Biomedical subjects

Y Miwa

Publications and source records attributed to Y Miwa.

At least 127 records · Page 7Linked to original sources

PubMed1993

Promoter-independent catabolite repression of the Bacillus subtilis gnt operon.

The mechanism underlying catabolite repression in Bacillus species remains unknown. A recent study of the promoter-independent catabolite repression of the gnt operon implicated a consensus sequence (ATTGAAAG) in catabolite repression in the genus Bacillus. The introduction of base-substitutions into the ATTGAAAG sequence in the chromosomal gnt operon affected catabolite repression of the gnt operon. Deletion analysis indicated that the ATTGAAAG sequence is probably part of a cis sequence necessary for the promoter-independent catabolite repression of the gnt operon. Furthermore, we subjected gnt transcripts synthesized with and without glucose to S1 nuclease and slot blotting analyses. The results indicated that the gnt transcripts decreased in the region (+93 to +203; +1, the transcription initiation nucleotide) only in the presence of glucose. Mechanisms underlying this promoter-independent catabolite repression are discussed.

Bacillus subtilis↗

PubMed1993

Defective calcium-dependent signal transduction in T lymphocytes of ataxia-telangiectasia.

T-cell functions of two patients with ataxia-telangiectasia were investigated. Patients with ataxia-telangiectasia had reduced percentages of circulating CD3+ cells and CD4+ cells, although neither patient had a reduced percentage of circulating CD8+ cells. The proliferative responses and interleukin-2 production of peripheral blood mononuclear cells to T-cell mitogens were reduced in the patients. The intracellular calcium concentration in T cells or CD4+ cells from both patients was only slightly increased after phytohaemagglutinin stimulation. Moreover, the concentration after OKT3 stimulation was not or only slightly increased in T cells or CD4+ cells from both patients. Our results suggest that the functional defect of T cells is caused by defective Ca(2+)-dependent signal transduction through the CD3 complex of the surface in T cells of ataxia-telangiectasia.

Adolescent↗

PubMed1993

Encapsulation of chicken egg yolk immunoglobulin G (IgY) by liposomes.

Encapsulation of antibodies isolated from chicken egg yolk (IgY) in egg lecithin/cholesterol liposomes was attempted. IgY was successfully encapsulated into the liposomes by using the dehydration-rehydration method. Electron microscopic observation demonstrated that the liposomes prepared by this method were large multilamellar vesicles with a diameter of several microns. The encapsulation efficiency was improved by increasing the rehydration temperature to 60 degrees C. The cholesterol/lecithin ratio also affected the efficiency, giving the highest value at a ratio of 1/4 (mol/mol). Some efflux of glucose through the liposomal membranes was observed, particularly for the liposome with a low cholesterol content, but that of IgY was not detected, irrespective of the cholesterol content. Encapsulation reduced the activity loss of the IgY antibodies under acidic conditions. IgY encapsulated in the liposomes was also markedly resistant to pepsin hydrolysis, which usually results in complete loss of activity with unencapsulated IgY, suggesting that liposomal encapsulation is an effective means for protecting IgY under gastric conditions.

Animals↗

PubMed1993

Enzymatic synthesis of a novel trisaccharide, glucosyl lactoside.

Cyclomaltodextrin glucanotransferase from Bacillus stearothermophilus produced a series of oligosaccharides by the transglycosylation reaction with cyclomaltohexaose as a glycosyl donor and D-lactose as its acceptor. The content of oligosaccharide A as the main transfer product was 22.1% of the total sugar. The content was increased to 34.1% by hydrolysis with glucoamylase. Oligosaccharide A was isolated by column chromatography and crystallized. By chemical and enzymatic analyses, oligosaccharide A was found to be a novel non-reducing trisaccharide; O-beta-D-galactopyranosyl-(1-->4)-O- beta-D-glucopyranosyl alpha-D-glucopyranoside.

Carbohydrate Sequence↗

PubMed1993

[The enhancement of the chemotherapeutic effects on human prostate cancer cell--the combination with the growth factor interaction inhibitor (suramin)].

