Phosphatase and tension homolog overexpression in insulin resistant diabetic adipose tissue.

OBJECTIVE: To investigate the expression of phosphatase and tension homolog (PTEN) in adipose tissue of KKAy diabetic mice, a mouse model of type 2 diabetes. METHODS: KKAy diabetic mice were fed with high fat diet for 4 weeks. After blood glucose met the criteria of diabetes (over 16.7 mmol/L), mice were randomly divided into 3 groups: a control group (without any treatment), a rosiglitazone group (treated with rosiglitazone 12.5 mg/kg.d once per day), and a metformin group (treated with metformin 3 g/kg.d twice daily). After 4 weeks, we then determined the expression of PTEN and phosphoserine 473-Akt (pS473-Akt) in the epididymal adipose tissue with Western blots. The mice in each group were further divided into the insulin (-) subgroup and insulin (+) subgroup, which were intraperitoneally injected with saline and insulin (5 mU/g body weight), respectively. RESULTS: The expression of PTEN was elevated in the epididymal adipose tissue obtained from KKAy diabetic mice compared with that from the C57BL/6J mice (P<0.001). In accordance with the enhanced expression of PTEN, the level of pS473-Akt stimulated by insulin was decreased in the adipose tissue of KKAy mice compared to the C57BL/6J mice (P<0.001). Treatment with the insulin-sensitizing agents, rosiglitazone and metformin did not inhibit the elevated expression of PTEN in adipose tissue of KKAy diabetic mice. CONCLUSION: PTEN may play an important role in the development of insulin resistance in adipose tissue of type 2 diabetes mice model.

Association between glucose fluctuation during 2-hour oral glucose tolerance test, inflammation and oxidative stress markers, and ß-cell function in a Chinese population with normal glucose tolerance.

BACKGROUNDS: Glucose fluctuation (GF) may have detrimental effects in individuals with diabetes; however, clinical data on the association between short-term GF, inflammation/oxidative stress markers, and islet ß-cell function based on a population with normal glucose tolerance (NGT) are insufficient. Therefore, we aimed to explore these associations in a Chinese population of 209 individuals with NGT in a cross-sectional analysis. METHODS: Individuals were categorized based on GF tertiles, calculated as the maximum-minimum glucose levels among four time points (0, 30, 60, 120 min) during 2-hour oral glucose tolerance test (OGTT). Plasma inflammation markers tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), and oxidative stress markers superoxide dismutase (SOD), and 8-oxo-2'-deoxyguanosine (8-oxo-dG) were measured. Islet ß-cell function was estimated according to the disposition index (DI) at the early (30 min) and total (120 min) phase of the OGTT, adjusted for insulin sensitivity. RESULTS: Individuals in the middle and highest tertile of GF had reduced ß-cell function, and increased plasma SOD and TNF-α levels compared with those in the lowest tertile of GF (P<0.05). Multiple linear regression analysis indicated that GF was positively associated with TNF-α, 8-oxo-dG and SOD levels, but negatively associated with ß-cell function, whereas IL-6, TNF-α, 8-oxo-dG and SOD levels were negatively associated with ß-cell function (P<0.05). CONCLUSIONS: GF may increase inflammation and oxidative stress markers in individuals with NGT, which could contribute to reduced ß-cell function. Thus, maintaining glucose stability after a meal may have beneficial effects on delaying ß-cell dysfunction, suggesting that diet and exercise strategies to decrease diet related GF are warranted.

High serum triglyceride levels in the early first trimester of pregnancy are associated with gestational diabetes mellitus: A prospective cohort study.

