Elevated levels of leukotriene C4 synthase mRNA distinguish a subpopulation of eosinophilic oesophagitis patients

BACKGROUND

Cysteinyl leukotrienes contribute to Th2-type inflammatory immune responses. Their levels in oesophageal tissue, however, do not distinguish patients with eosinophilic oesophagitis (EoE) from controls.

OBJECTIVE

We asked whether mRNA levels of leukotriene C4 synthase (LTC4 S), a key regulator of leukotriene production, could serve as a marker for EoE.

METHODS

Digital mRNA expression profiling (nCounter(®) Technology) was performed on proximal and distal oesophageal biopsies of 30 paediatric EoE patients and 40 non-EoE controls. Expression data were confirmed with RT-qPCR. LTC4 S mRNA levels were quantified in whole blood samples. Leukotriene E4 was measured in urine.

RESULTS

LTC4 S mRNA levels were elevated in proximal (2.6-fold, P < 0.001) and distal (2.9-fold, P < 0.001) oesophageal biopsies from EoE patients. Importantly, increased LTC4 S mRNA transcripts identified a subpopulation of EoE patients (28%). This patient subgroup had higher serum IgE levels (669 U/mL vs. 106 U/mL, P = 0.01), higher mRNA transcript numbers of thymic stromal lymphopoietin (TSLP) (1.6-fold, P = 0.009) and CD4 (1.4-fold, P = 0.04) but lower IL-23 mRNA levels (0.5-fold, P = 0.04). In contrast, elevated levels of IL-23 mRNA were found in oesophageal biopsies of patients with reflux oesophagitis. LTC4 S mRNA transcripts in whole blood and urinary excretion of leukotriene E4 were similar in EoE patient subgroups and non-EoE patients.

CONCLUSION & CLINICAL RELEVANCE

Elevated oesophageal expression of LTC4 S mRNA is found in a subgroup of EoE patients, concomitant with higher serum IgE levels and an oesophageal transcriptome indicative of a more-pronounced allergic phenotype. Together with TSLP and IL-23 mRNA levels, oesophageal LTC4 S mRNA may facilitate diagnosis of an EoE subpopulation for personalized therapy.

Effect of subtype-selective adenosine receptor antagonists on basal or haloperidol-regulated striatal function: studies of exploratory locomotion and c-Fos immunoreactivity in outbred and A(2A)R KO mice

Behavioral activation is regulated by dopamine (DA) in striatal areas. At low doses, while typical antipsychotic drugs produce psychomotor slowing, psychostimulants promote exploration. Minor stimulants such as caffeine, which act as adenosine receptor antagonists, can also potentiate behavioral activation. Striatal areas are rich in adenosine and DA receptors, and adenosine A2A receptors are mainly expressed in the striatum where they are co-localized with DA D2 receptors. Adenosine antagonists with different receptor-selectivity profiles were used to study spontaneous or haloperidol-impaired exploration and c-Fos expression in different striatal areas. Because A2A antagonists were expected to be more selective for reversing the effects of the D2 antagonist haloperidol, A2A receptor knockout (A2ARKO) mice were also assessed. CD1 and A2ARKO male mice were tested in an open field and in a running wheel. Only the A1/A2A receptor antagonist theophylline (5.0-15.0 mg/kg) and the A2A antagonist MSX-3 (2.0 mg/kg) increased spontaneous locomotion and rearing. Co-administration of theophylline (10.0-15.0 mg/kg), and MSX-3 (1.0-3.0 mg/kg) reversed haloperidol-induced suppression of locomotion. The A1 antagonist CPT was only marginally effective in reversing the effects of haloperidol. Although adenosine antagonists did not affect c-Fos expression on their own, theophylline and MSX-3, but not CPT, attenuated haloperidol induction of c-Fos expression. A2ARKO mice were resistant to the behavioral effects of haloperidol at intermediate doses (0.1 mg/kg) in the open field and in the running wheel. A2A receptors are important for regulating behavioral activation, and interact with D2 receptors in striatal areas to regulate neural processes involved in exploratory activity.

Adenosine A2A receptor antagonism and genetic deletion attenuate the effects of dopamine D2 antagonism on effort-based decision making in mice

Brain dopamine (DA) and adenosine interact in the regulation of behavioral activation and effort-related processes. In the present studies, a T-maze task was developed in mice for the assessment of effort-related decision making. With this task, the two arms of the maze have different reinforcement densities, and a vertical barrier is positioned in the arm with the higher density (HD), presenting the animal with an effort-related challenge. Under control conditions mice prefer the HD arm, and climb the barrier to obtain the larger amount of food. The DA D(2) receptor antagonist haloperidol decreased selection of the HD arm and increased selection of the arm with the low density of reinforcement. However, the HD arm was still the preferred choice in haloperidol-treated mice trained with barriers in both arms. Pre-feeding the mice to reduce food motivation dramatically increased omissions, an effect that was distinct from the actions of haloperidol. Co-administration of theophylline, a nonselective adenosine receptor antagonist, partially reversed the effects of haloperidol. This effect seems to be mediated by the A(2A) receptor but not the A(1) receptor, since the A(2A) antagonist MSX-3, but not the A(1) antagonist CPT, dose dependently reversed the effects of haloperidol on effort-related choice and on c-Fos expression in the dorsal striatum and nucleus accumbens. In addition, adenosine A(2A) receptor knockout mice were resistant to the effects of haloperidol on effort-related choice in the maze. These results indicate that DA D(2) and adenosine A(2A) receptors interact to regulate effort-related decision making and effort expenditure in mice.

