Biomedical subjects

H Sugihara

Publications and source records attributed to H Sugihara.

At least 91 records · Page 5Linked to original sources

PubMed1999

Natural course of combined limb and palatal tremor caused by cerebellar-brain stem infarction.

After infarction of the left superior cerebellar peduncle and dentate nucleus, a patient developed tremor of the left upper limb beginning on the twelfth day followed by palatal tremor appearing 10 months after infarction. Surface electromyogram revealed a difference in the frequency of the tremor in the upper limb and soft palate. When the palatal tremor appeared, brain magnetic resonance T2-weighted images revealed high signal intensity of the contralateral, right inferior olivary nucleus. Subsequently, when the amplitude of palatal tremor became less severe, the high olivary signal intensity subsided whereas the hypertrophy of the nucleus remained. This patient provides useful information on the pathogenesis of skeletal and palatal tremor with brain stem or cerebellar lesions based on the differences in the onset and frequency of tremors and morphologic changes in the inferior olive.

Arm↗

PubMed1999

CD36 deficiency has little influence on the pathophysiology of hypertrophic cardiomyopathy.

CD36 is homologous with myocardial long-chain fatty acid (LCFA) binding protein and has been suggested to relate to myocardial fatty acid metabolism. Myocardial scintigraphy with iodine-123 15-(p-iodophenyl)-3-(R, S)-methylpentadecanoic acid (BMIPP) revealed an impairment in LCFA metabolism chiefly in the hypertrophic myocardium in hypertrophic cardiomyopathy (HCM). Recently, the incidence of CD36 deficiency has been reported to be high in HCM patients, and CD36 deficiency was proposed as an etiology of hereditary HCM. However, the pathophysiological effect of CD36 deficiency on HCM has not been fully investigated. We analysed the expression of CD36 antigens on both platelets and monocytes obtained from 82 patients with HCM using two-color flow cytometry. Among the study patients, seven patients (8.5%) demonstrated type II CD36 deficiency, whereas type I CD36 deficiency was not detected. Two of 23 patients (8.7%) with a family history of HCM and five of 59 patients (8.5%) without a family history of HCM showed type II CD36 deficiency respectively. Contrary to the previous report, three of 53 patients with asymmetric septal hypertrophy (ASH) (5.7%) and four of 29 patients without ASH (13.8%) showed CD36 deficiency. Moreover, clinical characteristics, scintigraphic findings, echocardiographic data, and hemodynamic findings disclosed no significant differences between the HCM patients showing normal CD36 expression and those with CD36 deficiency. The incidence of CD36 deficiency in HCM patients is not higher than in the general population. Therefore, CD36 deficiency is not a characteristic factor of HCM and has little influence on the pathyphysiology of HCM.

Adolescent↗

PubMed1999

Reverse redistribution of Tc-99m-tetrofosmin in patients with acute myocardial infarction.

We examined reverse redistribution (RR) of Tc-99m-tetrofosmin after a single injection in patients with acute myocardial infarction (AMI). Tc-99m-tetrofosmin myocardial SPECT was performed in 28 patients with AMI 10-14 days after the onset. Myocardial images were obtained 30 min and 180 min after the injection of 740 MBq of Tc-99m-tetrofosmin. The left ventricular wall was divided into 9 segments. Regional myocardial uptakes of Tc-99m-tetrofosmin were scored by 4-point scoring (0 = normal, 1 = mildly reduced, 2 = moderately reduced, and 3 = defect). RR was defined as an increase of more than 1 in the regional score in images at 180 min. RR of Tc-99m-tetrofosmin was observed in 17 of 20 patients with direct PTCA and 3 of 8 patients without reperfused therapy. RR was observed in 61 of all 252 segments. Coronary angiography performed 1 month later revealed that the infarct-related artery was patent in 19 of 20 patients (95%) with RR and in 3 of 8 patients (37.5%) with persistent defects (PD) (p < 0.05). In segment-by-segment analysis, the incidence of regional wall motion abnormality I month later was reduced in regions with RR compared to those with PD (p < 0.0001). In conclusion, RR of Tc-99m-tetrofosmin was frequently observed in patients with successful direct PTCA. As the segments with RR showed signs of preserved function 1 month later, this phenomenon may reflect a salvaged myocardium in AMI.

