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Biomedical subjects

M Uchida

Publications and source records attributed to M Uchida.

At least 253 records · Page 14Linked to original sources
PubMed1993

[Multiple primary cancers in patients with head and neck cancer and history of tobacco smoking and drinking].

In a total of 2083 cases of hollow organ cancer of the head and neck region treated in our institute in the past 20 years, the relative risk of second primary cancers was statistically studied by the person-year approach. The organ association in multiple primary cancers and the relationship between tobacco and alcohol consumption and the development of second primary cancers were also reviewed. The incidence of second primary cancers was significantly (p < 0.05) higher in patients having a lesion at the tongue (n = 502), mesopharynx (n = 188), hypopharynx (n = 224) and larynx (n = 621) and in the oral cavity (n = 203) than in the general population. With regard to organ association in multiple primary cancers, cancers in the oral cavity, esophagus and at the pharynx were found to occur as second primary cancers of the tongue, oral cavity, meso-hypopharynx and larynx at significantly high rates in males. Male laryngeal cancer was related to the lung. No relation of female lingual cancer to the esophagus was noted. The incidence of second primary cancer was very high in persons who had been heavy smokers and/or heavy drinkers before the occurrence of their primary cancer in the head and neck region. In these people, second primary cancers were found to occur at high rates as cancers related to tobacco smoking and drinking. Otherwise, in cases with head and neck cancers less related to tobacco smoking and drinking, the incidence of second primary cancers was low. From the above results, tobacco smoking and drinking may be closely related to a high incidence of second primary cancer following the first primary cancer in the head and neck region.

Aged↗
PubMed1993

[Effects of morphine, buprenorphine and butorphanol on airway dynamics of the rabbit].

An investigation was made on the effects of morphine, buprenorphine, and butorphanol on airway dynamics with special reference to the airway smooth muscle in rabbits. After tracheostomy under anesthesia, the animals were ventilated with a Servo 900B ventilator, and airway resistance (R) and total compliance (C) were measured according to the method of Norlander, and the effect of each drug was examined. Intravenous injection of morphine 0.2 mg.kg-1 increased R significantly at 10 and 20 minutes after its administration in nontreated animals and changed R insignificantly in animals pretreated with intravenous administration of chlorpheniramine 2.5 mg, an antihistaminic. It is considered that the increase in R after the administration of morphine in the nontreated animals is due to histamine release. Buprenorphine 0.8 micrograms.kg-1 and butorphanol 0.1 mg.kg-1 brought no significant changes in R in both nontreated and the chlorpheniramine pretreated animals. C decreased in all the groups including the control group which received mechanical ventilation alone without any drug administration.

Airway Resistance↗
PubMed1993

Effect of the novel histamine H2-antagonist 5,6-dimethyl-2-[4-[3-(1- piperidinomethyl)phenoxy]-(z)-2-butenylamino]-4(1H)-pyrimidine dihydrochloride on histamine-induced gastric acid secretion in Heidenhain pouch dogs.

Effects of IGN-2098 (5,6-dimethyl-2-[4-[3-(1-piperidinomethyl)phenoxy]- (z)-2-butenylamino]-4(1H)-pyrimidone dihydrochloride, CAS 126869-04-3) a novel histamine H2-antagonist, on histamine-induced gastric acid secretion were investigated in Heidenhain pouch dogs in comparison with those of famotidine, roxatidine acetate HCl and cimetidine. Orally administered IGN-2098 (0.03-1.0 mg/kg), famotidine (0.01-0.3 mg/kg), roxatidine acetate HCl (0.1-1.0 mg/kg) and cimetidine (0.3-3.0 mg/kg) showed dose-dependent inhibition on histamine-induced gastric acid secretion, and ED50 values of IGN-2098, famotidine, roxatidine acetate HCl and cimetidine were 0.077, 0.024, 0.200 and 0.585 mg/kg, respectively. IGN-2098 was effective even at 6 h after administration and ED50 value was 0.315 mg/kg. IGN-2098 was effective also by intravenous route. The inhibitory effect of IGN-2098 on histamine-induced gastric secretion was not affected by the repeated administration of IGN-2098 (1 mg/kg b.i.d. for 14 days). These results show that IGN-2098 is a potent and long acting antisecretory agent and is a useful antisecretory drug for the treatment of peptic ulcer disease.

Administration, Oral↗
PubMed1993

[A graphic presentation of the anesthesiologist's action pattern].