AIMS/INTRODUCTION: Pregnant women with gestational diabetes mellitus (GDM) have been reported to have higher serum triglyceride (TG) levels during the entire gestational period. However, whether TGs contribute to the incidence of GDM remains unclear. This study aimed to evaluate whether higher serum TG level during early first trimester is associated with GDM. MATERIALS AND METHODS: A prospective single-center cohort study was carried out among pregnant women (n = 2,949) who received regular antenatal care in Fu Xing Hospital, Capital Medical University, Beijing, China. GDM was diagnosed between 24 and 28 gestational weeks. Serum TG levels were measured during gestational weeks 6-8 (TG0) and 16-18 (TG1). TG elevation was the difference between TG1 and TG0. RESULTS: In total, 581 pregnant women developed GDM. A 13.1, 18.5 and 28.8% incidence of GDM was observed in women with low, referent and high TG0 levels, respectively. Among women with prepregnancy body mass index <24 kg/m2 and prepregnancy body mass index ≥24 kg/m2 , those with high TG0 levels had 2.4- and 2.3-fold increased odds of developing GDM, respectively, compared with pregnant women with low TG0 levels. A positive dose-response relationship was observed between continuous TG0 and TG elevation, and the odds of GDM; a positive association was observed between TG elevation and the odds of developing GDM in pregnant women with intermediate to high TG0 levels. CONCLUSION: High TG level during the early first trimester, and TG elevation from the first to early second trimester are associated with GDM development, which persists even after adjusting for confounders.

TNFα Mediates the Interaction of Telomeres and Mitochondria Induced by Hyperglycemia: A Rural Community-Based Cross-Sectional Study.

This study is aimed at evaluating the relationship between leukocyte telomere length (LTL) and mitochondrial DNA copy number (mtDNAcn) in a noninterventional rural community of China with different glucose tolerance statuses. In addition, we investigate whether the indicators of oxidative stress and inflammation were involved and identify mediators among them. A total of 450 subjects in rural China were included and divided into two groups according to a 75 g oral glucose tolerance test (OGTT): the abnormal glucose metabolism (AGM, n = 257, 57.1%) group and the normal glucose tolerance (NGT, n = 193, 42.9%) group. Indicators of oxidative stress (superoxide dismutase (SOD) and glutathione reductase (GR)) and inflammatory indices (tumor necrosis factor α (TNFα) and interleukin-6 (IL-6)) were all determined by ELISA. LTL and mtDNAcn were measured using a real-time PCR assay. Linear regressions were used to adjust for covariates that might affect the relationship between LTL and mtDNAcn. Mediation analyses were utilized to evaluate the mediators. In the AGM, LTL was correlated with mtDNAcn (r = 0.214, p = 0.001), but no correlation was found in the NGT. The association between LTL and mtDNAcn was weakened after adjusting for inflammatory factors in the AGM (p = 0.087). LTL and mtDNAcn were both inversely related to HbA1c, IL-6, TNFα, and SOD activity. Mediation analysis demonstrated that TNFα was a significant mediator in the telomere-mitochondrial interactome in the AGM. This result suggests that inflammation and oxidative stress may play a vital role in telomere shortening as well as mitochondrial dysfunction. In the subjects with hyperglycemia, a significant positive correlation is observed between LTL and mtDNAcn, which is probably mediated by TNFα. TNFα may be considered a potential therapeutic target against aging-related disease in hyperglycemia.

Relationship between Decreased Serum Superoxide Dismutase Activity and Metabolic Syndrome: Synergistic Mediating Role of Insulin Resistance and ß-Cell Dysfunction.

The interplays of cellular aging and oxidative stress (OS) markers form a complex network, which has been reported to be interrelated with numerous age-related and metabolic diseases, including metabolic syndrome (MS). However, given the multifactorial mechanisms of MS, several important confounders such as dietary factors and the reciprocal effect among these markers have not been considered and adjusted in previous investigations regarding the associations of cellular aging and OS markers with MS and its related metabolic abnormalities. To explicate this, we conducted a cross-sectional study among 533 Chinese adults. All the participants underwent a 75 g oral glucose tolerance test. Dietary data were collected via a 24-hour dietary recall and subsequently analyzed by a registered dietitian using nutrition calculation software. Clinical diagnosis of MS was made according to the revised National Cholesterol Education Program Adult Treatment Panel III criteria (2004) with waist circumference cutoff modified for an Asian population. The leukocyte telomere length, mitochondrial DNA copy number, 8-hydroxy-2-deoxyguanosine, superoxide dismutase (SOD) activity, and glutathione reductase were examined. SOD activity was significantly decreased in MS subjects (62.06 ± 16.89 U/mL vs. 56.25 ± 22.61 U/mL, P = 0.001) and exhibited a descending trend across sequential increase of MS component number (P for trend = 0.031). SOD activity is modestly correlated with glucose indicators and insulin sensitivity and ß-cell function indices and was independently and negatively correlated with the level of triglyceride. An independent association between SOD activity and MS was observed after adjusting for metabolic indicators, dietary factors, cellular aging, and OS markers, as well as insulin sensitivity and ß-cell function indices. However, the statistical significance of the association between SOD activity and MS was attenuated after adjusting for the Matsuda insulin sensitivity index (ISIM) and insulin secretion-sensitivity index-2 (ISSI-2), suggesting a possible mediating effect. Therefore, we conducted a mediation model analysis, which showed that decreased ISIM and ISSI-2 partially and synergistically mediated the contribution of decreased SOD activity to MS. In conclusion, decreased SOD activity is an independent predictor for increased risk of MS, and insulin resistance and ß-cell dysfunction partially mediate the relationship between decreased SOD activity and MS.

