Biomedical subjects
Publications and source records attributed to T Hata.
We treated a patient with primary vaginal carcinoma. Very valuable preoperative diagnostic imaging of the carcinoma obtained by transvaginal color Doppler and magnetic resonance is reported herein.
Transvaginal color and pulsed Doppler ultrasound examinations were made on 40 patients to assess hemodynamics in the pelvis. Use of a special probe for transvaginal scanning led to superb simultaneous visualization of structures and blood flow, and we noted various events, even in the small, deep and/or peripheral vessels. Some but not all of the observations were in agreement with the results obtained using transabdominal color and pulsed Doppler ultrasound. We propose that transvaginal color and pulsed Doppler ultrasound be considered for routine use to determine physiological and pathological events in the female pelvis.
Two new derivatives of glycosyl mitomycin C, 7-N-[4-O-(beta-D-glucopyranosyl and alpha-sialosyl)phenyl]-9a- methoxymitosanes, were synthesized, and their structures were elucidated by analysis of the nuclear magnetic resonance spectra. Field desorption mass spectrometry was successfully used for the confirmation of these structures. The cytotoxic, antibacterial, and antitumor activities of 7-N-(4-glycosylphenyl)-9a- methoxymitosanes were also examined.
(2R,5S)-2-Hydroxymethyl-1-carbapenam (3), the carba-analog of an antifungal beta-lactam (2R,5S)-2-(hydroxymethyl)calvam (1), was synthesized in an enantiocontrolled manner, starting from the coupling reaction of an optically active phthalimido-acetate (3S,4S)-4 and an allylsilane 7, followed by removal of the phthalimido group that was crucial for asymmetric induction. Hydroboration, protecting-group interconversion, and cyclization gave 3 stereoselectively.
Central nervous system levels of serotonin (5-HT) and 5-hydroxy-indoleacetic acid (5-HIAA) in SART (specific alternation of rhythm in temperature)-stressed (repeatedly cold-stressed) rats were examined by HPLC-ECD. In SART-stressed rats, the levels of both 5-HT and 5-HIAA decreased in many brain areas. In the spinal cord, only the 5-HT level decreased. Therefore, the ratio of 5-HIAA to 5-HT increased only in the spinal cord. These results suggest that SART-stressed rats have some form of abnormality in the synthetic system of 5-HT.
Blood coagulation and fibrinolytic activity was studied in SART (specific alternation of rhythm in temperature)-stressed animals found to exhibit thrombocytopenia and prolonged bleeding time, and drug effects on the abnormalities were evaluated. 1) SART-stressed rats revealed prolongation of activated partial thromboplastin and thrombin time, no change in prothrombin time, decreased plasma fibrinogen levels, and shortened euglobulin clot lysis time (ELT). Antithrombin III and alpha 2-plasmin inhibitor activity remained constant following stress exposure. 2) During stress, fibrinogen levels declined from day 5 and remained depressed up to day 14. Reduction in ELT developed in a similar manner to fibrinogen. 3) Decreased fibrinogen levels were prevented by consecutive doses of tranexamic acid, an antifibrinolytic, and Neurotropin, a sedative analgesic. Shortened ELT was counteracted by chronic treatment with Neurotropin and alprazolam, an anxiolytic. Single administrations of the above agents failed to affect either change. These results indicate that SART-stressed animals exhibit suppressed intrinsic coagulability and enhanced fibrinolytic activity, but normal extrinsic coagulability. Considering the previous report together with the above results, the hemostatic system under SART stress tends uniformly toward hemorrhage. Moreover, Neurotropin appears to improve and normalize hemostatic imbalance due to SART stress, a chronic form of stress.
Exposing mice to 24 and 4 degrees C in alternate 1 hr periods in the day time and maintaining 4 degrees C at night for several days decreases the tail clamp pressure required to evoke pain behavior. This model is referred to as SART (specific alternation rhythm of temperature) stress. An extract from inflamed skin of rabbits inoculated with vaccinia virus (neurotropin) clearly normalized the hyperalgesia in this SART stress model. To clarify the mechanism of the hyperalgesia in SART mice and the mode of the antinociceptive action of neurotropin in this model, the influence of systemically administered neurotransmitter related drugs was studied. 1) Neurotropin, 5-hydroxytryptophan and L-dihydroxyphenylalanine significantly normalized the decrease in nociceptive threshold, and muscimol tended to inhibit it in nociceptive threshold in SART stressed mice. 2) Haloperidol, phenoxybenzamine, reserpine, bicuculline, scopolamine, physostigmine and naloxone alone did not influence the nociceptive threshold in SART stressed mice. 3) The antinociceptive effect of neurotropin was significantly attenuated by p-chlorophenylalanine, haloperidol and phenoxybenzamine; and it was completely inhibited by reserpine. 4) Naloxone, bicuculline, scopolamine and physostigmine had no influence on the antinociceptive effect of neurotropin. These results suggest that hypofunction mainly of the monoaminergic systems contributes to hyperalgesia in SART stressed mice and that neurotropin produces the antinociceptive effect by restoring these neural functions.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
We investigated the ability of Rossavik growth models, determined from measurements obtained before 24 weeks (head circumference [HC], abdominal circumference [AC], femur diaphysis length, and estimated fetal weight [EFW]) or 25 weeks (thigh circumference), to predict third-trimester growth and birth characteristics in normally growing triplets. Comparisons of coefficient c values for six anatomical measurements indicated no statistically significant differences in the second-trimester growth of triplets, twins, and singletons. Third-trimester triplet values for HC, AC, and femur diaphysis length were predicted with an accuracy of +/- 6-8%. For thigh circumference and EFW, the comparable values were +/- 17 and +/- 15%, respectively. The HC at birth was predicted without bias; the random error was approximately -27 to 9.0%. Weight, AC, and thigh circumference were systematically overestimated (16.5, 20.9, and 16.3%, respectively). After correction for systematic errors, these characteristics could be predicted with random errors of -13.0 to 9.5% (weight), -12.0 to 2.8% (AC), and -16.7 to 11.3% (thigh circumference). Growth Potential Realization Index values had means of approximately 100% and ranges from 90-121%. The mean triplet value of the Neonatal Growth Assessment Score was 13.6, ranging from 2.8-26.5. These results are similar to those for singletons and twins and indicate that individual assessment of growth in triplets can be performed with the same methods used for both singletons and twins.
