Causal relationship between gut microbiota and childhood obesity: A Mendelian randomization study and case-control study.

BACKGROUND: Gut microbiota and obesity are deeply interconnected. However, the causality in the relationship between these factors remains unclear. Therefore, this study aimed to elucidate the genetic relationship between gut microbiota and childhood obesity. METHODS: Genetic summary statistics for the gut microbiota were obtained from the MiBioGen consortium. Genome-wide association studies (GWAS) summary data for childhood obesity were obtained from North American, Australian, and European collaborative genome-wide meta-analyses. Mendelian randomization (MR) analyses were performed using the inverse variance weighting method. 16 children with obesity and 16 without obesity were included for clinical observation, and their weight, body mass index, blood lipid levels, and gut microbiology were assessed. Paired t-test was the primary method of data analysis, and statistical significance was set at P < 0.05. RESULTS: MR identified 16 causal relationships between the gut microbiome and childhood obesity. In the case-control study, we found that five gut microorganisms differed between children with and without obesity, whereas three gut microorganisms changed after weight loss in children with obesity. CONCLUSION: Our study provides new insights into the genetic mechanisms underlying gut microbiota and childhood obesity. TRIAL REGISTRATION NUMBER: ChiCTR2300072179. NAME OF REGISTRY: Change of intestinal flora and plasma metabolome in obese children and their weight loss intervention: a randomized controlled tria URL OF REGISTRY: https://www.chictr.org.cn/showproj.html. DATE OF REGISTRATION: 2023-06-06. DATE OF ENROLMENT OF THE FIRST PARTICIPANT TO THE TRIAL: 2023-06-07.

The effects of diet quality, eating behavior, and sleep on the academic performance among elementary school students.

The academic success of children contributes to their income, social status, and public health. This study was conducted with 217 elementary school students from western China. Scores on the Chinese Children Dietary Index (CCDI), Dietary Approaches to Stop Hypertension (DASH), adjusted DASH, and KIDMED index were calculated to evaluate diet quality. Eating behavior and sleep quality were assessed using the Children's Eating Behavior Questionnaire (CEBQ) and Children's Sleep Habits Questionnaire (CHSQ), respectively. Academic achievement was measured using school-provided average grades. Higher CCDI scores, longer sleep time, lower total CHSQ scores, and lower subscores on "satiety responsiveness," "slowness in eating," "emotional undereating," and "food fussiness" dimensions of the CEBQ were associated with high academic achievement. In conclusion, good diet quality, sleep quality, healthy eating behaviors, and adequate sleep duration were associated with better academic performance. Interventions are recommended to be developed in education system to improve healthy diets and lifestyles, enhancing academic achievement.

Genetically engineered nanomodulators elicit potent immunity against cancer stem cells by checkpoint blockade and hypoxia relief.

Rapid development of checkpoint inhibitors has provided significant breakthroughs for cancer stem cell (CSC) therapy, while the therapeutic efficacy is restricted by hypoxia-mediated tumor immune evasion, especially hypoxia-induced CD47 overexpression in CSCs. Herein, we developed a genetically engineered CSC membrane-coated hollow manganese dioxide (hMnO2@gCMs) to elicit robust antitumor immunity by blocking CD47 and alleviating hypoxia to ultimately achieve the eradication of CSCs. The hMnO2 core effectively alleviated tumor hypoxia by inducing decomposition of tumor endogenous H2O2, thus suppressing the CSCs and reducing the expression of CD47. Cooperating with hypoxia relief-induced downregulation of CD47, the overexpressed SIRPα on gCM shell efficiently blocked the CD47-SIRPα "don't eat me" pathway, synergistically eliciting robust antitumor-mediated immune responses. In a B16F10-CSC bearing melanoma mouse model, the hMnO2@gCMs showed an enhanced therapeutic effect in eradicating CSCs and inhibiting tumor growth. Our work presents a simple, safe, and robust platform for CSC eradication and cancer immunotherapy.

Genetically Edited Cascade Nanozymes for Cancer Immunotherapy.