The present study was designed to evaluate the antiproliferative effects of suramin and the combination of suramin plus cisplatin (CDDP) on the hormone-independent human prostate carcinoma cell line (PC-93). In vitro, suramin induced a dose-dependent reduction of PC-93 proliferation, and at the clinically achievable concentration (300 micrograms/ml), suramin induced a 19.7% decrease in proliferation on the 3rd day compared to suramin-free control (P < 0.01). However, from the 4th day on the inhibitory action of suramin was reversed following exposure. The suramin-cisplatin combination showed an additive effect (inhibition ratio 32.4% on the 3rd day), and prolongation of the inhibition activity on the 4th day on, but it did not show any synergistic effect. Suramin inhibited dose-dependently the growth stimulatory effect of exogenous epidermal growth factor (EGF). In vivo study, suramin and suramin-cisplatin combination showed antitumor effects continuously in nude mouse implanted PC-93. These findings suggest that the inhibitory effects of suramin on PC-93 are mediated by inhibition of the EGF-mediated growth mechanism, but by a cytostatic rather than cytotoxic manner in vitro. In addition, other mechanisms such as inhibition of angiogenesis factor might exist in vivo.

Animals↗

PubMed1993

Defective calcium-dependent signal transduction in B lymphocytes of a certain common variable immunodeficiency.

Two different common variable immunodeficiency patients were studied. Patient 1 showed hypogammaglobulinemia in all major classes of gammaglobulins and slightly reduced percentages of circulating CD19+ cells, CD20+ cells and surface IgG-or IgA-bearing cells with a normal percentage of surface IgM-bearing cells. Patient 2 showed normal levels in IgM with IgG and IgA deficiencies and almost normal percentages of circulating CD19+ cells, CD20+ cells and surface IgM-, IgG- or IgA-bearing cells. The proliferative responses of peripheral blood mononuclear cells to B cell mitogen, Staphylococcus aureus Cowan I, were reduced in patient 1 but not in patient 2. The intracellular calcium concentrations in lymphoblastoid cell lines (LCLs) transformed by Epstein-Barr virus from patient 2 were increased after anti-mu stimulation. The concentrations were scarcely increased in LCLs from patient 1. These results suggest that B cells of patient 1 have a defective Ca(2+)-dependent signal transduction pathway, resulting in a failure of cell activation and cell proliferation. The defect in B cells of patient 2 may exist on immunoglobulin gene switching or expression rather than the Ca(2+)-dependent signal transduction pathway.

Agammaglobulinemia↗

PubMed1993

[Cavernous angioma in the cerebellopontine angle: a case report].

A rare case of cavernous angioma (CA) in the cerebellopontine angle (CPA) is reported. A 60-year-old female suffered from a right progressive sensorineural hearing loss and a successive right facial paresis over 2 years. A small mass was detected in her right CPA on CT scans. Both T1- and T2-weighted MR images demonstrated an intracanalicular lesion protruding into the CPA as being hyperintense. A small red colored lobulated tumor involving the 7th and 8th cranial nerves was found in the CPA through the suboccipital approach. The tumor contained multiple small hematomas in various stages. Biopsy with evacuation of these hematomas was selected to avoid damaging the cranial nerves. Histological examination of the specimen disclosed it as CA. Postoperatively her facial paresis improved slightly, but her hearing loss remained unchanged. Discussions were carried out concerning clinical and neuroradiological features of CA in the internal auditory canal and CPA. The present case and a previously reported 17 cases were the subjects under discussion.

Cerebellar Neoplasms↗

PubMed1992

5-HT3 receptor antagonists. 1. New quinoline derivatives.

