Search PubMed⌕ Search

Biomedical subjects

T Kumamoto

Publications and source records attributed to T Kumamoto.

At least 145 records · Page 8Linked to original sources
PubMed1990

[A case of thymic carcinoma].

A 41-year-old male visited with chief complaints of chest pain and cough. The patient was operated on under a diagnosis of invasive thymoma. The tumor was located in the left lobe of the thymus and measured 6 X 9 cm. Since the tumor invaded the left innominate vein, pericardium, and the upper lobe of the left lung, we resected it with adjacent structures. Postoperative pathological examination indicated squamous cell carcinoma of the thymus. Because the tumor metastasized also to the mediastinal lymph nodes, the patient was treated postoperatively by radiation therapy and adjuvant chemotherapy mainly with CDDP. The patient is well presently 2 years after operation without signs of recurrence.

Adult↗
PubMed1990

[Effects of short- and long-term administration of ritodrine on spontaneous contractions of longitudinal muscle strips dissected from the pregnant rat uterus].

We investigated the effects of Ritodrine (10(-10)-10(-7) g/ml) on spontaneous contractions of rat myometrium at gestational days 14, 16, 18 and 21. 1. More than 10(-8)g/ml Ritodrine obviously suppressed the spontaneous contractions more than smaller doses. The inhibitory effects of smaller doses on days 14 and 16 were different from those on days 18 and 21, the former being more effective. 2. Smaller doses of Ritodrine (10(-10)-10(-8)g/ml) caused transient excitation, which was inhibited by pretreatment with Phentolamine. 3. Rebound excitation was observed in most of the specimens. 4. Spontaneous contractions reappeared during long-term administration of Ritodrine and the patterns could be classified into three types. These results suggested that the effects of Ritodrine might vary according to the number of pregnant days and that the critical Ritodrine dose for a suppressive effect is 10(-8)g/ml, and there are a transient alpha-excitatory effect, rebound excitation and three types of suppression as a result of long-term administration.

Animals↗
PubMed1989

Gastrin receptors in the human gastrointestinal tract and pancreas.

The specific binding of 125I-labeled gastrin-17 was studied in samples of human gastric mucosa, duodenal mucosa, colonic mucosa or pancreatic tissue obtained surgically. With regard to gastric fundic mucosa, the criteria for receptor binding were studied, and saturability, high affinity, tissue specificity and hormone specificity were demonstrated. The dissociation constant for gastric fundic mucosa was 1.6 X 10(-9)M, and the binding capacity was 15 fmol/mg protein. Tissue specificity studies revealed a high degree of gastrin receptor binding in human gastric fundic mucosa, duodenal mucosa and pancreas, whereas antral mucosa and colonic mucosa demonstrated a low degree of binding.

Binding Sites↗
PubMed1989

Critical region in the extension peptide for the import of cytochrome P-450(SCC) precursor into mitochondria.

In order to establish the role of the extension peptide of the precursor of P-450(SCC), a mitochondrial inner membrane protein, in the import into the organella, three deletion mutants of the precursor, in which the deletions were in the mature portion, were constructed. These mutant precursors were imported into mitochondria in vitro as efficiently as the original precursor, indicating that the extension peptide contains sufficient information for the import of the precursor into mitochondria. To investigate which portion of the extension peptide contains the mitochondrial targeting signal, various lengths of the amino-terminal portion of the extension peptide of P-450(SCC) precursor were fused to the mature portion of adrenodoxin. The fusion proteins consisting of 44 and 19 amino-terminal amino acids and mature adrenodoxin were imported into mitochondria, whereas those containing 14, 7, and 2 amino-terminal amino acid residues were not. The importance of the amino-terminal portion of the extension peptide was confirmed by the deletion from the amino-terminal end of a fusion protein consisting of the amino-terminal 44 amino acid residues of P-450(SCC) precursor and mature adrenodoxin, SCC44RAd. The amino-terminal deletions abolished the import of the fusion proteins into mitochondria. Substitution of all of the three basic amino acids, Arg(4), Arg(9), and Lys(14) in the extension peptide of SCC44RAd to Ser or Thr inhibited the binding of the fusion protein to mitochondria as well as its import.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenodoxin↗
PubMed1989

Experimental chloroquine myopathy: morphological and biochemical studies.