Immune checkpoint blockade (ICB) has brought tremendous clinical progress, but its therapeutic outcome can be limited due to insufficient activation of dendritic cells (DCs) and insufficient infiltration of cytotoxic T lymphocytes (CTLs). Evoking immunogenic cell death (ICD) is one promising strategy to promote DC maturation and elicit T-cell immunity, whereas low levels of ICD induction of solid tumors restrict durable antitumor efficacy. Herein, we report a genetically edited cell membrane-coated cascade nanozyme (gCM@MnAu) for enhanced cancer immunotherapy by inducing ICD and activating the stimulator of the interferon genes (STING) pathway. In the tumor microenvironment (TME), the gCM@MnAu initiates a cascade reaction and generates abundant cytotoxic hydroxyl (•OH), resulting in improved chemodynamic therapy (CDT) and boosted ICD activation. In addition, released Mn2+ during the cascade reaction activates the STING pathway and further promotes the DC maturation. More importantly, activated immunogenicity in the TME significantly improves gCM-mediated PD-1/PD-L1 checkpoint blockade therapy by eliciting systemic antitumor responses. In breast cancer subcutaneous and lung metastasis models, the gCM@MnAu showed synergistically enhanced therapeutic effects and significantly prolonged the survival of mice. This work develops a genetically edited nanozyme-based therapeutic strategy to improve DC-mediated cross-priming of T cells against poorly immunogenic solid tumors.

Tea polyphenol-engineered hybrid cellular nanovesicles for cancer immunotherapy and androgen deprivation therapy.

Androgen deprivation therapy (ADT) is a crucial and effective strategy for prostate cancer, while systemic administration may cause profound side effects on normal tissues. More importantly, the ADT can easily lead to resistance by involving the activation of NF-κB signaling pathway and high infiltration of M2 macrophages in tumor microenvironment (TME). Herein, we developed a biomimetic nanotherapeutic platform by deriving cell membrane nanovesicles from cancer cells and probiotics to yield the hybrid cellular nanovesicles (hNVs), loading flutamide (Flu) into the resulting hNVs, and finally modifying the hNVs@Flu with Epigallocatechin-3-gallate (EGCG). In this nanotherapeutic platform, the hNVs significantly improved the accumulation of hNVs@Flu-EGCG in tumor sites and reprogramed immunosuppressive M2 macrophages into antitumorigenic M1 macrophages, the Flu acted on androgen receptors and inhibited tumor proliferation, and the EGCG promoted apoptosis of prostate cancer cells by inhibiting the NF-κB pathway, thus synergistically stimulating the antitumor immunity and reducing the side effects and resistance of ADT. In a prostate cancer mouse model, the hNVs@Flu-EGCG significantly extended the lifespan of mice with tumors and led to an 81.78% reduction in tumor growth compared with the untreated group. Overall, the hNVs@Flu-EGCG are safe, modifiable, and effective, thus offering a promising platform for effective therapeutics of prostate cancer.

Hybrid Cellular Nanovesicles Block PD-L1 Signal and Repolarize M2 Macrophages for Cancer Immunotherapy.

The PD1/PD-L1 immune checkpoint blocking is a promising therapy, while immunosuppressive tumor microenvironment (TME) and poor tumor penetration of therapeutic antibodies limit its efficacy. Repolarization of tumor-associated macrophages (TAMs) offers a potential method to ameliorate immunosuppression of TME and further boost T cell antitumor immunity. Herein, hybrid cell membrane biomimetic nanovesicles (hNVs) are developed by fusing M1 macrophage-derived nanovesicles (M1-NVs) and PD1-overexpressed tumor cell-derived nanovesicles (PD1-NVs) to improve cancer immunotherapy. The M1-NVs promote the transformation of M2-like TAMs to M1-like phenotype and further increase the release of pro-inflammatory cytokines, resulting in improved immunosuppressive TME. Concurrently, the PD1-NVs block PD1/PD-L1 pathway, which boosts cancer immunotherapy when combined with M1-NVs. In a breast cancer mouse model, the hNVs efficiently accumulate at the tumor site after intravenous injection and significantly inhibit the tumor growth. Mechanically, the M1 macrophages and CD8+ T lymphocytes in TME increase by twofold after the treatment, indicating effective immune activation. These results suggest the hNVs as a promising strategy to integrate TME improvement with PD1/PD-L1 blockade for cancer immunotherapy.

Genetically Engineered Cytomembrane Nanovaccines for Cancer Immunotherapy.

