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Biomedical subjects

Y Yasuda

Publications and source records attributed to Y Yasuda.

At least 235 records · Page 13Linked to original sources
PubMed1990

Permeability of gentamicin and polymyxin B into the inside of Bacillus subtilis spores.

The penetration of gentamicin and polymyxin B into the inside of Bacillus subtilis spores was examined by an immunoelectron microscopy method with colloidal gold--immunoglobulin G (IgG) complex. The colloidal gold particles were located predominantly in the coat region of both gentamicin-treated and polymyxin B-treated spores and were hardly observed in the other regions, i.e., the cortex and core regions. When these antibiotic-treated spores were subsequently treated with CaCl2, the number of gold particles bound to the coat region was greatly decreased. These results suggest that these two antibiotics are able to penetrate into the spore coat but not into the cortex or core, that is, the primary permeability barrier to them exists between the coat and the cortex regions.

Amino Acids↗
PubMed1990

[Quantitation of IgG antibodies to type Ia group B streptococcal type-specific polysaccharides measured by enzyme-linked immunosorbent assay].

The type-specific polysaccharide antigen of the group B streptococcus (GBS) type Ia as extracted and purified according to the procedures of Kane and Karakawa. Using this purified polysaccharide antigen, we made a sensitive and specific assay system of enzyme-linked immunosorbent assay (ELISA) and measured the titres of of the type-specific antibodies in maternal sera and cord blood sera. The titres of antibodies in 78 pregnant women (26 Ia carriers, 18 other types of GBS carriers and 34 non carriers) were compared. A mother of an infant affected by early onset infection of GBS Ia had a titre of antibody 1:10 at delivery, while 2 years later she became a non carrier and had a titre of antibody over 1:160. The titres of antibodies in 27 pair sera of mothers and cords were well correlated.

Antibodies, Bacterial↗
PubMed1990

Biochemical and biopharmaceutical properties of macromolecular conjugates of uricase with dextran and polyethylene glycol.

Uricase (UC) was conjugated with dextran and polyethylene glycol and their biochemical and biopharmaceutical properties were studied. UC-dextran conjugates (UC-D) synthesized by four methods, periodate oxidation, cyanogen bromide, carbodiimide and cyanuric chloride largely retained the UC enzymatic activity depending on the extent to which they modified amino groups. The periodate oxidation method seemed best because it gave a conjugate with high yield and satisfactory activity retention. The conjugate of UC with activated polyethylene glycol (UC-PEG2) was also obtained with high yield but the remaining activity was somewhat lower than those of dextran conjugates at the same modification extent. UC-D and UC-PEG2 showed sustained enzymatic activity in plasma after intravenous injection to rats. The advantage of chemical modification of proteins, especially with dextran, by the periodate oxidation method for preparation of a protein-delivery system was thus suggested.

Animals↗
PubMed1990

Isolation and structural elucidation of new cyclotetrapeptides, trapoxins A and B, having detransformation activities as antitumor agents.

New cyclotetrapeptides, trapoxins A and B were isolated from the culture broth of Helicoma ambiens RF-1023. These compounds exhibit detransformation activities against v-sis oncogene-transformed NIH3T3 cells (sis/NIH3T3) as antitumor agents. The structures were found to be new cyclotetrapeptides, cyclo[(S)-phenylalanyl-(S)-phenylalanyl-(R)-pipecolinyl- (2S,9S)-2-amino-8-oxo-9,10-epoxydecanoyl-] for trapoxin A and cyclo[(S)-phenylalanyl-(S)-phenylalanyl-(R)-prolyl-2- amino-8-oxo-9,10-epoxydecanoyl-] for trapoxin B, by X-ray analysis, mass spectrometric, NMR and chemical studies.

Amino Acid Sequence↗
PubMed1990

Prevalences of malocclusions and dental caries in molars in female adolescents.

Prevalences of malocclusions and dental caries in molars were investigated on a database of high school students collected between 1977 and 1986. A total of 6,665 schoolgirls were evaluated. The proportions of 54.1% in the seventh grade and 56.6% in the tenth grade students were judged as having malocclusions. The prevalences of dental caries for the lower first and the second molars were significantly higher (p less than 0.001) than those for the upper opponents during the observation period. The prevalence of dental caries increased linearly for all kinds of molars in accordance with age, but they were lower than those reported by the Ministry of Health and Welfare in Japan determined for the entire nation. The percent of dental caries for the second molars revealed abrupt increases from 10% at the seventh grade to 50% at the 12th grade. These changes were particularly noticeable between the eighth and the tenth grades. These results suggest the significance of oral health care education during the adolescent period based on a long-term cooperation made by dentists, school nurses, teachers through the participation of students into the oral health care programme.

