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T Sankai

Publications and source records attributed to T Sankai.

At least 37 records · Page 2Linked to original sources
PubMed1999

Localization of immunoreactive testosterone and 3beta-hydroxysteroid dehydrogenase/delta5-delta4 isomerase in cynomolgus monkey (Macaca fascicularis) testes during postnatal development.

The age-related expression of testosterone and 3beta-HSD in the testes of cynomolgus monkeys was detected using light-microscopic immunocytochemistry. Intense deposits of immunoreactive testosterone were labeled in parts of Leydig cells in neonatal, late infantile, pubertal, and adult testes, and only a few Leydig cells in early infantile testes. The immunoreactive 3beta-HSD was labeled in parts of Leydig cells and in all Sertoli cells in neonatal, late infantile, pubertal, and adult testes, whereas only a few Leydig cells, but no Sertoli cells, were labeled in early infantile testes. The fluctuations of testosterone and 3beta-HSD expression in testes correlated well with those already observed plasma testosterone levels during postnatal development in cynomolgus monkeys.

3-Hydroxysteroid Dehydrogenases↗
PubMed1999

[Cohort study on risk factors for subarachnoid hemorrhage among Japanese men and women].

PURPOSE: To examine the risk factors for subarachnoid hemorrhage, for few prospective data have been available on risk factors of subarachnoid hemorrhage among Japanese. METHODS: A 9.4-year cohort study was conducted on 12,372 men and women, aged 40-69 years, free of history of stroke in six communities in Japan. RESULTS: During the follow-up, seventy-one incidents of subarachnoid hemorrhage occurred. After adjusting for age, serum total cholesterol, body mass index, history of diabetes mellitus, blood pressure category and drinking category, current smokers had a significantly increased risk of subarachnoid hemorrhage compared with 'never-smokers': multivariate relative risk (RR) [95% confidence interval (95% CI)] = 3.1(1.4-6.9) for women, 1.5(0.4-5.3) for men and 2.7(1.3-5.5)for men and women. Hypertensives had a significantly increased risk of subarachnoid hemorrhage compared with normotensives: multivariate RR(95% CI) = 3.1(1.6-6.0) for women, 4.3(1.5-12.0) for men and 3.4(2.0-5.9) for men and women. For men, heavy drinkers (> = 69 g per day ethanol), had a significantly increased risk of subarachnoid hemorrhage compared with 'never-drinkers': multivariate RR(95% CI) = 4.3(1.1-16.8). For women, the relationship between heavy drinking and risk was not examined due to the small number of heavy drinkers (n = 13). Multivariate RR(95% CI) for men who smoked currently and drank heavily compared with men who did not smoke currently nor drink heavily was 6.0(1.8-20.1). Multivariate RR(95% CI) for hypertensive men who drank heavily compared with normotensive or borderline hypertensive men who did not drink heavily was 13.0(3.9-43.9). Multivariate RR(95% CI) for hypertensive men and women who smoked currently compared with normotensive or borderline hypertensive men and women who did not smoke currently was 6.1(1.3-28.7) for men and 6.3(1.4-28.0) for women. Furthermore, the combination of smoking, hypertension and heavy drinking raised the risk of subarachnoid hemorrhage substantially: multivariate RR(95% CI) = 17.5(3.4-90.2). CONCLUSION: Smoking and hypertension appeared to increase the risk of subarachnoid hemorrhage. For men, although the association of smoking with the risk of subarachnoid hemorrhage was weak compared with women, the combination of smoking, hypertension and heavy drinking increased the risk substantially. For women, smoking appeared to be an independent risk of subarachnoid hemorrhage, and the combination of smoking and hypertension increased the risk in additive fashion.

Adult↗
PubMed1999

[The effects of fish supplementation of platelet function, count and metabolism in healthy Japanese].

