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Biomedical subjects

K Yoshioka

Publications and source records attributed to K Yoshioka.

At least 271 records · Page 15Linked to original sources
PubMed1995

Nitric oxide enhancement of erythropoietin production in the isolated perfused rat kidney.

We have previously reported that nitric oxide (NO) and guanosine 3',5'-cyclic monophosphate (cGMP) may be involved in the regulation of erythropoietin (Epo) production in response to hypoxia both in vivo and in vitro (20). In the present studies, we have used the isolated perfused rat kidney to assess the role of NO in oxygen sensing and Epo production. When arterial PO2 was reduced from 100 mmHg (normoxemic) to 30 mmHg (hypoxemic) in the perfusate of this system, perfusate levels of Epo were significantly increased. This hypoxia-induced increase in Epo production was significantly decreased by the addition of NG-nitro-L-arginine methyl ester (L-NAME; 1 mM) to the perfusates. Hypoxemic perfusion also produced a significant increase, and L-NAME significantly inhibited this increase, in intracellular cGMP levels in the kidney when compared with normoxemic perfused kidneys. Quantitative reverse transcription-polymerase chain reaction also revealed that hypoxemic perfusion produced significant increases in Epo mRNA levels in the kidney, which was blocked by L-NAME. Our findings further support an important role for the NO/cGMP system in hypoxic regulation of Epo production.

Animals↗
PubMed1995

Multiple pleural tuberculomas associated with a cold abscess of the hip.

We report an unusual case of multiple pleural tuberculomas associated with a cold abscess of the hip. A 26-year-old man was admitted because of diffuse nodular thickening of the right pleura and an abscess of the left hip. Biopsies of the pleura and abscess of the left hip revealed tuberculosis. Antituberculous chemotherapy for 12 months improved both the pleural tuberculomas and the cold abscess of the left hip.

Abscess↗
PubMed1995

Comparative distribution of the alpha 1(IV), alpha 5(IV), and alpha 6(IV) collagen chains in normal human adult and fetal tissues and in kidneys from X-linked Alport syndrome patients.

We have shown previously that the 5' ends of the genes for the alpha 5(IV) and alpha 6(IV) collagen chains lie head-to-head on Xq22 and are deleted in patients with Alport syndrome (AS)-associated diffuse leiomyomatosis. In this study, we raised a rabbit anti-human alpha 6(IV)chain antibody, demonstrated its specificity by the analysis of recombinant NC1 domains af all six type IV chains, and studied the distribution of the alpha 6(IV) chain in relation to the alpha 1(IV) and alpha 5(IV) chains in human adult and fetal tissues involved in AS and diffuse leiomyomatosis. The alpha 6(IV) chain colocalizes with the alpha 5(IV) chain in basement membranes (BMs) of many tissues, but not in glomerular BM. These data exclude the alpha 6(IV) chain as a site for AS mutations. The head-to-head genomic pairing of the alpha 5(IV) and alpha 6 (IV) genes implies coordinate transcription of the two genes. Differential localization of the alpha 5(IV) and alpha 6(IV) chains shows that the two chains are not always coordinately regulated. The alpha 6(IV) chain, together with the alpha 3(IV)-alpha 5(IV) chains, was absent from all renal BMs in eight patients with X-linked AS while the alpha 1(IV) and alpha 2(IV) chains were increased. The data support the existence of two independent collagen networks, one for the alpha 3(IV)-alpha 6(IV) chains and one for the alpha 1(IV) and alpha 2(IV) chains.

Adult↗
PubMed1995

Application of anti-bovine CD2 monoclonal antibody to the rosette inhibition test for detection of early pregnancy factor in cattle.

To reliably detect early pregnancy factor (EPF) in cattle, monoclonal antibody specific for bovine CD2 molecule, which is the sheep red blood cell (SRBC) receptor on bovine T cell surface, was applied to the rosette inhibition test. The rosette inhibition titers (RITs) were significantly higher in pooled sera from early pregnant cattle than in those of non-pregnant cattle using two anti-bovine CD2 monoclonal antibodies, B26A4 (P < 0.001) and BAQ95A (P < 0.01). The dissociation value of RITs between pregnancy and non-pregnancy with B26A4 was greater than that with BAQ95A. The B26A4 monoclonal antibody was therefore applied to the rosette inhibition test in subsequent experiments. The RITs in serum of individual pregnant and non-pregnant cows 8 days after estrus were significantly different (P < 0.001) by three or more dilutions. When the rosette inhibition test was carried out in sera from individual pregnant and non-pregnant cows at estrus and at 24, 72 and 168 hr after ovulation, the RITs of pregnancy sera increased significantly at 24 hr after ovulation as compared with non-pregnancy sera (P < 0.001). These results indicate anti-bovine CD2 monoclonal antibody can be utilized with the rosette inhibition test to detect EPF in cattle, and that this assay detects bovine EPF for pregnancy serum at least 24 hr after ovulation.

