FoxP3+ Regulatory T Cells Attenuate Experimental Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) results from severe intestinal inflammation in premature infants. FoxP3⁺ regulatory T cells (Tregs) are central to gut homeostasis. While Treg proportions are significantly reduced in the ileums of premature infants with NEC, it is unknown whether they play a critical function in preventing NEC. This study investigated Treg development in newborn rat pups and their role in experimental NEC induction. Utilizing an established rat model of experimental NEC, the ontogeny of T cells and Tregs in newborn pups was characterized by flow cytometry. To investigate the functions of Tregs, newborn pups were given Tregs harvested from adult rats prior to NEC induction to assess clinical improvement and mechanisms of immune regulation. The results revealed that there were few Treg numbers in the terminal ileums of newborn rats and 8-fold reduction after NEC. Adoptive transfer of Tregs significantly improved weight loss, survival from 53% to 88%, and NEC incidence from 87% to 35%. The Tregs modulated the immune response as manifested in reduced CD80 expression on antigen presenting cells and decreased T cell activation within the mesenteric lymph nodes. These findings suggest that while Tregs are present in the intestines, their numbers might be insufficient to dampen the excessive inflammatory state in NEC. Adoptive transfer of Tregs attenuates the severity of NEC by limiting the immune response. Strategies to enhance Tregs have a therapeutic potential in controlling the development of NEC.     

Mini-Incision versus Standard Incision Total Hip Arthroplasty Regarding Surgical Outcomes: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Purpose

It remains controversial whether mini-incision (MI) benefits patients in total hip arthroplasty (THA). We performed a meta-analysis of randomized controlled trials (RCTs) to assess the effects of MI on surgical and functional outcomes in THA patients.

Methods

A systematic electronic literature search (up to May 2013) was conducted to identify RCTs comparing MI with standard incision (SI) THA. The primary outcome measures were surgical and functional outcomes. According to the surgical approach taken, MI THA patients were divided into four subgroups for sub-group meta-analysis. Standardized mean differences (SMDs) or risk differences (RDs) with accompanying 95% confidence intervals (CIs) were calculated and pooled using a fixed-effect or random-effect model according to the heterogeneity.

Results

A total of 14 RCTs involving THA 1,174 patients met the inclusion criteria. The trials were medium risk of bias. The overall meta-analysis showed MI THA reduced total blood loss (95% CI, -201.83 to -21.18; p=.02) and length of hospital stay ( 95% CI, -0.67 to -0.08; p=.01) with significant heterogeneity. However, subgroup meta-analysis revealed posterior MI THA had perioperative advantages of reduced surgical duration ( 95% CI, -8.45 to -2.67; P<.001), less blood loss ( 95% CI, -107.20 to -1.73; P=.04) and shorter hospital stay ( 95% CI, -0.74 to -0.06; p=.002) with low heterogeneity. There were no significant differences between MI and SI THA groups in term of pain medication dose, functional outcome (HHS), radiological outcome or complications (P>.05, respectively).

Conclusions

Although no definite overall conclusion can be arrived at on whether MI THA is superior to SI THA, posterior MI THA clearly result in a significant decrease in surgical duration, blood loss and hospital stay. It seems to be a safe minimally invasive surgical procedure without increasing the risk of component malposition or complications.     

A Country-Wide Study of Spoligotype and Drug Resistance Characteristics of Mycobacterium tuberculosis Isolates from Children in China

Background

Tuberculosis (TB) is still a big threat to human health, especially in children. However, an isolation of Mycobacterium tuberculosis culture from pediatric cases remains a challenge. In order to provide some scientific basis for children TB control, we investigated the genotyping and drug resistance characteristics of M. tuberculosis isolates from pediatric cases in China.

Methodology/Principal Findings

In this study, a total of 440 strains including 90 from children (<15 years), 159 from adolescents (15–18 years) and 191 from adults (>18 years) isolated in 25 provinces across China were subjected to spoligotyping and drug susceptibility testing. As a result, Beijing family strains were shown to remain predominant in China (85.6%, 81.1% and 75.4% in three above groups, respectively), especially among new children cases (91.0% vs. 69.6% in previously treated cases, P = 0.03). The prevalence of the Beijing genotype isolates was higher in northern and central China in the total collection (85.1% in northern and 83.9% in central vs. 61.6% in southern China, P<0.001) and a similar trend was seen in all three age groups (P = 0.708, <0.001 and 0.025, respectively). In adolescents, the frequencies of isoniazid (INH)-resistant and ethambutol (EMB)-resistant isolates were significantly higher among Beijing strains compared to non-Beijing genotype strains (P = 0.028 for INH and P = 0.027 for EMB). Furthermore, strong association was observed between resistance to rifampicine (RIF), streptomycin (STR) and multidrug resistance (MDR) among Beijing compared to non-Beijing strains in previously treated cases of children (P = 0.01, 0.01 and 0.025, respectively).

