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T Kodama

Publications and source records attributed to T Kodama.

At least 757 records · Page 42Linked to original sources
PubMed1988

Stopped-flow calorimetry of myosin ATP hydrolysis: an implication of chemomechanical energy transduction.

Measurements were made of heat production in the pre-steady state phase of ATP hydrolysis by myosin subfragment 1 using an improved stopped-flow calorimeter. This instrument can measure temperature changes as small as 3 X 10(-4) K with a thermal response time of less than 10 ms. When SF-1 was mixed with ATP at 0 degrees C, there was a fairly rapid heat absorbing phase (rate constant, 20-25 s-1 at pH 8) after a burst of heat production was complete within the dead time of the instrument (10 ms). Then followed a phase of very slow heat production with a heat rate of 7 kJ/mol/s. This result indicates that the ATP binding to SF-1 is an exothermic process whereas the subsequent isoenergetic splitting of ATP on the myosin site is endothermic. Thus, a decrease in the internal energy drives the ATP binding which may be regarded as the chemical energy trapping process. By contrast, the myosin intermediate with hydrolysis products (ADP + Pi) is stabilized by a large increase in entropy. In energy transduction by myosin/actin system of muscle, therefore, switching of chemical energy into a form available for mechanical work would be a transition from a low entropy to a high entropy state of weakly actin binding conformations of myosin.

Adenosine Triphosphatases↗
PubMed1988

[AUFRAP therapy: combined modality treatment of malignant gliomas with intraarterial infusion of ACNU].

A method of combination therapy was proposed for the treatment of malignant gliomas, and the clinical results were reported. This combination consisted of ACNU (nimustine), UFT (tegafur + uracil), Radiation, vitamin A and PSK (krestin), and was named AUFRAP therapy. Intracarotid infusion of ACNU (100 or 150 mg/body) was done after the administration of vitamin A (100,000 units), in the first and last week of radiation therapy with a total dose of 60-70 Gy. UFT (400-600 mg/day) and PSK (3g/day) were also given orally. After the induction of remission, patients were treated in the outpatient clinic under a similar maintaining protocol. Two patients who received 150 mg of ACNU and daily 600 mg of UFT in combination with radiation therapy showed severe myelosuppression in the early stage of treatment, and the combination therapy was aborted. Two of four patients who received 100mg of ACNU and daily 400mg of UFT did not show such severe side effects and two showed transient, moderate myelosuppression and vomiting. The serum phenitoin concentration doubled and was thought to be a side effect of tegafur. All four patients completed the induction protocol and follow-up CT scans disclosed shrinkage of the remained tumors, decreased contrast enhancement or no evidence of recurrence. Interactions of these drugs and radiation were discussed and the literature was reviewed.

Adult↗
PubMed1988

High molecular weight aggregate from cataractous and normal human lenses: characterization by antisera to lens crystallins.

High molecular weight and low molecular weight fractions were obtained from total soluble proteins of human cataractous and normal lens nuclei. These fractions were analyzed using a solid phase radioimmunoassay that employed monospecific antisera to alpha, beta and gamma crystallins. Relative to the high molecular weight fraction from normal lens nuclei, the high molecular weight fraction from cataractous lens nuclei showed decreased binding to antisera specific for beta and gamma crystallins. These results demonstrate that the polypeptides of the high molecular weight fraction comprise a special class of polypeptides that have preferentially undergone covalent and/or structural changes during the process of human cataractogenesis.

Cataract↗
PubMed1988

C cell adenoma of the thyroid: a rare but distinct clinical entity.

Although the benign counterpart of medullary carcinoma of the thyroid has never been indicated in textbooks, we propose that C cell adenoma is a rare but distinct clinical entity. Two patients, a 43-year-old man and a 53-year-old woman, had similar thyroid tumors, both about 4 cm in diameter. The cut surfaces of the resected tumors were indistinguishable from a common microfollicular adenoma of the thyroid. Microscopically, the tumors were uniformly composed of fusiform cells without any follicle formation. Neither amyloid deposition nor calcification was found. Although some kind of C cell tumors were suggested, the exact nature was debatable. However, extremely high levels of calcitonin (1330 and 2065 pg/ml, respectively; normal level, less than 170 pg/ml) were found in the stored sera taken preoperatively. Serum levels of carcinoembryonic antigen (CEA) were normal in both patients. Immunohistochemically, the tumor tissues were positive for calcitonin and neuron-specific enolase but negative for CEA with a monoclonal anti-CEA antibody. No somatostatin, glucagon, or adrenocorticotropic hormone activity was found. It is highly probable that such tumors have not been closely studied and have been regarded as eccentric adenomas of the thyroid or simply as the so-called medullary carcinomas of the thyroid.