The action patterns of anesthesiologists are different among individuals. We have developed a graphic presentation system for anesthesiologists' action patterns using computer graphics. The resulting representation is called "thought map". Data were obtained from 6 anesthesiologists (4 certified instructors and 2 new doctors) with a time interval of 2 years, regarding the use of 3 drugs (enflurane, sevoflurane and isoflurane). The "maps" were compared among individuals, dates and drugs. The following results were obtained: 1) significant differences existed among individuals, 2) during the 2-year time interval, 2 new drugs were introduced and the practice pattern alterations were seen in the maps, 3) for the 2 new anesthesiologists, the maps show the process of professional knowledge acquisition. We propose an index ("immovable rate"), denoting the proportion of the map where concentration of the drug didn't change. This index is to be used for evaluating human thinking.

Anesthesia, Inhalation↗
PubMed1993

Action mechanism of idarubicin (4-demethoxydaunorubicin) as compared with daunorubicin in leukemic cells.

To characterize a new anthracycline agent, idarubicin (4-demethoxydaunorubicin) and to establish its reasonable and appropriate use in the chemotherapy of acute leukemia, we examined its mode of action and compared it with the results obtained for daunorubicin. Idarubicin was shown to have the characteristic features of the action mechanism of anthracyclines, such as having a strong binding capacity to DNA, in terms of frequency and efficiency and reducing the template activity of DNA by binding to DNA or inducing DNA strand breaks in leukemic cells and inhibiting the DNA polymerase reaction. Idarubicin was superior to daunorubicin in terms of intracellular accumulation and binding capacity to DNA, which may result in idarubicin having much stronger activity in inducing DNA strand breaks than daunorubicin. These excellent properties of idarubicin were considered to explain idarubicin having stronger antileukemic effects than daunorubicin. The efficacy of idarubicin in multidrug-resistant cells is also discussed.

Daunorubicin↗
PubMed1993

[Clinical experience of endopyelotomy].

From July 1986, percutaneous endopyelotomy was performed on a total of 12 patients (13 kidneys) including 8 males and 4 females with ureteropelvic junction (UPJ) obstruction. Of the 13 kidneys, 9 had primary UPJ obstruction and 4 had secondary UPJ obstruction. A rigid urethrotome (cold knife) was employed in 12 cases and a flexible electorotome (hot knife) in one case. A stent ureteral catheter was placed for 3 to 31 weeks after the procedure. The outcome was evaluated by radiography and urodynamic examinations. A successful outcome was obtained in 8 of 9 kidneys with primary UPJ obstruction and in 1 of 4 kidneys with secondary UPJ obstruction. These findings suggest that percutaneous endopyelotomy is useful in the treatment of primary UPJ obstruction.

Adolescent↗
PubMed1992

[MR imaging of thymoma--comparison with CT, operative, and pathological findings].

Twenty-six patients with thymoma, who had magnetic resonance (MR) imaging and computed tomography (CT) before surgery, were studied. Twenty-six thymomas were classified into 11 non-invasive thymomas (Masaoka's clinical stage I) and 15 invasive thymomas (stage II, III, and IV). On MR imaging compared with histological findings, low signal intensity rim of the tumor was corresponded to fibrous capsule of the tumor, and linear and/or reticular low signal intensity lines in the tumor were corresponded to the fibrous septae dividing thymoma into lobules. The detectability of these findings by MR imaging was superior to that by CT. Margin of the tumor was smooth in non-invasive thymoma rather than invasive thymoma. The diagnostic accuracy of invasion to vessel, and pleura or lung on MR imaging and CT was compared with operative and histological findings. MR imaging was same as CT in its ability to detect tumoral invasion to vessel, and slightly superior to pleura or lung. In conclusion MR images clearly show the findings corresponding to pathologic specimens, and MR imaging combining with CT is useful to differentiate non-invasive thymoma to invasive thymoma.

Adult↗
PubMed1992

On the mechanism of termination and perpetuation of atrial fibrillation.

