Regional anthropometric measures associated with the severity of liver injury in patients with non-alcoholic fatty liver disease

BACKGROUND

Not all NAFLD patients are obese and many obese patients do not have NAFLD. Impaired peripheral fat storage may increase the delivery of lipids to the liver and facilitate NAFLD progression.

AIM

To assess the association of anthropometric measures of regional adiposity including arm fat index (AFI) (upper body fat), waist circumference (visceral fat) and body mass index (total body fat) on liver injury and fibrosis in NAFLD.

METHODS

One hundred and forty-one patients with histological evidence of NAFLD were included in this study. Multivariate logistic regression models examined the contribution of age, sex, body mass index, AFI, triceps fold thickness (TST), waist and hip circumference to the odds of liver injury (NAS scores ≥3) and fibrosis (fibrosis scores ≥2) by liver biopsy.

RESULTS

Arm fat index (OR: 0.82, 95% CI: 0.59-0.91) and TST (OR: 0.13, 95% CI: 0.04-0.42) were negatively correlated with NAFLD histological severity. In women, waist circumference was positively correlated with NAFLD severity (OR: 1.21(1.02-1.44). Age (OR: 1.05, 95% CI: 1.01-1.0) and waist circumference (OR: 1.07, 95% CI: 1.00-1.15) were significantly associated with fibrosis risk. In women, AFI (OR: 0.87, 95% CI: 0.76-0.99) and TST (OR: 0.22, 95% CI: 0.05-0.95) were negatively associated with fibrosis risk.

CONCLUSIONS

Regional anthropometric measures are associated with severity of NAFLD in a sex-specific manner. Men and women with lower arm fat depots and women with bigger waist circumference have a greater likelihood of liver injury. Age and waist circumference seem to be associated with liver fibrosis. Simple anthropometric measurements of peripheral fat deposits may help stratify significant liver injury risk.

Molecular dynamics simulations of retinoblastoma protein

Tumor suppressor proteins play a crucial role in cell cycle regulation. Retinoblastoma protein (pRB) is one among them which regulates G1-S transition by binding with transcription factors. The activity of pRB is deregulated by cyclin dependent kinases-mediated hyper-phosphorylation and also due to cancer-derived mutations. In addition, it is also deactivated by binding of viral onco-proteins such as large T antigen, E1A, and E7. These viral proteins initially recognize pRB through their conserved LxCxE motif and facilitate dissociation of preexisting pRB-E2F complex. Based on these features, molecular dynamics (MD) simulation is performed for four different states of pRB for which the crystal structure is available. The unliganded/apo form and complex forms with E2F and E7 peptides reveal the molecular mechanism behind the activation and inactivation of pRB. In addition, the ternary complex of pRB with both E7 and E2F (for which no crystal structure is available) is modeled and simulated to understand the influence of binding of one ligand on the other. The variations in the three major factors such as conformational changes, inter- and intra-molecular interactions, and binding free energies between the apo and complex forms confirm the possibility for designing a small molecule inhibitor to inhibit pRB-E7 interactions without altering the prebound E2F. The present study deals with the molecular modeling and MD simulations of pRB in free and ligand-bound forms and confirms that pRB could be a valid target for the anticancer drug design when the cancer is induced by the viral onco-proteins and forms a clear base for designing E7 antagonists.

T regulatory cells play a significant role in modulating MHC class I antibody-induced obliterative airway disease

The molecular mechanisms leading to the development of chronic lung allograft dysfunction following de novo development of antibodies to mismatched donor MHC remain undefined. We demonstrated that intrabronchial administration of antibodies to MHC class I resulted in induction of both innate and adaptive cellular immune responses characterized by a predominance of Th17 specific to lung associated self-antigens Kα1-tubulin and Collagen-V leading to the development of obliterative airway lesions (OAD), correlate of chronic rejection following human lung transplantation. To determine the role of regulatory T cells (Treg) in the pathogenesis of OAD, we administered anti-MHC class I to mice, in which Treg were depleted by conditional ablation of FoxP3+cells. Under this condition, we observed a threefold increase in pulmonary cellular infiltration, luminal occlusion and fibrous deposition when compared anti-MHC class I Ab administered mice maintaining FoxP3. OAD lesions were accompanied with enhanced accumulation of neutrophils along with self-antigen-specific Th17 and humoral responses. However, IL-17-blockade or adoptive transfer of Treg abrogated OAD. We conclude that Treg exerts a suppressive effect on anti-MHC induced IL-8-mediated neutrophil infiltration and innate immune responses that leads to inhibition of Th17 immune responses to lung associated self-antigens which is critical for development of OAD.