A series of esters and amides of 1-alkyl-2-oxo-1,2-dihydroquinoline-4- carboxylic acid or 2-alkoxy-quinoline-4-carboxylic acid containing a basic azabicycloalkyl moiety has been synthesized and evaluated for affinity for the [3H]quipazine-labeled 5-HT3 receptors. Most of the esters exhibited 10-fold more potent activity than that of ondansetron (1; Ki = 7.6 nM). Lipophilic substituents at the 1- or 2-position of the quinoline ring enhanced affinity for the receptors. Compounds 21 and 37 showed the highest affinity (Ki = 0.32 and 0.31 nM, respectively) among them. On the other hand, most of the amides showed 100-fold lower affinity than that of the esters. Molecular modeling studies indicated that the carbonyl moiety in 19 (ester) or 31 (amide) was not coplanar to the plane of an aromatic ring (over 20 degrees deviation). Although some of the selected compounds exhibited potent activity in the Bezold-Jarisch (B-J) reflex test, good correlation was not observed between the affinity for the 5-HT3 receptors and the activity in the B-J reflex test (in vivo). From these data, it was suggested that our quinoline derivatives might interact with the 5-HT3 receptors in a different way from that of the reported 5-HT3 receptor antagonists presumably due to the presence of the heterogeneity of the 5-HT3 receptors between brain and heart.

Animals↗

PubMed1992

MRI demonstration of Kernohan's notch: case report.

We report a left acute subdural haematoma caused by rupture of a left anterior cerebral artery aneurysm, which progressed to left hemiparesis. Coronal MRI was superior to CT for visualizing Kernohan's notch.

Acute Disease↗

PubMed1992

Lymphocyte responses to food antigens in food sensitive patients with allergic tension-fatigue syndrome.

Scores of radioallergosorbent test (RAST) for cow's milk or buckwheat flour and proliferative responses of peripheral blood mononuclear cells (PBMCs) to bovine serum albumin and beta-lactoglobulin or buckwheat flour were measured in cow's milk or buckwheat flour sensitive patients with allergic tension-fatigue syndrome. In all 3 cow's milk sensitive patients with allergic tension-fatigue syndrome, RAST scores for cow's milk were negative or slightly positive, but PBMCs well responded to bovine serum albumin and beta-lactoglobulin, but not to ovalbumin. In a buckwheat flour sensitive patient with allergic tension-fatigue syndrome, RAST scores for buckwheat flour were negative, but PBMCs well responded to buckwheat flour, but not to ovalbumin, bovine serum albumin and beta-lactoglobulin. Conversely, in cow's milk or buckwheat flour sensitive patients with immediate allergic symptoms, RAST scores for offending foods were positive although PBMCs did not respond to offending food antigens. These results suggest that proliferative responses of PBMCs to food antigens are very useful for detection of offending foods in allergic tension-fatigue syndrome.

Adolescent↗

PubMed1992

Estimation of right ventricular volume by modified echocardiographic subtraction method.

To evaluate the accuracy and clinical utility of right ventricular volume estimated by a modified echocardiographic subtraction method versus Krebs' original subtraction method, an experiment was performed on hearts excised from 25 animals (dogs, pigs, and cows) followed by a clinical study of 41 patients with heart disease. Right ventricular volume was measured by subtracting the left ventricular volume from that of the whole heart based on echocardiographic apical two- and four-chamber views by means of the area-length method. In the animal heart study, the coefficient of variation between the right ventricular volume estimated by the modified method and the true volume was +/- 13%. The regression equation was y = 0.94x + 4.15 (r = 0.987, p less than 0.001) and showed good correlation, whereas the right ventricular volume obtained by the original method underestimated the true volume (coefficient of variation = +/- 25%, y = 0.59x + 1.11; r = 0.976, p less than 0.001). In the clinical study, the coefficient of variation between right ventricular volume estimated by the modified echocardiographic method and RV volume estimated by radionuclide ventriculography was +/- 15%. The regression equation was y = 0.80x + 13.3 (r = 0.935, p less than 0.001). This correlation was better than that obtained by the original method (coefficient of variation = +/- 16%), where the regression equation was y = 0.60x + 2.43 (r = 0.888, p less than 0.001). Thus the accuracy of the modified subtraction method was validated, and this method showed a better correlation than the original method both experimentally and clinically.

Adolescent↗

PubMed1992

Scoparic acid A, a beta-glucuronidase inhibitor from Scoparia dulcis.

