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Biomedical subjects

T Yoshii

Publications and source records attributed to T Yoshii.

At least 55 records · Page 3Linked to original sources
PubMed1994

Polymerase chain reaction (PCR)/single-strand conformation polymorphism (SSCP) analysis of the human HLA-DQB regions.

Genetic diagnosis of 13 alleles of HLA-DQB1 (0501, 0502, 5031, 5032, 0601, 0602, 0604, 0201, 0301, 0302, 3032, 0401 and 0402) from 65 human DNA samples was achieved by applying single-strand conformation polymorphism (SSCP) analysis to DNA fragments amplified by the polymerase chain reaction (PCR) using a convenient primer set for DQB1 (recommendation of the International Histocompatibility Workshop, 1991). Differences between strand images (narrow/distinct or broad/diffuse) from the individual alleles and their electrophoretic mobilities are regarded as criteria for confirming the genetic diagnosis of DQB1 alleles. This primer set amplifies not only DNA fragments belonging to DQB1, but also to DQB2, and classification of 3 phenotypes (1.1, 1.2 and 1.1/1.2) in the presence of two alleles at the latter locus was suggested. Consequently, PCR/SSCP of DNA amplified by this primer enables classification of the phenotypes, at least under our experimental conditions, into 3 x 91 groups. Two advantages of SSCP analysis over VNTR with regard to the use of amplified DNA in forensic practice are described.

Alleles↗
PubMed1994

Bone mineral density of lengthened rabbit tibia is enhanced by transplantation of fresh autologous bone marrow cells. An experimental study using dual X-ray absorptiometry.

Autologous bone marrow cells were transplanted into the primitive callus in the lengthened tibia in young and adult rabbits. Bone mineral density (BMD) in the lengthened callus was evaluated using dual-energy x-ray absorptiometry. Basal BMD in the lengthened callus in the young rabbits was higher than that in the adult rabbits (p < 0.001). Transplantation of fresh suspended bone marrow cells increased the BMD in the young (p < 0.01) and adult (p < 0.001) groups. In the young rabbits, lysate of the bone marrow cells decreased the BMD (p < 0.005). Transplantation of cultured colony-forming cells or of separated multinucleated marrow cells did not increase the BMD. The authors' study indicates that the osteogenesis of the lengthened rabbit tibia is enhanced by transplantation of fresh autologous bone marrow cells.

Absorptiometry, Photon↗
PubMed1993

Effects of flunarizine and diltiazem on physical dependence on barbital in rats.

The effects of flunarizine and diltiazem both on development of physical dependence on barbital and on barbital withdrawal signs in rats were examined using the drug-admixed food (DAF) method. Rats were chronically treated with barbital or barbital in combination with flunarizine (fixed at 1.5 mg/g of food) or diltiazem (fixed at 0.75 mg/g of food)-admixed food on the schedule of gradually increasing doses of barbital. Motor incoordination during the treatment was potentiated by coadministration of flunarizine, but not by coadministration of diltiazem. After the termination of drug treatment, the body weight loss and withdrawal scores were significantly suppressed in the group coadministered flunarizine, but not in that coadministered diltiazem. There were no significant differences in plasma barbital levels after the withdrawal between groups. In the substitution test, flunarizine (20 and 40 mg/kg, IP) significantly suppressed the body weight loss and withdrawal scores after the withdrawal, but diltiazem (20 mg/kg, IP) did not. These results indicated that flunarizine suppressed both the development of physical dependence on barbital and barbital withdrawal signs, mainly according to the suppression of convulsions, but not diltiazem, which is known to poorly penetrate into the brain. Therefore, the present findings suggest that central calcium channels may be involved in both the development of physical dependence on barbital and the appearance of barbital withdrawal signs.

Animals↗
PubMed1993

[Water-soluble eumelanin as a PCR-inhibitor and a simple method for its removal].

