Biomedical subjects

T Hosoya

Publications and source records attributed to T Hosoya.

At least 181 records · Page 10Linked to original sources

PubMed1995

Newly discovered familial juvenile gouty nephropathy in a Japanese family.

Our attention was initially called to 2 young Japanese sisters with gout and renal insufficiency, which led to an investigation of members of their family with similar conditions. One sister, a 26-year-old woman who had suffered from polyuria since infancy, suffered from gout and renal insufficiency. Her younger sister also had a history of polyuria, hyperuricemia, and moderately reduced renal function. Their urinary uric acid levels were reduced but purine enzyme activities in the erythrocytes were normal. A renal biopsy specimen from the younger sister showed severe interstitial fibrosis with tubular atrophy. An investigation of the family revealed an autosomal dominant transmission pattern. We believe these are new familial cases of juvenile gouty nephropathy found in a Japanese family.

Adult↗

PubMed1995

Familial thyroxine-binding globulin deficiency associated with hyperthyroidism.

A 24-year-old woman with familial thyroxine-binding globulin (TBG) deficiency associated with hyperthyroidism is reported. Thyroid-stimulating hormone (TSH)-binding inhibitor immunoglobulin (TBII) was negative, whereas thyroid-stimulating antibody (TSAb) was positive. Serum thyroxine-binding globulin (TBG) levels were extremely low, and remained low even after the normalization of thyroid function with methimazole (MMI) treatment. The serum TBG level of the mother of patient was also below the normal lower limit. Genetic analysis revealed single nucleotide deletion, common among Japanese with complete TBG deficiency (TBG-CD), from the allele-specific amplification of the TBG genes of the patient.

Adult↗

PubMed1995

Changes in renal function with aging among Japanese.

Renal function was assessed in 329 inpatients who were presumably free of renal disease or water-electrolyte imbalance and the relationship between renal function and aging and sexual differences were investigated. Serum creatinine levels were slightly increased with aging, and were significantly higher in males than in females. Urinary creatinine excretion significantly decreased with aging; this decline was more pronounced in males. Urinary creatinine excretion was significantly higher in males. Creatinine clearance also decreased significantly with aging and this tendency was still observed after correction for body surface area. Sexual differences played no part in creatinine clearance. There was a significant increase in the serum beta 2-microglobulin level with aging. In addition, the Cer of the aged Japanese population was lower in comparison with western counterpart. The findings suggest the need for special consideration in conducting clinical tests or administering drugs to this segment of the population in Japan.

Age Factors↗

PubMed1995

Trachyspic acid, a new metabolite produced by Talaromyces trachyspermus, that inhibits tumor cell heparanase: taxonomy of the producing strain, fermentation, isolation, structural elucidation, and biological activity.

Trachyspic acid, a new metabolite that inhibited heparanase, was isolated from the culture broth of Talaromyces trachyspermus SANK 12191. Its structure was deduced from NMR spectral analyses and chemical reactions as a tricarboxylic acid derivative containing a spiroketal. The IC50 value of trachyspic acid against heparanase was 36 microM.

Ascomycota↗

PubMed1995

[An epidemiologic study on pathogenesis of uric acid urolithiasis].

We reviewed 5477 patients with urinary calculi who presented during the years from 1975 to 1993. During this time the percentage of calcium stones has remained at approximately 86%. However over the same period the rate of urinary calculi composed of uric acid has increased and is now about 7.2%. The number of uric acid stones has increased 3.5 times compared to 1975. 355 of 394 (90.1%) with uric acid stones are male. We believe that the increase in the numbers of patients seen with gout, hyperurisemia of a high alcohol intake.

Alcohol Drinking↗

PubMed1995

[A case of multiple cerebral mycotic aneurysms treated with endovascular surgery].

A case of multiple mycotic cerebral aneurysms successfully treated with endovascular surgery is reported. A nine-year-old boy who has suffered from hypertrophic obstructive cardiomyopathy and active infectious endocarditis in the mitral valve developed sudden consciousness disturbance and convulsion. Computerized tomography revealed subarachnoid hemorrhage with subcortical hematoma in the left parietal lobe. Angiography demonstrated four aneurysms at the distal part of the middle cerebral artery on both sides. Since his physical status had been deteriorating, it was difficult to undergo a usual surgical operation. Therefore, endovascular surgery was performed. The catheter was super-selectively advanced to the parent artery of the left posterior parietal artery aneurysm which seemed to be the hemorrhagic source, and the embolization was performed using platinum coils and liquid embolization material. Angiography after embolization showed that the aneurysms had been successfully occupied by the materials while the aneurysm of the right anterior parietal artery had not responded antibiotic therapy. Therefore the second embolization was carried out to the parent artery of the aneurysm of the right anterior parietal artery one month later. The patient had no neurological deficit after embolization and no aneurysms have been detected by the follow-up angiogram after the second embolization. An endovascular approach might be an alternative useful treatment for cases in which the patient has, deteriorated so much that it is considered difficult to perform open craniotomy under general anesthesia.

