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Biomedical subjects

K Hosaka

Publications and source records attributed to K Hosaka.

At least 73 records · Page 4Linked to original sources
PubMed1992

[A case of adenosquamous carcinoma with unknown origin and with superior vena cava syndrome as the first symptom].

This report is concerning a case of adenosquamous carcinoma having unknown origin and showing SVC syndrome as the first symptom. A 44 year-old man was admitted to our hospital because of facial edema at the beginning of April 1990. He was diagnosed as having a mediastinal tumor of the SVC syndrome type. Resection of the SVC tumor and part of the pericardium was performed on June 20, 1990. The operation had extraordinary findings. Lymph nodes adhering to tumor invaded the adjacent right side of the trachea and were situated in a rosette-like form. Furthermore, a part of the tumor stemmed into the lumen of the superior vena cava causing complete obstruction. The pathological diagnosis of the SVC tumor was adenosquamous carcinoma, however, no clinical examinations could identify its original matrix. Mediastinal tumors of unknown origin are reported as about 1% of all mediastinal tumors, and are responsible for 0.68% of all carcinomas in the mediastinum. This was one experience of a rare case of mediastinal tumor having unknown origin and showing SVC syndrome as the first symptom.

Adenocarcinoma↗
PubMed1991

Ion-sparing diuresis by 2,3-dibenzylbutane-1,4-diol, a synthetic mammalian-lignan derivative.

Diuretic properties of a synthetic lignan, 2,3-dibenzylbutane-1,4-diol (hattalin), and a naturally occurring arctigenin were examined in BALB/c male mice and Wistar male rats. Intra peritoneal administration of hattalin (50 mg/kg) in mice increased urine volume by 1.7-3.1 fold that of placebo-treated animals 40-260 min after administration (p less than 0.05 vs control). In contrast, 100 mg/kg of arctigenin had no effect on urine volume in mice. Hattalin (100 mg/kg), arctigenin (100 mg/kg), or furosemide (50 mg/kg) as a positive control was administered orally to rats, and accumulated urine volume was measured for up to 6-12 h. The urine volume of animals administered with hattalin showed 1.4-1.5 fold that of placebo-treated animals after 2-6 h of administration (P less than 0.05, n = 10). On the other hand, arctigenin showed no significant effect on urine volume for up to 12 h after administration (n = 8). The urine volume in animals administered with furosemide (n = 10) was 2.0-3.0 fold that of placebo-treated animals (P less than 0.01). Furosemide increased total Na+, K+, or Cl- excretion by 1.9, 1.8 or 2.2 fold, respectively, when compared with placebo-treated controls (P less than 0.01), whereas hattalin decreased Na+ excretion by 3.6 times (P less than 0.01), K+ excretion by 1.4 times (not significant), and Cl- excretion by 3.1 times (P less than 0.01). Serum Na+ and K+ levels did not change in both furosemide- and hattalin-administered rats, however, serum Cl- levels in these animals significantly decreased (P less than 0.01) when compared with controls. The results suggest that the diuretic property of hattalin is due to a novel mechanism which is different from that of furosemide or other diuretics modifying the ion-exchange at the uriniferous tubules.

Animals↗
PubMed1991

Functional analysis of the regulatory region of the yeast phosphatidylserine synthase gene, PSS.

The upstream region of the PSS gene contains three positive cis-acting elements, upstream activation sequences 1 and 2 (UAS1 and UAS2) and a TATA box. The 5' end of UAS1 occurs between positions -239 and -209, and that of UAS2 is between positions -172 and -164. UAS2 contains 5'-TTCACATG-3' as a core sequence at positions -161 to -154. Mutational analysis revealed that this octamer is responsible for the control of PSS expression by inositol and choline. The TATA box is located at positions -112 to -108. In addition, PSS contains a negative cis-acting sequence between UAS2 and the TATA box.

Base Sequence↗
PubMed1991

Expression in Escherichia coli of the Saccharomyces cerevisiae CCT gene encoding cholinephosphate cytidylyltransferase.

The coding region of the CCT gene from the yeast Saccharomyces cerevisiae was cloned into the pUC18 expression vector. The plasmid directed the synthesis of an active cholinephosphate cytidylyltransferase in Escherichia coli, confirming that CCT is the structural gene for this enzyme. The enzyme produced in E. coli efficiently utilized cholinephosphate and N,N-dimethylethanolaminephosphate, but N-methylethanolamine-phosphate and ethanolaminephosphate were poor substrates. Consistently, disruption of the CCT locus in the wild-type yeast cells resulted in a drastic decrease in activities with respect to the former two substrates. When activity was expressed in E. coli, over 90% was recovered in the cytosol, whereas most of the activity of yeast cells was associated with membranes, suggesting that yeast cells possess a mechanism that promotes membrane association of cytidylyltransferase.

