Fine-mapping of genes determining extrafusal fiber properties in murine soleus muscle

Muscle fiber cross-sectional area (CSA) and proportion of different fiber types are important determinants of muscle function and overall metabolism. Genetic variation plays a substantial role in phenotypic variation of these traits; however, the underlying genes remain poorly understood. This study aimed to map quantitative trait loci (QTL) affecting differences in soleus muscle fiber traits between the LG/J and SM/J mouse strains. Fiber number, CSA, and proportion of oxidative type I fibers were assessed in the soleus of 334 genotyped female and male mice of the F₃₄ generation of advanced intercross lines (AIL) derived from the LG/J and SM/J strains. To increase the QTL detection power, these data were combined with 94 soleus samples from the F₂ intercross of the same strains. Transcriptome of the soleus muscle of LG/J and SM/J females was analyzed by microarray. Genome-wide association analysis mapped four QTL (genome-wide P < 0.05) affecting the properties of muscle fibers to chromosome 2, 3, 4, and 11. A 1.5-LOD QTL support interval ranged between 2.36 and 4.67 Mb. On the basis of the genomic sequence information and functional and transcriptome data, we identified candidate genes for each of these QTL. The combination of analyses in F₂ and F₃₄ AIL populations with transcriptome and genomic sequence data in the parental strains is an effective strategy for refining QTL and nomination of the candidate genes.

The effect of immunoglobulin treatment for hemolysis on the incidence of necrotizing enterocolitis - a meta-analysis

OBJECTIVE

The application of intravenous immune globulin (IVIG) has been recommended for treating hemolysis in neonates for several years. But in clinical work, more than one study reported that IVIG treatment maybe increased the risk of NEC in hemolytic patients. In light of this situation, we performed this meta-analysis.

MATERIALS AND METHODS

We searched in PubMed, Embase, Cochrane databases for English references, and in Wanfang, VIP, Cnki databases for Chinese references (all last launched on 2015/12/18). Ultimately, 5 studies (Including 4 Chinese articles) were incorporated into this meta-analysis. Odds ratio (OR) and weighted mean difference (WMD) were calculated using a random-effects or fixed-effects model, depending on the data type and heterogeneity of the included studies.

RESULTS

(1) Baseline data including gestational age, gender and TBil between IVIG and control groups were compared in hemolytic infants, and showed no significance. (2) With respect to possible inducement of NEC, SGA and formula feeding were found no significance between IVIG and control groups. In contrast, birth weight was found significantly different between the two groups (WMD = 33.35; 95% CI, 20.70-46.01; p < 0.00001). (3) Regarding the incidence of NEC and mortality, the result showed that there was a significant difference between the IVIG and the control groups in the risk of NEC (OR: 4.53; 95% CI, 2.34-8.79; p < 0.00001).

CONCLUSIONS

Our results indicate that IVIG treatment for hemolysis may increase the risk of NEC in infants. But it does not increase the risk of final mortality.

Lunch-time food choices in preschoolers: Relationships between absolute and relative intakes of different food categories, and appetitive characteristics and weight

Children's appetitive characteristics measured by parent-report questionnaires are reliably associated with body weight, as well as behavioral tests of appetite, but relatively little is known about relationships with food choice. As part of a larger preloading study, we served 4-5year olds from primary school classes five school lunches at which they were presented with the same standardized multi-item meal. Parents completed Child Eating Behavior Questionnaire (CEBQ) sub-scales assessing satiety responsiveness (CEBQ-SR), food responsiveness (CEBQ-FR) and enjoyment of food (CEBQ-EF), and children were weighed and measured. Despite differing preload conditions, children showed remarkable consistency of intake patterns across all five meals with day-to-day intra-class correlations in absolute and percentage intake of each food category ranging from 0.78 to 0.91. Higher CEBQ-SR was associated with lower mean intake of all food categories across all five meals, with the weakest association apparent for snack foods. Higher CEBQ-FR was associated with higher intake of white bread and fruits and vegetables, and higher CEBQ-EF was associated with greater intake of all categories, with the strongest association apparent for white bread. Analyses of intake of each food group as a percentage of total intake, treated here as an index of the child's choice to consume relatively more or relatively less of each different food category when composing their total lunch-time meal, further suggested that children who were higher in CEBQ-SR ate relatively more snack foods and relatively less fruits and vegetables, while children with higher CEBQ-EF ate relatively less snack foods and relatively more white bread. Higher absolute intakes of white bread and snack foods were associated with higher BMI z score. CEBQ sub-scale associations with food intake variables were largely unchanged by controlling for daily metabolic needs. However, descriptive comparisons of lunch intakes with expected amounts based on metabolic needs suggested that overweight/obese boys were at particularly high risk of overeating. Parents' reports of children's appetitive characteristics on the CEBQ are associated with differential patterns of food choice as indexed by absolute and relative intake of various food categories assessed on multiple occasions in a naturalistic, school-based setting, without parents present.

