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Biomedical subjects

S Tabata

Publications and source records attributed to S Tabata.

At least 199 records · Page 11Linked to original sources
PubMed1990

Purification of DNA ligases from mouse testis and their behavior during meiosis.

Two types of DNA ligase, I and II, have been purified approximately 4,000-fold from mouse testes and 500-fold from nuclei of mouse spermatocytes. DNA ligase I and II consisted of single polypeptides with molecular weights of 95,000 and 65,000, respectively, according to the estimation by SDS-polyacrylamide gel electrophoresis and the AMP-binding assay. Ligase activities were higher in premeiotic spermatogonia and spermatocytes than those in liver and bone marrow cells. Moreover, DNA ligase II showed rapid increase during meiotic prophase and a decrease in round spermatids. Since this behavior of DNA ligase II is consistent with that of m-rec and DNA polymerase beta, both of which have been shown to be involved in DNA recombination in meiotic cells, DNA ligase II might be an enzyme which works at the final step of meiotic recombination reaction.

Adenosine Monophosphate↗
PubMed1990

Studies on Fe complexes produced by yeast. V. Role of the ligand in Fe absorption from an Fe(II)-oligosaccharide complex.

The role of the ligand (oligosaccharide) of an Fe(II) complex (B1-c) produced in wine by Saccharomyces cerevisiae in gastrointestinal Fe absorption was examined. B1-c was found to consist of Fe(II) and an oligosaccharide having the composition of Ara: Xyl: Man: Glc: GalUA (1:1:1:5:1), and the sequence of these constituent monosaccharides was presumed by means of partial hydrolysis of B1-c with glycosidases and a diluted acid. The physicochemical comparison of the partially hydrolyzed, Fe(II)-containing products (Fe-containing fragments) obtained by glycosidase treatment indicated that the Man and GalUA residues of the ligand should be essential for stabilization of the complex form at the physiological pH in the digestive tract. The intestinal Fe absorption in vivo showed marked differences among the Fe-containing fragments having different ligands (sugar chains). Furthermore, the inhibitory effects of the Fe-containing fragments on B1-c uptake by brush border membrane vesicles of the small intestine varied with the ligand, probably being related to the composition of the sugar chain. These results suggest that the sugar chain of the ligand of B1-c may be involved, through its coordination with Fe(II), in (i) high stability and Fe solubility of B1-c at the physiological pH in the digestive tract and (ii) recognition of B1-c molecules in its transport system on the intestinal brush border membrane and, thereby, may contribute to excellent intestinal Fe absorption from B1-c.

Animals↗
PubMed1990

[Epidemiological and therapeutic study on gonorrheal infection--study on NY-198 (lomefloxacin) single administration therapy. Sapporo Clinical Research Group for STD].

The efficacy of single administration of NY-198 in the treatment of gonococcal infections was studied employing male patients with gonorrheal urethritis and female patients with gonorrheal cervicitis. The clinical efficacy was evaluated on the basis of the efficacy rates which was estimated on each observation day for each patient. In the male patients, NY-198 was administered in a dose of 200 mg in 25 cases and a dose of 400 mg in 65 cases. The rate of eradication of N. gonorrhoeae (i.e. efficacy) on the 3rd day of administration was 96% in the 200 mg administration group and 100% in the 400 mg administration group. On the 7th day after administration, the eradication rate was 100% in both the 200 mg and 400 mg administration groups. When the eradication rate on the 7th day was statistically estimated for patients who returned to the hospital only on the 3rd day, it was 97.9% in the 200 mg administration group. In the female patients, NY-198 was administered in a dose of 200 mg to 4 cases and a dose of 400 mg to 5 cases. The eradication rate on each observation day was 100% in both dosage groups. In conclusion, single administration of NY-198 in a dose of 200 mg or 400 mg was highly effective, and considered to be a therapeutic method highly useful clinically.

4-Quinolones↗
PubMed1990

Rapid conversion of the new angiotensin converting enzyme inhibitor ramipril to its active metabolite in rats.

