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Biomedical subjects

S Goto

Publications and source records attributed to S Goto.

At least 415 records · Page 23Linked to original sources
PubMed1995

Phosphatidylinositol responses are involved in the vascular effects of thiamylal and fentanyl.

Although thiobarbiturates potentiate, and fentanyl attenuates peripheral vasoconstriction, the intracellular mechanism involved in this phenomenon is not clear. Because smooth muscle contraction induced by alpha 1-adrenoceptor agonists is mediated by the phosphatidylinositol (PI) response, this study was carried out to clarify if thiamylal and fentanyl affect the norepinephrine-induced PI response in rat aortic slices. Rat aortic slices were incubated in Krebs-Henseleit solution containing 5 mM LiCl, [3H]myo-inositol, and varying concentrations of thiamylal or fentanyl. The Pl response was stimulated by 0.9 microM (ED50) norepinephrine (NE). The [3H]inositol monophosphate (IP1) was separated from [3H]myo-inositol by column chromatography and counted with a liquid scintillation counter. The basal IP1 accumulation was not affected by thiamylal and fentanyl. Norepinephrine-induced IP1 accumulation was potentiated by thiamylal at concentrations of 10 microM and 100 microM. Norepinephrine-induced IP1 accumulation was attenuated by 1 microM and 10 microM fentanyl. The results suggest that thiamylal stimulates the NE-induced PI response, which potentiates the vasoconstriction, and fentanyl attenuates NE-induced PI response, which would attenuate the vasoconstriction.

Anesthetics, Intravenous↗
PubMed1995

Suppression of gelatinase production with decreased invasiveness of choriocarcinoma cells by human recombinant interferon beta.

OBJECTIVE: Choriocarcinoma is a highly invasive gynecologic tumor, and hematogenous metastases frequently develop. To establish a molecular basis for antiinvasion therapy of choriocarcinoma, we examined the effects of human recombinant interferons on gelatinase production and invasion by choriocarcinoma cells. STUDY DESIGN: Using five choriocarcinoma cell lines, we measured gelatinase activity by gelatin zymography. The effects of recombinant interferons (rIFN-alpha, rIFN-beta, and rIFN-gamma) were then analyzed by Western blot analysis and chemoinvasion assay. RESULTS: High levels of 72 kd gelatinase activity were detected in the highly invasive choriocarcinoma cell lines, two of which also contained an active form of 72 kd gelatinase with an apparent molecular mass of 68 kd. Gelatinase production was decreased by incubation with rIFN-beta. In the chemoinvasion assay, only rIFN-beta had an inhibitory effect on the invasiveness of tumor cells without a cytotoxic effect. CONCLUSION: Choriocarcinoma cells showed high 72 kd gelatinase activity, which suggested a role for the enzyme in vascular metastasis. Studies on the use of rIFN-beta to inhibit metastasis of choriocarcinoma via suppression of gelatinase production are warranted.

Choriocarcinoma↗
PubMed1995

Central neurocytoma with hemorrhagic onset.

A case of central neurocytoma with spontaneous intraventricular hemorrhage is reported. A 23-year-old man, 2 years after experiencing intraventricular hemorrhage, developed severe headaches. The magnetic resonance image showed a mixed intense mass in the lateral ventricle with associated hydrocephalus. The tumor mass was totally removed. The tumor was histologically diagnosed as central neurocytoma. Review of the computed tomography taken 2 years ago showed not only the hemorrhage but also a mass in the left lateral ventricle. This emphasizes that central neurocytoma should be considered in the differential diagnosis of patients with either intraventricular hemorrhage or hemorrhagic tumor.

Adult↗
PubMed1995

Immunocytochemical localization of the striatal enriched protein tyrosine phosphatase in the rat striatum: a light and electron microscopic study with a complementary DNA-generated polyclonal antibody.

