Defu Ma

Coffee consumption and risk of colorectal cancer: a meta-analysis of observational studies

OBJECTIVE Separate meta-analyses based on case-control and cohort studies have reported different results on the relationship between coffee consumption and colorectal cancer risk. To clarify the effect of coffee intake on colorectal cancer risk, we performed a meta-analysis based on both case-control and cohort studies. DESIGN Review study. SETTING We identified case-control and cohort studies related to coffee consumption and colorectal cancer risk listed on MEDLINE, the Cochrane Controlled Trials Register, EMBASE, Science Citation Index and PubMed (until May 2011). SUBJECTS Research literature on the relationship between coffee consumption and colorectal cancer risk. RESULTS Twenty-five case-control (15 522 cases) and sixteen cohort studies (10 443 cases) were included in the meta-analysis. Comparing the highest v. the lowest/non category of coffee consumption, the combined results from case-control studies showed a significant relationship with colorectal cancer (OR = 0·85, 95 % CI 0·75, 0·97) and colon cancer (OR = 0·79, 95 % CI 0·67, 0·95), but not rectal cancer (OR = 0·95, 95 % CI 0·79, 1·15). For cohort studies, there was a slight suggestion of an inverse association with colorectal cancer (relative ratio = 0·94; 95 % CI 0·88, 1·01) and colon cancer (OR = 0·93, 95 % CI 0·86, 1·01), rather than rectal cancer (OR = 0·98, 95 % CI 0·88, 1·09). In subgroup analyses using case-control studies, significant inverse associations were found in females for colorectal cancer and in Europe for colorectal and colon cancer, while the subgroup analyses of cohort studies found that coffee drinks substantially decreased risk of colon cancer only in Asian women. CONCLUSIONS Results from case-control studies suggest coffee consumption can significantly decrease the risks of colorectal cancer and colon cancer, especially in Europe and for females.

Pre-pregnancy BMI, gestational weight gain and postpartum weight retention: a meta-analysis of observational studies

OBJECTIVE To determine the association of gestational weight gain (GWG) or pre-pregnancy BMI with postpartum weight retention (PPWR). DESIGN Meta-analysis. SETTING PubMed, Cochrane Controlled Trials Register, EMBASE, Science Citation Index Expanded, Current Contents Connects and Biosis Previews were used to search articles. SUBJECTS Publications that described the influence of pre-pregnancy BMI or GWG on PPWR. RESULTS Seventeen studies that satisfied the eligibility criteria were included in the analyses. Women with inadequate and excessive GWG had significantly lower mean PPWR of -2·14 kg (95 % CI -2·43, -1·85 kg) and higher PPWR of 3·21 kg (95 % CI 2·79, 3·62 kg), respectively, than women with adequate GWG. When postpartum time spans were stratified into 1-3 months, 3-6 months, 6-12 months, 12-36 months and ≥15 years, the association between inadequate GWG and PPWR faded over time and became insignificant (-1·42 kg; 95 % CI -3·08, 0·24 kg) after ≥15 years. However, PPWR in women with excess GWG exhibited a U-shaped trend; that is, a decline during the early postpartum time span (year 1) and then an increase in the following period. Meta-analysis of qualitative studies showed a significant relationship between excessive GWG and higher PPWR risk (OR=2·08; 95 % CI 1·60, 2·70). Moreover, meta-analysis of pre-pregnancy BMI on PPWR indicated that mean PPWR decreased with increasing BMI group. CONCLUSIONS These findings suggest that GWG, rather than pre-pregnancy BMI, determines the shorter- or longer-term PPWR.

(±)Equol inhibits invasion in prostate cancer DU145 cells possibly via down-regulation of matrix metalloproteinase-9, matrix metalloproteinase-2 and urokinase-type plasminogen activator by antioxidant activity.

Exposure to soy isoflavones has been associated with low mortality of prostate cancer. In this study, we examined the effects of (±)equol and two representative isoflavones, daidzein and genistein, on migration and invasion in human prostate cancer DU145 cells. First of all, the three regents did not show significant growth inhibitive effect in DU145 cells until the treatments last for 72 h. Treatment with 5 µM, 10 µM, 50 µM (±)equol, 0.5 µM, 1 µM, 5 µM daidzein and genistein for 24 h decreased cell migration and invasion significantly. (±)equol activated phosphatase and tensin homologue deleted on chromosome ten at protein level but not mRNA level, which activated antioxidants, including superoxide dismutase and nuclear factor (erythroid-derived 2)-like 2. A reduction of malondialdehyde concentration, the product of lipid per-oxidation, was observed as well. Moreover, matrix metalloproteinase-2, matrix metalloproteinase-9, and urokinase-type plasminogen activator, the crucial members in metastasis, were down-regulated. Overall, our data indicate that (±)equol, daidzein and genistein may have significant anti-invasion effect in DU145 cells (in vitro). The effects induced by (±)equol may relate to its anti-oxidant effect mediated by phosphatase and tensin homologue deleted on chromosome ten.