In an effort to further clarify the mechanism of termination and perpetuation of atrial fibrillation (AF), the intraatrial potentials during AF induced by programmable electrical stimulation were analyzed using the concept of wavelength which represents the size of a microreentrant circuit. Thirty patients with inducible AF were divided into 2 groups: 20 patients with AF that terminated spontaneously (group 1) and 10 patients with AF that did not terminate spontaneously (group 2). Wavelength is the product of refractory period and conduction velocity. During AF, the refractory period of the local atrial tissue was considered to correlate with the mean interval between each intraatrial potential (mean ff). An inverse relation was considered present between conduction velocity of the impulse and the width of intraatrial potentials (f width). Thus, the wavelength index was defined as (mean ff)/(mean f width). Ten intraatrial potentials at the high right atrium were sampled for measurement. Group 1 had higher wavelength indexes just after the induction of AF than did group 2 (1.33 +/- 0.31 vs 1.10 +/- 0.05, p less than 0.05). In group 1, the wavelength indexes were increased from the initial value to 1.49 +/- 0.36 just before termination of AF (p less than 0.001). In 3 group 2 patients, AF stopped after disopyramide was administered intravenously, whereas the wavelength indexes at the end of AF were higher than those before drug administration (1.27 +/- 0.08 vs 1.16 +/- 0.04, p less than 0.05). In conclusion, prolongation of the wavelength appears to be a major determinant for termination of AF, and shorter wavelengths are necessary for perpetuation of AF.

Adult↗
PubMed1992

Comparison between diploid and aneuploid hepatocellular carcinomas: a flow cytometric study.

Nuclear DNA content of hepatocellular carcinoma (HCC) was estimated by flow cytometry after hepatic resection in 91 patients during the past 5 years. There were 53 diploid and 38 aneuploid tumours. Clinicopathological features were compared retrospectively between the patients with diploid and those with aneuploid HCC. DNA ploidy did not show any correlation with age, sex, alcohol abuse, hepatitis B virus, serum alpha-fetoprotein level or underlying liver disease. Histopathologically, the incidence of HCC less than 2 cm in diameter tended to be higher in the diploid group but no difference was seen for large tumours (greater than 5 cm). The grade of tumour differentiation also tended to be higher in this group of small HCC. The ploidy pattern did not influence the rate of capsule or daughter nodule formation, or venous invasion. There were no significant differences in survival rate or in the incidence and time of intrahepatic tumour recurrence between the two groups. This study may indicate that nuclear DNA ploidy is not a particularly predictive factor for the surgical treatment of HCC.

Aneuploidy↗
PubMed1992

Evaluation by colour Doppler and pulsed Doppler sonography of blood flow velocities in intracranial arteries during the early neonatal period.

Using a colour pulsed Doppler flow mapping system, we examined the intracranial arteries of 40 healthy infants. The anterior cerebral, basilar, intracranial internal carotid and middle cerebral arteries were visualized clearly enough to evaluate flow velocity at the success rates of 100%, 87.5%, 65% and 82.4%, respectively. In the anterior cerebral, intracranial internal carotid and middle cerebral arteries, the maximum blood flow velocity slightly decreased to a minimum at around 4-6 h after birth, and then gradually increased. The minimum blood flow velocity pattern was similar. The maximum blood flow velocity in the basilar artery decreased from 0-3 h, rapidly increased from 4-6 h, and remained at a steady level thereafter. A possible mechanism for the chronological changes in the intracranial blood flow velocity is discussed.

Blood Flow Velocity↗
PubMed1992

Changes in plasma catecholamine levels following injection of prostaglandin F2alpha into the basal cistern in rabbits.

We measured plasma epinephrine and norepinephrine concentrations in a rabbit model simulating subarachnoid hemorrhage (SAH), following the injection of prostaglandin F(2alpha) (PGF(2alpha)) into the basal cistern. In this model, plasma epinephrine values increased significantly (to 4.2-fold those before injection), substantially more than norepinephrine (which increased 1.3-fold) at 5 minutes (min) after PGF(2alpha) injection. Dissection of autonomic outflow from the cervical spinal cord or ligation of the suprarenal veins reduced the changes in plasma catecholamine concentrations associated with PGF(2alpha) injection. These results suggest that the sympathetic discharge seen after PGF(2alpha) injection into the basal cistern in rabbits occurred through the sympatho-adrenal pathways.

Journal Article↗
PubMed1992

Clinical characteristics of vascular leiomyoma of the upper extremity: report of 11 cases.

Clinical features of vascular leiomyoma of the upper extremity which have not been described or have been described incorrectly are documented with a report of 11 consecutive cases seen within the past 11 years. All patients were followed without recurrence or surgical morbidity. Vascular leiomyoma has been described as a painful nodule found more frequently on the extensor surfaces, but in our experience spontaneous or paroxysmal pain is exceptional and the tumour tends to be located on the volar surface when it is in the hand. In the digit, they tend to be found at the base away from the midline, and not seen distal to the DIP joint.

