PubMed Health⌕ Search

Biomedical subjects

K Urata

Publications and source records attributed to K Urata.

At least 55 records · Page 3Linked to original sources
PubMed1993

The mutation of codon 249 in the p53 gene is not specific in Japanese hepatocellular carcinoma.

Hepatocellular carcinoma samples obtained from 59 patients at surgical resection were examined for mutations of the third base at codon 249 of the p53 gene, using the polymerase chain reaction and oligonucleotide hybridization techniques. This point mutation, which is frequently observed in HCC cases from Southern Africa and Quidong in China, was not recognized in either 60 hepatocellular carcinomas or 53 noncancerous liver tissue samples from Japan. Thirty-four of 45 patients (75.6%) were positive for the hepatitis C virus, which was a higher rate than that for hepatitis B virus infection (9 of 55; 16.4%). The exposure to aflatoxin B1 was not considered to be remarkable. These results suggest that the point mutation of the third base at codon 249 is not common in Japanese patients, and it is suggested that numerous other factors affect the mutation of the p53 gene and the development of hepatocellular carcinoma.

Adult↗
PubMed1993

Efficacy of sulthiame (Ospolot) on motor partial seizure status during sleep in a patient with motor cortex epilepsy.

An 18-year-old female patient with a particular form of intractable motor cortex epilepsy, in which motor partial seizure status occurred only during sleep every night, was reported focusing on the drastic efficacy of sulthiame on the seizure status. Moreover, the present study demonstrated that single photon emission computed tomography (SPECT) and pulse oximetry examinations, both of which were performed in the ictal state, were useful for the regional diagnosis of the epileptic focus and observations of the seizure frequency, respectively. The therapeutic effect, epileptic picture and clinical examinations described here appear to be relatively rare in the literature, and therefore, this case report may be of clinical significance.

Adult↗
PubMed1993

[New membrane filter (PORETEC) method for ocular diagnostic cytopathology].

We describe a new membrane filter (PORETEC) technique for processing cytopathologic fluid specimens. This procedure provides excellent cytologic preparations because there is no background staining and only a small amount of fluid specimen is necessary, as there is little cell loss. We compared the number of cells collected by the membrane filter technique with that collected by cytocentrifugation using conjunctival brush cytology specimens from 6 subjects. The number of cells obtained by the new method was significantly higher than that obtained by the cytocentrifugation technique. This method was very useful for ocular fluid specimens such as aqueous humor, vitreous specimens, and scrapings from the cornea and conjunctiva. We showed some examples of these specimens including immunocytochemical staining done by this method. We confirm that this is valuable for diagnostic cytopathologic study of various fluid specimens in ophthalmology.

Adult↗
PubMed1992

Regional cerebral blood flow in patients with schizophrenia. A preliminary report.

Regional cerebral blood flow was evaluated using Tc99m-HMPAO SPECT in 10 medicated patients with schizophrenia and 9 healthy volunteers. There were no prefrontal regions in the patient group with lower regional indices than in the control group. However, in the left hippocampal region, relative blood flow was significantly increased in the patient group compared with the control group. Furthermore, there was a relative increase in blood flow in the left basal ganglia of the patient group. A negative correlation coefficient was calculated between the relative blood flow in the left middle prefrontal cortex and the severity of the blunted affect, as well as between the relative blood flow in the left basal ganglia and the severity of the anhedonia-asociality. These findings indicate that prefrontal hypoactivity is not invariably present in all schizophrenics and that left basal ganglial hyperactivity may be associated with the effects of antipsychotic treatment and clinical improvement. Moreover, the left hippocampal hyperactivity may correspond to left limbic dysfunction in schizophrenia.

Adult↗
PubMed1991

Respiration by tracheal insufflation of oxygen (TRIO) at high flow rates in apneic dogs.

Tracheal insufflation of oxygen (TRIO) is a technique in which oxygen is introduced into the trachea at a constant flow rate via a catheter advanced to the level of the carina. We studied the effects of flow rates (0.5, 1.0, 1.5 and 2.0 l.kg(-1).min(-1)) on arterial blood gases during TRIO in 6 apneic dogs. The constant flow was administered through the tip of a catheter (I.D. 2.0 mm) advanced to a site of 1 cm above the carina. After 30 min of TRIO, the mean Pa(CO)(2) at the flow rates of 0.5, 1.0, 1.5 and 2.0 l.kg(-1).min(-1) were 88 +/- 20, 76 +/- 20, 64 +/- 23 and 52 +/- 18 mmHg, respectively. CO(2) elimination increased as the flow rates increased from 0.5 to 2.0 l.kg(-1).min(-1). Based on the above study, we examined the effects of TRIO at a flow rate of 3 l.kg(-1).min(-1) in another 5 apneic dogs. TRIO, at a flow rate of 3 l.kg(-1).min(-1), was able to maintain normocarbia over 4 hr. The mean Pa(O)(2) and Pa(CO)(2) at 4.0 hr were 465 +/- 77 and 41 +/- 4 mmHg. Although the mechanism of pulmonary gas exchange during TRIO is unclear, our study is the first to document that normocarbia can be maintained by high-flow TRIO in apneic dots.