The vagus nerve as a regulator of growth hormone secretion

The growth hormone (GH) axis is mainly regulated by the growth hormone releasing hormone (GHRH) and somatostatin (SS) hypothalamic peptides. Nevertheless, since ghrelin peptide was discovered as the natural ligand for growth hormone secretagogue receptor (GHS-R), the mechanism of GH regulation has acquired a new dimension. It was described that ghrelin possesses a relevant effect inducing GH secretion when it is administered peripherally. A role of the vagus nerve mediating ghrelin action has been described although this effect is not understood. Under this context the main objective of this work was to determine the possible involvement of the vagus in the somatotroph axis regulation. The results in this manuscript show that animals with a disruption of the vagus connection presented lower basal IGF-1 and GH levels, a decreased GH response to peripheral GHRH administration and a marked diminution in the GH response to peripheral and central ghrelin treatments. In addition, vagotomized animals showed a down-regulation of GHRH mRNA in the arcuate nucleus of the hypothalamus and a down-regulation in both GHRH and GHS receptors' mRNA at the pituitary level. In conclusion, the present work reveals that the vagus nerve is crucial in growth hormone regulation and essential for the full GH-releasing effect of ghrelin.

Macronutrients act directly on the stomach to regulate gastric ghrelin release

BACKGROUND

Ghrelin is a gastric secreted hormone deeply implicated in meal initiation and body weight regulation. This peptide is a peripheral orexigenic hormone with a nutritional status-dependent regulation showing a pre-pandrial rise and post-prandial fall pattern. A wide variety of studies have tested the effect of meal different nutrient composition over stomach mucosa ghrelin content and plasmatic ghrelin levels; nevertheless, few and non-conclusive data exist about the direct action of macronutrients on the stomach in order to regulate ghrelin secretion. The recent identification of taste receptors or chemoreceptors in the stomach mucosa would reinforce this paradigm.

AIMS

To investigate the individual effect of different macronutrients (l-glutamine, lipids, and glucose) over gastric ghrelin secretion by using an in vitro gastric explants model.

RESULTS

L-glutamine and intralipid emulsion act locally in the stomach decreasing ghrelin secretion, while no effect was found after glucose exposure.

CONCLUSIONS

These results show for the first time that macronutrients, and specially amino acids and lipids, act directly in the stomach in order to regulate gastric ghrelin release. Consequently, the chemosensory capacity of the stomach, until now restricted to the oral cavity or intestine, is demonstrated.

Age, sex, and lactating status regulate ghrelin secretion and GOAT mRNA levels from isolated rat stomach

Ghrelin is a stomach derivate peptide involved in energy homeostasis regulation, and ghrelin O-acyltransferase (GOAT) is the enzyme responsible for ghrelin acylation. Puberty is a period characterized by profound changes in the metabolic requirements and notable variations of sexual hormone levels. On the other hand, the weaning process is a fundamental modification of the diet, which implicates several adaptations of the gastrointestinal tract physiology. Until now the direct secretion of ghrelin by the stomach in these conditions, without interferences from other organs, has never been studied. The main objective of this article was to investigate how the stomach modulates ghrelin production and secretion as well as GOAT expression on these periods of life. Gastric ghrelin secretion is regulated through postnatal life in an independent way of gastric expression and circulating levels of this hormone. The present work shows a strong regulation of gastric ghrelin secretion by estrogens. The weaning strongly regulates gastric ghrelin secretion. Animals subjected to delayed weaning present a lower body weight than the corresponding controls. For the first time, it is shown that a noticeable decrease in circulating levels of testosterone and estrogens is associated with delay of weaning. GOAT mRNA levels in the stomach are strongly regulated by age, breastfeeding, and testosterone. In conclusion, the stomach itself regulates ghrelin and GOAT production to adapt the organism to the metabolic requirements demanded through each stage of life.

The 1985 central chile earthquake: a repeat of previous great earthquakes in the region?