It has been confirmed that water-soluble eumelanins often extracted together with DNAs from natural black hairs act as an inhibitor of Taq DNA polymerase in the polymerase chain reaction (PCR). In the present investigation, an attempt to amplify the non-coding 333-bp region of mitochondrial DNA (mt333DNA) produced the following results: 1) Water-soluble preparations made from chemically synthesized melanin (Sigma products), as well as natural black eumelanins, inhibited the PCR amplification of mt333DNA at concentrations of more than 2 micrograms/ml. 2) Quantitative measurement of Taq DNA polymerase-catalyzed DNA synthesis in terms of the amount of [alpha-32P] dCMP incorporated into activated calf thymus DNA showed that both of the water-soluble melanins had the same inhibition activity as represented by the sigmoidal curve derived from a quadratic equation of melanin concentration. This observation suggested that Taq DNA polymerase combined with two molecules of melanin to form an inactivated complex. 3) Melanins did not appear to affect either the thermostability of Taq DNA polymerase at 94 degrees C, or the step of primer-annealing to template DNAs. On the other hand, we established a simple and useful method for removal of water-soluble eumelanins contaminating DNA preparations from hairs. The method was based on the adsorption of melanins to Bio-Gel. When a Bio-Gel P-60 minicolumn was equilibrated with 10 mM sodium acetate buffer, pH 4.2, water-soluble melanins were completely adsorpted to it whereas DNAs passed through, although the melanins showed incomplete adsorption to the gel when it was equilibrated with TE (10 mM Tris-HCl, pH 7.5, 0.1 mM EDTA).(ABSTRACT TRUNCATED AT 250 WORDS)

DNA, Mitochondrial↗
PubMed1992

Genetic differences in the development of physical dependence upon diazepam in Lewis and Fischer 344 inbred rat strains.

The purpose of the present study was to investigate physical dependence upon diazepam systematically in two inbred strains of rats, Lewis (LEW) and Fischer 344 (F344). Rats were chronically fed food containing diazepam on an escalating drug dosage schedule, from 1 and 2 to 12 mg/g of food, over a period of 30 days. During treatment, the growth curve in LEW and F344 rats was suppressed compared with the respective controls. Motor incoordination was evaluated by a rotarod performance test. The ranking of the motor incoordination during the final concentration of diazepam was as follows: F344 greater than LEW. After substitution of normal food for the diazepam-admixed food, various signs of diazepam withdrawal occurred 16-120 h later. These signs included vocalization, irritability, muscle rigidity, ear-twitching, Straub's tail, piloerection, fascicular twitch, tremor, convulsion, and death. The incidences of vocalization, ear-twitching, piloerection, and tremor in F344 were significantly higher than those in LEW rats. Furthermore, two of six F344 rats showed spontaneous convulsions and one rat died of convulsions. Overall withdrawal scores were significantly greater in F344 (16.0) than in LEW (6.3) rats. These results suggest that diazepam withdrawal severity is strongly influenced by genetic factors, and F344 rats are highly susceptible to dependence upon benzodiazepines.

Animals↗
PubMed1992

Inhibitory effect of acylphloroglucinol derivatives on the replication of vesicular stomatitis virus.

The antiviral activity of natural phloroglucinols and of synthesized mono- and diacylphloroglucinols, and 2,6-diacyl-4,4-dialkylcyclohexa-1,3,5-triones was investigated. A correlation between the acyl chain length and inhibitory activity against vesicular stomatitis virus (VSV) was observed. Potent antiviral activity was found in di-isovalerylphoroglucinol. 2,6-Diacyl-4,4-dialkylcyclohexa-1,3,5-triones inhibited replication of the virus with low cytotoxicity.

Animals↗
PubMed1992

[Presence of a PCR-inhibitor in hairs].

A polymerase chain reaction (PCR) system was used to amplify the noncoding 333-bp region of mitochondrial DNA (mt333DNA) contained in DNA extracts from single human hairs, and the following results were obtained: 1) Using natural black hairs, mt333 DNA was always amplified from a 5-cm length of hair shaft sampled within a region 11 cm from the hair root, but it was not always amplified from a 5-cm region adjacent to this 11-cm region, and was not amplified in almost all cases when a 5-cm length of hair shaft was sampled from a region more than 16 cm distant from the hair root. DNA preparations not responding to PCR were colored dark brown. 2) Using natural white hairs, mt333DNA was amplified from almost all specimens even up to a length of 31 cm. 3) When natural black hairs were stained with an oxidation-type hair-staining agent (Bigen-5Ge), mt333DNA was never amplified even from the hair root portion, whereas the same staining treatment of white hairs did not influence the amplification of mt333DNA. In the cases showing no response on PCR, DNA preparations were also colored dark brown. 4) These dark brown DNA preparations inhibited completely the amplification of mt333DNA even after addition of purified DNAs. These results suggest that the dark brown substance in the DNA preparations inhibits the amplification of mt333DNA by the PCR method. We therefore investigated the mechanism responsible for the development of this inhibitor. It was found that hydrogen peroxide (a component of hair-staining agent) induced formation of water-soluble melanins from insoluble melanins.(ABSTRACT TRUNCATED AT 250 WORDS)

DNA, Mitochondrial↗
PubMed1991

Validation of single-photon emission computed tomography (SPECT) using thallium-201 in patients with lung cancer.