Cancer nanovaccines have attracted widespread attention by inducing potent cytotoxic T cell responses to improve immune checkpoint blockade (ICB) therapy, while the lack of co-stimulatory molecules limits their clinical applications. Here, a genetically engineered cancer cytomembrane nanovaccine is reported that simultaneously overexpresses co-stimulatory molecule CD40L and immune checkpoint inhibitor PD1 to elicit robust antitumor immunity for cancer immunotherapy. The CD40L and tumor antigens inherited from cancer cytomembranes effectively stimulate dendritic cell (DC)-mediated immune activation of cytotoxic T cells, while the PD1 on cancer cytomembranes significantly blocks PD1/PD-L1 signaling pathway, synergistically stimulating antitumor immune responses. Benefiting from the targeting ability of cancer cytomembranes, this nanovaccines formula shows an enhanced lymph node trafficking and retention. Compared with original cancer cytomembranes, this genetically engineered nanovaccine induces twofold DC maturation and shows satisfactory precaution efficacy in a breast tumor mouse model. This genetically engineered cytomembrane nanovaccine offers a simple, safe, and robust strategy by incorporating cytomembrane components and co-stimulatory molecules for enhanced cancer immunotherapy.

Triple Hybrid Cellular Nanovesicles Promote Cardiac Repair after Ischemic Reperfusion.

The management of myocardial ischemia/reperfusion (I/R) damage in the context of reperfusion treatment remains a significant hurdle in the field of cardiovascular disorders. The injured lesions exhibit distinctive features, including abnormal accumulation of necrotic cells and subsequent inflammatory response, which further exacerbates the impairment of cardiac function. Here, we report genetically engineered hybrid nanovesicles (hNVs), which contain cell-derived nanovesicles overexpressing high-affinity SIRPα variants (SαV-NVs), exosomes (EXOs) derived from human mesenchymal stem cells (MSCs), and platelet-derived nanovesicles (PLT-NVs), to facilitate the necrotic cell clearance and inhibit the inflammatory responses. Mechanistically, the presence of SαV-NVs suppresses the CD47-SIRPα interaction, leading to the promotion of the macrophage phagocytosis of dead cells, while the component of EXOs aids in alleviating inflammatory responses. Moreover, the PLT-NVs endow hNVs with the capacity to evade immune surveillance and selectively target the infarcted area. In I/R mouse models, coadministration of SαV-NVs and EXOs showed a notable synergistic effect, leading to a significant enhancement in the left ventricular ejection fraction (LVEF) on day 21. These findings highlight that the hNVs possess the ability to alleviate myocardial inflammation, minimize infarct size, and improve cardiac function in I/R models, offering a simple, safe, and robust strategy in boosting cardiac repair after I/R.

Trifluoromethyl Rhodium-Carbynoid in [2+1+2] Cycloadditions.

Trifluoromethyl cationic carbyne (CF3 C+ :) possessing dual carbene-carbocation behavior emulated as trifluoromethyl metal-carbynoid (CF3 C+ =M) has not been explored yet, and its reaction characteristics are unknown. Herein, a novel α-diazotrifluoroethyl sulfonium salt was prepared and used in Rh-catalyzed three-component [2+1+2] cycloadditions for the first time with commercially available N-fused heteroarenes and nitriles, yielding a series of imidazo[1,5-a] N-heterocycles that are of interest in medicinal chemistry, in which the insertion of trifluoromethyl Rh-carbynoid (CF3 C+ =Rh) into C=N bonds of N-fused heteroarenes was involved. This strategy demonstrates synthetic applications in late-stage modification of pharmaceuticals, construction of CD3 -containing N-heterocycles, gram-scale experiments, and synthesis of phosphodiesterase 10A inhibitor analog. These highly valuable and modifiable imidazo[1,5-a] N-heterocycles exhibit good antitumor activity in vitro, thus demonstrating their potential applications in medicinal chemistry.

Dealuminated Beta zeolite reverses Ostwald ripening for durable copper nanoparticle catalysts.

Copper nanoparticle-based catalysts have been extensively applied in industry, but the nanoparticles tend to sinter into larger ones in the chemical atmospheres, which is detrimental to catalyst performance. In this work, we used dealuminated Beta zeolite to support copper nanoparticles (Cu/Beta-deAl) and showed that these particles become smaller in methanol vapor at 200°C, decreasing from ~5.6 to ~2.4 nanometers in diameter, which is opposite to the general sintering phenomenon. A reverse ripening process was discovered, whereby migratable copper sites activated by methanol were trapped by silanol nests and the copper species in the nests acted as new nucleation sites for the formation of small nanoparticles. This feature reversed the general sintering channel, resulting in robust catalysts for dimethyl oxalate hydrogenation performed with supported copper nanoparticles for use in industry.

