Glycogen synthase kinase-3 induces Alzheimer's disease-like phosphorylation of tau: generation of paired helical filament epitopes and neuronal localisation of the kinase

Glycogen synthase kinase-3 (GSK-3) reduced the mobility of human tau on SDS-PAGE, prevented binding of the monoclonal antibody (mAb), Tau.1, and induced binding of the mAb 8D8. Recombinant tau phosphorylated by GSK-3 aligned on SDS-PAGE with the abnormally phosphorylated tau (PHF-tau) associated with the paired helical filaments in Alzheimer's disease brain. Phosphorylated serine396 (numbering of the largest human brain tau isoform) was identified as a binding site on tau for mAb 8D8. The localisation of GSK-3 within granular structures in pyramidal cells indicates that GSK-3 alpha and GSK-3 beta may have a role in the production of PHF-tau in Alzheimer's disease.

Modulation of the glycogen synthase kinase-3 family by tyrosine phosphorylation

Glycogen synthase kinase-3 (GSK-3) is a protein serine kinase implicated in the cellular response to insulin. The enzyme is the mammalian homologue of the zeste-white3 (shaggy) homeotic gene of Drosophila melanogaster and has been implicated in the regulation of the c-Jun/AP-1 transcription factor. In mammals this protein serine kinase is encoded by two related genes termed GSK-3 alpha and beta. Here, we demonstrate that these two proteins and the fruit fly protein are phosphorylated on tyrosine in vivo. Moreover, GSK-3 beta activity and function are shown to be dependent on tyrosine phosphorylation. The modified tyrosine residue is conserved in all members of the GSK-3 family and is equivalent to that required for activity by mitogen-activated protein (MAP) kinases. However, unlike MAP kinases, GSK-3 is highly phosphorylated on tyrosine and thus active in resting cells.

The hidden mortality of monochorionic twin pregnancies

In an ultrasound screening study at 10 to 14 weeks of gestation for measurement of fetal nuchal translucency thickness there were 102 monochorionic and 365 dichorionic twin pregnancies. In the monochorionic compared with the dichorionic pregnancies there was a higher rate of fetal loss before 24 weeks of gestation (12.2% versus 1.8%), perinatal mortality (2.8% versus 1.6%), prevalence of delivery before 32 weeks (9.2% versus 5.5%), and prevalence of birthweight below the 5th centile in both twins (7.5% versus 1.7%). However, the proportion of pregnancies with a birthweight discordancy of more than 25% was similar in the two groups (11.3% versus 12.1%).

Experience in monitoring gentamicin therapy during treatment of serious gram-negative sepsis

This paper reports our experience in monitoring gentamicin therapy during the treatment of 68 episodes of serious Gram-negative sepsis in 65 hospital patients. Most of the patients had major underlying disease. Of those who were adequately treated (peak serum concentrations of 5 mug/ml or more in 72 hours for septicaemia, urinary tract infection, and wound infection; and 8 mug/ml or more at some time during the course of treatment for pneumonia) 84% (46 out of 55) were cured. These serum concentrations could be achieved only by starting with a regimen of 5 mg/kg/day in three divided doses in all adult patients, subsequent dosage being determined by the results of rapid serum assay. The incidence of nephrotoxicity and symptomatic ototoxicity was no greater than in previous series. The main reason for assaying serum gentamicin is to ensure that an adequate dosage is achieved as soon as possible. In patients with impaired renal function or receiving prolonged high dosage assays also serve to guard against an excessive accumulation of gentamicin and an increased risk of toxicity.

The lambda sign at 10-14 weeks of gestation as a predictor of chorionicity in twin pregnancies

Chorionicity was prospectively determined in 369 twin pregnancies by ultrasound at 10-14 weeks of gestation. Pregnancies were classified as monochorionic if there was a single placental mass in the absence of the lambda sign at the inter-twin membrane-placental junction, and dichorionic if there was a single placental mass but the lambda sign was present, or the placentas were not adjacent to each other. In 81 (22%) cases, the pregnancies were classified as monochorionic and in 288 (78%) as dichorionic. Pregnancy outcome was available in 279 cases and all 63 of these pregnancies classified as monochorionic resulted in the delivery of same-sex twins. Similarly, all 100 different-sex pairs were correctly classified as dichorionic. These findings demonstrate the high reliability of ultrasound examination at 10-14 weeks of gestation in determining chorionicity in twin pregnancies.