On the perturbation of the H-bonding interaction in ethylene glycol clusters upon hydration

Ab initio and density functional methods have been employed to study the structure, stability, and spectral properties of various ethylene glycol (EG(m)) and ethylene glycol-water (EG(m)W(n)) (m = 1-3, n = 1-4) clusters. The effective fragment potential (EFP) approach was used to explore various possible EG(m)W(n) clusters. Calculated interaction energies of EG(m)W(n) clusters confirm that the hydrogen-bonding interaction between EG molecules is perturbed by the presence of water molecules and vice versa. Further, energy decomposition analysis shows that both electrostatic and polarization interactions predominantly contribute to the stability of these clusters. It was found from the same analysis that ethylene glycol-water interaction is predominant over the ethylene glycol-ethylene glycol and water-water interactions. Overall, the results clearly illustrate that the presence of water disrupts the ethylene glycol-ethylene glycol hydrogen bonds.

Studies on the structure, stability, and spectral signatures of hydride ion-water clusters

The gas-phase structure, stability, spectra, and electron density topography of H(-)W(n) clusters (where n = 1-8) have been calculated using coupled-cluster CCSD(T) and Møller-Plesset second-order perturbation (MP2) theory combined with complete basis set (CBS) approaches. The performance of various density functional theory (DFT) based methods such as B3LYP, M05-2X, M06, M06-L, and M06-2X using 6-311++G(d,p), and aug-cc-pVXZ (aVXZ, where X = D, T, and Q) basis sets has also been assessed by considering values calculated using CCSD(T)/CBS limit as reference. The performance of the functionals has been ranked based on the mean signed/unsigned error. The comparison of geometrical parameters elicits that the geometrical parameters predicted by B3LYP/aVTZ method are in good agreement with those values obtained at MP2/aVTZ level of theory. Results show that M05-2X functional outperform other functionals in predicting the energetics when compared to CCSD(T)/CBS value. On the other hand, values predicted by M06-2X, and M06 methods, are closer to those values obtained from MP2/CBS approach. It is evident from the calculations that H(-)W(n) (where n = 5-8) clusters adopt several interesting structural motifs such as pyramidal, prism, book, Clessidra, cubic, cage, and bag. The important role played by ion-water (O-H···H(-)) and water-water (O-H···O) interactions in determining the stability of the clusters has also been observed. Analysis of the results indicates that the most stable cluster is made up of minimum number of O-H···H(-) interaction in conjugation with the maximum number of O-H···O interactions. The Bader theory of atoms in molecules (AIM) and natural bond orbital (NBO) analyses has also been carried out to characterize the nature of interactions between hydride ion and water molecules. It can be observed from the vibrational spectra of H(-)W(n) clusters, the stretching frequencies involving ion-water interaction always exhibit larger redshift and intensities than that of water-water (inter solvent) interactions.

Endoscopic evaluation of the gastro-duodenal tolerance of short-term analgesic treatment with 25 mg diclofenac-K liquid capsules

BACKGROUND

Diclofenac-potassium (diclofenac--K) 25 mg liquid capsule is absorbed more quickly than the tablet formulation. It offers potential for rapid pain relief, but may alter gastro-duodenal tolerability.

AIM

To evaluate the gastro-duodenal tolerance of diclofenac-K 25 mg liquid capsules vs. diclofenac-K 12.5 mg tablets, acetylsalicylic acid (ASA) 500 mg tablets and ibuprofen 200 mg liquid capsules.

METHODS

In an endoscopist-blinded, randomised, parallel-group study, volunteers received 15 doses of diclofenac-K 25 mg liquid capsules (n = 36), diclofenac-K 2 × 12.5 mg tablets (n = 36), ibuprofen 2 × 200 mg liquid capsules (n = 24) or ASA 2 × 500 mg tablets (n = 36) over 5 days. The primary outcome was the incidence of erosive gastro-duodenal lesions at Day 6. Secondary outcomes included modified Lanza score and change in gastric mucosal prostaglandin synthesis.

