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Biomedical subjects

K Kita

Publications and source records attributed to K Kita.

At least 163 records · Page 9Linked to original sources
PubMed1997

Normal S cone electroretinogram b-wave in Oguchi's disease.

AIM: The short wavelength sensitive (S) cone electroretinograms (ERGs) were examined in two patients with Oguchi's disease to study S cone function. METHODS: Ganzfeld colour flashes under bright white background illumination were used to elicit S cone, and mixed long (L) and middle (M) wavelength sensitive cone ERGs. RESULTS: The S cone ERG b-wave was normal with short wavelength stimuli with normal L and M cone responses in both patients. CONCLUSIONS: These ERG results indicate that the S cone system as well as the L and M cone system is not defective in Oguchi's disease, while the S cone responses are not detectable in the complete type of congenital stationary night blindness as reported previously. The results imply that there is a significant difference in the way the S cone system is affected in different forms of stationary night blindness, and that the S cone and rod do not share the same arrestin system.

Adult↗
PubMed1997

Cytochrome b in human complex II (succinate-ubiquinone oxidoreductase): cDNA cloning of the components in liver mitochondria and chromosome assignment of the genes for the large (SDHC) and small (SDHD) subunits to 1q21 and 11q23.

Complex II (succinate-ubiquinone oxidoreductase) is an important enzyme complex in both the tricarboxylic acid cycle and the aerobic respiratory chains of mitochondria in eukaryotic cells and prokaryotic organisms. In this study, the amino acid sequences of the large (cybL) and small (cybS) subunits of cytochrome b in human liver complex II were deduced from cDNAs isolated by homology probing with mixed primers for the polymerase chain reaction. The mature cybL and cybS contain 140 and 103 amino acids, respectively, and show little similarity to the amino acid sequences of the subunits from other species in contrast to the highly conserved features of the flavoprotein (Fp) subunit and iron-sulfur protein (Ip) subunit. From hydrophobicity analysis, both cybL and cybS appear to have three transmembrane segments, indicating their role as membrane-anchors for the enzyme complex. Histidine residues, which are possible heme axial ligands in cytochrome b of complex II, were found in the second transmembrane segment of each subunit. The genes for cybL (SDHC) and cybS (SDHD) were mapped to chromosome 1q21 and 11q23, respectively by fluorescent in situ hybridization (FISH).

Base Sequence↗
PubMed1997

[The skin vasomotor dysfunction of the juvenile muscular atrophy of the distal upper limb--investigation by the ice water immersion test].

We investigated the skin vasomotor function of the juvenile muscular atrophy of the distal upper limb (JMA) by the ice water immersion test. The skin temperature of the bilateral second fingers during ice water immersion were measured in 17 patients with JMA and 25 normal controls. The insufficient fall of the skin temperature during ice water immersion was observed in 5 patients (3 patients in atrophic side, 2 patients in non-atrophic side). The insufficient recovery of the skin temperature was observed in 6 patients (3 patients in atrophic side, 3 patients in non-atrophic side). The both of the insufficient fall and recovery of the skin temperature was observed in one patient (both sides). The insufficient fall of the skin temperature indicates the hypofunction of skin vasomotor activity, and the insufficient recovery of the skin temperature indicates the hyperfunction of skin vasomotor activity because JMA has no disturbance of the peripheral sensory nerve fibers. We conclude that the responsible lesion of these abnormalities may be in the descending sympathetic tract in the cervical spinal cord.

Adolescent↗
PubMed1997

Clinical importance of interleukin-2 receptor alpha-chain expression in acute leukemia. The Japan Cooperative Group of Leukemia/Lymphoma.

To clarify the clinical importance of interleukin-2 (IL-2) receptor (IL-2R) expression in acute leukemia, we examined 517 adult patients with acute leukemia and CML blast crisis (CML-BC). IL-2R alpha was expressed in 42/311 AML, 5/11 acute unclassified leukemia, 24/116 pre-B ALL, 2/32 T-ALL, and 27/47 CML-BC, while IL-2R beta was expressed only in 2 T-ALL. Expression of IL-2R alpha was closely associated with that of different lineage markers, CD11b, CD34, and Ph1+ abnormality. IL-2R alpha(+) non-T leukemic cells did not respond to IL-2. Clinical outcome of IL-2R alpha (+) leukemia showed lower response to conventional chemotherapy and poorer prognosis than IL-2R alpha (-) cases. Serum IL-2R alpha level in IL-2R alpha (+) cases increased at the onset. Our findings indicate the diagnostic importance of IL-2R alpha expression in acute leukemia as a prognostic risk factor with a close relation to the particular cellular characteristics.

Acute Disease↗
PubMed1997

A study of the quality of life in elderly people using psychological testing.