Measuring mortality and the burden of adult disease associated with adverse childhood experiences in England: a national survey

BACKGROUND

ACE (adverse childhood experience) studies typically examine the links between childhood stressors and adult health harming behaviours. Using an enhanced ACE survey methodology, we examine impacts of ACEs on non-communicable diseases and incorporate a proxy measure of premature mortality in England.

METHODS

A nationally representative survey was undertaken (n = 3885, aged 18-69, April-July 2013). Socio-demographically controlled proportional hazards analyses examined the associations between the number of ACE categories (<18 years; e.g. child abuse and family dysfunction such as domestic violence) and cancer, diabetes, stroke, respiratory, liver/digestive and cardiovascular disease. Sibling (n = 6983) mortality was similarly analysed as a measure of premature mortality.

RESULTS

Of the total, 46.4% of respondents reported ≥1 and 8.3% ≥4 ACEs. Disease development was strongly associated with increased ACEs (e.g. hazard ratios, HR, 0 versus ≥4 ACEs; cancer, 2.38 (1.48-3.83); diabetes, 2.99 (1.90-4.72); stroke, 5.79 (2.43-13.80, all P < 0.001). Individuals with ≥4 ACEs (versus no ACEs) had a 2.76 times higher rate of developing any disease before age 70 years. Adjusted HR for mortality was strongly linked to ACEs (≥4 versus 0 ACEs; HR, 1.97 (1.39-2.79), P < 0.001).

CONCLUSIONS

Radically different life-course trajectories are associated with exposure to increased ACEs. Interventions to prevent ACEs are available but rarely implemented at scale. Treating the resulting health costs across the life course is unsustainable.

Screening for trisomy 21 in twin pregnancies by maternal age and fetal nuchal translucency thickness at 10-14 weeks of gestation

OBJECTIVE

To determine the prevalence of increased fetal nuchal translucency thickness in twin pregnancies and to evaluate screening for trisomy 21 by a combination of translucency thickness and maternal age.

DESIGN

Prospective screening study at 10 to 14 weeks of gestation.

SETTING

Fetal Medicine Centre.

POPULATION

22,518 self-selected pregnant women at 10 to 14 weeks of gestation, including 21,477 singleton and 448 twin pregnancies with live fetuses.

METHODS

Fetal nuchal translucency thickness was measured by ultrasound examination at 10-14 weeks. Sensitivity and false positive rates of screening for trisomy 21 by a combination of fetal nuchal translucency thickness and maternal age were calculated.

MAIN OUTCOME MEASURES

Prevalence of increased nuchal translucency thickness and detection of trisomy 21.

RESULTS

In the 448 twin pregnancies the nuchal translucency thickness was above the 95th centile of the normal range (for crown-rump length in singletons) in 65/896 fetuses (7.3%), including 7/8 (88%) with trisomy 21. Increased translucency was also present in four fetuses with other chromosomal abnormalities. In the chromosomally normal twin pregnancies the prevalence of increased nuchal translucency was higher in fetuses from monochorionic (8.4%; 16/190) than in those with dichorionic pregnancies (5.4%; 37/688). The minimum estimated risk for trisomy 21, based on maternal age and fetal nuchal translucency thickness, was 1 in 300 in 19.5% (175/896) of the twins including all eight of those with trisomy 21.

CONCLUSIONS

In twin pregnancies the sensitivity of fetal nuchal translucency thickness in screening for trisomy 21 is similar to that in singleton pregnancies, but the specificity is lower because translucency is also increased in chromosomally normal monochorionic twin pregnancies.

