Fatty and lean red meat consumption in China: differential association with Chinese abdominal obesity

AIM

We examined the longitudinal association between red meat (RM) consumption and the risk of abdominal obesity in Chinese adults.

METHODS AND RESULTS

Our data are from 16,822 adults aged 18-75 in the China Health and Nutrition Survey from 1993 to 2011. We assessed RM intake with three 24-h dietary recalls. We defined abdominal obesity as a waist circumference (WC) ≥85 centimeters (cm) for men and ≥80 cm for women. Multilevel mixed-effect regression models showed that men experienced WC increases of 0.74 cm (95% confidence interval [CI]: 0.39-1.09) from a higher total intake of fresh RM and 0.59 cm (95% CI: 0.24-0. 95) from a higher intake of fatty fresh RM but 0.14 cm (95% CI: -0.39 to 0.66) from a higher intake of lean fresh RM in the top quartile versus non-consumers when adjusted for potential confounders. In contrast, after additional adjustment for baseline WC, the odds ratios of abdominal obesity in men were attenuated for total fresh RM (1.25 [95% CI: 1.06-1.47]) and fatty fresh RM (1.22 [95% CI: 1.03-1.44]) but were still not affected by lean fresh RM (0.95 [95% CI: 0.75-1.22]). Women also showed a positive association of fatty fresh RM intake with abdominal obesity.

CONCLUSION

Greater intake of fatty fresh RM was significantly associated with higher WC (men only) and abdominal obesity risk in Chinese adults. The gender-specific differential association of fatty versus lean fresh RM warrants further study.

Trends in dietary fiber intake in Chinese aged 45 years and above, 1991-2011

BACKGROUND/OBJECTIVES

To analyze the time trends in total dietary fiber (DF) intake, DF food sources and total DF intake per 1000 kcal (DF density) in Chinese adults aged 45 years and above in the past 20 years.

SUBJECTS/METHODS

We used the data from the China Health and Nutrition Survey (CHNS) collected in 1991, 1993, 1997, 2000, 2004, 2006, 2009 and 2011. Adults who were aged 45 years and above were included in each round. Water-insoluble DF intake was calculated by substituting the water-insoluble DF content of each food in the Chinese Food Composition Table (FCT) for food intake. Total DF was calculated according to the convert index, which indicates the ratio between total DF and water-insoluble DF for each food group.

RESULTS

The mean daily total DF intake in males was 19.5 g/day in 1991 and 19.4 g/day in 2011. In females, it was 17.5 g/day in 1991 and 17.6 g/day in 2011. DF density increased in both males and females from 2004 to 2011. It was 9.0 g/1000 kcal in males and 9.5 g/1000 kcal in females in 2011. The major food sources of water-insoluble DF were cereals and vegetables. Communities with different levels of urbanization showed different trends in total DF intake: decreased consumption (2.9 g) in residents of low-urbanization communities and increased consumption (3.1 g) in those of high-urbanization communities.

CONCLUSION

The average total DF intake in Chinese adults aged 45 years and above remained at a stable level. DF density increased because of slight decrease in energy intake. More public health messages should be disseminated, especially to the residents of low-urbanization communities, so as to increase their daily DF intake to a level close to the recommended DF intake.

The physical activity transition among adults in China: 1991-2011

Previous studies have linked work, home production, travel activities and inactivity with weight and health outcomes. However, these focused on average physical activity (PA) over time rather than changes in PA and associated sociodemographic and economic factors and urbanicity. Using the 1991-2011 China Health and Nutrition Survey data, we estimated the metabolic equivalent of task hours per week for individuals in occupational, domestic, travel and active leisure domains and sedentary hours per week. We present the distributions among adult men and women (aged 18-60), and use quantile regression models to explore factors associated with these trends. Trend analyses on the distribution of PA show declines along the whole distribution of occupational PA for men and women and domestic PA for women in China. These patterns remain consistent after adjusting for individual- and household-level factors. Controlling for urbanicity mitigated the decrease in occupational PA, particularly for men, but not the decrease in domestic PA. Given China's rapid urbanization and its association with occupational PA declines and the strong time trend in domestic PA, there is a need to invest in interventions and policies that promote PA during leisure and travel times.

