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Biomedical subjects

T Hosoya

Publications and source records attributed to T Hosoya.

At least 145 records · Page 8Linked to original sources
PubMed1997

Biological activities of novel zaragozic acids, the potent inhibitors of squalene synthase, produced by the fungus, Mollisia sp. SANK 10294.

Four novel zaragozic acids, F-10863A, B, C and D, were isolated from a culture broth of the fungus Mollisia sp. SANK 10294. F-10863 compounds contain a 4,6,7-trihydroxy-2,8-dioxyobicyclo-[3.2.1]octane-3,4,5-tricarboxyl ic acid core like previously reported zaragozic acids, but the structures of the side chains are different. Recently, it was found that F-10863A is identical to zaragozic acid D3, while the other three are novel compounds. F-10863 compounds are potent inhibitors of squalene synthase like previously reported zaragozic acids, and, furthermore, they exhibit serum cholesterol-lowering activity in vivo.

Animals↗
PubMed1997

Arterial dissection of the vertebrobasilar systems: a possible cause of acute sensorineural hearing loss.

OBJECTIVE: Our goal was to describe three cases of acute sensorineural hearing loss (ASNHL) that might be caused by arterial dissection of the vertebrobasilar system. DESIGN: Retrospective case review. SETTING: Yamagata University Hospital, Yamagata, Japan. PATIENTS: Thirty-seven patients with ASNHL underwent magnetic resonance (MR) imaging between September 1993 and March 1995. INTERVENTIONS: Proton density and T2-weighted axial images and three-dimensional spoiled gradient-recalled acquisition in steady state (3-D SPGR) imaging with gadopentetate dimeglumine were obtained with a 1.5 T MR system in all patients. T1-weighted images were obtained in 23 patients. Vertebral angiography (VAG) was performed in 4 of the 37 patients. RESULTS: In 3 of the 37 patients, the presence of vertebrobasilar dissection was confirmed: contrast-enhanced 3-D SPGR images disclosed double lumen of the proximal basilar artery and/or the ipsilateral vertebral artery in all of the 3 patients. In two of them, the vertebrobasilar dissection was also confirmed by VAG. The hearing loss of all three patients improved after the onset. Audiograms revealed no characteristic pattern of the initial hearing loss among them. CONCLUSIONS: Vertebrobasilar dissection may cause an intramural hematoma involving the orifice of the anterior inferior cerebellar artery or a distal thromboembolism reducing the blood flow of the labyrinthine artery; these conditions can lead to onset of hearing loss. Arterial dissection of the vertebrobasilar system might be one of the causes of ASNHL.

Adolescent↗
PubMed1997

[Usefulness of helical DIC-CT in pancreaticobiliary maljunction].

[PURPOSE]: To determine the usefulness of helical CT during drip infusion cholangiography (DIC-CT in patients with pancreaticobiliary maljunction. [MATERIALS AND METHODS]: DIC-CT was performed in six patients with pancreaticobiliary maljunction. After drip infusion of 100 ml of Iotroxic acid meglumine, helical CT was performed. One mm or 1.5 mm interval images were reformatted from the raw data. Thereafter, multi-plannar reconstruction (MPR) images were obtained from the reformatted images. The reformatted images and the MPR images were reviewed. [RESULTS]: In all cases, the form of the union was visualized. In two patients, a contrast defect was shown in the common bile duct arising from the union of the pancreatic duct. The defects were considered due to pancreatic juice reflux into the common bile duct. In the other two patients, the contrast medium in the common bile ducts was regurgitated into the pancreatic duct. [CONCLUSION]: DIC-CT was very useful in the evaluation of pancreaticobiliary maljunction, because of its functional characteristics, high resolution and three-dimensional data.

Acute Disease↗
PubMed1997

[A case of a ruptured lingual artery aneurysm treated with endovascular surgery].

A rare case of a ruptured lingual artery aneurysm treated with endovascular procedure in presented. A 67-year-old woman undergoing treatment in our hospital for right thalamic hemorrhage complained of sudden swelling in the submandibular area and breathlessness. The swelling was so rapid and progressive that her breathing was disturbed. She was intubated as soon as possible. Computed tomography (CT) showed a massive subcutaneous hematoma, extending from the left submandibular area to the neck, which had compressed the trachea to the right. CT with contrast medium showed extravasation of the medium for this lesion. Angiography showed that the aneurysm was located on the periphery of the left ingual artery. Extravasation of contrast medium from the aneurysm was also observed. We considered that direct surgery was difficult to perform safely, so we chose an endovascular procedure to treat this lesion. The lingual artery was successfully embolized using four platinum coils. No rebleeding or other complication occurred after the coil embolization. Disturbance of breathing due to air way obstruction is an important symptom of a ruptured lingual artery aneurysm. Endovascular surgery may be the first choice for treatment of the bleeding origin.