To investigate changes in platelet function, count and metabolism following fish intake among Japanese, we conducted an experimental intervention study of seven healthy Japanese volunteers (4 males and 3 females) aged 28-58 years. We supplemented their diets with an approximate daily intake of 200-400 g fish which is equivalent to about 10 g n3-polyunsaturated fatty acids (about 3.5 g eicosapentaenoic acid plus 5.0 g docosahexaenoic acid) during the 17 days. The study continued until the 23rd day after returning to an ad libitum diet. The proportion of serum n3-polyunsaturated fatty acids increased two-fold on 5th day and three-fold on 15th day of fish supplementation, but decreased to one and a half-fold on the 2nd day and returned to the level before fish supplementation on the 12th day after returning to an ad libitum diet. The proportion of serum n6-polyunsaturated fatty acids decreased by 17% to the level before fish supplementation on the 5th day, 33% on the 15th day of fish supplementation. However, the decrease was only 10% on the 2nd day and the proportion returned to the same level as before fish supplementation on the 12th day after returning to an ad libitum diet. As a result, the serum n3/n6 polyunsaturated fatty acid ratio increased four-fold on the 15th day of fish supplementation, and returned to the baseline level on the 12th day after returning to an ad libitum diet. Platelet counts decreased and the mean platelet volume increased during fish supplementation. Both parameters returned to the level before fish supplementation on the 12th day after returning to an ad libitum diet. The counts and proportion of large type platelets increased significantly during fish supplementation. Although platelet aggregation by ADP (adenosine 5'-diphosphate) did not change significantly, platelet aggregation by collagen tended to decrease during fish supplementation. Platelet factor 4, one of the indices of platelet activity, decreased significantly during fish supplementation. The mean serum triglyceride level declined during fish supplementation, but returned to the level just before fish supplementation on the 2nd day after returning to an ad libitum diet. The mean plasma fibrinogen level tended to decline during fish supplementation and remained lower until the 12th day after returning to an ad libitum diet. Habitual fish intake may attenuate the development of atherosclerosis and prevent ischemic heart disease through suppression of platelet activity, and by reducing platelet counts and serum triglyceride levels.

Adult↗
PubMed1999

[Changes in 24-hour urinary excretion of sodium and potassium in a community-based heath education program on salt reduction].

PURPOSE: To examine changes in urinary excretion of sodium, potassium and sodium/potassium ratio in a community-based health education program on salt reduction. SUBJECTS AND METHODS: The surveyed community was Kyowa town (census population in 1985 = 16,792) where we have conducted a community-based blood pressure control program since 1981 and health education on reduction of salt intake since 1983 for primary prevention of hypertension. A 24-hour urine collection was conducted for systematically selected samples of the participants aged 40-69 in cardiovascular risk surveys in 1982-86 (early period) and in 1990-94 (later period) to estimate changes in urine excretion of sodium, potassium, and sodium/potassium ratio. RESULTS: A 24-hour urine collection was available for 565 persons (410 men and 155 women) in 1982-86 and 1,461 persons (571 men and 890 women) in 1990-94. A decline in mean sodium excretion was larger in ages 40-49 than in other age groups, and for ages 40-69 combined, the decline was 0.9-1.1 g per day for men and women. Mean sodium excretion declined to 10 g or less per day for men and women aged 60-69. Mean potassium excretion did not change except for men aged 60-69 with an increase in potassium. Sodium/potassium ratio tended to decline for women aged 40-49, and declined significantly for other sex-age groups. A larger reduction in sodium excretion was seen among persons with a history of hypertension compared to those without it. CONCLUSIONS: A significant reduction in urinary excretion of sodium and sodium/potassium ratio was observed in a community-based health education program. Men and women aged 60-69 reached a recommended level of 10 g or less in sodium intake.

Adult↗
PubMed1998

Alcohol intake and premature coronary heart disease in urban Japanese men.

