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Biomedical subjects

K Aoki

Publications and source records attributed to K Aoki.

At least 487 records · Page 27Linked to original sources
PubMed1993

[Effects of quinapril on the development of hypertension, cardiac hypertrophy and stroke in salt-sensitive Dahl rats and stroke-prone spontaneously hypertensive rats].

The effects of repeated administration of quinapril (10 mg/kg/day) on the development of hypertension, cardiac hypertrophy and survival rate were examined, and compared with those of enalapril (10 mg/kg) in salt-sensitive Dahl (Dahl S) rats and 1% saline-loaded stroke-prone spontaneously hypertensive rats (SHRSP). The Dahl S rats were treated with the drugs at 10 to 20 weeks of age and the SHRSP, at 8-19 weeks of age. (1) In the Dahl S rats, salt loading rapidly raised systolic blood pressure, which was around 220 mmHg at 10 weeks of age. Both quinapril and enalapril significantly prevented the development of hypertension (below 160 mmHg) and cardiac hypertrophy. Age-associated histopathological alterations in the kidney and mesenteric artery in Dahl S rats were suppressed by the drug treatment. (2) Salt-loaded SHRSP rapidly developed severe hypertension (270 mmHg at 12 weeks of age) accompanied with stroke signs, and 19 animals out of 20 died by the end of the experiment. Both quinapril and enalapril significantly inhibited the age-associated development of hypertension and markedly improved the survival rate (only two animals out of 16 died in both groups). These results suggest that quinapril has protective actions against age-associated development of hypertension and cardiac hypertrophy, and as a result, it prolongs the life span.

Animals↗
PubMed1993

[Antihypertensive activity of the angiotensin converting enzyme inhibitor quinapril HCl: (S)-2-[(S)-N-[(S)-1-ethoxycarbonyl-3-phenylpropyl) alanyl]-1,2,3,4- tetrahydro-3-isoquinolinecarboxylic acid monohydrochloride in various hypertensive animal models].

The antihypertensive activity of quinapril was examined in normotensive and various hypertensive animal models. In 2-kidney, 1-clip renal hypertensive rats (2K-RHR), quinapril (0.1 to 1.0 mg/kg, p.o.) had a dose-related and sustained antihypertensive action, which was as potent as that of enalapril and approximately 40 times stronger than that of captopril. Heart rate was not changed by these doses of quinapril. In spontaneously hypertensive rats (SHR) and 1-kidney, 1-clip renal hypertensive rats, quinapril as well as enalapril dose-dependently produced a significant fall in blood pressure. The relative potency and duration of the effect of quinapril was the same as that of enalapril in these models. Quinapril at 30 mg/kg, p.o. lowered blood pressure and increased heart rate in normotensive rats. In contrast, quinapril and enalapril failed to reduce blood pressure in DOCA/salt hypertensive rats. In the repeated dose study, no development of tolerance was observed during the administration period in 2K RHR and SHR. The antihypertensive effects in 2K RHR was greater than those in SHR. Quinapril was more potent and long-lasting than enalapril in 2K RHR and SHR. From these results, quinapril is expected to be useful for the clinical treatment of hypertension.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1993

[Effect of palonidipine hydrochloride (TC-81), a new dihydropyridine derivative, on various myocardial ischemic models].

The antianginal effects of palonidipine, a novel 1,4-dihydropyridine derivative, and nifedipine on various myocardial ischemic models were compared. (1) Palonidipine at 0.5 mg/kg, p.o. significantly inhibited vasopressin-induced ST depression of ECG in Donryu rats. This activity was about 5 times more potent than that of nifedipine and was long-lasting. (2) Palonidipine at 1 mg/kg, i.d. significantly inhibited ST depression induced by isoproterenol in Wistar rats. This activity of TC-81 was more potent than that of nifedipine. (3) Palonidipine at 3 micrograms/kg, i.v. produced an increase in regional myocardial tissue blood flow in the ischemic region of chronic coronary artery occluded dogs. (4) In isolated dog coronary artery, palonidipine at a concentration of 10(-10) M or greater inhibited the amplitude of 3,4-DAP-induced cyclic contractions in a concentration-dependent manner. This activity was 10-30 times more potent than that of nifedipine. (5) An intracoronary injection of endothelin (30 pmol/kg) reduced the coronary blood flow, subepicardial tissue blood flow, and subepicardial pH in anesthetized dogs. The ST elevation of ECG over 0.1 mV also occurred in 8 of 10 cases. In all the cases, ventricular extrasystoles were noted, and 9 out of 10 animals died. Pretreatment with palonidipine (3 micrograms/kg, i.v.) inhibited endothelin-induced ischemic changes, with a potency greater than that of nifedipine. These results suggest that palonidipine may be useful for the therapy of angina-pectoris.