Animals↗
PubMed1995

[A surgically treated case of ventrally exophytic pontine glioma].

A surgically treated case of ventrally exophytic pontine glioma is reported. A 49-year-old woman, complaining of dysarthria, dysphagia and gait disturbance, was admitted to our department. Her past history included bronchial asthma. Plain skull x-p and tomography revealed destruction of the dorsum sellae and upper clivus. CT demonstrated an enhanced oval mass at the ventral side of the upper brainstem. The mass was severely compressing the brainstem dorsally. MRI revealed a low-intensity band between the tumor and the brainstem. Dynamic MRI demonstrated a pattern of rapid increasing and slow reduction. Cerebral angiogram demonstrated a paradoxical sign that pontine branches were located anterior to the basilar artery. The finding demonstrated that the tumor was an intraaxial mass. The first operation was performed by the orbitofrontomalar approach. On the trans-sylvian route, the tumor was removed partially with CUSA and neuronavigation system. Its histology was astrocytoma grade III. Radiation therapy was added. The patient's symptoms aggravated again. On the second operation, the transtemporal route with tentorial resection was chosen. Under a wide visual field, intracapsular subtotal resection of the tumor was performed. Interferon therapy was added. She was discharged to her home with no neurological deficits. Ventrally exophytic pontine glioma is very rare. Low-intensity band of MRI, a sign of extraaxial mass, was visualised in our case. On the other hand, cerebral angiogram demonstrated a paradoxical sign. This sign suggested that the tumor originated from the brainstem. With update skull base surgery and neuronavigation system, surgical therapy of ventrally exophytic pontine glioma is safe and effective.

Brain Neoplasms↗
PubMed1995

[Identical male twins showing progression from hypertrophic cardiomyopathy to dilated cardiomyopathy-like features].

Twenty-three-year-old identical male twins with hypertrophic cardiomyopathy which progressed into the dilated phase are reported. The younger brothers first presented at age 16 with an abnormal electrocardiogram. Hypertrophic nonobstructive cardiomyopathy with an asymmetric septal hypertrophy was diagnosed. He was treated with beta-blocker, but he stopped taking the drug as he had no symptoms at that time. He presented again at age 21 years with symptoms of apparent congestive heart failure. Echocardiography showed marked dilatation of the left ventricle with thin wall which was compatible with dilated cardiomyopathy. The elder brother presented with an initial echocardiogram showing systolic anterior movement of the mitral valve without asymmetric septal hypertrophy. He presented again with his brother aged 21 years when his echocardiogram showed slight dilatation of the left ventricle, although he did not complain of cardiac symptoms. These identical twins are the first reported cases of hypertrophic cardiomyopathy progressing to the deteriorated dilated phase.

Adult↗
PubMed1995

[Immunological and non-immunological mechanisms of tubulo-interstitial nephropathies].

Studies in experimental models and human cases provide compelling evidence for immune mechanisms of tubulo-interstitial nephropathy (TIN) or tubulo-interstitial nephritis. Analogous to immune-mediated glomerular injuries, anti-tubular basement membrane antibodies, immune complex deposition, antibodies with cell-surface antigens and cell-mediated reactions may contribute to the initiation and progression of TIN. Recent studies further indicate that local expression of cytokines, growth factors and adhesion molecules along with activation of tubular epithelial cells and fibroblasts participates in the inflammation and fibrogenesis in the renal interstitium. This process may also occur secondarily to primary glomerulonephritis, in which the tubulo-interstitial injury is suggested to be closely associated with the decline in renal function.

Animals↗
PubMed1995

[A case of hemorrhagic mixed cerebrovascular malformation of the brainstem draining through a transpontine vein].

A case of mixed cerebrovascular malformation of the brainstem with pontine hemorrhage is reported. The mixed cerebrovascular malformation was composed of medullary venous malformation, one hemorrhagic and another non-hemorrhagic mass. The latter masses were thought to be cavernous venous malformations by their MR findings. The medullary venous malformation drained to the anterior pontomesencephalic vein through a transpontine vein. A 70-year-old man, complaining of aggravation of left hemiparesis, was admitted to our department. His past history included traumatic cervical myelopathy and diabetic neuropathy. CT revealed a pontine hemorrhage with linear enhancement. Depending on MRI findings, the hemorrhage was thought to be an intratumoral hemorrhage within the cavernous venous malformation. Cerebral angiogram demonstrated medullary venous malformation. The malformation drained to the anterior pontomesencephalic vein through a transpontine vein. The linear enhancement was the transpontine vein itself. Medullary venous malformations in the brainstem are rare. With MRI, the transpontine vein is thought to be a characteristic feature of medullary venous malformation of the brainstem. We suggest that most cases of hemorrhagic medullary venous malformations are mixed cerebrovascular malformations. We emphasize the need for precise examination of other types of vascular lesions coexisting with medullary venous malformations.