C-Peptide: A Mediator of the Association Between Serum Uric Acid to Creatinine Ratio and Non-Alcoholic Fatty Liver Disease in a Chinese Population With Normal Serum Uric Acid Levels.

Background: The data on the relationship between normal-ranged serum uric acid (SUA), ß-cell function, and non-alcoholic fatty liver disease (NAFLD) are complicated and insufficient. Moreover, uric acid is excreted by kidney, and SUA levels may be affected by renal function. Thus, we introduced a renal function-normalized index [serum uric acid to creatinine ratio (SUA/Cr)] into the study and explored the association between SUA/Cr, C-peptide and NAFLD in a Chinese population with normal SUA levels by a cross-sectional analysis. Materials and Methods: A total of 282 individuals with normal SUA levels and different glucose tolerance status from a diabetes project were included in the study (mean age = 53.7± 10.5 years; women = 64.50%). NAFLD was diagnosed by abdominal ultrasonography (NAFLD, n=86; without NAFLD, n=196). Trapezoid formula was used to calculate area under the curve of C-peptide (AUCCP) from 4 points (including 0, 30,60, and 120min) during 2-h oral glucose tolerance test. Spearman correlation analysis was used to explore the correlation between SUA/Cr, AUCCP and NAFLD risk factors. Multiple logistic regression analysis was used to explore the association between SUA/Cr or AUCCP and NAFLD. Mediation analysis was used to explore whether AUCCP mediated the association between SUA/Cr and NAFLD. Results: Individuals with NAFLD had significantly higher SUA/Cr and AUCCP than those without NAFLD(P<0.05). Spearman correlation analysis showed that both SUA/Cr and AUCCP were significantly associated with many NAFLD risk factors, and SUA/Cr was positively correlated with AUCCP (P<0.05). Multiple logistic regression analysis indicated that SUA/Cr and AUCCP were positively associated with NAFLD incidence (P<0.05). Medication analysis indicated that SUA/Cr had a significant direct effect on NAFLD (ß =0.5854, 95% CI: 0.3232-0.8966), and AUCCP partly mediated the indirect effect of SUA/Cr on NAFLD incidence (ß =0.1311, 95% CI: 0.0168-0.4663). Conclusions: SUA/Cr was positively associated with NAFLD incidence, and AUCCP partly mediated the association in a Chinese population with normal SUA levels. Thus, we should pay more attention to high-normal SUA and C-peptide levels due to their predictive power in NAFLD incidence.

Association Between Leukocyte Mitochondrial DNA Copy Number and Non-alcoholic Fatty Liver Disease in a Chinese Population Is Mediated by 8-Oxo-2'-Deoxyguanosine.