A novel 3p22.3 gene CMTM7 represses oncogenic EGFR signaling and inhibits cancer cell growth

Deletion of 3p12-22 is frequent in multiple cancer types, indicating the presence of critical tumor-suppressor genes (TSGs) at this region. We studied a novel candidate TSG, CMTM7, located at the 3p22.3 CMTM-gene cluster, for its tumor-suppressive functions and related mechanisms. The three CMTM genes, CMTM6, 7 and 8, are broadly expressed in human normal adult tissues and normal epithelial cell lines. Only CMTM7 is frequently silenced or downregulated in esophageal and nasopharyngeal cell lines, but uncommon in other carcinoma cell lines. Immunostaining of tissue microarrays for CMTM7 protein showed its downregulation or absence in esophageal, gastric, pancreatic, liver, lung and cervix tumor tissues. Promoter CpG methylation and loss of heterozygosity were both found contributing to CMTM7 downregulation. Ectopic expression of CMTM7 in carcinoma cells inhibits cell proliferation, motility and tumor formation in nude mice, but not in immortalized normal cells, suggesting a tumor inhibitory role of CMTM7. The tumor-suppressive function of CMTM7 is associated with its role in G1/S cell cycle arrest, through upregulating p27 and downregulating cyclin-dependent kinase 2 (CDK2) and 6 (CDK6). Moreover, CMTM7 could promote epidermal growth factor receptor (EGFR) internalization, and further suppress AKT signaling pathway. Thus, our findings suggest that CMTM7 is a novel 3p22 tumor suppressor regulating G1/S transition and EGFR/AKT signaling during tumor pathogenesis.

The CKLF1-C19 peptide attenuates allergic lung inflammation by inhibiting CCR3- and CCR4-mediated chemotaxis in a mouse model of asthma.

To cite this article: Tian L, Li W, Wang J, Zhang Y, Zheng Y, Qi H, Guo X, Zhang Y, Ma D, Shen H, Wang Y. The CKLF1‐C19 peptide attenuates allergic lung inflammation by inhibiting CCR3‐ and CCR4‐mediated chemotaxis in a mouse model of asthma. Allergy 2011; 66: 287–297.

Growth and Development in Chinese Pre-Schoolers with Picky Eating Behaviour: A Cross-Sectional Study

Objective To explore the associations between picky eating behaviour and pre-schoolers’ growth and development. Corresponding potential mechanisms, such as nutrient and food subgroup intake, as well as micronutrients in the blood, will be considered. Methods Picky eating behaviour was present if it was reported by parents. From various areas of China, 937 healthy children of 3-7 years old were recruited using a multi-stage stratified cluster sampling method. Children and their mothers’ socio-demographic information and children’s anthropometry, intelligence, blood samples, one 24-hour dietary intake record and food frequency questionnaire were collected. Z-scores and intelligence tests were used to evaluate growth and development (cognitive development). Multilevel models were employed to verify the associations between picky eating behaviour and growth and development. Results The prevalence of picky eating as reported by parents was 54% in pre-schoolers. Compared with the non-picky eaters, weight for age in picky eaters was 0.14 z-score (95% CI: -0.25, -0.02; p = 0.017) lower while no significant difference was found in intelligence (p > 0.05). Picky eating behaviour lasting over two years was associated with lower weight for age, as was nit-picking meat (the prevalence from parents’ perception was 23% in picky eaters) (p < 0.05). Picky eaters consumed fewer cereals, vegetables, and fish (p < 0.05), and had a lower dietary intake of protein, dietary fibre, iron, and zinc (p < 0.05). There were no differences in the concentrations of essential minerals in whole blood (p > 0.05). Conclusions Picky eating behaviour is reported by parents in half of the Chinese pre-schoolers, which is negatively associated with growth (weight for age). Lower protein and dietary fibre as well as lower iron and zinc intakes were associated with picky eating as were lower intakes of vegetables, fish and cereals.

