Biomedical subjects
Publications and source records attributed to Y Fujiki.
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Relationships between renal haemodynamics and the renin-angiotensin system were examined in 128 male adolescents with differing predispositions to hypertension. Baseline renal vascular resistance (RVR) was significantly elevated in the normotensive subjects with a positive family history, NT (FH+) group, than in the normotensives with a negative family history, NT (FH-) group, while there were no significant differences in other characteristics between the two groups. The borderline hypertensive subjects with a positive family history, BH (FH+) group, showed an even bigger increase in RVR and also had elevated plasma renin activity (PRA). In the NT (FH+) and BH (FH+) groups RVR correlated significantly with PRA levels. When captopril was given, the increased RVR in the NT (FH+) and BH (FH+) groups decreased, in correlation with baseline PRA, to levels not significantly different from those in the NT (FH-) group, in which no significant changes occurred in RVR. These results suggest that RVR may increase primarily in adolescents genetically predisposed to essential hypertension and that the renin-angiotensin system may play an important role in the mechanism of this increase in RVR.
To achieve a systematic synthesis of purine 8,5'-imino and substituted imino cyclonucleosides, 2',3'-O-isopropylidene-purinenucleosides substituted with a methylamino (4a,b), benzyl-amino (4c,d,g and h) and allylamino group (4e,f,i and j) at the C8 were synthesized. With these substrates in hand, extensive 8,5'-cyclization reactions were carried out using diphenyl carbonate/Et3N (Method A), N,N'-carbonyldiimidazole (Method B) and the Mitsunobu reaction (Method C) to give 8,5'-substituted imino cyclonucleosides (5a,c,d,e,f and g). The yields of cyclization by Method C are generally higher than by the other two methods. 5a, b,c,d,e,f,g and h were deprotected to the corresponding mother compounds 8 through one or two steps. In guanosine series, a new cyclic system comprising an 8,5'-carbamate ester bridge (6a-c) has been introduced.
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A 67-year-old woman was hospitalized with fever and jaundice. She immediately received PTCD because of obstructive jaundice. Hypotonic duodenography and endoscopic examination revealed a protuberance with an irregular surface at the site corresponding to the papilla Vateri. No evidence of malignancy was obtained from biopsied specimens of the lesion. Pancreatoduodenectomy was successfully performed. Histological examination of the resected specimen disclosed villous adenoma containing adenocarcinoma. The problems of histopathogenesis of cancer in adenoma arising in this particular region are discussed and the necessity of pancreatoduodenectomy in this particular neoplasma is emphasized.
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The appearance of nutrient canals in the mandibular anterior region was studied by evaluating the complete-mouth dental radiographs of 1,586 patients who were subdivided into four groups. The incidence of nutrient canals was very high in patients with periodontal disease, in patients of advanced age, and especially in endentulous patients. Nutrient canals appeared most frequently in radiographs demonstrating "above average" bone density with small diminutive trabecular spaces. Other factors influencing the presence of nutrient canals included the thickness of the alveolar bone, the quality of both cortical and cancellous bone, and the loss of mandibular teeth.
Membranes were isolated from highly purified peroxisomes, mitochondria, and rough and smooth microsomes of rat liver by the one-step Na2CO3 procedure described in the accompanying paper (1982, J. Cell Biol. 93:97-102). The polypeptide compositions of these membranes were determined by SDS PAGE and found to be greatly dissimilar. The peroxisomal membrane contains 12% of the peroxisomal protein and consists of three major polypeptides (21,700, 67,700 and 69,700 daltons) as well as some minor polypeptides. The major peroxisomal membrane proteins as well as most of the minor ones are absent from the endoplasmic reticulum (ER). Conversely, most ER proteins are absent from peroxisomes. By electron microscopy, purified peroxisomal membranes are approximately 6.8 nm thick and have a typical trilaminar appearance. The phospholipid/protein ratio of peroxisomal membranes is approximately 200 nmol/mg; the principal phospholipids are phosphatidyl choline and phosphatidyl ethanolamine as in ER and mitochondrial membranes. In contrast to the mitochondria, peroxisomal membranes contain no cardiolipin. All the membranes investigated contain a polypeptide band with a molecular mass of approximately 15,000 daltons. Whether this represents an exceptional common membrane protein or a coincidence is unknown. The implications of these results for the biogenesis of peroxisomes are discussed.
A rapid and simple method for the isolation of membranes from subcellular organelles is described. The procedure consists of diluting the organelles in ice-cold 100 mM Na2CO3 followed by centrifugation to pellet the membranes. Closed vesicles are converted to open membrane sheets, and content proteins and peripheral membrane proteins are released in soluble form. Here we document the method by applying it to various subfractions of a rat liver microsomal fraction, prepared by continuous density gradient centrifugation according to Beaufay et al. (1974, J. Cell Biol. 61:213-231). The results confirm and extend those of previous investigators on the distribution of enzymes and proteins among the membranes of the smooth and rough endoplasmic reticulum. In the accompanying paper (1982, J. Cell Biol. 93:103-110) the procedure is applied to peroxisomes and mitochondria.
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Human follicle-stimulating hormone (FSH) was digested with subtilisin, thermolysin, cyanogen gromide, pronase and trypsin to isolate the cystine-containing peptides. These peptides were purified by gel filtration through Sephadex G-50 column and by high-voltage paper electrophoresis at pH 6, 3.5 and/or 2. The location of the cystine-containing peptides in human FSH alpha- and beta-subunits was established by amino acid composition, end-group analysis and determination of the amino acid sequence by Edman degradation. The results indicate that the disulfide bonds are present between half-cystine residues located between positions 7 and 10, 28 and 87 and 82 and 84 in the alpha-subunit, and between positions 3 and 28, 17 and 51 and 32 and 104 in the beta-subunit of human FSH.