Aged↗
PubMed1997

[Steroid resistance and lung-tissue cytokines in experimental bleomycin-induced lung fibrosis].

To examine the mechanism of steroid resistance in lung fibrosis, cytokines expressed in the lung tissue of mice with bleomycin-induced lung fibrosis were studied. 1. Glucocorticoid administration (1 mg/kg/day) did not affect the grade of lung fibrosis induced by intratracheal injection of bleomycin (3.76 micrograms/g). 2. Cytokines expressed in the lung tissue were studied with the reverse-transcriptase polymerase chain reaction. Levels of promotor cytokines, such as TNF alpha, TGF beta, INF gamma, and IL-2, were significantly higher in lung tissue from the bleomycin group. The expression of these cytokines in the glucocorticoid group was low, especially the peak value. Expression of IL-4 was high in the bleomycin group, and was not inhibited in the glucocorticoid group. Expression of the down-regulator cytokine IL-10 was also high in the bleomycin group and very low in the glucocorticoid group. 3. The non-selectivity of glucocorticoids with respect to promotor and suppressive cytokines may account in part for steroid resistance in bleomycin-induced pulmonary fibrosis.

Animals↗
PubMed1997

[Comparative study of pre- and postoperative three-dimensional contrast-enhanced MRI with surgical finding in patients with hemifacial spasm].

The purpose of this study was to assess the utility of three-dimensional (3D) contrast-enhanced MRI in patients with hemifacial spasm. We performed preoperative MRI in 36 patients in whom microvascular decompression (MVD) was performed and postoperative MRI in 29. All MRI studies were obtained with a 1.5T MRI system using the spoiled GRASS (SPGR) method. In all patients, neurovascular compression of the facial nerve could be detected prior to MVD, and the rate of accuracy was 91.7%. Postoperative 3D-MRI was useful in confirming of displacement of the offending vessels and assessing of its severity.

Aged↗
PubMed1997

[Significance of residual renal functions of patients with end-stage renal failure undergoing continuous ambulatory peritoneal dialysis].

It is generally accepted that residual renal function remains well-preserved longer with CAPD than with hemodialysis. However, consideration and impact of the contributory effects of residual renal function on the adequacy of renal replacement therapy has not been well defined. In this report, creatinine clearance (Ccr), Kt/V, normalized protein catabolic rate (nPCR) and urinary excretion of uremic solutes were studied in 26 stable CAPD patients with a four-bag exchange. Weekly Ccr, weekly Kt/V and nPCR were 62.3 +/- 20.2 l/week/1.73 m2, 1.77 +/- 0.35, and 0.90 +/- 0.13 g/kg/day, respectively. These parameters correlated significantly with the daily urine volume. The weekly Ccr and Kt/V of anuric patients seemed to be inadequate. Urinary excretion of urea nitrogen, Cr, Na, Cl, Pi and beta 2-microglobulin (beta 2-MG) were dependent upon the daily urine volume. Significant phosphorus and beta 2-MG excretion seemed to have an effect on the prevention of bone and joint complications, because serum iPTH and beta 2-MG levels increased after the patients fell into an anuric state. It was suggested from this study that CAPD should be started before the patient loses residual renal function because four bag exchange as the standard CAPD prescription might not be adequate once the patient loses urine excretion.

Adult↗
PubMed1996

The gcm-motif: a novel DNA-binding motif conserved in Drosophila and mammals.

In the Drosophila nervous system, the glial cells missing gene (gcm) is transiently expressed in glial precursors to switch their fate from the neuronal default to glia. It encodes a novel 504-amino acid protein with a nuclear localization signal. We report here that the GCM protein is a novel DNA-binding protein and that its DNA-binding activity is localized in the N-terminal 181 amino acids. It binds with high specificity to the nucleotide sequence, (A/G)CCCGCAT, which is a novel sequence among known targets of DNA-binding proteins. Eleven such GCM-binding sequences are found in the 5' upstream region of the repo gene, whose expression in early glial cells is dependent on gcm. This suggests that the GCM protein is a transcriptional regulator directly controlling repo. We have also identified homologous genes from human and mouse whose products share a highly conserved N-terminal region with Drosophila GCM. At least one of these was shown to have DNA-binding activity similar to that of GCM. By comparing the deduced amino acid sequences of these gene products, we were able to define the "gcm motif," an evolutionarily conserved motif with DNA-binding activity. By PCR amplification, we obtained evidence for the existence of additional gcm-motif genes in mouse as well as in Drosophila. The gcm-motif, therefore, forms a family of novel DNA-binding proteins, and may function in various aspects of cell fate determination.

