c-axis microwave conductivity of YBa2Cu3O7- delta in the superconducting state.
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Biomedical subjects
Publications and source records attributed to H Kitano.
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For sequencing, mitochondrial DNA from Hansenula wingei yeast was digested with various restriction enzymes and the resultant DNA fragments were cloned into a pEMBL phasmid vector. Our clone bank consists of 39 overlapping clones which cover the entire 27,694 bp region of the H. wingei mitochondrial genome.
The complete 27,694-bp mitochondrial (mt) DNA sequence of Hansenula wingei, which is a typical budding yeast and contains circular mitochondrial DNA, has been determined. The mt sequence contains genes encoding large and small ribosomal RNAs, 25 tRNAs, three subunits of cytochrome c oxidase (subunits 1, 2 and 3), three subunits of ATPase (subunits 6, 8 and 9), apocytochrome b, seven subunits of NADH dehydrogenase (subunits 1, 2, 3, 4, 4L, 5 and 6), and a ribosomal protein, VAR1. The VAR1 gene is considered to be a typical yeast type. This is consistent with data on DNA and the deduced amino-acid sequence homology comparisons of genes ubiquitous in yeast and fungi. However, we have identified seven genes encoding NADH dehydrogenase subunits, which are not found in other yeast mitochondrial genomes, thus placing the H. wingei mitochondrial genome in a unique position. In addition the H. wingei mitochondrial genome also encodes one tRNA pseudogene and one short unidentified ORF. The genome is compact with only two introns both of which contain an ORF. One intron lies in the large rRNA gene while the other is situated in the cytochrome c oxidase subunit-1 gene. The conserved nonanucleotide motif (A/T)TATAAG (T/A)(A/T), which is a transcription start signal in Saccharomyces cerevisiae mitochondria, has also been found in the H. wingei mitochondrial genome. The codon assignments for ATA and CTN in H. wingei mitochondria are different from those in S. cerevisiae mitochondria. These results indicate a unique and novel structure for the H. wingei mitochondrial genome in terms of characteristics which are typical for both yeast and for filamentous fungi. This is the first complete mt DNA sequence report in yeast.
The two most common stimuli of the vestibular system for diagnostic purposes are caloric and rotational head movements. Caloric stimulation, by delivering thermal energy to the lateral semicircular canal, is a well-studied method of vestibular testing, and its clinical usefulness has been established. Vestibular autorotation testing uses high-frequency (2 to 6 Hz), active head movements to stimulate the horizontal and vertical vestibulo-ocular reflex to produce measurable eye movements that can be used to calculate gain and phase. We compared the alternate bilateral bithermal caloric results with the vestibular autorotation test results obtained from 39 patients with peripheral vestibular disorders and from 10 patients with acoustic neuroma. In the peripheral disorder group, only 2 of 14 patients with equal caloric response (< 20% reduced vestibular response) had a normal vestibular autorotation test result. No patients with a reduced vestibular response greater than 21% had a normal vestibular autorotation test result. In the acoustic neuroma group, four patients had a normal reduced vestibular response, but all patients had an abnormal vestibular autorotation test result. We conclude that testing both the horizontal and vertical vestibulo-ocular reflexes in their physiologic frequency range with the vestibular autorotation test provides additional information that could be missed by conventional caloric testing. Therefore high-frequency rotational testing is a valuable addition to the vestibular test battery.
An additional administration of high dose ethanol to chronic alcohol-fed rats led to a decrease in endotoxin clearance and an increase in endotoxin accumulation in the spleen accompanied by an elevation of tumour necrosis factor (TNF) levels in the portal vein. Endotoxin uptake and TNF production by Kupffer cells (KC) and splenic macrophages in the chronic ethanol load rats were significantly greater than those in the control rats. When these cells were precultured in the medium containing 10 to 100 mmol/L ethanol, the endotoxin uptake and TNF production of KC were decreased. However, this did not affect the endotoxin uptake and TNF production of splenic macrophages. The hepatic production of endotoxin binding protein was increased when KC were preincubated in the medium containing ethanol and the resultant culture supernatant was added to the hepatocyte culture system. This endotoxin binding protein was proved to enhance the uptake of endotoxin and suppressed the production of TNF in the KC. When KC and hepatocytes were isolated from chronically alcohol-fed rats, further addition of ethanol to the culture medium of KC did not affect the hepatic production of endotoxin binding protein. The increase in hepatic production of endotoxin binding protein may serve as a defence mechanism against endotoxicity. There is a possibility that an impairment of this defence mechanism has a pivotal role in the development of endotoxaemia and endotoxicity in chronic alcoholics.