The present study concerns the immunocytochemical localization of the striatal enriched protein tyrosine phosphatase in the rat striatum. A novel molecular biology technique allowed us to produce a complementary DNA-generated polyclonal antibody raised against the non-catalytic domain of the striatal enriched protein tyrosine phosphatase, which selectively recognized the striatal enriched protein tyrosine phosphatase protein with 46,000 mol. wt on western blots. Immunocytochemical analysis with the specific antibody revealed strong striatal enriched protein tyrosine phosphatase immunoreactivity in the striatum. Light microscopy showed striatal striatal enriched protein tyrosine phosphatase-immunopositive neurons to be of medium size (mean diameter of 14.4 microns), and to comprise approximately 80% of the total neuronal population in the striatum. These cells had round, triangular or polygonal cell bodies with relatively little cytoplasm. Nerve fibers stained positively for striatal enriched protein tyrosine phosphatase were also present in the globus pallidus and the substantia nigra, and the nigral labeling on the ipsilateral side almost disappeared subsequent to cerebral hemitransection, suggesting these immunolabeled structures to be striatal projections. Double-immunofluorescence analysis demonstrated separate populations of striatal enriched protein tyrosine phosphatase-positive cells and neurons stained for parvalbumin. Also, ultrastructural study showed that the striatal enriched protein tyrosine phosphatase-positive neurons (n = 50) possessed no nuclear indentations or intranuclear inclusions. Thus, most striatal striatal enriched protein tyrosine phosphatase-positive neurons were thought to be of the medium-sized spinous type. At the light microscopic level, stained striatal neurons exhibited striatal enriched protein tyrosine phosphatase immunolabeling in their somata, dendrites and axonal processes, but not in their nuclei. Electron microscopic observation showed strong striatal enriched protein tyrosine phosphatase-immunoreactivity on the inner surface of the plasmalemma, on the outer surfaces of mitochondria and on microtubules, particularly of dendrites. A heavy deposit of immunoreaction product was also present on postsynaptic densities in labeled dendrites, while a light deposit was seen on the synaptic vesicles of nerve terminals. The characteristic distribution profile of striatal enriched protein tyrosine phosphatase suggested that the enzyme may play a role in a variety of functional properties of striatal neurons, especially in postsynaptic signaling processes and in regulation of microtubular functions. On the basis of the present findings, we propose the following conclusions: (i) a protein tyrosine phosphorylation system regulated by striatal enriched protein tyrosine phosphatase is involved in certain specialized cellular processes (e.g. signal transduction cascades) of medium-sized spinous neurons distinct from those of other neuronal subsets in the striatum; (ii) a striatal medium spiny neuron is characterized by its expression of striatal enriched protein tyrosine phosphatase and, therefore, the enzyme is useful for detection of the distinct subset of striatal cells or for tracing their axonal projection fibers in the basal ganglia.

Animals↗
PubMed1995

Isolation of a 40 kDa immunoinhibitory protein induced by rat liver transplantation.

In certain combinations of donor and recipient rat strains, such as DA (RT1a) donors into PVG (RT1c) recipients, rejection after orthotopic liver transplantation (OLT) is overcome without immunosuppressive drugs, although other organs transplanted between these combinations are promptly rejected. The mechanisms involved in achieving drug-free liver allograft tolerance still remain poorly understood. In the present study, OLT (DA into PVG) serum from various postoperative times was analysed by sodium dodecyl sulphate polyacrylamide gel electrophoresis and two unique proteins of 40 kDa and 37 kDa were found to be in large concentrations in 60 day post-OLT serum. These proteins could only be detected at specific times after OLT in the DA into PVG combination and could not be detected in the serum of syngenically transplanted animals (DA into DA) and (PVG into PVG), rejector combinations (DA into LEW) requiring immunosuppressive treatment or induced by other organ transplants. When these proteins were purified and sequenced they were found to have an identical N-terminal sequence which is not listed in sequence databases. Mixed lymphocyte assays revealed that only the 40 kDa protein has a immunosuppressive capability which additionally appears to be donor specific. The 40 kDa protein will aid further in the understanding of how drug-free tolerance is attained in certain liver allografts and may also act as a marker of when treatment with conventional immunosuppressive drugs can be stopped in clinical OLT providing a homologue of the molecule can be found. This possibility appears likely as case reports already exist of patients who have successfully been able to cease treatment with such drugs.

Amino Acid Sequence↗
PubMed1995

Augmentation of specific tumor killing activity by tumor-infiltrating lymphocytes (TIL) in the presence of TNF-SAM2.

The effect of TNF-SAM2 on cytotoxic activity of tumor-infiltrating lymphocytes (TIL) was investigated. TIL were prepared from 11 human cancer patients. They were propagated by double in vitro stimulation with anti-CD3 monoclonal antibody and interleukin-2, and cultured for 3 weeks. The cytotoxic activity of TIL was tested with standard 4h 51Cr-release assays in the presence or the absence of TNF-SAM2. In the presence of TNF-SAM2 (500U/ml), the mean cytotoxic activity against autologous tumor cells was significantly augmented compared to that in its absence. However, the fact that cytotoxic activity against K562 and Daudi showed no difference whether substance was present or not, indicates that LAK and NK activity were not affected by TNF-SAM2. Direct cytotoxicity by exogenously added TNF-SAM2 to tumor cells was measured in 9 out of 11 cases and this revealed that cytotoxicity solely by TNF-SAM2 was seen in 3 tumors. However, there was no correlation between the augmentation of cytotoxicity by TIL in the presence of TNF-SAM2 and the cytotoxicity shown by TNF-SAM2 alone. These results suggested that TIL therapy combined with administration of exogenous TNF may exert a synergistically stronger therapeutic effect on cancer.