Surgery for colorectal cancer metastatic to the liver. Optimizing the results of treatment

Overall, hepatic resection appears to be an important means of curing patients with metastatic colorectal cancer isolated to the liver. The only absolute contraindication to surgery was the impossibility of a radical removal of tumor: if residual disease will remain after the hepatic resection, this operation is not indicated. A possible second contraindication to surgery is the presence of tumor in the hepatic or celiac lymph nodes. Such metastases from liver metastases signal a biologic grade of tumor that is almost sure to spread to other sites. However, one patient of the 25 in this group did survive long term when positive lymph node groups were dissected. Further clinical experience with this form of the disease along with trials of regional adjuvant therapies such as intraperitoneal chemotherapy may be needed. The presence of extrahepatic metastases at the time of liver resection should be considered a relative contraindication to this surgery, but if the patient can be made clinically disease free, long-term disease-free survival may result. It seems imperative that all patients with hepatic metastases be evaluated by an experienced hepatic surgeon for a curative resection. If the patient has between one and four metastases, a 25 per cent long-term disease-free survival rate can be expected. Patients who have a radical resection of more than four metastases should be considered to be in an experimental group in whom more data are needed. In our current state of knowledge, making such patients clinically disease free is their only chance for long-term survival. Other factors besides the number of metastases that will affect the prognosis of the patient include the disease-free interval between colorectal resection and liver resection, the pathologic margin of resection on the liver specimen, and the presence or absence of mesenteric lymph node metastases from the primary cancer. These factors should be considered when determining the prognosis in a given patient and should be used as stratification variables in prospective trials. However, from our analysis of available data, these factors should not be considered contraindications to hepatic resection.

Sex-specific relevance of diabetes to occlusive vascular and other mortality: a collaborative meta-analysis of individual data from 980 793 adults from 68 prospective studies

BACKGROUND

Several studies have shown that diabetes confers a higher relative risk of vascular mortality among women than among men, but whether this increased relative risk in women exists across age groups and within defined levels of other risk factors is uncertain. We aimed to determine whether differences in established risk factors, such as blood pressure, BMI, smoking, and cholesterol, explain the higher relative risks of vascular mortality among women than among men.

METHODS

In our meta-analysis, we obtained individual participant-level data from studies included in the Prospective Studies Collaboration and the Asia Pacific Cohort Studies Collaboration that had obtained baseline information on age, sex, diabetes, total cholesterol, blood pressure, tobacco use, height, and weight. Data on causes of death were obtained from medical death certificates. We used Cox regression models to assess the relevance of diabetes (any type) to occlusive vascular mortality (ischaemic heart disease, ischaemic stroke, or other atherosclerotic deaths) by age, sex, and other major vascular risk factors, and to assess whether the associations of blood pressure, total cholesterol, and body-mass index (BMI) to occlusive vascular mortality are modified by diabetes.

RESULTS

Individual participant-level data were analysed from 980 793 adults. During 9·8 million person-years of follow-up, among participants aged between 35 and 89 years, 19 686 (25·6%) of 76 965 deaths were attributed to occlusive vascular disease. After controlling for major vascular risk factors, diabetes roughly doubled occlusive vascular mortality risk among men (death rate ratio [RR] 2·10, 95% CI 1·97-2·24) and tripled risk among women (3·00, 2·71-3·33; χ2 test for heterogeneity p<0·0001). For both sexes combined, the occlusive vascular death RRs were higher in younger individuals (aged 35-59 years: 2·60, 2·30-2·94) than in older individuals (aged 70-89 years: 2·01, 1·85-2·19; p=0·0001 for trend across age groups), and, across age groups, the death RRs were higher among women than among men. Therefore, women aged 35-59 years had the highest death RR across all age and sex groups (5·55, 4·15-7·44). However, since underlying confounder-adjusted occlusive vascular mortality rates at any age were higher in men than in women, the adjusted absolute excess occlusive vascular mortality associated with diabetes was similar for men and women. At ages 35-59 years, the excess absolute risk was 0·05% (95% CI 0·03-0·07) per year in women compared with 0·08% (0·05-0·10) per year in men; the corresponding excess at ages 70-89 years was 1·08% (0·84-1·32) per year in women and 0·91% (0·77-1·05) per year in men. Total cholesterol, blood pressure, and BMI each showed continuous log-linear associations with occlusive vascular mortality that were similar among individuals with and without diabetes across both sexes.