To evaluate the primary site, pulmonary hilar, and mediastinal lesions in patients with lung cancer, thallium-201 using single-photon emission computed tomography (SPECT) was used as a tumor agent. The study population consisted of 7 patients (5 men and 2 women), aged 57 to 82 years (mean 68). Tl-201 tomography imaged positive at the primary site in all patients with lung cancer. The images demonstrated the tumor and/or mediastinal lymph nodes that were greater than 2.0cm. In particular, each tomograms facilitated the identification of the Tl-201 increased uptake in proportion to primary site. The short waiting period after injection with Tl-201 clearly offers a major advantage over alternative tumor imaging agents, such as Ga-67 or radiolabeled monoclonal antibodies. Furthermore, Tl-201 SPECT may be useful to detect the tumor and/or mediastinal lymph nodes in patients with lung cancer.

Aged↗
PubMed1991

[Individual identification from extremely contaminated forensic specimens by sequencing cloned mitochondrial D-loop genes].

The PCR-amplified fragments of the human mitochondrial DNA were cloned, and independent clones were sequenced to identify individuals from trace amount of a composite forensic specimen originated from plural number of the individuals. The amplification of the mitochondrial DNA is suitable for forensic analysis where the specimens are highly degraded in most cases for its extremely high copy number and polymorphism as compared with the chromosomal DNA. And cloning procedure simplifies to correspond results to each individuals. Except three non-related individuals out of 34 cases analysed so far who gave identical sequence, the sequence in this segment were highly specific to each individuals and this procedure was extremely beneficial in individual identification from trace amount of highly contaminated and degraded forensic specimens.

Base Sequence↗
PubMed1990

Preference for cocaine by the weight pulling method in rats.

The purpose of the present study is to show the efficiency of the weight pulling method in evaluating quantitatively the positive reinforcing effect of cocaine. Rats were trained to pull the weight in order to eat the drug-admixed food (DAF). The experiments began with the preexposure of the drug through the repetition of CFF schedule. The schedule consisted of one choice trial (C) between the intake of normal food and DAF followed by two consecutive forced trials (F), in which the rats were forced to take the DAF only. The study consisted of Experiment I, where cocaine concentration in DAF was varied while the period of cocaine preexposure was kept constant and Experiment II, where the period of preexposure was varied while the cocaine concentration was kept constant. Results show that the reinforcing effect of cocaine was dependent on cocaine intake. On the other hand, the reinforcing effect of cocaine was independent of cocaine preexposure period. The effect of cocaine on the drug-seeking behavior was evident on the first day of cocaine exposure. It is concluded that the weight pulling method is sufficient to evaluate quantitatively the reinforcing effects of cocaine in rats, and this method may be useful for the prediction of dependence potential in man.

Animals↗
PubMed1990

Tc-99m RBC imaging for demonstrating intermittent intestinal bleeding.

A case of intestinal bleeding caused by multiple ulcerations near the terminal ileum is presented. Abdominal scanning with Tc-99m tagged red blood cells (Tc-99m RBC) demonstrated the intermittent bleeding in short intervals. Selective angiography did not demonstrate the bleeding site. Exploratory laparotomy showed 3 ulcers on the ileum at a site near the terminal ileum, with bleeding from one site. Tc-99m RBC abdominal scanning was very useful in this case for localization of the site of gastrointestinal bleeding before laparotomy.

Erythrocytes↗
PubMed1990

Epidemic acute haemorrhagic conjunctivitis due to Coxsackie virus A24 variant in Ghana.

An outbreak of acute haemorrhagic conjunctivitis (AHC) occurred in Accra, Ghana, reaching a peak in July 1987. Individuals ranging from infants to adults over 50 years were infected, with those between 20 and 30 years being the most affected group. There was a female preponderance. Clinical features included conjunctivitis, subconjunctival haemorrhage and ocular pain. Some patients reported of blurred vision due to mild keratitis. Isolation of virus from clinical specimens of AHC patients was successful only in cells of human origin such as HeLa and FL. Coxsackie virus A24 variant (CA 24v) was identified as the aetiologic agent. This is the first report to associate CA 24v with an epidemic of AHC in Africa, south of the Sahara, which is outside the endemic area of Southeast Asia and the Caribbeans. This finding suggests that earlier outbreaks of AHC in Ghana and Africa may have been due to CA 24v but went undetected. The results of various tests performed during this study suggest that, at least, two antigenically different viruses of CA 24v circulated during the course of this epidemic.