The rate of conversion of ramipril (Hoe 498), a new angiotensin converting enzyme (ACE) inhibitor, to its active metabolite was compared with that of enalapril. After intravenous administration to rats, ramipril was very rapidly deesterified to its active moiety, ramiprilat. The ratio of the active metabolite level to the prodrug level in plasma at 5 min after administration was 10.7 for ramipril, which was about 5 times the ratio for enalapril. The in vitro conversion rates of ramipril were higher than those of enalapril in all rat tissue homogenates examined, including the liver, a main site of metabolism. The apparent Km values of ramipril and enalapril in the liver were 190 and 710 mumol/l, respectively, suggesting that ramipril has a higher affinity for esterase than enalapril. In conclusion, ramipril was superior to enalapril in efficiency of conversion to the active metabolite.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1990

[A case of alder (Alnus sieboldiana) pollinosis and its prevalence among the residents of a densely forested area].

The first patient with alder (Alnus sieboldiana Matsumura) pollinosis in Japan visited our clinic in April 1987. The patient was a 54 year old housewife who had lived in Kobe at the foot of Mt. Rokko since 1972, and had been suffering from the pollinosis for three years. In 1988, prevalence studies of A. sieboldiana in densely planted area close to the patient's house were performed using pollen count, immunological examinations and a population survey by questionnaire. A remarkably high prevalence rate of the pollinosis was demonstrated.

Adolescent↗
PubMed1989

Construction of an ordered cosmid collection of the Escherichia coli K-12 W3110 chromosome.

A cosmid library of the Escherichia coli K-12 W3110 chromosome was constructed in which clones were assigned to locations on the chromosome map by hybridization and genetic marker complementation tests. Approximately 70% of the genome was represented by this library. The identified clones can be maintained in the homologous system and would facilitate genetic studies of E. coli.

Chromosome Mapping↗
PubMed1989

Sequence determination and characterization of the replicator region in the tumor-inducing plasmid pTiB6S3.

The replicator region of the 195-kilobase-pair (kb) tumor-inducing plasmid pTiB6S3 was previously identified by isolation of a 6.8-kb miniplasmid (B.P. Koekman, P.J.J. Hooykaas, and R.A. Schilperoort, Plasmid 7:119-132, 1982). This miniplasmid was joined to ColE1-based vectors and subjected to mutagenesis. The resulting mutant plasmids were examined for their ability to replicate autonomously in Agrobacterium tumefaciens. It was found that a 4.2-kb region was sufficient for displaying replication characteristics similar to those of the parental pTiB6S3. Nucleotide sequence analysis of this 4.2-kb region revealed the presence of three possible reading frames in the same direction (repA, repB, and repC). Proteins coded for by these frames were identified by in vitro synthesis in a coupled transcription-translation system. The replicating ability became attenuated by repA and repB mutations but was completely abolished by repC mutations. The size, arrangement, and mutational effects of the three rep genes were quite similar to those of the rep genes that were previously identified in the hairy root-inducing plasmid pRiA4b. However, defects caused by rep mutations in one plasmid were unable to be complemented by corresponding functions in the other plasmid.

Amino Acid Sequence↗
PubMed1989

Plant saponins can affect DNA recombination in cultured mammalian cells.

Some plant extracts and products are known to affect mammalian cells, tissues and organisms as they contain a toxic substance or a metabolic stimulant. Our biochemical investigations revealed that some plant saponins can increase the cellular DNA repair activity and the general recombinase activity measured by in vitro assay (1). In the experiments described here, HeLa cells were cultured for several days with plant saponins or flavonoids and analyzed to measure i) recombination activity of the cell extract by induction of Tcr colonies from two mutant DNAs (mutants 1 and 2, which are both tetracycline sensitive) after transformation into E. coli recA-, and ii) repair synthesis of nuclear DNA followed by incorporation of 3H-thymidine. Saikosaponins a, b1, d, ginsenosides Rb1, Re, Rh and flavonoid baicalin caused a significant stimulation of intermolecular recombination. It is worth noting that none of the plant saponins and flavonoids had any inhibitory or toxic effect at concentrations less than 25 micrograms/ml in the culture media.