To examine the relation between alcohol intake and the incidence of coronary heart disease among Japanese, the authors analyzed data from a prospective study of 8,476 Japanese male employees, who were 40-59 years old at baseline (between 1975 and 1984) and worked for 13 urban companies in Osaka, Japan. These men were followed until the end of 1993, on average, an 8.8-year follow-up. Eighty-three coronary heart disease events (54 myocardial infarction, 32 angina pectoris) occurred during the employment period under study. Compared with the risk of coronary heart disease for never drinkers, the age-adjusted relative risk for those with an increased ethanol intake was lower, but the risk did not appear to be reduced further with the intake of > or = 69 g of ethanol per day. The multivariate relative risk adjusted for age, serum total cholesterol, cigarette smoking, body mass index, left ventricular hypertrophy, and a history of diabetes mellitus was 0.83 (95% confidence interval (CI) 0.24-2.86) in exdrinkers, 0.69 (95% CI 0.37-1.29) in drinkers of 1-22 g/day of ethanol, 0.55 (95% CI 0.29-1.05) in drinkers of 23-45 g/day, 0.41 (95% CI 0.19-0.88) in drinkers of 46-68 g/day, and 0.59 (95% CI 0.23-1.51) in drinkers of > or = 69 g/day. The inverse association with alcohol intake was similar between myocardial infarction and angina pectoris. Alcohol intake seemed to prevent the premature incidence of coronary heart disease among urban Japanese middle-aged men.

Adult↗
PubMed1998

Comparison of two methods of assisted fertilization in cynomolgus monkeys (Macaca fascicularis): intracytoplasmic sperm injection and partial zona dissection followed by insemination.

Intracytoplasmic sperm injection (ICSI) and partial zona dissection followed by insemination (PZD-I) were used to establish a microinjection system in cynomolgus monkeys (Macaca fascicularis), which are potential models for human reproduction. Two experimental systems were studied, in which either hamster oocytes or cynomolgus monkey oocytes were used as the vehicle. When hamster oocytes were used, 66 out of 81 ICSI-treated oocytes (82%) showed sperm head swelling or pronucleus formation. Following PZD-I of hamster oocytes the rates of spermatozoa penetration (85/114; 75%) and fertilization (71/114; 62%) were relatively high. When cynomolgus monkey oocytes were used, 19 out of 31 (61%) were fertilized by ICSI with cynomolgus monkey spermatozoa and, subsequently, two embryos (7%) developed to the morula stage. In total, 94% (15/16) of the PZD-I treated oocytes were penetrated by spermatozoa and 63% (10/16) were fertilized. These results demonstrate that both micromanipulation techniques can be used in assisted fertilization with cynomolgus monkeys.

Animals↗
PubMed1998

Localization of testosterone and 3beta-hydroxysteroid dehydrogenase/delta5-delta4-isomerase in cynomolgus monkey (Macaca fascicularis) testes.

The enzyme 3beta-hydroxysteroid dehydrogenase/delta5-delta4-isomerase (3beta-HSD) is essential for the biosynthesis of all classes of steroid hormones, including androgens. We localized testosterone and 3beta-HSD by light microscopic immunocytochemistry in the testes of adult cynomolgus monkeys. Immunoreactive testosterone was located as intense deposits in the labeled cytoplasm of Leydig cells, and located weakly in the interstitial tissues, basement membranes, and the regions near tubular walls within tubules. Immunoreactive 3beta-HSD was located in the cytoplasm of all Sertoli cells and was especially intense in the parts near tubular walls and located weakly to intensely in the cytoplasm of some Leydig cells. This is the first immunocytochemical evidence that Sertoli cells of cynomolgus monkeys, as well as Leydig cells, are involved in biosynthesis of androgens.

Animals↗
PubMed1998

Effects of single and multiple injections of ketamine hydrochloride on serum hormone concentrations in male cynomolgus monkeys.

