Association of Toll-like receptor 4 with hepatitis A virus infection in Assam

Hepatitis A virus (HAV) which causes liver disease is recognized by Toll-like receptors (TLRs) through the viral nucleic acid, initiating the host defense response. The study aims to analyze the role of TLR4 rs11536889 polymorphism in the pathogenesis of hepatitis A cases from Assam. There was significant correlation between TLR4 SNP G/C (rs11536889) and between acute viral hepatitis (AVH) A cases and controls. The correlation of the 3 different genotypes GG, GC and CC of TLR4 rs11536889 with the TLR4 mRNA expression level in all the HAV cases groups have been found to be statistically significant (p <0.001). TLR4 expression was most significantly upregulated in the acute HAV cases, HAV with cholestasis cases and even the HAV caused fulminant hepatitis failure (FHF) cases with the CC genotype of TLR4 rs11536889. The upregulation is mostly seen in the cases with the CC genotype of TLR4 rs11536889 and thus indicates that the mutant variant of TLR4 rs11536899 (CC) may have an effect on the expression of TLR4 at the transcription level. Our study did not show any significant association between AVH and HAV caused FHF (p = 0.32, OR = 0; p = 0.59, OR = 2.06 at 95% CI) among the genotypes GG, GC and CC. Our data suggest that TLR4 gene polymorphism rs11536889 may play a prominent role in HAV disease susceptibility and TLR4 expression in population from Assam.

Exercise training-induced modification of the gut microbiota persists after microbiota colonization and attenuates the response to chemically-induced colitis in gnotobiotic mice

Exercise reduces the risk of inflammatory disease by modulating a variety of tissue and cell types, including those within the gastrointestinal tract. Recent data indicates that exercise can also alter the gut microbiota, but little is known as to whether these changes affect host function. Here, we use a germ-free (GF) animal model to test whether exercise-induced modifications in the gut microbiota can directly affect host responses to microbiota colonization and chemically-induced colitis. Donor mice (n = 19) received access to a running wheel (n = 10) or remained without access (n = 9) for a period of six weeks. After euthanasia, cecal contents were pooled by activity treatment and transplanted into two separate cohorts of GF mice. Two experiments were then conducted. First, mice were euthanized five weeks after the microbiota transplant and tissues were collected for analysis. A second cohort of GF mice were colonized by donor microbiotas for four weeks before dextran-sodium-sulfate was administered to induce acute colitis, after which mice were euthanized for tissue analysis. We observed that microbial transplants from donor (exercised or control) mice led to differences in microbiota β-diversity, metabolite profiles, colon inflammation, and body mass in recipient mice five weeks after colonization. We also demonstrate that colonization of mice with a gut microbiota from exercise-trained mice led to an attenuated response to chemical colitis, evidenced by reduced colon shortening, attenuated mucus depletion and augmented expression of cytokines involved in tissue regeneration. Exercise-induced modifications in the gut microbiota can mediate host-microbial interactions with potentially beneficial outcomes for the host.

Refractive index variation in a free-standing diamond thin film induced by irradiation with fully transmitted high-energy protons

Ion irradiation is a widely employed tool to fabricate diamond micro- and nano-structures for applications in integrated photonics and quantum optics. In this context, it is essential to accurately assess the effect of ion-induced damage on the variation of the refractive index of the material, both to control the side effects in the fabrication process and possibly finely tune such variations. Several partially contradictory accounts have been provided on the effect of the ion irradiation on the refractive index of single crystal diamond. These discrepancies may be attributable to the fact that in all cases the ions are implanted in the bulk of the material, thus inducing a series of concurrent effects (volume expansion, stress, doping, etc.). Here we report the systematic characterization of the refractive index variations occurring in a 38 µm thin artificial diamond sample upon irradiation with high-energy (3 MeV and 5 MeV) protons. In this configuration the ions are fully transmitted through the sample, while inducing an almost uniform damage profile with depth. Therefore, our findings conclusively identify and accurately quantify the change in the material polarizability as a function of ion beam damage as the primary cause for the modification of its refractive index.

High risk of post-infectious irritable bowel syndrome in patients with Clostridium difficile infection

BACKGROUND

Infectious enteritis is a commonly identified risk factor for irritable bowel syndrome (IBS). The incidence of Clostridium difficile infection (CDI) is on the rise. However, there is limited information on post-infectious IBS (PI-IBS) development following CDI and the host- and infection-related risk factors are not known.

