Sperm replacement in sperm-storage tubules causes last-male sperm precedence in chickens.

1. This study elucidated the last-male sperm precedence (LMSP) mechanism in chickens by examining replacement in storage tubules (SSTs) after multiple artificial inseminations (AI) and the effects of seminal plasma (SP) and male breed on sperm replacement in SSTs.2. Hens were artificially inseminated with fluorescent dye-labelled spermatozoa from White Leghorn (WL) chickens. Secondary AI was conducted 3 d later with sperm labelled with different nuclear fluorescent dye. Percentage of first and second inseminated sperm in SSTs and their logarithmic odds were calculated. The effect of SP on LMSP was examined using (1) Lake's solution-washed sperm before second insemination, and (2) SP injected continuously after first insemination. Effect of breed difference on sperm replacement was investigated using Barred Plymouth Rock (BP) sperm.3. Successive WL-sperm inseminations at three-day intervals caused > 70% stored sperm replacement in SSTs. Although SP removal from sperm from second insemination significantly decreased replacement, its intra-vaginal injection did not affect release. Secondary insemination using BP sperm significantly increased replacement.4. Sperm replacement is a major factor favouring LMSP in domestic chickens. Two fluorescent staining of sperm, and intra-vaginal multiple AI technique have enabled visualisation, differentiation, and quantification of multiple inseminated sperm stored in the SSTs.

Determination of the Avogadro constant by counting the atoms in a 28Si crystal.

The Avogadro constant links the atomic and the macroscopic properties of matter. Since the molar Planck constant is well known via the measurement of the Rydberg constant, it is also closely related to the Planck constant. In addition, its accurate determination is of paramount importance for a definition of the kilogram in terms of a fundamental constant. We describe a new approach for its determination by counting the atoms in 1 kg single-crystal spheres, which are highly enriched with the 28Si isotope. It enabled isotope dilution mass spectroscopy to determine the molar mass of the silicon crystal with unprecedented accuracy. The value obtained, NA = 6.022,140,78(18) × 10(23) mol(-1), is the most accurate input datum for a new definition of the kilogram.

Fertilization and blastoderm development of quail oocytes after intracytoplasmic injection of chicken sperm bearing the W chromosome.

Our previous study demonstrated that elongated spermatids and sperm carrying the female-specific W-chromosome of the sex-reversed domestic fowl can activate the mouse oocyte, but whether they can fertilize the avian oocyte and lead to a developing zygote remains undetermined. A single sperm isolated from the semen and testis of normal rooster and from a testis of sex-reversed hen was microinjected into a quail oocyte and cultured for 20 to 24 h. Blastoderms were fixed, cleaved, nuclei stained by 4',6'-diamidino-2-phenylin-dole, and developmental stages were assessed. In the normal rooster group, ejaculated and testicular sperm induced blastodermal development in 22.6 and 20% of the quail oocytes, respectively. The developmental stages ranged from IV to VII. In the sex-reversal group, 20% of injected testicular sperm induced blastodermal development. The blastodermal stages varied from stage III to VI. Blastoderms after 4',6'-diamidino-2-phenylindole staining were assayed by PCR to identify the W chromosome of either chicken sperm or quail oocyte. The PCR assay results showed that 2 out of 9 developed blastoderms microinjected with sperm of sex-reversed hen were identified containing the female-specific W chromosome derived from sex-reversed hen. From these results, it is concluded that chicken sperm bearing the W chromosome possess fertilizing ability and can function to stimulate blastoderm development similar to that of normal chicken sperm carrying the Z chromosome.

Distribution of twenty-four hour urinary taurine excretion and association with ischemic heart disease mortality in 24 populations of 16 countries: results from the WHO-CARDIAC study.

