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Biomedical subjects

H Koide

Publications and source records attributed to H Koide.

At least 217 records · Page 12Linked to original sources
PubMed1991

Characteristic changes on brain CT in a case of Leigh encephalopathy with deficiency of pyruvate dehydrogenase.

A girl aged 23 months of Leigh encephalopathy with pyruvate dehydrogenase complex (PDHC) deficiency was reported. Brain CT scan showed atrophy of the frontal and parietal cortex, low density in the midbrain and putamina, and rounded caudatum. CT change was showed from rounded to atrophic caudatum during a three-month period. The rounded caudatum may be an early CT finding in Leigh encephalopathy.

Brain↗
PubMed1991

Proto-oncogene expression in peripheral blood mononuclear cells in IgA nephropathy.

We have investigated the expression of proto-oncogenes in mononuclear cells obtained from patients with IgA nephropathy using a RNA hybridization technique. Patients with IgA nephropathy expressed more c-myc, c-raf, c-fos, and c-jun proto-oncogene RNA than did normal controls. However, no significant expression of c-N-ras, c-mos or c-myb genes was found in the mononuclear cells of these patients. When the amount of urinary protein excretion was used as an indicator of disease activity (greater than 1 g/day), a positive correlation was found between c-myc, c-raf, c-fos, and c-jun expression and urinary protein excretion (P less than 0.01). The expression of these genes correlated also with the serum IgA concentration (P less than 0.01), IgA immune complex (P less than 0.01), and histopathological changes in renal tissues obtained from patients with IgA nephropathy (P less than 0.01). The results of this survey suggest that abnormally regulated proto-oncogene expression in mononuclear cells may play an important role in the progression of IgA nephropathy and may be useful as an indicator of disease activity and/or prognosis.

Adolescent↗
PubMed1991

Effects of methylprednisolone on glomerular and medullary mRNA levels for extracellular matrices in puromycin aminonucleoside nephrosis.

We examined the effects of methylprednisolone (MPSL) on type IV collagen, laminin and heparan sulfate proteoglycan (HSPG) mRNA levels in the renal glomeruli and medulla of puromycin aminonucleoside (PAN) nephrosis. mRNA levels encoding for type IV collagen and laminin increased markedly, whereas those for HSPG decreased significantly in glomeruli of PAN nephrosis. Administration of MPSL partially ameliorated the abnormal gene expression for basement membrane components. Furthermore, we showed that medullary mRNA levels for all these basement membrane components decreased with age in PAN nephrosis with or without MPSL treatment, suggesting that neither PAN nor MPSL has any effect on basement membrane component mRNA levels in the renal medulla. In contrast, mRNA levels for the interstitial collagens including alpha 1 (I) and alpha 1 (III) chains in glomeruli showed little change with or without MPSL treatment, whereas those in medulla increased significantly in PAN nephrosis when compared with the control. MPSL ameliorated the abnormal gene expression of alpha 1 (I) and alpha 1 (III) collagen in renal medulla. These results indicate that PAN affects both glomerular mRNA encoding for basement membrane components and medullary mRNA encoding for interstitial collagens, and that MPSL has marked effects on the amelioration of abnormal gene expression in both glomeruli and medulla of PAN nephrosis.

Animals↗
PubMed1991

Effects of dietary Ca2+ on erythrocyte Na(+)-transport systems in spontaneously hypertensive rats.

1. The purpose of this study was to determine the effect of dietary Ca2+ intake on blood pressure and erythrocyte Na+ transport in spontaneously hypertensive rats. 2. Spontaneously hypertensive rats and Wistar-Kyoto rats were fed diets with three different Ca2+ contents, 0.1% (low-Ca2+ diet), 0.6% (normal-Ca2+ diet) and 4.0% (high-Ca2+ diet), between 6 and 20 weeks of age. At 20 weeks of age, the levels of erythrocyte Na+ efflux, as well as Na+ and K+ contents in erythrocytes, were measured. 3. On the low-Ca2+ diet, spontaneously hypertensive rats showed an enhancement of hypertension. Conversely, on the high-Ca2+ diet, they showed an attenuation of the increase in blood pressure. Spontaneously hypertensive rats had a lower erythrocyte Na+ content and increased activity of the Na+ pump at higher levels of dietary Ca2+. Passive Na+ permeability and Na(+)-K+ co-transport were similar in spontaneously hypertensive rats on the low-, normal- and high-Ca2+ diets. There were no significant differences in blood pressure and in Na+ pump activity in WKY on the three different diets. 4. It is concluded that dietary Ca2+ might affect the regulation of blood pressure in spontaneously hypertensive rats by changing the activity of Na+ pump in the cell membrane.

