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Biomedical subjects

S Inoue

Publications and source records attributed to S Inoue.

At least 793 records · Page 44Linked to original sources
PubMed1994

Ultrastructure of quick-frozen secretory ameloblasts of the rat molar tooth.

Ameloblasts in molar tooth germs from 4 to 12-day-old neonatal rats were quick-frozen and then freeze-substituted in acetone-tannic acid and acetone-osmium tetroxide. Following quick freezing and freeze-substitution, the preservation of ameloblasts was principally the same as seen in conventionally-fixed ones. Several differences, however, became apparent between two methods. Concerning enamel formation, the quick-freezing procedure greatly improved the preservation including that of the extrusion of secretory granules into the extracellular space. The exocytosis is a type of merocrine secretion. The precursor stippled material was demonstrated at the front of Tomes' processes and in the intercellular space of the distal terminal junction. In the more advanced stage, the stippled material tended to decrease gradually in amount. Prior to the formation of the typical Tomes' process, large secretory granules fused directly with the distal plasma membrane, which plays a role in the formation of prismless enamel. After the typical Tomes' process had formed, secretory granules containing electron-dense material instead of the large secretory granules accumulated in the distal portion of the Tomes' process. These latter secretory granules had two different destinations; i.e. the granules discharged their contents into the infoldings of the distal part of Tomes' process and into the infoldings of the lateral cell membrane. These types of secretion seem to have a functional role in the rod or inter-rod enamel formation. The ultrastructure of the stippled material consisted of 3-dimensionally interconnected strands after quick freezing, which is different from the appearance of granules embedded in amorphous material after conventional fixation. The stippled material was seen in the intercrystal space among the newly formed crystals. Also, an extensive tubulo-vesicular structure was preserved in both the cell body and Tomes' process. The present data suggest that the membrane of this structure showed a smooth contour opening to the extracellular space, and also an intimate relationship with the secretory granules.

Ameloblasts↗
PubMed1994

Usefulness of narrow pedicled intercostal cutaneous perforator flap for coverage of the burned hand.

A narrow pedicled intercostal cutaneous perforator (np-ICP) flap is used for reconstruction of hand scar contractures after burns. This flap is designed with a narrow pedicle which includes some intercostal cutaneous perforators of 4-7th intercostal spaces, and with a wide distal area which lies over the costal cage and upper abdomen. Additionally the flap is thinned until only the subdermal vascular network is preserved in most of the wide distal area. It seems that this flap is more useful, not only functionally but also aesthetically, than conventional methods. This report describes the technique and concept, with a demonstration of some clinical examples.

Adult↗
PubMed1994

Diabetes-induced reduction of neuronal survival in hypotonic environments in culture.

Dorsal root ganglion (DRG) neurons from streptozotocin (STZ)-induced diabetic and normal C57BL mice were exposed to three different hypotonic environments (1/2, 1/4, and 1/8 osmolar solutions). After rapid applications of these hypotonic solutions to the neurons, the cell volume autoregulatory mechanism operated in 1/2 osmolar solution but was disrupted in superhypotonic solutions below 1/4 osmolar in both kinds of mice. None of the neurons could survive 12 h after treatment with superhypotonic solutions. On the other hand, a gradual reduction of osmolarity of the culture medium enabled neurons in the normal mice to survive in 1/2 and 1/4 osmolar solutions as well as in an isotonic solution. However, this reduction of osmolarity increased neuronal cell death in the diabetic mice. These results suggest that the ability of DRG neurons to survive in hypotonic environments in culture may be lost in diabetes.

Animals↗
PubMed1994

Identification, developmental expression and tissue distribution of deaminoneuraminate hydrolase (KDNase) activity in rainbow trout.

A deaminoneuraminosyl-glycohydrolase (KDNase), which catalyses the hydrolysis of alpha-ketosidic 2-keto-3-deoxy-D-glycero-D-galacto- nononic acid (or naturally occurring deaminated neuraminic acid; KDN) linkages in KDN-glycoconjugates, is required for their structural and functional studies since KDN residues are usually resistant to the action of known sialidases. A search for KDNase was initiated by examining various cells and tissues of rainbow trout because KDN-glycoconjugates were first found in this animal species. Tissue localization studies of KDNase activity showed it to be present in kidney, spleen and ovary. The highest KDNase activity was found in ovarian post-ovulatory follicles obtained from female fish at the time when the reproductive organ was undergoing natural effacement. Little if any activity was found in brain, heart, liver, muscle, mature eggs and testis. Developmentally, higher levels of KDNase were usually expressed 3-4 months before ovulation or spermiation. An exception to this was in the ovary (or ovarian follicles) where the most striking increase in KDNase occurred 1-2 months after the maturation of gamete cells. Enzyme extracts containing KDNase activity also contained sialidase activity. From the data based on a kinetic study using mixed substrates, both KDNase and sialidase activities were indicated to reside on a single enzyme protein. The KDN-sialidase displayed broad specificity, which could possibly limit its usefulness as a probe for KDN-glycoconjugates. Nevertheless, unlike sialidases, KDNase can selectively remove KDN residues, thus making it an important new reagent to identify KDN-glycoconjugates in vivo.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1994

Occurrence and biological roles of 'proximal glycanases' in animal cells.

