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Biomedical subjects

S Aoki

Publications and source records attributed to S Aoki.

At least 595 records · Page 33Linked to original sources
PubMed1984

Preparation of spherically agglomerated crystals of aminophylline.

The spherically agglomerated crystals of aminophylline (theophylline-ethylenediamine complex) can be compounded directly into pharmaceutical formulations without further processing, e.g., granulation. Such crystals were prepared by mixing theophylline and ethylenediamine in a partially miscible solvent system, i.e., organic solvent-ethanol-water. The organic solvents used were chloroform, 1-hexanol, isopropyl acetate, isobutyl acetate, isoamyl acetate, benzene, toluene, n-hexane, or n-heptane. Spherical crystallization depended upon the solubility of theophylline in the solvent mixture. The resultant agglomerated crystals were identical with the theophylline-ethylenediamine complex by IR, X-ray, and differential scanning calorimetry analyses, and was the alpha-, beta-, or gamma-form when the water of crystallization was less than or equal to 0.5, 1.0, and 2.5 mol, respectively. When the amount of ethylenediamine used was less than 1.1 mL (0.0165 mol), the resultant agglomerated crystals were converted to anhydrous theophylline by washing with ethanol. When water was added to the system (greater than or equal to 0.3 mL, i.e., 0.0167 mol), water was occluded in the resultant agglomerates as water of crystallization. Ethylenediamine content in the agglomerated crystals could be controlled by changing the amount of ethylenediamine added in the crystallization solvent.

Aminophylline↗
PubMed1984

The appearance and characterization of cyanide-resistant respiration in the fungus Candida albicans.

The respiration of yeast-form cells of the dimorphic fungus Candida albicans became resistant to cyanide during aging treatment in the resting state. An alternative, cyanide-resistant respiratory pathway was found to develop fully in cells aged at a concentration of 0.75 X 10(9)/ml or more at 25 C, but did not appear at 5 C. Chloramphenicol did not prevent the appearance of the alternative respiratory pathway. The effects of inhibitors, salicylhydroxamic acid (SHAM) and disulfiram (tetraethylthiuram disulfide), on respiration of aged cells were examined, and results indicated that SHAM binds at a site on the alternative respiratory pathway whereas disulfiram binds at two sites, one on the conventional respiratory pathway and the other on the alternative pathway. Thus, SHAM is a more selective inhibitor of the alternative respiration of C. albicans cells. SHAM-titration of the alternative respiration revealed that less than 10% of the maximal activity of the alternative respiratory pathway was utilized under normal conditions, indicating that the alternative respiratory pathway makes a small contribution to the total respiration. It was therefore concluded that the alternative, cyanide-resistant respiratory pathway operates fully when the cyanide-sensitive, cytochrome pathway is blocked although aged cells possess both respiratory pathways.

Binding Sites↗
PubMed1984

Increased sister chromatid exchange in human lymphocyte cultures infected with mycoplasma.

The effects of fermenting, poorly arginine-utilizing Mycoplasma fermentans and arginine-utilizing Mycoplasma salivarium on the frequency of sister chromatid exchange (SCE) in cultured human lymphocytes were examined. M. fermentans caused no apparent mitosis inhibition of lymphocytes and the increase in SCE frequency was dependent on the inoculum size of the mycoplasma. An evident increase in SCE frequency was observed in lymphocytes infected with smaller inoculum sizes of M. salivarium whereas there was mitosis inhibition of lymphocytes infected with larger inoculum sizes of the mycoplasma. In lymphocyte cultures infected with M. salivarium, the addition of arginine to the culture medium reduced mitosis inhibition but did not diminish the increase in SCE frequency, indicating that arginine depletion was not involved in causing the induction of SCEs in mycoplasma-infected lymphocytes. With regard to the genetic effectiveness of SCE, these results suggested that mycoplasmas are capable of inducing cytogenetic changes in infected host cells.

Arginine↗
PubMed1984

Studies on experimental immune complex nephritis (3). Therapeutic effect of prostaglandin E1 alpha-cyclodextrin host molecule (PGE1 . CD) on serum sickness nephritis in rats.

The effect of prostaglandin E1 alpha-cyclodextrin host molecule (PGE1 . CD) was estimated by using a model of immune complex glomerulonephritis induced in rats by i.v. injection of 1 mg of rabbit serum albumin every other day. PGE1 . CD was given subcutaneously for 10 days after nephritis was definitely induced and resulted in a rapid restoration of various biochemical parameters, especially in plasma. The continuous s.c. administration of PGE1 . CD (300 micrograms/rat/day) with a mini osmotic pump provoked a therapeutic effect similar to that obtained with twice daily s.c. administration of PGE1 . CD (300 micrograms/rat X 2/day). Both PGE1 . CD groups revealed less glomerular damage and fewer locations of immune complexes in glomeruli as demonstrated by light and immunofluorescence microscopy. The beneficial effect of PGE1 . CD may be associated with reduced immune complex deposits in glomeruli. The present studies suggest that PGE1 . CD may enhance the clearance of immune complex deposits from the glomeruli rather than inhibiting the formation of immune complex in the circulation.

Acetylglucosaminidase↗
PubMed1984

Studies on the mode of delivery and the outcome of small preterm infants with less than 32 weeks of gestation.

The purpose of this study is to make the relationship clear between the mode of delivery and the outcome of small preterm infants. A total of 91 tiny infants who were delivered before 32 weeks of gestation at Seirei Hamamatsu Hospital (between July 1, 1977 and January 31, 1983) and were studied retrospectively. Mean and standard deviation of birth weight and gestational age were 1215 +/- 388 grams and 28.2 +/- 2.4 weeks. The following results were obtained in the present study: 1) breech vaginal delivery of a tiny infant was a associated with an alarmingly high neonatal mortality rate, 2) infants weighing less than 750 grams had a very low survival rate among any of the modes of delivery, 3) infants delivered before 28 weeks of gestation had a poor survival rate, 4) an elective cesarean section of the infants weighing between 750 and 1499 grams showed a lower 28 days mortality rate than an emergency cesarean section or a breech vaginal delivery, though there were no statistical differences between a cephalic vaginal delivery and an elective cesarean section, 5) the frequency of intracranial hemorrhage was significantly lower among the elective cesarean sections than the others.

Birth Weight↗
PubMed1983

Adult T-cell leukemia observed at Niigata University Hospital.

Eight patients with adult T-cell leukemia (ATL) were observed at Niigata University Hospital during the last seven years. They had typical hematological findings of ATL. All patients tested possessed both natural antibody against ATL-associated antigens (ATLA) in the serum and ATLA in peripheral mononuclear cells. These findings agree with the results of virological analysis in patients with ATL in other areas of Japan and human T-cell leukemia (HTL) in the U.S.A. Six out of the eight patients were native residents of Sado Island in Niigata Prefecture. They showed somewhat different clinical features from patients in other endemic areas and a variety of skin lesions. It was noticeable that the skin lesion regressed spontaneously in two patients. In view of the fact that the total population of this island is about 80,000, the incidence of ATL is thought to be high. Immunological studies were performed in our patients and the immunological background of ATL is discussed.

Adolescent↗