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Biomedical subjects

Y Hirano

Publications and source records attributed to Y Hirano.

At least 163 records · Page 9Linked to original sources
PubMed1994

[Isolation of methicillin resistant Staphylococcus aureus from nasopharyngeal swabs on admission to a ward for pediatric patients].

Between 1992 and 1993, 2313 nasopharyngeal swabs were taken and cultured from 1665 patients on admission to a pediatric ward at Asahikawa Kosei Hospital. Twenty nine strains of Methicillin resistant Staphylococcus aureus (MRSA) were isolated from 28 patients. The ages of these patients ranged from 2 months to 9 years and 14 patients were younger than 1 year. Their underlying diseases were bronchial asthma in 9 patients, prematurely born infants with chronic lung disease in 4. Fourteen patients had a history of admission during the past 6 months. No patient had infectious diseases due to MRSA.

Child↗
PubMed1994

Multiple kinetic effects of beta-adrenergic stimulation on single cardiac L-type Ca channels.

During beta-adrenergic stimulation, several different mechanisms are known to modulate single cardiac L-type Ca channels, such as an increase in the proportion of nonblank sweeps (availability), graded changes in open and closed time constants, and potentiation of "mode 2" gating. To clarify the interrelationships of the above mechanisms in terms of "molecular modulation," we reevaluated the adenosine 3',5'-cyclic monophosphate-dependent increase in single cardiac Ca channel activity under conditions where all of the proposed mechanisms could take place. We observed considerable variations in the kinetic properties of basal channel activity among individual patches, presumably due to the diversity of intracellular metabolic conditions of individual myocytes. This made the contribution by each mechanism as described above variable from one patch to another. Increases in open probability during nonblank sweeps (associated with increased open time constant and/or promotion of mode 2 gating) were observed in patches were the increased nonblank rate was already established in the control state. In contrast with the report by D. T. Yue, S. Herzig, and E. Marban (Proc. Natl. Acad. Sci. USA 87: 753-757, 1990), graded changes in the open time constant could take place independently from the potentiation of mode 2 gating behavior. Our results suggest that the enhancement of cardiac L-type Ca channels during beta-stimulation involves multiple functional modulatory sites, which might be phosphorylated independently.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1994

Mechanism of FK506-induced glucose intolerance in rats.

To clarify the mechanism of glucose intolerance induced by FK506, a novel immunosuppressant, 5 or 10 mg/kg/day of FK506 was dosed orally to rats for 2 weeks, and 125I-insulin binding to the erythrocytes, plasma glucose and insulin levels, and pancreatic insulin content were examined. Insulin binding to the erythrocytes of rat dosed with FK506 was similar to that to erythrocytes of the placebo control; Scatchard analysis confirmed that FK506 did not cause damage to the insulin receptor of the erythrocytes. Contrarily, FK506 caused a clear decrease of pancreatic insulin content as well as a slight decrease of plasma insulin level. The results suggest that the glucose intolerance induced by FK506 is associated with a decrease of insulin secretion, but is not associated with impairment of the insulin receptor.

Animals↗
PubMed1994

Adsorption of salivary proteins to the surface of oral streptococcal cells.

Oral tissues, especially tooth surfaces, are covered with a layer of salivary proteins. Oral bacterial cells that adsorb to salivary components accumulated on the tooth surface are, as a rule, covered with the same components, especially proteins. Thus, it is possible that the salivary proteins covering the bacterial cells are related to the adhesion of bacteria to oral tissues. The aim of this study was to clarify the mechanisms of adsorption of salivary proteins to the surface of Streptococcus sanguis, S. mitis and S. salivarius using an adsorption assay with salivary proteins labeled with tritiated formaldehyde. The results showed that salivary proteins adsorbed more to S. salivarius than to S. mitis, and least to S. sanguis. It was evident that hydrophobic bonding was involved in the adsorption of salivary proteins to the bacterial cells tested. The amount of salivary proteins adsorbed to S. mitis and S. salivarius was decreased by the presence of phosphate, that to S. sanguis was increased by the presence of a divalent cation such as Ca2+, and that to all bacteria tested was inhibited in different ways by the presence of sugars. The amount of salivary proteins adsorbed to S. sanguis and S. salivarius was reduced effectively by pretreatment of the cells with trypsin, chymotrypsin and papain. In the case of S. mitis, the amount of adsorbed salivary proteins was decreased by pretreatment of the cells with chymotrypsin only, and was increased by pretreatment with lipase. These results indicate that there are different mechanisms of adsorption of salivary protein to the cell surfaces of oral streptococci.

Acetylglucosamine↗
PubMed1994

Effects of dietary casein and soy-protein on metabolic conversion of eicosapentaenoic acid to docosahexaenoic acid in the liver of rat.