Cytotoxicity, Immunologic↗
PubMed1995

Age-related accumulation of high-molecular-weight ubiquitin protein conjugates in mouse brains.

It has been demonstrated that the amount of ubiquitin (Ub)-protein conjugates increases in the whole brain homogenates of old mice. To determine the specificity of the accumulation of the conjugates, we further investigated age-related changes in Ub-protein conjugates in other tissues (heart, liver, and kidney), and also in various regions (cerebrum, cerebellum, brain stem, and medulla oblongata) of the brain. The amount of high-molecular-weight Ub-protein conjugates (HMW, > 60KDa) increased remarkably in all regions of the brain examined, especially in the cerebellum, of senescent mice, but not much in other tissues. No appreciable difference in the size of free Ub pool was found between young and old mice except in the medulla oblongata. This suggests that the increase in Ub-protein conjugates is not simply due to a rise in the free Ub pool. The activity of isopeptidases in homogenates was estimated by measuring rates of deubiquitination of endogenous Ub-protein conjugates under ATP-depleted conditions. In the brain stem and medulla oblongata, they decreased significantly with age. In the cerebrum and cerebellum, however, no significant difference was observed between young and old animals. These results partially explain the increases observed in medulla and brain stem, but cannot explain the increases in cerebrum and cerebellum.

Aging↗
PubMed1995

Characterization of serum proteins down-regulated by peroxisome proliferators: transient repression of apoE gene expression in the rat liver.

The effects of peroxisome proliferators on the levels of rat serum proteins were examined. The proliferators reduced the levels of several proteins in various ways with respect to proliferator-specificity and the time courses of the changes. The identification of three proteins by amino acid sequencing showed that they were functionally unrelated. This diversity suggests that several primary and secondary effects of the peroxisome proliferators caused the various changes in the levels of several serum proteins. Among these, apolipoprotein E was the most but transiently down-regulated by the two proliferators tested. Northern blots of the rat liver mRNA suggested that the primary step of the down-regulation was at pre-translation.

Amino Acid Sequence↗
PubMed1995

Cloning, sequencing, and expression in Escherichia coli of cDNA encoding porcine brain UMP-CMP kinase.

A cDNA encoding porcine brain UMP-CMP kinase has been isolated using two oligonucleotide probes synthesized on the basis of the partial amino acid sequences of the purified enzyme. The isolated cDNA consisted of 1,626 nucleotides including the coding region for a polypeptide of 196 amino acid residues with a calculated molecular weight of 22,279. The enzyme showed an overall sequence identity of about 40 and 50%, respectively, with adenylate kinases from mammalian muscle and Escherichia coli and UMP-CMP kinases from Saccharomyces cerevisiae and Dictyostelium discoideum. The two highly conserved residues, Thr-39 and Leu-66, in adenylate kinases, which are located close to the adenine ring of the bound AMP, are replaced by Ala and Ile, respectively, at the corresponding positions in UMP-CMP kinases. The entire structural gene was inserted 3'-downstream of the strong promoter in the expression plasmid pET-3b. E. coli BL21(DE3) cells carrying the resultant plasmid produced the active enzyme in a soluble state, most efficiently upon induction at 37 degrees C with 0.02 mM isopropyl-beta-D-thiogalactoside. The purified recombinant enzyme catalyzed specific phosphoryl transfer from ATP to UMP and CMP.

Adenylate Kinase↗
PubMed1995

Induction of the synthesis of hsp27 and alpha B crystallin in tissues of heat-stressed rats and its suppression by ethanol or an alpha 1-adrenergic antagonist.