INTERPRETATION

Independent of other major vascular risk factors, diabetes substantially increased vascular risk in both men and women. Lifestyle changes to reduce smoking and obesity and use of cost-effective drugs that target major vascular risks (eg, statins and antihypertensive drugs) are important in both men and women with diabetes, but might not reduce the relative excess risk of occlusive vascular disease in women with diabetes, which remains unexplained.

FUNDING

UK Medical Research Council, British Heart Foundation, Cancer Research UK, European Union BIOMED programme, and National Institute on Aging (US National Institutes of Health).

Evolution of foraging behavior in Drosophila by density-dependent selection

One of the rare examples of a single major gene underlying a naturally occurring behavioral polymorphism is the foraging locus of Drosophila melanogaster. Larvae with the rover allele, forR, have significantly longer foraging path lengths on a yeast paste than do those homozygous for the sitter allele, fors. These variants do not differ in general activity in the absence of food. The evolutionary significance of this polymorphism is not as yet understood. Here we examine the effect of high and low animal rearing densities on the larval foraging path-length phenotype and show that density-dependent natural selection produces changes in this trait. In three unrelated base populations the long path (rover) phenotype was selected for under high-density rearing conditions, whereas the short path (sitter) phenotype was selected for under low-density conditions. Genetic crosses suggested that these changes resulted from alterations in the frequency of the fors allele in the low-density-selected lines. Further experiments showed that density-dependent selection during the larval stage rather than the adult stage of development was sufficient to explain these results. Density-dependent mechanisms may be sufficient to maintain variation in rover and sitter behavior in laboratory populations.

Central obesity, insulin resistance, syndrome X, lipoprotein(a), and cardiovascular risk in Indians, Malays, and Chinese in Singapore

STUDY OBJECTIVE

To examine the hypothesis that the higher rates of coronary heart disease (CHD) in Indians (South Asians) compared with Malays and Chinese is at least partly explained by central obesity, insulin resistance, and syndrome X (including possible components).

DESIGN

Cross sectional study of the general population.

SETTING

Singapore.

PARTICIPANTS

Random sample of 961 men and women (Indians, Malays, and Chinese) aged 30 to 69 years.

MAIN RESULTS

Fasting serum insulin concentration was correlated directly and strongly with body mass index (BMI), waist-hip ratio (WHR), and abdominal diameter. The fasting insulin concentration was correlated inversely with HDL cholesterol and directly with the fasting triglyceride concentration, blood pressures, plasminogen activator inhibitor 1 (PAI-1), and tissue plasminogen activator (tPA), but it was not correlated with LDL cholesterol, apolipoproteins B and A1, lipoprotein(a), (Lp(a)), fibrinogen, factor VIIc, or prothrombin fragment (F)1 + 2. This indicates that the former but not the latter are part of syndrome X. While Malays had the highest BMI, Indians had a higher WHR (men 0.93 and women 0.84) than Malays (men 0.91 and women 0.82) and Chinese (men 0.91 and women 0.82). In addition, Indians had higher fasting insulin values and more glucose intolerance than Malays and Chinese. Indians had lower HDL cholesterol, and higher PAI-1, tPA, and Lp(a), but not higher LDL cholesterol, fasting triglyceride, blood pressures, fibrinogen, factor VIIc, or prothrombin F1 + 2.

CONCLUSIONS

Indians are more prone than Malays or Chinese to central obesity with insulin resistance and glucose intolerance and there are no apparent environmental reasons for this in Singapore. As a consequence, Indians develop some but not all of the features of syndrome X. They also have higher Lp(a) values. All this puts Indians at increased risk of atherosclerosis and thrombosis and must be at least part of the explanation for their higher rates of CHD.

Novel polymorphisms in the caprine PrP gene: a codon 142 mutation associated with scrapie incubation period

Age at disease onset and rate of progression of transmissible spongiform encephalopathies in man, sheep and mice are modulated by the host genome, in particular by the PrP gene and its allelic forms. Analysis of the caprine PrP gene revealed several different alleles. Four PrP protein variants were found, three of which were goat specific with single amino acid changes at codons 142, 143 and 240. The fourth was identical to the most common sheep PrP protein variant (Ala136-Arg154-Gln171). The dimorphism at codon 142 (Ile --> Met) appeared to be associated with differing disease incubation periods in goats experimentally infected with isolates of bovine spongiform encephalopathy, sheep scrapie CH1641 or sheep-passaged ME7 scrapie.