The differential effects of dietary proteins on the metabolic process of eicosapentaenoic acid (EPA, 20:5n-3) via docosapentaenoic acid (DPA, 22:5n-3) to docosahexaenoic acid (DHA, 22:6n-3) were studied using parameters calculated from the proportion of n-3 polyenoic acid in liver phospholipid (PL) of rats. Rats were given casein or soy-protein isolate (SPI) diet containing 3% EPA with or without methionine (Met) supplementation for 3 weeks. The (22:5 + 22:6)/20:5 and 22:5/20:5 ratios of the PL fractions in the liver of rats given SPI were evidently elevated compared with those given casein. These ratios were also elevated when linoleic acid (LA, 18:2n-6) was added to the diet. There were no significant differences in the 22:6/22:5 ratio of the same PL fractions between the casein and SPI groups without the addition of LA, but the ratio was lowered by the addition of LA. It was found that these parameters for metabolic conversion were not affected by supplementation of Met or by a decrease in body weight. The above results suggest that the elongation step from EPA to DPA is affected by the type of protein, i.e., it is accelerated by SPI and is not affected by the presence of LA, while the metabolic process from DPA to DHA is not affected by the type of proteins without the addition of LA but is suppressed when LA is added.

Animals↗
PubMed1994

[Crystalloids in salivary gland pleomorphic adenoma].

We examined crystalloids in salivary gland pleomorphic adenomas. The crystalloids were detected in 4 of 34 pleomorphic adenomas (11.7%). In three cases they were found in the minor salivary gland and in one case in the major salivary gland. Light microscopy revealed that all the crystalloids were in parenchyma. They were composed of eosinphilic structure and radially arranged clusters of needle-shape fibers. The central parts sometimes contained clear space. They were usually closely surrounded by neoplastic myoepithelial cells. All 4 cases containing crystalloids were million reaction-negative and positive to van Gieson, Mallory and Reticulin Silver Impregnation stains. Therefore all the crystalloids in our 4 cases were considered as collagen-rich.

Adenoma, Pleomorphic↗
PubMed1994

Mucinous cystadenocarcinoma of the pancreas with mucinous biliary obstruction due to uncommon complication of fistulas to the common bile duct and main pancreatic duct.

We report a case of biliary obstruction by a large amount of mucinous material produced by a cystadenocarcinoma of the pancreas invading the common bile duct. This diagnosis was made preoperatively by various imaging methods. Endoscopic retrograde pancreatography (ERP) revealed a mucus-containing cyst with a communication to the main pancreatic and common bile ducts due to a fistulization. Mucinous biliary obstruction was observed. This case indicates that mucinous biliary obstructions should be considered in patients with a mucinous cystic neoplasm of the pancreatic head in the presence of jaundice and that mucinous cystadenocarcinoma may develop into mucinous carcinoma, especially in cases with fistula formations. ERP is useful for detecting the presence of a fistula to the common bile duct or other neighboring organs in such cases. Surgical treatment is recommended because the prognosis of mucinous cystadenocarcinoma is better than that of the usual pancreatic cancer, even though the tumor shows a communication with neighboring organs.

Bile Ducts↗
PubMed1994

[Acute disseminated encephalomyelitis].

Acute disseminated encephalomyelitis (ADEM) follows certain viral infection or vaccinations, which has a close etiological relationship to experimental autoimmune encephalomyelitis (EAE). Immunological examinations have not been sufficiently carried out on human ADEM except postmeasles encephalomyelitis. The most important pathogenic role in ADEM might be changes of immune regulatory mechanisms by virus infection. Therefore, it would be very useful to investigate cytokine, adhesion molecules and receptors on neural cells and endothelial cells in the central nervous system. Recently, the incidence of postvaccinated encephalomyelitis has reduced. Neurologic complications of immunization have been still reported, however, there is no scientific method to prove that the association is causal or coincidental in an individual case.

Amino Acid Sequence↗
PubMed1994

[Clinical electrocochleographic study of widened AP-SP complex (broad wave)].

A clinical electrocochleographic study of 35 patients with cerebellopontine angle tumors and 49 patients with cochlear hearing losses was carried out using the transtympanic electrode technique. We defined a broad wave, of which the width of the AP-SP complex was more than 1.50 msec at 90 dBnHL stimuli using 4 kHz for one cycle click sound. We divided the waves into two types - an AP.SP mixed type and a dissociated type. Broad waves are not unique to retrocochlear hearing losses and are also seen in cases of severe high frequency hair cell damage whether cochlear or retrocochlear in origin. In cerebellopontine angle tumors, broad waves are not seen in cases with a typical retrocochlear pattern. We considered the dissociated type to have been broadened by severe high frequency hair cell damage in addition to the response at a lower frequency of about 1.5 to 4 kHz. We speculate that the broad wave, except in dissociated type, is caused by severe high frequency hair cell damage.

