Effects of menstrual cycle phase on metabolomic profiles in premenopausal women.

BACKGROUND: Characterization of the normal degree of physiological variation in the metabolomic profiles of healthy humans is a necessary step in the development of metabolomics as both a clinical research and diagnostic tool. This study investigated the effects of the menstrual cycle on (1)H nuclear magnetic resonance (NMR) derived metabolomic profiles of urine and plasma from healthy women. METHODS: In this study, 34 healthy women were recruited and a first void urine and fasting blood sample were collected from each woman at four different time points during one menstrual cycle. Serum hormone levels were used in combination with the menstrual calendar to classify the urine and plasma samples into five different phases i.e. menstrual, follicular, periovulatory, luteal and premenstrual. The urine and plasma samples were analysed using (1)H NMR spectroscopy and subsequent data were analysed using principal component analysis (PCA) and partial least squares discriminant analysis. RESULTS: PCA of the urine spectra showed no separation of samples based on the phases of the menstrual cycle. Multivariate analysis of the plasma spectra showed a separation of the menstrual phase and the luteal phase samples (R(2) = 0.61, Q(2) = 0.41). Subsequent analysis revealed a significant decrease in levels of glutamine, glycine, alanine, lysine, serine and creatinine and a significant increase in levels of acetoacetate and very low density lipoprotein (VLDL CH(2)) during the luteal phase. CONCLUSIONS: These results establish a need to control for metabolic changes that occur in plasma due to the menstrual cycle in the design of future metabolomic studies involving premenopausal women.

Familial early-onset type 2 diabetes in Chinese patients: obesity and genetics have more significant roles than autoimmunity.

OBJECTIVE: We examined the prevalence of different forms of diabetes in Hong Kong Chinese patients with familial early-onset type 2 diabetes and compared their clinical features with patients with familial late-onset type 2 diabetes. RESEARCH DESIGN AND METHODS: A total of 145 young patients with early-onset diabetes (age and age at diagnosis < or = 40 years) and a family history of diabetes were studied. They were screened for mutations in the genes encoding glucokinase, hepatocyte nuclear factor (HNF)-4alpha, and HNF-1alpha. The mitochondrial DNA A-->G at nucleotide 3243 (mt3243) and amyLin S20G mutations were studied, and antibodies to GAD (anti-GADs) were also examined. RESULTS: The prevalence of putative diabetogenic gene mutations and autoimmune markers were 4% for glucokinase, 0% for HNF-4alpha, 5% for HNF-1alpha, 3% for mt3243, 2% for amylin 520G, and 4% for anti-GAD. Compared with late-onset patients, the patients with early-onset diabetes had a higher prevalence of a parental history of diabetes and were generally more obese. When classified by obesity indexes (BMI and waist circumference), the obese patients, especially those with early-onset diabetes, had a clustering of cardiovascular risk factors and increased rates of retinopathy and albuminuria. CONCLUSIONS; Genetic factors (up to 14%) and obesity (55%) play more significant roles than autoimmunity (4%) in familial type 2 diabetes in young Chinese patients. The significance of obesity-related genes and other gene-gene and gene-environment interactions in these young patients remains to be determined.

The islet amyloid polypeptide (amylin) gene S20G mutation in Chinese subjects: evidence for associations with type 2 diabetes and cholesterol levels.

BACKGROUND AND OBJECTIVES: There has been evidence that the S20G mutation in the islet amyloid polypeptide (amylin) gene may be associated with type 2 diabetes. In the present study, we investigated the distribution of the mutation in Hong Kong Chinese, and examined whether there was evidence for associations between the mutation and type 2 diabetes and/or metabolic profiles. SUBJECTS AND METHODS: This study involved 227 early and 235 late-onset (defined as onset age < or = 40 and > 40 years, respectively) type 2 diabetic patients, as well as 126 nondiabetic subjects. The mutation was detected using a PCR-RFLP method. RESULTS: We identified six (2.6%) and one (0.4%) patients heterozygous for the mutation from the early and late-onset groups, respectively (P = 0.05). None of the nondiabetic subjects had the mutation. Insulin deficiency and poor glycaemic control were not common findings amongst carriers of the mutation. In the early onset group, the patients with the mutation had lower plasma levels of total (4.3 +/- 0.9 mmol/l vs. 5.3 +/- 1.1 mmol/l, P = 0.02) and low density lipoprotein (LDL)-cholesterol (2.3 +/- 0.7 mmol/l vs. 3.2 +/- 0.9 mmol/l, P = 0.01) than those without the mutation. CONCLUSIONS: Our data suggest that the islet amyloid polypeptide gene mutation might be associated with early occurrence of type 2 diabetes and lower plasma levels of total and low density lipoprotein-cholesterol in the Chinese population.