Lentiginous phenotypes caused by diverse pathogenic genes (SASH1 and PTPN11): clinical and molecular discrimination

Pathogenic mutations in genes (SASH1 and PTPN11) can cause a rare genetic disorder associated with pigmentation defects and the well-known LEOPARD syndrome, respectively. Both conditions presented with lentiginous phenotypes. The aim of this study was to arrive at definite diagnoses of three Chinese boys with clinically suspected lentigines-related syndromes. ADAR1, ABCB6, SASH1 and PTPN11 were candidate genes for mutational screening. Sanger sequencing was performed to identify the mutations, whereas bioinformatic analysis was used to predict the pathogenicity of novel missense mutations. Two novel mutations c.1537A>C (p.Ser513Arg) and 1527_1530dupAAGT (p.Leu511Lysfs*21) in SASH1 and a common p.Thr468Met mutation in PTPN11 were detected in three pediatric patients with lentiginous phenotypes, respectively. Comparisons between clinical presentations showed that SASH1-related phenotypes can exhibit hyper- and hypopigmentation on the trunk and extremities, similar to dyschromatosis, while scattered café au-lait spots usually appeared in PTPN11-related LEOPARD syndrome. Furthermore, the similarity in the clinical presentations of Peutz-Jeghers syndrome, Laugier-Hunziker syndrome, xeroderma pigmentosum, neurofibromatosis type I, suggesting that these conditions should be added into the differential diagnoses of lentiginous phenotypes.

Interaction between mDia1 and ROCK in Rho-induced migration and adhesion of human dental pulp cells

AIM

To investigate the effects of mammalian homologue of Drosophila diaphanous-1(mDia1) and Rho-associated coiled-coil-containing protein kinase (ROCK) on the migration and adhesion of dental pulp cells (DPCs).

METHODOLOGY

Lysophosphatidic acid (LPA) was used to activate Rho signalling. mDia1 and ROCK were inhibited by short interfering RNA and the specific inhibitor, Y-27632, respectively. The migration of DPCs was assessed using the transwell migration assay and scratch test. Formation of cytoskeleton and focal adhesions(FAs) was observed by confocal laser scanning microscopy. Cell adhesion and spreading assays were performed. Phosphorylation of focal adhesion kinase (FAK) and paxillin was detected by Western blotting, and the bands were analysed using Adobe Photoshop CS5 software. All experiments were performed at least three times, and data were analysed with one-way anova and a post hoc test.

RESULTS

LPA-triggered activation of Rho and inhibition of ROCK significantly increased the cell migration rate. Cell migration was inhibited by silencing mDia1. mDia1 silencing and ROCK inhibition suppressed the LPA-induced formation of the cytoskeleton, FA and phosphorylation of FAK and paxillin. Inhibition of ROCK or mDia1 facilitated early cell adhesion and spreading; by contrast, the combined inhibition of ROCK and mDia1 neutralized these effects.

CONCLUSIONS

mDia1 promoted RhoA-induced migration of DPCs, but ROCK had an opposite effect. Both mDia1 and ROCK participated in cytoskeleton formation and adhesion of DPCs. The interactions between mDia1 and ROCK might influence dental pulp repair by determining the migration and adhesion of DPCs.

Gingival fibroblasts resist apoptosis in response to oxidative stress in a model of periodontal diseases

Periodontal diseases are classified as inflammation affecting the supporting tissue of teeth, which eventually leads to tooth loss. Mild reversible gingivitis and severe irreversible periodontitis are the most common periodontal diseases. Periodontal pathogens initiate the diseases. The bacterial toxin, lipopolysaccharide (LPS), triggers the inflammatory response and leads to oxidative stress. However, the progress of oxidative stress in periodontal diseases is unknown. The purpose of this study is to examine oxidative stress and cell damage in gingivitis and periodontitis. Our results showed that LPS increases reactive oxygen species (ROS) accumulation in gingival fibroblast (GF). However, oxidative stress resulting from excessive ROS did not influence DNA damage and cell apoptosis within 24 h. The mechanism may be related to the increased expression of DNA repair genes, Ogg1, Neil1 and Rad50. Detection of apoptosis-related proteins also showed anti-apoptotic effects and pro-apoptotic effects were balanced. The earliest damage appeared in DNA when increased γH2AX, an early biomarker for DNA damage, was detected in the LPS group after 48 h. Later, when recurrent inflammation persisted, 8-OHdG, a biomarker for oxidative stress was much higher in periodontitis model compared to the control in vivo. Staining of 8-OHdG in human periodontitis specimens confirmed the results. Furthermore, TUNEL staining of apoptotic cells indicated that the periodontitis model induced more cell apoptosis in gingival tissue. This suggested GF could resist early and acute inflammation (gingivitis), which was regarded as reversible, but recurrent and chronic inflammation (periodontitis) led to permanent cell damage and death.

Current state of allocation of oral health human resources in northern China and future needs

OBJECTIVE

The aim of the present investigation was to describe the distribution, structure and allocation of oral health services personnel, evaluate oral health service capacity and predict the needs for oral health services in northern China over the coming 10 years.

METHODS

The questionnaires were sent to all the dental medical institutions included in this study directly from the Sanitation Bureau and the Health Supervision Station. All the institutions and dental personnel were asked to fill out the questionnaires, and then, the questionnaires were collected through postal service and email.

RESULTS

In Liaoning Province, which is in northern China, there are a total of 5617 dentists in total, 87.8% of whom are located in urban areas. Dentists in rural areas were found to be less educated and specialized. The ratio of dentists to nurses to technicians was about 6:2:1, and the ratio of dentists to total population was 1:7682. It was predicted that, in 2020, the number of dentists could reach 13 207. This would meet the area's needs for oral health services.

CONCLUSION

Currently, in northern China, the oral health infrastructure suffers from an insufficient number of dental professionals, disproportionate distribution and inappropriate structure. To improve social equity, it is necessary to adjust the distribution of dental personnel capable of performing for oral health services.