Adult↗
PubMed1993

Comparative developmental toxicity and metabolism of nitrazepam in rats and mice.

This study was designed to evaluate the developmental toxicity of nitrazepam (NZ) in Sprague-Dawley rats and ICR mice and to determine the metabolic factors which modulate susceptibility to the developmental effects of NZ. Rats were treated orally with a single dose of NZ at 300 mg/kg on Day 12 of gestation. Mice received one dose of 300 mg/kg NZ via gavage between Days 9 and 14 of gestation. NZ administration resulted in a significant incidence of malformations in rats, while no evidence of teratogenic action was observed in mice. Pronounced species differences in the metabolism of NZ were observed. In rats, 7-acetylaminonitrazepam (AANZ) was detected as the major metabolite in plasma and embryos, whereas in mice, only small amounts of this product were found. The rate of N-acetylation of 7-aminonitrazepam (ANZ) to AANZ was 8.5-fold greater in rat liver cytosol than that in mouse liver cytosol. In contrast, the rate of deacetylation of AANZ to ANZ was 9-fold greater in mouse liver microsomes than that in rat liver microsomes. The developmental effects of authentic metabolites of NZ were studied in the two species. A single oral administration of 300 mg/kg ANZ to pregnant animals produced a significant incidence of malformations in rats, but not in mice. On the other hand, AANZ was teratogenic in both species. These results suggest that the difference in the susceptibility to NZ-induced teratogenicity between rats and mice may be related to differences in the levels of N-acetyltransferase and deacetylase, and that AANZ may be involved in the teratogenic mechanism.

Abnormalities, Drug-Induced↗
PubMed1993

Histochemical analysis of blood group antigens in human sublingual glands and pancreas. An application of high-performance liquid chromatography to estimate the quantity of galactose liberated from tissue sections by alpha-galactosidase digestion.

Using immunostaining with monoclonal antibodies (mAbs) from three different sources as well as anti-B lectin, GSAI-B4 staining and alpha-galactosidase digestion, blood group B antigens were localized and analysed in tissue sections of sublingual glands from blood group B and AB individuals. Quantitative analysis of galactose was simultaneously carried out on the supernatant enzyme solution used for treating tissue sections by high-performance liquid chromatography (HPLC). In addition, galactose liberated from the pancreas tissues of blood group B and AB individuals was also estimated by HPLC analysis in order to compare the content of antigens. mAb-B(H079) and GSAI-B4 reacted uniformly with the mucous cells from blood group B and AB secretors. On the other hand, other mAbs-B(B006 and A582) recognized the antigen in a limited number of cells or was even negative in some cases of blood group AB individuals. Only mAb-B(H079) recognized the B antigens in mucous cells from non-secretors. Digestion with alpha-galactosidase resulted in the consistent appearance of H and Le(b) antigens in the mucous cells of all the secretors examined, although the reduction of staining intensity with anti-B reagents was not so marked. Le(y) antigens also appeared in some cases after the enzyme digestion. In non-secretors, Le(b) and Le(y) antigens, but not H antigens, appeared in some mucous cells following enzyme digestion. HPLC analysis of galactose revealed that alpha-galactosidase can specifically liberate the terminal galactose residues of B antigens, and no marked difference was present in the content of liberated galactose from mucous cells of sublingual glands among the individuals investigated (8.5-11.7 nmoles cm-2). No galactose was detected in samples from the sublingual glands of non-secretors, and only a trace amount of galactose was detected in the samples from pancreas tissues. These results suggest that the observed difference in the reactivity of different reagents with each tissue site can be ascribed to both quantitative and qualitative heterogeneity of B antigens.

Blood Group Antigens↗
PubMed1993

Oral absorption of FK506 in rats.

The oral absorption of FK506 in solid dispersion formulation was studied in rats. The obtained area under the concentration versus time curve (AUC) increased in a nonlinear fashion with a small dose-dependent increase in the peak blood concentrations (Cmax). The peak concentration time (Tmax) was observed within 30 min after administration in all dosing groups (1-10 mg/kg) with or without feeding, whereas the oral absorption of FK506 was reduced to about 50% by gavage at a dose of 1 mg/kg. Participation of first-pass elimination was suggested by comparing the blood levels after infusion via the portal vein with those after infusion via the femoral vein. Further, in an in vitro stability study and an in situ loop absorption study, FK506 was fairly stable in the gastrointestinal juice and was absorbed predominantly from the upper part of the small intestine.

Administration, Oral↗
PubMed1993

Craniofacial morphology of adolescent mandibular prognathism.

