsible for the unusual ligand-binding specificity of the receptor.

Amino Acid Sequence↗

PubMed1990

[Pulmonary complication following intra-arterial infusion of lipiodol-adriamycin emulsion for hepatocellular carcinoma, report of a case].

A case of acute pulmonary complication following intra-arterial infusion of Lipiodol-Adriamycin emulsion for hepatocellular carcinoma was reported. Intra-arterial infusion chemotherapy was performed on a 75-year-old male with Lipiodol-Adriamycin emulsion (Lipiodol 8 ml + Adriamycin 40 mg). Severe dyspnea and cyanosis started about 30 minutes after the infusion, and blood gas analysis revealed hypoxemia and hypocapnia. Chest X-ray revealed diffuse infiltrative shadow throughout the both lungs. He was on positive end-expiratory pressure breathing for 4 days. Clinical symptoms and chest X-ray improved rapidly in the course of two weeks, he became almost asymptomatic. We concluded that the nature of this pulmonary damage was pulmonary edema due to the large amount of Adriamycin that flowed into pulmonary artery via arterio-venous shunt present in the hepatocellular carcinoma.

Aged↗

PubMed1990

Augmented enkephalin-immunoreactivity in adrenaline-producing phaeochromocytomas.

Immunohistochemical studies for methionine- and leucine-enkephalin were performed on 26 phaeochromocytomas to elucidate the patho-physiological roles of enkephalins. Positive reactions were seen in all phaeochromocytomas with varying intensities. The location of methionine- and leucine-enkephalin agreed fairly well with each other. Stronger immunostaining was obtained in phaeochromocytomas secreting both adrenalin and noradrenaline than in those secreting predominantly noradrenaline. Paroxysmal hypertension was frequently observed in patients with adrenalin-secreting phaeochromocytomas, especially those with marked enkephalin positivity. Urinary excretion of metanephrine was significantly correlated with enkephalin positivity. These findings show that all phaeochromocytomas retain the ability to produce enkephalins of the adreno-medullary or extra-medullary chromaffin tissues from which they derive. Augmented enkephalin-immunoreactivity in adrenalin-producing phaeochromocytomas may be interpreted as reflecting a close association of enkephalins with adrenalin under physiological conditions.

Adrenal Gland Neoplasms↗

PubMed1990

Mid-mediastinal parathyroid lesions: preoperative localization and surgical approach in two cases.

Although hyperfunctioning mediastinal parathyroid lesions that require median sternotomy or thoracotomy for removal are occasionally present, the majority are located in the anterior mediastinum closely associated with the thymus. Only eight cases of ectopic hyperfunctioning parathyroid tumors in the middle mediastinum have been reported. We experienced two cases of either persistent or recurrent hyperparathyroidism in which abnormal parathyroid tissue was located in the aorticopulmonary window. One of the patients had a parathyroid adenoma and the other had metastatic lesions of parathyroid carcinoma. In both cases, thallium scanning proved useful in identifying the lesions while computed tomography scan was effective for mediastinal three-dimensional localization. In one case, single photon emission computed tomography imaging with thallium proved beneficial for both identification and localization of the middle mediastinal lesion. The surgical approach used in both cases was different. In one case, left thoracotomy was performed, after which the ligamentum arteriosum was divided, and an adenoma anterior to the left main bronchus and posterior to the left pulmonary artery removed. In the other case, two metastatic tumors of parathyroid carcinoma anterior to the right main bronchus and posterior to the right pulmonary artery were resected through a median sternotomy and opening of the pericardium.

Adenoma↗

PubMed1990

Primary adrenocortical micronodular dysplasia: enzyme histochemical and ultrastructural studies of two cases with a review of the literature.

The adrenal glands from two patients with primary adrenocortical micronodular dysplasia (PAMD) were studied (no. 1, a 23-year-old man with cardiac myxomas and sarcoidosis; no. 2, a 16-year-old girl). The PAMD cells showed intense activity of 3 beta-hydroxysteroid dehydrogenase (3 beta DH), succinate DH, glucose-6-phosphate DH, alkaline phosphatase (AlPase), and other DHs and lysosomal hydrolases, giving a characteristic staining pattern. The staining patterns correlated well with ultrastructural findings. The larger adrenals (no. 1: 16.6 g) were associated with larger black nodules and internodular cortex (INC) with fairly well-retained enzyme activities, and contained cell clusters and single cells with intense AlPase activity with the appearance of PAMD nodules in the buds. The smaller adrenals (no. 2: 5.4 g) were associated with smaller black/yellow nodules, and had INC with weaker enzyme activity. Analysis of descriptions of INC in 25 previously reported cases revealed that the larger adrenals (more than 10 g) had less atrophic INC than the smaller ones. The characteristic enzyme pattern in PAMD cells explains the paradox that PAMD adrenals smaller than normal can cause Cushing's syndrome, and may be useful for investigating neoplastic and non-neoplastic counterparts in other adrenal lesions. The relationship between PAMD cells and INC is not simply one of autonomy versus atrophy, and both cell types may be stimulated by a certain common trophic factor. Thus, PAMD belongs to the category of hyperplasia.