Adolescent↗
PubMed1992

Cryopreserved allogeneic vessel and nerve grafts: hind-limb replantation model in the rat.

The authors have previously reported the permanent storage of skin and cutaneous flaps using cryopreservation. In this study, replantation of the hind limb was performed in rats, using an allogeneic femoral artery, vein, and sciatic nerve which had been cryopreserved for more than 3 weeks. Femoral arteries, veins of 2 cm in length, and sciatic nerves of 1.5 cm in length from Lewis rats were cryopreserved for more than 3 weeks to decrease antigenicity. The hind limb of a Brown Norway rat was completely amputated at its mid-length and the cryopreserved artery, vein, and nerve were interposed in the anastomosis of the femoral artery, vein, and sciatic nerve. Immunosuppressants were not used. Hind limbs were replanted in six rats, and all cases survived. Toe spread and gait-foot analysis revealed good results at 3 months postoperatively. Excellent axonal regeneration was observed in the pathologic examination of the sciatic nerve 1 cm distal to the transfer. This report introduces a long-term storage method for vessels and nerves and extends the possibilities for clinical use of cryopreserved vessels and nerves, using replantation in a rat model.

Animals↗
PubMed1992

Enflurane-induced release of an excitatory amino acid, glutamate, from mouse brain synaptosomes.

To clarify the mechanisms of enflurane-induced convulsions, we examined the effects of enflurane, halothane, and diethyl ether on the release of an excitatory neurotransmitter, glutamate, from isolated pinched-off nerve terminals (synaptosomes) of the mouse cerebral cortex. At concentrations corresponding to those used clinically (0.75 and 1.25 mM), enflurane released more glutamate than did halothane. Diethyl ether (10 and 58 mM) had no effect on glutamate release. Enflurane (0.75-15 mM) increased glutamate and aspartate release in a dose-dependent manner but had little effect on the release of the inhibitory neurotransmitters glycine and gamma-aminobutyric acid or on the release of glutamine. A glutamate uptake inhibitor, kainic acid (1 mM), did not affect enflurane-induced glutamate release. Replacement of the medium's Ca2+ by Co2+, or exposure to cold (about 2 degrees C), suppressed the enflurane-induced glutamate release. Depolarization caused by 40 mM K+ increased the basal level of glutamate released, and enflurane-induced glutamate release was lower after depolarization. Enflurane had no effect in synaptosomes prepared from the cerebellum, diencephalon and pons, or medulla oblongata. Thus, enflurane increased Ca(2+)- and temperature-dependent glutamate release, especially from synaptosomes of the cerebral cortex. These data provide a pathophysiologic explanation for enflurane-induced convulsions.

Animals↗
PubMed1992

The salutary effect of FK506 in ischemia-reperfusion injury of the canine liver.

The present study was designed to elucidate the effect of FK506 on 90 min of warm ischemia of the liver and reperfusion in 30 dogs. Three groups of animals were studied. Group 1 animals received FK (0.15 mg/kg/day) for three days prior to the ischemia and group 2 animals got 2 ml of saline solution for three days instead of FK and were considered controls. In group 3 FK (0.15 mg/kg/day) was injected immediately upon reperfusion and two days thereafter. Evaluation of the effectiveness of the drug was monitored by measuring the serum activities of AST, ALT, LDH, serum total bilirubin, malondialdehyde, and by histopathological examinations of the liver specimens and survival of the animals for 7 days after reperfusion. The 7 day survival of the animals in group 1 (80%) was significantly (P < 0.05) improved compared with those in group 2 (30%) and group 3 (20%). The serum activities of AST, ALT, and LDH and total bilirubin were significantly lower in group 1 than in group 2 and group 3. FK pretreatment significantly prevented hepatocellular necrosis and neutrophilic infiltration in group 1 in comparison with those in group 2 and group 3. Although the malondialdehyde level in hepatic venous blood was relatively lower in group 1, this difference was not statistically significant. Three days FK pretreatment prevented hepatocellular injury and enzyme leakage after 90 min of hepatic ischemia, whereas FK treatment immediately upon reperfusion failed to do so. In conclusion, donor organ pretreatment with FK may become a promising strategy for improved allograft survival in liver transplantation.

Animals↗