Amino Acid Sequence↗
PubMed1991

Synthesis and protective effect of 1,3,5-triazine derivatives, leukotriene C4 antagonist, on HCl.ethanol-induced gastric lesions in rats.

2,4-Diamino-[E]-6-[2-(3-pyridyl)ethenyl]-1,3,5-triazine (3a), leukotriene C4 (LTC4) antagonist, was found to possess a protective effect on HCl.ethanol-induced gastric lesions. Analogues of 3a were synthesized and evaluated for the effect as well as antagonistic activity against LTC4-induced contraction. Seven compounds (3a-d, f-h) exhibited a potent protective effect on gastric lesions which was considered to be based on the antagonistic activity against LTC4. The structure-activity relationships of the derivatives (3a-k) are discussed.

Animals↗
PubMed1991

Identification of the upstream activation sequences responsible for the expression and regulation of the PEM1 and PEM2 genes encoding the enzymes of the phosphatidylethanolamine methylation pathway in Saccharomyces cerevisiae.

The yeast phosphatidylethanolamine methylation pathway is encoded by two structural genes, PEM1 and PEM2. The abundance of their transcripts was coordinately repressed by myo-inositol and choline. The most upstream transcriptional start sites for PEM1 and PEM2 were mapped at positions -142 and -42 relative to their first ATG codons, respectively. Promoter deletion analysis defined the 5' boundary of the regulatory region of PEM1 between -336 and -332 and that of PEM2 between -177 and -158. The 38-bp sequence between -336 and -299 from PEM1 and the 48-bp sequence between -177 and -130 from PEM2 conferred regulated transcription upon an upstream-activation-sequence-deficient test gene, CYC1-lacZ. Comparison of these two regions revealed the presence of a common octameric sequence, 5-CATRTGAA-3', which occurred twice in the 38-bp PEM1 regulatory region and once, followed by the 5'-AAACCCACACATG-3' GRFI site, in the 48-bp PEM2 regulatory region. When synthesized chemically and placed in front of CYC1-lacZ, a single copy of CATATGAA directed a rather low level of gene expression, but multiple copies produced high-level expression. In both cases, gene expression was sensitive to myo-inositol and choline. The synthesized GRFI site directed considerable but constitute lacZ expression. When used in conjunction with CATATGAA, synergistic, regulated gene expression was obtained. Hence CATRTGAA was concluded to play an important role in the myo-inositol-choline regulation of PEM1 and PEM2. Binding proteins to these sequences were demonstrated by electrophoretic mobility shift assay. Protein binding to CATRTGAA was not competitive with binding to the GRFI sequence, and vice versa. CATRTGAA was also found in the upstream regions of other genes encoding phospholipid-synthesizing enzymes, such as choline kinase, phosphatidylserine synthase, and myo-inositol-1-phosphate synthase, known to be repressed by myo-inositol and choline.

Base Sequence↗
PubMed1990

Primary structure of the yeast choline transport gene and regulation of its expression.

The yeast Saccharomyces cerevisiae possesses a choline transport system encoded by the CTR gene. Incorporated choline is exclusively utilized for the synthesis of phosphatidylcholine. Determination of the complete nucleotide sequence of the CTR gene showed that the deduced primary sequence of the choline transporter comprised 563 amino acid residues with a calculated molecular weight of 62,055. Both the amino- and carboxyl-terminal regions were hydrophilic whereas the rest of the sequence was highly hydrophobic and contained several membrane-spanning regions. There were four potential glycosylation sites in the hydrophilic parts of the sequence. The transporter showed significant sequence similarities to the yeast arginine and histidine transporters. A 2.0-kilobase RNA species was identified as the CTR transcript. Disruption of the CTR locus completely abolished the choline transport activity, indicating that the CTR product is the sole choline transporter in yeast. The regulation of choline transport mRNA was investigated by Northern blot analysis using a CTR probe. The abundance of CTR mRNA significantly decreased on incubation of cells with a combination of choline and myo-inositol. The CTR mRNA level was high in the exponential growth phase but decreased dramatically when cells entered the stationary phase. Similar control had been observed for some enzymes in yeast phospholipid synthesis.

Amino Acid Sequence↗
PubMed1990

A newly designed deodorant pad for urinary incontinence.