AIM

To determine the incidence and risk factors for PI-IBS following CDI.

METHODS

A total of 684 cases of CDI identified from September 2012 to November 2013 were surveyed. Participants completed the Rome III IBS questionnaire and details on the CDI episode. Predictive modelling was done using logistic regression to evaluate risk factors for PI-IBS development.

RESULTS

A total of 315 CDI cases responded (46% response rate) and 205 were at-risk (no pre-CDI IBS) for PI-IBS development. A total of 52/205 (25%) met the Rome III criteria for IBS ≥6 months following CDI. IBS-mixed was most common followed by IBS-diarrhoea. In comparison to those without subsequent PI-IBS, greater percentage of PI-IBS patients had CDI symptoms >7 days, nausea, vomiting, abdominal pain during CDI, anxiety and a higher BMI. Using logistic regression, CDI symptoms >7 days [Odds ratio (OR): 2.96, P = 0.01], current anxiety (OR: 1.33, P < 0.0001) and a higher BMI (OR: 1.08, P = 0.004) were independently associated with PI-IBS development; blood in the stool during CDI was protective (OR: 0.44, P = 0.06).

CONCLUSIONS

In this cohort study, new-onset IBS is common after CDI. Longer CDI duration, current anxiety and higher BMI are associated with the diagnosis of C. difficile PI-IBS. This chronic sequela should be considered during active management and follow-up of patients with CDI.

Oxidative stress: key player in gastrointestinal complications of diabetes

Gastrointestinal dysmotility presenting as nausea, vomiting, bloating, diarrhea, constipation or abdominal pain is seen in diabetic patients. Oxidative stress has recently been recognized as a significant player in the pathogenesis of gastrointestinal complications of diabetes. In this issue of Neurogastroenterology and Motility, a team of investigators from Emory University led by Dr. Srinivasan present new evidence on the effect of oxidative stress in the diabetic colon. They show in diabetic patients, increased oxidative stress is associated with loss of the inhibitory neuronal subpopulation of enteric neurons, and that the neuronal loss can be reversed in-vitro by anti-oxidant lipoic acid. This new information adds to the accumulating evidence on the deleterious effect of oxidative stress in the gastrointestinal tract and highlights the opportunity to develop newer therapies focused on augmenting anti-oxidant defenses in the gastrointestinal tract in diabetic patients.

Magnetic resonance imaging anatomy of the anal canal

The anatomy of the anal canal is complex but well demonstrated by MRI. Understanding the anatomy is a prerequisite for determining the true site and the extent of pathology, especially for surgical workup. In this article, the MRI anatomy of the anal canal has been displayed using highlighted MRI images and line diagrams.

Osteogenic pulmonary metastases originating from a phyllodes tumour of the breast with osteosarcomatous differentiation

Malignant phyllodes tumour is an uncommon breast neoplasm which undergoes osteosarcomatous differentiation in 1.3% of cases. We document the plain film, CT and scintigraphic features of a case of pulmonary metastases from this rare primary tumour.

Antroduodenal manometry in children and adults with severe non-ulcer dyspepsia

BACKGROUND

Nonulcer dyspepsia is common in adults but has been recognized only recently in children.

METHODS

We compared signs, symptoms, and antroduodenal motility findings in 34 children and 35 adults with severe nonulcer dyspepsia.

RESULTS

Symptoms and signs were similar in the two groups. Ten children (29%) and one adult (3%) required tube feedings (p = 0.01). Abdominal surgery had been performed on 6 of 34 (18%) children and 18 of 35 adults (51%) (p < 0.01), without relief of symptoms. Esophageal manometry was abnormal in 5 of 23 (22%) children and 6 of 31 (19%) adults. Antroduodenal manometry was suggestive of neuropathy in 25 children and 26 adults and of myopathy in 3 children and 2 adults. Absence of phase 3 of the migrating motor complex was found in 4 children and 17 adults (p = 0.01). Antroduodenal manometry was normal in six children and seven adults.

CONCLUSION

Signs, symptoms, and discrete manometric abnormalities of childhood nonulcer dyspepsia resembled those of adult nonulcer dyspepsia. Manometric findings in nonulcer dyspepsia resembled those reported in chronic intestinal pseudo-obstruction, suggesting that these conditions are on a continuum of enteric neuromuscular diseases.