Journal Article↗
PubMed1989

Effects of tracheal insufflation of oxygen (TRIO) on blood gases during external cardiac compressions in dogs under ventricular fibrillation.

Tracheal insufflation of oxygen (TRIO) is a form of constant-flow ventilation. We studied the effect of TRIO at a flow rate of 2 L/kg/min on arterial blood gases during external cardiac compressions in dogs with ventricular fibrillation. During the combined application of TRIO and external cardiac compressions, all animals were adequately oxygenated and hyperventilated except in cases where lung edema developed in the course of cardiopulmonary resuscitation (CPR). No pulmonary barotrauma was observed. The findings suggest that TRIO might be used as a temporary measure for emergency ventilation when CPR is performed in certain situations such as upper airway abnormalities or cardiac arrest outside the hospital setting, where intermittent positive pressure ventilation is not feasible.

Journal Article↗
PubMed1988

Acute respiratory failure induced by mechanical pulmonary ventilation at a peak inspiratory pressure of 40 cmH2O.

The effects of high pressure mechanical pulmonary ventilation at a peak inspiratory pressure of 40 cmH(2)O were studied on the lungs of healthy newborn pigs (14-21 days after birth). Forty percent oxygen in nitrogen was used for ventilation to prevent oxygen intoxication. The control group (6 pigs) was ventilated for 48 hours at a peak inspiratory pressure less than 18 cmH(2)O and a PEEP of 3-5 cmH(2)O with a normal tidal volume, and a respiratory rate of 20 times/min. The control group showed few deleterious changes in the lungs for 48 hours. Eleven newborn pigs were ventilated at a peak inspiratory pressure of 40 cmH(2)O with a PEEP of 3-5 cmH(2)O and a respiratory rate of 20 times/min. To avoid respiratory alkalosis, a dead space was placed in the respiratory circuit, and normocarbia was maintained by adjusting dead space volume. In all cases in the latter group, severe pulmonary impairments, such as abnormal chest roentgenograms, hypoxemia, decreased total static lung compliance, high incidence of pneumothorax, congestive atelectasis, and increased lung weight were found within 48 hours of ventilation. When the pulmonary impairments became manifest, 6 of the 11 newborn pigs were switched to the conventional medical and ventilatory therapies for 3-6 days. However, all of them became ventilator dependent, and severe lung pathology was found at autopsy. These pulmonary insults by high pressure mechanical pulmonary ventilation could be occurring not infrequently in the respiratory management of patients with respiratory failure.

Journal Article↗
PubMed1984

Redox properties of membrane-bound b-type cytochromes and a soluble c-type cytochrome of nitrate reductase in a photodenitrifier, Rhodopseudomonas sphaeroides forma sp. denitrificans.

In order to identify the b-type cytochrome involved in the nitrate reduction in a photodenitrifier, Rhodopseudomonas sphaeroides forma sp. denitrificans, the b-type cytochromes in the spheroplast membranes were characterized. Difference spectra at 77K of spheroplast membranes indicated the presence of two b-type cytochromes with a bands at 556.5 and 562 nm. Three components considered to be of the b-type cytochrome were resolved by anaerobic potentiometric titration at 560-572 nm. Their midpoint potentials at pH 7, Em,7, were - 135 mV, +40 mV and +175 nm and their approximate reduced minus oxidized maxima were determined to be at 565 nm (562 nm at 77K), 560 nm (556.5 nm) and 560 nm (556.5 nm), respectively. These values are almost the same as those reported for R. sphaeroides. The Em,7 value of the cytochrome c involved in the nitrate reductase of this denitrifier was determined to be 250 mV. A b-type cytochrome reduced with NADH and FMN was oxidized by nitrate in chromatophore membranes. The possibility that cytochrome b (Em,7 = 175 mV) is involved in the nitrate reduction is discussed.

Cell Membrane↗