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Biomedical subjects

Y Sakamoto

Publications and source records attributed to Y Sakamoto.

At least 397 records · Page 22Linked to original sources
PubMed1993

[The influence of rush immunotherapy on the production of interleukin-5 from mononuclear cells].

We investigated the influence of rush immunotherapy (RI) on the production of interleukin (IL)-5 from peripheral blood mononuclear cells (PBMC) in asthmatics sensitive to Dermatophagoides farinae (Df). The levels of IL-5 produced varied among the subjects, and these levels were not affected by the addition of Df, regardless of RI. When IL5 levels were individually compared before and after RI, some cases demonstrated an apparent decrease in production at 16 weeks after RI. It is considered that further study will be needed to confirm whether or not immunotherapy can truly suppress the production of IL-5.

Adolescent↗
PubMed1992

Cross-linking of apolipoproteins is involved in a loss of the ligand activity of high density lipoprotein upon Cu(2+)-mediated oxidation.

A recent study demonstrated that Cu(2+)-mediated oxidation of high density lipoprotein (HDL) resulted in a loss of the capacity to reduce cholesterol from macrophage foam cells [(1991) Proc. Natl. Acad. Sci. USA 88, 6457-6461]. In the present study we characterized the physicochemical properties of oxidized HDL and correlated them with the ligand activity toward the HDL receptor. Among them, the cross-linking of apolipoproteins and an increase in lipid peroxides were characteristic and closely similar to those of tetranitromethane-treated HDL, an abortive ligand for the HDL receptor. Cellular experiments with murine peritoneal macrophages revealed that both the cellular binding activity of HDL and its capacity to enhance cholesterol efflux from macrophage foam cells were markedly reduced upon oxidation. These results suggest that cross-linking of HDL apolipoproteins is involved in the loss of the ligand activity of oxidized HDL.

Animals↗
PubMed1992

Alloalbuminemia in Sweden: structural study and phenotypic distribution of nine albumin variants.

Plasma samples exhibiting alloalbuminemia on electrophoresis at pH 8.6 were requested from clinical laboratories throughout Sweden. Nine variants, each representing a different single point mutation, were found in 100 apparently unrelated Swedes. The overall prevalence of alloalbuminemia was estimated at 1:1700. Mutations were identified by protein-structural analysis followed by allele-specific DNA hybridization to verify the most common types. Slightly retarded (+1) mobility was seen in 80 cases. Of these, 71 had the Arg(-2)----Cys proalbumin variant previously called Malmö I proalbumin. Thirteen examples of the second most frequent type, the substitution Lys313----Asn and a mobility change of -1 charge unit, were found, as well as six cases of Glu570----Lys (albumin B) and a single case of Arg-1----Gln (proalbumin Christchurch). Five previously unreported types of alloalbuminemia were identified: four instances of Glu376----Gln, which is the second known mutation at this site; two examples of Asp550----Ala, the second mutation reported at this site; and one example each of Asp63----Asn, Gln268----Arg, and Asn318----Lys. Other mutations were identified among eight subjects of foreign descent. The high frequency and relatively uniform geographic distribution of the Arg-2----Cys mutation suggest that it may have occurred in a founder individual many generation ago in Sweden.

Amino Acid Sequence↗
PubMed1992

Simultaneous localization of histamine and factor VIII-related antigen in the endothelium of the human umbilical vein.

Simultaneous immunoelectron microscopic localization of histamine and factor VIII-related antigen was examined on the same ultrathin section of the endothelium of the human umbilical vein from full-term deliveries by means of the double-immunolabeling technique. Small gold particles demonstrating antibody reaction with histamine are preferentially located in the cytoplasmic matrix and organelles, especially in mitochondria and on the luminal membrane surface of the endothelial cells. The gold particles representing histamine immunoreactivity also located on some of Weibel-Palade (WP) bodies. In contrast, large gold particles demonstrating factor VIII-related antigen are concentrated preferentially on most WP bodies. Single labeling of either histamine or factor VIII-related antigen shows similar results to those of the double labeling. The present study indicates that some WP bodies are involved in storage of both factor VIII-related antigen and histamine, but others store factor VIII-related antigen only. This difference in contents of WP bodies may be induced during the development and maturation process of this inclusion. At any rate, it is reasonable to consider that WP bodies have important roles in both vascular tonus and hemostasis during the vascular obliteration.

Cytoplasm↗
PubMed1992

Analysis of the flagellin (hag) gene of alkalophilic Bacillus sp. C-125.

Motility of the alkalophilic Bacillus sp. C-125, a flagellate bacterium, was demonstrated to be Na(+)- and pH-dependent. Flagellin protein from this strain was purified to homogeneity and the N-terminal sequence determined. Using the hag gene of Bacillus subtilis as a probe, the hag gene of Bacillus sp. C-125 was identified and cloned into Escherichia coli. Sequencing of this hag gene revealed that it encodes a protein of 272 amino acids (M(r) 29,995). The predicted N terminal sequence of this protein was identical to that determined by N-terminal sequencing of the flagellin protein from strain C-125. The alkalophilic Bacillus sp. C-125 flagellin shares homology with other known flagellins in both the N- and C-terminal regions. The middle portion, however, shows considerable differences, even from that of flagellin from the related species, B. subtilis.