There is considerable interest in the association between taurine (2-aminoethanesufonic acid) and risk of ischemic heart disease (IHD), but little information has been made available on the distribution of taurine in populations around the world. The present study aimed to describe the differences in taurine excretion levels and their associations with IHD mortality rates in 24 populations in 16 countries worldwide. This was a multicenter cross-sectional study. In each center, 100 men and 100 women aged 48-56 years were selected randomly from the local populations. Twenty-four hour urinary taurine excretion was measured using an amino acid analyzer (Hitachi 835, Ibaragi, Japan). Age-adjusted IHD mortality rates in the relevant populations were calculated using the direct standard method. The results indicated that (a) percentiles 25%, 50% and 75% of the distributions of 24-h taurine excretion showed large variations in the study populations. Median values of taurine ranged from 191.6 micromol/day (St John, Canada) to 2,180.6 micromol/day (Beppu, Japan) in males, and from 127.5 micromol/day (Moscow, Russia) to 1,590.0 micromol/day (Beppu, Japan) in females. The highest overall median value of taurine was found in the Japanese population samples, followed by the Chinese samples (Shanghai and Taiwan). European, North American and oceanic Caucasians, however, had much lower median values of taurine, except in the cases of the samples from France and Spain. (b) Median values of taurine were significantly associated negatively with age-adjusted IHD mortality rates across the 24 study population samples in men (R2=0.42, p<0.01), and in women (R2=0.55, p<0.01). These negative associations remained significant after adjustment for serum total cholesterol, body mass index and urinary sodium to potassium ratios. In conclusion, the study provides, for the first time, a cross-sectional database on distribution of 24-h urinary taurine excretion in 24 population samples worldwide. A strong and inverse association between population levels of taurine excretion and IHD mortality was observed.

Ethnic and environmental differences in various markers of dietary intake and blood pressure among Chinese Han and three other minority peoples of China: results from the WHO Cardiovascular Diseases and Alimentary Comparison (CARDIAC) Study.

Our aim was to examine differences in dietary intake and blood pressure (BP) and their associations in four different ethnic Chinese populations, the Han, the Uygur, the Kazak and Tibetan subjects. This study used a sub-database of the Chinese sample of the WHO-Cardiovascular Diseases and Alimentary Comparison (CARDIAC) Study. The WHO-CARDIAC Study was a multicenter cross-sectional study. In each center, 100 men and 100 women aged 48-56 years were selected at random from the local population. Various markers of dietary intake and their relation with BP were studied. The results of the present study indicated the following. 1) There were significant differences in mean BP and prevalence rates of hypertension, with both being higher in the Kazak and Tibetan subjects than in Han and Uygur subjects. 2) The highest mean body mass index (BMI) was observed in the Kazak subjects, while the highest 24-h urinary sodium (Na) and sodium to potassium (Na/K) ratio excretion were observed in the Tibetan subjects. There were also significant differences in other factors, such as magnesium, 3-methylhistidine (3MH) (a biological marker of animal protein intake) and taurine (a biological marker of seafood intake) excretion levels among the four ethnic peoples. 3) In general, BMI, Na and/or Na/K ratios were positively, and 3MH/creatinine and taurine/creatinine ratios were negatively associated with BP. 4) After adjustment for age, sex and potassium, subjects with obesity (BMI > or =26 kg/m2) had significantly higher relative risk of being hypertensive (HT) than those with BMI<26 kg/m2 in the Han, Uygur and Kazak populations; and subjects with elevated sodium excretion (Na > or =244 mmol/day) had significantly higher relative risk of being HT than those with Na<244 mmol/day in the Han, Uygur and Tibetan populations. In conclusion, mean BP and prevalence rates of hypertension were significantly different among the four ethnic groups. These differences are likely to be due, at least in part, to the differences in several diet-related factors, which in turn are associated with culture and environmental differences. Different health promotion strategies might thus be emphasized in different populations.

[Coronary risk appraisal for primary prevention of coronary heart disease in a community].