Aneurysm, Infected↗

PubMed1994

[Non-calcified line in calcification of the globus pallidus].

In recent years, high resolution X-ray CT has provided detailed information on calcification of the basal ganglia. At this institution, a review of 30 patients with 57 globus pallidus calcifications revealed curvilinear non-calcified lines in 19 calcifications. These were considered to be the medial medullary lamina of the globus pallidus. An attempt was made to classify calcifications of the globus pallidus into calcifications of the medial and lateral segments by the non-calcified line or location of the calcification, and to assess the tendency to calcify of both the medial and lateral segments. The results of this assessment revealed that the lateral segment tended to calcify more than the medial segment.

Adult↗

PubMed1994

Isolation and characterization of a gene for a ryanodine receptor/calcium release channel in Drosophila melanogaster.

The nucleotide sequence of a 25.7 kilobase Drosophila melanogaster genomic DNA segment containing a gene for a ryanodine receptor/calcium release channel homologue has been determined. Computer analysis and partial cDNA cloning revealed 26 exons comprising the protein-coding sequence in this gene. The predicted protein is homologous in amino acid sequence and shares characteristic structural features with the mammalian ryanodine receptors. In blot hybridization analysis, a approximately 16 kilobase RNA species was identified abundantly in a 6-12 h embryo as the transcript from this gene. In situ hybridization to polytene chromosomes indicated that this gene locates at band position 44F on the second chromosome.

Amino Acid Sequence↗

PubMed1994

Isolation of thyroid peroxidase from patients with Graves' disease and comparison with animal peroxidases.

1. Human thyroid peroxidase (TPO) was isolated from 280-640 g of pooled thyroid tissue resected from patients with Graves' disease. 2. Isolation was performed by an improved and simplified method. 3. The Reinheit Zahl (A412/A280) of the final preparations was in the range of 0.16-0.32. 4. The spectroscopic and enzymatic properties of Graves' TPO were compared with those of porcine TPO and bovine LPO, revealing closer resemblance to the former. 5. Graves' TPO may provide a useful substitute for normal TPO, which is very difficult to isolate.

Animals↗

PubMed1994

A Drosophila homolog of human proto-oncogene ret transiently expressed in embryonic neuronal precursor cells including neuroblasts and CNS cells.

We have identified a Drosophila gene encoding a putative receptor tyrosine kinase by screening a genomic DNA library with a DNA probe for a Drosophila homolog of fibroblast growth factor receptors. The newly isolated gene codes for a transmembrane protein most similar in sequence to a mammalian proto-oncogene ret; thus, the gene was termed Dret. Dret mRNA is transcribed in very small amounts in the embryonic, larval, and pupal stages. Whole mount in situ hybridization experiments revealed that the mRNA is transiently expressed in neuroblasts in early embryos. In late embryos, Dret mRNA was detected in subpopulations of differentiating CNS and PNS cells. In addition, Dret expression was affected in neurogenic mutants. These results suggest that Dret can be considered as a functional homolog of mammalian ret and should play important roles in neurogenesis.

Amino Acid Sequence↗

PubMed1994

Congenital euthyroid goitre with impaired thyroglobulin transport.

A case of congenital goitre with defective thyroglobulin (Tg) synthesis was studied from the clinical, biochemical and morphological perspectives. The patient, 5.5-year-old boy, who was clinically euthyroid, showed a positive perchlorate discharge test (37.2%). However, the iodination system seemed to be normal since radioiodine uptake into the thyroid was very high, and inspection of the H2O2-generating system using thyroid slices and an assay for peroxidase activity in microsomes showed no abnormalities. On the other hand, virtually no Tg was detected in the serum, and the amount of Tg in thyroid tissue, estimated with gel electrophoresis, was below 10% of the normal value, the quality of Tg being unchanged. Morphological observations demonstrated the presence of Tg in the markedly distended rough endoplasmic reticulum of the cytoplasm of follicular cells and a lack of Tg in the colloid of the follicular lumen. These results suggest that the thyroid is defective in Tg synthesis, probably associated with impaired transport of Tg from the cells to the lumen.

