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Biomedical subjects

S Imai

Publications and source records attributed to S Imai.

At least 199 records · Page 11Linked to original sources
PubMed1996

Comparative study of rumen ciliates in buffalo, cattle and sheep in Egypt.

Rumen ciliates species and composition of the sheep, Friesian-cattle and water buffaloes in Egypt were surveyed. As a result, 7 genera with 18 species and 6 formae in sheep, 10 genera with 28 species and 11 formae in cattle and 12 genera with 29 species and 7 formae in water buffaloes were detected. Twenty-two species were common in both cattle and buffaloes, while 12 species in sheep were common with the other ruminants. Entodinium spp., such as E. simplex, E. nanellum and E. exigum, appeared most frequently in every host. In general, Egyptian domestic ruminants had the rumen ciliate composition similar to that of domestic ruminants in temperate zone, though the water buffaloes had several tropical species such as Entodinium longinucleatum forma spinonucleatum. The ciliate density was estimated as 10(5)/ml in every host species.

Animals↗
PubMed1996

Ciliate protozoa in the forestomach of the dromedary camel, (Camelus dromedarius), in Egypt, with description of a new species.

The composition of ciliates obtained from the forestomachs of eleven dromedary (one-humped) camels in Egypt was examined. As a result, eight genera containing 24 species with 11 forms were identified. Of them, one species was concluded to be new, then described as Dasytricha kabanii n. sp. This new species was clearly distinguished from D. ruminantium, the other species of the genus, by its lack of somatic cilia on the posterior one-fifth of the body surface. Entodinium nanellum and Epidinium ecaudatum f. caudatum were found in all camels examined. Although the percentage composition of respective species varied with the individual camel, the rate of Entodinium spp. was high in general. Total ciliate density in forestomach fluid was 1.9 x 10(5)/ml on average. Ciliate composition in Egyptian camels was similar to that in Bactrian camels, Camelus bactrianus, in China reported previously. However, more Entodinium species were detected from Egyptian camels than from Bactrian camels.

Animals↗
PubMed1996

Relation between depressed cardiac response to exercise and autonomic nervous activity in mildly symptomatic patients with idiopathic dilated cardiomyopathy.

We investigated whether the depressed cardiac response to adrenergic stimulation is accompanied with impaired autonomic function in mildly symptomatic patients with idiopathic dilated cardiomyopathy (DCM). Twenty-seven patients with DCM (New York Heart Association class I or II) and 7 normal control subjects underwent exercise radionuclide ventriculography and 24-h ambulatory ECG. The following frequency components of heart rate variability were calculated: the areas under the low (low frequency component [LF], 0.04 to 0.15 Hz), high (high frequency component [HF], 0.15 to 0.40 Hz), and total frequency portions of the spectrum. HF and HF% (the ratio of HF to total power) were calculated as indexes of specific vagal influences, and LF% (the ratio of LF to total power) and the ratio of LF to HF were of sympathetic tone. The left ventricular ejection fraction (LVEF) increased by more than 5% in all normal control subjects during exercise, whereas 17 (63%) of patients failed to show more than a 5% increase in LVEF. The profile of the mean hourly HF% and LF/HF showed circadian variations in normal control subjects but not in patients. The HF and HF% during sleep were significantly lower and the LF/HF during sleep was higher in patients than in normal control subjects. In patients, the LVEF during exercise minus LVEF at rest was significantly correlated with HF, LF%, and LF/HF during sleep, and with the ratios of the mean values during early morning to the mean daytime values for those spectral indexes. Our results demonstrated that mildly symptomatic patients with DCM showed an attenuated cardiac response to exercise and altered autonomic function, and their close relationship, suggesting that autonomic nervous activity contributes to cardiac desensitization in DCM.

Adrenergic Fibers↗
PubMed1996

Neuropeptides and the puzzle of bone remodeling. State of the art.