The 70% EtOH extract of Scoparia dulcis showed inhibitory activity against beta-glucuronidase from bovine liver. Bioassay-directed fractionation of the active extract led to the isolation of three labdane-type diterpene acids, scoparic acid A [1] [6-benzoyl-12-hydroxy-labda-8(17), 13-dien-18-oic acid], scoparic acid B [2] [6-benzoyl-14,15-dinor-13-oxo-8(17)-labden-18-oic acid], and scoparic acid C [3] [6-benzoyl-15-nor-14-oxo-8(17)-labden-18-oic acid], the structures of which were established by spectral means, including X-ray analysis. Scoparic acid A was found to be a potent beta-glucuronidase inhibitor.

Acetylation↗

PubMed1992

[Clinical and epidemiological aspects of enteritis due to Salmonella hadar. I. Isolation of S. hadar from sporadic diarrhea--clinical and bacteriological study].

Before 1983, S. hadar was seldom isolated from man, animals, food or the environment in Japan: only one strain having been isolated from man and one from the environment. In subsequent years there has been a progressive increase in the number of isolations. S. hadar is now one of the commonest serotypes isolated from cases of sporadic diarrhea in Shizuoka Prefecture (Table 1). However, the epidemiology of S. hadar is not clearly understood. Reports on the clinical features of S. hadar gastroenteritis are also scarce. We examined the clinical symptoms of 15 cases of S. hadar gastroenteritis. S. hadar was encountered in patients of all ages. Infants and young children below 10 years of age constituted 47% of all cases. Seventy per cent of young children below 10 years of age experienced fever of more than 39 degrees C. This incidence was significantly higher than that of general Salmonella gastroenteritis observed in our previous study, in which fever of more than 38 degrees C was noted in 61% of the children. We found one case of presumptive person-to-person spread. No other household contacts of index patients suffered from diarrhea during the same period. Systematic examination for Salmonella contamination was performed for poultry farms, broiler chickens, broiler processing plants and meat on the market. 259 Salmonella strains were isolated from 1197 samples. S. hadar accounted for 37.1% (96) of all isolations (259). A drug resistance test was performed for 51 strains of the diarrhea cases and 67 strains of the environment. The pattern of the distribution of MICs of 9 drugs was similar in the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1992

[Clinical and epidemiological aspects of enteritis due to Salmonella hadar. II. Environmental contamination by Salmonella hadar in Shizuoka Prefecture--studies on the feasibility of reducing S. hadar infection].

A systematic examination was performed for environmental food contamination by Salmonella in poultry farms, broiler chickens, broiler processing plants and meat on the market. Salmonella was isolated from 219 of 1197 samples and the serotypes showed a wide distribution. (Table 1-1). S. hadar accounted for 37.1% (96) of all isolations (259). The contamination rate of broiler chickens on arrival at broiler processing plants is relatively low. However, in the broiler processing plants, containers, processing machinery, cooling water and slaughters were highly contaminated by Salmonella, S. hadar being the most prominent serotype in the plants. 64% of chicken meat on the market was contaminated by Salmonella, S. hadar being the second most prominent serotype. 11% of the pork and none of the beef or horseflesh was contaminated by Salmonella. These results indicate that poultry is the main source of S. hadar infection in humans. However, no S. hadar was isolated from cultures of 119 samples of feed for chickens from each delivery (Table 1-1). Thus, as the main source of infection by S. hadar of broiler chickens, an association with the feed seems to be ruled out. S. hadar was isolated at three of 18 poultry farms within Shizuoka Prefecture. Follow-up studies were performed at the three poultry farms which revealed that in two of them, Salmonella was completely eradicated on completion of disinfection. In the other one farm, which is still being disinfected, various strains of Salmonella including S. hadar still survived. We conclude that the main cause of the problem is the magnification of contamination of Salmonella-free material during the process at the broiler processing plants.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1992

Brain tumors manifesting as intracranial hemorrhage.