Child, Preschool↗

PubMed1994

[A case of Klippel-Trenaunay-Weber syndrome associated with intracranial multiple angiomas].

A case of Klippel-Trenaunay-Weber syndrome associated with multiple intracranial angiomas was reported. Intracranial angiomas with Klippel-Trenaunay-Weber syndrome is very rare. Only 4 cases are known to this day. A 24-year-old man fell at his workplace and suffered a head injury. He was admitted to our hospital. Neurological examination revealed no abnormality. However, physiological examination demonstrated hyperplasia and cutaneous hemangiomas of left lower leg, malformation of the left eyelid and clouding of the left cornea. CT showed left hemispheric atrophy and subdural effusion. MRI demonstrated multiple flow voids at the left cerebellar hemisphere and at pons. Cerebral angiogram demonstrated left cerebellar AVM and pontine angioma. Feeding arteries of the AVM were left superior cerebellar artery and left posterior inferior cerebellar artery. Those of the pontine angioma could not be identified. No spinal angiomas were revealed. While spinal angiomas associated with this syndrome are known, association of intracranial lesions are rare. Reported anomalies are angiomas, hemi-hypertrophy of skull and brain, carotid occlusion, megadolicoanomaly of the basilar artery, meningioma and glioma. Our case report with cerebral angiomas is the first one in Japan. We postulate that anomaly of our case originated at the Streeter's 2nd-3rd stage or that multiple anomalies occurred. We emphasize that intracranial, spinal or visceral angiomas, which can be fatal if it bleeds, should be routinely examined in Klippel-Trenaunay-Weber syndrome.

Adult↗

PubMed1994

Intracranial vertebral artery dissection in Wallenberg syndrome.

PURPOSE: To assess the prevalence of vertebral artery dissection in Wallenberg syndrome. METHODS: Sixteen patients (12 men, 4 women; mean age at ictus, 51.6 years) with symptoms of Wallenberg syndrome and an infarction demonstrated in the lateral medulla on MR were reviewed retrospectively. The study items were as follows: (a) headache as clinical signs, in particular, occipitalgia and/or posterior neck pain at ictus; (b) MR findings, such as intramural hematoma on T1-weighted images, intimal flap on T2-weighted images, and double lumen on three-dimensional spoiled gradient-recalled acquisition in a steady state with gadopentetate dimeglumine; (c) direct angiographic findings of dissection, such as double lumen, intimal flap, and resolution of stenosis on follow-up angiography; and (d) indirect angiographic findings of dissection (such as string sign, pearl and string sign, tapered narrowing, etc). Patients were classified as definite dissection if they had reliable MR findings (ie, intramural hematoma, intimal flap, and enhancement of wall and septum) and/or direct angiographic findings; as probable dissection if they showed both headache and suspected findings (ie, double lumen on 3-D spoiled gradient-recalled acquisition in a steady state or indirect angiographic findings); and as suspected dissection in those with only headache or suspected findings. RESULTS: Seven of 16 patients were classified as definite dissection, 3 as probable dissection, and 3 as suspected dissection. Four patients were considered to have bilateral vertebral artery dissection on the basis of MR findings. CONCLUSIONS: Vertebral artery dissection is an important cause of Wallenberg syndrome.

Adult↗

PubMed1993

Drosophila retinal degeneration A gene encodes an eye-specific diacylglycerol kinase with cysteine-rich zinc-finger motifs and ankyrin repeats.

The Drosophila visual mutant, carrying the retinal degeneration A gene (rdgA), has photoreceptor cells that degenerate within a week after eclosion. Morphological studies suggested that this mutant harbors abnormalities in membrane turnover of the photoreceptor cells. Biochemically, the rdgA mutant lacks an eye-specific and membrane-associated diacylglycerol kinase (DGK; EC 2.7.1.107) activity in a gene-dosage-dependent manner, suggesting that rdgA gene encodes a DGK. We report the molecular cloning and characterization of a DGK gene, which maps to the rdgA locus. This gene, designated as DGK2, has a single open reading frame that encodes 1454 amino acids. Like porcine DGK, DGK2 has two cysteine-rich zinc-finger motifs as well as a DGK catalytic domain. The DGK2 protein contains four ankyrin-like repeats at the C-terminal region, suggesting that DGK2 is likely anchored to the membrane or cytoskeleton. Northern blot analysis and tissue in situ hybridization to adult sections revealed that DGK2 is expressed exclusively in the adult retina and that the amount of its mRNA is reduced in some of the rdgA mutant alleles. Furthermore, in two rdgA alleles, rdgA1 and rdgA2, nonsense and missense mutations occur within their DGK2 gene, respectively. Thus, we conclude that rdgA encodes an eye-specific DGK, the absence of which leads to rhabdomere degeneration due to defective phospholipid turnover.