The endotoxin inactivating action of plasma was evaluated in 62 patients with cirrhosis and 10 healthy subjects. Endotoxin from E. coli 0111:B4 was added to each plasma sample to a final concentration of 250 pg/ml and the percentage loss of endotoxin activity by incubation (37 degrees C for 1 h) was calculated as the endotoxin inactivating rate. The plasma endotoxin inactivating rate in cirrhotics was significantly greater than that in healthy subjects, although patients with Child C cirrhosis and marked hyperbilirubinemia had a significantly lower endotoxin inactivating rate than other cirrhotics. The plasma endotoxin inactivating rate was positively correlated to serum HDL-cholesterol levels. In patients with Child A and Child B cirrhosis, the endotoxin inactivating rate was positively correlated to the endotoxin binding capacity of plasma albumin. The present results support the assumption that the plasma of cirrhotics has a high endotoxin inactivating capacity. Its decrease may augment endotoxicity in patients with advanced liver cirrhosis.
Modification of an enzyme, alpha-chymotrypsin, was examined by using a water-soluble photo-Fenton reagent. By photoirradiation of the enzyme with the reagent, which can occupy a binding site of the enzyme, a tryptophan residue in the vicinity of the active site was oxidized to N-formylkynurenine. Concurrently, the catalytic properties of the enzyme were largely changed: the Km was increased and the kcat was decreased. The decrease in kcat for a specific amide substrate was the most significant among the esters and amides examined. The water-soluble photo-Fenton reagent would be useful to chemically modify relatively limited regions in biomolecules.
The cerebral metabolic rate of glucose (CMRglc) and cerebral blood flow (CBF) in rats were estimated noninvasively with a high-resolution animal positron emission tomography (PET) system that we recently developed. Qualifications of CMRglc and CBF were attempted with radiotracers, 18F-2-fluoro-2-deoxyglucose and 15O-water, respectively. From the data obtained with PET, the CMRglc and CBF values under pretreatment conditions were respectively calculated as 51 +/- 14 mumol/min/100 g and 61 +/- 7 ml/min/100 g under pentobarbital-anesthesia. These values were in close agreement with published data obtained with the autoradiographic technique. Moreover, an increase of 69% (mean) in CBF was detected after i.v. acetazolamide administration. The results indicate that this high-resolution animal PET scanner holds great potential for the assessment of drug-related metabolic and circulatory effects in intact and experimental animals.
Ambient pressure changes are known to induce vertigo and bodily disequilibrium, e.g. alternobaric vertigo. It is predicted, based on clinical observations of such vertigo, that the rates of pressure change are responsible for alternobaric vertigo. The aim of the present study was to clarify the influence of the rates of pressure change on the activities of primary vestibular neurons using an animal model of alternobaric vertigo. The responses of primary vestibular neurons to middle ear pressure stimuli were investigated in guinea pigs under 2 different rates of pressure change (+/- 50, +/- 100 mmH2O/sec). The following results were obtained. 1. The response rates and the gains of firing rates with pressure stimuli were larger under +/- 100 mmH2O/sec than under +/- 50 mmH2O/sec. 2. The onsets of responses to pressure stimuli were faster under +/- 100 mmH2O/sec than under +/- 50 mmH2O/sec. The results obtained in the present study reveal that vestibular activities are altered by the rates of ambient pressure change.
For long time, it has been believed that the yeast mitochondrial (mt) genome lacks NADH dehydrogenase subunit genes which are designated ND genes. However, our complete mtDNA sequencing of yeast Hansenula wingei led us to the first finding of seven mitochondrial ND genes. We investigated the distribution of ND genes in mtDNAs of other yeasts including Pichia membranaefaciens, Yarrowia lypolitica, Candida maltosa, Saccharomyces kluyveri and Saccharomyces exiguus. By Southern hybridization with probes of H. wingei's ND1, 2 and 5 genes, we detected positive signals on mtDNAs in P. membranaefaciens, Y. lypolitica, and C. maltosa. To confirm this, we cloned and sequenced DNA fragment of ND5 gene in P. membranaefaciens. We have discussed the sequence homology and genome structure.