PURPOSE: In discussion on application of "National Health Promotion Toward 21st Century in Japan" in Kanagawa prefecture, it was noted that the age-adjusted mortality rate of death from ischemic heart disease in this part of Japan was higher than that for the whole nation in 1996. To facilitate development of a strategy for primary prevention of coronary heart disease (CHD), the present study was conducted to predict 2-yr incidence of CHD and decrease with simulations assuming improvement in CHD risk factors. METHODS: Using CHD risk prediction algorithm; the Weibull accelerated failure regression model based on the Framingham Heart Study, a 2-yr incidence of CHD was predicted for 1652 residents (515 male, 1137 female) on the basis of results of a health check up in 1998. We then estimated the probable decrease in CHD recalculated assuming decrease in total cholesterol (TC), increase in HDL-cholesterol (HDL-C), decrease in systolic blood pressure (SBP), or quitting the smoking habit. RESULTS: 1. The 2-yr probability of developing CHD for men free of heart disease was 2.79 +/- 2.17%, and that for men who had heart disease was 10.25 +/- 2.17%. The 2-yr probability for women free of heart disease was 16.80 +/- 14.40%, and that for women who had heart disease was 3.66 +/- 1.09%. As the reported probability of developing CHD in the U.S.A. is remarkably higher than in Japan, the fact that the present model was based on American data explains why these predicted probabilities are higher than values reported from Japanese cohort studies. 2. For men free of heart disease, a strategy for high risk case such as a decrease in TC and an increase in HDL-C, or quitting the smoking habit, was more effective than a population-based strategy. For women free of heart disease, the population-based strategy was more effective. 3. Women more than 60-yrs old who had a high 2-yr probability of developing CHD were divided into three groups; high, middle, and low risk. The mean body weight, mean body mass index, mean diastolic blood pressure, and mean blood glucose in the high risk group were significantly higher than the values in the other groups. Decrease in systolic blood pressure was a more effective strategy for decrease in CHD incidence in the high risk group than in the other groups. CONCLUSIONS: CHD risk prediction of this type may be considered useful for setting target CHD risk factors and for focusing interventions to prevent CHD effectively.

Base heart rate during sleep in hypertensive and normotensive subjects.

OBJECTIVE: Many studies have reported that the resting heart rate (HR) is intimately related to the prognosis of cardiovascular disease. However, HR in the waking state is influenced by psychological and physical activity and has low reproducibility. To measure the base HR (minimum and stable HR during sleep) with ease, we developed a wristwatch-type HR recorder. We then investigated the pathophysiological significance of the base HR. SUBJECTS AND METHODS: The subjects were 158 patients (82 men and 76 women) with essential hypertension (HT) on no medication and 204 normotensive (NT) subjects (105 men and 99 women, matched for age). On the basis of pulse waves from the wristwatch-type photoelectric plethysmograph, using a blue sensor with a wavelength of 450 nm, HR was recorded easily minute by minute during sleep time. In addition, 40 (23 men and 17 women) of the HT patients were hospitalized. Their cardiac index (CI) and stroke volume index (SVI) were measured by means of the cuvette method during waking time and night-time deep sleep when their HR had reached a minimum level. RESULTS: Mean base HR (HRo) in NT subjects was 49+/-4 beats per minute (bpm) and tended to rise with increasing age (r = 0.51, P < 0.01). In HT patients, HR0 was significantly higher: 60+/-7 bpm (P < 0.01). CI of HT patients, measured during night-time deep sleep, maintained a stable value of 2.45+/-0.36 l/min per m2. SVI in patients whose HR0 was above 60 was significantly lower than that in patients whose HR0 was below 60 (37+/-4.5: 45+/-4.8 ml/m2, P < 0.01). Corresponding differences in mean HR and SVI during waking or night-time, became smaller. CONCLUSIONS: These findings suggest that there is a close relation between base HR and cardiac function caused by such conditions as age and hypertension. This relation became indistinct during waking time. Moreover, the wristwatch-type HR recorder appears to be a useful tool for measuring base HR.

Fertilizability and developmental capacity of bovine oocytes cultured individually in a chemically defined maturation medium.

This study investigated effects of adding hypotaurine (HT), beta-merocaptoethanol (beta-ME), or both into a chemically defined maturation medium (TCM-199 containing 0.1% polyvinyl alcohol: PVA) on maturation, fertilization and development of individually (single) cultured bovine oocytes. Mean GSH concentration in the oocytes cultured in the medium supplemented with either beta-ME (1.11 +/- 0.05 nM) or HT plus beta-ME (0.97 +/- 0.03 nM) was significantly (P < 0.05) higher than that in the medium containing PVA alone (0.75 +/- 0.03 nM). Adding beta-ME showed a significantly (P < 0.05) higher rate of the second metaphase stage (93.6 +/- 3.3%) than in the medium containing PVA alone (single-control) (65.2 +/- 7.9%). Adding both HT and beta-ME showed significantly (P < 0.05) higher rates (92.6 +/- 2.7%) of normal fertilization than did adding HT alone (63.5 +/- 4.6%). Also, adding both HT and beta-ME significantly (P < 0.05) lowered the polyspermy rate than did adding HT alone. Adding either beta-ME or both HT and beta-ME showed no significant difference in cleavage. Blastocyst development did not improve significantly adding either HT, beta-ME or both, although beta-ME alone or HT plus beta-ME tended to result in a higher rate of blastocysts (6.4 and 6.8%, respectively) than resulted without additives (1.6%). Our results show that adding beta-ME to a chemically defined maturation medium increased the intracellular GSH level of bovine oocytes cultured individually, and can improve the maturation rate leading to the blastocyst stage throughout in vitro production.