Adolescent↗
PubMed1990

[Prevalence of malocclusions and demand for orthodontic treatment among students at a women's high school].

Prevalences of malocclusions were investigated in a sample of 3,520 girls recorded between 1984 and 1986 at a private high school. Also, proportions of students who had received and were under treatment were surveyed for 3,501 students in 1989. In addition, ratios of a number of those who were judged to reveal maxillary protrusion with respect to that of the whole sample examined were evaluated as a function of overjet. The results of the surveys are as follows. SURVEY I) A total prevalence of malocclusion was 57.9% in the Grade 7 (G7) and 56.4% in the Grade 10 (G10). Among malocclusions surveyed, maxillary protrusion was found in 8.1% of the G7 and in 7.8% of the G10. Deep overbite was determined in 7.9% of the G7 and in 7.6% of the G10, mandibular protrusion was found in 2.4% of the G7 and in 2.7% of the G10. Edge-to-edge incisor relationships were determined in 6.4% of the G7 and in 7.6% of the G10. Anterior open bite was found in 2.4% of the G7 and in 2.9% of the G10. Crowding was found in 37.3% of the G7 and in 33.9% of the G10. SURVEY II) Prevalence of students who had orthodontic treatment at the time of survey, was 6.4% in the G7, 7.0% in the G8, 6.0% in the G9, 6.0% in the G10, 5.4% in the G11, and 3.6% in the G12. Those who had had orthodontic treatment revealed proportions of 8.1% in the G7, 8.0% in the G8, 7.7% in the G9, 11.3% in the G10, 12.2% in the G11, and 13.7% in the G12 students. SURVEY III) A proportion of 73.5% of those who had overjets more than 6 mm were judged to have maxillary protrusion.

Adolescent↗
PubMed1990

Interferon-alpha treatment leads to accumulation of virus particles on the surface of cells persistently infected with the human immunodeficiency virus type 1.

The effect of interferon-alpha (IFN-alpha) on virus replication in cells acutely infected with human immunodeficiency virus type 1 (HIV-1) and virus production from cells persistently infected with HIV-1 was studied. In both cell systems, significant suppression was observed. However, this suppression was not due to protein synthesis of the major viral proteins. Electron microscopy revealed the accumulation of intact virus particles on the cell surface of the cells treated with IFN-alpha. Thus, IFN-alpha might suppress the release stage of the particle from infected cells.

Cell Line↗
PubMed1990

[A case of polymyositis associated with primary biliary cirrhosis].

We studied a 67-year-old female suffered from polymyositis associated with primary biliary cirrhosis. She was pointed out liver dysfunction by screening test. Alkaline phosphatase, transaminase, and IgM were increased. Antimitochondrial antibody and antinuclear antibody were positive. Liver biopsy showed cell infiltrations in Glisson's capsules and destruction of cholangioles, being diagnosed as primary biliary cirrhosis (Scheuer Stage I). Four years later she showed a muscle weakness of four extremities and admitted to our department. Neurological examination revealed a severe weakness and atrophy of both proximal and distal muscles. Deep tendon reflex was decreased on four extremities. Laboratory examination showed a creatine kinase level of 312 IU/L, alkaline phosphatase 238 IU/L, gamma-glutamyl-transpeptidase 140 IU/L, Igm 416 mg/dl, antimitochondrial antibody titer 1:320, and antinuclear antibody titer 1:320. Muscle biopsy findings were compatible with polymyositis. Electron microscopic examination disclosed diffuse increase of mitochondria in subsarcolemma and intermyofibrils. Until now eight cases with polymyositis associated with primary biliary cirrhosis have been reported, but electron microscopic examination of muscle has not been carried out. It is necessary to examine mitochondria of muscle and liver in patients with polymyositis associated with primary biliary cirrhosis for the elucidation of its etiology.

Aged↗
PubMed1990

[Computed tomography of obturator foramen hernia].

A 89 year-old female was admitted with the complaint of right hypochondralgia. And also she complained of right thigh pain after admission. On hospital day 4, she underwent CT examination in order to evaluate right thigh with severe pain. The preoperative diagnosis of obturator foramen hernia was performed.

Aged↗
PubMed1990

[Hepatic hemodynamics after hepatectomy and the effect of administration of glucagon].

