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Biomedical subjects

T Hosoya

Publications and source records attributed to T Hosoya.

At least 127 records · Page 7Linked to original sources
PubMed1998

[The impact of low calcium dialysate (1.25 mmol/l; LCD) on bone metabolism in CAPD patients].

The aim of this study was to evaluate the influence of LCD on bone metabolism, and assess the indication of LCD. Fourteen patients on CAPD (m = 8, f = 6) were converted to LCD following over 1 year on standard calcium dialysate (1.75 mmol/l; SCD) treatment, and followed for 1 year. The biochemical measurements included plasma levels of Ca, P, ALP, and i-PTH. The bone mineral density (BMD) was evaluated using dual energy x-ray absorptiometry. Ca-carbonate and calcitriol were administered to maintain plasma Ca levels within the normal range. The patients were divided into three groups on the basis of the i-PTH levels just before the conversion to LCD. Group 1; n = 5, i-PTH < 65. Group 2; n = 5, 65 < or = i-PTH < 200. Group 3; n = 4, 200 < or = i-PTH (pg/ml). Mean BMD Z scores decreased significantly in group 3. Mean serum i-PTH significantly increased in all groups. These results suggest that LCD is effective for treating adynamic bone disease, which is seen in high frequency in patients undergoing peritoneal dialysis. However, these results also pointed to the disadvantage of worsening the secondary hyperparathyroidism. In conclusion, LCD should be used carefully in patients whose i-PTH levels are high, because of the possibility of bone mineral loss.

Adult↗
PubMed1998

[Primary non-Hodgkin's lymphoma of the uterine cervix complicated by acute renal failure due to ureter obstruction].

An 80-year-old woman was referred to our hospital because of irregular genital bleeding. An abnormal mass was found in the uterine cervix, and diagnosed as non-Hodgkin's lymphoma, diffuse large B cell type. Soon after admission, the patient became anuric and was given a diagnosis of acute renal failure due to obstruction of the ureter. She was immediately placed on dose-reduced CHOP and radiotherapy of 15 Gy. As a result, not only did the malignant lymphoma go into remission, but diminished renal function was alleviated. Because malignant lymphoma of the uterus is extremely rare, it exact biocharacteristics are not well understood. We are unaware of any previous report concerning uterine lymphoma complicated by renal failure.

Acute Kidney Injury↗
PubMed1998

LDL adsorption improves the response of focal glomerulosclerosis to corticosteroid therapy.

We investigated the therapeutic effect of low density lipoprotein adsorption (LDL-A) in 14 patients who had focal glomerulosclerosis (FGS) with the nephrotic syndrome resistant to steroids. Patients received a total of 6 sessions (2 times a week for 3 weeks). The levels of total cholesterol, triglycerides and low-density lipoprotein were decreased significantly after treatment (by approximately 50%) in all patients (p<0.01). There also seemed to be a possibility that LDL-A improved the response to steroid therapy. The glomerular filtration rate (GFR) increased from 54.4 +/-27.4 ml/min to 70.0+/-30.2 ml/min (p <0.05) and daily urinary protein excretion (Up/day) decreased from 7.24+/-3.58 g/day to 2.56 + 2.00 g/day (p<0.01). Up/day was significantly higher in patients who showed more than 30% improvement of GFR (n = 6) than in patients who showed less than 30% improvement of GFR (n = 7) (9.50+/-3.41 g/day vs 4.59+/-1.17 g/day, p<0.05). The decrease of urinary protein excretion was more marked in younger patients (29.4+/-11.9 vs 49.7+/-14.8, p <0.05). Only electron microscopy was able to detect histological recovery in the patients who showed a decrease of proteinuria after LDL-A therapy and light microscopy was not able to verify or accurately identify the histological response. In conclusion, LDL-A seems to be effective for FGS associated with nephrotic syndrome resistant to steroids, especially in younger patients. Histological assessment of the effect of this treatment requires electron microscopic examination.

Adrenal Cortex Hormones↗
PubMed1998

Hypererythropoietinemia and hyperreninemia in a continuous ambulatory peritoneal dialysis patient with chronic severe hypotension.