Genotyping Toxoplasma gondii from wildlife in Pennsylvania and identification of natural recombinants virulent to mice

Recent studies indicated the predominance of Toxoplasma gondii haplogroup 12 in wildlife in the USA. However, still little is known of the genetic diversity of this parasite circulating in wildlife. In the present study, we tested coyotes (Canis latrans), red foxes (Vulpes vulpes), white-tailed deer (Odocoileus virginianus), and geese (Branta canadensis) from the state of Pennsylvania for T. gondii infection. Antibodies to T. gondii were found in 160 of 367 animals, including 92 (34.5%) of 266 coyotes, 49 (62.0%) of 79 white-tailed deer, 17 (85.0%) of 20 red fox, and two of two Canada geese tested by the modified agglutination test (cut off titer 1:25). Tissues from 105 seropositive animals were bioassayed in mice, and viable T. gondii was isolated from 29 animals, including 10 of 53 coyotes, 11 of 16 foxes, 7 of 49 deer, and one of one goose. DNA isolated from culture-derived tachyzoites of these isolates was characterized initially using multilocus PCR-RFLP markers. Nine genotypes were revealed, including ToxoDB PCR-RFLP #1 (4 isolates), #2 (2 isolates), #3 (4 isolates), #4 (6 isolates), #5 (4 isolates), #54 (1 isolate), #141 (1 isolate), #143 (1 isolate), and #216 (6 isolates), indicating high genetic diversity of T. gondii in wildlife in Pennsylvania. Pathogenicity of six T. gondii isolates (5 of #216 and #141) was determined in outbred Swiss Webster mice. Three of #216 and the #141 isolates were acute virulent to mice, and the other 2 #216 isolates were intermediate virulent. To determine the extent of genetic variation of these as well as a few recently reported virulent isolates from wildlife in North America, intron sequences were generated. Analysis of intron sequences and PCR-RFLP genotyping results indicated that the #216 isolates are likely derived from recombination of the clonal type I and III lineages. To determine if T. gondii virulence can be predicted by typing, we genotyped a collection of strains using PCR-RFLP markers for polymorphic genes ROP5, ROP16, ROP18 and GRA15, which are known to interact with host immune response. The results showed that there is an association of genotypes of ROP5 and ROP18 with mouse-virulence, however, additional gene(s) may also contribute to virulence in distinct T. gondii genotypes.

Construction and application of double-transfected cells expressing the human transporter P-glycoprotein and cytochrome P450 3A4

Intestinal P-glycoprotein (P-gp) and cytochrome P450 (CYP) enzymes are known to influence oral bioavailabilities of drugs. Recombinant plasmids pcDNA3.1/Hypgro/CYP3A4 were transfected into MDCK and MDCK-MDR1 cells to construct the single-transfected cell line MDCK-CYP3A4 and double-transfected cell line MDCK-MDR1/CYP3A4. The expression of CYP3A4 in the double-transfected cell line was determined by Western blot and its activity was detected by the metabolism assays of three substrates of CYP3A4, which were 7-benzyloxy-4-trifluoro-methylcoumarin (BFC), testosterone and midazolam. In addition, the selection of monoclones with high CYP3A4 activities in the single-tranfected cell line was performed by the P450 Glo CYP3A4 assay. Through MTT assay, the interaction between P-gp and CYP3A4 was preliminarily determined based on the changes of IC50 values. The results showed that paclitaxel detoxified in the single-transfected MDCK-MDR1 cell because of P-gp efflux. And it was also less toxic in the single-transfected CYP3A4 cell line due to the metabolism by CYP3A4. In the double-transfected MDCK-MDR1/CYP3A4 cell line, the toxicity decreased dramatically because of the interplay between P-gp and CYP3A4. Therefore, the cell model could be applied to study the toxicity and detoxification of chemicals due to the metabolism by CYP3A4 and the efflux through P-gp.

