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Biomedical subjects

K Tada

Publications and source records attributed to K Tada.

At least 127 records · Page 7Linked to original sources

Multiple schwannomas in the radial nerve.

We present a case of multiple schwannomas in the radial nerve. The occurrence of multiple schwannomas in a single major nerve is very rare. Magnetic resonance imaging was useful in detecting the tumours. As schwannomas may be multiple without clinical symptoms, we recommend MR imaging of the entire limb when schwannomas occur in a major nerve in the upper extremity.

Adult↗

Role of screening for hepatitis C virus in children with malignant disease and who undergo bone marrow transplantation.

BACKGROUND: Children with malignant disease who received multiple blood transfusions before the clinical definition of hepatitis C virus (HCV) require evaluation for HCV infection. STUDY DESIGN AND METHODS: The role of HCV infection in 54 children with primary malignant disease was evaluated in terms of the following aspects: prevalence of HCV infection, distribution of HCV subtype, the benefit of screening of blood donors, and the presence of chronic liver disease. The benefit of screening for HCV in a subset of patients who underwent bone marrow transplantation (BMT) was also evaluated. RESULTS: Seventeen patients (31.4%) of 54 tested were seropositive in a second-generation HCV antibody test. Thirteen patients (24.0%) were also positive for circulating HCV RNA. HCV subtype 1b and HCV subtype 2b were found in six and two patients, respectively. Multiple HCV genotypes were present in two patients. One of these two patients had relatively progressive liver disease. Before the introduction of blood screening with a second-generation HCV antibody test, 15 of 35 patients seroconverted, whereas none of 7 patients seroconverted after the screening was used (p = 0.032). For patients who underwent BMT, the screening drastically decreased the seroconversion rate, from 7 of 11 patients to 0 of 6 (p = 0.016). CONCLUSION: A considerable number of children with primary malignant disease who received multiple blood transfusions became infected by HCV before HCV screening was used. Patients who underwent BMT were at high risk for HCV infection. Screening with a second-generation HCV antibody test has proven to be remarkably beneficial in preventing HCV infection in these children.

Adolescent↗

Nicotinamide derivatives as a new class of gastric (H+/K+)-ATPase inhibitors II. Synthesis and structure-activity relationships of 2[(2,4-dimethoxybenzyl)sulfinyl]-N-(4-pyridinyl)pyridine-3-carboxamides.

Members of a new series of 2-[(2,4-dimethoxybenzyl)sulfinyl]-N-(4-pyridinyl)pyridine-3-carboxamides were synthesized and evaluated for their gastric antisecretory activity and the ability to inhibit cytochrome P450-dependent O-dealkylation of 7-ethoxycoumarin (7-EC) in rat liver microsomes. Several of the compounds synthesized exhibited potent inhibitory activities against both [14C]aminopyrine accumulation stimulated by dibutyryl cyclic AMP in isolated rabbit parietal cells and histamine-induced gastric acid secretion in pylorus-ligated rats when administered intraduodenally; their inhibitory activities were equivalent to or superior to those of the parent compound [2- [(2,4-dimethoxybenzyl)sulfinyl]-N-(4-pyridinyl)pyridine-3-carboxamide] and omeprazole. Among the compounds having potent antisecretory activity in vitro and in vivo, 2-[(2,4-dimethoxybenzyl)sulfinyl]-N-(2,5-dimethyl-4-pyridinyl) pyridine-3-carboxamide and 2-[(2,4-dimethoxybenzyl)sulfinyl]-N-(2,6-dimethyl-4-pyridinyl)pyridine-3 - carboxamide in particular showed lower inhibitory activity against the 7-EC deethylase than omeprazole. It seems probable that, unlike omeprazole, these compounds do not interact with a metabolism of other drugs in vivo. These compounds, therefore, are considered to be more promising candidate agents for treating acid-related gastrointestinal disorders than the parent compound reported previously.

7-Alkoxycoumarin O-Dealkylase↗

Nicotinamide derivatives as a new class of gastric (H+/K+)-ATPase inhibitors. III. Synthesis and gastric antisecretory activity of 2-[(2- and 4-aminobenzyl, and alpha-methylbenzyl)sulfinyl]-N-(4-pyridinyl) -3-pyridinecarboxamides.