Morphological and biochemical studies were performed on the soleus muscles of rats receiving a daily intraperitoneal injection of 50 mg chloroquine chloride (CQ) per kilogram of body weight. Light microscopy showed mild to moderate variations in fiber size, numerous dense membranous bodies and vacuoles. The vacuoles were ringed by material that was intensely basophilic in hematoxylin-eosin preparations, resembling rimmed vacuoles in the muscle fibers of distal myopathy. Segmental degradation or necrosis was often observed. The 3H-leucine uptake by myofibrillar and soluble sarcoplasmic fractions in CQ-treated muscles was the same as in the controls. The significant increases in lysosomal (cathepsin B & L, B and D) proteases and thiol protease inhibitor occurred in the earlier stages of CQ-induced myopathy, when hardly any autophagic vacuoles or dense bodies were observable by light microscopy. We conclude that the over-development of autophagic vacuoles and the significant increases in lysosomal protease activity in muscle tissues may be important in the development of the focal degradation and necrosis of CQ-treated muscles.

Animals↗
PubMed1989

[A case of malignant rheumatoid arthritis with severe peripheral neuropathy].

A 72-year-old woman of definite type of malignant rheumatoid arthritis (MRA) with severe peripheral neuropathy. She has often noted pain of both shoulders or knee joints since some years ago. At the age of 71, she noticed numbness of the feet with pain and swelling of knee joints. She was diagnosed as definite type of rheumatoid arthritis by one podiatrist. Although she took some medications, she subsequently developed general fatigue, appetite loss, exacerbation of arthritis, drop feet and hands with prominent coldness. She was admitted to our hospital on March 22, 1985. On examination, she revealed purpura, decubitis, heart murmur, arthritis of knee joints, and fingers necrosis with skin ulcer. She had severe muscle weakness, and wasting of four limbs. Moderate impairment of all-modality sensations were noted in all extremities. Distal involvement was greater than proximal. Laboratory data during administration of prednisolone (60 mg/day) were as follows: glucose in urine, 2+; occult blood in urine, 1+; white blood cells count, 18600 with 92% polymorphonuclear leukocytes; erythrocyte sedimentation rate, 60 mm in an hour; CRP, 14.62 mg/dl (normal 0.5 greater than); RA test, 2+; RAHA, 10240; CH50, 10 U/ml (normal 32-42); C3, 37 mg/dl (normal 55-75); C4, 9 mg/dl (normal 15-28); immune complex, 4.4 micrograms/ml (normal 3.0): Chest X-ray film showed cardiomegaly (CTR, 57%). ECG disclosed atrial premature contraction, and echo cardiography suggested epicarditis with aortic valve insufficiency. 99mTc RI angiogram revealed impairment of peripheral circulation. SCV on sural nerve was not elicited. Sural nerve biopsy showed obliterans type of endoarteritis and axonal degeneration with loss of myelinated fiber.

Aged↗
PubMed1989

[Treatment of the infected emphysematous bulla].

From 1985 to 1987, we had 4 patients with infected emphysematous bulla, three males and one female ranging from 18 to 61 years of age. The male patients had been suffering from emphysematous bullae and had complications stemming from the resulting infection. In the female case, the infection occurred at the pneumatocele which had grown at pneumonia was caught during steroid therapy for SLE. While all cases were medicated with antibiotics intravenously, they were drained with a small caliber tube percutaneously, then were washed using a cytocidal agent (dilute povidone iodine). In two cases, an infected emphysematous bulla and an infected pneumatocele cleared, then shrank and closed. In the remaining cases, the infected emphysematous bullae also cleared and shrank, then the patients underwent operations. All patients then healed. The therapeutic combination of percutaneous drainage with a small caliber tube and washing of infected emphysematous bulla is available for therapy or preoperative treatment for the following reasons: First of all, especially in patients who have remarkably disturbed pulmonary function, it can be performed safely and pt's symptoms and the general condition of the patient improves rapidly. The second reason is that, in some particular cases, it achieves the remarkable shrinkage and closure of infected emphysematous bulla. The third reason is that, the patients experience minimum pain with the use of a small caliber drainage tube.

Adolescent↗
PubMed1988

Gastrin receptors in human gastric scirrhous carcinoma.

Specific binding of 125I-labeled gastrin-17 in tumor tissues and gastric mucosa of 11 advanced human gastric carcinoma cases were studied by single-point receptor assay, using 400 pM 125I-labeled gastrin-17. Membrane preparations (800-15,000 g fraction) of the tissues were examined in this study. In 4 of the 5 cases of gastric scirrhous carcinoma (Borrmann type IV), the tumor tissues showed a high degree of specific bindings (1.1-18.2 femtomoles per milligram protein), but in 5 of the 6 cases of Borrmann type II or III, no specific bindings were detected. These findings indicate that gastrin receptor is frequently present in human gastric scirrhous carcinoma.

Adenocarcinoma, Scirrhous↗
PubMed1987

Site-directed mutagenesis of basic amino acid residues in the extension peptide of P-450(SCC) precursor: effects on the import of the precursor into mitochondria.