Cardiovascular diseases in Chinese, Malays, and Indians in Singapore. II. Differences in risk factor levels

STUDY OBJECTIVE

The aim of the study was to examine cardiovascular risk factors to see how these might explain differences in cardiovascular disease mortality among Chinese, Malays, and Indians in the Republic of Singapore.

DESIGN

The study was a population based cross sectional survey. Stratified systematic sampling of census districts, reticulated units, and houses was used. The proportions of Malay and Indian households were increased to improve statistical efficiency, since about 75% of the population is Chinese.

SETTING

Subjects were recruited from all parts of the Republic of Singapore.

SUBJECTS

2143 subjects aged 18 to 69 years were recruited (representing 60.3% of persons approached). There were no differences in response rate between the sexes and ethnic groups.

MEASUREMENTS AND MAIN RESULTS

Data on cardiovascular risk factors were collected by questionnaire. Measurements were made of blood pressure, serum cholesterol, low and high density lipoprotein cholesterol, fasting triglycerides and plasma glucose. In males the age adjusted cigarette smoking rate was higher in Malays (53.3%) than in Chinese (37.4%) or Indians (44.5%). In both sexes, Malays had higher age adjusted mean systolic blood pressure: males 124.6 mm Hg v 121.2 mm Hg (Chinese) and 121.2 mm Hg (Indians); females 122.8 mm Hg v 117.3 mm Hg (Chinese) and 118.4 mm Hg (Indians). Serum cholesterol, low density lipoprotein cholesterol and triglyceride showed no ethnic differences. Mean high density lipoprotein cholesterol in males (age adjusted) was lower in Indians (0.69 mmol/litre) than in Chinese (0.87 mmol/litre) and Malays (0.82 mmol/litre); in females the mean value of 0.95 mmol/litre in Indians was lower than in Chinese (1.05 mmol/litre) and Malays (1.03 mmol/litre). Rank prevalence of diabetes for males was Indians (highest), Malays and then Chinese; for females it was Malays, Indians, Chinese.

CONCLUSIONS

The higher mortality from ischaemic heart disease found in Indians in Singapore cannot be explained by the major risk factors of cigarette smoking, blood pressure and serum cholesterol; lower high density lipoprotein cholesterol and higher rates of diabetes may be part of the explanation. The higher systolic blood pressures in Malays may explain their higher hypertensive disease mortality.

Differential expression of TGF-beta isoforms by normal and inflammatory bowel disease intestinal myofibroblasts

Intestinal strictures are frequent in Crohn's disease but not ulcerative colitis. We investigated the expression of transforming growth factor (TGF)-beta isoforms by isolated and cultured primary human intestinal myofibroblasts and the responsiveness of these cells and intestinal epithelial cells to TGF-beta isoforms. Normal intestinal myofibroblasts released predominantly TGF-beta(3) and ulcerative colitis myofibroblasts expressed both TGF-beta(1) and TGF-beta(3), whereas in myofibroblast cultures from fibrotic Crohn's disease tissue, there was significantly lower expression of TGF-beta(3) but enhanced release of TGF-beta(2). These distinctive patterns of TGF-beta isoform release were sustained through several myofibroblast passages. Proliferation of Crohn's disease myofibroblasts was significantly greater than that of myofibroblasts derived from normal and ulcerative colitis tissue. In contrast to cells from normal and ulcerative colitis tissue, neutralization of the three TGF-beta isoforms did not affect the proliferation of Crohn's disease intestinal myofibroblasts. Studies on the effect of recombinant TGF-beta isoforms on epithelial restitution and proliferation suggest that TGF-beta(2) may be the least effective of the three isoforms in intestinal wound repair. In conclusion, the enhanced release of TGF-beta(2) but reduced expression of TGF-beta(3) by Crohn's disease intestinal myofibroblasts, together with their enhanced proliferative capacity, may lead to the development of intestinal strictures.