Amino Acid Sequence↗
PubMed1992

Heterophile antigens in serous cystadenocarcinoma of the human ovary.

As the aberrance of carbohydrate moieties, the appearance of heterophile antigens in human ovarian cancer tissue was studied using various heterophile antigens and antibodies together with antisera raised in rabbits by immunization with extracts of human ovarian cancer tissues. In the immunodiffusion test, rabbit antisera reacted with a heat-stable, perchloric-acid extractable antigen that was different from CEA and CA125 and possessed Hanganutziu-Deicher (HD)-type specificity in all 4 specimens of serous cystadenocarcinoma of the ovary. Furthermore, a pathologic serum with strong HD-antibody complex formed a precipitin line with one of them. In the cancer tissue, we also immunochemically demonstrated the presence of rat-erythrocyte antigens. However, other types of heterophile antigens, such as Paul-Bunnell and Forssman, were not detected. These results suggest that HD-type antigens appear in serous cystadenocarcinoma of the human ovary, one in broad distribution and some in specific cases.

Animals↗
PubMed1992

Epinephrine augments cortisol secretion from isolated perfused adrenal glands of guinea pigs.

To determine direct effects of epinephrine on adrenal cortisol secretion, bilateral adrenal glands were isolated from guinea pigs, together with bilateral kidneys, aorta, and inferior caval vein for influent and effluent routes. The preparation was perfused with oxygenated Krebs-Ringer bicarbonate solution (pH 7.4) containing 10 mM glucose, 0.2% bovine serum albumin, and 4.6% dextran. The perfusate cortisol level was elevated by the addition of epinephrine in a dose-dependent manner at concentrations greater than 100 pg/ml and increased eightfold as high as the basal level at 1 micrograms/ml epinephrine. The stimulatory effect of epinephrine on cortisol secretion was completely abolished by phentolamine, an alpha-adrenergic antagonist but was not affected by propranolol, a beta-adrenergic antagonist. These results demonstrate that epinephrine has a direct stimulatory effect on adrenal cortisol secretion via an alpha-adrenergic mechanism and also suggest that not only adrenocorticotropin but also epinephrine is a most important factor for the regulation of cortisol secretion.

Adrenal Glands↗
PubMed1992

Reproducibility of data obtained by a newly developed anterior eye segment analysis system, EAS-1000.

The reproducibility of data obtained from the recently developed anterior eye segment analysis system (EAS-1000) was evaluated. 40 normal eyes and 62 cataractous eyes were examined at Kanazawa Medical University Hospital or Yayoi Hospital. The radius of the corneal curvature, the corneal thickness, anterior chamber depth, whole lens thickness, anterior chamber angle and the scattering light intensity were all observed on a slit section of the lens, and the intrapupillary area of the cataractous shadow was measured from a retroillumination image. The measurements were made twice at an interval of 14.2 days. There were no significant differences between the data of the 1st and 2nd examination in either place.

Adolescent↗
PubMed1992

In vivo observation of the axial movement of intraocular lenses through an anterior eye segment analysis system.

The small axial movement of the anterior surface of implanted intraocular lenses (IOLs) were examined in pseudophakic eyes with one-piece and three-piece IOLs using an anterior eye segment analysis system. The movement was calculated as the distance between the posterior surface of the cornea and the anterior surface of an IOL under a normal pupil size, following the instillation of 1% pilocarpine and 1% cyclopentolate solutions, respectively. The axial movement including movement after instillation of pilocarpine and cyclopentolate was 0.17 +/- 0.06, 0.05 +/- 0.07 and 0.13 +/- 0.06 mm, in phakic eyes and eyes with one-piece and three-piece IOLs, respectively. Image analysis techniques using Scheimpflug images proved its usefulness in the research field of IOL implantation.

Adolescent↗
PubMed1992

Quantitative evaluation of nuclear cataract using image analysis.

To quantitatively evaluate nuclear lens opacification, we applied image analysis techniques. Utilizing a newly developed anterior eye segment analysis system, Scheimpflug slit images were taken in 65 eyes with transparent lenses and 31 eyes with nuclear cataract. In transparent lenses, scattering light intensity of the anterior fetal nucleus (AFN) was equal to or less than that of the posterior fetal nucleus (PFN). In eyes with nuclear cataract, scattering light intensity of the AFN was higher than that of the PFN. Utilizing this phenomenon, nuclear opacification was evaluated by the difference of scattering light intensity between the AFN and PFN (delta i value). The methodology applied in this investigation provides precise grading of nuclear cataract and progression thereof.

Adult↗
PubMed1992

Relations between the averaged 13C nuclear magnetic resonance chemical shift and the carcinogenic activity of polycyclic aromatic hydrocarbons.

13C Nuclear magnetic resonance (13C-NMR) spectra were measured for polycyclic aromatic hydrocarbons (PAH) to examine the correlation between their chemical shift and carcinogenicity. We confirmed our previous proposition that the carcinogenicity of PAH molecules can be predicted from the value of the averaged 13C-NMR chemical shift. It was also found, using the averaged chemical shift as a parameter, that several quantum chemical indices for the intermediate states of the metabolic transformation are correlated with the carcinogenic activity of PAH. This indicates that the averaged chemical shift can be applied to investigate the metabolic transformation of carcinogenicity.