Background: Alterations in mitochondrial DNA are potentially associated with oxidative stress and may be involved in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). However, the association between mitochondrial DNA copy number (mtDNAcn) and NAFLD was not consistent. In addition, the association between inflammation and NAFLD has not been established yet. The present study, based on a Chinese population of individuals with different glucose statuses, aimed to explore the association between leukocyte mtDNAcn, markers of oxidative stress, and inflammation and NAFLD. Methods: A total of 318 participants from a diabetes project were included. NAFLD was diagnosed by ultrasonography. Leukocyte mtDNAcn was determined by PCR assay. The levels of the inflammation markers tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6) and the oxidative stress markers glutathione reductase (GR), superoxide dismutase (SOD), and 8-oxo-2'-deoxyguanosine (8-oxo-dG) were also measured. Results: Participants with NAFLD (n = 105) exhibited significantly higher leukocyte mtDNAcn, IL-6, and 8-oxo-dG (all P < 0.05). Pearson correlation analysis indicated mtDNAcn was negatively associated with age, uric acid, SOD, and TNF-α, but was positively associated with 8-oxo-dG (all P < 0.05). Univariate logistic regression analysis revealed that mtDNAcn was positively associated with NAFLD [odds ratio (OR) = 1.617, 95% confidence interval (CI) = 1.036-2.525; P = 0.034]. However, after adjustment for 8-oxo-dG, this association was no longer statistically significant (OR = 1.534, 95% CI = 0.979-2.403, P = 0.062). Moreover, the stress marker 8-oxo-dG was independently associated with NAFLD after adjustment for mtDNAcn, IL-6, glucose tolerance status, and other conventional NAFLD risk factors (OR = 1.707, 95% CI =1.142-2.550, P = 0.009). Mediation analysis indicated that 8-oxo-dG fully mediated the effect of mtDNAcn on the incidence of NAFLD (direct effect ß = 0.5221, 95% CI = -0.0648 to 1.2504; indirect effect ß = 0.0946, 95% CI = 0.0049-0.2463). Conclusions: In a Chinese population, the association between leukocyte mtDNAcn and NAFLD was fully mediated by high levels of 8-oxo-dG. Thus, oxidative stress may be an important driver of NAFLD, and clinical interventions aimed at decreasing oxidative stress to improve NAFLD warrant further research.

Negative association between antioxidant vitamin intake and non-alcoholic fatty liver disease in Chinese non-diabetic adults: mediation models involving superoxide dismutase.

We aimed to explore the association between antioxidant vitamin intake, oxidative stress related markers and non-alcoholic fatty liver disease (NAFLD) by a cross-sectional analysis. A total of 241 non-diabetic participants from a Chinese rural cohort were included. NAFLD was diagnosed by abdominal ultrasound (NAFLD, n = 71; Non-NAFLD, n = 171). Dietary intake was assessed by a 24-h food recall. Plasma oxidative stress related markers superoxide dismutase (SOD), glutathione reductase (GR) and 8-oxo-2'-deoxyguanosine(8-oxo-dG) were measured. The association between dietary antioxidant vitamin intake, oxidative stress related markers and NAFLD were analysed by Spearman correlation analysis and multiple logistic regression analysis. Mediation models were established to examine whether SOD mediated the association between dietary vitamin A or α-tocopherol intake and NAFLD. Spearman correlation analysis indicated that dietary vitamin A and α-tocopherol intake were positively correlated with SOD (p < .05). Multiple logistic regression analysis found plasma SOD, dietary vitamin A and α-tocopherol intake were inversely associated with NAFLD (all p < .05). Mediation analysis indicated that SOD significantly mediated the indirect effect of dietary α-tocopherol (mediated effect = 13.21% total effect) or vitamin A (mediated effect = 3.12% total effect) intake on NAFLD. Our study indicated that dietary vitamin A and α-tocopherol intake may contribute to protect from NAFLD in Chinese non-diabetics, and the associations were partly mediated by SOD. However, SOD only accounted for a minor percentage of the association between vitamin A intake and NAFLD. Thus, other mechanisms underlying antioxidant vitamin' protective effect on NAFLD need further exploration.

Insulin treatment affects leukocyte telomere length in patients with type 2 diabetes: 6-year longitudinal study.