Adult↗

PubMed1999

Abnormal course, abnormal flow, and systolic compression of the septal perforator associated with impaired myocardial perfusion in hypertrophic cardiomyopathy.

BACKGROUND: The septal perforators in hypertrophic cardiomyopathy (HCM) show systolic compression. The compression is thought to be related to the malpositioned septal perforators, but its relation to the development of myocardial ischemia remains controversial. METHODS: We examined echocardiographically the blood flow and course of the major septal perforator in 142 consecutive patients with HCM; of these, 94 underwent coronary angiography to assess systolic compression of the septal perforators and 110 had thallium-201 scintigraphy. We then analyzed the relation of the findings in comparison with the results in 15 patients with valvular aortic stenosis (AS). RESULTS: The major septal perforator was visualized in 82 patients with HCM and in 8 patients with AS. The visualization did not depend on the pressure gradient between the left ventricle and aorta in the HCM patients, but did in the AS patients. In AS the perforator always showed a normal course near to, and convexly toward, the right ventricle. In 71 of the 82 HCM patients, the perforator was distant from the right-sided endocardium of the ventricular septum and often convex toward the left. The greater the leftward deviation, the higher was the grade of compression. In 48 of the 82 patients with HCM and in all of the 8 patients with AS who showed the flow signal, the septal perforator showed systolic retrograde flow; in the patients with HCM there was a significant correlation (r = 0.54, P <.05) between the peak velocity and the degree of leftward deviation. Furthermore, higher degrees of the leftward deviation and higher degrees of the systolic compression of the major perforator were each associated with a higher incidence of exercise-induced defect of thallium-201. CONCLUSION: The echocardiographic, angiographic, and scintigraphic findings in HCM may be closely related to one another. We speculate that the series of abnormalities is initiated by a high intramural pressure and impedance on the septal perforators due to their deviation toward the left.

Adult↗

PubMed1999

Primary structure and biological activity of snake venom lectin (APL) from Agkistrodon p. piscivorus (Eastern cottonmouth).

A lectin (APL) was purified from the venom of Agkistrodon piscivorus piscivorus (Eastern cottonmouth moccasin). APL is a disulfide-linked, homodimeric protein consisting of identical monomers of molecular weight 16,200. Native rabbit and human erythrocytes were agglutinated by APL and the activity was found to be calcium-dependent. Galactose, lactose, rhamnose and EGTA strongly inhibited the hemagglutination activity of APL. The complete amino acid sequence determined by Edman sequencing of the S-pyridylethylated derivative and its peptides derived from enzymatic digestion indicate the structure of APL to be highly homologous with lectins and the platelet glycoprotein Ib (GPIb)-binding proteins isolated from other snake venoms. These results suggest that APL belongs to the C-type beta-galactoside binding lectin family which possess structural similarities with the C-terminal carbohydrate-recognition domain (CRD) of animal membrane lectins.

Agkistrodon↗

PubMed1999

Skin manifestations of a patient with mitochondrial encephalomyopathy with lactic acidosis and strokelike episodes (MELAS syndrome).

Skin abnormalities in a patient with newly diagnosed MELAS syndrome are reported. He presented with scaly, pruritic, diffuse erythema with reticular pigmentation on his entire body. Moderate hypertrichosis was also noted on the lower extremities. Thickened arrector muscles with longitudinal and cross sections were seen in the dermis. Analysis of mitochondrial DNA in a biopsy specimen from the biceps brachii disclosed the presence of an A-to-G point mutation at nucleotide pair 3243. Electron microscopy revealed marked increase in the number of morphologically abnormal mitochondria in the arrector muscles of the involved skin. This is the first report of a MELAS syndrome patient with skin manifestations and evidence of morphologically abnormal mitochondria.

Adult↗

PubMed1999

Brain dysfunction associated with an induction of nitric oxide synthase following an intracerebral injection of lipopolysaccharide in rats.