Carcinogens↗
PubMed1992

A study of embolizing materials for chemo-embolization therapy of hepatocellular carcinoma: embolic effect of cisplatin albumin microspheres using chitin and chitosan in dogs, and changes of cisplatin content in blood and tissue.

Hepatic artery of dogs was embolized with cisplatin (CDDP) albumin microspheres containing chitin and chitosan to investigate the in vivo CDDP release kinetics from CDDP albumin microspheres, the CDDP cumulative characteristics in the liver, and the influence of microsphere administration on hepatic tissue. Results showed that changes in blood CDDP content were dependent on CDDP albumin microsphere type and that release kinetics were better sustained when chitin was added to the microspheres or when the microspheres were treated with chitosan. In particular, the administration of CDDP in the chitin-containing CDDP chitosan albumin microspheres showed a blood CDDP content of approximately 0.26 micrograms Pt/ml 14 d after administration. The administration of chitin-containing or chitosan treated CDDP microspheres showed a CDDP content in the hepatic tissue of 0.14 to 0.23 micrograms Pt/g 28 d after administration. They also showed better control of CDDP release than those without chitin or chitosan treatment. No CDDP influence on hepatic tissue was observed. We conclude that, even in vivo, chitin and chitosan are effective embolic materials.

Animals↗
PubMed1992

Direct effect of ACTH on renin release in isolated perfused guinea-pig kidneys with adrenal glands.

To investigate the direct effect of corticotropin (ACTH) on the renin-angiotensin-aldosterone system, isolated guinea-pig kidneys with adrenal glands were perfused with various doses of ACTH (0.1-1000 micrograms/l) and 0.3 mmol/l of dibutyryl cyclic AMP (cAMP) through each cannula inserted into the abdominal aorta and the inferior caval vein. Perfusate renin activity was increased in a dose-dependent manner by the addition of ACTH in a range of 0.1-1000 micrograms/l, and reached a plateau at 20 min with each dose. The perfusate cAMP level was dose-dependently increased with 10-1000 micrograms/l of ACTH. Perfusate renin activity was also markedly increased by the addition of dibutyryl cAMP. The same effects of ACTH on renin and cAMP secretions were observed in the kidney perfusion model from which the adrenal glands were excluded. Aldosterone secretion failed to respond to 0.1 micrograms/l of ACTH, and was increased by higher concentrations (1-1000 micrograms/l) in the same experiments. These results demonstrate that ACTH has a direct effect on renal renin release in a physiological concentration (0.1 micrograms/l), and that the action of ACTH is probably mediated by cAMP. The sensitivity of renin release to ACTH stimulation is no less than that of aldosterone secretion during ACTH infusion, so it is possible that ACTH is an important stimulator of the renin-angiotensin system.

Adrenal Glands↗
PubMed1992

[Histological observations on structure of endomysium, perimysium and epimysium of lateral pterygoid muscle in rat].

To understand the muscle as a locomotorium, I observed the structure of the connective tissue sheaths (the endomysium, the perimysium and the epimysium) in the mature rat lateral pterygoid muscle. The following results were obtained using the macroscopy and light and electron microscopy. The lateral pterygoid muscle consists of two parts. The superior head originates from the basisphenoid and is mainly inserted into the articular disk and capsule. The inferior head originates from the lateral pterygoid processus and is mainly inserted into the condylar processus of the mandible. The perimysium is thick and bound the fasciculus secondarily as sheaths near the insertion of the superior head. The collagenous fibers are very fine in the endomysium. The collagenous fibers that make the connective tissue sheaths arrange on a skew against the muscle fibers, but parallel around the origin and the insertion. It seems that the connective tissue sheaths in the rat lateral pterygoid muscle, in view of the morphology, retain the forms of fasciculus, act as the runways for the muscle fibers in time of expansion and contraction and offer spaces for the attachment of the muscle fibers.

Animals↗
PubMed1992

[The long-term effect of high-dose beclomethasone dipropionate on the pituitary-adrenal function].

The pituitary-adrenal function was studied in seven asthmatic subjects who had been received daily inhalations of 800 to 1,000 micrograms of beclomethasone dipropionate (BDP) over a year. None of the subjects had taken oral corticosteroids for at least six months prior to the study. As indices of pituitary-adrenal function, 1) circadian rhythm of plasma ACTH and cortisol, 2) urine 17-OHCS and 17-KS, and 3) the response of cortisol in rapid ACTH test were examined. All subjects showed normal circadian rhythms of plasma ACTH and cortisol levels. Urinary 17-OHCS and 17-KS excretions over a 24-hour period were also within the normal range. Plasma cortisol levels in the rapid ACTH test were significantly increased and judged as normal responses in all subjects. These results indicate that long-term treatment with BDP ranging from 800 to 1,000 micrograms/day induces no suppressive effect on the pituitary-adrenal function.

Adrenocorticotropic Hormone↗