OBJECTIVE: Many studies demonstrated a close relationship between type 2 diabetes mellitus (T2DM) and leukocyte telomere length (LTL). However, how the LTL changes in T2DM and what are the potential causal factors in it, particularly in patients during a long period treatment, have not been studied. Here we performed a longitudinal observation of LTL in trained T2DM patients during a 6-year follow-up and evaluated the possible risk factors that were associated with LTL alteration. METHODS: Seventy-six patients with T2DM were enrolled in this 6-year longitudinal study. The enrolled patients had no severe complication and had never received insulin therapy by the time. Patients were scheduled to visit once every one or two months and their medication changes were recorded. The LTL at the time when patients were enrolled was used as baseline, which was compared with the LTL at 6 year. Multivariable linear regression and exact logistic regression model were adopted to identify independent predictors of telomere length change and telomere length shortening, respectively. RESULTS: Sixty-four patients were successfully followed up. Although mean LTL decreased after 6 years, 30% (19/64) of patients demonstrated LTL lengthening and 70% (45/64) of patients demonstrated LTL shortening. Among them, 18 Patients received insulin treatment during the 6 years. Of these 18 patients, 16 patients showed decreased LTL and only two showed increased LTL. Linear regression analysis demonstrated that change in telomere length during the 6 years was associated inversely with insulin use (ß-coefficients: -0.587, 95% CI: -0.198, -0.085, P < 0.001). Exact logistic regression analysis showed insulin use (OR: 17.355, 95% CI: 2.659, 35.627, P = 0.013) and LDL-C(OR: 3.493, 95% CI: 1.559, 10.063, P = 0.007)were independent predicts of telomere length shortening. CONCLUSIONS: LTL may increase as well as decrease in T2DM who received antidiabetic treatment. Insulin use may accelerate telomere attrition. Insulin use and LDL-C can predict telomere shortening.

Beneficial effects of a diabetes specific formula on insulin sensitivity and free fatty acid in patients with type 2 diabetes mellitus.

BACKGROUND: This prospective, randomized, controlled study was designed to investigate the effects of a diabetes specific formula (Diason low energy: 313.8 kJ/100 ml), compared with a standard formula, on insulin sensitivity, serum C peptide, serum lipids and free fatty acid (FFA) in type 2 diabetics. METHODS: In total of 71 type 2 diabetics completed the study. Enteral formulas were given orally as the sole source of nutrition to the subjects for 6 days. Venous blood samples (0.5, 1, 2, 3 hours) were collected at day-7 after a 75 g oral glucose tolerance test (OGTT), day 1 after a standard test meal (1673.6 kJ) and after 6 days of either the test diabetes specific formula or a standard formula. Plasma glucose, serum insulin, C peptide and lipids were measured. RESULTS: After the intervention period, the diabetes specific formula resulted in a significantly lower postprandial rise in blood glucose concentrations at 0.5 hour (P < 0.05) and 1 hour (P < 0.01); significantly lower peak height of plasma glucose (P = 0.05); significantly lower plasma insulin concentrations at 0.5 hour (P < 0.01), 1 hour (P < 0.01) and 2 hours (P < 0.01); and a significantly lower plasma insulin peak compared to controls; both OGTT and a standard test meal (P < 0.05). The glucose and insulin area under the curve after the diabetes specific formula compared to the standard formula were significantly lower. The C peptide level was lower after 6 days of both nutrition formulas compare to 75 g OGTT, but not different from the standard mixed meal. Both formulas were well tolerated. CONCLUSIONS: In summary the diabetes specific formula with a relatively high monounsaturated fatty acid and high multi fiber proportion significantly improved glycemic control. On top of this, the insulin sensitivity (HOMA-IS) was significantly improved and may therefore directly improve the impact on long term complications. The disease specific formula should therefore be the preferred option to be used by diabetic and hyperglycemic patients in need of nutritional support.

[The effect of enteral nutritional suspension (diabetes) (TPF-DM) on blood glucose, serum insulin and lipids in patients with type 2 diabetes].