ROS1 fusions in Chinese patients with non-small-cell lung cancer

BACKGROUND

To determine the prevalence and clinicopathological features of ROS1 fusions in Chinese patients with non-small-cell lung cancer (NSCLC).

METHODS

Formalin-fixed and paraffin-embedded (FFPE) tissue sections from 392 patients with NSCLC were screened for ROS1 fusions by multiplex RT-PCR and all ROS1 fusions were validated by direct sequencing. The relationship between ROS1 fusions and clinicopathological features and the prognostic effect of the ROS1 fusion status on survival were analyzed.

RESULTS

In this study, 8 of 392 (2.0%) evaluable samples were found to harbor ROS1 fusions. Of the ROS1-positive patients, seven presented with adenocarcinoma, and one with adenosquamous carcinoma. The ratio of female to male and never smoker to smokers in a ROS1 fusion-positive group was 5:3. There was no statistically significant difference in age, sex, smoking history, histological type and pathological stage between ROS1 fusion-positive and ROS1 fusion-negative patients. ROS1 fusion-negative patients had a significantly longer survival when compared with ROS1 fusion-positive patients (P = 0.041). Lower pathological stage, younger age and ROS1 fusion-negative status were significantly associated with better prognosis on multivariate analysis.

CONCLUSIONS

ROS1 fusions occurred in ∼2.0% of Chinese patients with NSCLC and had no specific clinicopathological feature. ROS1 fusion-negative patients may have a better survival than ROS1 fusion-positive patients.

Guanosine promotes proliferation of neural stem cells through cAMP-CREB pathway

In previous studies, we have found that extracellular guanosine can stimulate endogenous progenitor/stem cell proliferation in the spinal cord following chronic injury and in the subventricular zone of the brains of rats afflicted with Parkinson's Disease. In this study, using neural stem cells isolated from one-day old rats, we found that guanosine could stimulate neural stem cell proliferation, and that the proliferation was not due to the guanosine metabolism mechanism since guanine, which is interconverted by an ecto-purine nucleoside phosphorylase from guanosine, has no stimulating effect on the proliferation of neural stem cells. We determined that second messenger cAMP was involved in the pathway as results showed that 100 microM guanosine stimulated cAMP accumulation. Using western blot analysis, we found that 100 microM guanosine can activate the phosphorylation of CREB without changing the total amount of CREB. In conclusion, guanosine can stimulate neural stem cell proliferation, and the cAMP-CREB pathway is involved in this biological effect.

Construction of a primary DNA fingerprint database for cotton cultivars

Forty core primers were used to construct a DNA fingerprint database of 132 cotton species based on multiplex fluorescence detection technology. A high first successful ratio of 99.04% was demonstrated with tetraplex polymerase chain reaction. Forty primer pairs amplified a total of 262 genotypes among 132 species, with an average of 6.55 per primer and values of polymorphism information content varying from 0.340 to 0.882. Conflicting DNA homozygous ratios were found in various species. The highest DNA homozygous ratio was found in landrace standard cultivars, which had an 81.46% DNA homozygous ratio. The lowest occurred in a group of 2010 leading cultivars with a homozygous ratio of 63.04%. Genetic diversity of the 132 species was briefly analyzed using unweighted pair-group method with arithmetic means.