Association studies of variants in promoter and coding regions of beta-cell ATP-sensitive K-channel genes SUR1 and Kir6.2 with Type 2 diabetes mellitus (UKPDS 53).

AIMS: The beta-cell ATP-sensitive potassium channel consists of two subunits, SUR1 and Kir6.2. Population association studies have shown that three variants in SUR1 and one in Kir6.2 are associated with Type 2 diabetes. These polymorphisms do not result in a functional change or affect splicing, suggesting that they could be in linkage disequilibrium with a pathogenic mutation. The present study aimed firstly to screen the promoter regions of SUR1 and Kir6.2 to determine whether mutations in linkage disequilibrium with the silent variants lie in regulatory regions, which might lead to changes in gene expression. Secondly, novel and previously described variants associated with Type 2 diabetes (SUR1 exon 16-3t, exon 18 T, and Kir6.2 E23K) were investigated in the UKPDS cohort. METHODS: The promoter sequences of both genes were screened by single-stranded conformational polymorphism analysis for variants associated with Type 2 diabetes. The previously reported variants were evaluated in 364 Type 2 diabetic and 328 normoglycaemic control subjects. RESULTS: Two variants were detected in the SUR1 promoter, a three base insertion (caa) at -522 bp and a single base substitution at - 679 bp (c-->g). Neither of the variants were associated with diabetes, nor were they in a sequence consensus region for transcription factors. No association with diabetes was observed for either SUR1 variant. However, in contrast, analysis of the Kir6.2 E23K variant showed that the KK homozygosity was more frequent in Type 2 diabetic than control subjects. Variants were not associated with clinical characteristics nor did they affect response to sulphonylurea therapy CONCLUSION: There is no support at present for mutations in either Kir6.2 or SUR1 promoter sequences contributing to Type 2 diabetes. However, the minimal promoter region of SUR1 has yet to be investigated. The E23K variant of Kir6.2 is associated with Type 2 diabetes mellitus in the UKPDS cohort.

Butyrylcholinesterase K variant on chromosome 3 q is associated with Type II diabetes in white Caucasian subjects.

AIMS/HYPOTHESIS: To determine the association of three genes associated with Alzheimer's disease--butyrylcholinesterase (BcHE) on chromosome 3 q, alpha2 macroglobulin (alpha2M) on chromosome 12 p and apolipoprotein E (ApoE) on chromosome 19 q--with Type II (non-insulin-dependent) diabetes mellitus. METHODS: Frequencies of BcHE K variant, alpha2M insertion and/or deletion polymorphism, the ApoE common polymorphisms and promoter variants at ApoE-491 and -291, were examined by fluorescent RFLP in DNA from 276 United Kingdom Prospective Diabetes Study Type II diabetic subjects and 351 non-diabetic subjects from the Diabetes In Families study. Genetic data in diabetic subjects was analysed in relation to clinical characteristics and islet function as assessed by the requirement for insulin therapy 6 years after randomisation. RESULTS: The BcHE K variant allele was more common among Type II diabetic subjects (D) than non-diabetic subjects (ND) (22.8 % D vs 15.8 % ND; p = 0.00 017). Subjects homozygous for the variant were more frequent in the diabetic group (5.8 % D vs 2.6 % ND: p = 0.00 056). The K variant allele frequency was not associated with a requirement for insulin therapy (29.0 % insulin-requiring vs 21.8 % non-insulin-requiring; p = 0.121). There were no associations of alpha2M and ApoE polymorphisms or ApoE promoter variants with clinical characteristics or insulin requirement in diabetic subjects. There were differences in total cholesterol (p = 0.0005) and LDL-cholesterol (p = 0.0009) among non-diabetic subjects in relation to ApoE-491 genotypes. CONCLUSION/INTERPRETATION: The association of the BcHE gene (3q26) with Type II diabetes could be related to an identified susceptibility locus on chromosome 3q27 but appears to be independent of islet function. The absence of diabetes-specific associations with alpha2M, ApoE or ApoE promoter variants suggest that these are not important in the onset of hyperglycaemia.

Sequence variants of the sarco(endo)plasmic reticulum Ca(2+)-transport ATPase 3 gene (SERCA3) in Caucasian type II diabetic patients (UK Prospective Diabetes Study 48).