Conclusion/Significance

Beijing family was more prevalent in northern and central China compared to southern China and these strains were predominant in all age groups. The genetic diversity of M. tuberculosis isolates from children was similar to that found in adolescents and adults. Beijing genotype was associated with RIF, STR and MDR resistance in previously treated children.     

Elimination of Iron Deficiency Anemia and Soil Transmitted Helminth Infection: Evidence from a Fifty-four Month Iron-Folic Acid and De-worming Program

Background

Intermittent iron-folic acid supplementation and regular de-worming are effective initiatives to reduce anemia, iron deficiency, iron deficiency anemia, and soil transmitted helminth infections in women of reproductive age. However, few studies have assessed the long-term effectiveness of population-based interventions delivered in resource-constrained settings.

Methodology/Principal Findings

The objectives were to evaluate the impact of weekly iron-folic acid supplementation and de-worming on mean hemoglobin and the prevalence of anaemia, iron deficiency, and soil transmitted helminth infection in a rural population of women in northern Vietnam and to identify predictive factors for hematological outcomes. A prospective cohort design was used to evaluate a population-based supplementation and deworming program over 54 months. The 389 participants were enrolled just prior to commencement of the intervention. After 54 months 76% (95% CI [68%, 84%]) were taking the iron-folic acid supplement and 95% (95% CI [93%, 98%]) had taken the most recently distributed deworming treatment. Mean hemoglobin rose from 122 g/L (95% CI [120, 124]) to 131 g/L (95% CI [128, 134]) and anemia prevalence fell from 38% (95% CI [31%, 45%]) to 18% (95% CI [12%, 23%]); however, results differed significantly between ethnic groups. Iron deficiency fell from 23% (95% CI [17%, 29%]) to 8% (95% CI [4%, 12%]), while the prevalence of iron deficiency anemia was reduced to 4% (95% CI [1%, 7%]). The prevalence of hookworm infection was reduced from 76% (95% CI [68%, 83%]) to 11% (95% CI [5%, 18%]). The level of moderate or heavy infestation of any soil-transmitted helminth was reduced to less than 1%.

Conclusions/Significance

Population-based interventions can efficiently and effectively reduce anemia and practically eliminate iron deficiency anemia and moderate to heavy soil transmitted helminth infections, maintaining them below the level of public health concern.     

Molecular dynamics study on the correlation between structure and sensitivity for defective RDX crystals and their PBXs

Molecular dynamics simulation was applied to investigate the sensitivities of perfect and defective RDX (cyclotrimethylene trinitramine) crystals, as well as their PBXs (polymer-bonded explosives) with the polymeric binder F₂₃₁₁, in the NPT (constant number of particles, constant pressure, constant temperature) ensemble using the COMPASS force field. Five kinds of defects—two dislocations, one vacancy, and two types of doping—were considered separately. The bond length distribution and the maximum (L _max) and average (L _ave) bond lengths of the N–NO₂ trigger bonds in RDX were obtained and their relationships to the sensitivities of RDX and PBXs are discussed. L _max was found to be an important structural parameter for judging the relative sensitivity, and defects were observed to have little effect on the sensitivities of PBXs, due to the strong desensitizing effect of the polymer F₂₃₁₁.     

Theoretical study on aluminum carbide endohedral fullerene-Al4C@C80

The possibility of a new endohedral fullerene with a trapped aluminum carbide cluster, Al₄C @C₈₀-I _h , was theoretical investigated. The geometries and electronic properties of it were investigated using density functional theory methods. The Al₄C unit formally transfers six electrons to the C₈₀ cage which induces stabilization of Al₄C@C₈₀. A favorable binding energy, relatively large HOMO-LUMO gap, electron affinities and ionization potentials suggested the Al₄C@C₈₀ is rather stable. The analysis of vertical ionization potential and vertical electron affinity indicate Al₄C@C₈₀ is a good electron acceptor.

Cyclo-hexa-peptides at the water/cyclohexane interface: a molecular dynamics simulation

Molecular dynamic (MD) simulations have been performed to study the behaviors of ten kinds of cyclo-hexa-peptides (CHPs) composed of amino acids with the diverse hydrophilic/hydrophobic side chains at the water/cyclohexane interface. All the CHPs take the “horse-saddle” conformations at the interface and the hydrophilicity/hydrophobicity of the side chains influences the backbones’ structural deformations. The orientations and distributions of the CHPs at the interface and the differences of interaction energies (ΔΔE) between the CHPs and the two liquid phases have been determined. RDF analysis shows that the H-bonds were formed between the O_C atoms of the CHPs’ backbones and H_w atoms of water molecules. N atoms of the CHPs’ backbones formed the H-bonds or van der Waals interactions with the water solvent. It was found that there is a parallel relationship between ΔΔE and the lateral diffusion coefficients (D _xy ) of the CHPs at the interface. The movements of water molecules close to the interface are confined to some extent, indicating that the dynamics of the CHPs and interfacial water molecules are strongly coupled.