We experienced a patient on continuous ambulatory peritoneal dialysis (CAPD) who showed hypererythropoietinemia (Epo concentration: 86.7 mU/ml, normal range: 8-36 mU/ml), erythrocytosis, high renin concentration (26.5 pg/ml) and chronic hypotension. In this patient the erythrocytosis progressed along with exacerbation of the chronic severe hypotensive state. This patient had systemic circulatory insufficiency as suggested by the fact that he had a fibrous myocardium and an increased anion gap. We hypothesized that circulatory insufficiency due to chronic severe hypotension may lead to the stimulation of the Epo production, due to a decreased oxygen supply to peripheral tissues and/or to the stimulation of the renin angiotensin system even in patients with end-stage renal failure.

Aged↗
PubMed1998

[Aldehyde dehydrogenase 2(ALDH2) gene polymorphism in NIDDM patients with chronic renal failure].

In order to investigate the influence of aldehyde dehydrogenase 2(ALDH2) genotype in the pathogenesis of nephropathy due to non-insulin dependent diabetes mellitus (NIDDM), genotyping of ALDH2 was measured using the PCR-RFLP method in patients with NIDDM on chronic hemodialysis (HD). The results were as follows; 1) The frequency of active ALDH2 was 63% and that of inactive ALDH2 was 37%. 2) The percentage of active ALDH2 was significantly higher in patients with alcohol tolerance than that in those without it (38%). 3) The estimated amount of alcohol consumption in the past was 506 +/- 720 g/week in the active ALDH2 group, and 156 +/- 288 g/week in the inactive ALDH2 group, showing a significant difference between the two groups. 4) Interdialytic body weight gain was larger in patients with active ALDH2 than in those with inactive ALDH2. Since the frequency of active ALDH2 was similar to that in patients without nephropathy, these results do not support the hypothesis that ALDH2 gene polymorphism is involved in the development and persistence of chronic renal failure due to NIDDM. However, salt and water craving in dialysis patients may be influenced partially by an active ALDH2 gene.

Aged↗
PubMed1998

Edema along the optic tract: a useful MR finding for the diagnosis of craniopharyngiomas.

BACKGROUND AND PURPOSE: The pattern of edema caused by craniopharyngiomas and other common suprasellar masses could be useful for determining the differential diagnosis of lesions in this region. The purpose of this study was to ascertain whether the pattern of edema spread on MR images can be used in the diagnosis of craniopharyngiomas. METHODS: The preoperative MR images in eight consecutive patients with craniopharyngiomas, 15 patients with large pituitary adenomas compressing the optic chiasm, and six patients with tuberculum sellae meningiomas were evaluated. All the patients were treated surgically at our hospital and a pathologic diagnosis was obtained. We analyzed the spread of edema surrounding the tumor on the coronal dual-echo fast spin-echo images and compared this finding with tumor location and size as seen on contrast-enhanced T1-weighted images. RESULTS: Not only peritumoral edema but also edema spreading along the optic tracts was observed in five patients with craniopharyngiomas, one of whom also had edema within one optic nerve. The location of edema in the visual pathway was not always associated with the degree of visual disturbance. None of the patients with large pituitary adenomas or with tuberculum sellae meningiomas had such edema along the visual pathway. CONCLUSION: Edema caused by craniopharyngiomas tends to spread along the optic tracts. It is a useful MR finding for distinguishing craniopharyngiomas from other common parasellar tumors.

Adult↗
PubMed1998

[A case of vertebrobasilar dissection which was associated with progressing stroke and was successfully treated by intravascular surgery in the acute stage].