RESULTS

The lowest incidence of erosive gastro-duodenal lesions was with diclofenac-K liquid capsules (53%), compared to 61% with diclofenac-K tablets (P = 0.52), 75% with ibuprofen (P = 0.08) and 94% with ASA (P = 0.001). Results were similar for the Lanza scores, although diclofenac-K liquid capsules were significantly superior to ibuprofen liquid capsules (P = 0.04). Diclofenac-K liquid capsules inhibited prostaglandin synthesis by 52% compared to 64% for diclofenac-K tablets (P = 0.10), 50% for ibuprofen (P = 0.85) and 79% for ASA (P = 0.002). With respect to safety, adverse events were most frequent in the ASA group, predominantly gastrointestinal events.

CONCLUSIONS

Mucosal injury with diclofenac-K liquid 25 mg liquid capsules was similar to diclofenac-K 25 mg tablets, significantly lower than ASA 1 g tablets and showed some superiority over ibuprofen 400 mg liquid capsules (EudraCT Number 2009-011278-14).

An obligatory role for lung infiltrating B cells in the immunopathogenesis of obliterative airway disease induced by antibodies to MHC class I molecules

Using a murine model, we demonstrated that endobronchial administration of antibodies (Abs) to major histocompatibility complex (MHC) class I results in cellular infiltration, epithelial metaplasia, fibrosis and obstruction of the small airways (obliterative airway disease [OAD]) mediated predominantly by Th17 responses to self-antigens. This resembles bronchiolitis obliterans syndrome developed following human lung transplantation. Since B cells play a crucial role in induction of autoimmune responses, we defined the role of B cells and its antigen presenting properties in induction of OAD in this study. Anti-MHC class I was administered endobronchially in B(-/-) and wild-type mice. In contrast to wild type, B(-/-) animals did not demonstrate cellular infiltration, epithelial metaplasia and obstruction of airways following anti-MHC. Frequency of K-α1 tubulin and CollagenV-specific IL-17 cells was significantly decreased in B(-/-) mice. As expected, Abs against self-antigens and germinal center formation were not developed in B(-/-) mice. Thus, we conclude that B cells and its antigen presenting capacity play an important role in induction of immune responses to self-antigens and immunopathogenesis of OAD following the administration of anti-MHC. Therefore, strategies to block B-cell and its antigen presenting functions should be considered for preventing the development of chronic rejection.

Meta-analysis: diagnostic medical radiation exposure in inflammatory bowel disease

BACKGROUND

Diagnostic imaging plays a pivotal role in the diagnosis and management of inflammatory bowel disease (IBD); however, increasing use has led to concerns about the malignant potential of ionising radiation. Several studies have demonstrated that diagnostic imaging can result in exposure to potentially harmful levels of ionising radiation in IBD patients.

AIM

To determine the pooled prevalence of increased exposure and pooled odds ratio of risk factors associated with exposure to potentially harmful levels of diagnostic medical radiation.

METHODS

We searched Medline, EMBASE, CINHAL and reference lists of identified articles, without language restrictions in October 2011.

RESULTS

Six studies with 1704 participants provided data on the proportion of patients receiving potentially harmful levels of radiation defined as ≥50 milli-sieverts (mSv)-equivalent to 5 CT abdomen scans. The pooled prevalence was 8.8% (95% CI 4.4-16.8) for IBD patients and 11.1% (95% CI 5.7-20.5%) and 2% (95% CI 0.8-4.9%) for Crohn's disease and ulcerative colitis patients respectively. Five studies involving 2627 participants provided data for risk factors. IBD-related surgery and corticosteroid use were significant with pooled adjusted odds ratio of 5.4 (95% CI 2.6-11.2) and 2.4 (95% CI 1.7-3.4) respectively.

CONCLUSIONS

About 1 in 10 patients may be exposed to potentially harmful levels of diagnostic medical radiation. Corticosteroid use and IBD related surgery increased this risk. Strategies to reduce radiation exposure while assessing disease activity need to be considered.

Orthopaedic surgeons: as strong as an ox and almost twice as clever? Multicentre prospective comparative study

OBJECTIVE

To compare the intelligence and grip strength of orthopaedic surgeons and anaesthetists.