Animals↗
PubMed1989

Studies on Fe complexes produced by yeast. IV. Mechanism of Fe transport from an Fe(II)-oligosaccharide complex across the mucosal membrane of the rat intestine.

The mechanism of Fe transport across the rat duodenal membrane from an Fe(II)-oligosaccharide complex (designated B1-c) produced in wine by yeast and showing high hematopoietic activity in rats was examined. The Fe uptake from B1-c by brush border membrane (BBM) vesicles isolated from the rat intestine was based mainly on the Fe binding to membrane components which were suggested to be inside the vesicles. Evidence that Fe was transported into the vesicles by a special transport system other than simple diffusion was obtained by observing saturation kinetics under conditions of isotope exchange, and temperature and pH dependence. This Fe uptake was not inhibited by any metal ions tested, including inorganic Fe(II), and the BBM vesicles from the duodenum had a higher Fe uptake than those from the other parts of the small intestine. Furthermore, the BBM vesicles isolated from rats with Fe deficiency showed a significantly increased Fe uptake. The Km value for B1-c uptake was 0.16 mM, lower than the values for FeSO4 and ferrous ascorbate. These results suggest that a special transport system selective for B1-c may be present on the mucosal membrane. B1-c was taken up by the BBM vesicles in the form of Fe-oligosaccharide complex. From the preloaded vesicles, B1-c was released temperature- and pH-dependently.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

[Ganglioneuroma of the adrenal gland: report of a case].

A 38-year-old man was referred to our clinic with the complaint of upper abdominal discomfort. Ultrasonography and computerized tomography showed a mass occupying the left retroperitoneal space. Endoclinological results were within the normal range except for 17-OHCS and 17-KS. Preoperative diagnosis was left non-functioning adrenal tumor. Exploration was done via transperitoneal approach. The specimen weighed 100 g and was 11 x 6 x 5 cm in size. Histopathological diagnosis was ganglioneuroma of the left adrenal gland. There have been 35 reported cases with ganglioneuroma of the adrenal gland including our case in the Japanese literature and we reviewed the pathogenesis and treatment of this rare disease.

Adrenal Gland Neoplasms↗
PubMed1989

Pharmacokinetic study of cefodizime in experimentally infected animals.

Cefodizime, a new cephem antibiotic, was intravenously injected to mice with systemic or urinary tract infection by Escherichia coli and those with respiratory infection by Streptococcus pneumoniae, and the time courses of the plasma and tissue cefodizime levels were determined and compared with those in healthy mice (control group). In mice with systemic infection, the drug level in the plasma, liver, kidneys and lung changed on the basis of the two-compartment model. In this group, disappearance of the drug from plasma and tissues was obviously delayed and decrease in elimination constant (KE) and increase in the apparent volume of distribution (V2) were noted as compared with the control group. In the group with respiratory infection, T1/2(beta) and AUC for the hepatic drug level and T1/2(beta) for the renal drug level increased but in the other organs there was no great difference from the control group. In the urinary tract infection group, T1/2(beta) and AUC in the kidneys (infected site) and liver that mainly participate in elimination of cefodizime considerably increased differently from the control group. Changes of the distribution volume seemed to correspond with a physiological change of increase in body water content in the peripheral tissues (muscle, etc.) of the systemic infection group and in the liver, kidneys, etc. of the urinary tract infection group. Regarding the protein binding ratio, the urinary tract infection group showed a significant decrease as compared with the control group, but no distinct difference was noted in systemic and respiratory infections.

Animals↗
PubMed1988

The effect of temperature on recombination activity in testes of rodents.

An extractable enzyme system capable of catalyzing recombination in vitro was described in murine spermatocytes [Hotta et al. (1985) Chromosoma 93, 140-151]. The system is specific to meiosis, its activity increasing 400-fold between the premeiotic S-phase and mid-pachytene. The present study examines the effect of temperature on this system since the elevation of testicular temperature is one of the major factors causing impairment of testicular function. A strong depression of in vitro recombination activity occurred immediately after raising the testicular temperature in vivo by translocating the testes into the abdominal cavity (cryptorchid). The in vitro study also showed that the extract from spermatocytes preferred lower temperatures (30-32 degrees C) than somatic cells (37 degrees C) for maximal activity of recombination. These results suggest that the strong depression of recombination activity may be an important factor which causes degeneration of testes by heat.

