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Biomedical subjects

R Hashimoto

Publications and source records attributed to R Hashimoto.

At least 91 records · Page 5Linked to original sources

Utilization behavior after right thalamic infarction.

We report a patient who showed exaggerated responses to external cues (utilization behavior), motor impersistence, and a right-hand-predominant instinctive grasp reaction after right thalamic infarction. High-resolution computed tomography with stereotaxic lesion localization revealed almost complete destruction of the ventroanterior nucleus and intralaminar nuclei of the right thalamus; the dorsomedial nucleus was only partially involved. Single photon emission computed tomography revealed hypoperfusion in the right thalamus and over the entire right cerebral cortex with some prominence in the frontal area. From these observations, we believe that the utilization behavior in our case was caused by the disturbance in maintaining cortical tone of the right hemisphere as well as by the dysfunction of the right frontal lobe, both secondary to the damage to the right ventroanterior nucleus and intralaminar nuclei.

Aged↗

Relationship between associations of NOR and chromosomal anomalies in the abnormal embryos of nonobese diabetic and STZ-diabetic mouse.

Associations of nucleolar organizing regions (NORs) in the postimplantation stage embryos of nonobese diabetic (NOD) mice, and diabetic ICR mice induced by streptozotocin (ST), were studied to investigate the possible cause of the numerical anomalies of the chromosomes in their abnormal embryos. The incidence of NOR associations in abnormal embryos from diabetic NOD (NOD-DM) and STZ-diabetic mice was 11.7 and 7.7%, respectively. This incidence was significantly higher than that (1.2%, p < 0.05) of normal embryos from ICR mice which were used as control. From the results analyzed cytogenetically it was suggested that the higher incidence of chromosomal numerical anomalies in the embryos from NOD-DM and STZ-diabetic mice were caused by the chromosomal nondisjunction induced by associations of NORs. Furthermore, it was suggested that NOD-DM embryos have a tendency to increase the associations of NOR in a diabetic condition together with other factors such as autoimmune disease, however a diabetic condition alone induced chromosomal anomalies. Regarding relationships between the incidence of associations of NOR and the types of malformed embryos, it was also clear that all of the abnormal embryos from NOD-DM and STZ-diabetic mice had a high incidence of associations of NOR, and that the incidence was not related to the types of congenital anomalies. Furthermore, in the mal-developed tissue of embryos from STZ-diabetic mice, many chromosomal anomalies were found (26.6%), and the incidence was similar to that of whole embryos (22.6%).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Serum N-acetyl-beta-D-glucosaminidase activity in predicting the development of hypertension.

We conducted a prospective study in residents of a small farming community in southwestern Japan to determine whether elevated serum N-acetyl-beta-D-glucosaminidase (NAG) activity would predict future hypertension. The 505 normotensive subjects (blood pressure, < 140/90 mm Hg; mean age, 52 +/- 12 years) were reexamined after 7 years; 111 (22%) had become hypertensive (defined as blood pressure > or = 140/90 mm Hg and/or taking antihypertensive medication at follow-up). After adjustment for age and sex, the development of hypertension was significantly related to body mass index (P < .002), the sum of skinfolds (P < .001), baseline blood pressure (P < .0001), serum cholesterol (P < .01), serum uric acid level (P < .0001), and serum NAG activity (P < .005). Elevated NAG activity showed an independent relationship to future hypertension (P < .005) after adjustments for age, sex, baseline blood pressure (systolic, diastolic, or mean), uric acid level, and the sum of skinfolds. Therefore, elevated serum NAG activity was an effective indicator of future hypertension, and it might therefore be related to functional and/or structural changes in the cardiovascular system.

Acetylglucosaminidase↗

Isolation and characterization of the IS3-like element from Thermus aquaticus.

We have cloned and characterized a genetic element (1187 bp) that is responsible for the induction of thermotolerance as well as ompC expression in E. coli. This element (ISLtaq1) was isolated from Thermus aquaticus. DNA and protein data bases were searched with this element (ISLtaq1), which suggested it to be very similar to IS150 belonging to the IS3 family. ORF1, found on ISLtaq1, which encodes 100 amino acids (aa), had a DNA-binding motif: a helix-turn-helix and a leucine zipper. In fact, when the ORF1 protein was overproduced in E. coli, thermotolerance as well as ompC expression was induced.

Adaptation, Biological↗

Association of hyperinsulinemia and serum free fatty acids with serum high density lipoprotein-cholesterol.