OBJECTIVE: To investigate the effect of a new enteral nutrition suspension (diabetes) (TPF-DM) (Dixson 0.75 kcal/ml) (1 kcal = 4.184 kJ) on blood glucose, serum insulin and lipids as compared with a standard formula (Nutrition MF 0.75 kcal/ml) in patients with type 2 diabetes. METHODS: A randomized, controlled, paralleled and single center trial was carried out. A total of 76 patients with type 2 diabetes without using insulin and obvious complications were randomized into a study group and a control group. 36 patients in the study group and 35 in the control group completed the trial. The observation lasted 6 days. All calories came from enteral nutrition. At baseline all the patients had standard mixed meal (bread 50 g, egg 50 g, milk 250 ml, total calorie 400 kcal) test and at the end of the trial a enteral nutrient meal (enteral nutrient 400 ml, total calorie 300 kcal) test. Blood samples were taken before the meal and 30, 60, 120 and 180 minutes after the meal to test plasma glucose, serum insulin, serum lipids and some safety parameters. The area under curve (AUC) for plasma glucose, serum insulin, serum lipids was calculated. RESULTS: Compared with the mixed meal test, the AUC of plasma glucose and serum insulin during both Dixson 0.75 kcal/ml test and standard formula (Nutrition MF 0.75 kcal/ml) test were significantly lower (P < 0.01). The change at baseline in the study group was more than that in the control group [the change of AUC for plasma glucose (-6.42 +/- 8.62) h x mmol x L(-1) vs (-1.87 +/- 5.30) h x mmol x L(-1), P < 0.01; that of AUC for serum insulin (-36.94 +/- 49.77) h x mIU x L(-1) vs (-18.20 +/- 32.62) h x mIU x L(-1), P < 0.05]. Both the enteral nutrition formula can reduce insulin resistance (calculated by HOMA-IR), but there was no difference between them. There was no significant effect on total cholesterol, high density lipoprotein and low density lipoprotein. AUC of serum triglycerides was lower during the tests with both enteral nutrients than that during mixed meal test, but there was no significant difference between the two groups. There was no safety concern about the enteral nutrition. CONCLUSION: Enteral nutrition suspension (diabetes) (TPF-DM) (Dixson 0.75 kcal/ml) is an effective and safe enteral nutrient to be used in patients with type 2 diabetes.

[Effect of Gymnadenia conopsea alcohol extract on pulmonary fibrosis of rats exposed to silica and the expression of tumor necrosis factor-alpha].

OBJECTIVE: To study the roles of Gymnadenia conopsea alcohol extract on pulmonary fibrosis of rats exposed to silica and the expression of TNF-alpha. METHODS: The 120 Wistar rats were randomly divided into control group, silica group and gymnadenia conopsea alcohol extract combined with SiO2 group (combined group). Silica was injected intratracheally to the rats of silica group and combined group, while mitte tales doses physiological saline was injected intratracheally to the rats of control group. Gymnadenia conopsea alcohol extract 2ml (10g/kg) were intragastric administrated to the rats of combined group every day after silica was injected intratracheally to the rats one day, however mitte tales doses physiological saline were intragastric administration to the rats of control group and silica group. I and III collagen were detected by sirius red polarization microscopy. TNF-alpha proteins in paraffin-embedded lung sections were immunohistochemistrily stained on tissue microarray with PV method. RESULTS: In comparison with those of silica groups, the coefficient of lung organ to body of rats in combined groups decreased significantly (P < 0.01). In comparison with those of silica groups, I collagens of combined groups decreased (P < 0.01) and III collagen decreased significantly at the 14th and 21st day (P < 0.05, P < 0.01). The integrated optical densities of TNF-alpha expression in the lung tissue of combined group reduced (P < 0.01) in comparison with those of silica groups. CONCLUSION: Gymnadenia conopsea alcohol extract could inhibit pulmonary fibrosis and the expression of TNF-alpha in lung tissue of rats exposed to silica.

[Effects of Gymnadenia conopsea alcohol extract on collagen synthesis in rat lungs exposed to silica and its mechanism of antioxidative stress].

OBJECTIVE: To explore the effects of Gymnadenia conopsea alcohol extract (GcAE) on the collagen synthesis in rat lungs exposed to silica and the influence on antioxidase activities, level of lipid peroxidation (LPO). METHODS: One hundred and twenty rats were randomly divided into control group, silica group, and GcAE-treated group. Silicotic animal models were established by direct tracheal instillation of silica into rat lungs surgically. From the second day of model establishment, rats in GcAE-treated group were orally given GcAE [8 g/(kg x d) corresponding to raw herb]. At 7, 14, 21, 28 and 60 days after establishment of the animal model, eight rats in each group were sacrificed, and samples were collected. The malondialdehyde (MDA) content, superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities in plasma were assayed by a spectrophotometer. Types I and III collagen were detected by Sirius red polarization and microscopy, and measuered by Image-Pro Plus Version 4.5 for Windows software. RESULTS: GcAE could reduce the lung/body weight ratio of rats exposed to silica, the synthesis of types I and III collagen of the lungs and the level of lipid peroxidation, increase the activities of SOD and GPx. CONCLUSION: GcAE can ameliorate the silica-induced pulmonary fibrosis by increasing the activities of antioxidase and alleviating the damage of lipid peroxidation to the lungs.