Physical regulation of copper catalyst with a hydrophobic promoter for enhancing CO2 hydrogenation to methanol.

The hydrogenation of CO2 to methanol, which is restricted by water products, requires a selective removal of water from the reaction system. Here, we show that physically combining hydrophobic polydivinylbenzene with a copper catalyst supported by silica can increase methanol production and CO2 conversion. Mechanistic investigation reveals that the hydrophobic promoter could hinder the oxidation of copper surface by water, maintaining a small fraction of metallic copper species on the copper surface with abundant Cuδ+, resulting in high activity for the hydrogenation. Such a physically mixed catalyst survives the continuous test for 100 h owing to the thermal stability of the polydivinylbenzene promoter.

In situ formed scaffold with royal jelly-derived extracellular vesicles for wound healing.

Background: Safe and effective wound healing can be a major clinical challenge. Inflammation and vascular impairment are two main causes of inadequate wound healing. Methods: Here, we developed a versatile hydrogel wound dressing, comprising a straightforward physical mixture of royal jelly-derived extracellular vesicles (RJ-EVs) and methacrylic anhydride modified sericin (SerMA), to accelerate wound healing by inhibiting inflammation and promoting vascular reparation. Results: The RJ-EVs showed satisfactory anti-inflammatory and antioxidant effects, and significantly promoted L929 cell proliferation and migration in vitro. Meanwhile, the photocrosslinked SerMA hydrogel with its porous interior structure and high fluidity made it a good candidate for wound dressing. The RJ-EVs can be gradually released from the SerMA hydrogel at the wound site, ensuring the restorative effect of RJ-EVs. In a full-thickness skin defect model, the SerMA/RJ-EVs hydrogel dressing accelerated wound healing with a healing rate of 96.8% by improving cell proliferation and angiogenesis. The RNA sequencing results further revealed that the SerMA/RJ-EVs hydrogel dressing was involved in inflammatory damage repair-related pathways including recombinational repair, epidermis development, and Wnt signaling. Conclusion: This SerMA/RJ-EVs hydrogel dressing offers a simple, safe and robust strategy for modulating inflammation and vascular impairment for accelerated wound healing.

Screening and Evaluation of Novel α-Glucosidase Inhibitory Peptides from Ginkgo biloba Seed Cake Based on Molecular Docking Combined with Molecular Dynamics Simulation.

Food-derived α-glucosidase inhibitory peptides have gained significant interest in treating type 2 diabetes mellitus (T2DM) owing to their favorable safety profiles. Molecular docking combined with molecular dynamics simulation was performed to screen α-glucosidase inhibitory peptides from Ginkgo biloba seed cake (GBSC), and two novel peptides (Met-Pro-Gly-Pro-Pro (MPGPP) and Phe-Ala-Pro-Ser-Trp (FAPSW)) were acquired. The results of molecular docking and molecular dynamics simulation suggested that FAPSW and MPGPP could generate stable complexes with 3wy1, and the electrostatic and van der Waals forces played contributory roles in FAPSW and MPGPP binding to 3wy1. The α-glucosidase inhibition assay corroborated that FAPSW and MPGPP had good α-glucosidase inhibition capacity, with IC50 values of 445.34 ± 49.48 and 1025.68 ± 140.78 µM, respectively. In vitro simulated digestion results demonstrated that FAPSW and MPGPP strongly resisted digestion. These findings lay a theoretical foundation for FAPSW and MPGPP in treating T2DM.

Simultaneous passivation on both A and X sites of halogen perovskite with magnesium benzoate.