The authors designed a new pad for urinary incontinence. It is composed of a cloth of acrylonitrile copper sulfide and another cloth of iron-phthalocyanine. In vitro experiments showed that acrylonitrile copper sulfide cloth inhibited the growth of most bacteria causing urinary tract infection, and that iron-phthalocyanine cloth effectively eliminated bad-smelling gases. The use of this pad relieved diaper-dermatitis and diminished offensive smells from feces and urine. This pad was well received by nurses and helpers taking care of incontinent elderly people.

Acrylonitrile↗
PubMed1990

Repression of choline kinase by inositol and choline in Saccharomyces cerevisiae.

The regulation of choline kinase (EC 2.7.1.32), the initial enzyme in the CDP-choline pathway, was examined in Saccharomyces cerevisiae. The addition of myo-inositol to a culture of wild-type cells resulted in a significant decrease in choline kinase activity. Additional supplementation of choline caused a further reduction in the activity. The coding frame of the choline kinase gene, CK1, was joined to the carboxyl terminus of lacZ and expressed in Escherichia coli as a fusion protein, which was then used to prepare an anti-choline kinase antibody. Upon Western (immuno-) and Northern (RNA) blot analyses using the antibody and a CK1 probe, respectively, the decrease in the enzyme activity was found to be correlated with decreases in the enzyme amount and mRNA abundance. The molecular mass of the enzyme was estimated to be 66 kilodaltons, in agreement with the value predicted previously from the nucleotide sequence of the gene. The coding region of CK1 was replaced with that of lacZ, and CK1 expression was measured by assaying beta-galactosidase. The expression of beta-galactosidase from this fusion was repressed by myo-inositol and choline and derepressed in a time-dependent manner upon their removal. The present findings indicate that yeast choline kinase is regulated by myo-inositol and choline at the level of mRNA abundance.

Antibodies↗
PubMed1990

Antiproliferative activity of mammalian lignan derivatives against the human breast carcinoma cell line, ZR-75-1.

The effect of each of twelve mammalian lignan derivatives on the growth of human mammary tumor ZR-75-1 cells was examined. At a concentration less than 10 micrograms/ml, tumor cell growth was inhibited from 18-68%. The effect of 2,3-dibenzylbutane-1,4-diol(hattalin) was found to be strongest, inhibiting growth by 50% at a concentration (EC50) of 2.1 micrograms/ml. Hattalin inhibited membrane Na+, K(+)-ATPase of canine kidney cortex. It also inhibited the ATPase of the plasma membrane fraction from both cultured cells and a section of human breast cancer tissue at a concentration ranging from 0.5 to 2.0 mM. However, only a few percent of membrane ATPase from either ZR-75-1 cells or breast carcinoma tissue was inhibited by 2.0 mM of ouabain, suggesting that the target ATPase of hattalin was other than ouabain-sensitive ATPase. The relative incorporation of [3H]thymidine per 1 x 10(5) cells into the acid-precipitable fraction of ZR-75-1 cells was not affected by 1-50 micrograms/ml of hattalin, while a marked decrease resulted from 1-10 micrograms/ml of 5-fluorouracil (5-FU). These results suggest that the suppressive effect of hattalin on tumor cell growth may not occur through inhibition of DNA synthesis but rather partly by inhibition of the plasma membrane ATPase other than Na+ and K(+)-dependent ones.

4-Butyrolactone↗
PubMed1990

[Results of the conservative treatment of urinary incontinence in women].

We reviewed 115 incontinent women undergoing conservative treatment. Urinary incontinence was caused by pelvic floor weakness (genuine stress incontinence) in 54 patients, by involuntary detrusor contraction (detrusor instability) in 38 and by both (mixed type) in 23. Tricyclic antidepressants or alpha-adrenergic stimulators were given to 30 patients with pelvic floor weakness; Incontinence disappeared in 4 patients (13%) and was improved in other 3 patients (10%). Twenty-two patients with pelvic floor weakness underwent pelvic floor exercise with or without medication; Incontinence disappeared in 8 patients (36%) and was improved in other 11 patients (50%). The presence or absence of medication did not affect the results. Twenty-eight patients with involuntary detrusor contraction underwent bladder training combined with medication of detrusor relaxants. Incontinence disappeared in 4 patients (14%) and was improved in other 13 patients (46%); There was no significant difference in the results between smooth muscle relaxants and tricyclic antidepressants. Of the 23 patients with mixed type, 11 underwent bladder training with medication; Incontinence disappeared in 2 patients (18%) and was improved in 3 patients (27%). The remaining 11 patients received medication, pelvic floor exercise or urethral dilatation, and only 2 patients were cured or improved of incontinence. Follow-up of the patients with involuntary detrusor contraction or mixed type showed that urinary incontinence tended to recur after discontinuation of medication. These results indicate that incontinent women with pelvic floor weakness should be treated first with pelvic floor exercise, and then with bladder training with medication. Although it has only a limited effect, it is an acceptable treatment of urinary incontinence caused by involuntary detrusor contraction.