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A 62-year-old Japanese male with a 40-year history of heavy smoking presented with a laryngeal verrucous carcinoma on his left vocal cord (T1a N0 M0). The lesion was treated with tegafur. Three weeks after the start of treatment the lesion had almost entirely disappeared, with only a small scar remaining. The vocal cords were stripped to remove the scar. Thirty months after tegafur treatment the patient shows no indications of recurrence or metastasis.
The responses of primary vestibular neurons and perilymphatic pressure changes to middle ear pressure stimuli in guinea pigs were investigated in order to clarify the direct effects of pressure stimulus on the vestibular apparatus. The vestibular response was related to the amount of middle ear pressure change applied at a rate of +/- 100 mmH2O/s. The neural response rates of vestibular units to positive pressure in the middle ear were significantly larger than those to negative pressure. The time course pattern of the perilymphatic pressure change resembled that of the response of the vestibular units, indicating that the vestibular response is elicited by middle ear pressure via the pressure transmitted in the inner ear.
The responses of primary vestibular neurons and perilymphatic pressure changes to middle ear pressure were investigated in guinea pigs with obstructed vestibular or cochlear aqueduct (closed VA or closed CA group) in order to clarify the influence of VA and CA on pressure-induced vestibular response. Although the neural response rates and the amount of perilymphatic pressure change in the closed VA group resembled those in the control group, these values in the closed CA group were higher than in the control group. Patency of the CA had a more significant effect on the vestibular response to middle ear pressure change than patency of the VA.
To study the effect of palm fruit carotene intake on skin lipid peroxidation, hairless mice were given ad libitum palm fruit carotene, beta-carotene, or vehicle emulsions for 15 weeks in which the carotene (0.005%, w/w) was suspended in drinking water, and then their dorsal skin was exposed to ultraviolet ray (UV). The carotene content of the skin was increased by the oral intake of palm fruit carotene or beta-carotene. In carotene-drinking mice, before the UV irradiation, the amount of thiobarbituric acid-reacting substances (TBARS) in the skin was lower than that of control (carotene untreated) mice. The skin TBARS immediately after the UV irradiation was lower in carotene-treated mice than in control mice. At 24 h after irradiation, the skin TBARS of mice that orally received palm fruit carotene was lower than that of beta-carotene mice. Immediately after the UV irradiation, the skin carotene content transiently decreased but gradual recovery was observed at 48 h. In palm fruit carotene-treated mice, the rate of carotene recovery after UV irradiation was higher than in beta-carotene-treated mice. Retinol found in the skin had also decreased after UV irradiation, and recovered gradually in both carotene-drinking groups within 48 h. These results suggested that the carotene intake, especially palm fruit carotene, prevented skin lipid peroxidation in hairless mice.
To study the antioxidant effect of palm fruit carotene on skin lipid peroxidation, the guinea pigs were orally fed ad libitum palm fruit carotene, beta-carotene, or vehicle emulsions, in which carotene (0.05%, w/w) was suspended in drinking water. After treatment of carotene for 12 weeks, animals were exposed to ultraviolet ray (UV), and squalene monohydroperoxide (SqOOH)/squalene (Sq) ratios in the skin lipid were analyzed using the chemiluminescence-HPLC method. Carotene accumulation was found in the skin of guinea pigs that were orally administered palm fruit carotene or beta-carotene. After UV irradiation, especially immediately after, the rise in the SqOOH/Sq ratio was effectively suppressed in both carotene-drinking groups in contrast with the control (carotene-untreated) group. An inverse correlation between the carotene content and the SqOOH/Sq ratio in the skin was also observed. The results suggested that palm fruit carotene intake prevents skin lipid peroxidation caused by UV irradiation.
We attempted to instruct the outpatients with malignant liver tumor (metastatic liver cancer and advanced hepatocellular carcinoma) who received intermittent arterial infusion chemotherapy using implanted reservoir to detach the devices for arterial infusion by themselves at home. All patients who received our instruction could master self-detachment at home, which shortened the hospitalized day. And patients' desire for this treatment promoted with improvement of the recognition of their families to participate in treatment together. We experienced no trouble which disturb the treatment. This methods was considered to promote the improvement of QOL of these patients.