Goblet cell carcinoid of the appendix: Investigation of the expression of beta-catenin and E-cadherin.

Goblet cell carcinoids are rare neoplasms that predominantly occur in the appendix. In this report we present a case of goblet cell carcinoid of the appendix. A 58-year-old male patient complaining of pain in the right lower quadrant was diagnosed with acute appendicitis and underwent an appendectomy. Histological examination of the resected appendix revealed goblet cell carcinoid. Infiltration of tumor cells beyond the appendix was observed and the surgically resected margin was positive for tumor cells. Carcinoembryonic antigen (CEA) was diffusely detected by immunohistochemistry, and cytokeratin 20, neuron-specific enolase (NSE), chromogranin A and serotonin were focally observed in the tumor cells. The expression of beta-catenin and E-cadherin was investigated to compare with that of typical rectal carcinoids (n = 3) and colon adenocarcinomas (n = 3). In normal colonic and rectal mucosae, beta-catenin and E-cadherin stained positive on the plasma membrane. In the case reported here, beta-catenin showed a preserved expression on the plasma membrane of goblet cell carcinoid; a pattern similar to typical carcinoids rather than to adenocarcinomas. However, E-cadherin demonstrated a reduced expression on the plasma membrane of the tumor cells. This staining pattern was identical to those both of carcinoids and of adenocarcinomas. These findings suggest the possibility that, in some cases, the adherens junctions of goblet cell carcinoids are similar to those of typical carcinoids rather than to those of adenocarcinomas.

Different associations of blood pressure with 24-hour urinary sodium excretion among pre- and post-menopausal women. WHO Cardiovascular Diseases and Alimentary Comparison (WHO-CARDIAC) Study.

OBJECTIVE: Having found no definite relationship between blood pressure (BP) and 24h sodium excretion in women aged 48-56 years (in contrast to the results in men of the same age) in the WHO Cardiovascular Diseases and Alimentary Comparison (WHO-CARDIAC) Study, we analyzed the data to investigate whether the sodium-BP association differed between pre- and post-menopausal women. DESIGN AND METHODS: The WHO-CARDIAC is a multicenter cross-sectional study, involving, as of July 2000, 60 collaborating centers in 25 countries. In each center, 100 men and 100 women aged 48-56 years were selected randomly from the general population of the area. In this report, 2,212 women in 21 centers located in 17 countries worldwide, who had data on menopausal status, were studied. RESULTS: After adjustment for age, body mass index (BMI) and 24h urinary potassium excretion, 24h sodium excretion was positively and significantly associated with systolic blood pressure (SBP) [pooled regression coefficient: 0.037 (SE 0.01), P < 0.01] and with diastolic blood pressure (DBP) [0.023 (0.006), P< 0.01] in post-menopausal women. Pooled regression coefficients of sodium-BP association were not significant in pre-menopausal women (P< 0.05). Cross-center correlation analyses of the 21 centers showed that 24h sodium excretion was positively associated with SBP and DBP in both pre- and post-menopausal women, and this positive association between sodium excretion and SBP was significant in post-menopausal women (R2 = 0.23, P = 0.029). CONCLUSION: Different associations between sodium and BP were observed in women with pre- and post-menopausal status. There may be a tendency for salt sensitivity to increase at the menopause.

[Utilization of emergency ambulances in Yokohoma City, Japan].