Conjunctivitis, Acute Hemorrhagic↗
PubMed1990

[The effects of constituents of an antitussive and expectorant preparation on physical dependence on and antitussive activity of dihydrocodeine].

The effects of constituents of an antitussive and expectorant preparation on physical dependence potential and antitussive activity of dihydrocodeine (DC) were studied. Rats were treated with DC, methylephedrine (ME), chlorpheniramine (CP), and caffeine (CA) singly or simultaneously admixed with food (DC 0.125, ME: 0.25, CP: 0.05, CA: 0.25 mg /g of food) for 7 days. Subsequently, rats were treated with naloxone (0.5 mg/kg, sc) and withdrawal signs produced were observed. Naloxone-precipitated body weight loss in DC-treated rats was suppressed by simultaneous administration of the three drugs (ME, CP and CA) or CP, which is a H1-receptor antagonist. In abrupt withdrawal, the withdrawal signs were also suppressed by CP. Moreover, tripelennamine, the same kind of H1-receptor antagonist, suppressed naloxone-precipitated withdrawal signs, but cimetidine H2-receptor antagonist, did not suppress them. These results may suggest that H1-receptor antagonists suppress the development of physical dependence on DC, and that H1-receptors play an important role in the physical dependence. On the other hand, the cough reflex was induced by electric stimulation in order to evaluate the influence of ME, CP, and CA on antitussive effect of DC in guinea pigs. ME enhanced the effect of DC. These experimental findings suggest that the constituents of the antitussive and expectorant preparation suppress the development of physical dependence on DC, though they increase the antitussive effect of DC.

Animals↗
PubMed1990

[Emergency perfusion lung scan for pulmonary embolism].

Six cases of pulmonary embolism were reported. As pulmonary embolism often becomes critical condition, early diagnosis and medical treatment is need. Perfusion lung scan for pulmonary embolism may be useful for a diagnosis and evaluation of the degree of its disease and therapeutic value.

Adult↗
PubMed1990

[Diagnosis of acute gastrointestinal bleeding using scintigraphy with 99mTc-labeled red blood cells].

To evaluate the usefulness and clinical significance of scintigraphy using 99mTc-RBC in urgent abdominal bleeding, we performed abdominal bleeding scintigraphy in 20 patients with melena. These patients were admitted to the critical care center. Nine of 20 patients showed positive images with bleeding scintigraphy. Five of 20 patients were referred because of small intestinal bleeding. Four of these 5 patients revealed positive images. Seven of 9 patients who had positive image and four of 11 patients who were negative had open-surgery performed. While angiography was done in 8 patients, only 3 of the 8 patients were proven to have bleeding. These 3 patients also revealed positive images by bleeding scintigraphy. This technique facilitates the screening of bleeding in the ileum, where endoscopic techniques may prove difficult to detect the site of bleeding. We emphasize that abdominal scintigraphy should be performed on patients with G.I. bleeding since this is a more accurate examination than angiography.

Adolescent↗
PubMed1989

Modification of the effects of naloxone in morphine-dependent mice.

Mice were rendered dependent on morphine by mixing morphine with their food (2 mg/g) for three days. Increasing doses of naloxone precipitated dose-dependent withdrawal reactions such as weight loss and jumping. These withdrawal reactions were antagonized by morphine pretreatment. Effects of morphine, such as increased locomotor activity, inhibition of intestinal transport, and analgesia were antagonized by naloxone in both non-dependent and dependent subjects. The antagonist actions of naloxone were increased in dependent subjects; lower doses of naloxone were sufficient to antagonize effects of morphine. The present results confirm earlier studies indicating that precipitation of withdrawal can be antagonized by morphine pretreatment suggesting that withdrawal reactions are due to actions of naloxone at the same receptor at which opioid agonists act. The increased antagonist potency of naloxone in dependent subjects extends earlier results obtained with analgesic effects to several other agonist effects of morphine and is consistent with the interpretation that exposure to an opioid agonist induces a change in the conformation of opioid receptors.

Analgesia↗