The levels of hsp27 and alpha B crystallin in various tissues of rats that had been subjected to heat stress were determined by specific immunoassays. When rats were immersed in a water bath at 42 degrees C for 20 min, the levels of hsp27 in most tissues, including central nervous tissue, liver, lung, spleen, adrenal glands, and hypophysis, had increased dramatically 8 to 16 h after the treatment. alpha B crystallin was also induced at high levels in the liver and adrenals, but not much was induced in the central nervous tissue. The increases in the levels of both hsp27 and alpha B crystallin in response to heat stress were markedly inhibited when ethanol or an alpha 1-adrenergic antagonist, prazosin, was administered before, but not after, the stress period. The expression of mRNA for hsp27 was suppressed in the livers of rats that had received ethanol or prazosin. A beta-adrenergic antagonist, propranolol, and an alpha 2-adrenergic antagonist, yohimbine, did not inhibit induction of the synthesis of the two proteins. Accumulation of hsp70 after heat stress, at least in the liver, was inhibited by ethanol or prazosin in a similar manner to that of hsp27, as detected on Western blot analysis. These results suggest that the induction of hsp27 and alpha B crystallin, as well as of hsp70, in tissues of heat-stressed rats is controlled by a physiological process(es) that is sensitive to ethanol and prazosin, and is operative for a short time during the application of heat stress.

Adrenergic alpha-Antagonists↗
PubMed1995

Particle size studies for subcutaneous delivery of poly(lactide-co-glycolide) microspheres containing ovalbumin as vaccine formulation.

The primary objectives of the present study were to produce poly(lactide-co-glycolide) (PLGA) microspheres with different diameters, to characterize these microspheres which were loaded with a model antigen, ovalbumin and to evaluate the effect of microsphere particle size on the serum antibody levels following administration to mice. Four kinds of ovalbumin-loaded PLGA microspheres with different diameters (1.2, 3.5, 7.0 and 14.3 microns as mean volume diameter) were manufactured by a w/o/w emulsion/solvent evaporation method. Low loading percent (0.08%-0.25% w/w) and efficiencies (8-25% w/w) were observed. Examination using scanning electron photomicrographs showed smooth spherical particles. The in-vitro release of ovalbumin from microspheres showed an expected burst release with all batches and the extent of the burst release increased with decreasing diameters of spheres; PLGA microspheres with the smallest diameter (1.2 microns) showed an 80% burst release within one day. Approximately 10-60% of ovalbumin remained unreleased 30 days later. The single subcutaneous administrations of ovalbumin-loaded PLGA microspheres with different diameters to mice induced good antibody responses above ovalbumin saline negative controls at 3, 6, 9, and 12 weeks after inoculation. Especially, 0.16% ovalbumin-loaded PLGA microspheres having mean volume diameter of 3.5 microns exhibited the best immune responses with values greater than those obtained after inoculation with adjuvants such as complete Freund's adjuvant or alum as positive control. The strong adjuvant activity of PLGA microspheres as vaccine formulation was suggested.

Alum Compounds↗
PubMed1995

Transdermal delivery of theophylline using an ethanol/panasate 800-ethylcellulose gel preparation.

A novel ethylcellulose gel preparation using an ethanol/panasate 800 (tricaprylin) (40/60) binary lipophilic vehicle was developed and applied to the transdermal delivery of theophylline. The in vitro skin permeability of theophylline across excised hairless mouse skin was improved by the use of this ethanol/panasate 800 (40/60) binary vehicle compared with either ethanol or panasate 800 as a single vehicle, and the addition of lauric acid as a permeation enhancer to the binary vehicle shortened the lag time and increased the permeated amount of theophylline up to 6 h (initial permeation amount). The in vitro permeability of theophylline from the ethanol/panasate 800 (40/60)-ethylcellulose gels decreased with an increase in the content of ethylcellulose in the gels. In the in vivo evaluation using abdominal rat skin, the ethanol/panasate 800 (40/60)-7% (w/w) ethylcellulose gel produced a good feature as a sustained-release preparation, with a relatively high bioavailability (BA) of theophylline, and dose dependency was observed.

Administration, Cutaneous↗
PubMed1995

Optimization of preparative conditions for polylactide (PLA) microspheres containing ovalbumin.

Polylactide (PLA) microspheres containing ovalbumin (OVA) as a model protein were prepared by a water-in-oil-in-water (w/o/w) emulsion solvent evaporation method. The optimization of preparative parameters for the PLA microspheres containing OVA were performed, and the in vitro characteristics of the obtained microspheres were examined. Firstly, a smaller internal aqueous phase volume was found to be advantageous in obtaining high loading efficiency. Secondly, the addition of 2-10% (w/v) NaCl into the external aqueous phase (0.5% (w/v) polyvinyl alcohol solution) also improved OVA loading efficiency. Prepared products showed a sharp release of OVA at the initial phase, but the following phase was characterized by a slow release rate of OVA that continued at least 28 d. The release rate of OVA from microspheres made of PLA with a molecular weight of 15400 was faster than that from microspheres made of PLA with a molecular weight of 58300. However, the LA/GA (lactide/glycolide) ratio was not likely to have much effect on the release profile of OVA. Finally, the effect of PLA microsphere particle size on the release profiles of OVA was examined. The extent of burst release at the initial phase increased as the mean diameter of prepared PLA microspheres decreased. For example, the PLA microspheres with a small mean diameter (5.0 microns) showed a 40% burst release, but almost 30% of OVA remained in the PLA microspheres (confirmed by HPLC method) after the 28 d release test, suggesting the possibility of using this carrier as a long-acting protein delivery system.