A new series of 2-[(2-aminobenzyl, 4-aminobenzyl, and alpha-methylbenzyl) sulfinyl]-N-(4-pyridinyl)-3-pyridinecarboxamides. was synthesized and evaluated for gastric antisecretory activities. Several of the compounds synthesized exhibited potent inhibitory activities against [14C]aminopyrine accumulation stimulated by dibutyryl cyclic AMP in isolated rabbit parietal cells and histamine-induced gastric acid secretion in pylorus-ligated rats by intraduodenal administration. In particular, the more polar diastereoisomer of 2-[(4-methoxy-alpha-methylbenzyl)sulfinyl] -N-(4-pyridinyl)-3-pyridinecarboxamide (13b) showed in vivo inhibitory activity equivalent or superior to that of omeprazole and was a more selective (H+/K+)-ATPase inhibitor than omeprazole.

Animals↗

Gestational thyrotoxicosis manifesting as wernicke encephalopathy: a case report.

The thyroid gland is physiologically stimulated in normal early pregnancy. This stimulated thyroid function is occasionally termed "gestational transient thyrotoxicosis". The cause of this thyrotoxicosis has been clarified to closely it associate with human chorionic gonadotropin (hCG). We encountered a pregnant patient with hyperemesis and thyrotoxicosis, who manifested symptoms of Wernicke encephalopathy. Although her serum hCG concentration transiently increased in accordance with the thyrotoxicosis, it was within normal limits for the gestational week. Both the thyrotoxicosis and a catabolic state due to the hyperemesis were thought to have induced a vitamin B1 deficiency, causing the Wernicke encephalopathy. This case suggests that pregnant patients with hyperemesis should undergo careful endocrinological and neurological evaluations.

Adult↗

Osteosynthesis for the treatment of non-union of the lateral humeral condyle in children.

We reviewed the results of osteosynthesis for the treatment of an established non-union of the lateral humeral condyle in sixteen children whose average age was nine years (range, four to thirteen years) at the time of the operation. The average interval between the injury and the operation was five years (range, five months to ten years). The presenting symptoms were pain in the elbow in seven patients, apprehension in nine, a cubitus valgus deformity in six, limitation of motion in three, and dysfunction of the ulnar nerve in four. The average duration of follow-up was eleven years (range, four to thirty-two years). Osseous union was achieved after the initial operation in thirteen patients. Of the three patients who had a persistent non-union, two had a second operation and the third, who was asymptomatic, refused additional operative intervention. The result was rated excellent in eight patients, good in seven, and poor in one, with use of a modification of the functional rating index of Broberg and Morrey. The patient who had a poor result had evidence of avascular necrosis of the fragment.

Adolescent↗

[A case of multifocal Langerhans cell granulomatosis: a BAL follow up study].

Langerhans cell granulomatosis, once called histiocytosis X, is a rare disease. A case of multifocal Langerhans cell granulomatosis in the bone, lymph nodes, skin and lungs of an 18-year-old man is described. Head CT and MRI showed a soft tissue mass of the left temporal bone. Lymph node and skin biopsies substantiated a diagnosis of Langerhans cell granulomatosis. A High resolution CT scan of the lung revealed a small cystic lesion, and bronchoalveolar lavage (BAL) showed an increased number of S-100 positive cells. Steroid therapy resulted in complete resolution, and no S-100 positive cells were obtained in the follow-up BAL study.

Adolescent↗

Bilirubin glucuronidation by intact Gunn rat fibroblasts expressing bilirubin UDP-glucuronosyltransferase.