Using simulated short- and long-term effect studies, we evaluated the effect of ketamine anesthesia on serum cortisol, testosterone, and immunoreactive luteinizing hormone (ILH) and bioactive LH (BioLH) concentrations in adult male cynomolgus monkeys. Cortisol, testosterone, and ILH were measured by use of radioimmunoassay, and BioLH was measured by use of a radioreceptor assay method. For the acute effect, the first group (eight monkeys) was given four successive intramuscular injections of ketamine (10, 5, 5, and 5 mg/kg of body weight at 0, 30, 60, and 110 min respectively). Blood samples were taken at 0, 15, 30, 45, 60, and 120 min. For the long-term effect, the second group (10 monkeys) was given a single injection of ketamine (10 mg/kg) once a week for 4 consecutive weeks. Blood samples were taken 5 to 10 min after each injection, then were used to determine the variation in hormone concentrations among the monkeys (inter-individual variation) and within each monkey (intra-individual variation). There were no statistically significant differences in serum cortisol, testosterone, ILH, and BioLH values between the first blood sample (before the ketamine injection) and sequential blood samples in monkeys of the first group. Although intra-individual variation in the hormones (i.e., hormonal change within each monkey) was not statistically significant, inter-individual variation (among the monkeys) was significantly (0.00001 < P < 0.033) different in monkeys of the second group. These results indicate that an adequate number of animals must be used to minimize animal-to-animal variability. Our results confirm that ketamine is a suitable anesthetic agent to immobilize male cynomolgus monkeys in experimental studies (short- and long-term studies) aimed at elucidating hormonal changes.

Anesthetics, Dissociative↗
PubMed1998

[The relation between platelet aggregation and constitutional and lifestyle variables in two Japanese communities].

To investigate the contribution of the platelet aggregation in the development of cardiovascular diseases, we examined the relation of constitutional and lifestyle variables with platelet aggregation for a total of 306 males aged 50 to 70 in Ikawa town, Akita prefecture (n = 163) and Noichi town, Kochi prefecture (n = 143). The examination of platelet aggregation was completed within 3 hours of obtaining blood samples. We used ADP (Adenosine 5'-diphosphate) as an agonist and obtained PATI (the platelet aggregatory threshold index) by nephelometry. Platelet count, mean platelet volume, white blood cell count, serum fatty acid compositions were also examined and dietary intake of fish, seafood and soy bean foods were inquired using one-week dietary records. PATI indicated a logarithmic normal distribution in both Ikawa and Noichi. The mean of logarithmic transformed PATI (log PATI) was higher in Ikawa than in Noichi. Thus platelet aggregation was lower in Ikawa than in Noichi. According to multiple regression analysis, age, platelet count in platelet rich plasma, mean platelet volume in platelet rich plasma, and white blood cell count were inversely associated with log PATI. Serum arachidonic acid composition tended to be inversely related with log PATI. Serum n3-polyunsaturated fatty acid composition was positively related with log PATI, and log gamma-GTP tended to be positively associated with log PATI. Soy protein intake and cigarette smoking showed no consistent associations with log PATI. This cross-sectional study suggests that serum n3-polyunsaturated fatty acid, and gamma-GTP, as an index of alcohol intake, reduce platelet aggregation while age, white blood cell count, platelet count, mean platelet volume, and serum arachidonic acid raise platelet aggregation.

Age Factors↗
PubMed1998

[Survival and disability in stroke by stroke subtype based on computed tomographic findings in three rural Japanese communities].

