Search PubMed⌕ Search

Biomedical subjects

S Hamada

Publications and source records attributed to S Hamada.

At least 469 records · Page 26Linked to original sources
PubMed1981

[Two cases of the diencephalic syndrome were reported with hormonal studies (author's transl)].

Two cases of the diencephalic syndrome were reported with hormonal studies. The first case was initially admitted at her age of 4 years and 10 months old. Progressive visual disturbance and horizontal nystagmus had developed one year prior to the admission. Her weight gain had stopped since 10 months old. Partial removal of the hypothalamic pilocytic astrocytoma and 5,000 rad of lineac radiotherapy brought satisfactory effects on her previous symptoms. She was readmitted, however, at her age of 8 years and 10 monts old because of precocious puberty. Her breast development was in Tanner's grade 2, and her bone maturation was equivalent to one of 11 years old. Hormonal studies showed decreased urine 17-OHCS and 17-KS, elevated serum LH, E1 and E2. The CT scan disclosed some enhanced area in the vicinity of the optic chiasm, which had not changed for the last one year. The second case was admitted at his age of 10 years and 9 months old because of progressive marked emaciation of 6 months' duration. Parinaud's sign was only positive neurological finding. The CT verified enhanced areas in the pineal and chiasm. Cytological study of CSF gave the diagnosis of germinoma. Hormonal studies showed decreased urine 17-OHCS and 17-KS, decreased T3, T4, ACTH, and increased PRL as well as increased HGH. Local lineac irradiation by 5,500 rads was given, during which the enhanced area in CT disappeared and his weight gain started. Increased HGH became normalized but paradoxical response of HGH to GTT remained same.

Astrocytoma↗
PubMed1980

Interaction of glucosyltransferase from Streptococcus mutans with various glucans.

Cell-free glucosyltransferase of Streptococcus mutans strain B13 (serotype d) exclusively synthesized water-insoluble glucan from sucrose. The insoluble glucan possessed strong glucan-associated glucosyltransferase activity even after extensive washing and lyophilization. Furthermore, cell-free glucosyltransferase became bound to heat-treated water-insoluble glucan or to heat-treated S. mutans B13 cells grown in Todd Hewitt broth, and the resulting glucan and cells adhered to a glass surface in the presence of exogenous sucrose. No other water-insoluble glucans bound significant quantities of glucosyltransferase. Glucan synthesis by free or glucan-bound glucosyltransferase was stimulated by low concentrations (1 to 5 mg ml-1) of isomaltose or water-soluble dextrans of various molecular weights, but higher concentrations (10 mg ml-1) inhibited glucan synthesis. The glucan synthesized in the presence of primer dextrans exhibited a reduced ability to adhere to a glass surface. Certain sugars such as maltose and fructose significantly lowered the yield of insoluble glucans. Preincubation of glucosyltransferase with the low molecular weight dextran T10 increased subsequent binding to S. mutans B13 insoluble glucan, whereas preincubation with higher molecular weight dextrans significantly inhibited the glucosyltransferase binding.

Adhesiveness↗
PubMed1980

Isolation and serotyping of Streptococcus mutans from teeth and feces of children.

Streptococcus mutans were detected in the feces from 10 of 29 caries-active patients, aged 4 to 9 years. The percentage of S. mutans to the total counts of facultatively anaerobic streptococci on mitis salivarius agar (Difco Laboratories) varied from 0 to 72.5%. S. mutans were then isolated from dental plaque of sound teeth and carious dentin of the 10 subjects known to harbor S. mutans in the feces. The frequency distribution of various serotypes of these dental and fecal isolates of S. mutans was compared by the immunodiffusion technique. Of the total 1,047 isolates (290 isolates from feces, 289 from dental plaque, and 468 from carious dentin), type c isolates were most prevalent (ca. 66%). Serotype d, e, f, and g isolates were also found but in far lower frequencies. Plural serotypes of S. mutans were occasionally found in dental and fecal samples of a single subject. For two subjects, relatively rare serotypes of S. mutans in the population examined, serotype e, f, or g, were predominantly found in their fecal and dental samples and those of their siblings and mother, suggesting an intrafamilial transmission of S. mutans.

Child↗
PubMed1980

Isolation and immunobiological classification of Streptococcus sanguis from human tooth surfaces.

A total of 113 pure cultures of Streptococcus sanguis were obtained from dental plaque samples of 64 subjects. All isolates synthesized glucan from sucrose, elaborated peroxide, and were alpha-hemolytic. Two biotypes and four serotypes were differentiated within the species. Biotype A (95 isolates) fermented salicin and inulin and hydrolyzed arginine and esculin, whereas biotype B (18 isolates) did not possess these activities. The isolates were serotyped with autoclaved extracts against whole-cell antiserum to strains ATCC 10556 or ST3 (serotype I), ATCC 10557 (serotype II), ATCC 10558 (serotype III), and ST7 (serotype IV), by the capillary precipitin test. Serotypes I, II, III, and IV were found to consist of 24, 16, 37, and 15 isolates. Type IV was demonstrated anew in this study. The remaining 21 isolates were not typed because of either multiple reactions or nonreactivity against the standardized typing sera. All isolates of serotype II belonged to biotype B, which resembles Streptococcus mitior physiologically. Five isolates representing four serotypes and an untypable strain were examined for their cariogenicity against specific-pathogen-free Sprague-Dawley rats fed high sucrose diet no. 2000. Organisms of each isolate were established in the mouths of the rats, but only three isolates induced weak caries that were restricted to pits and fissures of occlusal surfaces of the teeth.

Adolescent↗
PubMed1980

Changes in some biological properties of Streptococcus salivarius isolates from infected rats.

Isolation of colonies with altered colonial morphology was frequently observed following infection of specific pathogen-free rats fed a caries-inducing high sucrose diet with two human strains of Streptococcus salivarius. These isolates produced unique rough colonies on mitis salivarius agar, in contrast to the smooth, mucoid colonial morphology of the parental strain. The rough variants were characterized by a marked increase in the synthesis of polysaccharide from sucrose, especially cell-associated water-insoluble glucan, whereas the smooth parental strains mainly produced cell-free fructan. Glucose-grown cells of rough variants but not smooth parental strains were aggregated upon addition of sucrose. Such variants were not detected during laboratory transfers of the human strains of S. salivarius nor by mutagenesis of the cultures.

Animals↗