The effect of hepatectomy and administration of glucagon on hepatic hemodynamics were studied using mongrel dogs. The results were as follows: 1) Hepatic blood flow in the 70% hepatectomized dogs was significantly less than that in dogs subjected to sham operation or 40% hepatectomy. 2) Bolus injection of glucagon (10 micrograms/kg) increased blood flow in the hepatectomized dogs as well as that in the control dogs. The percentage increment, however, was significantly smaller in the 70% hepatectomized dogs, possibly due to little increase of portal vein blood flow. 3) Portal vein pressure and its resistance were significantly higher in the 70% hepatectomized dogs than in both the 40% hepatectomized dogs and the control dogs. 4) Although pre-sinusoidal resistance showed no significant difference among these three groups, post-sinusoidal resistance increased stepwise in the order of extent of hepatectomy. These results suggest that administration of glucagon after extended major hepatectomy is not so particularly effective in generating adequate hepatic tissue blood flow.

Animals↗
PubMed1990

[A case of herpes zoster myelitis improved with acyclovir].

A case of herpes zoster myelitis improved with acyclovir was reported. A 71-year-old female showed a rash over the S2-4 dermatomes on the right side. After that, paraplegia and dysuria progressed. Patellar tendon reflex was exaggerated, but Achilles tendon reflex was normal. Babinski and Chaddock sign were bilaterally elicited. Superficial sense was markedly decreased below the Th12 dermatome. Vibration sense was slightly decreased but position sense was normal on the lower extremities. Cerebrospinal fluid analysis revealed pleocytosis, and an elevation of IgG and varicella-zoster virus antibody titer. Acyclovir (250 mg bid/day) was given for ten days. Paraplegia, sensory disturbance and dyschezia improved but dysuria did not. In this case acyclovir administration was started on the 18th day after the onset of myelopathy. Early initiation of acyclovir treatment might lead to recovery of dysuria. As the pathogenic mechanism of herpes zoster myelitis is considered to be direct viral invasion of the spinal cord with subsequent necrosis, early initiation of acyclovir treatment is necessary for the recovery.

Acyclovir↗
PubMed1990

[Bronchial atresia of additive anomalous bronchus].

A case of bronchial atresia of additive anomalous bronchus in right middle lobe was reported. A mass and emphysematous lung were found on the chest roentgenogram. CT, and MRI, and it is not difficult to diagnose.

Bronchi↗
PubMed1989

Ganglioside-specific binding protein on rat brain membranes.

A derivative of ganglioside GT1b (IV3NeuAc,II3(NeuAc)2-GgOse4) with an active ester in its lipid portion was synthesized and covalently attached to bovine serum albumin (BSA). The conjugate, having four GT1b molecules per albumin molecule [GT1b)4BSA) was radioiodinated and used to probe rat brain membranes for ganglioside binding proteins. A ganglioside-specific, high affinity (KD = 2-4 nM), saturable (Bmax = 13-20 pmol/mg membrane protein) binding site for 125I-(GT1b)4BSA was demonstrated on detergent-solubilized rat brain membranes adsorbed to filters. 125I-(GT1b)4BSA binding was tissue-specific (more than 35-fold greater to brain than to liver membranes) and was nearly eliminated by pretreatment of brain membrane-adsorbed filters with trypsin (1 microgram/ml). Underivatized gangliosides added as mixed detergent-lipid micelles blocked 125I-(GT1b)4BSA binding to brain membranes; structurally related GQ1b, GT1b, and GD1b were the most potent (half-maximal inhibition at 70-110 nM), while half-maximal inhibition by other gangliosides (GD3, GD1a, GM3, GM2, and GM1) required 5-20-fold higher concentrations. Other sphingolipids, neutral glycosphingolipids, and glycoproteins were poor inhibitors, and treatment of (GT1b)4BSA with neuraminidase attenuated its binding. Although most phospholipids were noninhibitory, phosphatidylinositol and phosphatidylglycerol inhibited half-maximally at 400-600 nM. However, inhibition of 125I-(GT1b)4BSA binding by gangliosides was competitive and reversible while that by phosphatidylinositol and phosphatidylglycerol was not. Ganglioside-protein conjugate binding reveals ganglioside-specific brain membrane receptors.

Animals↗
PubMed1989

Aberrant differentiation of neuroepithelial cells in developing mouse brains subsequent to retinoic acid exposure in utero.