Angina Pectoris↗
PubMed1993

[A study on the primary prevention of essential hypertension (1). Evaluation of blood pressure response during exercise and effect of habitual exercise].

Hypertension is one of the risk factors of cardiovascular diseases, which are widely prevalent maladies that result in burdensome medical expenditures. Therefore, it is important to explore primary preventive measures for hypertension. Until recently, it was thought that exercise was a risk factor for hypertension, but recent reports have suggested that low-intensity physical training actually lowers blood pressure. However, habitual physical exercise has still not been clearly proven to prevent the development of hypertension. To clarify this point, one must first establish a method for predicting hypertension and second examine the possibility of preventing the development of hypertension by changing the subject's environment. In this study we have investigated a method for predicting hypertension by classifying blood pressure responses to increasing exercise intensity and the effect of habitual exercise on blood pressure response. This study was composed of three experiments. Experiment one involved female students (n = 42) and experiment two, male students (n = 38), in whom blood pressure response rates during exercise were recorded. In experiment three, the same group of female students (n = 23) was subjected to training in order to chart its effects on blood pressure response, both while exercising and while at rest. The exercises were performed with a bicycle ergometer in an upright position. There were four different degrees of work intensity. Blood pressure was measured using the auscultation method, with Riva-Rocci mercury measured by the same investigator. High blood pressure responses at rest were noted among some normotensive female and male students. The systolic blood pressure responses during the peddling exercise showed significant individual differences at the lowest work load; the distribution of the increment of the systolic blood pressure ratio at the lowest work load against the increment while resting showed two peaks. This result suggests that this increment ratio is an important variable related to the prediction of hypertension. The increment ratio showed no significant change in female students after three months of aerobic exercise. The high-response group showed high readings of the TPR indicator (MBP/VO2). Aerobic training was shown to be effective in significantly lowering the TPR indicator both at rest and during exercise. This result suggests that habitual exercise may contribute to preventing the development of hypertension.

Adult↗
PubMed1993

[Relationships among physical activity, physical fitness and coronary risk factors in adult women--comparison between premenopausal and postmenopausal women].

The relationships among daily physical activity, physical fitness and the risk factors for coronary heart disease (CHD) were studied comparing 477 premenopausal women (36.1 +/- 7.6 yr) and 178 naturally postmenopausal women (56.7 +/- 5.8 yr). The results were as follows. 1) No relationship between physical fitness and daily activity level was found in either groups. 2) In premenopausal women, daily activity was associated with blood pressure, triglycerides (TG) and blood sugar only in the low-fitness group. But there was no relation between risk factors and the level of daily activity in the high-fitness group. 3) In postmenopausal women, the low-fitness group showed increasing TC/HDLC and decreasing HDLC associated with the low daily activity. TC, LDLC and TC/HDLC were lower in the high-fitness-with-high-daily-activity group than in the high-fitness-with-low-daily-activity group. 4) In both groups, the levels of TG and TC/HDLC were lower in the high-fitness group than in the low-fitness group. This suggests that serum lipids have a closer relation to fitness than to daily activity. These results indicate that the relationships among daily activity, physical fitness and CHD risk factors are different in menopausal status, and that daily activity is one of the most important factors to reduce CHD risk factors, especially in unfit or postmenopausal women.

Activities of Daily Living↗
PubMed1993

Glucocorticoid therapy decreases serum lipoprotein(a) concentration in rheumatic diseases.

