Biomedical subjects

H Kamiya

Publications and source records attributed to H Kamiya.

At least 361 records · Page 20Linked to original sources

PubMed1989

Increased sensitivity to 1-beta-D-arabinofuranosylcytosine in P388 murine leukemic cells resistant to etoposide.

A variant P388 murine leukemic cell resistant to 4'-demethylepipodophyllotoxin-9-(4,6-O-ethylidine)-beta-D-gl ucopyranoside (etoposide) (VP-16-213) was cloned. The variant P388/VP-16 cell line was 159-fold resistant to VP-16. We found that this variant P388/VP-16 cell line showed collateral drug sensitivity to 1-beta-D-arabinofuranosylcytosine(Ara-C), determined by comparing the 50% inhibitory concentrations in 48-h growth inhibition assay. To clarify the mechanism of this increased sensitivity to Ara-C, we quantified the deoxyribonucleoside triphosphate pools and 1-beta-D-arabinofuranosylcytosine triphosphate(Ara-CTP) using high-performance liquid chromatography in the parent and drug-resistant sublines of P388 cells. The analysis of deoxyribonucleoside triphosphate pools revealed that the pyrimidine triphosphate pools were significantly decreased in the P388/VP-16 cell line and the Ara-CTP concentration of two variant cell lines were not significantly different. The Ara-CTP/dCTP ratio was significantly increased in P388/VP-16 cells. These data suggest that the inhibition of the dCTP de-novo pathway and the preservation of the dCTP salvage pathway in P388/VP-16 cells might correlate with the increased sensitivity to Ara-C.

Animals↗

PubMed1989

Purification of dolabellanin-C an antineoplastic glycoprotein in the body fluid of a sea hare, Dolabella auricularia.

An antineoplastic factor, dolabellanin C, inducing tumor lysis was purified to apparent homogeneity from the body fluid of the sea hare Dollabella auricularia. Purified dolabellanin C is a glyco-protein of 215 K daltons containing 3 subunits of 70 K daltons. The amino acid sequence of the amino terminal region was also determined. This factor was active even at 0.38 ng protein/ml, but did not lyse normal white or red blood cells.

Amino Acid Sequence↗

PubMed1989

Transformation of NIH3T3 cells with synthetic c-Ha-ras genes.

Synthetic human c-Ha-ras genes in which amino acid codons were altered to those which are frequently used in highly expressed Escherichia coli genes were ligated to the 3'-end of Rous sarcoma virus long terminal repeat. When NIH3T3 cells were transfected with the plasmids having those genes with valine at codon 12, leucine at codon 61 or arginine at codon 61, transformants were efficiently produced. These results indicated that the synthetic c-Ha-ras genes are expressed in a mammalian system even though their codon usage is altered to correspond with that of E. coli. This expression vector system should be useful for studies on the structure-function relationships of c-Ha-ras, since the synthetic gene can be easily modified to have multiple base alterations, and can also be used simultaneously for the production of large amounts of p21 in E. coli for biochemical and biophysical studies.

Avian Sarcoma Viruses↗

PubMed1989

Serum anti-PT and anti-FHA antibody levels, and agglutinin titers after administration of acellular pertussis vaccines.

Simultaneous evaluation of acellular pertussis vaccines from three manufacturers (Takeda, Biken, and Chiba) was performed. After receiving two doses of acellular pertussis vaccine in the form of DPT (diphtheria pertussis tetanus), both infants and children showed high serum anti-PT (pertussis toxin) and anti-FHA (filamentous hemagglutinin) antibody levels. These levels were equivalent to those observed in children in the convalescent stage of natural pertussis infection. Children who received 2 doses of Biken vaccine showed higher anti-PT and anti-FHA antibody levels than those who received Takeda or Chiba vaccine. Elevation of agglutinin titers was observed in children who received either Takeda or Chiba vaccine.

Antibodies, Bacterial↗

PubMed1989

Natural killing of varicella-zoster virus (VZV)-infected fibroblasts in normal children, children with VZV infections, and children with Hodgkin's disease.