Glycosylation of particular proteins and lipids has become generally acknowledged as being important for these molecules to express their functions in various biological events. However, much less attention has been paid to the biological significance of deglycosylation of such once-glycosylated molecules in the context other than catabolism and recycling in the lysosome. Recently, in various kinds of animal cells and tissues we found non-lysosomal peptide: N-glycanase (PNGase) activities. Before these findings, PNGase was only known in plants and bacteria, and our findings indicated that de-N-glycosylation reaction catalysed by PNGase occurred universally in bioorganisms, and might function as a certain biologically important modification, not as a degradative pathway. Now, we put forward and extend the concept to all the glycoconjugates that deglycosylation as well as glycosylation occur as a universal cellular system to modulate the function of the present molecules, and postulate 'proximal glycanases' (PROXIases) as enzymes that are responsible for the detachment of intact glycan from glycoconjugates and form free glycan and apo-glycoconjugates. In this article, we review the occurrence and possible function of proximal glycanases in animal cells.

Amino Acid Sequence↗
PubMed1994

Role of Ca2+ in the binding of phospholipase A2 with a monomeric substrate and with its amide-type analog.

Effects of Ca2+ on the kinetic parameters for the hydrolysis of monodispersed 1,2-dihexanoyl-sn-glycero-3-phosphorylcholine (diC6PC), catalyzed by Group I phospholipases A2 (PLA2s) from Pseudechis australis, Naja naja atra, and bovine pancreas and by Group II enzymes from Vipera russelli russelli, Agkistrodon halys blomhoffii, and Trimeresurus flavoviridis, were studied by the pH-stat assay method at 25 degrees C, pH 7.5-8.2, and an ionic strength of 0.1 or 0.2 in the absence or presence of an amide-type substrate analog, 2-dodecanoyl-amino-1-hexanol-phosphoglycol. The binding of genuine substrate to the Group II enzymes and that of its analog to the Groups I and II enzymes were markedly facilitated by the binding of Ca2+ to the enzymes. On the other hand, the binding of genuine substrate to the Group I enzymes was found to be independent of the Ca2+ binding. The former result suggests that the structures of the Group II enzyme-genuine substrate complexes and both types of enzyme-analog complexes are generally stabilized by the Ca2+ binding, whereas the latter indicates that the structures of the Group I enzyme-genuine substrate complexes are already similar to those of their Ca2+ complexes and that, therefore, these enzyme-substrate interactions are independent of the Ca2+ binding.

Amides↗
PubMed1994

Antimetastatic effects of synthetic peptides containing the core sequence of the type III connecting segment domain (IIICS) of fibronectin.

The antimetastatic activities of synthetic peptides corresponding to fragments of the adhesion-related molecules, such as fibronectin and laminin, were examined. We prepared three peptides derived from the type III connecting segment domain (IIICS) of fibronectin: Glu-Ile-Leu-Asp-Val (EILDV), Glu-Ile-Leu-Asp-Val-Pro-Ser-Thr (EILDVPST), Arg-Glu-Asp-Val (REDV), and a laminin-related peptide, Tyr-Ile-Gly-Ser-Arg (YIGSR). Each peptide inhibited the experimental tumor metastasis of B16-BL6 melanoma, while EILDV had the strongest effect. The peptides conjugated with poly(ethylene glycol) (PEG) were more effective than the unmodified peptides in molar ratio terms. A mixture composed of PEG hybrids with EILDV, REDV and YIGSR significantly inhibited tumor metastasis.

Amino Acid Sequence↗
PubMed1994

Significant predictors for readmission of the severely mentally ill to a provincial hospital: is the efficacy of community care explicit or implicit?

The aim of our study was to determine the factors pertaining to the seriously mentally ill patients who were forewarned of readmission to a provincial mental hospital in Vancouver, British Columbia. It is well known that, compared to the psychiatric care delivery systems in Japan, Vancouver and its metropolitan area provide the seriously mentally ill with a much wider range of community mental health programs. Our sample was 161 first admission DSM-II schizophrenic patients to a provincial hospital, who had been followed for five years. A discriminant analysis showed that of the 11 predictive factors selected, such socio-cultural factors as living situations and country of birth were the most significant predictors.