Bone metabolism is dependent on cells of the osteoblast and osteoclast lineage. These cells play a major role in the synthesis and degradation of osteoid and in its mineralization and demineralization. Bone cells are under the influence of various systemic and local auto/paracrine factors. One further regulatory element that can play both a sensory/ afferent and a regulatory/efferent role, consists of neuropeptide-containing nerves. In particular, the calcitonin gene-related peptide (CGRP) and vasoactive intestinal peptide (VIP) have been implicated; their distribution in bone and their molecular biology are discussed in some detail. Bone neuropeptides can function as direct bone cell regulators, with additional amplifying indirect effects mediated by vascular endothelial cells, monocyte/macrophages and mast cells and their mediators. Recent experimental and clinical work has implicated bone nerves in processes varying from normal remodelling to fracture healing and non-union. Apart from systemic endocrine influences on bone stock and osteoclast/ osteoblast coupling (activation-resorption-formation cycle) mediated by local auto/paracrine factors, bone nerves/neuropeptides may explain why various inputs/outputs are transformed in a meaningful way to altered mass and quality of bone.

Bone Remodeling↗
PubMed1996

Measurement of visco-elastic properties of muscles around the ankle during standing.

The aim of this study was to determine elastic and viscous coefficients of muscles around the ankle during standing, and to investigate whether these coefficients depended on the balance task. By means of a servo-controlled platform, angle disturbances of the ankle were imposed upon a standing subject under three conditions: (a) standing on both legs with eyes open, (b) standing on both legs with eyes closed and (c) standing on one leg with eyes open. Visco-elastic properties of muscles around the right ankle of seven subjects were estimated using data for ankle moment and angle. Mean elastic coefficients changed from 151 to 220 Nm/rad and mean viscous coefficients changed from 15 to 49 Nms/rad. Both of them tended to increase as the balance task became more demanding, i.e. in the order (a), (b) and (c).

Adult↗
PubMed1996

Dual-tracer autoradiography with thallium-201 and iodine-125-metaiodobenzylguanidine in experimental myocardial infarction of rat.

UNLABELLED: Dual-isotope scintigraphic studies with 201Tl and radioiodinated metaiodobenzylguanidine (MIBG) suggest that acute myocardial infarction causes extensive regional myocardial denervation beyond the infarcted area. We therefore investigated the histopathological and biochemical significance of the discrepancy between 201Tl and 125I-MIBG distribution determined by dual-tracer autoradiography in experimental myocardial infarction. METHODS: Left coronary arteries of 12 male Wistar rats were ligated for 30 min followed by reperfusion. Dual-tracer autoradiography of infarcted heart sections was performed with 201Tl and [125I]MIBG 4 hr or 2 days after coronary reperfusion, followed by immunohistochemical staining with myoglobin monoclonal antibody to determine the area of myocardial infarction. Ultrastructural alterations and myocardial norepinephrine (NE) content in the region determined by dual-tracer autoradiography and myglobin immunostaining were studied. RESULTS: Thirty-minute coronary ligation with 4-hr reperfusion produced myocardial infarction associated with discrepant region in the peri-infarcted myocardium characterized by decreased [125I]MIBG uptake and normal 201Tl distribution (discrepant region), as determined by dual-tracer autoradiography. In the discrepant region, which disappeared after 2 days, the nerve terminals showed loss of granular cores, with normal structures between normal myocytes. The mean myocardial NE level in the discrepant region was significantly lower than that in the nonischemic region (255.2 +/- 85.9 versus 549.5 +/- 82.5 ng/mg). CONCLUSION: The uptake discrepancy of 201Tl and [125I]MIBG observed in the infarcted heart represents a transient functional denervation of the regional cardiac sympathetic nerve terminals in the noninfarcted myocardium.

3-Iodobenzylguanidine↗
PubMed1996

[A case of benign cystic teratoma growing in the thoracic cavity].

A case with benign cystic teratoma growing in the thoracic cavity, which is rare in Japan, in a 49-year-old woman is reported. She complained a chest pain suddenly. Chest X-ray examination revealed an abnormal shadow and pleural effusion in the right lung field. Chest CT scan and MRI disclosed a capsulated tumor in the thoracic cavity. During surgery the tumor had adhered to the part of the parietal pleura with no continuity with anterior mediastinum. The tumor measured 11.0 x 9.5 cm in size and was a mature cystic teratoma with pancreatic tissue, histologically. The fluid levels of amylase extracted from the tumor was highly elevated. Rupture due to autodigestion by pancreatic amylase of the tumor was supposed to be a cause of chest pain.