Animals↗
PubMed1988

[A clinical study of genital herpes and the clinical efficacy of acyclovir tablets].

A clinical study for genital herpes was conducted on 154 patients and the efficacy of treatment with oral acyclovir was investigated in 51 of these patients. The diagnosis was confirmed by direct immunofluorescence or viral isolation from the lesion. This disease has increased in both males and females in recent years and was found in 2.3-2.9% of the out-patients examined in 1986. Seventy percent of the patients were between 20 and 30 years old. About 70% of the male patients had phimosis. In patients with the first infection, bilateral eruption (62%) and lymphadenopathy (54%) were more common than unilateral lesions. However, in those with recurrent infection, unilateral eruption (72%) and lymphadenopathy (52%) were more common. Sixty two percent of those with the first infection had scattered eruption on external genitalia, but 71% with recurrent infection, had lesions concentrated in several areas. Local symptoms such as pain in the external genitalia (male: female, 16%: 85%), pain in the lower extremities (26%: 45%), discomfort in the lower extremities (20%: 41%) and systemic symptoms such as malaise (22%: 48%) and anorexia (4%: 35%) were seen more frequently in females than in males. In addition, systemic symptoms such as fever (first episode: recurrent episode, 36%: 4%), malaise (34%: 9%) and anorexia (18%: 2%) were seen more frequently in patients with the first episode than in those with recurrence. HSV type 1 infections were found in 16% of males and 28% of females with the first episode, but were less common in the recurrent episode, 0% and 13%, respectively. Direct immunofluorescence was positive in 75 (59%) of 128 samples diagnosed by viral isolation. Treatment with oral acyclovir tablets, 200 mg five times daily, was very effective in 26 of 30 patients (87%). No side effects were observed. In this study, acyclovir tablet has been shown to be a very effective and well-tolerated treatment for genital herpes infections.

Acyclovir↗
PubMed1987

[Epidemiological and therapeutic studies on gonococcal infections--one shot therapy by spectinomycin--[Sapporo Clinical Research Group for STD]].

From January through March of 1985, the Sapporo Clinical Research Group for STD treated 69 cases of gonococcal infections (61 cases of male gonococcal urethritis and 8 cases of female gonococcal cervicitis) at its facilities in Sapporo City. The therapeutic efficacy of one shot therapy of Spectinomycin (SPCM) was investigated, and an epidemiological study on the cases and bacteriological studies on the isolated strains of Neisseria gonorrhoeae were made. The male patients were between 19 and 55 years old, with a peak age distribution in the younger half of the twenties. The female patients were between 18 and 40 years old. The major source of infections was a so-called special massage parlor which accounted for 36.1% of male cases. The isolation rate of PPNG were 16.7% (11/66). The MIC (inoculum size; 10(6) CFU/ml) of SPCM ranged from 3.13 to 25 micrograms/ml regardless of beta-lactamase production. In male patients, the eradication rate (efficacy rate) of N. gonorrhoeae by SPCM was 94.7% on the first day, 93.6% on the third day and 100% on the seventh day after 2 g one shot therapy. In female patients, the rate was 100% on the third and seventh day after 2 g one shot therapy, and 75% on the first day, 66.7% on third day and 100% on seventh day after 4 g one shot therapy. We considered that one shot therapy of SPCM was effective for gonococcal infection also in the present time. Especially SPCM was effective for infections by PPNG, since it was not resolved by beta-lactamase of N. gonorrhoeae. Positive rate of Chlamydia trachomatis was 16.3% in male gonococcal urethritis, and the serous discharge tended to remain longer in the positive patients than in the negative patients. There was only one side effect (1.4%), therefore SPCM was recognized to be a safely administrated antimicrobial agent.

Adult↗