3-Hydroxysteroid Dehydrogenases↗

PubMed1990

An investigation of an infrared ray electronic endoscope with a laser diode light source.

An infrared ray electronic video-endoscope with a laser diode light source was used to obtain information on the submucosal area. As contrast medium we employed indocyanine green, which has a light absorption peak in the infrared range. The wavelength of the laser diode was set to 810 nm as suggested by the results of the spectrophotometric study on the reflected light at fingertips after injection of ICG (3 mg/kg). Using this system we inspected the stomach under visible light and then continuously under infrared light before and after intravenous injection of ICG (2 mg/kg). A dendritic figure with fine ramifications emerged in the early stage after intravenous injection of indocyanine green, which was not seen under visible light. These features of the figure visualized by the infrared endoscope suggest that they have a close relationship with blood vessels and blood circulation beneath the mucosal surface. This infrared electronic endoscope system provides submucosal information more readily and at a lower cost than ever before, and also the infrared lighting method of this system could be applied to almost all available electronic endoscopes by modulating infrared cutting filters, so it could become a valuable clinical tool.

Electronics, Medical↗

PubMed1990

Multiple antigenic epitopes expressed on gag proteins, p26 and p15, of a human immunodeficiency virus (HIV) type 2 as defined with a library of monoclonal antibodies.

Thirty-two hybridoma clones producing monoclonal antibody (MAb) against HIV-2[GH-1] were established from mice immunized with NP-40-disrupted purified whole virus of a Ghanaian isolate of human immunodeficiency virus type 2 (HIV-2), strain HIV-2[GH-1]. Of these 32 MAbs, 20 reacted with p26 and the other MAbs recognized p15 of the HIV-2[GH-1] isolate. From the results of serological characterization by these MAbs, p26 and p15 were identified as capsid proteins and matrix protein, respectively, of HIV-2[GH-1] gag products. In addition to two gag proteins, a 55-kD protein corresponding to the primary translational product of gag gene and 39-kD protein corresponding to an intermediate product of cleavage of p55 were recognized by these MAbs in the lysate of HIV-2[GH-1]-infected cells. Moreover, these MAbs were used to analyze the number of antigenic epitopes on p26 and p15 of HIV-2[GH-1] isolate. The results of cross-reactivity with different HIV-1, HIV-2, and simian immunodeficiency virus (SIV) isolates and competitive binding assay suggest that there are at least four and five antigenic epitopes in p26 and p15, respectively, of the HIV-2[GH-1] isolate. The biological activity of MAbs was studied by performing syncytium inhibition assay and infection inhibition assays. However, our MAbs could not inhibit syncytium formation and infection by cell-free virus.

Animals↗

PubMed1990

Lack of association between blood pressure and insulin in patients with insulinoma.

To investigate the hypothesis that insulin affects the regulation of blood pressure, blood pressure and fasting insulin and glucose levels were measured in seven patients with insulinoma both before and after resection of the insulinoma. The diagnosis of all insulinoma cases was confirmed during surgery. Before surgery, systolic and diastolic blood pressures were 127 +/- 15 and 74 +/- 9 mmHg, respectively, and did not correlate with the fasting insulin levels. At least 3 weeks after the surgery, significant decreases in fasting insulin levels (from 568 +/- 571 to 74 +/- 43 pmol/l, P less than 0.005) and body weight (-9.8 +/- 7.1%, P less than 0.05) were observed along with a significant increase in fasting glucose levels (98.2 +/- 43.2%, P less than 0.001). However, both systolic (-4.7 +/- 9.9%) and diastolic (-0.2 +/- 6.3%) blood pressures remained unchanged. The changes in fasting insulin levels were not linearly correlated with those in systolic and diastolic blood pressures. Even after the changes in both body weight and fasting glucose levels were taken into consideration using partial correlations, the changes in fasting insulin levels did not correlate with those in systolic and diastolic blood pressures. It was concluded that blood pressure, both systolic and diastolic, was not at hypertensive levels in the patients with insulinoma and showed no decrease after resection of the insulinoma. Therefore, insulin may not affect the regulation of blood pressure in patients with insulinoma.