A total of 155 Japanese subjects (79 men and 76 women) who were classified as having normal or borderline glucose tolerance, according to the criteria for the 50-g oral glucose tolerance test (GTT) of the Japanese Diabetes Society, were analyzed for factors related to serum high density lipoprotein (HDL)-cholesterol concentration, especially the responses of insulin and free fatty acid (FFA) after a glucose challenge. In men, significant negative univariate correlations were observed with body mass index (P < 0.01), the summed values of triceps and subscapular skin-folds (P < 0.01), serum insulin concentration at all time intervals, and serum FFA at 30 and 60 min of GTT. Serum insulin at 60, 120, and 180 min, sum insulin, and FFA at 30 and 60 min of GTT were significantly related to serum HDL-cholesterol after adjustment for body mass index and triglyceride concentration. Multiple linear regression analysis with the step-forward method showed that sum insulin (P < 0.01), FFA at 60 min of GTT (P < 0.001), and alcohol consumption (P < 0.01) were independently related to serum HDL-cholesterol concentration. Only the triglyceride concentration was inversely correlated (P < 0.05) with HDL-cholesterol concentration in women. These data indicate that both insulin and FFA concentration, as markers of insulin resistance, apparently influence on HDL kinetics in men, but not in women. The lack of this association in women was appeared to related to the degree of obesity.

Adult↗

[Postoperative choreoathetosis in a case of tetralogy of Fallot].

We presented a case of severe postoperative choreoathetosis which occurred in a 3-year-old boy with tetralogy of Fallot early postoperatively but almost completely recovered within two years after the operation. Because of the large coronary arterial branch on the right ventricular outflow, a small outflow incision and deep hypothermia (lowest rectal temperature was 13 degrees C) and short duration of circulatory arrest (8 minutes) were adopted. Postoperative course was uneventful till the onset of choreoathetosis on the fifth postoperative day. His symptoms and signs of choreoathetosis, oral-facial dyskinesias, hypotonia, affective changes and also pseudobulbar signs were becoming serious during the first week from the onset, but afterwards his condition started getting better gradually every week, and every month. Now, 20 months after the operation, he is almost completely recovered except for small and slow involuntary movements. Though investiations including CT, MRI and EEG were all almost normal, regional nonspecific low area of the frontal lobe and cerebellum was detected by SPECT (single photon emission computed tomography) on the 32nd and 94th postoperative days, respectively.

Athetosis↗

[Effects of preserving mitral apparatus on left ventricular systolic function and geometry in mitral valve replacement].

We investigated the left ventricular (LV) systolic function and geometry in mitral valve replacement (MVR) with and without preservation of mitral apparatus. Five patients had conventional MVR without mitral annulus papillary muscle continuity (group C) and five patients had MVR with preservation of the continuity (group P). LV cineangiograms were assessed before and one month after surgery. LV volume was calculated by the method of Kennedy. Long axis dimension is defined as the distance between the apex and the center of mitral orifice in right anterior oblique projection. Short axis dimension is defined as the cross-sectional dimension at the middle point of the long axis. Paired Student's t tests were employed to compare the preoperative and postoperative data. LV ejection fraction decreased significantly from 69.4 +/- 9.5 to 51.8 +/- 10.5% in group C (p < 0.05) and did not change significantly in group P (from 51.6 +/- 19.9 to 56.8 +/- 12.9%). Fractional shortening of the long axis increased significantly from 15.0 +/- 11.8 to 21.2 +/- 14.0% in group P (p < 0.02) and did not change significantly in group C (from 16.5 +/- 8.6 to 13.1 +/- 3.3%). Ratio of LV end-systolic long axis to short axis dimension increased significantly from 1.76 +/- 0.31 to 2.12 +/- 0.21 in group C (p < 0.05) and did not change significantly in group P (from 1.90 +/- 0.22 to 1.95 +/- 0.22). We conclude that the ratio of systolic long to short axis increases, i.e., systolic LV shape changes to become longer and slender, and ejection fraction decreases after surgery in MVR without preservation of mitral apparatus. Conversely, preserving the mitral apparatus in MVR results in no significant change in systolic LV function and geometry, because of preserving fractional shortening of long axis.

Aged↗

Ontogeny of alpha-crystallin subunits in the lens of human and rat embryos.

The distribution of alpha A- and alpha B-crystallin in the developing lens of human (Carnegie stages 13 to 23) and rat embryos (embryonic days E11 to 18) was examined immunohistochemically. In a human embryo at stage 13, the lens placode was already immunoreactive to alpha B-crystallin, but not to alpha A-crystallin. At stage 15, the lens vesicle was intensely immunoreactive both to alpha A- and alpha B-crystallin. From stages 16 to 23, the lens epithelial cells and fiber cells were immunoreactive to alpha A- and alpha B-crystallin. In rat embryos, alpha A-crystallin appeared in the lens pit at E12, and alpha B-crystallin appeared in the elongating lens fiber cells at E14. From E15 to E18, the lens epithelial cells and fiber cells were immunoreactive to alpha A-crystallin. The lens fiber cells were also immunoreactive to alpha B-crystallin, but the epithelial cells were not. These findings suggest that alpha B-crystallin appears earlier than alpha A-crystallin in the human lens, but at a later period than alpha A-crystallin in the rat lens. alpha B-Crystallin was not detected in the epithelial cells of the rat lens, but was persistently present in the epithelial cells of the human lens.

Animals↗

The effect of exercise on plasma biopterin levels.