Lipoprotein(a) has been strongly suggested to be a risk factor for atherosclerosis. However, its metabolism and/or regulation by drug treatment still remain unknown. We therefore studied the effects of glucocorticoid therapy on serum lipoprotein(a) in rheumatic diseases. Although the glucocorticoid treatment increased the total serum cholesterol, high-density lipoprotein cholesterol and apolipoprotein B concentrations, it reduced the serum lipoprotein(a) concentration (mean, 40%) in a dose-dependent manner in 9 patients with rheumatic diseases without nephrotic syndrome. Similar results were observed in 2 patients who did have nephrotic syndrome. It is assumed that the increase of total cholesterol and apolipoprotein B in serum levels are atherogenic, whereas the increase of high-density lipoprotein cholesterol and the decrease of lipoprotein(a) are protective for atherosclerosis. The clinical outcome of the concomitant results in lipid metabolism in the development of atherosclerosis remains to be studied.

Adolescent↗
PubMed1993

Integrin VLA-5 negative primary plasma cell leukemia.

We present a case of primary plasma cell leukemia with Bence Jones proteinuria. After combination chemotherapy, leukemic cells and the urinary levels Bence Jones protein were decreased. Small lytic bone lesions were detected only in the skull. Typical plasma cells were rarely seen in peripheral blood on the hyperleukocytic phase, however they were increased in the advanced stages. The most important diagnostic sign was persistent expression of CD38 antigen on leukemic cells throughout the entire course of the illness and these leukemic cells expressed very late antigen-4 (VLA-4) but not VLA-5.

ADP-ribosyl Cyclase↗
PubMed1993

Follow-up examination schedule of postoperative HCC patients based on tumor volume doubling time.

The tumor volume doubling time of 27 recurrent hepatocellular carcinoma nodules measuring < or = 2.0 cm in diameter discovered after hepatectomy in 19 patients was analyzed by ultrasonography for 31 to 331 days. The tumor volume doubling time ranged from 39 to 420 days before specific treatment, with a mean of 112 days and a median of 80 days. It correlated with age and intrahepatic site of recurrence, which was sometimes the same lobe as that of the prior hepatocellular carcinoma, sometimes not. The tumor volume doubling time also tended to correlate with hepatitis C antibody status and initial tumor diameter. The tumor volume doubling time was, however, independent of sex, hepatitis B surface antigen status, number of recurrent tumors, initial serum alpha-fetoprotein level, interval between hepatectomy and recurrence detection, and associated liver disease. On the basis of the shortest tumor volume doubling time of the recurrent hepatocellular carcinoma nodules, we recommend that US and/or CT be performed at least every four months to screen for small recurrent carcinomas in postoperative patients.

Aged↗
PubMed1993

Combined hepatocellular carcinoma and cholangiocarcinoma: clinical features and computed tomographic findings.

Clinicoradiological features were studied in 20 patients with 22 mass lesions of combined hepatocellular carcinoma and cholangiocarcinomas and findings of computed tomography in 12 of these patients with 14 hepatocellular carcinoma-cholangiocarcinomas. Five of these patients also had single overt hepatocellular carcinomas. The incidence of hepatocellular carcinoma-cholangiocarcinoma was 3.3% among the patients with primary liver cancer treated in our hospital. HBsAg was present in 25%, and increased levels of serum alpha-fetoprotein (> 200 ng/ml) and carcinoembryonic antigen (> 5 ng/ml) were found in 25% and in 47%, respectively. Associated cirrhosis was present in 60%. Analysis of 14 hepatocellular carcinoma-cholangiocarcinomas in 12 patients in whom the enhancement pattern on dynamic computed tomography and pathological findings could be studied and compared suggested three tumor types. Nine lesions (type A) were demonstrated only as areas with high-density peripheries in the early phase of enhancement that evolved into a pattern of peripheral low density and central high density in the late phase. Four masses (type B) were shown as hyperdense tumors (early phase) that changed to low density in the late phase. One mass (type C) was seen as a low-density lesion that did not change. Histopathologically, type A comprised hepatocellular carcinoma-predominant components in the peripheral area, cholangiocarcinoma-predominant components with abundant fibrous stroma in the central area and a tissue transitional between the two in the midzone. By contrast, two of four type B masses comprised hepatocellular carcinoma with scattered cholangiocarcinoma components throughout the tumor.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

[Analysis of continuous ambulatory peritoneal dialysis (CAPD) stressors in CAPD patients].