Biocompatible Materials↗
PubMed1995

[Studies on development of pharmaceutical preparation with the purpose of improving controlled-release and bioavailability].

During the past fifteen years, the experiments based on three main propositions were proceeded to carry out in our laboratory, that is, (1) Microencapsulation: The method of solvent evaporation in water or oily phases was adopted because of its comparative simplicity in the procedure and its high reproducibility. The application of pharmacokinetic consideration to in vivo evaluation of microencapsulated drugs using beagle dogs intended for obtaining controlled-release by oral administration. The pullulan acetate phthalate microcapsules containing cefadroxil were prepared by the solvent evaporation method in liquid paraffin and showed a zero-order dissolution pattern in pH 6-7.4. (2) Rectal gel preparation: The hydrogels and xerogels were prepared by Eudispert hv. These gels have excellent staying properties in the lower part of the rectum, over a fairly long period. Eudispert hv hydrogels or xerogels containing propentfylline were tested for avoidance of the first-pass metabolism. The absolute bioavailability of propentofylline from gel preparations was almost 100%. (3) Binary vehicle for transdermal delivery: The effects of glycerides, short-chain alcohols and their binary vehicles as donor components on the skin permeation of ketoprofen across the excised hairless mouse skin were evaluated with the diffusion cell. Among single vehicles, Panasate 800 as lipophilic vehicle and ethanol as hydrophilic vehicle showed the effective permeation flux of ketoprofen. The greatest enhancement was observed in an ethanol/Panasate 800 (40/60) binary vehicle. The relationship between lipophilicity and skin permeability of 16 drugs from the ethanol/Panasate 800 (40/60) binary vehicle showed a parabolic shape with a peak at a more hydrophilic range compared with other past references.

Administration, Rectal↗
PubMed1995

Effect of long-term fluvoxamine treatment on endogenous serotonin uptake inhibitor-like substance in monkey cerebrospinal fluid.

We found that substances present in monkey cerebrospinal fluid (CSF) could inhibit [3H]-paroxetine binding in monkey brain preparations. The molecular weight of one of these inhibitory substances was approximately 2000, which is in agreement with earlier studies using human CSF. We also found that the inhibitory effect of the substances present in monkey CSF on [3H]-paroxetine binding decreased after 8 weeks of chronic fluvoxamine (5 mg/kg day, p.o.) treatment. These results suggest that the ability of a drug to decrease the activity of endogenous 5-HT uptake modulators may related to its antidepressive effects.

Animals↗
PubMed1995

Chlormadinone acetate as a possible effective agent for congenital adrenal hyperplasia to suppress elevated ACTH and antagonize masculinization.

We report two cases of congenital adrenal hyperplasia (CAH) in which administration of chlormadinone acetate (CMA), a substituted progestational agent for prostatic disease, suppressed ACTH hypersecretion and lowered plasma testosterone levels. Case 1 was 83-year-old male with advanced prostatic carcinoma and CAH due to 21-hydroxylase deficiency. His plasma testosterone did not decrease in spite of a bilateral orchiectomy. Case 2 was 40-year-old female with CAH due to 21-hydroxylase deficiency suffering from virilization after the cessation of cortisol supplement therapy because of her breast carcinoma. In these two cases, oral administration of CMA at a daily dose of 75-100 mg suppressed ACTH and cortisol to subnormal levels and reduced testosterone levels. With the suppressive effect on ACTH excess and antiandrogenic action, CMA may be suitable for patients with CAH suffering from symptoms due to overproduced ACTH or adrenal androgen.

Administration, Oral↗
PubMed1995

Primary hyperparathyroidism associated with multiple myeloma.

A 73-year-old woman was diagnosed as primary hyperparathyroidism. Hypercalcemia recurred after parathyroidectomy, though serum calcium concentration temporarily resumed to normal. Hypercalcemia was eventually shown to be due to multiple myeloma. In spite of the frequent association of hypercalcemia with malignant disease and the relative frequency of primary hyperparathyroidism as a cause of hypercalcemia, primary hyperparathyroidism accompanied by multiple myeloma has been considered in only a limited number of reports. Here, the cases in the literature are reviewed and discussed.

Adenoma↗