Adolescent↗
PubMed1994

Dose-related protective efficacy of immunoglobulins in experimentally induced group B streptococcal infection.

This study investigates the dose-dependent effect of administration of commercially available intravenous immunoglobulins (IVIG) on the survival of newborn rats experimentally infected with group B streptococci (GBS). The opsonic activity of various concentrations of IVIG in vitro was determined by examination of opsonophagocytosis of GBS by peritoneal macrophages and bacterial killing by blood neutrophils. The best survival was observed in newborn rats who received immunoglobulins at doses of 250, 500 and 1,000 mg/kg of bodyweight. The survival of animals that received either 125 mg/kg or 2.5 g/kg of immunoglobulins was no better than that of animals who received no immunoglobulins. The maximal phagocytosis and bacterial killing were observed at in vitro immunoglobulin concentrations ranging from 32 to 250 mg/dL (these in vitro concentrations may correspond roughly to in vivo administration doses ranging from 150 to 1200 mg/kg). These doses are comparable to the doses of IVIG currently administered to neonates. However use of very high doses may be harmful to babies since the high concentration of non-specific immunoglobulins inhibited in vitro phagocytosis and bacterial killing by phagocytes.

Animals↗
PubMed1994

Long-term effects of bone marrow transplantation for inborn errors of metabolism: a study of four patients with lysosomal storage diseases.

Long-term effects of bone marrow transplantation (BMT) were evaluated in patients with I-cell disease, metachromatic leukodystrophy (MLD), Maroteaux-Lamy syndrome or Hunter syndrome (mild form). Donors were human leukocyte antigen (HLA)-matched siblings, and the follow-up periods were 24-71 months after BMT. The enzyme activities were increased in leukocytes, plasma or liver tissues compared with pre-BMT levels. A patient with I-cell disease acquired development of 4-8 month old infants and showed no further progression in cardiac dysfunctions. A patient with MLD showed a decelerated disease progression and an improved peripheral neuropathy, but progressive brain atrophy was not prevented. Patients with Maroteaux-Lamy syndrome or Hunter syndrome showed improvements in hepatomegaly, joint contractures, short stature and tight skin, and this greatly increased their quality of life. These results indicated that the long-term therapeutic effects achieved by BMT were subject to multiple factors including biochemical improvements, a reversibility of affected tissues, or advanced states of disease and central nervous system impairments in inborn errors of metabolism.

Adolescent↗
PubMed1994

The fluctuations of neuron-specific enolase (NSE) levels of cerebrospinal fluid during bacterial meningitis: the relationship between the fluctuations of NSE levels and neurological complications or outcome.

Neuron-specific enolase (NSE) is one of the glycolytic enzymes distributed exclusively in neurons. It was measured serially in the cerebrospinal fluid (CSF) of 10 children with bacterial meningitis during the illness using radio-immunoassay. The relationship between CSF-NSE levels and neurological complications or outcome was examined. CSF-NSE levels were significantly higher in the patients with bacterial meningitis than in the patients with the other central nervous system (CNS) infectious diseases, suggesting that CNS damage in those patients with bacterial meningitis was exacerbated. As CSF-NSE levels increased to above 25 ng/mL in the acute phase, all patients except one had subdural effusion. In those patients whose CSF-NSE level rose again during the illness, CNS complications or sequelae occurred. CSF-NSE may be a useful prognostic factor for predicting CNS damage in childhood bacterial meningitis.

Acute Disease↗
PubMed1994

Adsorption of human recombinant erythropoietin on dialysis membranes in vitro.

The adsorptive characteristics of 5 dialysis membranes for recombinant human erythropoietin (EPO) were studied in vitro in a closed circuit system. For 120 min, EPO added with bovine serum was significantly adsorbed by polymethylmethacrylate (PMMA) and polyacrylonitrile (PAN) membranes but not by Cuprophan, ethylene vinyl alcohol (EVAL), or polysulfone (PS) membranes. In addition the EPO adsorptive rate, as well as that of beta 2-microglobulin (beta 2-MG), was greater with a PMMA membrane than with a PAN membrane. EPO was not detected in the ultrafiltrate at 15 min with 5 membranes. These results indicate that EPO was eliminated by membrane adsorption only with some dialysis membranes.

Acrylic Resins↗
PubMed1994

Adenovirus pulmonary infections identified by PCR and in situ hybridisation in bone marrow transplant recipients.