Surface modification engineering is a well-known effective passivation method for making efficient and stable perovskite solar cells (PSCs). However, to our knowledge, little attention has been paid to simultaneously passivating the A and X sites of halogen perovskites. Herein, we introduced an organometallic salt (C6H5COO)2Mg (MgBEN) as a passivator, and as a result, the C6H5COOMg+ passivates the A site and C6H5COO- the X site on the perovskite layer, significantly reducing the trap-state density and nonradiative recombination. Moreover, the modification induces the perovskite film quality to improve, which may decrease the charge accumulation and facilitate carrier transport. By optimizing the concentration of the MgBEN, the perovskite film showed an increased grain size (from 1.18 µm to 1.61 µm), and the best device exhibited an enhanced power conversion efficiency (PCE) of 22.24%. Meanwhile, the device after modification performed with good long-term stability.

Boosting Checkpoint Immunotherapy with Biomaterials.

The immune checkpoint blockade (ICB) therapy has revolutionized the field of cancer treatment, while low response rates and systemic toxicity limit its clinical outcomes. With the rapid advances in nanotechnology and materials science, various types of biomaterials have been developed to maximize therapeutic efficacy while minimizing side effects by increasing tumor antigenicity, reversing immunosuppressive microenvironment, amplifying antitumor immune response, and reducing extratumoral distribution of checkpoint inhibitors as well as enhancing their retention within target sites. In this review, we reviewed current design strategies for different types of biomaterials to augment ICB therapy effectively and then discussed present representative biomaterial-assisted immune modulation and targeted delivery of checkpoint inhibitors to boost ICB therapy. Current challenges and future development prospects for expanding the ICB with biomaterials were also summarized. We anticipate this review will be helpful for developing emerging biomaterials for ICB therapy and promoting the clinical application of ICB therapy.

Novel bioactive peptides from ginkgo biloba seed protein and evaluation of their α-glucosidase inhibition activity.

The inhibition of α-glucosidase activity has been recognized as an effective approach for treating type 2 diabetes mellitus (T2DM). In recent years, much emphasis has been placed on identifying peptides with α-glucosidase inhibitory activity and elucidating the mechanisms underlying their inhibitory effect in treating T2DM. This study aims to identify peptides with good α-glucosidase inhibitory activity from the hydrolysate of ginkgo biloba seed cake protein isolate (GCPI) using in silico screening. It was found that the hydrolysate from Alcalase exhibited the strongest inhibitory effect on α-glucosidase (IC50 12.94 ± 0.37 mg/mL). Three novel peptides with α-glucosidase inhibitory activity, i.e., Leu-Ser-Met-Ser-Phe-Pro-Pro-Phe (LSMSFPPF), Val-Pro-Lys-Ile-Pro-Pro-Pro (VPKIPPP) and Met-Pro-Gly-Pro-Pro-Ser-Asp (MPGPPSD), were further identified from the hydrolysate of Alcalase by in silico screening. LSMSFPPF exhibited the strongest inhibitory activity (IC50 454.33 ± 32.45 µM), followed by MPGPPSD (IC50 943.82 ± 73.10 µM) and VPKIPPP (IC50 1446.81 ± 66.98 µM). The pharmacophore model revealed that hydrogen bonds played a critical role in α-glucosidase inhibition.

Circulating THBS1: A Risk Factor for Nonalcoholic Fatty Liver Disease in Obese Children.

INTRODUCTION: Thrombospondin 1 (THBS1) is a highly expressed adipokine in adults with obesity. In the present study, we aimed to investigate the clinical significance of THBS1in children with obesity and nonalcoholic fatty liver disease (NAFLD) and determine the effect of metformin on THBS1 expression in dietary-induced obese (DIO) mice. METHODS: A cross-sectional study was conducted among 78 obese children and 35 nonobese children. Anthropometric parameters, clinical data, and circulating THBS1 levels were measured. The expression of THBS1 was detected in the serum and liver tissue from diet-induced obese mice (C57BL/6) with or without metformin treatment. RESULTS: Higher THBS1 levels were observed in children with NAFLD and higher SDS-BMI. Individuals in the higher THBS1 quartile had a higher prevalence of hypo-high-density lipoprotein cholesterol (HDL-C). Logistic regression analysis showed a significant correlation between THBS1 and NAFLD, as well as between hip circumference and leptin levels. Receiver-operating characteristic (ROC) analysis revealed that THBS1 was a more sensitive predictor of NAFLD than leptin. Additionally, metformin ameliorated hepatic steatosis and decreased hepatic THBS1 expression in high-fat diet (HFD)-fed mice. CONCLUSIONS: Circulating THBS1 level may be a risk factor for NAFLD in obese children. Our findings provided a novel approach of metformin administration for the prevention and treatment of NAFLD. This study also confirmed that metformin decreased the expression of hepatic THBS in DIO mice.