DESIGN

Multicentre prospective comparative study.

SETTING

Three UK district general hospitals in 2011.

PARTICIPANTS

36 male orthopaedic surgeons and 40 male anaesthetists at consultant or specialist registrar grade.

MAIN OUTCOME MEASURES

Intelligence test score and dominant hand grip strength.

RESULTS

Orthopaedic surgeons had a statistically significantly greater mean grip strength (47.25 (SD 6.95) kg) than anaesthetists (43.83 (7.57) kg). The mean intelligence test score of orthopaedic surgeons was also statistically significantly greater at 105.19 (10.85) compared with 98.38 (14.45) for anaesthetists.

CONCLUSIONS

Male orthopaedic surgeons have greater intelligence and grip strength than their male anaesthetic colleagues, who should find new ways to make fun of their orthopaedic friends.

Exposure to hookworms in patients with Crohn's disease: a case-control study

BACKGROUND

Helminths have been used to inhibit intestinal inflammation in patients with Crohn's disease.

AIM

This study was undertaken to determine if there is a protective association of prior hookworm infection with Crohn's disease, in a region where there is epidemiological transition from parasitic and infectious diseases to increased auto-inflammatory diseases.

METHODS

Hookworm exposure was assessed by peripheral blood mononuclear cell (PBMC) activation by hookworm antigens in 78 patients with Crohn's disease and 75 healthy control participants. The change in proportion of T cells exhibiting CD69 after exposure to crude hookworm antigens was measured. Interferon-γ ELISPOT response to a panel of six recombinant hookworm antigens was analysed.

RESULTS

Patients with Crohn's disease were more often from an urban background (P=0.005) compared to controls, while their socioeconomic status was not significantly different. T cell activation (increase in CD3(+) CD69(+) population) by hookworm antigen was significantly higher in controls compared to Crohn's disease patients (P=0.017), while activation by the nonspecific mitogen phytohemagglutinin was similar in both groups. Circulating T memory cells (CD3(+) CD45RO(+)) after exposure to hookworm antigens were not significantly different between the two groups. Mirroring these changes, interferon-γ ELISPOT responses to hookworm antigens were seen in 36 of 75 controls compared to 20 of 78 Crohn's disease patients (Fisher's exact P=0.005). Multivariate analysis indicated that CD3CD69 shifts (P=0.019), ELISPOT reactivity (P=0.039) and place of residence (P=0.024) were all independently associated with Crohn's disease.

CONCLUSION

The inverse association between Crohn's disease and hookworm antigen reactivity is consistent with the hygiene hypothesis, but requires further exploration.

Density functional theory studies on ice nanotubes

The structure and stability of quasi one-dimensional (1D) ice nanotubes (INTs) have been investigated using Density Functional Theory (DFT) based Becke's three parameter Lee-Yang-Parr exchange and correlation functional (B3LYP) method employing various basis sets. Four different INTs, namely, (4,0)-INT, (5,0)-INT, (6,0)-INT, and (8,0)-INT with different lengths have been considered in this study. The calculated stabilization energies (SEs) illustrate that the stability of INT is proportional to its length and diameter. Further, the encapsulation of various gas molecules (CO(2), N(2)O, CO, N(2), and H(2)) inside the INTs has also been investigated. The calculated SEs of different endohedral complexes reveal that all these gas molecules are stable inside the tubes. The Bader's theory of atoms in molecule (AIM) has been used to characterize intra- and inter-ring H-bonding interactions. The electron density topological parameters derived from AIM theory brings out the difference between the intra- and inter-ring H-bonds of INTs.

C60-fullerene binds with the ATP binding domain of human DNA topoiosmerase II alpha

C60-fullerene has promising biological applications, such as drug delivery, biosensors, diagnosis and theraupetics. Despite of these applications, several in vitro studies have also reported the DNA damaging potential of this nanomaterial. Though, very little is known about the mechanism involved behind the fullerene mediated DNA damage. Our study was aimed at identifying the binding site of fullerene in the ATP binding domain of human topoisomerase II alpha, a major enzyme involved in maintaining DNA topology. In silico studies of fullerene with the enzyme demonstrated that it can interact with the active site residues of this enzyme through hydrophobic, pi-stacking and van der Waals interactions and could inhibit the activity of this enzyme.