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Biomedical subjects

Y Koike

Publications and source records attributed to Y Koike.

At least 343 records · Page 19Linked to original sources
PubMed1984

Visual fixation of caloric nystagmus with special reference to a new index.

The effects of visual fixation upon caloric nystagmus were computed in each parameter as a measure. The percentage reduction established with slow-phase velocity best distinguished normal from abnormal visual fixation at the line of 60%. However, if a +/- 5% safety margin is taken into account, 11 of 176 ears showed false-negatives. The number of nystagmus beats in normals decreased markedly during the period of fixation. In abnormals, the number of nystagmus beats increased definitely during the fixation period. Based on this fact, the product of slow-phase velocity multiplied by the number of nystagmus beats was assessed as the fixation-suppression index. As a result, 11 ears showing false-negative slow-phase velocity decreased to 2 ears. Thus, this modified fixation-suppression index seems to be an appropriate parameter to separate normal from abnormal fixation-suppression of caloric nystagmus.

Adult↗
PubMed1984

[Ultrastructural study of human breast cancer--relation to the basement membrane with invasive breast cancer].

The Japan Mammary Cancer Society's General Rules for Pathological Record prescribe differential diagnosis of the noninvasive or invasive status of human breast cancer upon discovery of basement membrane. We discovered basement membranes not only in normal mammary glands and non invasive breast cancers, but in metastatic breast cancers to the lungs and regional axillary lymph nodes. We concluded that, for such diagnosis, it is necessary to observe the cellular arrangement and condition of the surrounding stromal tissues with light microscopy. Nuclear chromatin patterns should also be examined; they showed predominantly euchromatin in invasive breast cancer and heterochromatin in non-invasive breast cancer with electron microscopy.

Adult↗
PubMed1984

[A chronobiological study of behavioral changes in rats].

A chronobiological study of behavioral changes in Wistar Kyoto rats (WKY), spontaneously hypertensive rats (SHR) and stroke prone spontaneously hypertensive rats (SHRSP) was undertaken. Attention was focused on changes in ambulatory activity and drinking behavior using an Ambulo-Drinkometer, the effects of centrally acting antihypertensive drugs, and the relationship between behavioral changes and humoral factors. (1) The experiment was performed during a light-dark alternation cycle. Approximately 10 days were required for rats to acclimate to new cages. (2) Using power spectral analysis, a 24 hr periodicity was dominant in both sexes of WKY and SHRSP. A 120 hr periodicity was demonstrated in female SHRSP. This long periodicity may have been due to a female sexual rhythm. (3) Ambulatory activity of WKY and SHRSP tended to decrease with age. (4) After abrupt cessation of clonidine administration, an ambulatory ultradian rhythm was demonstrated. Guanfacine treated SHR showed less change in ambulatory ultradian rhythm than clonidine treated SHR. (5) Using a Drinkometer with attached metabolic cages, drinking counts, urinary volumes, urinary aldosterone and catecholamine excretion rates were higher during the dark phase than during the light phase. It was demonstrated that analysis of rhythmicities and measurement of behavioral amplitude are both needed in the study of behavioral pharmacology.

Acclimatization↗
PubMed1983

Acute and chronic effects of verapamil in patients with paroxysmal supraventricular tachycardia.

Efficacy of acute intravenous verapamil, 10 mg, and chronic oral verapamil, 320 mg, daily were studied electrophysiologically in 15 patients with paroxysmal supraventricular tachycardia (PSVT). Plasma verapamil concentrations were measured concurrently. Both intravenous and oral verapamil significantly increased the AV node conduction time, the cycle length producing a Wenckebach period, and the refractory period of the AV node. These changes were reflected in changes in plasma verapamil concentration. The echo zone and the supraventricular tachycardia (SVT) zone markedly narrowed after administration of both intravenous and chronic oral verapamil. Verapamil's efficacy was found to be related to the type of SVT. For instance, verapamil was more effective in SVT due to AV nodal re-entry than in SVT due to concealed accessory pathway. Fourteen patients were followed from 3 to 31 months and all except one were well controlled. In conclusion, verapamil was effective in prophylaxis of paroxysmal SVT.

Administration, Oral↗
PubMed1983

Evaluation of alaryngeal voice quality by nonparametric procedures.

Alaryngeal voice quality was evaluated based on nonparametric statistics. Twenty voice samples of the vowel /e/ were recorded from sixteen alaryngeal and four normal speakers, and were randomized and presented to twenty normal listeners. The listeners rated the voices using seven-point scales consisting of twelve pairs of polar-opposite adjectives. By means of nonparametric procedures such as the Wilcoxon signed rank test, significant differences in the rating scores were detected for certain combinations of the voice samples, the classes of voicing methods, the listeners and the rating scales. Quality of the alaryngeal voices differed significantly from that of the normal voices on some of the rating scales. The results suggest the nonparametric procedures are useful to evaluate alaryngeal voice quality.

