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Biomedical subjects

M Usuda

Publications and source records attributed to M Usuda.

36 records · Page 2Linked to original sources

Infusion-free hemodiafiltration: simultaneous hemofiltration and dialysis with no need for infusion fluid.

A new simultaneous hemofiltration and dialysis system was developed which has no need of infusion fluid. The system employs two hemodiafilters in a direct series. An ultrafiltration rate and dialysate flow rate control system was employed to control the dialysate flow at the inlet and outlet, and the difference in volume was arranged to be the amount of water removed from the body. When the blood circuit was narrowed between the two hemodiafilters, the ultrafiltration was performed at the first hemodiafilter; at the second one, the dialysate moved to the blood side as a dilution fluid. To remove pyrogens and bacteria, tap water was subjected to activated charcoal, ion exchange and reverse osmosis treatment, followed by preparation of the dialysate. In clinical evaluation, this system showed marked improvement in clearance of middle and large molecules.

Adult↗

Effects of ticlopidine on thrombotic obstruction of A-V shunts and on dialysance of artificial kidneys.

Administration of ticlopidine, a new inhibitor of platelet aggregation, during hemodialysis to two patients with thrombotic occlusion of external A-V shunts markedly suppressed the obstruction of the shunt and improved anemia. Consequently, it was concluded that this drug may be useful for maintaining good blood flow and good patency of shunts in patients undergoing dialysis. In order to determine the dialyzer efficiency during dialysis, the reduction rate of the dialyzer was determined in vitro. The dialyzer reduction rates for urea, creatinine, uric acid, and phosphoric acid were all lowered after dialysis, and the administration of ticlopidine resulted in a suppression of the drop in the reduction rate. Based on the inhibitory effect of ticlopidine on platelet aggregation, it was assumed that a close correlation may exist between adhesion and aggregation of platelets and the drop in the efficiency of the dialyzer during dialysis as well as thrombotic obstruction of shunts.

Adult↗

Histological observations on some of the endocrine glands in the ironfish, with special regard to the hypophysis.

Endocrine glands of the ironfish were studied light microscopically to elucidate the relationship between the races of the genus Carassius. The rostral pars distalis of the adenohypophysis consists mainly of acidophils corresponding to prolactin cells and lead-hematoxylin positive cells corresponding to corticotrophs (ACTH cells). The prolactin cells are obviously arranged in the form of follicles. The proximal pars distalis contains orangenophils (STH cells) and two types of basophils (TSH and GTH cells). In the pars intermedia, three types of cells are identified: periodic acid Schiff positive cells, lead-hematoxylin stainable cells and orangenophils containing PAS positive coarse granules. In addition, small agranular cells are seldom demonstrated in the entire adenohypophysis. A considerable amount of aldehyde fuchsin positive neurosecretory material is laden in the cells of the nucleus preopticus and in the pars nervosa. The nucleus lateralis tuberis is composed of three portions: pars anterior, pars posterior, and pars lateralis. The thyroid follicles found in the pharyngeal region and head kidney show a mild state of activity. The interrenal cells intermingled with the chromaffin cells have a considerable amount of eosinophil cytoplasm. Judging from the gonadal condition, the breeding season of the ironfish may extend to the end of July.

Animals↗

A case of sarcoidosis associated with bronchial asthma.

A 54-year-old woman was treated for bronchial asthma for 14 yr. In March of 1989, chest roentgenography and computed tomography (CT) revealed development of bilateral pulmonary hilar lymph node enlargement. Positive 67Ga uptake was observed in bilateral pulmonary hili. Although levels of serum angiotensin converting enzyme (ACE) and lysozyme were within normal range, biopsy specimen of scalene lymph nodes showed noncaseating epitheloid-cell granuloma, leading to the diagnosis of sarcoidosis. Steroid therapy ameliorated both sarcoidosis and bronchial asthma. Although the association of sarcoidosis and bronchial asthma is uncommon, there may be an etiological relationship between them.

Asthma↗