To study factors which influence the quality of life (QOL) in the elderly, we investigated the relationship between scores on the modified Philadelphia Geriatric Center (JPGC) Morale Scale and various other psychological tests in 51 elderly people residing in a long-term care facility. The JPGC Morale Scale score correlated with the scores for all sections of the Japanese version of the Cornell Medical Index (JCMI), but not with those for the Mini Mental State Examination, the Kohs block design test, the Bender Gestalt test and the activities of daily living (ADL). Both somatic and psychotic symptoms on the JCMI were correlated with the dementia behaviour disturbance scale score and walking ability according to the ADL. Subjects were further divided into four groups according to Fukamachi's neurotic discriminative diagram based on the JCMI. Scores for most sections of somatic and psychotic symptoms on the JCMI were elevated in proportion to the degree of neurotic tendencies in the elderly. These results indicate that the QOL of the elderly is influenced by subjective symptoms, but not by the degree of cognitive impairment or the ADL.

Activities of Daily Living↗
PubMed1997

[Coronary artery bypass grafting in patients aged 80 years or older].

Coronary artery bypass grafting (CABG) in elderly patients was increasing in recent years. Between January 1989, and December 1996, 11 patients aged 80 years or older (mean 81) underwent CABG in our hospital. Nine patients (82%) were in New York Heart Association class III or IV. Emergency surgery was required in 4 patients (36%). Incidence of emergency surgery is higher than younger patients (p < 0.005), emergency surgery required 7.7% (46/592) in younger patients. The operative mortality was 27% for these 80 years or older. It was one in elective cases and two of four (50%) in emergency cases. One operative death in elective cases was concomitant operation with arch aneurysm. More patients of CABG operations in octogenarians required emergency surgery, and emergency surgery is high operative mortality. Thus CABG in octogenarians should be performed earlier, not be denied because of age alone.

Age Factors↗
PubMed1997

[Acute myelogenous leukemia (M4) occurring during chronic lymphocytic leukemia].

A 68 year-old-man was first found to have CLL with IgG, kappa monoclonal gammopathy 6 years ago. Bestrabucil (total dose 35,150 mg) was taken orally from August 1989 to December 1989. Etoposide (total dose 23,100 mg) was then orally administered from January 1990 to December 1995. He was then referred to our hospital in January 1996 because of progressive anemia and thrombocytopenia. Peripheral blood showed a WBC of 21,200/microliter with 4% myeloblasts and 79% lymphocytes, Hb 7.9 g/dl and Plt 5 x 10(4)/microliter. The serum level of lysozyme was increased (75.6 micrograms/ml). Bone marrow aspiration disclosed hyper-cellularity with proliferation of the blasts and a monocytoid cell population, which cytochemical studies demonstrated to be of the myelo-monocytic series, thus indicating acute myelogenous leukemia (AML-M4) superimposed on CLL. Surface marker analysis of bone marrow mononuclear cells revealed reactivity for CD 11c, CD13, CD15, CD33, HLA-DR. The karyotype was normal. Southern blot analysis and reverse transcriptase-polymerase chain reaction did not reveal rearrangement of the MLL gene. Complete remission was achieved by chemotherapy consisted of BHAC, idarubicine, 6MP, vincristine and predonisolone. Long-term treatment with oral etoposide may contribute to secondary AML.

Aged↗
PubMed1996

DnaK heat shock protein of Escherichia coli maintains the negative supercoiling of DNA against thermal stress.

Plasmid DNA in exponentially growing Escherichia coli immediately relaxes after heat shock, and the relaxed state of DNA rapidly reverts to the original state with exposure to conditions of heat shock. We have now obtained genetic and biochemical evidence indicating that DnaK heat shock protein of E. coli, a prokaryotic homologue of hsp70, is involved in this re-supercoiling of DNA. As re-supercoiling of DNA did not occur in an rpoH amber mutant, it seems likely that heat shock proteins are required for this reaction. Plasmid DNA in a dnaK deletion mutant relaxed excessively after temperature shift-up, and the re-supercoiling of DNA was not observed. DNAs incubated with a crude cell extract prepared from the dnaK mutant were more relaxed than seen with the extract from its isogenic wild-type strain, and the addition of purified DnaK protein to the mutant extract led to an increase in the negative supercoiling of DNA. Moreover, reaction products of purified DNA gyrase more negatively supercoiled in the presence of DnaK protein. Based on these results, we propose that DnaK protein plays a role in maintaining the negative supercoiling of DNA against thermal stress.

Cell Extracts↗
PubMed1996

An antibiotic, ascofuranone, specifically inhibits respiration and in vitro growth of long slender bloodstream forms of Trypanosoma brucei brucei.