Glycogen synthase kinase-3: functions in oncogenesis and development

Study of GSK-3 had an inauspicious beginning rooted in intermediary metabolism. However, owing to the fortuitous convergence of several disparate areas of biology, the enzyme now offers unique opportunities for study of the control of a variety cellular processes. While at first sight a role in transcriptional regulation appears unlikely for a protein first identified as acting on glycogen synthase, it is even more surprising that the same protein should be functionally interchangeable with a fruit fly homeotic gene. Such understandable scepticism, however, is based on teleological bias. Glycogen synthase is a critical enzyme regulating glucose storage. The c-Jun oncoprotein may have the potential to transform cells but this does not excuse it from similar mechanisms of control to glycogen synthase. Likewise, homeotic genes play a crucial role in setting up the body plan of an embryo but must also be subject to control. The main difference is that when such control is lost, the result is rather graphic. It is, therefore, only to be expected that regulatory protein kinases will surface in superficially quite unrelated areas and that many of their targets will be 'housekeeping' proteins. Perhaps the most difficult aspect of protein phosphorylation research is the linking of physiological substrates with particular protein kinases, hence reconstructing pathways. No matter how compelling in vitro data appear, there must be demonstration that the protein is targeted by the specific protein kinase in cells, an extremely difficult process. Most progress in this respect has been made using genetic analysis in lower organisms, especially yeast. Here another problem arises: demonstration of biochemical linkages underlying genetic interactions which requires function to be ascribed to genes identified by a gross effect. The challenge is to co-ordinate these two approaches, a strategy currently being employed to further unravel the biological role of GSK-3.

Sexual behaviour of young people in international tourist resorts

BACKGROUND/OBJECTIVES

Increasingly, young people travel abroad to experience nightlife in international resorts. Although media coverage of such resorts suggests high levels of sexual activity, little empirical data are currently available. We have measured: 3 year trends in sexual behaviour of young people visiting Ibiza, levels of sexual risk taking, and their relation to substance use. Additionally, in 2002 we identified levels of homosexual sex and sexual interactions between UK residents and individuals from other countries.

METHODS

Data were collected from visitors to Ibiza between 2000 and 2002 just before they left the island. Information on sexual health was surveyed using a short anonymous questionnaire.

RESULTS

Over half of individuals (56.0%) visiting Ibiza had sex with at least one person, with 26.2% of males and 14.5% of females having sex with more than one individual. However, of those arriving without sexual partners (75.5%) just under half (47.5%) have sex in Ibiza and most of these (62.4%) always used condoms. Having any sex abroad was associated with using illicit drugs and having more sexual partners in the 6 months before visiting Ibiza. However, having unprotected sex or sex with more than one person was associated with smoking as well as having higher numbers of sexual partners before their visit. Overall, 8.6% of individuals had sex with a non-UK resident in Ibiza although such individuals were no more likely to have sex without condoms.

CONCLUSIONS

Substantial numbers of individuals visiting international nightlife resorts have unprotected sex with people they meet while abroad. This poses an increasing threat to the sexual health of UK residents but as yet little attention has been paid to developing interventions that might reduce sexual risk taking among young people holidaying abroad.

Risk factors and incident coronary heart disease in Chinese, Malay and Asian Indian males: the Singapore Cardiovascular Cohort Study

OBJECTIVE

This prospective study in Singapore investigated the relationships of established coronary risk factors with incident coronary heart disease (CHD) for Chinese, Malay, and Asian Indian males.

SUBJECTS

A cohort (consisting of 2879 males without diagnosed CHD) derived from three previous cross-sectional surveys.

METHODS

Individual baseline data were linked to registry databases to obtain the first event of CHD. Hazard ratios (HR) or relative risks for risk factors were calculated using Cox's proportional hazards model with adjustment for age and ethnic group and adjustment for age, ethnic group and all other risk factors (overall adjusted).