Amino Acid Sequence↗

PubMed1993

Cloning of the cDNA encoding human xanthine dehydrogenase (oxidase): structural analysis of the protein and chromosomal location of the gene.

The primary structure of human xanthine dehydrogenase (hXDH) was determined by cloning and sequence analysis of the cDNAs encoding the enzyme. The nucleotide (nt) sequence has an open reading frame of 3999 nt encoding a protein of 1333 amino acids (aa) with a calculated M(r) of 146,604. The deduced aa sequence of hXDH is homologous to the previously reported rat XDH (rXDH) and Drosophila melanogaster XDH sequences with identities of 90.2 and 52.0%, respectively. The aa residues involved in both the reversible and the irreversible conversion from the dehydrogenase type to the oxidase type of rXDH are completely conserved between the rat and the human enzymes. This implies that the molecular mechanisms of the conversion of hXDH from dehydrogenase to oxidase are common to those of the well-characterized rXDH. Five sequence variations were detected in the isolated cDNA clones. Spot blot hybridization using flow-sorted human chromosome revealed that the hXDH-encoding gene (hXDH) was located on chromosome 2.

Amino Acid Sequence↗

PubMed1993

[Cerebral edema extending to the posterior limb of the internal capsule on MR imaging].

The features of edema extending to the posterior limb of the internal capsule (PLIC) were investigated in a review of MR imaging (MRI), with the following results. Edema was seen along the lateral and medial margins of the PLIC, although the PLIC itself was resistant to edema. The edema along the lateral and medial margins tended to extend into the lentiform nucleus and thalamus, respectively, and was considered to be edema of the extrapyramidal and thalamocortical tracts. When edema was abundant, the PLIC was traversed by many edematous tracts which seemed to connect the lentiform nucleus with the thalamus. The PLIC looked like a comb, and this finding was a good anatomical landmark on MR T 2-weighted images. We have used the term "comb appearance" to describe this finding.

Brain↗

PubMed1993

Limited proteolysis of rat liver nucleolin by endogenous proteases: effects of polyamines and histones.

Nucleolin is a major nucleolar phosphoprotein and is presumably involved in rDNA transcription and ribosome biosynthesis. This protein is known to be very labile and to be cleaved by endogenous proteases into many small peptides. We found that, when rat liver nucleolar suspension (Nu-1) or nucleolin-rich extract (Nu-2) was incubated under conventional conditions, polyamines and histones interacted with the nucleolin to lead to its preferential degradation to 60 kDa phosphopeptide (p60). The peptide p60 was identified as a peptide containing the N-terminal half of the nucleolin molecule, as judged from peptide-map analysis. Whereas spermine binding to the purified nucleolin was decreased by KCl concentrations above 50 mM, histones (H1, H2B and H3) were able to bind to the nucleolin in the presence of up to 300 mM KCl. A distinct difference between H1 and other histones was found in that H1 could produce p60 from nucleolin in both Nu-1 and Nu-2, whereas H2B and H3 stimulated the degradation of nucleolin to p60 only when Nu-2 was used for the source of nucleolin. A possible relationship between p60 formation and rRNA synthesis is discussed, but its exact role remains to be studied.

Animals↗

PubMed1993

A common T-cell epitope between human thyroglobulin and human thyroid peroxidase is related to murine experimental autoimmune thyroiditis.

We have investigated functional common T-cell epitopes between human thyroglobulin (hTg) and human thyroid peroxidase (hTPO) in mice. Four hTg peptides, Tg-P1, Tg-P2, Tg-P3 and Tg-P4, in which 5 amino acid residues are identical to those of hTPO, and 1 hTPO peptide, TPO-P4 relevant to Tg-P4, were prepared. Among these peptides, only Tg-P4 (residues 2730-2743) and TPO-P4 (residues 118-131) were highly antigenic and both peptides shared the common T-cell epitope. In addition, when the spleen cells from mice immunized with mouse Tg (mTg) were restimulated in vitro by Tg-P4 or TPO-P4 as well as by mTg, these cells transferred thyroiditis to naive recipient mice. These findings indicate that this common T-cell epitope between hTg and hTPO is immunogenic and related to the development of murine experimental autoimmune thyroiditis.

Amino Acid Sequence↗