Crigler-Najjar (CN) disease is an inherited disorder of bilirubin metabolism. The disease is caused by a deficiency of the hepatic enzyme bilirubin UDP-glucuronosyltransferase (B-UGT). Patients with CN disease have high serum levels of the toxic compound, unconjugated bilirubin. The only defect in bilirubin metabolism of CN patients is the absence of B-UGT activity. The transplantation of cells able to glucuronidate bilirubin should therefore lower serum bilirubin levels. The Gunn rat is the animal model of CN disease. Primary Gunn rat fibroblasts (GURF) were transduced with a recombinant retrovirus, capable of transferring B-UGT cDNA. A cell line was obtained expressing B-UGT at a level comparable to hepatocytes. Bilirubin added to the culture medium of these cells was glucuronidated and excreted. The B-UGT activities of transduced GURF and freshly isolated Wistar hepatocytes were compared at different bilirubin concentrations. The specific B-UGT activities of these two cell types were comparable when physiological bilirubin concentrations (5-10 microM) were present in the culture media. At higher bilirubin concentrations (20-80 microM) the hepatocytes were more active than the transduced GURF. We conclude that with the addition of only one enzyme (B-UGT) fibroblasts can perform the complete set of reactions necessary for bilirubin glucuronidation. The difference in B-UGT activity between transduced GURF and hepatocytes at 20-80 microM bilirubin can be explained by lower UDP-glucuronic acid and glutathione S-transferase levels in GURF. Our findings also indicate that these cells could be used to develop extrahepatic gene therapy for CN disease.

Animals↗

Platelet kinetics after transfusion.

A kinetics model is proposed for platelet disposition after transfusion of platelets. In this model, transfusion of platelets and production of endogenous platelets contribute to an increase in the number of platelets in patients, and the life span and age of each platelet contribute to a decrease. The time course of the number of platelets after transfusion of platelets is theoretically described by this model to be a straight line followed by a concave curve. When the platelets have a life span without any variation, a linear pattern is observed in spite of their different ages at the transfusion. This model with a constant life span was applied to three patients receiving platelet transfusion, and the model parameters were calculated by curve fitting the observed platelet levels to the model using the nonlinear least-squares method. As a result, the life span, distribution volume per body weight, and endogenous platelet level (averages for three patients) were calculated as 6.29 d, 0.137 L kg-1, and 1.40 x 10(4) counts microL-1, respectively. The calculated platelet levels in individual patients were compared with the observed ones during the next transfusions, and the relative and absolute differences between calculated and observed values were 2.0 +/- 15.3% and -0.075 +/- 0.443 x 10(4) counts microL-1 (mean +/- SD, 15 observed points for three patients), respectively. These case studies suggest that the model could be clinically useful for individual platelet transfusion.

Adult↗

Acute effect of beraprost sodium on lower limb circulation in patients with non-insulin-dependent diabetes mellitus-evaluation by color Doppler ultrasonography and laser cutaneous blood flowmetry.

The acute effects of beraprost sodium (sodium (+/-)-(1R*, 2R, 3aS*, 8bS*)-2, 3, 3a 8b-tetrahydro-2-hydroxy-1-[(E)-(3S*)-3-hydroxy-4-methyl-I- octen-6-ynyl] -1H-cyclopenta [b] bensofuran-5-butyrate), a stable analogue of prostaglandin I2 which works as a vasodilator and anti-platelet agent, were investigated in patients with non-insulin dependent diabetes mellitus. Its effects on the dorsal pedis artery were examined using a new real-time two-dimensional Doppler ultrasonographic technique and by laser blood flowmetry. Before and 60 min after oral administration of beraprost sodium (Dolner 40 micrograms) and elastase (Elaszym 1800 U), the cross-sectional area (CSA) of the dorsal pedis artery and its blood flow index (BFI), calculated from the maximum flow velocity and area, were determined. Dermal microcirculatory blood volume (MBV) was also measured by laser blood flowmetry. In the beraprost sodium group, the CSA, BFI and MBV were significantly increased, while in the elastase group, no significant changes were observed. These result suggest that beraprost sodium has a beneficial effect on diabetic macro- and microangiopathy.

Arteries↗

Independent index extension after indicis proprius transfer: excision of juncturae tendinum.

Isolated extension of the index finger after extensor indicis proprius (EIP) transfer was studied. In cadavers, the extensor digitorum communis (EDC) muscle of the index finger received distinct innervation from the posterior interosseous nerve and was well separated, with its own innervation, from the other EDC muscle. Examination of von Schroeder's type I juncturae tendinum (JT) between the index and long finger showed two types: von Schroeder type IA (16 of 27 hands; 59%) was fascia only; von Schroeder type IB (11 of 27 hands; 41%) was thin filamentous bands. In clinical cases, 3 hands were type IA and 10 were type IB. Retained independent index finger extension was obtained in all patients with excision of the JT between the index and long finger following EIP transfer.