PURPOSE: We conducted an epidemiological study of survival and disability in stroke in three Japanese communities to seek community strategies for improvement in survival and disability. METHODS: A total of 297 first-ever strokes were identified between 1988 and 1992 in three rural communities (total population = 47,000) located in Akita and Ibaraki. We analyzed survival rates and activity of daily living by sex, age-group and stroke subtypes. Successful review of computed tomography (CT) for 84 percent of the strokes (249 out of 297) was possible and the data were used for subtype analyses. RESULTS: For all strokes (n = 297) survival rates were 85% for 30 day, 70% for one year, 62% for three year. The rates tended to be lower in women than in men. The rates were lowest in ages less than 60 at thirty day, and in ages 80 and older at the end of the first and third year. Intracerebral hemorrhage with ventricular rupture, subarachnoid hemorrhage and cortical cerebral infarction had lower survival rates than intracerebral hemorrhage without ventricular rupture and lacunar infarction. Based on Cox's proportional hazard model, risk ratio for death was 2.07 in ages 70-79, and 3.80 in ages 80 and older compared with ages 60-69. The risk ratio was 3.46 for intracerebral hemorrhage with ventricular rupture, 3.38 for subarachnoid hemorrhage and 2.46 for cortical cerebral infarction compared with lacunar infarction. The proportion of stroke survivors who need assistance from others in the first and third years tended to be higher in women than in men. The proportion was higher in older patients than in the younger, and higher for intracerebral hemorrhage with ventricular rupture and cortical cerebral infarction than in other subtypes of stroke. From logistic regression analysis, the odds ratio for disability in the first year was 6.55 for ages 80 and older compared with ages 60-69. The odds ratio was 5.61 for intracerebral hemorrhage with ventricular rupture, 4.53 for cortical cerebral infarction compared with lacunar infarction. In the third year the odds ratio was significant for ages 70-79, and decreased for intracerebral hemorrhage with ventricular rupture (odds ratio = 2.98), and increased for cortical cerebral infarction (odds ratio = 6.06). CONCLUSIONS: Survival and disability in stroke depended on age and stroke subtypes. Even after age adjustment, stroke subtypes with large cerebral involvement had worse prognosis than stroke subtypes. Community-based hypertension control programs are important to prevent any subtypes of stroke. Stroke subtypes as well as age should be taken into account to develop effective care and medical treatments for strokes.

Activities of Daily Living↗
PubMed1997

In vitro fertilization and preimplantation embryo development of African green monkeys (Cercopithecus aethiops).

Ovaries of five adult female African green monkeys were stimulated by repeated administrations of equine chorionic gonadotrophin (eCG), followed by a single administration of human chorionic gonadotrophin (hCG). Oocytes were collected from enlarged follicles 28 h after hCG administration and incubated in vitro for 288 h. Oocytes that had extruded the first polar body were inseminated with spermatozoa that had been incubated for 4 to 6 h in medium with caffeine and dibutyryl cyclic AMP. Of these oocytes, 66% were fertilized and the incidence of polyspermy was 37%. Eighty-two percent of the fertilized eggs cleaved, with some developing into expanded blastocysts.

Animals↗
PubMed1997

Changes in normal vaginal flora of African green monkeys (Cercopithecus aethiops) during the menstrual cycle.

Changes in normal vaginal flora of African green monkeys associated with the estrous cycle were examined by the swab method. Bacteroidaceae, corynebacteria, and streptococci were predominant throughout the whole estrous cycle, although individual differences were great. It was also clear that all bacterial species tended to decrease in the menstrual phase. Lactobacilli, the most predominant bacteria in the normal vagina of humans, were detected only in very low numbers in the African green monkey, suggesting that the normal vagina of the African green monkey has a different ecosystem from that of normal human vaginal flora.

Animals↗
PubMed1997

In vitro fertilization of follicular oocytes by frozen-thawed spermatozoa in Japanese monkeys (Macaca fuscata).

We report the cryopreservation of epididymal spermatozoa and in vitro fertilization for Japanese monkeys (Macaca fuscata). Ovarian stimulation of seven monkeys was studied by the administration of equine chorionic gonadotrophin (eCG) and human chorionic gonadotrophin (hCG) during the nonbreeding season, after which oocytes were collected from ovarian follicles. The oocytes were subjected to in vitro fertilization by the frozen-thawed epididymal spermatozoa collected from a male monkey during the nonbreeding season. Before the experiment the epididymides and oocytes were transported about 500 km, during which the epididymides were kept in mineral oil to prevent drying and the oocytes were kept in a maturation medium. This technique of cryopreservation and in vitro fertilization has a wide applicability in nonhuman primate reproduction, including the treatment of infertility and the preservation of wild, nonhuman primates.