Morphological features of the craniofacial complex during orthopedic chin cup therapy were investigated in growing patients with mandibular prognathism. Lateral cephalograms of 30 subjects (15 boys and 15 girls, mean age: 9.04 +/- 1.29 years), taken at four different stages during treatment, were analyzed for 14 measurements. These measured values were standardized by use of Japanese controls and then evaluated to investigate longitudinal changes in the craniofacial morphology at the four different stages. Further, factor analysis was used to compare factors describing the craniofacial morphology for the initial and final stages. Dimensional changes of the mandible were not easily produced even if orthopedic treatment was conducted, whereas the maxilla exhibited a tendency to approach the normal range of the controls. Positional changes of the complex, the backward and downward repositioning of the mandible in particular, played an important role in altering a profile from prognathic before treatment to orthognathic at the end of treatment. Craniofacial morphology was similar pretreatment and posttreatment, although the orthognathic factor became more prominent when associated with positional changes of the mandible at the end of treatment.

Adolescent↗
PubMed1993

[Clinical efficacy of flomoxef in neonatal bacterial infection].

One hundred and seventy one neonates were treated with flomoxef (FMOX) and the clinical efficacy and safety were evaluated. The ages of the patients ranged from 0 to 28 days, and their body weights from 450 to 4300 g. Dose levels were 12.4 to 24.9 mg/kg every 8 or 12 hours for 1 to 10 days. Fifty two patients who responded to the FMOX treatment included 5 neonates with sepsis, 17 with suspected sepsis, 9 with urinary tract infections, 12 with pneumonia, 8 with intrauterine infections, and 1 with omphalitis. The other neonates could not be retrospectively diagnosed as bacterial infections. Of 52 patients, clinical results were excellent in 15, good in 34, fair in 1, and poor in 2. And the FMOX treatment was effective in 13 out of 14 patients in which causative bacteria were identified. The drug was well tolerated, but 6 neonates out of 33 over 5 days old had diarrhea. From these results, empiric treatment with FMOX against neonatal bacterial infection was as clinically useful as that of combination with ampicillin and gentamicin or cefotaxime and ampicillin in our neonatal intensive care unit. But, as this study did not include neonate with meningitis, efficacy to meningitis was not evaluated.

Ampicillin↗
PubMed1993

[Brain stem encephalitis due to Mycoplasma genitalium].

A 5 years old girl is described with infection due to Mycoplasma genitalium causing brain stem encephalitis. The diagnosis was established by polymerase chain reaction assay of the cerebrospinal fluid which demonstrated DNA of Mycoplasma genitalium. She was somnolent, had left abducens nerve palsy, and aphasis. The T2 weighted scan showed high signal intensity of pontine in magnetic resonance imaging (MRI) of the central nervous system. She recovered and was discharged without any sequelae.

Brain Stem↗
PubMed1993

An enzymological profile of the production of lactic acid in caries-associated plaque and in plaque formed on sound surfaces of deciduous teeth.

Specific activities of lactate dehydrogenase (LDH) and its fructose 1,6-bisphosphate (FBP) dependency in the small amount of plaque formed on deciduous teeth were determined and compared between those from carious lesions and from sound surfaces. Although the caries-associated plaque showed a higher production of lactic acid than the plaque formed on sound surfaces, it occurred only when sufficient FBP was present. The proportion of activity of FBP-dependent LDH relative to that of total LDH varied much more in the caries-associated plaque than in the plaque formed on sound surfaces. Hence, the varying activity of FBP-dependent LDH might be a distinguishing feature of caries-associated plaque compared with plaque formed on sound surfaces.

Child↗
PubMed1993

Cell-attachment activities of surface immobilized oligopeptides RGD, RGDS, RGDV, RGDT, and YIGSR toward five cell lines.

Tetrapeptides, Arg-Gly-Asp-Ser (RGDS), Arg-Gly-Asp-Val (RGDV), and Arg-Gly-Asp-Thr (RGDT), respectively, appearing in the cell-attachment domains of fibronectin, vitronectin, and collagen, and pentapeptide Tyr-Ile-Gly-Ser-Arg (YIGSR) appearing in B1 chain of laminin, were synthesized by liquid-phase procedure. Bioactivities of RGD, RGDX (X = S, V and T), YIGSR, and YIGSR-NH2 as cell recognition determinants were investigated by cell-attachment test using these oligopeptides immobilized to ethylene-acrylic acid copolymer (PEA) film. The cell lines used were A431, NRK, CHO-K1, HeLa.S3, and RLC-16 cells. It was found that the residue X in RGDX plays an important role for cell-attachment activity of RGDX, and, regarding YIGSR, introduction of NH2 residue at the C-terminal of the pentapeptide enhances the cell-attachment activity.

Acrylic Resins↗