We investigated the pathophysiological role of nitric oxide synthesized by inducible nitric oxide synthase in the brain, by injecting lipopolysaccharide directly into the rat cerebral cortex/hippocampus. The levels of nitric oxide metabolites, nitrite and nitrate, began to increase in a dose-dependent manner with a 3-h lag, and reached approximately seven-fold the basal levels 8 h after the direct injection of lipopolysaccharide (5 microg). The lipopolysaccharide-induced increase in nitrite and nitrate levels was inhibited by treatment with the specific inducible nitric oxide synthase inhibitor aminoguanidine. The protein synthesis inhibitor cycloheximide delayed the onset of the increase in nitric oxide metabolite levels, and reduced the peak levels. Lipopolysaccharide increased Ca2+-independent, but not Ca2+-dependent, nitric oxide synthase activity in the brain. Intense nicotinamide adenine dinucleotide phosphate-diaphorase activity was observed in round cells in the vicinity of the site of injection of lipopolysaccharide 8 h after the injection. Neuronal death was observed seven days after the injection of lipopolysaccharide. Spatial memory, as assessed by performance in a water maze task and spontaneous alternation behavior in a Y-maze, was significantly impaired in rats which had had previous bilateral injections of lipopolysaccharide into the hippocampus. The lipopolysaccharide-induced neuronal death and spatial memory impairments were prevented by aminoguanidine. These results suggest that direct injection of lipopolysaccharide into the brain causes an induction of inducible nitric oxide synthase in vivo. Furthermore, it is suggested that nitric oxide produced by inducible nitric oxide synthase is responsible for the lipopolysaccharide-induced brain dysfunction.

Analysis of Variance↗

PubMed1999

Histopathological analysis of apoptosis, and expression of p53, bcl-2, bax, and Ki-67 in laryngeal squamous cell carcinomas and dysplasia.

The growth of neoplasia is determined by the proliferation and loss of cells. The purpose of this study is to determine the frequency of apoptosis in laryngeal carcinomas and to examine its relationship to the pathological parameters, including ki-67 expression, and to expression of p53, bcl-2, and bax protein. The materials are 67 cases of laryngeal squamous cell carcinomas (SCCs) and 22 cases of squamous dysplasia using biopsy and surgery specimens. Apoptotic cells were determined by the modified TUNEL method. Expressions of p53, bcl-2, and bax, i.e. apoptosis-related genes, and ki-67, a proliferation marker, were immunohistochemically examined. The relationships between apoptosis and the clinicopathological findings were studied. The stage of the carcinoma was not related to the apoptotic index. The expression of p53 was frequently detectable in the advanced carcinomas with T3, T4 and N-positive. The apoptotic index was not significantly related to recurrence, metastasis or histological differentiation. Apoptosis occurred frequently in the cornified areas of well differentiated SCCs. The expressions of ki-67 observed in the poorly differentiated SCCs was significantly higher than that observed in the well differentiated SCCs (P< 0.01). The apoptotic index increased after irradiation in the carcinoma. No relationship was found between apoptotic index, ki-67 index, and expression of p53, bcl-2 and bax. The apoptotic index obtained form the SCCs was significantly higher than that obtained form squamous dysplasias (P < 0.05). Various apoptosis-related findings including p53 expression were observed in the advanced type of laryngeal SCCs, and apoptosis of the carcinoma was suggested to be controlled by complicated factors including bcl-2.

Adult↗

PubMed1999

Proliferation and differentiation of rat dorsal prostatic epithelial cells in collagen gel matrix culture, focusing upon effects of adipocytes.