RESULTS

There were 24,986 person-years of follow-up. The overall adjusted HR with 95% CI are presented here. Asian Indians were at greatest risk of CHD, compared to Chinese (3.0; 2.0-4.8) and Malays (3.4; 1.9-3.3). Individuals with hypertension (2.4; 1.6-2.7) or diabetes (1.7; 1.1-2.7) showed a higher risk of CHD. High low density lipoprotein cholesterol (LDL-C) (1.5; 1.0-2.1), high fasting triglyceride (1.5; 0.9-2.6) and low high density lipoprotein cholesterol (HDL-C) (1.3; 0.9-2.0) showed a lesser but still increased risk. Alcohol intake was protective with non-drinkers having an increased risk of CHD (1.8; 1.0-3.3). Obesity (body mass index > or =30) showed an increased risk (1.8; 0.6-5.4). An increased risk of CHD was found in cigarette smokers of > or =20 pack years (1.5; 0.9-2.5) but not with lesser amounts.

CONCLUSIONS

The increased susceptibility of Asian Indian males to CHD has been confirmed in a longitudinal study. All of the examined established risk factors for CHD were found to play important but varying roles in the ethnic groups in Singapore.

Cardiovascular diseases in Chinese, Malays, and Indians in Singapore. I. Differences in mortality

STUDY OBJECTIVE

The aim of the study was to analyse differences in mortality from the main cardiovascular diseases (ischaemic heart disease, hypertensive disease, and cerebrovascular disease) among Chinese, Malays, and Indians in Singapore.

DESIGN

The study was a survey using national death registration data in Singapore for the five years 1980 to 1984. The underlying cause of death, coded according to the ninth revision of the International Classification of Diseases, was taken for the analyses.

SETTING

The study was confined to the independent island state of Singapore, population 2.53 million (Chinese 76.5%, Malays 14.8%, Indians 6.4%, Others 2.3%). Death registration is thought to be complete.

SUBJECTS

All registered deaths in the age range 30-69 years during the study period were analysed by ethnic group.

MEASUREMENT AND MAIN RESULTS

Indians had higher mortality from ischaemic heart disease than the other ethnic groups in both sexes, with age-standardised relative risks of Indian v Chinese (males 3.8, females 3.4), Indian v Malay (males 1.9, females 1.6), and Malay v Chinese (males 2.0, females 2.2). The excess mortality in Indians declined with age. For hypertensive disease Malays had the highest mortality, with age-standardised relative risks of Malay v Chinese (males 3.4, females 4.4), Malay v Indian (males 2.0, females 2.5), and Indian v Chinese (males 1.6, females 1.6). For cerebrovascular disease there was little ethnic difference except for lower rates in Chinese females, with age-standardised relative risks of Malay v Chinese (males 1.1, females 1.9), Malay v Indian (males 1.0, females 1.1), and Indian v Chinese (males 1.1, females 1.7).

CONCLUSIONS

There are significant differences in mortality from the three main cardiovascular diseases in the different ethnic groups in Singapore.

Identification of multifunctional ATP-citrate lyase kinase as the alpha-isoform of glycogen synthase kinase-3

Multifunctional ATP-citrate lyase kinase (ACLK) exhibits several properties that are similar to glycogen-synthase kinase-3 (GSK-3). The molecular cloning of two distinct mammalian GSK-3 cDNAs and a Drosophila melanogaster (fruitfly) homologue, zeste-white3sgg, has established the existence of a GSK-3 subfamily. A multifunctional protein kinase first identified as an ACLK has recently been shown to exhibit several similarities to the alpha- and beta-forms of GSK-3. Here we have used immunological and biochemical analyses to directly compare these enzymes. Thus purified preparations of ACLK isolated from brain and liver preferentially cross-react with anti-GSK-3 alpha antisera and phosphorylate previously defined substrates of GSK-3 at identical sites. Conversely, both alpha- and beta-forms of GSK-3 phosphorylated ATP-citrate lyase at the same site(s) targeted by ACLK. These, and other similarities, demonstrate ACLK to be identical with, or highly related to, GSK-3 alpha, the implications of which are discussed.

Evolution of the lambda or twin-chorionic peak sign in dichorionic twin pregnancies

OBJECTIVE

To study the sonographic evolutaion of the chorionic tissue projection at the intertwin membrane-placental junction, or lambda sign, or twin-chorionic peak sign, in dichorionic twin pregnancies and to determine the effect of placental location on its prevalence during the first half of pregnancy.

