Milk intake and incident stroke and CHD in populations of European descent: a Mendelian randomisation study.

Higher milk intake has been associated with a lower stroke risk, but not with risk of CHD. Residual confounding or reverse causation cannot be excluded. Therefore, we estimated the causal association of milk consumption with stroke and CHD risk through instrumental variable (IV) and gene-outcome analyses. IV analysis included 29 328 participants (4611 stroke; 9828 CHD) of the European Prospective Investigation into Cancer and Nutrition (EPIC)-CVD (eight European countries) and European Prospective Investigation into Cancer and Nutrition-Netherlands (EPIC-NL) case-cohort studies. rs4988235, a lactase persistence (LP) SNP which enables digestion of lactose in adulthood was used as genetic instrument. Intake of milk was first regressed on rs4988235 in a linear regression model. Next, associations of genetically predicted milk consumption with stroke and CHD were estimated using Prentice-weighted Cox regression. Gene-outcome analysis included 777 024 participants (50 804 cases) from MEGASTROKE (including EPIC-CVD), UK Biobank and EPIC-NL for stroke, and 483 966 participants (61 612 cases) from CARDIoGRAM, UK Biobank, EPIC-CVD and EPIC-NL for CHD. In IV analyses, each additional LP allele was associated with a higher intake of milk in EPIC-CVD (ß = 13·7 g/d; 95 % CI 8·4, 19·1) and EPIC-NL (36·8 g/d; 95 % CI 20·0, 53·5). Genetically predicted milk intake was not associated with stroke (HR per 25 g/d 1·05; 95 % CI 0·94, 1·16) or CHD (1·02; 95 % CI 0·96, 1·08). In gene-outcome analyses, there was no association of rs4988235 with risk of stroke (OR 1·02; 95 % CI 0·99, 1·05) or CHD (OR 0·99; 95 % CI 0·95, 1·03). Current Mendelian randomisation analysis does not provide evidence for a causal inverse relationship between milk consumption and stroke or CHD risk.

Association of leukocyte DNA methylation changes with dietary folate and alcohol intake in the EPIC study.

BACKGROUND: There is increasing evidence that folate, an important component of one-carbon metabolism, modulates the epigenome. Alcohol, which can disrupt folate absorption, is also known to affect the epigenome. We investigated the association of dietary folate and alcohol intake on leukocyte DNA methylation levels in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. Leukocyte genome-wide DNA methylation profiles on approximately 450,000 CpG sites were acquired with Illumina HumanMethylation 450K BeadChip measured among 450 women control participants of a case-control study on breast cancer nested within the EPIC cohort. After data preprocessing using surrogate variable analysis to reduce systematic variation, associations of DNA methylation with dietary folate and alcohol intake, assessed with dietary questionnaires, were investigated using CpG site-specific linear models. Specific regions of the methylome were explored using differentially methylated region (DMR) analysis and fused lasso (FL) regressions. The DMR analysis combined results from the feature-specific analysis for a specific chromosome and using distances between features as weights whereas FL regression combined two penalties to encourage sparsity of single features and the difference between two consecutive features. RESULTS: After correction for multiple testing, intake of dietary folate was not associated with methylation level at any DNA methylation site, while weak associations were observed between alcohol intake and methylation level at CpG sites cg03199996 and cg07382687, with qval = 0.029 and qval = 0.048, respectively. Interestingly, the DMR analysis revealed a total of 24 and 90 regions associated with dietary folate and alcohol, respectively. For alcohol intake, 6 of the 15 most significant DMRs were identified through FL. CONCLUSIONS: Alcohol intake was associated with methylation levels at two CpG sites. Evidence from DMR and FL analyses indicated that dietary folate and alcohol intake may be associated with genomic regions with tumor suppressor activity such as the GSDMD and HOXA5 genes. These results were in line with the hypothesis that epigenetic mechanisms play a role in the association between folate and alcohol, although further studies are warranted to clarify the importance of these mechanisms in cancer.

The first pilot study of expanded newborn screening for inborn errors of metabolism and survey of related knowledge and opinions of health care professionals in Hong Kong.