Adrenergic alpha-Agonists↗
PubMed1990

[Oral findings in severely handicapped patients participating in the periodic dental check-up system for five years--dental caries, gingival recessions and hyperplasias, periodontal diseases].

In March 1987, we investigated the quality of oral hygiene, and the incidence of dental caries and periodontal diseases in 140 severely handicapped patients who had been hospitalized in two national sanatorium. All of the patients had participated under the Matsumoto Dental College Hospital Periodic Dental Check-up System for five years. The results were as follows: 1. The teeth of all the subjects had been brushed by the sanatorium nursing staff twice per day. The prevailing brushing technique was the horizontal method. 2. 37.5% of the subjects showed complete adaptability to the tooth brushing by the nursing staff. However, 2.1% showed no adaptability whatsoever. 3. The mean value of the OHI-S was 1.53. The labial surfaces of the maxillary anterior teeth showed the lowest OHI-S value, while the mandibular left posterior teeth showed the highest. 4. The DMF-T was estimated to be 12.51 (DMFT ratio = 48.2%). The average D-T was 2.07 +/- 4.03, and the average F-T was 8.43 +/- 7.22. 5. 19.3% of the patients were diagnosed with gingival hyperplasia, and 10.7% had local gingival recessions. 1) Of the patients who had taken Phenytoin daily, 35.5% were diagnosed with hyperplasia. 2) Most local gingival recessions were found on the labial gingiva of the mandibular anterior teeth. A relationship was determined to exist the local recession and the horizontal brushing method. 6. 89.2% of the patients suffered from periodontal diseases.(ABSTRACT TRUNCATED AT 250 WORDS)

DMF Index↗
PubMed1990

[Relationships between development and adaptability to recumbent position brushing in preschool children].

This study was carried out to clearly establish a relationship between development and adaptability to recumbent position brushing in preschool children. We investigated the behavior of 98 normal children, under 6 years of age, while being brushed by their mothers who laid the children on their backs. Their developmental ages were estimated by Enjoji's Infant Analytic Development Test. The results were as follows: 1. 89.8% of the subjects' mothers brushed their children's teeth more than once per day. 2. The rate of the subjects observed displaying unsuitable behavior by interfering in the brushing with their hands was 20.4%. The rate of subjects who interfered by moving their bodies or heads was 17.3%, by closing their mouths, 15.3%, and by biting the toothbrush or crying was 13.3%. 3. 78.6% of the children readily adapted to recumbent position brushing, while 21.4% of the children were found to be unsuitable for the method. 4. 12.2% of the mothers held their children down while brushing their teeth. However, even with the occurrence of unsuitable behavior, 9.2% of the mothers did not restrain their children. 5. A significant relationship was observed between adaptability to the recumbent position brushing method and the developmental age of the subjects. 6. The developmental age (determined by Enjoi's Infant Analytic Developmental Test) at which the children were able to adapt to the method was about 2 years and 6 months. 7. It became clear to us that children over 2 years and 6 months developmental age will readily adapt to the recumbent position brushing method.

Child, Preschool↗
PubMed1989

Interconversion of polyamines in wild-type strains and mutants of yeasts and the effects of polyamines on their growth.

Yeasts of wild-type strains, such as Saccharomyces cerevisiae, Schizosaccharomyces pombe and Candida albicans were shown to have the ability to form aminopropylcadaverine and aminopropylhomospermidine from cadaverine and homospermidine, respectively. A polyamine autotroph S. cerevisiae 179-5, which lacks ornithine decarboxylase, produced both aminopropylcadaverine and aminopropylhomospermidine, while another mutant S. cerevisiae Y 260 A, which lacks spermine synthase, formed only aminopropylcadaverine. Naturally-occurring triamines and tetraamines except norspermidine and norspermine stimulated the growth of S. cerevisiae 179-5. All the six aliphatic diamines with carbon chain length ranging from one to six were effective in activating the growth of S. cerevisiae 179-5, though all of them were not converted to either triamines or tetraamines.

Candida albicans↗
PubMed1989

Interrelationship between Ca2+-dependent phospholipid base-exchange reaction and phospholipase D-like activity in bovine retina.