Female↗
PubMed1996

Beneficial effect of amiloride, A Na(+)-H+ exchange blocker, in a murine model of dilated cardiomyopathy.

We investigated the effect of amiloride, a Na(+)-H+ exchange blocker, on ventricular hypertrophy in a murine model of dilated cardiomyopathy (DCM). Mice with DCM were given orally amiloride for 60 days. The ratio of heart weight to body weight and left ventricular cavity dimension were significantly smaller in both amiloride groups than those in furosemide and control (untreated DCM) groups (p < 0.05). The fiber diameter was significantly smaller in amiloride groups than that in furosemide group (p < 0.01). Plasma and cardiac angiotensin II (AII) levels were decreased in amiloride-treated groups compared with those in furosemide or control group (p < 0.05). Our findings suggest that amiloride prevents the development of myocardial hypertrophy and left ventricular dilatation in DCM in association with a reduction of AII.

Amiloride↗
PubMed1996

Amlodipine inhibits the development of right ventricular hypertrophy and medial thickening of pulmonary arteries in a rat model of pulmonary hypertension.

This study was designed to evaluate the effects of amlodipine, a new calcium channel blocker, on the development of right ventricular hypertrophy and thickening of the media of the pulmonary arteries in a rat model of pulmonary hypertension. Pulmonary hypertension was induced in rats by administering a single injection of monocrotaline, 80 mg/kg. The oral administration of amlodipine, 3, 10, or 30 mg/kg/day, was initiated 24 hours later (day 1). On day 28 of therapy, we determined the right ventricular systolic pressure (RVSP), the mass ratio of the right ventricle (RV) to the left ventricle, the thickness of the wall of the RV, the diameter of myocardial fibers in the RV, the percent thickness of the media of the pulmonary artery, and the percent area of smooth muscle in the pulmonary arteries. The magnitude of all parameters was significantly less in the rats administered amlodipine, 30 mg/kg/day, vs. the control group given monocrotaline alone. RVSP, the percent medial thickness, and the percent smooth muscle area, were significantly lower in rats administered a dose of amlodipine, 30 mg/kg/day vs. 10 mg/kg/day. The oral administration of amlodipine, 30 mg/kg/day, inhibited the development of RV hypertrophy and medial thickening of the pulmonary arteries in rats exposed to monocrotaline significantly more effectively vs. the untreated control exposed only to monocrotaline.

Amlodipine↗
PubMed1996

Large vertebral body, in addition to narrow spinal canal, are risk factors for cervical myelopathy.

It is well known that a narrow spinal canal is frequently associated with cervical spondylotic myelopathy. However, few investigators have studied the relationship between the size of the cervical spinal canal and that of the cervical spinal cord. Moreover, no studies mention the correlation between the size of the vertebral body and that of the spinal canal in the pathogenesis of cervical myelopathy. In the present study, we used computed tomographic myelography to measure the size of the vertebral body, spinal canal, and spinal cord in patients who had classic cervical myelopathy and in control subjects. We found that patients with cervical spondylotic had a narrow spinal canal as well as a slender spinal cord in the cervical region. Moreover, the vertebral body is significantly larger in the myelopathy group than in controls. A large vertebral body is thought to be associated with a large osteophyte and large disc protrusion. We conclude that a large vertebral body is another risk factor for cervical myelopathy, along with a narrow spinal canal.

Adult↗
PubMed1996

[Pathological evaluation of superselective one-shot intra-arterial infusion chemotherapy for head and neck tumors].

Since 1992, we have treated 43 patients with head and neck tumors by superselective intra-arterial infusion chemotherapy (SIIC) via femoral artery. In 8 patients among then, operation was performed thereafter with/without radiation therapy (RT). CDDP and/or CBDCA were utilized as the chemotherapeutic modality. Only SIIC or RT showed Grade (Gr.) 0-2b pathological effects on Oboshi-Shimosato classification scheme, while a combination of SIIC and RT exhibited Gr. 2b-4 pathological effects. We conclude that a combination of SIIC and RT was most effective and had induced degeneration or necrotic changes in the tumor tissue.