INTRODUCTION: Newborn screening is important for early diagnosis and effective treatment of inborn errors of metabolism (IEM). In response to a 2008 coroners' report of a 14-year-old boy who died of an undiagnosed IEM, the OPathPaed service model was proposed. In the present study, we investigated the feasibility of the OPathPaed model for delivering expanded newborn screening in Hong Kong. In addition, health care professionals were surveyed on their knowledge and opinions of newborn screening for IEM. METHODS: The present prospective study involving three regional hospitals was conducted in phases, from 1 October 2012 to 31 August 2014. The 10 steps of the OPathPaed model were evaluated: parental education, consent, sampling, sample dispatch, dried blood spot preparation and testing, reporting, recall and counselling, confirmation test, treatment and monitoring, and cost-benefit analysis. A fully automated online extraction system for dried blood spot analysis was also evaluated. A questionnaire was distributed to 430 health care professionals by convenience sampling. RESULTS: In total, 2440 neonates were recruited for newborn screening; no true-positive cases were found. Completed questionnaires were received from 210 respondents. Health care professionals supported implementation of an expanded newborn screening for IEM. In addition, there is a substantial need of more education for health care professionals. The majority of respondents supported implementing the expanded newborn screening for IEM immediately or within 3 years. CONCLUSION: The feasibility of OPathPaed model has been confirmed. It is significant and timely that when this pilot study was completed, a government-led initiative to study the feasibility of newborn screening for IEM in the public health care system on a larger scale was announced in the Hong Kong Special Administrative Region Chief Executive Policy Address of 2015.

Managing aging men in Asia: a strategic approach.

We have established a comprehensive diagnostic paradigm for the management of aging men which seeks to evaluate the various determinants of the aging process in five major health areas: cardio-health, bone health, sex health, general health and endocrine state. This paradigm appears to be useful for the management of the problem of aging in our local population. It could be used for the management of individuals as well as for population research. When combined with the establishment of evidence-based management modalities, it will provide a useful tool for the holistic management of aging in Asia.

Effects of 4-hydroxyandrostenedione and hyperstimulation with pregnant mare serum gonadotrophin on early embryonic development in rats.

A possible role of high oestradiol levels in mediating the adverse effects of hyperstimulation with pregnant mare serum gonadotrophin (PMSG) on early embryonic development in the rat was investigated using an aromatase inhibitor, 4-hydroxyandrostenedione (4-OHA), to inhibit endogenous oestradiol production. Three experiments were conducted in this study. In the first, varying doses of 4-OHA were administered either concurrently with human chorionic gonadotropin (hCG) to pro-oestrus female rats hyperstimulated at early di-oestrus stage with 20 IU PMSG or alone into nonhyperstimulated pro-oestrus females. At high doses of 1000, 2000, or 5000 microg/rat, 4-OHA substantially improved the survival of embryos in hyperstimulated females, while low doses of 100 and 500 microg/rat were ineffective. The protective effect of 4-OHA on embryo count was optimum at 2000 microg. When administered alone, only the highest dose of 5000 microg/rat 4-OHA increased embryo count. In the second experiment, higher doses of PMSG were studied (30 or 40 IU), with or without 5000 microg/rat 4-OHA given at the time of hCG injection. PMSG proved to be more detrimental with increasing dose, and 5000 microg/rat 4-OHA was able to rescue embryos from death in the 30, but not 40, PMSG group. In the third experiment, the influence of the timing of 4-OHA treatment on its ability to improve the embryo count in hyperstimulated females was examined by introducing 4-OHA 24 h earlier, rather than at the time of hCG treatment. The results showed the importance of timing of 4-OHA administration, as 5000 microg/rat 4-OHA was able to restore embryo survival in the 40 PMSG hyperstimulated group only when it was administered 24 h before hCG injection. Together, these results highlighted that 4-OHA, when administered at the appropriate time and dose, could reverse the negative effects of hyperstimulation from PMSG on early embryonic development. This may be due to its potent aromatase inhibiting properties that lead to the suppression of oestrogen production, thereby alleviating the supraphysiological level of oestradiol, which is typically present in PMSG-treated females. Interestingly, 4-OHA treatment on its own was able to positively influence embryo count when given at a high dose of 5000 microg/rat, and this may be associated with its weak androgenic properties. In conclusion, this study supports the hypothesis that excessive oestradiol is responsible for the negative effects of hyperstimulation with PMSG on early embryonic development.

The rotary pursuit test is not an index of normal psychomotor function in humans.