We studied mononuclear cell (MNC)-mediated natural killing (NK) of varicella-zoster virus (VZV)-infected fibroblasts in normal children, children with VZV infections, and children with Hodgkin's disease. NK activity was tested in 18 hr 51Cr release assays. NK activity for adults was significantly higher than that for children 1-3 years old or 4-6 years old (p less than 0.05). Serological status did not affect NK activity. NK activity in normal children was not increased 4-6 weeks after immunization with varicella vaccine. Seven normal children with natural varicella showed significantly higher NK activity against VZV-infected and uninfected targets. Eight immunosuppressed children with herpes zoster showed significantly reduced NK activity within 72 hours of the onset of herpes zoster. However, their NK activity rose to the normal level one to two weeks later. Children with Hodgkin's disease had low NK activity. These results suggested that NK cells might play an initial defensive role in VZV infections, and that low NK activity in immunocompromised hosts might contribute to their high incidence of herpes zoster.

Adolescent↗

PubMed1989

Insulin secretion in childhood obesity.

In 132 severely obese children (72 boys and 60 girls) who underwent institutional therapy, oral glucose tolerance tests were carried out on admission, and these children were divided into groups with normal and high insulin levels, in terms of the sigma IRI values obtained, on the basis of the reference value + 2SD calculated by Maruhama et al. From these children, those who had diabetes mellitus (DM) and those in whom DM was suspected were distinguished according to the diagnostic criteria of USPHS (Drash et al). The insulin levels were normal in 58 children and high in 64. Ten children were found to have DM, and 19 were suspected to have DM. Metabolism of the glucose load occurred at both normal and high insulin levels in some children. There was also a group of children in whom glucose metabolism was incomplete at high insulin levels and a group of children in whom glucose metabolism was not possible even at high insulin levels, showing an obvious DM reaction. These findings suggest that there is a difference in the sensitivity of the insulin receptors in these children. Age, severe obesity and a family history of DM were considered to be risk factors for DM. Although there was a moderate, positive correlation between sigma IRI and the obesity index and between sigma IRI and age, it seems that the level of insulin secretion varies considerably in obese children.

Adolescent↗

PubMed1989

Purification and characterization of a cytolytic protein from purple fluid of the sea hare, Dolabella auricularia.

A novel cytolytic factor, dolabellanin P, was purified to apparent homogeneity from the purple fluid of the sea hare, Dolabella auricularia. Purified dolabellanin P is a single polypeptide of 60 kDa. The amino acid composition and the N-terminus of the factor were also determined. This factor nonspecifically lysed all the cells tested at 50-200 ng protein/ml. Dolabellanin P caused complete cytolysis within 2 h. The factor is distinct from antineoplastic glycoproteins previously isolated from eggs (aplysianin E) or albumen gland (aplysianin A) of Aplysia kurodai in terms of certain cytolytic properties. These results suggest that dolabellanin P, found in the sea hare, a marine invertebrate, is a new cytolytic factor.

Amino Acid Sequence↗

PubMed1989

Studies on sialic acids. XIII. Isolation of 3-deoxy-D-glycero-D-galacto-2-nonulopyranosonic acid (KDN) from chum salmon, Oncorhynchus keta.

A method for analysis of 3-deoxy-D-glycero-D-galacto-2-nonulopyranosonic acid (KDN) by high-performance liquid chromatography (HPLC) with a strongly basic anion-exchange resin was developed. The method was applied to detect free KDN in water used to rinse of fertilized eggs of chum salmon, Oncorhynchus keta. Furthermore, KDN was isolated from the water as a fully protected derivative.

Animals↗

PubMed1989

Biopolymers from marine invertebrates. X. Mode of action of an antibacterial glycoprotein, aplysianin E, from eggs of a sea hare, Aplysia kurodai.

An antibacterial factor, aplysianin E, was purified from the eggs of a sea hare, Aplysia kurodai. Purified aplysianin E was a glycoprotein of 250 kilo daltons consisting of 3 subunits, and showed both antibacterial and antineoplastic activities. The two activities were lost in parallel on heating and at low and high pH. This factor was half-maximally active for gram-positive and -negative bacteria at 0.12-3.3 micrograms/ml and its action was not bactericidal but bacteriostatic. Aplysianin E did not induce morphological elongation of bacteria or their release of adenosine triphosphate (ATP), but it completely inhibited the syntheses of deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) by E. coli within 10 min. These results suggest that aplysianin E, found in an invertebrate, the sea hare, is a new antibacterial protein and that it exerts its action by inhibiting nucleic acid synthesis, as a DNA-inhibiting chemotherapeutic drug does.