Lateral medullary syndrome is known to cause hemiparesis ipsilateral to the medullary lesion. However, it's clinical significance has not been fully evaluated. In this study, we made clinical and angiographic studies in patients with syndrome to elucidate the pathogenesis of ipsilateral hemiparesis. Thirty-four patients with cerebral infarction presenting with this syndrome were studied. Their mean age was 51 years and all the patients were examined within 6 months of their first attack. Diagnosis of ipsilateral hemiparesis was made if subjective feeling of weakness in the upper and lower extremities was associated with increased deep tendon reflexes. Ipsilateral hemiparesis was observed in 38% of all the patients. Cerebral angiography was performed in 26 patients and divided into two groups; group A with ipsilateral hemiparesis (n = 9) and group B without ipsilateral hemiparesis (n = 7). In 56% of patients in group A, angiography showed non-visualization of ipsilateral vertebral artery (VA) and posterior inferior cerebellar artery (PICA). Non-visualization of these two arteries never occurred in the patients of group B. On the other hand, non-visualization of VA alone was observed in 35% of the patients in group B, but it was none in the patients of group A. However, there were no differences in concerning the frequency of non-visualization of PICA alone or non-occlusion at all between both groups. Therefore, the focal ischemia in the region below the pyramidal decussation due to the occlusion of both VA and PICA, regardless of thrombotic or embolic episode, was considered to be responsible for ipsilateral hemiparesis.(ABSTRACT TRUNCATED AT 250 WORDS)
Because valve thrombosis occurred after the tricuspid valve replacement with the mechanical valve, we performed replacement of the mechanical valve with the bovine pericardial valve in two cases. Case 1: The patient, at 13 years old, received open-heart surgery to correct infundibular stenosis. At 23 years of age, decortication and tricuspid valve replacement (TVR) with a phi 31 mm Björk-Shiley valve were performed due to constrictive pericarditis and tricuspid regurgitation developed after the initial operation. Thrombosis of the mechanical valve occurred after the TVR. Treatment with urokinase for the thrombolytic therapy failed to improve the valve opening. Finally 12 years after the TVR, replacement of the mechanical valve with a phi 27 mm Carpentier-Edwards bovine pericardial valve was performed. Case 2: The patient, at 21 years old, received open-heart surgery to close an atrial septal defect. At 40 years of age, mitral and tricuspid valve replacements were performed because regurgitation developed in both valves. The mitral and tricuspid valves were replaced with phi 27 mm and 31 mm St. Jude Medical valves, respectively. Thrombosis of the mechanical valve used for the TVR occurred 2 months after the replacement. The mechanical valve was replaced with a phi 27 mm Carpentier-Edwards bovine pericardial valve. In both cases, subjective symptoms improved and prosthetic valve complications did not occur after re-replacement with the bovine pericardial valve. These cases suggested that for TVR a bovine pericardial valve of sufficient size would be better to select than a mechanical valve.
Although cardiac dysfunction due to ischemia-reperfusion injury is considered to involve oxygen free radicals, the exact manner by which this oxidative stress affects the myocardium is not clear. As the occurrence of intracellular Ca2+ overload has been shown to play a critical role in the genesis of cellular damage due to ischemia-reperfusion, this study was undertaken to examine whether oxygen free radicals are involved in altering the sarcolemmal Ca2(+)-transport activities due to reperfusion injury. When isolated rat hearts were made globally ischemic for 30 min and then reperfused for 5 min, the Ca2(+)-pump and Na(+)-Ca2+ exchange activities were depressed in the purified sarcolemmal fraction; these alterations were prevented when a free radical scavenger enzymes (superoxide dismutase plus catalase) were added to the reperfusion medium. Both the Ca2(+)-pump and Na(+)-Ca2+ exchange activities in control heart sarcolemmal preparations were depressed by activated oxygen-generating systems containing xanthine plus xanthine oxidase and H2O2; these changes were prevented by the inclusion of superoxide dismutase and catalase in the incubation medium. These results support the view that oxidative stress during ischemia-reperfusion may contribute towards the occurrence of intracellular Ca2+ overload and subsequent cell damage by depressing the sarcolemmal mechanisms governing the efflux of Ca2+ from the cardiac cell.
Explore the source record for details and available documents.