A case of vertebrobasilar dissection which deteriorated in the acute stage and was successfully treated by intravascular surgery is described. A 26-year-old male presented with sudden onset of occipitalgia, weakness of the right upper and lower extremities, and speech disturbance. He was transferred to our hospital 3 hours after the onset. On admission, neurological examination showed right hemiparesis including the face and dysarthria. CT of the head showed no definite abnormality and left vertebral angiograms (VAG) revealed only slight wall irregularity of the basilar artery. T2-weighted MR imaging demonstrated an area of high intensity in the left side of the pons. He was treated conservatively under a diagnosis of pontine infarction. On the 8th hospital day, he developed left hemiparesis. T2-weighted MR imaging revealed a new high intensity lesion in the opposite side of the pons. 3D-SPGR images showed double lumen of the left vertebral artery. Angiography showed that the wall irregularity of the basilar artery had become more obvious. These findings strongly suggested a dissection extending from the left vertebral artery to the basilar artery. Progression of the dissection was presumed to have caused the worsening in clinical symptoms, and further progression of the dissection would involve perforators of the basilar artery top and would be fatal. To prevent further progression of the dissection, the left vertebral artery was occluded at the proximal site of the orifice of the dissection with platinum coils after a test occlusion on the same day. Postoperatively, further deterioration of the clinical symptoms ceased. Left VAG on the 33rd postoperative day demonstrated improvement in the wall irregularity of the basilar artery. His clinical symptoms improved markedly and he was ambulatory at discharge and returned to his previous occupation. We emphasize that a progressive vertebrobasilar dissection that causes clinical deterioration in the acute stage can be prevented from progressing further by occlusion at the proximal site of the orifice of the dissection.

Adult↗
PubMed1997

Demonstration of the presence of alpha-1,6-branched side chains in the mannan of Candida stellatoidea.

A mild acetolysis of the mannans of Candida stellatoidea was performed after acetylation to yielded an alpha-1,6-branched mannohexaose, the presence of which had been predicted from the appearance of a specific H1-H2-correlated cross-peak in two-dimensional homonuclear Hartmann-Hahn spectroscopy. In this study, we found that the de-O-acetylation of a 4-O-acetyl group at the branching point, the 3,6-di-O-substituted mannose unit, of an acetylated oligosaccharide by sodium methoxide is significantly slower than that of other acetyl groups. We could separate the 4-O-acetylated branching oligosaccharide from linear isomer using high-performance liquid chromatography. Before and after the de-O-acetylation of the purified branching oligosaccharide, their 1H-NMR signals were sequentially assigned by means of the nuclear Overhauser effect. In the sequential NMR assignment study, we showed that the alpha-1,6-linked mannose unit is attached to the 3-O-substituted unit based on the presence of NOE cross-peak between H1 of the branching mannose unit and H6 of the 3-O-substituted mannose unit. An enzyme-linked immunosorbent inhibition assay of the reactivity of factor 4 serum to C. stellatoidea mannan by several oligosaccharides indicated that the alpha-1,6-branched oligosaccharide and the beta-1,2 linkage-containing oligosaccharides showed inhibitory activity. This result indicates that factor 4 serum, as well as factor 5 and 6 sera, contains antibodies against beta-1,2-linked mannose units which have been reported to participate in pathogenicity via cytokine production and/or adherence. From the assignment results of H1-H2-correlated cross-peaks of oligosaccharides and mannans, the molar ratio of the mannan side chains was proposed. In this study, we demonstrated that the epitope structure of the C. stellatoidea type I strains was the same as that of the C. albicans NIH B-792 (serotype B) strain.

Acetates↗
PubMed1997

Identification of two mutations in human xanthine dehydrogenase gene responsible for classical type I xanthinuria.

Hereditary xanthinuria is classified into three categories. Classical xanthinuria type I lacks only xanthine dehydrogenase activity, while type II and molybdenum cofactor deficiency also lack one or two additional enzyme activities. In the present study, we examined four individuals with classical xanthinuria to discover the cause of the enzyme deficiency at the molecular level. One subject had a C to T base substitution at nucleotide 682 that should cause a CGA (Arg) to TGA (Ter) nonsense substitution at codon 228. The duodenal mucosa from the subject had no xanthine dehydrogenase protein while the mRNA level was not reduced. The two subjects who were siblings with type I xanthinuria were homozygous concerning this mutation, while another subject was found to contain the same mutation in a heterozygous state. The last subject who was also with type I xanthinuria had a deletion of C at nucleotide 2567 in cDNA that should generate a termination codon from nucleotide 2783. This subject was homozygous for the mutation and the level of mRNA in the duodenal mucosa from the subject was not reduced. Thus, in three subjects with type I xanthinuria, the primary genetic defects were confirmed to be in the xanthine dehydrogenase gene.