Adult↗
PubMed1983

Plasma norepinephrine concentration and plasma dopamine-beta-hydroxylase activity in patients with congestive heart failure.

The relationship between plasma norepinephrine (NE), epinephrine (E) and dopamine-beta-hydroxylase activity (DBH) was studied in 90 cardiac patients (New York Heart Association [NYHA] classes I-IV), 85 healthy control subjects and 18 competitive skiers. The cardiac patients in NYHA classes III and IV had significantly higher NE (p less than 0.001) and lower DBH (p less than 0.001) levels than the controls, whereas the skiers had significantly lower NE (p less than 0.001) and higher DBH (p less than 0.05) levels than the controls. Seven cardiac patients in whom successful cardiac surgery was performed had decreased NE (p less than 0.001) and increased DBH (p less than 0.02), as well as significantly improved NYHA cardiac status (p less than 0.001). These findings demonstrate an inverse relationship between NE and DBH in a population of athletes, normal subjects and cardiac patients; the same inverse relationship holds for these patients when sequential studies are done after a change in cardiac status.

Adolescent↗
PubMed1982

Studies on DNA content of hepatocytes in cirrhosis and hepatoma by means of microspectrophotometry and radioautography.

In order to clarify the underlying mechanism of malignant transformation from cirrhosis to hepatoma the cell kinetics of hepatocytes were studied in these two conditions. The content and synthesis of DNA in hepatocyte nuclei were investigated, by means of Feulgen-microspectrophotometry and tritiated thymidine radioautography, in cirrhotic and noncancerous parts of hepatoma with concomitant cirrhosis. The distribution of ploidy patterns was widely spread, from hypodiploid to hyperpolyploid, in the noncancerous parts of a cirrhotic liver containing hepatoma. In normal liver, each paired nuclear DNA content of a binucleate cell recorded almost the same amount, whereas in the noncancerous as well as in hepatoma cells much difference of DNA content was observed between the paired nuclei of the binucleate cells. The ploidy pattern of hepatocytes in patients with liver cirrhosis, who had developed hepatoma during follow-up periods of several months to several years, appeared to resemble that in noncancerous parts of hepatoma cases. On the other hand, the incorporation of tritiated thymidine into hepatocytes was found to be markedly increased in noncancerous parts as well as in cirrhotic liver developing hepatoma during follow-up periods. These results suggest the possibility that the hepatocytes in noncancerous parts of hepatoma have deranged cell-kinetics which might be a driving factor for the development of malignancy.

Acute Disease↗
PubMed1982

Effects of clonidine and guanfacine on drinking and ambulation in spontaneously hypertensive rats.

Present experiment was undertaken to compare the effects of clonidine and guanfacine on water drinking behavior and ambulatory activity in spontaneously hypertensive rats (SHR). Equipotent hypotensive doses of clonidine and guanfacine, 150 micrograms/kg and 1500 micrograms/kg, respectively, given twice a day at 8:00 and 20:00, produced a triphasic pattern of behavioral changes; initial increase in water drinking and ambulation during the light period, decrease in water intake and ambulation at the beginning of the dark period, and a second increase in water drinking and ambulation at the end of the dark period. Guanfacine treated SHR showed less change in water drinking behavior and ambulation than the clonidine treated SHR.

Animals↗
PubMed1982

The significance of blood transfusion in non-A, non-B chronic liver disease in Japan.

We performed a follow-up study on 70 patients with acute non-A, non-B (NANB) posttransfusion hepatitis and a retrospective study on 283 chronic hepatitis, 70 cirrhosis and 53 hepatocellular carcinoma patients of type NANB. In acute NANB post-transfusion hepatitis, as judged by the transaminase levels, th duration of the disease exceeded 6 months in 46/70 = 65.7% and 1 year in 32/70 = 45.7%. The histological diagnosis of the 32 cases persisting for more than 1 year was chronic active hepatitis in 5, chronic persistent hepatitis in 2 and unresolved hepatitis in 6. The frequency of previous transfusion in chronic hepatitis, cirrhosis and hepatocellular carcinoma of type NANB was 42.8, 37.1 and 15.1%, respectively, whereas the incidence of early posttransfusion hepatitis was 8.5, 8.6 and 7.5%, respectively. in chronic liver diseases with a history of jaundice and/or hepatitis, previous transfusions are more frequently associated with type NANB than with type B disease. The present study demonstrates that NANB posttransfusion hepatitis tends to develop to chronic liver disease when analyzed prospectively as well as retrospectively.

Adult↗