BACKGROUND: Prostatic epithelial cells organize functional acinus structures under epithelial extracellular matrix and epithelial-stromal cell interactions. Recently, the adipose tissue, which surrounds and even exists within the prostate, has been suggested to affect the differentiation and proliferation of some cell types. Therefore, tissue fragments, which consist mainly of epithelial and fibromuscular stromal cells, were cultured in three-dimensional collagen gel matrix culture with adipocytes. METHODS: Tissue fragments of rat dorsal prostate, including both epithelial and fibromuscular stromal components, were cultured in collagen gel with or without adipocytes. Epithelial cell differentiation was evaluated with the reconstruction of acinus-like structures and with immunohistochemistry of rat dorsal prostate-specific proteins, dorsal protein-1 and probasin. The proliferation was examined by uridine uptake. RESULTS: Under coculture of the fragments and adipocytes, epithelial cells reconstructed more differentiated acinus-like structures surrounded by fibromuscular stromal cells than tissue fragment culture without adipocytes. Dorsal protein-1 and probasin expressions of epithelial cells in this coculture system were the same as in rat prostate in vivo. In the coculture, epithelial cells had a higher proliferation activity. CONCLUSION: These results indicate that adipocytes promote proliferation and differentiation of prostatic epithelial cells. Our new culture model with adipocytes suggests the importance of cell-cell interactions, including those of epithelial cells and adipocytes.

Adipocytes↗

PubMed1999

Expression of fibroblast growth factor-2 transcripts in the healing of acetic acid-induced gastric ulcers.

Basic fibroblast growth factor-2 (FGF-2) has an important role in angiogenesis, and has been demonstrated to promote ulcer healing. However, the actual part played by FGF-2 in the process of ulcer healing is not well understood. In this study, we investigated expression of FGF-2 transcripts at each stage of gastric ulcer healing, using an acetic acid model in rats. We made ulcers in the rat stomach by direct application of acetic acid, and 3 days and 1, 2, 3, 4, 8 weeks after treatment, we examined expression of FGF-2 transcripts by in situ hybridization. On day 3, FGF-2 transcripts were detected in mononuclear cells infiltrating the submucosal layer around the ulcer. After 1 and 2 weeks, expression of FGF-2 transcripts was prominent in spindle-shaped mesenchymal cells and endothelial cells, which proliferated in the ulcerative region. Some of the spindle-shaped cells which expressed FGF-2 transcripts also showed immunoreactivity for alpha-smooth muscle actin. After 3 and 4 weeks, FGF-2 expression was seen mainly in endothelial cells of vessels. These results suggest that different cells produce FGF-2 during the process of gastric ulcer healing, and some of the spindle-shaped cells expressing FGF-2 transcripts in the early phase are myofibroblasts.

Acetates↗

PubMed1999

Reduced growth hormone receptor messenger ribonucleic acid in an aged man with chronic malnutrition and growth hormone resistance.

A severely malnourished 87-yr-old man presented with hypoglycemia. Serum GH levels were elevated, and serum levels of insulin-like growth factor I (IGF-I), IGF-binding protein-3, and GH-binding protein were extremely reduced. The patient's GH was biologically active. Administration of GH for 4 consecutive days resulted in a slight increment in serum IGF-I levels, but no elevation of serum IGF-binding protein-3. The expression of GH receptor messenger ribonucleic acid in the liver was greatly reduced. An autopsy revealed a Rathke's cleft cyst confined to the sella turcica. Immunohistochemical studies for GH showed that there was nothing to suggest a tumor overproducing GH. In addition, TSH levels were elevated in the presence of normal thyroid hormone levels, and there was a cluster of cells showing strong immunohistochemical staining for the TSH beta-subunit in the pituitary. In this patient, the decreased expression of GH receptor messenger ribonucleic acid in the liver may have been responsible for the GH resistance, which was probably caused by malnutrition.

Aged↗

PubMed1999

Proliferation and differentiation of unilocular fat cells in the bone marrow.