Animals↗
PubMed1991

Increased expression of proliferating cell nuclear antigen mRNA in peripheral blood mononuclear cells from patients with IgA nephropathy.

Proliferating cell nuclear antigen (PCNA)/cyclin is an intranuclear polypeptide antigen whose appearance correlates with the proliferative state of cells. The authors investigated the expression of PCNA from peripheral blood mononuclear cells (PBMC) in 23 patients with IgA nephropathy and 10 healthy age-matched controls, using ribonucleic acid hybridization techniques. The majority of patients with IgA nephropathy (22 of 23 patients) showed elevated PCNA expression in PBMC, while no PCNA expression was detected in PBMC of normal controls. A positive correlation was noted between PCNA expression of PBMC and glomerular injuries and PCNA expression and urinary protein excretion. Sixty-three percent of patients with grade III and IV histological findings showed strong PCNA (more than ) expression in their PBMC. The urinary protein excretion in patients who showed more than ( ) PCNA expression was more than 2.5 g/d, while that in patients with less than (+) PCNA expression was less than 1.0 g/day. These findings indicate that abnormally regulated PCNA expression in PBMC may play an important role in the progression of IgA nephropathy, and that PCNA expression in PBMC may be a useful indicator of disease activity.

Adolescent↗
PubMed1991

Computer imaging analysis of the correlation between intensities of glomerular immune-deposits and histopathology in patients with IgA nephropathy.

The relationship between the intensities of IgA, C3c, and C9 deposition in renal glomeruli and the severity of histopathologic injuries in patients with IgA nephropathy was examined using Microscope-Photometer 01K and a computer. Percentages of glomerular adhesion to Bowman's capsules, crescent formation, and glomerular sclerosis were calculated in the renal specimens. There was a significant correlation between the intensity of each C3c and C9 deposition in glomeruli and the degree of glomerular adhesion to Bowman's capsules and crescent formation in patients with IgA nephropathy. There was no significant correlation between the intensity of C3c or C9 deposition in glomeruli and the degree of glomerular sclerosis. No relationship was found between the intensity of IgA deposition in glomeruli and the degree of histopathologic injuries. The patients with negative or trace amounts of glomerular C3c deposits showed less severe glomerular injuries. Thus, the intensity of C3c and C9 deposition in glomeruli appears to be one of the critical factors responsible for the active progression of glomerular inflammatory process in patients with IgA nephropathy.

Complement C3c↗
PubMed1991

Urinary levels of interleukin-6 and disease activity in patients with IgA nephropathy.

We studied, using ELISA, 27 patients with IgA nephropathy to determine if levels of urinary interleukin-6 (IL-6) might reflect the disease activity. The levels of urinary IL-6 in patients with the advanced stage were significantly higher than those in patients with the mild stage of the disease or in healthy adults. The results showed a significant correlation between the levels of urinary IL-6 and the disease activity, i.e., levels of urinary cast and urinary protein. It was thus suggested that the measurement of urinary IL-6 is useful in evaluating the degree of glomerular injuries and/or prognosis in patients with IgA nephropathy.

Adult↗
PubMed1991

Glomerular nonenzymatic glycosylation and lipid peroxide are increased in the early phase of streptozotocin-induced diabetic rats prior to major histopathologic alterations.