Association between gestational weight gain according to prepregnancy body mass index and short postpartum weight retention in postpartum women

BACKGROUND & AIMS This study aims to assess the relationship among prepregnancy body mass index, gestational weight gain, and postpartum weight retention, and to clarify the predictors of the amount of weight retained by Chinese women after pregnancy. METHODS The multistage stratified random sampling was used in the cross-sectional study. RESULTS The subjects included 1643 women. Mean gestational weight gain was 15.9 kg and mean postpartum weight retention was 5.1 kg. 43.2% of women gained excessive gestational weight gain and 53.3% of women gained 5 kg or more postpartum weight retention. In addition, the proportions of underweight women with inadequate weight gain and overweight women with excessive weight gain were 24.2% and 52.3%, respectively. Logistic regression analysis showed that the adjusted OR of excessive gestational weight gain was 1.74 (95% CI: 1.09-2.79) in overweight women compared with normal weight women. The postpartum weight retention and the proportion of women with postpartum weight retention of 5 kg or more were significantly higher in the excessive gestational weight gain women than in the adequate gestational weight gain women in all three body mass index groups. The adjusted OR of a weight increase of 5 kg or more was at least 1.90 for underweight, normal weight, and overweight women with a gestational weight gain above the recommended amount compared with those with a gestational weight gain within the recommended amount. CONCLUSIONS Gestational weight gain above the recommended amount increases the risk of postpartum weight retention in all body mass index groups.

Serum lipid-improving effect of soyabean β-conglycinin in hyperlipidaemic menopausal women.

To evaluate the effect of treatment with β-conglycinin, a major soyabean protein, on blood lipids in menopausal women, we recruited 100 hyperlipidaemic women aged 40-60 years old. Participants were randomly allocated to three groups: placebo group (n 34, four casein tablets/d); low dose group (n 33, four tablets containing 2·3 g β-conglycinin/d); high-dose group (n 33, eight tablets containing 4·6 g β-conglycinin/d). The mean serum TAG concentration was significantly reduced after 6 and 12 weeks of β-conglycinin intervention by 0·44 (sd 0·20) and 0·78 (sd 1·03) mmol/l in the low-dose group, and by 0·46 (sd 0·17) and 1·25 (sd 1·06) mmol/l in the high-dose group, respectively. One-way ANOVA revealed that serum TAG concentrations in the low-dose and high-dose groups were significantly lowered compared with the placebo group at weeks 6 and 12 (P< 0·05). The low dose and high dose consumptions of β-conglycinin significantly decreased the LDL-cholesterol concentration by 0·46 (sd 0·72) and 0·52 (sd 0·97) mmol/l at week 12, respectively (P< 0·05). Compared with the changes from baseline in the placebo group, apoB and NEFA were significantly lowered in both the low-dose and high-dose β-conglycinin groups (P< 0·05). In conclusion, the results suggest that β-conglycinin intake significantly decreases serum TAG and LDL-cholesterol levels.

Current situation of clinical trials in Beijing, China

PURPOSE This study investigated the current quality of clinical trials conducted in China. METHODS Questionnaires were administered to medical doctors belonging to institutes affiliated to Peking University in Beijing, China. The delivery and collection of questionnaires were conducted by a research team from China. Analysis and evaluation were conducted by research teams from both China and Japan. RESULTS A total of 145 questionnaires were administered and 117 respondents included the name of the medical institution to which they belonged. A total of 56.3% of the respondents participated in audit and inspection by institutes and 50.5% of the respondents reported receipt of the audit findings. A further 23.6% participated in audits and inspections performed by an external authority and 20.2% reported the receipt of the audit findings. CONCLUSION Our research suggests that clinical trials in Beijing are well conducted and are monitored by both institutions and external authorities.

Isoflavone intake inhibits the development of 7,12-dimethylbenz(a)anthracene(DMBA)-induced mammary tumors in normal and ovariectomized rats

To determine the associations between isoflavone (49.72% genistin, 5.32% daidzin, 34.54% glycitin) and breast cancer risk, 150 rats were given 5 mg 7,12-dimethylbenz(a)anthracene and half of them were ovariectomized. Then normal rats and ovariectomized rats were divided into 5 groups: control group, isoflavone high (HI), middle (MI), or low (LI) dose group consuming 100, 500, or 1000 mg isoflavones/kg diet, estrogen group (2.5 mg stilboestrol/kg diet). After 24 weeks, tumor incidences were 73% in control group, 7% in HI, 7% in MI, 27% in LI, and 80% in estrogen group for normal rats; 60% in control group, 13% in HI, 7% in MI, 13% in LI, and 73% in estrogen group for ovariectomized rats. Isoflavone treatment decreased tumor incidence and mean tumor number per rat and increased mean latent period compared with those in control group and estrogen group group significantly (p<0.05). The mRNA and protein expression of estrogen receptor β were significantly higher in isoflavone treatment groups than those in control group group. Moreover, isoflavone treatment significantly decreased 8-hydroxydeoxyguanosine content and increased superoxide dismutase level in normal rats and decreased malondialdehyde concentrations in ovariectomized rats compared with control group. In conclusions, isoflavone intake significantly inhibited the development of premenopausal and postmenopausal mammary tumors.