The plasma total biopterin and tetrahydrobiopterin levels of 29 normal volunteers were measured before and after exercise by ergometer, and those of 10 were also measured until 24 h after exercise. An increase of plasma total biopterin and tetrahydrobiopterin was observed only after strong exercise, which exhausted the subjects, the ratio of tetrahydrobiopterin to total biopterin not differing before and after exercise. The increase of plasma biopterins disappeared 2 h after exercise. The mechanism of the increase of plasma biopterins was thought to be different from that of patients with affective disorders.

Adult↗

Changes in plasma tetrahydrobiopterin levels of depressives in depressive and remission phases: reconfirmed by measurement with an internal standard.

Plasma total biopterin and tetrahydrobiopterin levels of 10 normal controls and 10 patients with monopolar depression were measured with and without internal standard. The levels did not differ between the two methods. A significant increase of total biopterin levels and the lower ratio of tetrahydrobiopterin to total biopterin in the depressive phase were observed in the plasma of patients with depression compared to normal controls, and these changes in plasma biopterin tended to normalize in the remission phase.

Adult↗

Microinjection of LHRH and its antagonistic analog into the medial preoptic area does not affect pulsatile secretion of LH in ovariectomized rats.

To gain a better understanding of the existence of an ultra-short feedback mechanism controlling LHRH secretion in the medial preoptic area (MPO), we examined the effects of microinjections of LHRH or the LHRH antagonist [D-pGlu1, D-Phe2, D-Try3,6] into the MPO on pulsatile secretion of LH in ovariectomized rats and on the surge of LH secretion in proestrous rats. Neither the injection of 10 ng LHRH nor 100 ng its antagonist into the MPO had any effect on pulse frequency or the mean LH concentration in ovariectomized rats. The injection of 100 ng LHRH antagonist or 10 ng LHRH delayed or advanced, respectively, the LH surge in proestrous rats. Taking these results together with our previous report, the present study indicates that 1) endogenous LHRH in the MPO is involved in the ultra-short feedback regulation of LHRH release and 2) the ultra-short positive feedback mechanism in the MPO acts at the time of the proestrous LH surge but not under a hormonal milieu as in ovariectomized rats.

Animals↗

Fungal metabolites. Part 14. Novel potent immunosuppressants, mycestericins, produced by Mycelia sterilia.

Mycestericins A, B, C, D and E were isolated from the culture broth of Mycelia sterilia ATCC 20349 along with thermozymocidin (= myriocin). Their structures were elucidated on the basis of spectroscopic studies and chemical evidence. The acetate of mycestericin C was identical with the acetate of 6,7-dihydromyriocin. Mycestericins suppressed the proliferation of lymphocytes in the mouse allogeneic mixed lymphocyte reaction, with a potency similar to that of myriocin.

Animals↗

[Intrabronchial neurilemmoma: a case report].

A 62-year-old woman who was pointed out abnormal shadow at left middle lung field in chest X-ray was followed up as a hamartoma from 1989. In this period, the tumor was growing up in chest X-ray and occupying the left segmental bronchus (B3) in bronchofiberscopic study. It was suspected neurilemmoma by the final biopsy examination. Left upper lobectomy was performed and pathohistological diagnosis was typical neurilemmoma that consist of Antoni type A and Antoni type B. Intrapulmonary or intrabronchial neurilemmoma is rare and only 20 cases have been reported in the Japanese literature.

Bronchial Neoplasms↗

Ultrastructure of the developing stomach in human embryos.

Ultrastructural development of the stomach was studied by light, scanning electron and transmission electron microscopy, using 19 human embryos at Carnegie stages from 14 to 23 (6.8-28.0 mm in crown-rump length, 5 to 8 weeks of gestation). The precise time of appearance of differentiated characteristic structures was examined electron microscopically. The first gastric pit, with radially arranged epithelial cells beneath which the basement membrane bulged into the mesenchyme, was observed on the lesser curvature at stage 22. Although the mesenchymal condensation which would develop into the inner circular muscle layer appeared at stage 18 onward, cytoplasmic myofibrils were not observed until stage 22. Nerve fibers were first observed at stage 16, and at later stages they gathered into bundles to form a nerve plexus external to the developing inner circular muscle layer. On the basis of accurate timing of the appearance and the mode of development of these structures, possible relations between developing gastric layers were discussed. Histocytochemically, glycogen or other carbohydrates were demonstrated in the cytoplasm of the gastric epithelium throughout the stages examined. These carbohydrates were localized mainly in vacuole-like spaces in the basal part of the epithelial cells. This subcellular localization, and the amount of carbohydrate, did not change significantly during the observed embryonic period. In the serosa, carbohydrates were not detected at stages 14 and 15, but observed consistently within the vacuoles in the cytoplasm from stage 17 onward. No other layer of the embryonic stomach had detectable carbohydrates.(ABSTRACT TRUNCATED AT 250 WORDS)

Embryo, Mammalian↗