Animals↗

PubMed1989

Biopolymers from marine invertebrates. XI. Characterization of an antineoplastic glycoprotein, dolabellanin A, from the albumen gland of a sea hare, Dolabella auricularia.

An anti-neoplastic factor, dolabellanin A, inducing tumor lysis was purified from the albumen gland of a sea hare, Dolabella auricularia. Purified dolabellanin A was found to be a glycoprotein of 250 kilodaltons containing 4 subunits. This factor was half-maximally active towards a variety of tumor cells at 1-18 ng protein/ml and lysed tumor necrosis factor (TNF)-resistant tumor cells. Dolabellanin A was labile on heating, at low and high pH, and on treatment with urea, guanidine, sodium lauryl sulfate or trypsin, but not with 2-mercaptoethanol or periodate. Dolabellanin A completely inhibited the syntheses of deoxyribonucleic acid and ribonucleic acid by tumor cells within 1 h and caused their complete cytolysis within 18 h. Tumor lysis by dolabellanin A was not inhibited by anti-TNF antibody but was inhibited by certain sugars, suggesting that recognition of a sugar moiety is a key step in its induction of cytolysis. Dolabellanin A also prolonged the survival of mice bearing syngeneic MM46 ascitic tumors (p less than 0.001). These results suggest that dolabellanin A, found in an invertebrate, the sea hare, is a new antitumor factor.

Amino Acids↗

PubMed1989

Comparison of CCK-8 receptors in the pancreas and brain of rats using CCK-8 analogues.

The characteristics of cholecystokinin (CCK) receptors in rat pancreatic acini and in various regions of the brain were examined using synthetic CCK-8 or CCK-7 analogues. 3H-propionylated CCK-8 [( 3H]CCK-8) was used as a ligand. 1) The pancreatic CCK receptor had a single high affinity binding component with a dissociation constant, Kd, of 0.76 nM and a maximum number of specific binding sites, Bmax, of 271.91 fmol/mg protein. On the other hand, the CCK receptor in the cerebral cortex had a Kd of 1.66 nM and a Bmax of 30.15 fmol/mg protein. 2) The order of the potencies of CCK-7 and CCK-8 analogues with a substitution at position 3 or 4 to displace [3H]CCK-8 specific binding to the pancreatic acini was as follows: CCK-8 greater than CCK-7 = SucCCK-7 greater than Suc[Sar3]CCK-7 greater than Suc[D-Trp3]CCK-7 greater than Suc[D-Ala3]CCK-7 greater than [D-Trp4]CCK-8 = [D-Ala4] CCK-8. This order of potencies of CCK analogues was greatly different from that in the cerebral cortex. 3) The carboxy-terminal tetra-peptide (CCK-4) and penta-peptide (CCK-5) had very weak potencies in displacing [3H]CCK-8 binding in the pancreatic acini, which were 20 to 30-fold less than their potencies in the cerebral cortex. These results suggest that the recognition sites for CCK analogues in the pancreatic and brain CCK receptors are different.

Animals↗

PubMed1989

Two outbreaks of Yersinia pseudotuberculosis 5a infection in Japan.

In the summer of 1984 there occurred 2 outbreaks of infection with Yersinia pseudotuberculosis 5a. 58 persons ate meat products, vegetables and rice at a Japanese barbecue restaurant. 39/58 (67%) developed symptoms. In 19/39 persons an infection with Y. pseudotuberculosis could be diagnosed by stool cultures and/or serological techniques. Fever occurred in all patients, exanthema in 68% and abdominal pain in 68%. Thus, human yersiniosis due to Y. pseudotuberculosis 5a could be a febrile disease with exanthema and gastrointestinal disturbances. A transient acute renal failure developed around the 10th day of illness in 4 children. The source and mode of spread of this infection could not be clarified.

Adolescent↗

PubMed1989

[Experience with clarithromycin in pediatric patients].

Clarithromycin (TE-031, A-56268), a newly synthesized macrolide antibiotic, was administered to children and its efficacy was examined. The clinical efficacy rate of TE-031 was 88.5% in 26 patients with pediatric infections. This rate was regarded as quite high. A side effect, transaminase elevation, was observed in 1 out of the 26 patients but it was subsided after a cessation of the antibiotic treatment. TE-031 was considered to be effective antibiotic for the infectious disease in the pediatric fields because of highly efficacy rate.