OBJECTIVE: This study sought to assess whether the rotary pursuit test is a good indication of the psychomotor performance of human subjects during normal working hours. Circadian hormonal profiles of salivary melatonin and cortisol were also established for correlation with performance. METHODS: Ten healthy individuals working in the Department of Obstetrics and Gynecology laboratory participated in this study. The experiment was conducted during a normal 8.5-hour working day in which routine laboratory tasks such as running radioimmunoassays were performed. Saliva samples were collected every 2 hours starting at 8:00 a.m. Simultaneously, self-rated questionnaires on mood states, sleepiness, stress, and types of food and drinks consumed were also recorded. At 10:00 a.m., 12:00 noon, 2:00 p.m., and 4:00 p.m., the subjects' were tested on the rotary pursuit machine, on which their ability to track a rotating target with a stylus was tested by means of measuring the time the stylus stays on target. RESULTS: The circadian profiles of salivary melatonin and cortisol were similar to what previous studies have shown. Increases in cortisol levels were associated with food intake, work stress, or spontaneous awakening. Tracking performance (time on target) improved significantly from 10:00 a.m. to 2:00 p.m. and then decreased nonsignificantly at 4:00 p.m. only at the speed setting of 60 rpm. There was no correlation between the three parameters measured. SUMMARY: Variation of psychomotor performance during a normal working day and in noncircadian disrupted individuals cannot be measured by the rotary pursuit test. Furthermore, a learning effect could mask any variation in performance.

Effects of one night of sleep deprivation on hormone profiles and performance efficiency.

This study examined the effects of one night of sleep deprivation on melatonin and cortisol profiles, as well as performance efficiency of military service members. Sleep intervention consisted of total lack of sleep (N = 7) or 8 hours of sleep (control group; N = 7) during the night. All parameters were measured at selected time intervals before (day 1), during (only in sleep-deprived individuals), and after (day 2) sleep intervention. Rotary pursuit scores and handgrip strength data were used as indices of psychomotor and physical performance, respectively. In sleep-deprived individuals, more salivary melatonin, but not cortisol, was secreted than in subjects who slept adequately. Significant increases in melatonin and cortisol were noted, especially at 1:30 p.m. on the day after nighttime sleep deprivation. In contrast, the tracking scores for rotary pursuit and grip strength among sleep-deprived and rested individuals were comparable. Across a normal working day (day 1), all parameters studied revealed time-specific fluctuations in both control and sleep-deprived groups. Irrespective of nighttime sleep schedule, the patterns of performance on day 2 differed from those on day 1. The tracking performance improved on day 2, whereas grip strength worsened, which may reflect inherent learning and muscle fatigue, respectively. During the night of sleep deprivation, performance declined. In conclusion, the present study showed that one night of sleep deprivation (8 hours) resulted in significant hormonal changes on the next afternoon but did not modify tracking and muscular strength performance.

Direct effects of varying doses of oestradiol on early embryonic development in in vitro culture of rat's two-cell embryos.

Hyperstimulation in the rat using pregnant mares' serum gonadotrophin (PMSG) has been known to cause death in pre-implantation embryos, as well as enhancement of oestradiol production. This study examines the effect of oestradiol, in levels that are found in hyperstimulated pregnant rats, on pre-implantation embryonic development. Using a simplified in vitro system, 2-cell embryos retrieved from rats on the 2nd day of pregnancy were cultured in rat two-cell embryo culture medium (R2ECM) containing pharmacological doses of oestradiol for 96 h and scored daily in the morning. Three ngxmL(-1) oestradiol reduced the incidence of >8-cell embryos to morulae on the 5th day and blastocysts on the 6th day of development. Most embryos were retarded at the lower cell stages on the 5th day and degenerated by the 6th day. None of the blastocysts expanded on the last day of culture. Fifteen ngxmL(-1) oestradiol accelerated embryo development on the 3rd day but retarded development on the 4th day, and increased the incidence of degenerated embryos by the 5th and 6th day of development. These results suggest that the elevated oestradiol may constitute a mechanism by which PMSG induces death in pre-implantation rat embryos, possibly via a direct action on the embryos.

Sleep/wake cycle and circadian disturbances in shift work: strategies for their management--a review.