AIMS: To investigate adenovirus pulmonary infections in bone marrow transplant (BMT) recipients. METHODS: Formalin fixed, paraffin wax embedded lung tissue was examined from 13 necropsy cases after BMT using PCR and in situ hybridisation to detect adenovirus DNA. The E1A region of the adenoviral genome was targeted for PCR. In situ hybridisation was performed only in the PCR positive cases. RESULTS: Of the 13 lung specimens analysed, nine cases were negative for adenoviral nucleic acid. Four (30%) PCR and two (15%) in situ hybridisation positive cases were found. In some of the patients there were clinical and pathological indications that some diseases might be associated with adenovirus infection--haemorrhagic cystitis (three cases); necrotising pneumonia (one case). In necrotising pneumonia in which no pathogenic agents had been shown by conventional histological study, the in situ hybridisation technique showed positive staining for adenovirus. In a patient who died of renal failure caused by adenovirus nephritis, both PCR and in situ hybridisation were positive in the lung as well as in the kidney, although no histological change was found. Two PCR positive cases lacked positive sites for adenovirus by in situ hybridisation. CONCLUSIONS: The combination of PCR and in situ hybridisation could be useful for diagnosing adenovirus infection of the lung in BMT recipients. These results provide a basis for exploring further the clinical use of PCR and in situ hybridisation to diagnose adenovirus infection.

Adenovirus Infections, Human↗
PubMed1994

Immunohistochemical and in situ hybridisation detection of adenovirus early region 1A (E1A) gene in the microglia of human brain tissue.

To investigate whether brain tissue is infected latently by adenovirus via a monocyte/microglia-mediated entry mechanism, brain tissue resected at necropsy from seven senile subjects (five with senile dementia of Alzheimer type (SDAT) and two subjects without pathological changes) was examined for adenovirus early region 1A (E1A) gene and its expression using in situ hybridisation and immunohistochemical staining. HLA-DR positive, reactive microglial cells in both SDAT and normal brain tissue showed positive hybridisation and immunoreactive expression of adenovirus E1A. Thus there may be monocyte/microglia-mediated entry of adenovirus in the central nervous system which would be a novel and presumably common interaction between brain tissue and adenovirus.

Adenoviridae↗
PubMed1994

Portal venous invasion by pancreatobiliary carcinoma: diagnosis with intraportal endovascular US.

PURPOSE: To evaluate use of intraportal endovascular ultrasonography (IPEUS) in diagnosing portal venous invasion by pancreatobiliary carcinoma. MATERIALS AND METHODS: IPEUS was performed in 26 consecutive patients with pancreatobiliary carcinoma. All patients underwent surgery. IPEUS was performed intraoperatively in 20 cases and preoperatively in six. The sonographic criterion for detection of portal venous invasion was obliteration of the echogenic band of the portal vein. The IPEUS results were compared with those of computed tomography (CT) and arterial portography. RESULTS: Vascular invasion was confirmed with use of resected specimens in seven patients and operative findings in five patients. For diagnosis of portal venous invasion, the sensitivity, specificity, and overall accuracy of IPEUS were all 100%; respective values were 92%, 64%, and 77% for angiography and 50%, 79%, and 65% for CT. CONCLUSION: IPEUS allows detection or exclusion of early invasion of the portal venous wall by pancreatobiliary carcinoma.

Aged↗
PubMed1994

Gastric damage and body weight loss in LHA-lesioned rats: effects of cytoprotective geranylgeranylacetone.

We investigated the development of gastric damage and body weight (BW) loss in lateral hypothalamic area (LHA)-lesioned rats, measured 2 h and 1 and 3 days after the lesioning (experiment 1), as well as the effects of geranylgeranylacetone (GGA), a cytoprotective antiulcer agent, on these disorders (experiment 2). In experiment 1, BW of LHA-lesioned rats decreased throughout the 3-day experiment. In LHA-lesioned rats, gastric mucosal lesions appeared 1 day after lesioning in the glandular portion and persisted, whereas those in the rumenal portion appeared only after 3 days. Gastric transepithelial potential differences (PDs) of glandular portion began to decrease after 2 h and had decreased in both portions. Gastric acid output was increased transiently at 2 h but it was not high after 1 day and after 3 days was lower than that in sham-LHA-lesioned rats. In experiment 2, PDs of the rumenal decreased more in LHA-lesioned rats than in sham-LHA-lesioned rats pair fed to LHA-lesioned rats after 3 days. Three days of treatment with GGA (200 mg/kg ip) improved PDs of rumenal and glandular portions in LHA-lesioned rats and reduced lesions of the rumenal portion. Loss of BW in LHA-lesioned rats was significantly but not completely inhibited by GGA. These results indicate that disturbance to the gastric defensive mechanism plays an important role in the development of gastric lesions after LHA lesions and that the impairment of gastric functions may be a partial cause of the loss of BW in LHA-lesioned rats.

Animals↗