The purpose of this study is to clarify stressors resulting from continuous ambulatory peritoneal dialysis (CAPD) in CAPD patients and to discuss adaptation to daily life. With reference to the dialysis stressor scale used by Baldree and Masaki et al., a scale for CAPD stressors, consisting of 42 items, was devised, and the stressors were investigated in 56 patients, with the following results: 1) The items rated as high CAPD stressors included the frequency of bag exchange, itch, fatigue, anxiety about the future, and restricted physical activities. Restriction of meal and fluid intake, which are highly-rated stressors in patients on hemodialysis (HD) were not highly-rated stressors in these 56 CAPD patients. Thus, there was a difference between HD and CAPD. 2) The degree of cognition of CAPD stressors increased according to an individual's situation. (1) The presence or absence of an occupation had the greatest effect on the cognition of CAPD stressors. (2) The degrees of cognition of anxiety about the future and work-related difficulties as stressors were high in patients under 60 years of age. (3) The degree of cognition of items related to work as stressors was high in male patients while that of items related to body image as stressors was high in female patients. (4) There was a qualitative difference in stressor congnition between patients with a history of CAPD of shorter than 3 months and those whose history was 3 months or longer. (5) The degree of congnition of infection was also low in patients who suffered from peritonitis. (6) The degree of congnition of symptoms causing physical discomfort was high in patients with diabetic nephropathy. (7) There were significant differences in several variables, in terms of the degree of congnition, among patients with regard to work difficulties and the absence of familial cooperation. On the basis of these results, guidance for patients and their families is necessary.

Adaptation, Psychological↗
PubMed1993

Mutation induction by different dose rates of gamma rays in near-diploid mouse cells in plateau- and log-phase culture.

Induction of mutation to 6-thioguanine resistance was studied in cultured near-diploid mouse cells (m5S) in plateau and log phase after exposure to gamma rays at dose rates of 30 Gy/h, 180 mGy/h, or 13 mGy/h. In plateau-phase culture, lowering the dose rate from 30 Gy/h to 13 mGy/h resulted in an increase in cell survival and a marked decrease in induced mutation frequency. On the other hand, in the log-phase culture, the magnitude of the dose-rate effects was not as marked as in the plateau-phase culture, particularly within a dose range below 5 Gy. These results, together with those indicating the inverse dose-rate effects in growing mouse leukemia cells (Radiat Res. 115, 273-280, 1988), demonstrate the significant influence of cell growth that takes place during protracted irradiation, particularly for the induction of mutation.

Animals↗
PubMed1993

[A sporadic case of late onset familial amyloidotic polyneuropathy preceded by cardiac involvement].

We report a 65-year-old man with amyloidotic polyneuropathy, who first suffered from heart failure at the age of 57, 3 years before the onset of neurological symptoms. He had no obvious family history. We analysed the transthyretin gene of the patient and 6 asymptomatic family members using polymerase chain reaction (PCR). The single amino acid substitution of a methionine for valine at position 30, which is a common mutation of Japanese type I FAP patients, was found from the patient and his sister of 47 years. Though Type I FAP patients often have cardiac conduction block, they rarely have signs of heart failure until the end stage of the disease. This is the first report of Type I FAP with severe myocardial involvement, in which TTR mutation at position 30 was confirmed. The result revealed the clinical variation of Type I FAP.

Aged↗
PubMed1993

Liver abscess after percutaneous ethanol injection (PEI) therapy for hepatocellular carcinoma. A case report.

We present a case of liver abscess after percutaneous ethanol injection (PEI) therapy for the treatment of recurrent hepatocellular carcinoma (HCC). The 56-year-old woman had a past history of cholecystoduodenostomy for cogenital dilatation of the bile duct, and pneumobilia was observed in the intrahepatic bile ducts prior to PEI. The abscess was successfully treated by percutaneous abscess drainage and antibiotic therapy. Klebsiella pneumonia, one of the most common causative organisms of biliary tract infection, was isolated from the abscess. Thus, biliary tract infection related to the previous biliary-enteric anastomosis operation may have been one of the causative factors in the liver abscess in this patient. The rare experience reported here suggests that a careful search for coexistent abscess at the time of PEI is important in HCC patients with biliary-enteric anastomosis, especially in those with pneumobilia.

Carcinoma, Hepatocellular↗
PubMed1993

[Distribution of serum pepsinogen I, II values and their ratios in residents of a rural area].