All-trans-retinoic acid induced 2 types of disorganized neuroepithelium, localized and continuous, in the exencephaly of 9-day-old mouse embryos exposed to 60 or 40 mg/kg for 27 to 30 hr in utero. The localized effect appeared as a protuberance in the wall of the telencephalon and thick neural folds in the mesencephalon with the discontinuity of the apical terminal sheet. The continuous disorganization was seen from the olfactory placode to the myelencephalon with rosettes of cells and many dense bodies in the neuroepithelium. Ultrastructurally, cells in the localized disorganizations showed swelling of Golgi complexes, coated vesicles, and rough endoplasmic reticulum resulting in degeneration. The continuous disorganizations consisted of undifferentiated homogeneous cells in which the nuclei exhibited expansion of nucleolar granular portions and coagulated heterochromatin, and cytoplasm showed monosomal dispersion. In both types of disorganized neuroepithelium, junctional complexes were seen focally at the apical side or apical processes of the rosette, with few or no microfilament bundles. A layer of microfilaments at the base of the neuroepithelial cells in controls, just above the basal lamina, was not present in the monosome dispersed cytoplasm. In the neuroepithelium of controls, one phagosome was seen in the perinuclear region in 0.8% of the cells examined, whereas in the experimental neuroepithelium 2 or more phagosomes were seen in a cell, and phagocytosis occurred by pseudopods. These findings suggest that all-trans-retinoic acid induces not only cytotoxicity but also dedifferentiation in the neuroepithelial cells leading to more cell death, which activates the phagocytosis. These lesions in the neuroepithelium may be a cause of exencephaly.

Abnormalities, Drug-Induced↗
PubMed1989

Suppression of erythroid cell differentiation in mouse embryos exposed to retinoic acid in utero.

Differentiation of circulating erythrocytes was inhibited by all-trans-retinoic acid in 8- and 9-day-old mouse embryos exposed in utero on day 8 of gestation. Histochemical, light, and electron microscopic examinations revealed that all-trans-retinoic acid first decreased the numbers of polychromatic erythroblasts and then increased them. Simultaneously, immature erythroblasts proliferated, and differentiation of mature primitive erythrocytes was suppressed. Electron microscopy of these immature erythroblasts revealed monosomes rather than the usual polyribosomes in the cytoplasm. RNA histochemistry revealed a greater number of intermediate differentiating erythroblasts with pyronin-positive cytoplasm than those in the controls and revealed also a dose-dependent relationship between the number of polychromatic erythroblasts with positive pyronin staining and the controls. These findings suggest that all-trans-retinoic acid destroys the messenger RNA system, resulting in an inability to produce hemoglobin.

Animals↗
PubMed1989

Electron spin resonance studies of erythrocyte membrane in spinocerebellar degeneration.

Erythrocyte membrane fluidity was examined by electron spin resonance spectra using nitroxide fatty acid spin labels in spinocerebellar degeneration (SCD). Subjects with SCD, motor neuron disease (MND) and controls did not differ in fluidity of the deep site (hydrophobic region) of the erythrocyte membrane. However, the fluidity of the shallow site (hydrophilic region) in the erythrocyte membrane was significantly less fluid in SCD than in controls and MND (outer hyperfine splitting of 5-nitroxide stearic acid: SCD 54.70 +/- 0.43 G, controls 53.57 +/- 0.41 G, MND 53.54 +/- 0.35 G, P less than 0.001). Serum HDL-cholesterol and membrane fluidity correlated significantly in controls, but not in SCD. A significant negative correlation between age and membrane fluidity was found in SCD, but not in controls. These data suggest that membrane abnormality exists in SCD and may be concerned with aging.

Adolescent↗
PubMed1989

Sulindac-induced aseptic meningitis in mixed connective tissue disease.

A 21-year-old female with mixed connective tissue disease (MCTD) experienced nausea, headache, consciousness disturbance, nuchal rigidity, and a temperature of 38.5 less than or equal to C three days after the intake of sulindac (300 mg/day). Cerebrospinal fluid analysis revealed an opening pressure of 310 mm of water, a predominantly lymphocytic pleocytosis, and elevated protein content of 89 mg/dl. After discontinuing sulindac, the aseptic meningitis improved in five days. In the acute stage, CT scan disclosed contrast enhancement in the cerebral hemispheres, which suggests that hypersensitivity may be involved in the pathogenesis of nonsteroidal antiinflammatory drug (NSAID) induced aseptic meningitis.

Adult↗