Adolescent↗

Soybean protein suppresses hepatic lipogenic enzyme gene expression in Wistar fatty rats.

The effects of dietary soybean protein on lipogenic enzyme gene expression in livers of genetically fatty rats (Wistar fatty) have been investigated. When Wistar fatty rats and their lean littermates (7-8-wk old) were fed a casein or soybean protein isolate diet containing hydrogenated fat (4% hydrogenated fat plus 1% corn oil) or corn oil (5%) for 3 wk, the hepatic messenger RNA concentrations and activities of lipogenic enzymes were significantly lower in rats fed soybean protein than in those fed casein, regardless of genotype or dietary fat. The conversion rates of thyroxine to triiodothyronine by liver microsomes and plasma triiodothyronine concentrations were lower in the fatty rats than in the lean rats and were significantly greater in rats fed soybean protein than in those fed casein. Conversely, plasma and liver triacylglycerol concentrations were lower in soybean protein-fed fatty and lean rats than in those fed casein. The body weight was less in the fatty rats fed soybean protein than in those fed casein after 3 wk of feeding. Moreover, dietary polyunsaturated fatty acids suppressed lipogenic enzyme gene expression in the lean rats but did not in the fatty rats. Dietary soybean protein appeared to be useful for the reduction of obesity.

ATP Citrate (pro-S)-Lyase↗

Nutritional regulation of lipogenic enzyme gene expression in rat epididymal adipose tissue.

The time courses of gene expression, and the nutritional regulation of gene expression of lipogenic enzymes (acetyl-CoA carboxylase, fatty acid synthase, ATP citrate-lyase, malic enzyme, and glucose-6-phosphate dehydrogenase) in epididymal adipose tissue after refeeding food-deprived rats have been investigated and compared with those in liver (previously reported). The mRNA concentrations of lipogenic enzymes reached maximum levels at 24 h after the refeeding in adipose tissue and at 8-16 h in liver, while the enzyme induction reached maximum at 48-72 h in both tissues. Moreover, the mRNAs were more strongly induced in adipose tissue than in liver, whereas the enzyme induction (except malic enzyme) was lower. In adipose tissue of rats fed a carbohydrate diet without protein, the mRNA concentrations of acetyl-CoA carboxylase, ATP-citrate lyase, malic enzyme, and fatty acid synthase reached comparable levels to those of the carbohydrate/protein diet group. The protein feeding increased the enzyme induction in adipose tissue. As regards reduction of gene expression, lipogenic enzyme mRNA concentrations were not so markedly reduced by starvation or polyunsaturated fatty acids in adipose tissue as in liver. The differences in regulation of lipogenic enzyme gene expression and induction between adipose tissue and liver can be ascribed to tissue specificity.

ATP Citrate (pro-S)-Lyase↗

Synthesis of secretory protein in regenerating liver of rat after partial hepatectomy.

Albumin immunoreactivity in the liver was examined on days 2, 5 and 10 after two-thirds partial hepatectomy by light and ultrastructural immunoperoxidase methods and the ultrastructural area of the rough endoplasmic reticulum (ER) in hepatocytes was measured. Albumin immunoreactivity was seen in the rough ER and Golgi apparatus of all hepatocytes in the hepatectomized liver and ultrastructural analysis showed a significantly greater area of rough ER on day 5 than on days 2 or 10. Albumin mRNA was studied by the in situ hybridization technique using radioisotopes and their numbers were determined visually. Albumin mRNA was present as grains in all hepatocytes and the grains varied in number during regeneration of the liver, being more abundant on day 5 than on days 2 or 10. The activity of [3H]-leucine incorporated into albumin synthesis, an indicator of translational activity, was higher on days 5 and 10 than on day 2 and was highest on day 5. In conclusion, albumin synthesis varied during liver regeneration after partial hepatectomy, being reduced at the peak of cell proliferation on day 2 and being most active on day 5.

Albumins↗