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Biomedical subjects

H Kasahara

Publications and source records attributed to H Kasahara.

At least 19 recordsLinked to original sources

[MR study of the brain stem in elderly subjects].

Findings in patients in whom brain stem lesions were suspected were studied by a high-field-strength (1.5 T) MR imager. MR scans were obtained in 97 patients over a 10-month period. The mean age was 71 years (range, 39-94 years). A high incidence of infarction and lesions showing a high signal on T2-weighted image, but an almost normal signal on the T1-weighted image were observed at the pons in elderly cases. Furthermore, cases in which these two findings were observed, had a high incidence of lesion at other regions than pons. Cases with a past history of hypertension had higher incidence of lesions at the pons than normotensive patients (alpha less than 0.01). These findings suggest that MRI examination in the elderly could detect a high incidence abnormal lesions at the brain stem as well as in basal ganglia.

Aged

[Reconstruction of glomerular tufts--observation of mesangiolysis induced by anti-thymocyte serum].

The reconstruction process of the glomerular capillary structure following mesangiolysis induced in rats by anti-thymocyte serum (ATS) was investigated for three months. Cystic ballooning change of the glomerular tufts was remarkable four days after the administration of ATS, which was followed by inflammatory cell infiltration, and hypercellularity in mesangial area was observed one week later. Glomerular tufts were gradually reconstructed thereafter, leaving focal and segmental sclerotic or adhesive lesions. In the periphery of the ballooning area, a large vascular lumen was subdivided into smaller capillary lumina by endothelial and mesangial bridging, which resembled to the process in the fetal glomerulogenesis. The endothelial cells in mesangiolysis connected one another by junctional complexes and formed new capillary structure. The mesangial cells got in touch with the endothelial cells by mesangial bridging. In the proliferative lesion, endothelium-like cells could be recognized by immunostaining and had fenestrae with diaphragmatoid structure without mature basement membrane in the initial stage on electron microscopic observation. Interstitial-typed collagen fibers were found in the proliferative lesion, and they still existed in the focal segmental sclerotic lesion in the late stage of the experiment. The glomerular basement membrane (GBM) was seen to be reformed by fusing the original GBM with the newly synthesized one covering subendothelial space, where mesangial cells were interposed. Endothelial cells, endothelial-mesangial interaction and extracellular matrix formation seemed to play an important role in reconstruction of the glomerular tufts after mesangiolysis induced by ATS.

Animals

[Metabolic effects of GFX+BCAA solution in the old aged rats after operation].

Effects of total parenteral nutrition (TPN) on the perioperative metabolism in old aged rats were evaluated. Extremely old rats (over 100 weeks old) and young rats undergoing laparotomy were treated with TPN (200 ml/kg/days, 182 cal/kg/day, 148 nonprotein cal/N ratio) consisting of carbohydrate mixtures (combination of glucose, fructose, and xylitol, 4:2:1 GFX solution) and 10% amino acids solution with 30% of branched chain amino acids (BCAA). Blood, liver, and urine samples were analyzed on 1, 3 postoperative days. Increased body weight, positive balance in daily nitrogen excretion, and decreased water content of the liver were observed in old rats. Protein, glycogen, and triglyceride contents of the liver tissue increased in old rats. However the young rats showed negative nitrogen balance and stronger catabolic effect than the old rats. It suggested negative nutritional balance in young rats with this decreased dosage of GFX+BCAA solution suitable for the old rats. In conclusion, decreased amounts of GFX+BCAA solution improved perioperative metabolism in the extremely old.

Age Factors

Ultrastructure of matriceal changes in chronic phase of Masugi nephritis by quick-freezing and deep-etching method.