Fat cells contribute not only to systemic lipid metabolism, but also to osteogenesis and hemopoiesis in the bone marrow. The present study represents the first attempt to culture mature unilocular fat cells of the bone marrow. Two methods devised in our laboratory were employed: one is the "ceiling culture method" that utilizes the floating property of the cells; the other, a three-dimensional collagen gel matrix culture that captures unilocular fat cells in the gel matrix. Using these methods, the proliferation of unilocular fat cells from the bovine metacarpal bone marrow was demonstrated. First, we confirmed the proliferative ability of unilocular fat cells derived from the bone marrow, using autoradiography to study 3H-thymidine incorporation into the nuclei. The unilocular fat cells de-differentiated into fibroblast-like fat cells and then proceeded to proliferate. When they underwent a contact inhibition of growth, re-differentiation from fibroblast-like fat cells into unilocular fat cells occurred at a high rate. A specific enzymatic marker of the fat cell, alpha-glycerophosphate dehydrogenase activity related to lipogenesis, was then demonstrated in the cultured fat cells. We examined the functional reactivity of the fat cells by treatment with insulin and cyclic-AMP, and both lipogenesis and lipolysis were also confirmed in them. We concluded that unilocular fat cells from the bone marrow de-differentiated, proliferated and re-differentiated in culture. The present results may help to clarify the various functions of fat cells in the bone marrow.

Adipocytes↗

PubMed1999

Improved survival of idiopathic dilated cardiomyopathy in the 1990s.

To analyze the recent change in the long-term survival of patients with dilated cardiomyopathy (DCM), the present study comprised consecutive 111 patients with ejection fraction <50% and left ventricular end-diastolic diameter >58 mm. who were admitted to hospital from January 1983 to December 1994. The patients were divided into 2 groups: group A who were diagnosed before 1989 and group B diagnosed after 1990. Basic characteristics at diagnosis, including age, NYHA functional class, left ventricular end-diastolic diameter and ejection fraction, were similar between these 2 groups. Calculated survival rate at 5 years was 90.0% in group B in contrast to 62.3% in group A. Event-free survival also improved in group B. In group B, beta-blockers and angiotensin converting enzyme inhibitors were more frequently used than in group A (p<0.0001) whereas digitalis and other positive inotropic agents were significantly less used. Left ventricular ejection fraction was significantly improved during the follow-up period in patients treated with beta-blockers compared with those not treated with beta-blockers. These data indicate a significant improvement in the survival of patients with dilated cardiomyopathy after 1990, which may be explained by the change of medical treatment, especially the use of beta-blockers.

Adrenergic beta-Antagonists↗

PubMed1999

Overexpression of fibroblast growth factor receptor 3 in a human thyroid carcinoma cell line results in overgrowth of the confluent cultures.

Recent reports indicate that a gain-of-function mutation in fibroblast growth factor receptor 3 (FGFR-3) inhibits cell growth in the cartilaginous growth plates. These results suggest that FGFR-3 may be the receptor transducing growth inhibitory signals. Using reverse transcription-PCR we examined seven papillary thyroid carcinomas to determine FGFR-3 expression. Six out of the seven papillary carcinomas expressed FGFR-3. To clarify the role of FGFR-3 in thyroid carcinoma, FGFR-3 was overexpressed in an established human papillary thyroid carcinoma cell line. High levels of FGFR-3 protein were identified in cells stably transfected with the vector containing FGFR-3 cDNA. The specific binding of 125I-FGF-2 of these cells was threefold higher than that of control cells. Growth rates of cells overexpressing FGFR-3 were similar to those of control cells. However, cells overexpressing FGFR-3 continued to grow beyond the density at which control cells stopped proliferating. These results suggest that FGFR-3 in thyroid carcinoma is not involved strongly in the cell proliferation mechanism but may contribute to the malignant extension of some of the carcinomas by modifying cell contact signaling.

Carcinoma, Papillary↗

PubMed1999

Relationship between coronary blood flow velocity waveform and transmural distribution of myocardial blood flow in coronary artery.

It is important to know the transmural distribution of myocardial blood flow in assessing the severity of ischemia in coronary heart disease. We analyzed the relation between phasic waveform of epicardial coronary flow velocity with a Doppler flow probe in the left anterior descending artery in dogs and regional myocardial blood flow using a colored microsphere technique. Time-velocity integral in an average of 5 cardiac cycles was measured as an index of coronary blood flow during diastole (TVId) and systole (TVIs). The diastolic fraction of coronary blood flow (%DF) was defined as TVId/(TVId + TVIs). Myocardial specimens were divided into inner (subendocardial), middle, and outer (subepicardial) layers, and the inner layer to outer layer myocardial blood flow ratio (endo/epi ratio) was used as an index of transmural distribution of myocardial perfusion. The mean endo/epi ratio and the mean %DF decreased as the pressure gradient increased. There was a moderate but significant correlation (r = 0.57) between the endo/epi ratio and the %DF. In conclusion, analysis of the phasic pattern of coronary blood flow velocity provides some information about the transmural distribution of blood flow in the myocardium. The %DF may be a useful index for evaluating subendocardial ischemia.