The precursor of cytochrome P-450(SCC) (preP-450(SCC], an inner membrane protein of adrenal cortex mitochondria, has an extension peptide consisting of 39 amino acids which is thought to play an essential role in the import of the precursor into mitochondria. The amino terminal portion of the extension peptide contains three positively charged amino acid residues, Arg(4), Arg(9), and Lys(14). To investigate their role in the import of preP-450(SCC) into mitochondria, they were replaced by other amino acids, Ser or Thr, by site-directed mutagenesis. The import of mutated preP-450(SCC)s with single amino acid substitution was much less efficient than with the original precursor. The mutated preP-450(SCC)s with two or three substitutions were not imported. These results suggest that the positively charged amino acid residues in the amino terminal portion of the extension peptide are essential for the import of preP-450(SCC) into mitochondria.

Amino Acids↗
PubMed1987

Prevalence studies of multiple sclerosis, myasthenia gravis, and myopathies in Kumamoto district, Japan.

The prevalence ratio per 100,000 population of each disease was multiple sclerosis (MS) 1.3, myasthenia gravis (MG) 6.7, and polymyositis (PM) 5.0 in Kumamoto city, Japan (population 0.56 million, and the survey date on June 30, 1982). The prevalence ratio of MS was similar to that of 25 years ago in Kumamoto city. The incidence of MS had been stable despite Westernization of life-style in Japan. The prevalence ratio of MG and PM had increased moderately, possibly due to prolongation of life with recent progress in therapy. The prevalence ratio of all types of myopathies in Kumamoto prefecture (population: 1.8 million) on July 31, 1983, was estimated as approximately 17.4 per 100,000, for progressive muscular dystrophy (PMD) 4.1 per 100,000 population, compared to 3.9 for MG, and 2.4 for PM. The relative frequency of PMD, MG and PM was 23.3, 22.0 and 13.9%, respectively. The data shows that the prevalence ratio of various myopathies has not changed over the last 20 years in selected cities of Japan but the relative frequency of the diseases have changed due to recognition of the disease and prolongation of long life due to developments in diagnosis and treatment.

Adolescent↗
PubMed1986

Characterization of a mitochondrial matrix protease catalyzing the processing of adrenodoxin precursor.

Adrenodoxin (Ad) is synthesized as a larger precursor (preAd) by cytoplasmic polysomes and then transported into mitochondria concomitant with its proteolytic processing to the mature form. The protease in bovine adrenal cortex mitochondria, which converts preAd to the mature form, is a metalloprotease in the matrix (Sagara, Y., Ito, A. & Omura, T. (1984) J. Biochem. 96, 1743-1752). In this study, the protease was purified about 100-fold from the matrix fraction of bovine adrenal cortex mitochondria. The partially purified protease converted not only preAd, but also the precursors of malate dehydrogenase (MDH) and 27 kDa protein (P-27) to the corresponding mature forms. However, it was inactive toward the precursors of P-450(SCC) and of P-450(11 beta). Since isolated rat liver mitochondria can import and process preAd as efficiently as bovine adrenal cortex mitochondria, we partially purified a preAd-processing protease from rat liver mitochondria and compared its properties with those of the bovine adrenal cortex enzyme. The properties of the rat liver protease were indistinguishable from those of the bovine adrenal cortex enzyme in molecular weight determined from Sephadex G-150 gel filtration, metal requirement and ability to process preMDH and preP-27. The rat liver enzyme was also inactive toward the precursors of P-450(SCC) and P-450(11 beta). These results indicate the presence in both adrenal cortex and liver mitochondria of the same type of processing protease, which processes preAd and also the precursors of some other mitochondrial proteins.

Adrenal Cortex↗
PubMed1986

Experimental neuropathy induced by methyl mercury compounds: autoradiographic study of GABA uptake by dorsal root ganglia.

Methyl mercury chloride (MMC, 10 mg/kg body weight/day) was subcutaneously injected into rats for 1 week. Animals were killed at 5 or 14 days (at the onset of clinical symptoms) after injection of MMC. Morphologically, most of the myelinated fibers in peripheral nerves showed axonal degeneration. Ganglion cells showed histopathological changes similar to those in previous reports. The cytoplasm of satellite cells stained dark with toluidine blue and was narrow, and sometimes showed focal disappearance of rough endoplasmic reticula, ribosomes or filaments. Autoradiography in the control rats showed that 3H-GABA was exclusively localized within the satellite cells and Schwann cell cytoplasm of the myelinated fibers and was not revealed within the ganglion cells. The number of silver grains markedly decreased in the satellite cells of the MMC-treated rats. 14C-GABA uptake by dorsal root ganglia also decreased to 75.0% of the control on the 5th day and to 49.2% on the 14th day. Therefore, MMC was found to inhibit greatly the GABA uptake into the satellite cells in the earlier stage of poisoning, and was considered to affect primarily the satellite cells and Schwann cells as well as the ganglion cells.

Animals↗