Physical mixing of a catalyst and a hydrophobic polymer promotes CO hydrogenation through dehydration.

In many reactions restricted by water, selective removal of water from the reaction system is critical and usually requires a membrane reactor. We found that a simple physical mixture of hydrophobic poly(divinylbenzene) with cobalt-manganese carbide could modulate a local environment of catalysts for rapidly shipping water product in syngas conversion. We were able to shift the water-sorption equilibrium on the catalyst surface, leading to a greater proportion of free surface that in turn raised the rate of syngas conversion by nearly a factor of 2. The carbon monoxide conversion reached 63.5%, and 71.4% of the hydrocarbon products were light olefins at 250°C, outperforming poly(divinylbenzene)-free catalyst under equivalent reaction conditions. The physically mixed CoMn carbide/poly(divinylbenzene) catalyst was durable in the continuous test for 120 hours.

Neutrophil membrane-coated immunomagnetic nanoparticles for efficient isolation and analysis of circulating tumor cells.

The isolation and analysis of scarce circulating tumor cells (CTCs) with immunomagnetic nanoparticles (IMNs) have shown promising outcomes in noninvasive cancer diagnosis. However, the IMNs adsorb nonspecific proteins after entering into biofluids and the formed protein coronas cover surface targeting ligands, limiting the detection efficiency of IMNs. In addition, the interaction between surface targeting ligands and white blood cells (WBCs) significantly limits the purity of CTCs isolated by IMNs. Furthermore, the interfacial collision of nanoparticles and cells has negative effects on the viability of isolated CTCs. All of these limitations synthetically restrict the isolation and analysis of rare CTCs for early diagnosis and precision medicine. Here, we proposed that surface functionalization of IMNs with neutrophil membranes can simultaneously reduce nonspecific protein adsorption, enhance the interaction with CTCs, reduce the distraction from WBCs, and improve the viability of isolated CTCs. In spiked blood samples, our neutrophil membrane-coated IMNs (Neu-IMNs) exhibited a superior separation efficiency from 41.36% to 96.82% and an improved purity from 40.25% to 90.68% when compared to bare IMNs. Additionally, we successfully isolated CTCs in 19 out of total 20 blood samples from breast cancer patients using Neu-IMNs and further confirmed the feasibility of the isolated CTCs for downstream cell sequencing. Our work provides a new perspective on engineered IMNs for efficient isolation and analysis of CTCs, paving the way for early noninvasive diagnosis of cancer.

Follistatin-Like 1 and Family with Sequence Similarity to 19 Member A5 Levels Are Decreased in Obese Children and Associated with Glucose Metabolism.

INTRODUCTION: Childhood obesity is a significant and growing problem worldwide. Recent evidence suggests Follistatin-like 1 (FSTL1) and family with sequence similarity to 19 member A5 (FAM19A5) to be novel adipokines. However, very few studies have examined the plasma levels of FSTL1 and FAM19A5 in children. Therefore, this cross-sectional study evaluated the association between serum FSTL1 and FAM19A5 levels and obesity in children and investigated the relationship between FSTL1 and FAM19A5 and glucose metabolism or endothelial injury. METHODS: Fifty-five obese children and 48 healthy controls were recruited. Plasma FSTL1 and FAM19A5 levels were detected using ELISA. In addition, the association between the clinical data and anthropometric parameters was analyzed. RESULTS: Serum FAM19A5 levels were significantly decreased in the obese children, at 189.39 ± 19.10 pg/mL, compared with those without obesity, at 211.08 ± 38.09 pg/mL. Serum concentrations of FSTL1 were also significantly lower in the obese children, at 0.64 (0.37-0.64) ng/mL, compared with those without obesity, at 1.35 (1.05-2.12) ng/mL. In addition, FAM19A5 (OR = 0.943; p = 0.003) was a predictor of insulin resistance in obese children compared with healthy controls. Lastly, serum FAM19A5 and FSTL1 played mediating roles in insulin resistance in children. CONCLUSION: The serum levels of FAM19A5 and FSTL1 were decreased in obese children; therefore, FAM19A5 and FSTL1 likely play important roles in glucose metabolism in obese children.