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Biomedical subjects

H Yajima

Publications and source records attributed to H Yajima.

At least 181 records · Page 10Linked to original sources
PubMed1988

Metachromatic leukodystrophy. Report of siblings with the juvenile type of metachromatic leukodystrophy.

Two sisters with juvenile metachromatic leukodystrophy are described. The patients were 17 and 20 years old. The younger sister died and an autopsy was performed. The elder sister keeps alive. A sural nerve biopsy of both cases revealed an accumulation of metachromatic lipid granules in the Schwann cells and macrophages. The autopsy also disclosed these granules especially in the brain, gallbladder, kidney and pancreas. A lipid analysis of the cerebral white matter showed sulfatide accumulation that was 1.5 times that of controls. Histochemically, the accumulated lipid was different in the brain from that in other organs. An electron microscopic examination of the accumulated metachromatic lipid granules showed various structures such as concentric lamellar, tuffstone, herringbone and hexagonal honeycomb appearances, and some ultrastructural differences between the nervous system and other organs.

Adolescent↗
PubMed1988

Structure-activity relationship of hylambatin and its fragments as studied in the guinea-pig ileum.

Hylambatin (Hyl), a dodecapeptide isolated from the skin of the African frog, Hylambates maculatus, belongs to the family of tachykinin or physalaemin-like peptides. Hylambatin and its 12 fragments were tested in the guinea-pig ileum preparation for contractile activities. All fragments except 3 had contractile activities. The C-terminal fragment as short as the octapeptide sequence was at least as active as the parent molecules. The heptapeptide fragment (Hyl6-12) and the hexapeptide fragment (Hyl7-12) were less active and the C-terminal pentapeptide fragment (Hyl8-12) and the N-terminal hexapeptide fragment (Hyl1-6) were much less active. The N-terminal pentapeptide fragment (Hyl1-5) and the N-terminal fragment from which the N-terminal Asp or Asp-Pro residues were removed (Hyl2-6, Hyl3-6), were inactive at doses used.

Animals↗
PubMed1988

Progression of the phenotype of transformed cells after growth stimulation of cells by a human papillomavirus type 16 gene function.

Alteration of the growth properties of the established murine fibroblast cell lines NIH 3T3 and 3Y1 was studied in monolayer cultures and in cells suspended in semisolid medium after introduction of a cloned human papillomavirus type 16 (HPV16) DNA. HPV 16 DNA stimulated both cell lines to grow beyond their saturation densities in monolayer cultures without any apparent morphological changes or tendency to pile up. These cells were also stimulated to grow in soft agar. Since essentially all the cells that received the viral gene were stimulated to grow, the growth-stimulatory activity of HPV16 appeared to be due to the direct effect of a viral gene function. The NIH 3T3 cells showed an additional change in growth properties upon prolonged incubation of dense monolayers of cells containing the HPV16 DNA; morphologically recognizable dense foci appeared at a frequency of about 10(-3). These cells, when cloned from the foci, grew more rapidly in soft agar than the parental cells and were morphologically transformed. In other words, there were two sequential steps in cell transformation induced by HPV16. Practically all the viral DNAs were present in the cells as large rearranged multimers and were integrated into host chromosomal DNA. There was no obvious difference in the state of viral DNA in the cells of the original clone or the three subclones derived from it as dense foci. There was no difference in the amount or the number of viral RNA species expressed in the cells at these two stages. The secondary changes in the growth properties of NIH 3T3 cells appear to be due to some cellular alterations.

Animals↗
PubMed1988

Effects of human pancreatic polypeptide on exocrine pancreatic function in conscious rats.

The effect of newly synthesized human pancreatic polypeptide (hPP) on pancreatic secretion stimulated by a diversion of bile-pancreatic juice (BPJ) from the intestine, and plasma hPP concentration were examined in conscious rats. Exogenous hPP infusion (1, 10 micrograms/kg/hr) inhibited pancreatic protein, bicarbonate and fluid outputs during BPJ diversion in a dose-dependent manner. During 1 and 10 micrograms/kg/hr hPP infusion plasma hPP immunoreactivity increased to 369 +/- 22.9 and 1,125 +/- 90.2 pg/ml, respectively. These results suggest that newly synthesized hPP has an inhibitory activity on exocrine function of the pancreas.

Animals↗
PubMed1987

Effect of synthetic neuromedin U-8 and U-25, novel peptides identified in porcine spinal cord, on splanchnic circulation in dogs.

Two novel peptides which exert a potent stimulant effect on rat uterus smooth muscle have recently been identified in porcine spinal cord. These peptides designated neuromedin U-8 and U-25 have been reported to exert a hypertensive effect in rats. But further biological activities are not known. In the present study, the effect of these peptides on blood flow in portal vein, superior mesenteric artery and pancreatic tissue and on blood pressure were examined in dogs, utilizing recently developed ultrasonic transit time volume flow meter and laser Doppler flow meter. Neuromedin Us potently reduced blood flow in superior mesenteric artery. The minimum reductions could be observed even at very small doses of neuromedin U-25 (32 fmol/kg) and U-8 (90 fmol/kg), while the maximal reductions of 48.4 and 51.0% were attained at the doses of 320 pmol/kg (U-25) and 900 pmol/kg (U-8), respectively. These peptides also reduced portal vein blood flow, and the maximal reductions of 42.1 and 37.2% were attained at the doses of 32 pmol/kg (U-25) and 90 pmol/kg (U-8), respectively. On the other hand, blood flow in pancreatic tissue increased slightly with the maximal increases of 13.8% at 3.2 pmol/kg (U-25) and 11.8% at 9 pmol/kg (U-8), respectively. The maximal increases of blood pressure were 5.2% at 320 pmol/kg (U-25) and 4.3% at 90 pmol/kg (U-8). Furthermore, neither neuromedin U-25 nor U-8 influenced the axillary artery blood flow, suggesting their selective effect on splanchnic blood flow. Because of the potent and probably selective activity on splanchnic circulation, neuromedin U-25 and U-8 may well be recognized as physiologically significant novel neuropeptides or hormones.

Animals↗