Adolescent↗

PubMed1989

[Experience of fluconazole in pediatric patients].

Fluconazole is a triazole agent and possesses a potent antifungal activity against fungi such as Candida, Cryptococcus and Aspergillus. Fluconazole is well absorbed following oral administration and shows bioavailability almost comparable to that attained in intravenous administration. The serum half-life is as long as about 30 hours and distributed widely into organs and tissues. Because of these it is expected to exhibit good clinical efficacy in the deep-seated mycosis. We evaluated the efficacy of fluconazole given orally to 3 pediatric patients with deep mycosis and also with aim of evaluating its prophylactic effect, gave fluconazole to 4 patients who had high risks of mycotic infections. Pathogenic fungi isolated from the 3 patients with mycosis were all Candida albicans and diagnoses made were Candida pneumonia, oral candidiasis and gastrointestinal candidiasis. Clinical efficacies were judged to be good in all of the 3 patients and C. albicans were found eradicated following the treatment. In the 4 patients to whom fluconazole was given prophylactically, no mycosis developed. Fluconazole was well tolerated and no incidence of side effects or clinical laboratory parameter abnormalities were seen any of the patients involved in the study.

Administration, Oral↗

PubMed1989

Design of RNA enzymes for sequence-dependent cleavage of RNA.

We have designed synthetic ribozymes which can cleave specific sites of RNA. An undecamer, 5S rRNA and transcripts using T7 RNA polymerase were hydrolyzed at the X position of RNA containing (N)nUX(N)n (N = A, G, C and U; X = A, C and U) by these ribozymes.

Base Sequence↗

PubMed1989

[Pharmacokinetic and clinical studies on sulbactam/ampicillin in the pediatric field].

The new antibiotic, sulbactam/ampicillin (SBT/ABPC) was administered to 25 children. The results obtained are summarized as follows. 1. In 5 cases of children administered with SBT/ABPC (30 mg/kg) by intravenous drip infusion for 30 minutes, the mean values of T 1/2 (beta) were 0.94 hour (SBT) and 0.86 hour (ABPC) and the mean 6.5 hour urinary excretion rates were 64.2% and 42.9%, respectively. 2. The antibiotic was administered to a total of 25 patients with bronchopneumonia, pneumonia, bronchitis, cervical lymphadenitis, tonsillitis, streptococcal infection, urinary tract infection, felon, periappendicular abscess, sepsis or purulent meningitis. Response to the treatment were excellent in 17 cases, good in 7, fair in 1, and poor in none. The efficacy rate was 96%. From our results, this drug appears to be particularly effective against bronchopneumonia, bronchitis and urinary tract infection. 3. Eruption occurred in 1 of 25 patients and elevation of eosinophil, GOT/GPT, platelet in 3 and descent of WBC in 1 were observed, but these were transient. These results showed that SBT/ABPC is a drug which can be safely used in the pediatric field as well as for adults.

Age Factors↗

PubMed1989

[Laboratory and clinical investigations of cefodizime in infectious diseases in childhood].

In this study, cefodizime (CDZM, THR-221) was administered to 34 children with infections and the efficacy was evaluated in 30 patients. The efficacy rate was 90.0% and CDZM was proved to be a highly effective antibiotic for infectious diseases in childhood. We also demonstrated that CDZM had strong antibacterial activities against both Gram-positive and Gram-negative bacteria. No severe toxicity related to intravenous injection of CDZM was observed in our 34 cases.

Age Factors↗

PubMed1988

Direct projections of non-pyramidal neurons of Ammon's horn to the supramammillary region in the cat.

Non-pyramidal neurons in cat Ammon's horn were shown to send their axons to the supramammillary regions (SMR), i.e. the supramammillary nucleus and its vicinities including the supramammillary nucleus and the lateral, posterior and dorsal hypothalamic areas: wheat germ agglutinin-horseradish peroxidase (WGA-HRP) injection into Ammon's horn resulted in labeling of presumed axon terminals in the SMR; and after injecting HRP into the SMR, retrogradely labeled non-pyramidal neurons were seen in Ammon's horn.

Animals↗