The three-dimensional ultrastructure of glomerular sclerosis in the chronic phase of Masugi nephritis was investigated using a quick-freezing and deep-etching method. Newly formed mesangial matrix, which was increased in the axial portions, was composed of fine fibrillar networks similar to those in the lamina densa of the basement membrane. These fibrils were 10-20 nm in diameter and directly attached to the cell membranes of mesangial cells, endothelial cells and podocytes by connecting fibrils. Moreover, thicker fibrils with diameters of 20-30 nm were present in the networks and were connected with cross-bridges. A newly formed matrix of fine fibrillar networks was also seen in the areas of mesangial interposition in the glomerular capillary wall. The border between the matrix and lamina densa was unclear. The fibrils organizing the networks of lamina densa of the glomerular loop were thickened, with some decoration. Connecting fibrils were disrupted in the areas of endothelial detachment. It is suggested that prolonged tissue injury with endothelial detachment might induce mesangial sclerosis composed of fine fibrillar networks. The increase in density of the networks seemingly interfere with the contractile function of mesangial cells, which is followed by alteration of mesangial flow.

Animals

Changes of serum bilirubin fraction in postoperative liver failure cases treated by plasmapheresis: an effective marker for evaluation of bilirubin removal.

Utility of a new method of bilirubin fractionation was evaluated in monitoring the effectiveness of plasma exchange (PE) performed in 10 postoperative cases with liver failure. Fractionation of serum bilirubin by high-performance liquid chromatography demonstrated a higher delta bilirubin (B delta) peak against lower conjugated bilirubin peaks [monoconjugated bilirubin (MCB) and diconjugated bilirubin (DCB)] in the three recovered cases. The calculated ratio of MCB/B delta and the ratio of B delta/(MCB + DCB + B delta) in the recovered cases showed statistically significant different against seven unrecovered cases (p less than 0.01). These results suggest that the recovered cases had a different quality hyperbilirubinemia and a different disease entity before PE as well as a different response to PE, and this novel method for serum bilirubin subfraction is considered a useful marker in selecting a patient responsive to PE.

Aged

[A case of renovascular hypertension with nephrotic syndrome, accompanied by focal segmental glomerulosclerosis-like lesion in the contralateral kidney].

A 66-year-old male patient of renovascular hypertension with nephrotic syndrome was described. Besides, focal segmental glomerulosclerosis like lesion was accompanied in the contralateral kidney. On admission, his blood-pressure amounted to 220/140 mmHg. Laboratory investigation included; urinary protein 10.5 g/day, serum creatinine 1.8 mg/dl, creatinine clearance 71.4/day, plasma renin activity 10.0 ng/ml/hr, angiotensin I 890 pg/ml and angiotensin II 40.0 pg/ml. Renogram and renal scintigram showed non-functioning pattern of left kidney. Arteriography disclosed approximately more than 95% stenosis of left main artery. Administration was discontinued because of poor control both in blood pressure and in proteinuria. After the left nephrectomy, the former normalized and the latter decreased. Microscopic examination of the right kidney revealed focal segmental glomerulosclerosis like lesion. So far as we know, this report is the first designed to elucidate renovascular hypertension with nephrotic syndrome accompanied by focal segmental glomerulosclerosis like lesion. The relationship between renovascular hypertension and nephrotic syndrome, and microscopic findings has been briefly discussed. It is suggested that the etiology of focal segmental glomerulosclerosis like lesion may be based on compensatory glomerular hyperfiltration caused by renovascular hypertension.

Aged

Mental aging and its medico-psycho-social background in the very old Japanese.

By clinical observations of 115 centenarians and 742 nonagenarians, the actual state of mental aging of the very old Japanese and some factors relating to it are shown in this paper. A great difference in psychophysical functions was found between the centenarians and the nonagenarians. Most centenarians manifested a distinct decline in these functions, while a decline was less prominent in the 90-year-olds. There was a significant relationship between mental and physical functions. Those manifesting a prominent decline in intellectual ability showed more frequent reduction in physical ability as well, and vice versa. The degree of their intellectual ability was also related to the following factors: their sex, academic and occupational careers, some types of personality traits and personality changes. The mental decline was less prominent in males, in the educated and in those with a syntonic personality than in others.

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