Aged↗
PubMed1995

[A case of complex brain anomaly with arachnoid cyst treated well by cyst-cisternal shunt].

A rare case of complex anomaly, composed of schizencephaly, polymicrogyria, heterotopic gray matter, agenesis of the septum pellicidi and arachnoid cyst at the right middle cranial fossa was encountered. A 38-year old man, complaining of epileptic seizure, was admitted to our department. His past history included cerebral palsy. Plain skull roentgenogram showed protrusion of the right temporal bone and thinning of the ipsilateral sphenoidal wing. CT revealed arachnoid cyst and parietal crest surrounded by cortical layer on the right side. MRI also demonstrated the arachnoid cyst, parietal crest and agenesis of septum pellicidi. MRI, especially proton density weighted image, well demonstrated cortical layer surrounding the parietal crest, right opercular polymicrogyria and left heterotopic gray matter. The crest was diagnosed as schizencephaly. The arachnoid cyst was treated by cyst-cisternal shunt with a silicone tube (Sapporo shunt) after fenestrating the cyst. The tube was inserted into the sylvian fissure from the cyst and sutured to the inner wall of the cyst. Despite slight intratumoral hemorrhage in the CT at 1.5 months after the operation, the cyst markedly decreased in size. As to the diagnosis of the brain anomaly, MRI gives extremely useful information. Particularly for the diagnosis of anomalies of migration of neuronal cells, MRI, especially proton density weighted image, has been regarded as an indispensable examination. In the operation of subarachnoid cyst, to maintain the flow between the inside of its cyst and the basal cistern, cyst-cisternal shunt with a silicone tube had satisfactory results.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Human IgA nephritis: immunocytochemical evidence of a chronic inflammatory proliferative disorder.

This overview summarizes recent information concerning the biopathology of mesangial cell proliferation and matrix expansion which constitute fundamental features in human IgA nephritis. The currently available knowledge, mainly stemming for immunohistochemical observation of human materials, experimental investigations with laboratory animals, and mesangial cell culture studies, emphasizes the importance of cell to cell, cell to soluble factors, and cell to matrix interactions. Mesangial cells, activated by cytokines and growth factors, express adhesion molecules, stimulate proliferation both of themselves and neighbouring cells, and synthesize extracellular matrix. Matrix components, in turn, may influence the behaviour and proliferation activity of mesangial cells, or act as a receptor or reservoir for growth factors. Expression of protooncogenes, regulating cell proliferation and apoptosis, by glomerular cells could be associated with persistent cell replication and chronic tissue damage. These disease processes seem to be common to a group of diseases termed chronic inflammatory proliferative disorders.

Apoptosis↗
PubMed1994

Measurements of urinary adipic acid and suberic acid using high-performance liquid chromatography.

A sensitive and specific method was developed for measuring medium-chain dicarboxylic acids (adipic and suberic acid) in urine. These acids were extracted from urine with diethyl ether and converted into fluorescent derivatives with 9-anthryldiazomethane, which can be separated by high-performance liquid chromatography. The reproducibility was high and the recovery from urine was above 90%. Urinary concentrations of adipic acid in streptozotocin-induced diabetic rats were significantly higher than those in control rats. In diabetic patients, both adipic acid and suberic acid tended to be high, but not significantly. This method should be useful for measuring dicarboxylic acids in urine.

Adipates↗
PubMed1994

Dystrophin and dystrophin-related protein in the brains of normal and mdx mice.

To clarify the localization and characterization of dystrophin and dystrophin-related protein (DRP) in the brains of normal and mdx mice, we carried out immunostaining and immunoblotting studies using four region-specific antidystrophin and anti-DRP antibodies. With immunostaining, punctate immunoreactivity of dystrophin was seen along the cell bodies and dendrites of the cerebral cortical neurons in the normal mice. By contrast, dystrophin was not detected at all in the brains of mdx mice. Immunoreactivity of DRP was observed in the vascular walls, pia mater, and choroid plexus of both normal and mdx brains, but not in the neuronal cells. The possible compensatory increase of DRP as seen in the skeletal muscles of mdx mice was not noted in the brains. The immunoblot findings were very consistent with those of immunostain. Although further studies of brain-type dystrophin are necessary, it seems unlikely that DRP participates in any physiological function of the neuronal cells.

Animals↗
PubMed1994

Cellular localization of inflammatory cytokines in human glomerulonephritis.