Adenoma, Islet Cell↗

PubMed1990

Characterization of monoclonal antibodies that distinguish simian immunodeficiency virus isolates from each other and from human immunodeficiency virus types 1 and 2.

Two monoclonal antibodies (MAbs) against p27 and one against p17 of simian immunodeficiency virus (SIV) from rhesus macaques were produced and characterized by reacting with disrupted, viral antigens on immunoblots. Human immunodeficiency virus type 1 (HIV-1), HIV-2 and SIV isolates from sooty mangabey, stump-tailed macaque, rhesus macaque and African green monkey (SIVSM, SIVStM, SIVMAC and SIVAGM) were used for comparative analysis. The p27 monoclonal antibodies HE3 and FA2 reacted with SIVMAC and SIVSM, but not with HIV-1, HIV-2, SIVStM and SIVAGM. The p17 monoclonal antibodies reacted with SIVMAC and SIVStM, but not HIV-1, HIV-2, SIVSM and SIVAGM. The differential reactivity of these monoclonal antibodies indicated that common conserved antigenic epitopes are shared between SIVMAC and SIVSM with respect to p27 MAbs and between SIVMAC and SIVStM with respect to p17. Since these MAbs reacted differently with the SIV isolates, they are useful reagents for comparative pathogenesis studies for differentiating SIV isolates.

Animals↗

PubMed1990

Human platelets effectively kill K-562 cells, a chronic myelogenic leukemia cell line, in vitro.

The cytotoxic effect of isolated human platelets on leukemic cells has been examined in order to investigate the role of platelets in host defense systems. K-562 cells (a chronic myelogenic leukemia cell line) showed significant change in their morphology and were killed when they were incubated with platelets in serum-free medium for several hours at 37 degrees C, a condition where no killing of normal peripheral lymphocytes occurred. Some protease inhibitors inhibited the cytotoxicity of platelets against K-562 cells. Our results suggest that platelets may be involved in host defense against neoplasia and that certain proteases are implicated in the cytotoxic effect of platelets.

Blood Platelets↗

PubMed1990

Interleukin-2 receptor antigen, leukocyte common antigen, and Ki-1 antigen-expressing gastric plasmacytoma. A case report with an immunohistochemical study.

A case of primary gastric plasmacytoma expressing various surface and cytoplasmic antigens is reported. With the use of formalin-fixed and deparaffinized sections, 13 different antibodies were applied. Neoplastic plasma cells revealed monoclonal IgG and kappa light chain in the cytoplasm, and expressed epithelial membrane antigen, Ki 67 antigen, cytokeratin, CD 22 antigen, interleukin-2 receptor antigen, leukocyte common antigen and Ki-1 (CD 30) antigen. However, tumor cells were devoid of HLA-DR antigen. These data suggest that the neoplastic plasma cells are at the plasmoblastic stage of maturation and express various surface and cytoplasmic phenotypes.

Aged↗

PubMed1990

[Studies on respiratory infections in primary care clinic (III). Distribution of bacteria isolated from patients with respiratory infections visiting 21 private clinics in the Tohoku District of Japan].