Endogenous substrates (phosphatidylserine, phosphatidylethanolamine and phosphatidylcholine) for the Ca2+-dependent base-exchange reaction were investigated using bovine retinal microsomes. The amounts of the three bases, serine, ethanolamine and choline, released from the membranes and the amount of phosphatidic acid generated in the membranes were measured in the presence of Ca2+ with or without exogenous bases. When the membranes were incubated with Ca2+ alone, the three bases were liberated into the water-soluble fractions accompanied by accumulation of phosphatidic acid, suggesting the presence of Ca2+-dependent phospholipase D-like activity. When an exogenous base was added to the reaction mixture, the liberation of the other two bases increased slightly and the formation of phosphatidic acid decreased markedly. The exogenous base also stimulated the liberation of the same base from prelabeled phospholipids. Accompanying these changes, the exogenous base was incorporated into the membrane phospholipid. With respect to pH profile, time course and metal requirements, both the base incorporation and phospholipase D-like activity were quite similar. The amount of base incorporated generally agreed with both the decreased amount of phosphatidic acid formed and the increased amount of base released. These results suggest that, beside the base-exchange reaction, phospholipase D-like activity plays an important role in Ca2+-dependent base incorporation into bovine retinal membranes.

Animals↗
PubMed1989

Biosynthesis of lipopolysaccharide in Escherichia coli. Cytoplasmic enzymes that attach 3-deoxy-D-manno-octulosonic acid to lipid A.

Previous studies in our laboratory led to the elucidation of the covalent structure of a tetraacyldisaccharide 1,4'-bisphosphate precursor of lipid A (designated lipid IVA), that accumulates at 42 degrees C in temperature-sensitive mutants defective in 3-deoxy-D-manno-octulosonic acid (KDO) biosynthesis (Raetz, C. R. H., Purcell, S., Meyer, M. V., Qureshi, N., and Takayama, K. (1985) J. Biol. Chem. 260, 16080-16088). Using [4'-32P]lipid IVA as the probe, we now demonstrate the existence of cytoplasmic KDO-transferases in Escherichia coli capable of attaching 2 KDO residues, derived from CMP-KDO, to lipid IVA. A partial purification has been developed to obtain a cytoplasmic subfraction that adds these 2 KDO residues with a 90% yield. The product is shown to have the stoichiometry of (KDO)2-IVA by fast atom bombardment mass spectrometry and NMR spectroscopy. The partially purified enzyme can utilize alternative lipid-disaccharide cosubstrates bearing five or six fatty acyl chains, but it has an absolute requirement for a monophosphate residue at position 4' of the lipid acceptor. When reincubated with a crude cytoplasmic fraction, a nucleoside triphosphate and Mg2+, (KDO)2-IVA is rapidly metabolized to more polar substances, the identity of which is unknown. The KDO-transferase(s) described in the present study should be very useful for the semisynthetic preparation of complex lipopolysaccharide substructures and analogs.

Cytidine Triphosphate↗
PubMed1989

Cloning and characterization of the yeast CKI gene encoding choline kinase and its expression in Escherichia coli.

Using a mutant defective in choline kinase (Hosaka, K., and Yamashita, S. (1980) J. Bacteriol. 143, 176-181; Hosaka, K., and Yamashita, S. (1987) Eur. J. Biochem. 162, 7-13), the structural gene (CKI) for choline kinase of the yeast, Saccharomyces cerevisiae, was isolated by means of genetic complementation. Within its sequence there was an open reading frame capable of encoding 582 amino acids with a calculated molecular weight of 66,316. The primary translation product contained a segment closely related to the phosphotransferase consensus sequence (Brenner, S. (1987) Nature 329, 21). A yeast transformant carrying CKI in multiple copies exhibited very high choline kinase activity as well as ethanolamine kinase activity. In-frame insertion of the CKI coding frame into lacZ' on the pUC19 vector led to efficient expression of choline kinase in Escherichia coli cells in the presence of a lac inducer, isopropylthiogalactoside, proving that CKI is the structural gene for choline kinase. Concomitantly, ethanolamine kinase activity was also expressed. When the CKI locus in the wild-type yeast genome was inactivated by its replacement with the in vitro disrupted cki gene, the yeast cells lost virtually all of the choline kinase activity and most of the ethanolamine kinase activity. Thus, it is concluded that choline kinase is mono-cistronic and that the ethanolamine kinase activity is a second activity of choline kinase in the yeast.

Amino Acid Sequence↗