Adenoma↗
PubMed1988

[A case of radiation induced aneurysm of extracranial carotid artery].

An unusual case of post-irradiation aneurysm of extracranial internal carotid artery is presented. A 70-year-old man, complaining of left cervical throbbing mass with focal pain, was admitted on February 8, 1985. It was noted, from his past history, that he had had surgery of the removal of cervical lymph-nodes and that unknown dosage of irradiation had been added to the cervical region 30 years before. Left carotid angiography (on admission) demonstrated a giant aneurysm in the cervical portion of internal carotid artery. Right carotid angiography with compression of left carotid artery revealed good cross filling through anterior communicating artery. Computed tomography with contrast media showed a ring like enhanced mass, which was thought to showed a ring like enhanced mass, which was thought to suggest that a large part of the aneurysm was filled with intraluminal thrombosis. During 30 days of evaluation, the aneurysm grew larger and his cervical pain became untolerable. Operation, the resection of the aneurysm and the reconstruction (of circulation) with vein graft, was challenged n March 12. It was so difficult with meticulous work that the ligation of left common carotid artery was performed after all. Seven days after the operation, he suffered from the gastrointestinal bleeding, which was enough to lead him to hypovolemic shock. Thereafter, right hemiparesis and aphasia were brought about. Two months later, he die of pneumonia.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1988

[Experimental study on the development of endotoxemia in biliary tract infection with special reference to lymphatic pathway at controlled biliary duct pressure].

A study was made on the pathway of the endotoxin from the biliary tract into the circulation, using adult mongrel dogs divided into 10 groups primarily with or without thoracic duct drainage. The biliary duct pressure level of 25, 35, and 55 cm saline was maintained by infusing physiological saline into the bile duct. Each level was maintained for a 10-minute period following the intrabiliary infusion of endotoxin 10 mcg/kg. The endotoxin level in arterial and portal blood and in thoracic lymph increased with increment of biliary duct pressure. The endotoxin level in the thoracic lymph was more than 10 times higher than that in blood. At 35 and 55 cm saline of biliary duct pressure, the groups with or without thoracic lymph drainage did not show any significant difference in blood endotoxin level, or moreover, endotoxin shock developed in each group. These findings imply that at high biliary pressure such as 35 or 55 cm saline, endotoxin in the bile duct directly appears in the sinusoid. At low biliary pressure such as 25 cm saline, endotoxin was detected only in thoracic lymph and endotoxemia did not develop.

Acute Disease↗
PubMed1988

Characterization of disulfide-linked crystallins associated with human cataractous lens membranes.

In order to characterize possible disulfide-linked interactions between lens fiber cell membranes and crystallins, two-dimensional diagonal electrophoresis has been used in combination with Western blot analysis. When these blots were probed with monospecific antisera against alpha, beta and gamma crystallins, membrane from five individual normal lenses showed no disulfide-bonded components. Membrane from 13 individual cataractous human lenses showed no disulfide-bonded alpha crystallin, but did show significant amounts of disulfide-bonded beta crystallin in four out of the 13 lenses studied, and significant amounts of disulfide-bonded gamma crystallin in 10 out of the 13 lenses studied. Together, these studies demonstrate that intermolecular disulfide bonding of crystallins to purified fiber cell membranes is found only in cataractous lenses, and that the predominant polypeptide species involved in this interaction is gamma crystallin.

Cataract↗
PubMed1987

Structural abnormality and over-expression of the myc gene in feline leukemias.

Tumor cells of feline leukemia were examined for structural abnormality and expression of the myc gene. Four of 12 spontaneous leukemia cases showed structural abnormalities of the myc gene detected by Southern blotting analysis. Of these 4 cases, one (Case 1) showed a DNA rearrangement in the 5' portion of the c-myc locus associated with integration of feline leukemia virus (FeLV) genome. Another case had a newly inserted myc gene which was transduced by FeLV. In the 2 other cases, no relation of abnormalities of the myc gene to FeLV was detected. One case of experimental leukemia induced by inoculation of a cell line, FT-1, established from Case 1 showed a c-myc gene rearrangement similar to that observed in Case 1. Expression of myc RNA was examined in 3 leukemia T-cell lines, FT-1, FL74 and F422, by Northern blotting analysis. A high level of myc transcript was detected in all 3 cell lines. The size of myc RNAs in FT-1 and FL74 was the same as that of normal myc RNA, while in F422 which had myc-containing FeLV (myc-FelV), the full genome and spliced form of myc-FeLV viral RNA were detected.

Animals↗