In order to adopt pepsinogen levels as a screening indicator of gastric cancer, the serum pepsinogen I (PG I) and serum pepsinogen II (PG II) levels were studied using one thousand samples from a rural area and their ratios PG I/PG II were calculated. Samples were collected by stratified random sampling of the residents in S town with a population of about 10,000. The collected data was statistically analyzed to determine distributions by respective categories of sex and age. The following results were obtained. 1. The distributions of PG I, PG II and their ratio PG I/PG II levels largely deviated from normal distributions. Therefore, it is recommended that non-parametrical method is used to analyze this data. 2. The median of PG I level (49.3 micrograms/l) in males was statistically higher than that (43.6 micrograms/l) in females. On the other hand, a statistically significant difference between males and females was not observed in either the PG II value or the ratio PG I/PG II, respectively. 3. The pattern for changes in PG I values with age was different between males and females. While PG I levels were almost constant until the sixties, after the seventies levels showed a marked decrease in male subjects. In female subjects, an age effect in levels was not observed for PG I. On the other hand, PG II levels increased with age except for age group seventies, and the PG I/PG II ratios showed a decreasing tendency in both males and females.

Adult↗
PubMed1993

[Serological diagnosis of adenovirus conjunctivitis].

We compared the serum antibody titers against adenoviruses of pair sera and the identification of isolated adenovirus from 17 patients with acute conjunctivitis. Isolated adenoviruses were Ad3 in ten cases, Ad8 in four cases, Ad37 in two cases, and Ad4 in one case. Among these cases, eleven cases showed identical results in a neutralization test. In one patient from whom Ad3 was isolated, no neutralizing antibody was found. In 3 patients from whom Ad8 or Ad37 was isolated, there were discrepancies between serological results of the neutralization test or the haemagglutination inhibition test, and viral isolation. Antibody titers against adenoviruses subgenus D, such as Ad8, 19 and 37 were increased not only for the isolated serotypes, but also for other serotypes of this subgenous.

Adenovirus Infections, Human↗
PubMed1993

[Effects of 12wk-exercise walking on serum lipids, lipoproteins and apolipoproteins in middle aged women--does menopause status influence training effects?].

The present study examined the effects of 12wk-exercise walking on serum lipids in pre- and post-menopausal women, to elucidate the influence of menopausal status on the training effects. Twenty one premenopausal women (42.2 +/- 5.6 yr) and seventeen postmenopausal women (56.7 +/- 6.9 yr) participated in a 12 wk-walking program. Self-monitored exercise walking was performed 3 or 4 times per week in sessions of 45 minutes. Average intensity of the exercise was 57% HRmax in the premenopausal group (Pre-M) and 65.5% HRmax in the postmenopausal group (Post-M), respectively. After adjustment for age, baseline value of apolipoprotein AI (Apo AI) was significantly lower and total cholesterol (TC) and low density lipoprotein cholesterol (LDLC) were higher in Post-M than in Pre-M. After 12 weeks, percent body fat decreased significantly in both groups and BMI decreased in Pre-M. Physical fitness tended to increase only in Pre-M. The increase of high density lipoprotein cholesterol (HDLC) and the decrease of Apo AI, Apo B, TC/HDLC were significant in both groups. The decrease of TC, LDLC, Apo B and TG and the increase of HDLC were common changes in both groups, even after adjusting for baseline values, change in body composition, exercise intensity and total exercise time. Change volume of TG tended to be larger in Pre-M than in Post-M. Results of multiple regression analysis showed that the change in serum lipids, especially cholesterol, correlated to initial values, change in body composition and change in fitness, in Post-M but not in Pre-M.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Excess incidence of lung cancer among pulmonary tuberculosis patients.

Reviewing the epidemiological studies on coexistent pulmonary tuberculosis and lung cancer since 1960, it was confirmed that patients with active pulmonary tuberculosis have a higher risk of dying from lung cancer or other malignancies, in spite of a very high mortality from tuberculosis per se. Females showed a higher risk than males. An antagonistic hypothesis between the above two diseases since 1854 seemed based on the facts that tuberculosis patients had mostly died in young age groups and had had little chance of surviving to cancer age groups before the advent of modern treatments, and that the lack of an adequate disease registration system might have caused a failure to reveal any association between the two diseases. Specific causative factors of the excess incidence of cancer among active pulmonary tuberculosis patients, however, have so far not be clarified.

Female↗