METHODS

We prospectively recruited women with twin pregnancies undergoing sonographic screening for chromosomal abnormalities at 10-14 weeks' gestation for this study. The presence or absence of the lambda sign and the position of the placenta(s) were recorded in all cases. The presence of the lambda sign was evaluated prospectively at 16 and 20 weeks' gestation.

RESULTS

There were 101 twin pregnancies with a lambda sign identified at 10-14 weeks' gestation, 67 with fused placentas and 34 with separate placentas. At 16 weeks, the lambda sign was present in all 67 pregnancies with fused placentas (100%) and in 31 of 34 (91%) pregnancies with separate placentas. At 20 weeks, the lambda sign was present in 25 of the 34 (74%) pregnancies with separate placentas and in 62 of the 67 (93%) with fused placentas. The lambda sign was identified subsequently in none of the 53 pregnancies in which it was absent at 10-14 weeks' gestation.

CONCLUSIONS

At 10-14 weeks' gestation, twin pregnancies with the lambda sign can be classified as dichorionic and pregnancies with absent lambda sign can be classified as monochorionic and therefore monozygotic. At 16-20 weeks, the lambda sign is indicative of dichorionicity but its absence does not exclude dizygosity.

Increased nuchal translucency thickness at 10-14 weeks of gestation as a predictor of severe twin-to-twin transfusion syndrome

The study examines a possible association between increased nuchal translucency thickness at 10-14 weeks of gestation in monochorionic twin pregnancies and the subsequent development of severe twin-to-twin transfusion syndrome (TTS). In 132 monochorionic twin pregnancies, including 16 that developed severe TTS at 15-22 weeks of gestation and 116 that did not develop TTS, crown-rump length, nuchal translucency thickness and fetal heart rate were measured at 10-14 weeks. In those that developed severe TTS, the prevalence of nuchal translucency thickness above the 95th centile of the normal range and the intertwin difference in nuchal translucency thickness and fetal heart rate were significantly higher than in the non-TTS group; there were no significant differences between the groups in the inter-twin difference in crown-rump length. For fetal nuchal translucency above the 95th centile, the positive and negative predictive values for the development of TTS were 38% and 91%, respectively; the likelihood ratios of nuchal translucency above or below the 95th centile for the development of severe TTS were 4.4 (1.8-9.7) and 0.7 (0.4-0.9), respectively. These findings demonstrate that the underlying hemodynamic changes associated with TTS may manifest as increased fetal nuchal translucency thickness at 10-14 weeks of gestation.

Calmodulin-dependent kinase II mediates T cell receptor/CD3- and phorbol ester-induced activation of IkappaB kinase

Numerous fundamental biological processes involve the NFkappaB family of transcription factors. The mechanisms by which this family of proteins is regulated are therefore of widespread importance. In most cells, NFkappaB is bound to inhibitory IkappaB proteins and sequestered in the cytoplasm. NFkappaB-inducing signals result in activation of a large multisubunit kinase complex, IKK, which phosphorylates IkappaB. IkappaB is subsequently degraded, releasing NFkappaB, which translocates to the nucleus. We previously reported that inhibitors of the calcium-binding protein calmodulin (CaM) prevent phorbol ester-induced phosphorylation of IkappaB. Here we show that KN93, an inhibitor of CaM-dependent kinases (CaMKs), also inhibits the phosphorylation of IkappaB. The effect of both CaM and CaMK inhibitors on IkappaB phosphorylation is due to the inhibition of the activity of CaMK II because neither drug has any effect when a derivative of CaMK II that is insensitive to these inhibitors is expressed. When CaMK II is inhibited, phorbol ester is no longer able to activate IKK, placing CaMK II in the signaling pathway that leads to IKK activation. CaM and CaMK inhibitors also block T cell receptor/CD3-induced activation but have no effect on the ability of the cytokine tumor necrosis factor alpha or the phosphatase inhibitor calyculin A to induce degradation of IkappaB. Finally we show that expression of a constitutively active CaMK II results in the activation of NFkappaB. The results identify CaMK II as a mediator of IKK activation specifically in response to T cell receptor/CD3 and phorbol ester stimulation.