The clinical course and computed tomographic (CT) findings of 23 patients with brain tumors manifesting as tumoral hemorrhage were reviewed. The most common symptoms were headache and clouding of consciousness. A CT finding of a lesion located next to a solid or irregular clot indicated intratumoral hemorrhage. Precontrast CT demonstrating an indent on the hematoma surface was a valuable indicator of tumoral hemorrhage. A CT finding of accumulated levels of blood/fluid or a hyperdense mass containing small hematoma indicated intratumoral hemorrhage, and obscure hyperdensity indicated intratumoral hemorrhagic infarction. Such findings were often difficult to distinguish from spontaneous intracerebral hemorrhage due to other factors. The incidence of rebleeding from residual tumors was high, carrying a very poor prognosis, so radical removal of brain tumors with hemorrhage is very important.

Adolescent↗

PubMed1992

[The effect of ionized calcium concentration on muscle contraction and on the effect of non-depolarizing neuromuscular blocking agent].

The influence of serum ionized calcium (Ca2+) on the muscle contraction and on the effect of non-depolarizing neuromuscular blocking agent, d-tubocurarine (dTc), was investigated. The isolated phrenic nerve-diaphragma preparation of the rat was stimulated directly and indirectly at 0, 0.4, 0.7, 1.4, 2.5 mM of total calcium concentration (Ca2+: 0, 0.39, 0.52, 1.12, 2.32 mM, respectively). With indirect stimulation, no contraction was observed from 0 to 0.4 mM of calcium, but the twitch tension returned to 100 percent of control at over 0.7 mM of calcium. However, with direct stimulation, the twitch tension was obtained up to 100 percent of control independent of Ca2+ concentration. The ED50 of dTc was correlated well with the serum Ca2+. These findings suggest that the decrease of serum Ca2+ concentration interferes with the muscle contraction and potentiates the effect of dTc. We speculate that the site of its action may be primarily prejunctional.

Animals↗

PubMed1992

[Familial cavernous angioma of the central nervous system--report of a family and review of literature].

In this paper we reported a familially occurred cavernous angiomas (CA) of the central nervous system (CNS). Case 1 was a 14-year-old female with an initial symptom of transient motor and sensory disorders of the right upper extremity. On examination she had a cutaneous angioma and no neurological deficit. CT and MRI revealed two lesions in the brain. These lesions were removed surgically and were diagnosed histologically as CA. Case 2 was a 45-year-old female, the mother of case 1, with a long standing headache. She had a cutaneous angioma and no neurological deficit. CT and MRI revealed a CA in the brain and a one in the cervical cord. Case 3 was an 11-year-old female, the cousin of case 1, with an initial symptom of left hemiparesis. On examination, she had a cutaneous angioma and left hemiparesis. CT revealed two lesions in the brain. These lesions were removed surgically and were diagnosed histologically as CA. Familial CA of the CNS is relatively rare and the reported cases were 24 families consisted of 70 cases. We analyzed the reported cases to clarify the specificities of the familial cases. In the familial cases, CAs were apt to be multiple and were located more frequently in the posterior fossa than in the non-familial cases. In some familial cases, the vascular anomalies of the CNS other than CA or CA of the skin or retina were also revealed. Because of high incidence (89%) of the hemorrhage from the histologically verified CA, operation should be carried out even in the cases of CA with mild or no symptom, if the lesion is accessible surgically.

Adolescent↗

PubMed1991

Bacillus subtilis inositol dehydrogenase-encoding gene (idh): sequence and expression in Escherichia coli.

The Bacillus subtilis inositol dehydrogenase (Idh)-encoding gene (idh) was cloned in the B. subtilis temperate phage, rho 11, and then in Escherichia coli plasmids (pBR322 and pUC118). The nucleotide sequence of the idh gene, which consists of 344 codons and whose product has an Mr of 38,351, was determined. E. coli, bearing pIOL05d15, in which expression of the idh gene is under the control of the lac promoter of pUC118, overproduced an active Idh to approx. 20% of total protein upon addition of isopropyl-beta-D-thiogalactopyranoside. This overproduced enzyme cross-reacted with an anti-Idh antibody, and exhibited the same Mr and substrate specificity as those of the B. subtilis enzyme.

Amino Acid Sequence↗