OBJECTIVE: In recent years, the annual number of emergency ambulance (EA) calls has increased in Yokohama city, Japan. A questionnaire study was carried out to describe behavioral features of the users in Yokohama city, and to investigate their relationship with the increase in EA utilization. METHODS: We randomly recruited 2,910 citizens, aged 15 years or older, for the questionnaire study and a total of 2,294 (78.8%) replied. The questionnaire included questions about their demographic characteristics, history of EA use, existence of family doctors, and knowledge of emergency medical services and emergency medical information centers. Additionally, respondents who had used EA previously were asked about their reasons for this. RESULTS: A total of 513 (22.4%) respondents answered that they had used EA previously. A slightly higher rate of EA use was shown among elderly people, 65 years old or over (a rate of 26.2%). The major reason for requesting EA use was the urgency of the disease or the injury (61.8%). 182 respondents answered that they requested EA as a means of transportation. However, most of them also mentioned that the urgency of the disease or the injury was one of the reasons for their request. This survey showed no evidence that the citizens of Yokohama have used EA improperly. Elderly people, among whom the annual number of EA uses has increased rapidly over the years, tended to employ EA in a way more in line with regulations than other generations. CONCLUSION: This study suggested that the basic reason for the increase of EA utilization in Yokohama city was not due to inappropriate demand but to the aging of the population.

Association of essential hypertension in elderly Japanese with I/D polymorphism of the angiotensin-converting enzyme (ACE) gene.

Recent evidence suggests that an insertion/deletion (I/D) polymorphism of the gene encoding angiotensin-converting enzyme (ACE) is associated with myocardial infarction and related cardiovascular diseases. We investigated a possible association of the ACE polymorphism with essential hypertension in a total of 263 cases/controls from among the elderly (age, over 70 years) and middle-aged (age between 30 and 60 years) Japanese population. The frequency of the I/I homozygote was significantly higher in hypertensive subjects than in controls in the elderly age group (33/57 vs 16/46; P = 0.02), but no association was observed in the middle-aged group (25/75 vs 26/85; P = 0.71). Similarly, having at least one insertion allele was associated with essential hypertension in the elderly age group (83/114 vs 46/92 in controls; P = 0.001), but not in the middle-aged group (78/150 vs 94/170; P = 0.524). These data suggest that genetic variation at the ACE locus may be associated with some determinants for blood pressure in elderly persons, and imply the involvement of the ACE insertion/deletion polymorphism in the etiology of age-related essential hypertension in the Japanese population.

Comparative studies of diet-related factors and blood pressure among Chinese and Japanese: results from the China-Japan Cooperative Research of the WHO-CARDIAC Study. Cardiovascular Disease and Alimentary Comparison.

We aimed to compare the differences in diet-related factors and their associations with blood pressure (BP) between Chinese and Japanese. A total of 1,151 Chinese (M/F: 551/600) and 1,681 Japanese (782/899), aged 48-56 years, were studied using a multi-center cross-sectional study design. This work was a constituent part of the World Health Organization (WHO) Cardiovascular Disease and Alimentary Comparison (CARDIAC) Study. Measurements included in the present report were BP, body mass index (BMI), serum total cholesterol (TC), 24-h urinary sodium, potassium, calcium, magnesium, creatinine, 3-Methylhistidine (3MH, a marker of animal protein intake) and taurine (a marker of seafood intake) excretion levels. Results were as follows: (a) Japanese men had a significantly higher prevalence of hypertension than the Chinese (34.4% vs. 20.5%, p<0.01). After adjustment for age, Japanese men had a significantly higher mean systolic and diastolic BP (SBP, DBP), and Japanese women had a significantly higher DBP than the Chinese subjects overall (p<0.01, respectively). (b) Japanese had significantly higher mean BMI, TC and sodium excretion, and lower mean magnesium excretion than Chinese (p<0.01). (c) In the Japanese sample, multiple linear regression analyses (using a stepwise procedure) showed that SBP had a significant positive association with BMI and sodium excretion, and a significant negative association with magnesium excretion, while DBP had a significant positive association with BMI and a significant negative association with the 3MH to creatinine ratio (3MH/Cre). In the Chinese sample, both SBP and DBP showed a significant positive association with BMI and sodium, and a significant negative association with 3MH/Cre. In conclusion, Japanese had significantly higher mean BP than Chinese. The differences in BP may have been partly attributable to differences in various diet-related factors, particularly in BMI, sodium, magnesium-rich foods and animal protein intake, between the two populations.