Adult↗
PubMed1996

Localization of binding sites of Ulex europaeus I, Helix pomatia and Griffonia simplicifolia I-B4 lectins and analysis of their backbone structures by several glycosidases and poly-N-acetyllactosamine-specific lectins in human breast carcinomas.

Several studies have shown the deletion of blood group A or B antigens and the accumulation of H antigens in human breast carcinomas. Other studies have independently demonstrated that the binding sites of lectins such as Helix pomatia agglutinin (HPA) and Griffonia simplicifolia agglutinin I-B4 (GSAI-B4) are highly expressed in these cells. In order to clarify the molecular mechanisms of malignant transformation and metastasis of carcinoma cells, it is important to understand the relationship between such phenotypically distinct events. For this purpose, we examined whether the binding sites of these lectins and Ulex europaeus agglutinin I (UEA-I) are expressed concomitantly in the same carcinoma cells and analyzed their backbone structures. The expression of the binding sites of these lectins was observed independently of the blood group (ABO) of the patients and was not affected by the histological type of the carcinomas. Observation of serial sections stained with these lectins revealed that the distribution of HPA binding sites was almost identical to that of GSAI-B4 in most cases. Furthermore, in some cases, UEA-I binding patterns were similar to those of HPA and GSAI-B4 but in other cases, mosaic staining patterns with these lectins were also observed, i.e., some cell clusters were stained with both HPA and GSAI-B4 but not with UEA-I and adjacent cell clusters were stained only with UEA-I. Digestion with endo-beta-galactosidase or N-glycosidase F markedly reduced the staining intensity of these lectins. Together with the reduction of staining by these lectins, reactivity with Griffonia simplicifolia agglutinin II appeared in carcinoma cells following endo-beta-galactosidase digestion. Among the lectins specific to poly-N-acetyllactosamine, Lycopersicon esculentum agglutinin (LEA) most vividly and consistently stained the cancer cells. Next to LEA, pokeweed mitogen agglutinin was also effective in staining these cells. Carcinoma cells reactive with these lectins corresponded well to those stained with both HPA and GSAI-B4, and in some cases, with UEA-I. These results demonstrate that the binding sites of UEA-I, HPA, and GSAI-B4 are expressed concomitantly in the same carcinoma cells and all carry linear and branched poly-N-acetyllactosamine on N-glycans, suggesting that the synthesis of this complex carbohydrate is one of the most important and basic processes leading to the malignant transformation of cells, invasion, and metastasis of carcinoma cells.

ABO Blood-Group System↗
PubMed1996

[Simultaneous measurement of the tension, elongation, and refractive power of the bovine lens zonule].

We developed a device to measure simultaneously the tension and elongation of the lens zonules, and the refractive power of the lens in 12 bovine eyes. Each sample, which consisted of the lens-zonuleciliary body was fixed to the device at the position of the ciliary process from four directions, and was stretched radially in a container filled with saline solution. The tension was measured by a force transducer, the elongation by a laser-displacement-meter, and the refractive power by a Campbell type refractometer. The refractive power of the lens in the relaxed condition was 24.6 +/- 3.4 D (n = 12, mean +/- standard deviation). When samples were stretched 1 mm from the relaxed condition, the increased change in tension was 2.8 +/- 1.5 g, and the decreased change in refractive power was 1.8 +/- 1.2 D.

Animals↗
PubMed1996

Light microscopic histochemical and immunohistochemical localisation of sulphated glycosaminoglycans in the rooster comb and wattle tissues.

Comb and wattle tissues, which consist of layers of epidermis, dermis and central connective tissue, are known to contain sulphated glycosaminoglycans (GAGs) including dermatan sulphate and chondroitin sulphate-dermatan sulphate copolymers. Little is known about distribution of these CAGs in each tissue. The objective of this study was to localise sulphated GAGS in the comb and wattle tissues from mature roosters. Monoclonal antibodies 6D6, CS-56 and AH12 specific to dermatan sulphate proteoglycan (decorin), chondroitin sulphate and keratan sulphate, respectively, were used. In both tissues, 6D6 epitope was found to be more concentrated in the superficial layer of dermis and the central connective tissue than in the intermediate layer of dermis containing fibromucoid tissue. The staining pattern for 6D6 epitope was similar to that for collagen fibres. In contrast, CS-56 epitope was uniformly distributed in most parts of the dermis and the central connective tissue. The stratum germinativum in the epidermis was the major tissue showing positive staining with AH12, haematoxylin and safranin-O.