Ascofuranone, a prenylphenol antibiotic isolated from a phytopathogenic fungus, Ascochyta visiae, strongly inhibited both glucose-dependent cellular respiration and glycerol-3-phosphate-dependent mitochondrial O2 consumption of long slender bloodstream forms of Trypanosoma brucei brucei. This inhibition was suggested to be due to inhibition of the mitochondriai electron-transport system, composed of glycerol-3-phosphate dehydrogenase (EC 1.1.99.5) and plant-like alternative oxidase. Ascofuranone noncompetitively inhibited the reduced coenzyme Q1-dependent O2 uptake of the mitochondria with respect to ubiquinol (Ki = 2.38 nM). Therefore, the susceptible site is deduced to be the ubiquinone redox machinery which links the two enzyme activities. Further, ascofuranone in combination with glycerol completely blocked energy production, and potently inhibited the in vitro growth of the parasite. Our findings suggest that ascofuranone might be a promising candidate for the chemotherapeutic agents of African trypanosomiasis.

Animals↗
PubMed1996

Cloning of a cDNA encoding the small subunit of cytochrome b558 (cybS) of mitochondrial fumarate reductase (complex II) from adult Ascaris suum.

Complex II in the mitochondria of the adult parasitic nematode, Ascaris suum, exhibits high fumarate reductase activity in addition to succinate dehydrogenase activity and plays a key role in the anaerobic energy metabolism of the worm. In this study, the amino acid sequence of the small subunit of cytochrome b558 (cybS) in adult complex II was deduced from the cDNA isolated by immunoscreening an A. suum muscle cDNA library. Histidine residues, which are possible heme axial ligands in cytochrome b558, were found in the second transmembrane segment of the subunit. This is the first report of the primary structure of the small subunit in the two-subunit cytochrome b in mitochondrial complex II from a multicellular eukaryote.

Amino Acid Sequence↗
PubMed1996

Treatment of primary erythromelalgia with cyproheptadine.

Erythromelalgia is a rare disorder characterized by burning pain of the extremities associated with red discoloration and increased temperature of the skin. We observed the effects of several drugs on two patients with primary erythromelalgia. Anti-inflammatory drugs such as aspirin had no effects for their symptoms. The alpha-adrenergic agonist midodrine slightly reduced skin temperature and redness of the extremities, and minimally reduced the pain in one patient. The partial alpha-adrenergic agonist and 5-hydroxytryptamine (5-HT) agonist/antagonist dihydroergotamine transiently reduced skin temperature and pain to some degree in one patient. The 5-HT and histamine antagonist cyproheptadine effectively relieved the burning pain and increased skin temperature.

Adult↗
PubMed1996

Promoter region of the rat phosphoribosylpyrophosphate synthetase-associated protein 39.

The 5' region of the 39-kDa rat phosphoribosylpyrophosphate synthetase-associated protein (PAP39) gene was isolated and sequenced. The promoter region of the rat PAP39 is GC-rich and contains potential binding sites for regulatory factors. Its promoter activity was demonstrated by transfection of the promoter region in fusion with the chloramphenicol acetyltransferase gene into rat pheochromocytoma PC12 cell.

Amino Acid Sequence↗
PubMed1996

Purification and molecular characterization of a novel b5-type cytochrome of the parasitic nematode, Ascaris suum.

A b5-type cytochrome was extracted from Ascaris suum muscle at pH 4.5 with 0.3% aluminum sulfate and purified by ammonium sulfate fractionation, ion-exchange chromatography on CM-500 Cellulofine, and gel filtration on Sephadex G-75. The hemoprotein displayed a typical absorption spectrum of cytochrome b with a midpoint redox potential of 78 mV. The N-terminal amino acid sequence was determined and revealed the N-terminus to be highly homologous to the heme-binding domain of vertebrate cytochrome b5. Using an oligonucleotide probe synthesized based on the amino acid sequence of the purified protein, the cDNA clone encoding A. suum cytochrome b5 was isolated from the lambda ZAP II cDNA library. The entire nucleotide sequence of 563 bases comprised an open reading frame of 339 bases encoding a precursor protein of 112 amino acid residues. The purified cytochrome B5 was predicted to contain 82 amino acids with a molecular mass of 9141 Da, matching the 9140 Da obtained from electrospray ionization mass spectometry, and to lack of membrane-anchor domain at the C-terminus. In contrast, an N-terminal extension of 30 amino acids, characteristic of signal peptides, was apparent. Immunoblots revealed the presence of an A. suum cytochrome b5 of 82 amino acids, but no protein with an N-terminal extension. These results demonstrate a novel cytochrome b5 possessing a presequence.

Amino Acid Sequence↗
PubMed1996

Crystallization and preliminary X-ray diffraction study of aldehyde reductase from a red yeast, Sporobolomyces salmonicolor.

Crystals of aldehyde reductase from a red yeast, Sporobolomyces salmonicolor, have been grown from an ammonium sulfate solution, pH 7.0, by means of the vapor-diffusion procedure. The crystals belong to the hexagonal system, space group P6(1)22 or its enantiomorph, P6(5)22, with unit-cell dimensions of a = 72.2 and c = 320 A. The X-ray diffraction patterns extend to at least 2 A resolution with the use of synchrotron radiation. The crystals are stable on exposure to X-rays and suitable for high-resolution X-ray structure determination.

Journal Article↗