Animals↗
PubMed1997

[Effectiveness of a health education class to increase fish intake evaluated by serum fatty acid compositions].

For prevention of cardiovascular disease, we recommended increased fish intake for 50 middle-aged women and men of 40-83 years old at a three-month community-based health education program in an inland farming community. The effectiveness of the education program was evaluated by examining changes in serum lipids and serum fatty acid compositions. For comparison, we selected 48 men and women of 38-82 years old did not participated in the program. Before education, there was no significant difference in the dietary frequency of fish, meat, egg and dishes prepared with oil, mean values of serum lipids or serum fatty acid compositions except for saturated fatty acid, gamma-linolenic acid, dihomo-gamma-linolenic acid and alpha-linolenic acid. After three months, the frequency of fish intake of one or more times per day increased from 33% to 43% in the education group while the frequency of fish intake did not change in the control group. In the education group, serum n3 polyunsaturated fatty acid composition increased from 8.8% to 10.6%. This fatty acid increase was primarily observed in eicosapentaenoic acid and docosahexaenoic acid. The n3/n6 ratio increased from 0.21 to 0.31. In the control group, no change was observed in n3 polyunsaturated fatty acids. This study suggests that the community-based dietary education increased fish intake and serum n3 polyunsaturated fatty acids in women and men of 40 years old or older.

Adult↗
PubMed1996

Community-based education classes for hypertension control. A 1.5-year randomized controlled trial.

Community-based hypertension control is important for primary prevention of cardiovascular disease. In this study, untreated men and women aged 35 to 69 years were randomly assigned to an intervention (n=56) or control (n=55) group in a 1.5-year community-based education program. Subjects had no evidence of hypertensive end-organ defects and had screening blood pressures of 140 to 179 mm Hg systolic and/or 90 to 109 mm Hg diastolic, with no difference in mean blood pressure between groups (148 to 150 mm Hg for mean systolic and 83 to 84 mm Hg for mean diastolic pressures). The intervention group took four education classes in the first 6 months and four classes during the next year, and the control group took two classes. Health education focused on reduced dietary sodium and increased milk intake, brisk walking, and, if necessary, reduction of alcohol and sugar intakes. Antihypertensive medication was started less often in the intervention than in the control group at 1.5 years (9% versus 24%, P <.05). Mean systolic pressure was 5 to 6 mm Hg less in the intervention than in the control group at both 6 months and 1.5 years (P <.05), with or without inclusion of those subjects who began antihypertensive medication. Diastolic pressure and body mass index did not change significantly between groups. Urinary sodium excretion declined in the intervention but not in the control group (differences between groups: P=.04 at 6 months and P=.07 at 1.5 years). According to a behavioral questionnaire, sodium reduction and milk increase were greater in the intervention than the control group (sodium: P <.01 at 6 months and P=.08 at 1.5 years; milk: P <.001 at 6 months and P <.01 at 1.5 years). Mean ethanol intake was reduced in the intervention but not the control group (P=.04 at 1.5 years). This community-based hypertension control program was effective in reducing systolic pressure levels by nonpharmacological means during the first 6 months and maintaining the reduction for 1.5 years.

Aged↗
PubMed1996

Blockade of ovulation in rabbits by RU-486, a competitive progesterone antagonist.

The effect of an anti-progesterone compound, RU-486, administration (20-150 mg) on ovulation in rabbits was investigated. All of the seven control oil-treated rabbits ovulated, whereas, ovulation was blocked in one (12.5%) of eight rabbits treated with 20 mg RU-486, and in 4-6 (66.7-85.7%) of the 6 or 7 rabbits treated with 40-150 mg RU-486. Two successive injections of 10 mg progesterone (P) 4 and 8 hr after RU-486 injection did however recover ovulation in 3 (75.0%) out of 4 rabbits. These results indicate that P secreted from mature follicles during the ovulatory LH surge also play a significant role in follicular rupture of the rabbit, a copulatory ovulator.

Animals↗