Animals↗

PubMed1999

The effect of an Aspergillus fumigatus derived elastolytic proteinase on human neutrophils.

The effect of elastolytic proteinase on quantitative nitroblue tetrazolium (NBT) dye reduction and chemotaxis of human neutrophil was examined. Elastolytic proteinase is derived from Aspergillus fumigatus 9409. NBT dye reduction was inhibited significantly by 133microEg/ml of elastolytic proteinase (p<0.05). Chemotaxis was also inhibited significantly by 400microEg/ml of the enzyme, compared to the control group (p<0.05). These findings suggest that elastolytic proteinase, depending on its concentration, acts as an inhibitory agent to both NBT dye reduction and chemotaxis activities in the human neutrophil. The findings that this enzyme suppressed neutrophil function in A. fumigatus infection is of importance, because it is now suspected that the enzyme has the potential to cause infection.

Aspergillus fumigatus↗

PubMed1999

[The role of virulence factor of elastolytic proteinase from Aspergillus fumigatus].

The role of virulence factor of elastolytic proteinase produced by Aspergillus fumigatus was investigated in mice immunocompromised with cyclophosphamide (CY) to block neutrophil and lymphocyte functions or with carrageenan (CA) to block the phagocytic activity of macrophages. These mice were infected through inhalation with the spores of elastolytic proteinase producing or nonproducing strains of A. fumigatus, and then were observed daily for 15 days or until death. Compared to CY-immunocompromised mice treated with the spores of proteinase nonproducing strains, CY-immunocompromised mice treated with the spores of proteinase producing strains had a significantly shorter survival rate. Furthermore, when treated with the spores of proteinase producing strains, CA-immunocompromised mice survived significantly longer than did CY-immunocompromised mice. Assessment of the effect of elastolytic proteinase on rat lung showed that this enzyme induced hemorrhage of the lung, alveolar septal edema and alveolar hypertrophy due to blood neutrophil infiltration. Neither fusion nor denaturation of the elastic fiber was observed, however. These studies have suggested that when infected with A. fumigatus, a severe lesion in bronchioli or alveoli is induced by the proteinase producing strains, and that these strains are more virulent than the proteinase nonproducing strains.

Animals↗

PubMed1999

[The usefulness of 123I-BMIPP myocardial SPECT in diagnosis for silent myocardial ischemia induced by vasospasm].

This study was designed to evaluate the clinical usefulness of 123I-BMIPP myocardial SPECT in patients with silent myocardial ischemia induced by vasospasm. Ultrasonic echocardiography (UCG), Holter electrocardiogram recording (Holter ECG), exercise 201Tl myocardial SPECT (EX-Tl) and rest 123I-BMIPP myocardial SPECT (BMIPP) were performed in 8 patients with asymptomatic vasospasm without history of myocardial infarction. The sensitivity of each modality in detecting coronary artery spasm was 37.5% (3 of 8 cases) for UCG, 37.5% (3 of 8 cases) in Holter ECG, 25.0% (2 of 8 cases) in Ex-Tl, 62.5% (5 of 8 cases) on initial BMIPP images and 75.0% (6 of 8 cases) on delayed BMIPP images. Severity of regional left ventricular wall motion abnormality in UCG correlated with the severity of regionally decreased tracer uptake in BMIPP. The washout rate of BMIPP was 18.7 +/- 2.4 in normal controls, 32.4 +/- 5.9 in asymptomatic vasospasm, and 38.2 +/- 4.0 in asymptomatic vasospasm with abnormal left ventricular wall motion. It was suggested that 123I-BMIPP myocardial SPECT might be useful for assessing asymptomatic vasospasm.

Adult↗