Fertilizability and developmental capacity of individually cultured bovine oocytes.

Culture of single oocytes throughout in vitro maturation (IVM), fertilization (IVF) and culture (IVC) provides detailed information on maturity, fertilizability and developmental capacity of individual bovine oocytes and embryos. In the present study, effects of sperm concentration (Experiment 1), microdrop size (Experiment 2), and the addition of hypotaurine (HT) or glutathione (GSH; Experiment 3) during IVF were investigated. In Experiment 4, in vitro maturity and developmental capacity of bovine oocytes cultured for IVM in a medium supplemented with fetal calf serum (FCS), bovine serum albumin (BSA) or polyvinyl alcohol (PVA) during IVM were investigated. In Experiments 1 to 3, the percentages of normal (2 pronuclei with a spermtail) and polyspermic fertilization in singly cultured oocytes were similar to those of group IVF culture (5 oocytes/drop). The addition of GSH during single oocyte IVF significantly increased the proportion of normal fertilization and decreased the polyspermic fertilization compared with addition of HT or of the control. The rates of mature oocytes (62.4 and 67.7%) and blastocyst development (12.9 and 15.2%) for single oocyte IVM cultures (Experiment 4) were also similar compared with the group culture; PVA supplementation significantly increased the matured oocyte rate, but decreased blastocyst development significantly (7.1%) as compared with FCS (19.5%) or BSA (15.6%). These results indicate that a single oocyte culture system throughout in vitro production of bovine embryos provides similar maturity, fertilizability and developmental capacity to oocytes cultured in groups.

Behavioural and serological human immunodeficiency virus risk factors among female commercial sex workers in Cambodia.

BACKGROUND: The spread of human immunodeficiency virus (HIV) in Cambodia is mainly caused by sexual transmission and the high-risk group in this country are female commercial sex workers (CSW). There are two types of CSW, direct CSW (DCSW) and indirect CSW (IDCSW), who are different from each other in sexual activities. This study was conducted in order to describe the risk factors on HIV for each type of CSW, and to establish effective preventive strategies against the HIV epidemic among CSW. METHODS: The participants, 143 DCSW and 94 IDCSW, were interviewed using a questionnaire to determine their demographic characteristics and behaviour. Blood samples were taken for serological tests on HIV, Chlamydia trachomatis and syphilis. The association between their behavioural pattern and their serological results was analysed. RESULTS: The questionnaire study showed that IDCSW had a riskier behavioural pattern than DCSW. The HIV seroprevalence rates of the DCSW and the IDCSW were 52.4% and 22.3%, respectively. Univariate logistic analyses showed a significant association between HIV antibody (HIV-Ab) and current age, age at commencement of commercial sex work, duration of commercial sex work, and the seropositivity of Chlamydia trachomatis-IgG antibody (CT-IgG-Ab) among the DCSW. The analyses also showed a significant relationship between HIV-Ab and CT-IgG-Ab among the IDCSW. CONCLUSIONS: Improving condom use rate is very important in order to prevent an HIV epidemic among the two types of CSW. This study also suggests it is important to prevent sexually transmitted disease (STD) such as Chlamydia trachomatis infection. The STD control programme could be efficient for HIV prevention, especially among DCSW.

Cross-sectional study on risk factors of HIV among female commercial sex workers in Cambodia.

To describe epidemiological features on HIV prevalence among female commercial sex workers (CSWs), a cross-sectional study on sexual behaviour and serological prevalence was carried out in Cambodia. The CSWs were interviewed on their demographic characters and behaviour and their blood samples were taken for testing on sexually transmitted diseases, including HIV, Chlamydia trachomatis, syphilis, and hepatitis B. Associations between risk factors and HIV seropositivity were analysed. High seroprevalence of HIV and Chlamydia trachomatis IgG antibody (CT-IgG-Ab) was shown among the CSWs (54 and 81.7%, respectively). Univariate logistic regression analyses showed an association between HIV seropositivity and age, duration of prostitution, the number of clients per day and CT-IgG-Ab. Especially, high-titre chlamydial seropositivity showed a strong significant association with HIV prevalence. In multiple logistic regression analyses, CT-IgG-Ab with higher titre was significantly independently related to HIV infection. These suggest that existence of Chlamydia trachomatis is highly related to HIV prevalence.