The bacteriology of the isolates from the throat swab and the sputum respectively of 2,539 patients with respiratory infections visiting 21 private clinics in Tohoku district of Japan during the period from January to April in 1989 was documented. Of the 2,539 patients, 1,694 had an acute upper respiratory infection, 609 had acute bronchitis, 46 had acute pneumonia, 84 had acute exacerbation of chronic respiratory infections and 106 had respiratory infections without diagnosis registered. 1887 (74.3%) strains of potential pathogens were recovered from 1507 (59.4%) of the 2539 cases. The rate of recovery of potential pathogens was very high in patients of the younger age. These patients had elevated body-temperature. There were statistically significant differences in recovery rate when classified by diagnosis, prefecture and the period of investigation. Of the 1,887 strains, 996 (52.8%) were gram-positive and 891 (47.2%) were gram-negative bacteria. The rate of recovery of gram-negative bacteria was high in patients who were less than 10 years old and more than 51 years old, in patients with pneumonia and chronic respiratory infections, and in patients with fever. Of the 1,887 strains, those which exceeded 100 were Staphylococcus aureus (481 strains), Haemophilus influenzae (340 strains), Streptococcus pneumoniae (329 strains), Streptococcus pyogenes (117 strains) and Acinetobacter spp. (100 strains). Species other than those mentioned above had less than 100 strains. In this group there were 39 strains of Branhamella catarrhalis, 32 strains of Escherichia coli, 97 strains of Klebsiella spp., 40 strains of Enterobacter spp., 25 strains of Serratia spp., 12 strains of Pseudomonas aeruginosa and 43 strains of Pseudomonas putida. There was a remarkable difference in recovery rate of each species when classified by diagnosis, age class, prefecture and the period of investigation, respectively. The above results indicated that gram-positive bacteria are more frequent than gram-negative bacteria, that enterobacteriaceae and glucose-non-fermentative gram-negative bacteria are only rarely found in primary care clinics, and that the bacteriology in primary care clinic is different from that of medical school-affiliated hospitals.

Adolescent↗

PubMed1990

[Studies on respiratory infections in primary care clinic (IV). Antibiotic sensitivity of bacteria isolated from patients with respiratory infections visiting 21 private clinics in the Tohoku District of Japan].

We determined the MICs of ampicillin, methicillin, cefaclor, cefixime, cefteram, ofloxacin and ciprofloxacin against a total of 1,448 strains from 11 species: 464 strains of Staphylococcus aureus, 306 strains of Streptococcus pneumoniae, 114 strains of Streptococcus pyogenes, 37 strains of Branhamella catarrhalis, 329 strains of Haemophilus influenzae, 32 strains of Escherichia coli, 66 strains of Klebsiella pneumoniae, 26 strains of Enterobacter cloacae, 20 strains of Serratia marcescens, 12 strains of Pseudomonas aeruginosa and 42 strains of Acinetobacter calcoaceticus, isolated from the throat swab and the sputum of 2,539 patients with respiratory infections who visited 21 private clinics in Tohoku district of Japan during the period from January to April in 1989. Ciprofloxacin and ofloxacin were more active against S. aureus, B. catarrhalis, P. aeruginosa and A. calcoaceticus than other antibiotics. Ampicillin and cefteram were more active against S. pneumoniae and S. pyogenes than other antibiotics. New-quinolones and cephems of new-generation were active against H. influenzae, E. coli, K. pneumoniae, E. cloacae and S. marcescens. Of 30 strains of S. aureus which were resistant (MIC greater than or equal to 12.5 micrograms/ml) to ampicillin, only one strain was resistant (MIC greater than or equal to 12.5 micrograms/ml) to methicillin. Twenty strains (6.5%) of S. pneumoniae and 49 strains (14.9%) of H. influenzae were resistant (MIC greater than or equal to 1.56 micrograms/ml) to ampicillin. Of 101 strains of H. influenzae of which their beta-lactamase activity was determined by Nitrocephin-method, 27 (26.7%) were beta-lactamase-positive strains. The above results indicated that MRSA is only rarely found in primary care clinics but the incidence of ampicillin-resistant H. influenzae in primary care clinics is almost the same as that of the intensive care clinic, i.e. medical school-affiliated hospitals. Therefore caution should be exercised as regards antibiotic resistance of the causative organism even in primary care clinics.

Ambulatory Care Facilities↗

PubMed1990

Efficient removal of albumin-bound furancarboxylic acid, an inhibitor of erythropoiesis, by continuous ambulatory peritoneal dialysis.

3-Carboxy-4-methyl-5-propyl-2-furanpropionic acid, which cannot be removed by conventional hemodialysis due to its strong albumin binding, was found to be efficiently removed by continuous ambulatory peritoneal dialysis (CAPD), resulting in a lower serum level in uremic patients on CAPD than in those on hemodialysis. 3-Carboxy-4-methyl-5-propyl-2-furanpropionic acid was demonstrated in vitro to inhibit erythroid colony formation. The anemia in patients on CAPD was significantly less severe than in those on hemodialysis. These results suggest that the efficient removal by CAPD of 3-carboxy-4-methyl-5-propyl-2-furanpropionic acid, an inhibitor of erythropoiesis, is related to an improvement of anemia in patients on CAPD.

Adult↗

PubMed1990

Myelinated retinal nerve fibers: prevalence, location and effect on visual acuity.