AIMS/HYPOTHESIS: Type II (non-insulin-dependent) diabetes mellitus is a common heterogeneous metabolic disorder of largely unknown genetic aetiology. The sarco(endo)plasmic reticulum Ca(2+)-transport ATPase (SERCA) plays an important part in the glucose-activated beta-cell Ca(2+) signalling that regulates insulin secretion. Impaired function and expression of SERCA have been shown in islets of Langerhans from diabetic animal models and have also been associated with beta-cell apoptosis. Thus, the SERCA3 encoding gene is a plausible candidate for a primary pancreatic beta-cell defect. METHODS: In this study, the entire coding and the promoter regions of SERCA3 gene were screened by single-strand conformation polymorphism analysis in white Caucasian Type II diabetic patients. RESULTS: We found four rare missense mutations [Exon 4: Gln(108)-->His (CAG-->CAT), Exon 14: Val(648) -->Met (GTG-->ATG) and Arg(674)-->Cys (CGC--> TGC), and Exon 15: Ile(753)-->Leu (ATC-->CTC)]. The patients with Gln(108)-->His, Val(648)-->Met and Arg(674)-->Cys mutations, which may affect the E1P-E2P transition of SERCA3 during its enzyme cycle, had normal body weight with marked hyperglycaemia and beta-cell dysfunction. That is an unusual phenotype only found in 6 % of the Type II diabetic patients recruited for the UK Prospective Diabetes Study. In addition, five silent polymorphisms, six intron variants and two polymorphisms in the 3' untranslated region of exon 22 were found with similar frequency in diabetic and control subjects. CONCLUSION/INTERPRETATION: Our result suggests that in white Caucasians, the SERCA3 locus possibly contributes to the genetic susceptibility to Type II diabetes [Diabetologia (1999) 42: 1240-1243].

Physical mapping of the human T-cell receptor beta gene complex, using yeast artificial chromosomes.

Yeast artificial chromosomes (YACs) were used to construct a physical map of the germline human T-cell beta chain gene complex (TCRB). Variable region genes (BV) for the 25 known subfamilies were used as probes to screen the ICRF AM4x YAC library. Of the five positive YACs identified, one YAC designated B3, 820 kilobase pairs (kbp) in size, scored positive for all 25 TCRBV subfamilies plus the constant region genes (BC) when analyzed by pulse field gel electrophoresis. Restriction enzyme mapping of B3 located TCRBV and TCRBC gene regions to 4 Sfi I fragments of 280 110, 90, and 125 kbp and was in accordance with published data. In addition comparison of hybridization results of Sfi I-restricted B3 and genomic DNA from the parental cell line GM1416B revealed identical banding patterns. The data thus showed YAC B3 encoded a complete and unrearranged TCRB gene locus of some 600-620 kbp. The map was further resolved by locating restriction sites for Sal I and Bss HII on B3, giving more precise localization of the individual TCRBV gene families. Fluorescent in situ hybridization of B3 to spreads of human metaphase chromosomes localized B3 to 7q35. However, two additional signals were obtained; one attributable to the TCRBV orphon cluster on 9p21, the second to the long arm of chromosome 2. Polymerase chain reaction amplification of a chromosome 2 somatic cell hybrid, using primers for all 25 TCRBV gene families, revealed that the signal was not attributable to a second orphon cluster. It is suggested that B3 is a chimeric YAC with an intact TCRB locus flanked by chromosome 2 sequences.

Studies on liver profile after prolonged praziquantel courses for schistosomiasis mansoni in Egyptian children on a field level.

The effect of prolonged praziquantel courses on the clinical, sonographic and functional aspects of the liver in bilharzial and nonbilharzial school-children on village level was investigated in this study. Bilharzial--positive school--children were divided into three groups according to Praziquantel regimes. Each case received an initial dose of 40 mg/Kg. PZQ. Subsequently the first group received 6-monthly full dose, the second group received 3-monthly half doses and the third group received monthly half doses. Another 3 groups of bilharzial negative children were used as a control receiving oral vitamin B complex as placebo. Clinico-parasitological and sonographic examinations as well as liver function tests were done before and after drug administration. It was concluded according to our results that healing of hepatic pathology was slower than parasitological cure. Moreover complete reversibility of hepatic size required frequent praziquantel doses (from 3 to 7). Hepatic healing is dose related. Less doses are required for parasitological cure.