Animals↗
PubMed1996

[Performance study of teleradiology network systems with CRT monitors: ROC analysis of an observation study of simulated lung nodules].

PURPOSE: To evaluate the diagnostic performance of commercially available CRT monitors used in a teleradiology system by determining the rate of detection of simulated lung nodules. MATERIALS AND METHODS: Three types of CRT monitors were tested in the observation study. They had matrix sizes of 1024 x 768(16 inches, color), 1024 x 768(20 inches, color) and 1600 x 1125(24 inches, black and white). Twenty chest radiographs were obtained by Fuji computed radiography(FCR) of an anthropomorphic chest phantom with ten simulated nodules on its surface. These FCR films were digitized by a film digitizer with 125 DPI(1024 x 1024 matrix sizes)and 12 bit gray scales, and the image data were transferred from Shinshu University Hospital to other hospitals where interpretation was carried out by the radiologists. Ten radiologists of three hospitals were asked to interpret independently both the original FCR films and the images shown on the CRT monitors and to indicate the presence or absence of simulated nodules on the images by using a five-category rating scale. Receiver operating characteristics(ROC)curves were generated, and the results of interpretation on the FCR films and CRT monitors were compared. RESULTS: Performance of the all readers was slightly better with the CRT monitors than on the FCR films, although the differences were not statistically significant. There were no statistically significant differences in performance depending on the type of CRT monitor. CONCLUSION: Performance of the CRT monitors was comparable to that of FCR radiography in terms of interpreting the simulated lung nodules.

Computer Communication Networks↗
PubMed1996

Immunological role of human palatine tonsil in Epstein-Barr virus persistence.

To determine whether EBV-specific cellular immunity persists and controls EBV in the palatine tonsil, we compared EBV-specific cellular immune responses in the palatine tonsil and peripheral blood. In 32 EBV-seropositive donors, we performed in vitro growth inhibition assays of EBV-induced B-lymphocyte transformation (regression assay). The results showed that EBV-specific cytotoxic T lymphocytes (CTL) precursor frequency was higher in the palatine tonsil than in the peripheral blood. After a first stimulation with autologous lymphoblastoid cell line (LCL), the EBV-specific cytotoxicity of reactivated CTL was higher in the palatine tonsil than in the peripheral blood. Furthermore EBV-specific CTL lines established from the palatine tonsil had significantly higher EBV-specific cytotoxicity in comparison with those from the peripheral blood. Both the EBV-specific CTLs from tonsils and peripheral blood were restricted by HLA class-I determinants. These data indicate that the palatine tonsil, which is frequently exposed to EBV, plays an important role in controlling EBV infection in the oropharynx.

Adult↗
PubMed1995

Superselective cisplatin (CDDP)-carboplatin (CBDCA) combined infusion for head and neck cancers.

A group of 26 patients with carcinoma of the head and neck region was treated by superselective intra-arterial infusion of cisplatin (CDDP)-carboplatin (CBDCA). The tumor locations included the tongue (n = 4), oral base (n = 2), nasopharynx (n = 2), oropharynx (n = 8), hypopharynx (n = 4) and larynx (n = 4). Using the coaxial technique, a microcatheter was placed in the lingual, ascending pharyngeal, facial and superior thyroidal arteries according to the location of the tumor. Under imaging studies, CDDP (50 mg/m2)-CBDCA (300 mg/m2) was infused into the vessel, via injectors at the rate of 12.5 ml/min. One to five injections were given every 4 weeks. During and following the chemotherapy the patients received radiotherapy (n = 22), surgery (n = 4) or both (n = 3). Sixty-six sessions of intra-arterial chemotherapy were given with no major complications. Drug-related systemic side effects were mild. The overall response rate was 96% (complete response (CR) 50% and partial response (PR) 46%). Superselective CDDP-CBDCA combined infusion is feasible, relatively non-toxic, and important as multimodality therapy.

Adult↗