We examined fundus photographs of 5,789 patients (11,578 eyes) and found 39 patches of myelinated nerve fibers in 35 eyes of 33 patients. The prevalence was 0.57%. The lesion was more frequent in females than in males. The patch occurred more often at the superior sectors of the nerve head and in the inferotemporal retina than in other areas. No myelinated nerve fibers were discovered in the macula. One patient (case 1) had 3 patches in 1 eye. Two patients (cases 2 and 3) had unilateral myelinated nerve fibers, bilateral myopia and ipsilateral amblyopia. In case 3, the patch was associated with an epiretinal membrane. Another patient (case 4) had branch vein occlusion and neovascularization from the patch of myelinated nerve fibers. The fundus conditions observed in our cases 1-4 may be uncommon.

Adolescent↗

PubMed1990

Trial of thyroid autotransplantation in patients with Graves' disease whose remnant thyroid has unintentionally been made too small at subtotal thyroidectomy.

Autotransplantation of thyroid tissue was carried out in 5 patients with Graves' disease in order to prevent postoperative hypothyroidism, because the amount of remnant thyroid tissue was estimated to be too small, i.e. from 3 to 5 g. Approximately 0.5 to 2 g of thyroid tissue was cut into small pieces and transplanted into the sternocleidomastoid muscles or the strap muscles. Although the postoperative serum TSH levels were normal or slightly elevated, the serum concentrations of triiodothyronine were within the normal range in these 5 patients at a follow-up study carried out 2 to 7 years after surgery. Thyroid scanning with I-123 or 99mTc-pertechnetate (Tc-99m) revealed radioisotope uptake at the sites of transplantation in 4 of the 5 patients. These findings verify that the implanted thyroid tissues were alive and functioning and that autotransplantation may be a way of preventing postoperative hypothyroidism in patients whose remnant thyroid tissue has unintentionally become too small.

Adult↗

PubMed1990

[The histopathological study of periodontal tissue regeneration using atelocollagen membranes].

In an attempt to promote periodontal tissue regeneration following periodontal surgery, an experimental study was conducted by applying the guided tissue regeneration (GTR) technique to a cross-linked atelocollagen membrane. The palatal gingiva of maxillary first molars of rats were dissected and the cementum was removed by curettage. An atelocollagen membrane was implanted into the site of dissection in the experimental group, while the control group received no implant. The wound healing processes in two groups were examined by histopathological methods, including histometric analysis of the cells and histological measurement of the regenerated periodontal tissue, 1, 3, 5, 7, 14 and 21 days, and 1, 2, 3 and 4 months after the implantation. The results were as follows. 1) Implantation of the atelocollagen membrane did not enhance or prolong the inflammatory reaction, indicating possible involvement of inflammatory cells and macrophages in the membrane absorption. 2) In the experimental group, epithelial downgrowth was markedly inhibited and fiber bundles of the gingival connective tissue were clearly arranged vertical to the root surface. 3) The experimental group showed a significant increase in new cementum formation 2 months after surgery compared with the control group. Root resorption was seldom observed in either group during the study period. The above results indicate that the GTR technique using an atelocollagen membrane may provide an effective method to promote periodontal tissue regeneration after periodontal surgery.

Animals↗

PubMed1990

[Effects of oxygen on growth of Streptococcus mutans].

Effects of oxygen on growth of Streptococcus mutans Ingbritt (serotype c) were examined. The strain could be passaged under aerobic conditions at 37 degrees C in a peptone/yeast extract medium containing 0.2% glucose. Although the growth rate was slightly retarded under aerobic conditions (the doubling time, 60 min; 45 min under anaerobic conditions), the increment of cellular dry weight change was 35 g per mole of glucose under both conditions. To investigate such aerotolerance in growth as indicated by these results, oxygen metabolism was compared between aerobically and anaerobically grown cells. No difference was observed in the apparent rate of superoxide production or superoxide dismutation. However, aerobically grown cells showed a higher activity of hydrogen peroxide reduction with glucose as substrate and accumulated a lower level of hydrogen peroxide when incubated with glucose under aerobic conditions. In addition, hydrogen peroxide added to the medium was less inhibitory to anaerobic growth when aerobic cells were used as the inoculum. These results indicate that aerotolerance of S. mutans Ingbritt can be ascribed at least in part to its hydrogen peroxide reducing activity which is elevated under aerobic conditions.

Hydrogen Peroxide↗