Adult↗
PubMed1997

Binding of iodide to Arthromyces ramosus peroxidase investigated with X-ray crystallographic analysis, 1H and 127I NMR spectroscopy, and steady-state kinetics.

The site and characteristics of iodide binding to Arthromyces ramosus peroxidase were examined by x-ray crystallographic analysis, 1H and 127I NMR, and kinetic studies. X-ray analysis of an A. ramosus peroxidase crystal soaked in a KI solution at pH 5.5 showed that a single iodide ion is located at the entrance of the access channel to the distal side of the heme and lies between the two peptide segments, Phe90-Pro91-Ala92 and Ser151-Leu152-Ile153, 12.8 A from the heme iron. The distances between the iodide ion and heme peripheral methyl groups were all more than 10 A. The findings agree with the results obtained with 1H NMR in which the chemical shift and intensity of the methyl groups in the hyperfine shift region of A. ramosus peroxidase were hardly affected by the addition of iodide, unlike the case of horseradish peroxidase. Moreover, 127I NMR and steady-state kinetics showed that the binding of iodide depends on protonation of an amino acid residue with a pKa of about 5.3, which presumably is the distal histidine (His56), 7.8 A away from the iodide ion. The mechanism of electron transfer from the iodide ion to the heme iron is discussed on the basis of these findings.

Crystallography, X-Ray↗
PubMed1997

Magnetic resonance imaging in acute optic neuropathy by sphenoidal mucocele.

A 45-year-old man suffered sudden visual loss with Marcus-Gunn pupil and a central scotoma in the right eye as evaluated by visual field examination. The patient's right visual acuity was 0.02 (0.08 x -4.5 D). T1-weighted magnetic resonance imaging (MRI) demonstrated a cystic lesion of high intensity in the right sphenoid sinus. Short T1 inversion recovery (STIR) images presented a cystic lesion of high intensity in the right sphenoid sinus. In addition, a ring-shaped high intensity signal was seen surrounding the right optic nerve. Post-contrast fat suppression T1-weighted images did not demonstrate any enhancement within the right optic nerve. After intranasal sphenoidectomy, good recovery of the right visual acuity was noted. On subsequent MRI, the cystic lesion in the sphenoid sinus disappeared. Also, the ring of high intensity surrounding the right optic nerve became unclear. It was thought that the ring of hyperintensity seen on the STIR images demonstrated cerebrospinal fluid in the dilated perioptic subarachnoid space. Therefore, these MRI findings suggested that the acute visual loss resulted from a disturbed blood supply to the optic nerve due to compression by the sphenoidal mucocele, and not due to an inflammatory process.

Humans↗
PubMed1997

Prognostic factors of hemophagocytic syndrome in adults: analysis of 34 cases.

Hemophagocytic syndrome (HPS) presents with fever, pancytopenia, liver dysfunction and increase in hemophagocytic histiocytes in various organs. Although there are two major classifications of HPS in adults, malignant and reactive histiocytosis, it is often very difficult to distinguish between these disorders. We analyzed the laboratory data of patients with HPS to evaluate prognostic factors. Of 34 patients, 14 survived, and 20 died. The median age of survivors was 29.6+/-11.5 yr significantly younger than those who died (54.7+/-17.8 yr). Twenty patients had no obvious underlying disease, the other 13 had hematological malignancies or viral infections. Comparison of laboratory data revealed that nonsurvivors had significantly lower Hb and platelet values on admission. During treatment, worsening of anemia and thrombocytopenia, increase of transaminase and biliary enzymes were similarly more prominent. Risk factors associated with death were: age over 30 yr, presence of disseminated intravascular coagulation, increased ferritin and beta2-microglobulin, anemia accompanied by thrombocytopenia and jaundice. Our data suggests that patients with HPS and any of these risk factors should be treated aggressively with sufficient chemotherapy and supportive care.

Adolescent↗