We evaluated the expression of inflammatory cytokines in renal tissues obtained from 45 patients with several types of glomerulonephritis. Immunofluorescence studies with specific antibodies to interleukin (IL)-1 alpha, IL-1 beta, IL-6, tumour necrosis factor (TNF)-alpha, and TNF-beta showed intense cytoplasmic staining in the glomeruli and interstitium. Cells positive for these cytokines were found frequently in tissue from patients with lupus nephritis (WHO Class IV) and membranoproliferative glomerulonephritis, and, to a lesser extent, in tissue from patients with mesangial proliferative glomerulonephritis, Henoch-Schönlein purpura nephritis, and minimal change nephrotic syndrome. Most of these cells were dual-stained with a monoclonal antibody to monocytes-macrophages. In situ hybridization for cytokine mRNA, combined with immunoperoxidase staining for monocytes-macrophages, detected IL-1 alpha, IL-6, and TNF-alpha mRNA in monocytes-macrophages infiltrating the glomeruli and interstitium. Occasionally, there was weak or moderate immunostaining for IL-1 alpha, IL-6, and TNF-alpha in the glomerular mesangial and epithelial cells, but in situ hybridization signals were rarely found in these loci. These findings suggest that infiltrating monocytes-macrophages, rather than resident glomerular cells, are the major source of inflammatory cytokines in human glomerulonephritis.

Glomerulonephritis↗
PubMed1994

Immunoreactivity of the JK-132 monoclonal antibody directed against basement membrane collagen in normal and diabetic glomeruli.

The possible involvement of basement membrane-associated collagen (recognized by the monoclonal antibody JK-132) in the evolution of diabetic nephropathy was studied in kidney specimens from seven patients with noninsulin-dependent diabetes mellitus, and its distribution was compared with those of antibodies against alpha 1 to alpha 4 chains of type IV collagen. JK-132, a monoclonal antibody against basement membrane-associated collagen, reacted immunohistochemically exclusively with the mesangial matrix of the glomerular capillary. In contrast, antibodies to the alpha 1 and alpha 2 chains (IV) reacted strongly with mesangial matrix, and less strongly with the glomerular basement membrane (GBM). Antibodies to the alpha 3 and alpha 4 chains (IV) reacted mainly with GBM. In diabetes, JK-132 reacted most extensively with the expanded mesangial matrix, its staining intensity increasing with progression of the diabetic glomerulosclerosis. Antibodies to the alpha 1 and alpha 2 chains (IV) reacted prominently with the expanded mesangial matrix but less strongly with the GBM. Antibodies to the alpha 3 and alpha 4 chains reacted intensely with the thickened GBM. These results suggest that basement membrane-associated collagen differs from alpha 1 to alpha 4 chains of type IV collagen and that basement membrane-associated collagen is a good marker of mesangial expansion in diabetic nephropathy.

Aged↗
PubMed1994

Dystrophin and dystrophin-related protein in the central nervous system of normal controls and Duchenne muscular dystrophy.

To clarify the localization and characterization of dystrophin and dystrophin-related protein (DRP) in the human central nervous system (CNS), we carried out immunoblotting and immunostaining studies using three region-specific anti-dystrophin and one anti-DRP antibodies. With immunostaining, punctuate immuno-reactivity of dystrophin was seen along the cell bodies and dendrites of the cerebral cortical neurons and cerebellar Purkinje cells in the normal controls autopsied. By contrast, dystrophin was not detected at all in the CNS of Duchenne muscular dystrophy (DMD) patients with intellectual disturbance. Immunoreactivity of DRP was observed in the vascular walls of both normal and DMD brains, but not in the neuronal cells. Compensatory increase of DRP was not noted in DMD brains. This study suggests that in DMD the brain-type dystrophin originally present in neurons is absent and may be related to the intellectual disturbance.

Adolescent↗
PubMed1994

Hepatitis C virus genotypes are not responsible for development of serious liver disease.

Although hepatitis C virus (HCV) is known to have at least four kinds of genotypes, no clear relationship has yet been established between the genotype and the severity of liver disease. Therefore, we determined HCV genotypes in sera of 251 Japanese patients with type C chronic liver disease, using polymerase chain reactions with six independent primers. One set of primers and a probe derived from 5'-noncoding region of HC-J1 was supposed to detect all four genotypes, while the other five were devised to detect each of the genotypes. Among the patients, the major genotype was type II (69%) and the second most common was type III (18%). Type IV was found in 7%, while none had type I genotype. There was no significant difference in the distribution of any genotype among different stages of liver disease, although the ratio of type II to type III tended to be higher in the group of cirrhosis and hepatocellular carcinoma than in the chronic hepatitis group (5.5 vs 3.0). The amounts of HCV RNA were significantly greater in patients with type II (P < 0.001) compared with those with types III and IV. However, HCV concentrations of each genotype were not associated with the disease status. These results suggest that HCV genotypes are unlikely to be responsible for the development of more serious liver disease.

Adult↗