Occurrence, isolation, and genetic characterization of Toxoplasma gondii from white-tailed deer (Odocoileus virginianus) in New Jersey

The ingestion of uncooked infected white-tailed deer (WTD) tissues can transmit Toxoplasma gondii infection to humans and mesocarnivores, including cats. In the present study, we tested 264 WTD from New Jersey for T. gondii infection during the 2011-2012 hunting season. Serum samples were tested for antibodies to T. gondii by the modified agglutination test (cutoff titer, 25); 76 (28.7%) of 264 WTD were seropositive. Heart muscle samples from 64 seropositive WTD were digested in pepsin, and the digests were bioassayed for the isolation of T. gondii . Viable T. gondii was isolated in mice from the myocardium of 9 WTD; tachyzoites from infected mouse tissues were further propagated in cell culture. One of the 9 strains was highly virulent for outbred Swiss Webster mice. The DNA isolated from culture-derived tachyzoites of these 9 T. gondii isolates was characterized using 11 PCR-RFLP markers (SAG1, 5'- and 3'-SAG2, alt.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico). Six genotypes were found, including ToxoDB genotype no. 2 (Type III), no. 3 (Type II variant), no. 4 (Type 12), no. 216, no. 220, and no. 221. The last 2 were new genotypes that were reported for the first time. This is the first report of T. gondii infection in deer from this region of the United States.

Genetic characterization of viable Toxoplasma gondii isolates from stray dogs from Giza, Egypt

Stray dogs are considered as sentinels in the epidemiology of Toxoplasma gondii because they are carnivores and eat variety of foods, including garbage. In the present study, tissues and sera of 51 stray dogs (Canis familiaris) from Giza, Egypt were examined for T. gondii infection. Sera were examined for antibodies to T. gondii by the modified agglutination test (MAT); 50 of 51 (98%) were seropositive with titers of 20 in four, 40 in four, 80 in one, 100 in eight, 200 in 17, 400 in 11, 800 or higher in five. Hearts of 43 seropositive dogs were bioassayed in mice. Viable T. gondii was isolated from 22 dogs; these isolates were designated TgDogEg1 to TgDogEg22. DNA isolated from cell culture derived tachyzoites of 22 isolates was genotyped using 10 PCR-restriction fragment length polymorphism markers (SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico). The results revealed three genotypes and one mixed infection. The three genotypes are ToxoDB PCR-RFLP #2 (type III, four isolates), #3 (type II variant, 11 isolates), #20 (six isolates), 1 mixed infection. These results revealed the dominance of clonal type II, III and ToxoDB #20 lineages of T. gondii in stray dogs from Giza, Egypt.

Molecular genotyping of Toxoplasma gondii from Central and South America revealed high diversity within and between populations

Recent population studies revealed that a few major clonal lineages of Toxoplasma gondii dominate in different geographical regions. The Type II and III lineages are widespread in all continents and dominate in Europe, Africa and North America. In addition, the type 12 lineage is the most common type in wildlife in North America, the Africa 1 and 3 are among the major types in Africa, and ToxoDB PCR-RFLP #9 is the major type in China. Overall the T. gondii strains are more diverse in South America than any other regions. Here, we analyzed 164 T. gondii isolates from three countries in Central America (Guatemala, Nicaragua, Costa Rica), from one country in Caribbean (Grenada) and five countries from South America (Venezuela, Colombia, Peru, Chile, and Argentina). The multilocous polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) based genotyping of 11 polymorphic markers (SAG1, SAG2, alt.SAG2, SAG3, BTUB, GRA6, L358, PK1, C22-8, C29-2 and Apico) were applied to 148 free-range chicken (Gallus domesticus) isolates and 16 isolates from domestic cats (Felis catus) in Colombia; 42 genotypes were identified. Linkage disequilibrium analysis indicated more frequent genetic recombination in populations of Nicaragua and Colombia, and to a lesser degree in populations of Costa Rica and Argentina. Bayesian structural analysis identified at least three genetic clusters, and phylogenetic network analysis identified four major groups. The ToxoDB PCR-RFLP #7, Type III and II were major lineages identified from Central and South America, with high frequencies of the closely related ToxoDB PCR-RFLP #7 and Type III lineages. Taken together, this study revealed high diversity within and between T. gondii populations in Central and South America, and the dominance of Type III and its closely related ToxoDB PCR-RFLP #7 lineages.