Levels of glomerular nonenzymatic glycosylation and lipid peroxide in streptozotocin (STZ)-induced diabetic rats were examined. Isolation of glomeruli was performed using a sieving technique. The levels of nonenzymatic glycosylation in the glomeruli of these rats were measured by the thiobarbituric acid (TBA) method. Measurement of lipid peroxide, i.e., malondialdehyde (MDA), levels in the renal cortex, medulla and isolated glomeruli was performed by the TBA test. Light-microscopic and immunofluorescent examinations were also performed. An increase in nonenzymatic glycosylation in the glomeruli was observed in the early phase, i.e., after 4 and 12 weeks, in STZ-induced diabetic rats. The levels of MDA in the renal cortex of 12-week-old STZ-induced diabetic rats were also significantly increased compared with those of control rats at the same age. Levels of MDA in the glomeruli of 12-week-old STZ-induced diabetic rats were slightly increased compared with those of control rats, but there was no statistical significance. In immunofluorescence, IgG or IgM was deposited in the glomerular mesangial areas and capillary walls in 12-week-old diabetic rats. However, there was no significant change in renal tissues after 4 and 12 weeks in STZ-induced diabetic rats. It was concluded that glomerular nonenzymatic glycosylation and lipid peroxide were already increased in the early phase of STZ-induced diabetic rats prior to the appearance of marked histologic alterations.

Animals↗
PubMed1991

Effects of dietary calcium on erythrocyte sodium ion transport systems in spontaneously hypertensive rats.

The alteration of sodium ion transport in red blood cells was observed in SHR and patients with essential hypertension. The purpose of the present study was to determine the effects of dietary calcium intake on blood pressure and sodium ion transport of red blood cells in SHR. The SHR were fed a diet with three different levels of calcium contents as follows: 0.1% (low), 0.6% (normal) and 4.0% (high) of calcium between 6 and 20 weeks of age. At 20 weeks of age, the levels of erythrocyte sodium efflux, sodium or potassium contents in the red blood cells were measured. On the high Ca diet, SHR showed an attenuation of the increase in blood pressure. On the low Ca diet, SHR showed an enhancement of hypertension. In proportion of increasing of dietary calcium contents, SHR had a lower level of sodium content in the RBC and a higher activity of the sodium pump. However, the passive sodium permeability and sodium-potassium cotransport in SHR were similar among the three different Ca diets. It is concluded that the amounts of dietary Ca might be related to the regulation of blood pressure by changing the sodium pump of the cell membrane in SHR.

Animals↗
PubMed1991

Adaptation of low-phosphate diet in renal brush borders of spontaneously hypertensive rats.

A LPD seems to increase the Pi uptake by vesicles of the BBM of the renal cortex. This study was done to find if there was adaptation to a LPD in the BBM vesicles from the superficial or deep cortex in SHR, with WKY rats as control. The fractional excretion of Pi of SHR on the LPD was higher than that of WKY rats (p less than 0.01). The Vmax of Pi uptake in BBM vesicles from superficial cortex of WKY rats on the LPD was greater (p less than 0.05) than in such rats on a diet with a normal level of phosphate. Thus, the adaptation to a LPD was normal in WKY rats. However, in BBM vesicles from the superficial cortex of SHR kidneys, the difference in this Vmax depending on diet was insignificant. In BBM vesicles of the deep cortex of SHR kidneys, this Vmax was higher (p less than 0.01) on the LPD. The apparent Km was not significantly different in different groups or parts of the renal cortex. These results suggest that BBM vesicles in the superficial cortex of SHR kidneys did not adapt to the LPD. The less adaptation in SHR in vivo indicates that there may be a defect in Pi transport in BBM vesicles of the superficial cortex of SHR kidneys.

Adaptation, Physiological↗
PubMed1991

Vitamin D metabolism in nephrotic rats.

It is well known that patients with nephrotic syndrome and normal renal function have hypocalcemia in spite of high PTH concentration, caused by the low serum concentration of the active vitamin D metabolite, 1,25(OH)2D, presumably due to its loss in urine. However, it has been uncertain whether the conversion of 25(OH)D into 1,25(OH)2D in the kidney is impaired. In this study, we examined the responsibility of 1,25(OH)2D in PAN-induced nephrotic rats. Sprague-Dawley rats weighing 250 g were given subcutaneous injections 1.5 mg/100 g PAN for 12 days prior to use. Some of these rats were given intraperitoneal injection of 100 IU of 25(OH)D3 for 3 days prior to use and of 10 IU of PTH. We measured Ca2+ in plasma, vitamin D metabolites and mid-molecule PTH in serum, renal 25(OH)D-1-hydroxylase activity in vitro, and response of nephrogenous cyclic AMP to exogenous PTH administration. In nephrotic rats, plasma Ca2+, serum 25(OH)D and 1,25(OH)2D were lower than in control rats, and the serum PTH level was higher than in controls. In 25(OH)D3-injected nephrotic rats, Ca2+ and 1,25(OH)2D were higher than in nephrotic rats, indicating that the decreased level of 1,25(OH)2D in nephrotic rats was partially due to the low serum level of 25(OH)D. Despite the elevation of the serum level of PTH, the Vmax of renal 25(OH)D-1-hydroxylase in nephrotic rats was lower than in controls. Response of nephrogenous cyclic AMP to PTH in nephrotic rats was lower than in controls. Although nephrotic rats had higher PTH levels than control rats, Vmax of renal 25(OH)D-1-hydroxylase and response of cyclic AMP to exogenous PTH administration in nephrotic rats were lower than in controls, suggesting that abnormalities of calcium metabolism in patients with nephrotic syndrome might be partially attributed to the impaired renal response to PTH.