[Identification of G6PD gene variants from Hakka population in Guangdong province].

OBJECTIVE: Studying on G6PD polymorphism from Hakka population in Guangdong province. METHODS: Identifying the variants of G6PD gene and determining the frequencies respectively with the use of amplified refractory mutation system(ARMS), polymerase chain reaction-single strand conformation polymorphism(PCR-SSCP) and ABI 3100 DNA sequencing technologies. RESULTS: Mutations of G6PD gene in cDNA 1388 (G-->A), 1376 (G-->T), 95 (A-->G), 392 (G-->T), 1024 (C-->T), 1311 (C-->T) have been found. CONCLUSION: G6PD cDNA 1388 (G-->A), 1376 (G-->T), 95(A--> G), 392 (G-->T), 1024 (C-->T) and 1311 (C-->T) accompanied with intron 11 (93 T-->C) are the common mutations in Chinese population. cDNA 1388 (G-->A), cDNA 1376 (G-->T) are the most popular G6PD gene variants in Hakka population. In this study, no new type of G6PD gene mutation was found in the Hakkas of Guangdong.

Hemoglobinopathy: molecular epidemiological characteristics and health effects on Hakka people in the Meizhou region, southern China.

BACKGROUND: Hemoglobinopathies are the most common inherited diseases in southern China. However, there have been only a few epidemiological studies of hemoglobinopathies in Guangdong province. MATERIALS AND METHODS: Peripheral blood samples were collected from 15299 "healthy" unrelated subjects of dominantly ethnic Hakka in the Meizhou region, on which hemoglobin electrophoresis and routine blood tests were performed. Suspected cases with hemoglobin variants and hereditary persistence of fetal hemoglobin (HPFH) were further characterized by PCR, DNA sequencing, reverse dot blot (RDB) or multiplex ligation-dependent probe amplification (MLPA). In addition, 1743 samples were randomly selected from the 15299 subjects for thalassemia screening, and suspected thalassemia carriers were identified by PCR and RDB. RESULTS: The gene frequency of hemoglobin variants was 0.477% (73/15299). The five main subgroups of the ten hemoglobin variants were Hb E, Hb G-Chinese, Hb Q-Tahiland, Hb New York and Hb J-Bangkok. 277 cases (15.89%, 277/1743) of suspected thalassemia carriers with microcytosis (MCV<82 fl) were found by thalassemia screening, and were tested by a RDB gene chip to reveal a total of 196 mutant chromosomes: including 124 α-thalassemia mutant chromosomes and 72 ß-thalassemia mutant chromosomes. These results give a heterozygote frequency of 11.24% for common α and ß thalassemia in the Hakka population in the Meizhou region. 3 cases of HPFH/δß-thalassemia were found, including 2 cases of Vietnamese HPFH (FPFH-7) and a rare Belgian( G)γ((A)γδß)°-thalassemia identified in Chinese. CONCLUSIONS: Our results provide a detailed prevalence and molecular characterization of hemoglobinopathies in Hakka people of the Meizhou region. The estimated numbers of pregnancies each year in the Meizhou region, in which the fetus would be at risk for ß thalassemia major or intermedia, Bart's hydrops fetalis, and Hb H disease, are 25 (95% CI, 15 to 38), 40 (95% CI, 26 to 57), and 15 (95% CI, 8 to 23), respectively.

[Complex mutations of 1311 C-->T in exon 11 and 93 T-->C in intron 11 in G6PD gene].

OBJECTIVE: To investigate the relationship between complex 1311 mutation of C-->T in exon 11 and 93 T-->C in intron 11 of G6PD gene and the G6PD deficiency. METHODS: Using NBT paper strip method to screen and quantitative NBT method to confirm G6PD deficiency. PCR-SSCP technique was used to find the abnormal exon 11 and the amplification refractory mutation system (ARMS) to identify 1311 mutation, and DNA sequencing to identify the complex mutation at 1311 in exon 11 and 93 in intron 11. RESULTS: Abnormal band in exon 11 was found in 12 cases. DNA sequencing showed that they were 1311 mutation together with 93 mutation. CONCLUSION: This complex mutation may be the cause of reduced activity of G6PD enzyme.