Amino Acid Sequence↗
PubMed1996

Localization of the gustatory pathway in the human midbrain.

The localization of the secondary gustatory pathway in the human brainstem still remains uncertain. Here we report two patients with small vascular lesions in the unilateral midbrain tegmentum who presented with taste disturbance on the ipsilateral side of the tongue. In both cases, the dorsomedial mesencephalic tegmental region lateral to the oculomotor nucleus, including the central tegmental tract and the ventral part of the periaqueductal gray, was involved commonly in the lesions. The secondary gustatory pathway arising from the nucleus of the solitary tract appears to run rostrally, without crossing, to the ipsilateral thalamic nucleus through the dorsomedial part of the tegmental region at the rostral level of the midbrain.

Adult↗
PubMed1996

Existence of novel branched side chains containing beta-1,2 and alpha-1,6 linkages corresponding to antigenic factor 9 in the mannan of Candida guilliermondii.

Isolation of beta-linkage-containing side chain oligosaccharides from the mannan of Candida guilliermondii IFO 10279 strain has been conducted by acetolysis under mild conditions. A structural study of these oligosaccharides by one- and two-dimensional NMR and methylation analyses indicated the presence of extended oligosaccharide side chains with two consecutive beta-1,2-linked mannose units at the nonreducing terminal of alpha-linked oligosaccharides. The linkage sequence present in this mannan, Man beta 1-->2Man alpha 1-->3Man alpha-->, has also been found in the mannan of Saccharomyces kluyveri but not in the mannan of Candida species. Furthermore, these oligosaccharides are branched at position 6 of the 3-O-substituted mannose units as follows. (Carbohydrate sequence in text) Structure 1 and (Carbohydrate sequence in text) Structure 2 The H-1 signals of the mannose units substituted by a 3,6-di-O-substituted unit showed a significant upfield shift (delta delta = 0.04-0.08 ppm) due to a steric effect. The inhibition of an enzyme-linked immunosorbent assay between the mannan of C. guilliermondii and factor 9 serum with oligosaccharides obtained from several mannans indicated that only the oligosaccharides with the above structure were active, suggesting that these correspond to the epitope of antigenic factor 9.

Antigens, Fungal↗
PubMed1996

Production of a novel monoclonal antibody, JT-95, which can detect antigen of thyroid carcinoma.

Monoclonal antibody (MAb) JT-95 was produced by immunization of mice with membrane fractions of a human thyroid carcinoma. Immuno-histochemical staining has demonstrated that the antigen recognized by JT-95 is strongly expressed in 95 (95%) of 100 cases of papillary carcinomas and in 3 (75%) of 4 cases of follicular carcinomas. In benign diseases of the thyroid gland, MAb JT-95 reacted with 0 (0%) of 39 adenomas, 1 (4%) of 21 adenomatous goiters, 0 (0%) of 8 hyperthyroidism specimens, and 3 (38%) of 8 chronic thyroiditis specimens. The antigen detected by MAb JT-95 has an apparent Mr 250,000 in thyroid carcinomas. Moreover, circulating antigen in thyroid carcinoma patients was detected by MAb JT-95 in an ELISA and in Western blotting. The circulating antigen has a Mr 105,000. MAb JT-95 conjugated with (131) I was administrated to nude mice bearing a human thyroid carcinoma. JT-95 131I accumulation at the transplanted tumor was visualized by autoradiography with 2.68-14.75-fold higher levels detected at the xenograft compared to that for normal organs. Based on these data, MAb JT-95 may be useful in the diagnosis detection and therapy of thyroid carcinoma.

Adenocarcinoma, Follicular↗
PubMed1996

Ill-defined focal low attenuation in the posterior internal capsule: a normal CT finding.

Although many pathological changes in the internal capsule may lead to neurological deficits, we often encounter ill-defined focal low attenuation in the posterior limb of the internal capsule (PIC) on CT in patients with no neurological disturbance. Brain CT studies of 141 patients without neurological deficits were reviewed to investigate the position of the focal low attenuation by analysis of a profile density curve. Nine patients with lacunar infarcts only within the posterior internal capsule were also studied. The focal low attenuation areas were ill-defined and bilaterally symmetrical, without mass effect. They were seen consistently within the posterior limb of the posterior internal capsule. Correlation between the distribution of these foci and the position of lacunar infarcts in the posterior internal capsule in nine patients with neurological deficits suggests that they may be related to the corticospinal tract.

Adult↗