25-Hydroxyvitamin D3 1-alpha-Hydroxylase↗
PubMed1991

[The relationship between cerebral white matter changes, mental function and blood pressure in normal elderly].

The authors examined the relationship between cerebral white matter changes and mental function, blood pressure in 39 neurologically normal aged (21 males, 18 females, mean age 75.0 years) who had no latent lesions on MRI images. The severity of cerebral white matter changes was estimated by T1 value images on MRI and was measured in the bilateral frontal lobe on an axial slice at the level of the basal ganglia and in the bilateral anterior, middle, and posterior portions on axial slices at the level of the body of the lateral ventricle. Mental function was measured by the Hasegawa's dementia rating scale (HDS) and Kohs' block design test (Kohs' test). The severity of cerebral frontal white matter changes increased significantly with age (p less than 0.05). However there was no significant correlation between the severity of cerebral white matter changes and HDS, Kohs' test. The severity of frontal white matter changes correlated with the mean arterial blood pressure (p less than 0.02). These results suggest that the severity of cerebral white matter changes is not related with mental function in the normal elderly, and that the severity of frontal white matter lesions is related with mean arterial blood pressure.

Adult↗
PubMed1991

Immunohistochemical studies of glomerular extracellular components in repeated renal biopsies of patients with IgA nephropathy.

Immunohistochemical and light microscopic examinations were carried out to assess the correlation between the progression of glomerular lesions and changes in the intensity of glomerular extracellular components such as type IV and I collagens, laminin and fibronectin, and of IgA deposits in repeated renal biopsies of patients with IgA nephropathy. By light microscopy, the percentage of glomeruli showing glomerular mesangial expansion or sclerosis was found to be significantly higher in the second renal biopsy. Type IV collagen, laminin and fibronectin were also marked in the expanded glomerular mesangium in the second biopsy. Although these components were not observed in the global sclerotic glomeruli, type I collagen was detected in such areas of patients with IgA nephropathy. Patients who revealed high percentages of glomerular sclerosis associated with marked type IV collagen, laminin, fibronectin and/or type I collagen, had high levels of proteinuria and progressive deterioration of renal function. It is concluded that hyperproduction of the above extracellular components mainly in the glomerular mesangium is closely linked to the progression of glomerular lesions in patients with IgA nephropathy.

Adolescent↗
PubMed1991

[Effect of aging on P300 in normal subjects].

The P300 component of the event-related brain potential (ERP) is generated when subjects discriminate stimulus events which differ from one another. There are many reports about the effect of age on P300 in clinically normal subjects. However, these subjects may include individuals with silent cerebral infarctions or abnormal periventricular hyperintensity (PVH) on MRI. In this study, we completely excluded such subjects using MRI and examined the effect of aging on P300. One hundred four neurologically normal subjects (mean age 58.6 years, 55 men, 49 women) who had no lesions or severe PVH on MRI were selected. An oddball stimulus paradigm was employed and ERPs were elicited by presenting a series of binaural 1000 (82%) and 2000Hz (18%) tones through headphones. Prolongation of P300 latency was significantly correlated with advancing age (p less than 0.001): P300 latency increased by approximately 1.7 msec per year of age, with a prominent increase after age 60. But there was no significant difference between males and females in P300 latency. The significant correlation between age and P300 amplitude was observed only at Pz (p less than 0.05). These results indicate that there is a gradual mental decline with aging in normal subjects without silent cerebral infarctions or PVH.

Adult↗