INTRODUCTION: There has been a growing concern about the ability of individuals to maintain adequate levels of performance over long work shifts, particularly when those shifts span night-time hours. It has, therefore, become expeditious to understand and apply principles of circadian rhythms in order to establish simple, rational and appropriate strategies to help our shift workers maximise their performance and minimise their health problems under the various shift work regimes. This review sought to outline several principles of circadian rhythms and the sleep/wake cycle and some possible strategies to manage disturbances in the sleep and performance arising from shift works. METHODS: Many studies in this field had been carried out. The present review concerns studies which elucidate the general circadian principles as well as those which may provide helpful information applicable for us in the work environment we are living in. RESULTS: It has been found that shift workers invariably suffer from a constellation of symptoms, which can sometime severely compromise their ability to perform optimally during their shift work. There are many factors that influence the sleep/wake cycle and thus, the performance of shift work. These include 1) circadian factors, 2) type of shift work, 3) how a person adapt to circadian disruption, 4) ageing, 5) sleep factors and 6) social and domestic factors. CONCLUSIONS: Several possible strategies could be adopted to improve sleep and performance. These include 1) appropriate scheduling of shift work, 2) proper consideration of the speed of shift rotation, 3) strategies for sleep and napping, 4) installing appropriate lighting at the workplace, 5) the use of sleeping pills/hypnotics such as melatonin and melatonin agonists.

Circadian disturbances after night-shift work onboard a naval ship.

The aim of the present study was to investigate how night duties can affect the circadian rhythms of military personnel working onboard a naval ship. Twenty individuals on a regular day-work schedule from 9:00 a.m. to 6:00 p.m. (serving as controls) and 40 individuals on night-shift duties participated in the study. Salivary melatonin and cortisol profiles were established within two 24-hour periods from 2-hour saliva samplings. Under the condition of abrupt shift in work/rest schedule, the majority of the navy officers (52%) retained their normal melatonin profiles. Twelve percent displayed a right phase shift in melatonin rhythm after night work. Nineteen percent exhibited distortions in the form of abnormal peaks or troughs, and 17% showed signs of disrupted rhythm in the form of low daytime levels of melatonin throughout the sampling period. No consistent relationship was found between the melatonin changes and various work stations of the ship. Prominent changes in the cortisol profile included unexpected peaks or troughs that may be related to the conditions that individuals were exposed to, i.e., high noise level in the engine room, as well as to performing intense tracking operations. The findings of this study (1) show the possible detrimental effects of shift duties on circadian rhythms, (2) highlight a wide interindividual variation in the manner in which the circadian systems respond to an abrupt phase shift in work/rest schedules, and (3) form the basis for further investigations into effective strategies to help military personnel cope with shift work, thereby maintaining health and high working standards while on duty.

Successful in vitro growth of rat two-cell embryos to blastocysts using a simple chemically defined medium.

The aim of the present study was to formulate a simple chemically defined medium for the in vitro growth of rat two-cell embryos to blastocysts. Embryos from day 2 pregnant rats were retrieved and placed in paraffin oil-covered droplets of "rat two-cell embryo culture medium" (R2ECM) containing combinations of various serum supplements, glucose, L-glutamine, and cultured up to 96 h in a CO(2) incubator. Embryos cultured in the basic medium (R2ECM), as well as those supplemented either with fetal bovine serum (FBS) or male rat serum (MRS) did not develop beyond the two- to four-cell stage. In R2ECM with 0.3% bovine serum albumin (BSA) and 7.5 mM glucose, 44% of embryos reached the blastocyst stage by 96 h in culture, and the blastulation rate increased to about 83% when 1 mM of L-glutamine was added. To evaluate the effects of varying doses of glucose, two-cell embryos were cultured in R2ECM supplemented with 0.3% BSA, 1 mM L-glutamine, and 2.5, 5.0, or 7.5 mM of glucose. The percentage of embryos reaching the blastocyst stage for 2.5, 5.0, and 7.5 mM glucose was 64.6%, 65.3%, and 82.9%, respectively. The present study showed that the modified medium (R2ECM) is a simple chemically defined medium that is capable of supporting in vitro growth of rat two-cell embryos to blastocysts in high proportion (greater than 80%) without the need for change of medium within 96 h of culture.

Toxic effects of chromic sulphate on the common carp, Cyprinus carpio.

The effects of chromic sulphate, which is commonly used in the tanning of leather, on the common carp, Cyprinus carpio and the bighead, Aristichthys nobilis, were studied. C. carpio was found to be more susceptible than A. nobilis to chromic sulphate at the lowest concentration tested (100 mg/l) whereas results obtained at other concentration were similar for both species. Damage to the gills, liver and intestine was observed by histopathological examination. A wide range of chemicals is used in the different stages of treating leather and a possible treatment of the effluent from the tanneries is suggested.