A great earthquake (surface-wave magnitude, 7.8) occurred along the coast of central Chile on 3 March 1985, causing heavy damage to coastal towns. Intense foreshock activity near the epicenter of the main shock occurred for 11 days before the earthquake. The aftershocks of the 1985 earthquake define a rupture area of 170 by 110 square kilometers. The earthquake was forecast on the basis of the nearly constant repeat time (83 +/- 9 years) of great earthquakes in this region. An analysis of previous earthquakes suggests that the rupture lengths of great shocks in the region vary by a factor of about 3. The nearly constant repeat time and variable rupture lengths cannot be reconciled with time- or slip-predictable models of earthquake recurrence. The great earthquakes in the region seem to involve a variable rupture mode and yet, for unknown reasons, remain periodic. Historical data suggest that the region south of the 1985 rupture zone should now be considered a gap of high seismic potential that may rupture in a great earthquake in the next few tens of years.

Differentiation of the volatile profile of microbiologically contaminated canned tomatoes by dynamic headspace extraction followed by gas chromatography-mass spectrometry analysis

The aromatic profile of microbiologically contaminated canned tomatoes was analyzed by the dynamic headspace extraction technique coupled with gas chromatography-mass spectrometry. Canned tomatoes contaminated with Escherichia coli, Saccharomyces cerevisiae and Aspergillus carbonarius were analyzed after 2 and 7 days. About 100 volatiles were detected, among which alcohols, aldehydes and ketones were the most abundant compounds. Gas chromatographic peak areas were used for statistical purposes. First, principal component analysis was carried out in order to visualize data trends and clusters. Then, linear discriminant analysis was performed in order to detect the set of volatile compounds ables to differentiate groups of analyzed samples. Five volatile compounds, i.e. ethanol, beta-myrcene, o-methyl styrene, 6-methyl-5-hepten-2-ol and 1-octanol, were found to be able to better discriminate between uncontaminated and contaminated samples. Prediction ability of the calculated model was estimated to be 100% by the "leave-one-out" cross-validation. An electronic nose device was then used to analyze the same contaminated and not contaminated canned tomato samples. Preliminary results were compared with those obtained by dynamic headspace gas chromatography-mass spectrometry, showing a good agreement.

The role of genomic and antigenomic HCV-RNA strands as predictive factors of response to pegylated interferon plus ribavirin therapy

BACKGROUND

Hepatitis C virus replicates by the synthesis of an antigenomic HCV-RNA. As the end point of anti-viral therapy is to decrease viral replication, the amount of antigenomic HCV-RNA could influence the response.

AIM

To study if amounts of genomic and antigenomic HCV-RNA in the baseline liver biopsy are predictive factors of response to anti-viral therapy.

METHODS

Eighty-eight patients with chronic HCV infection (anti-HIV-negative) treated with pegyltaed-interferon-alpha2b plus ribavirin for 12 months were included. Intrahepatic genomic and antigenomic HCV-RNA concentrations were determined by real-time polymerase chain reaction and percentage of infected hepatocytes by in situ hybridization.

RESULTS

Of the 88 patients, 31% were responders while 69% were not. Median of antigenomic HCV-RNA in liver of responders and non-responders was 120 000 copies/microg RNA (range: 10,000-775,000) vs. 150,000 copies/microg RNA (range: 100-3,200,000; P = 0.38). Median of genomic HCV-RNA in liver of responders was 1,250,000 copies/microg RNA (range: 5000-9,000,000) and in non-responders 3,180,000 copies/microg RNA (range: 4600-18,000,000; P = 0.0191). Predictive factors of response in the logistic regression were: intrahepatic amount of genomic HCV-RNA, percentage of infected hepatocytes and previous therapy.

CONCLUSION

Response to 12 months of therapy with pegylated interferon-alpha2b plus ribavirin depends on the amount of genomic HCV-RNA in the pre-treatment liver biopsy.

Tumor inflamatorio miofibroblástico pulmonar

Myofibroblastic inflammatory tumor is a controversial entity that shows great variability in clinical presentation, histological findings, evolution, and prognosis. It is a rare cause of primary lung tumor in adults; however, it is the most common cause of lung tumors in children. The diagnosis is fundamentally histological, although histological diagnosis is not easy because myofibroblastic inflammatory tumor is characterized by a polymorphic cellular infiltration of variable cellular composition that could be similar to other diseases such as lymphoma or low-grade sarcoma. We report the case of a 23-year-old woman in whom a solitary pulmonary nodule was discovered incidentally at plain-film chest x-ray.

Comparative study between occult hepatitis C virus infection and chronic hepatitis C

We have recently described the presence of occult hepatitis C virus (HCV) infection (HCV-RNA in liver in the absence of anti-HCV and serum HCV-RNA) in patients with persistently abnormal liver function tests of unknown aetiology. The aim of this study was to compare the characteristics of patients with occult HCV infection vs those of patients with chronic hepatitis C. We compared clinical features of 68 patients with occult HCV infection and 69 untreated chronic HCV patients (anti-HCV and serum HCV-RNA positive), matched for age, gender, duration of abnormal liver function tests and body mass index. Aspartate aminotransferase and alanine aminotransferase were higher (P < 0.001) in chronic HCV, but cholesterol and triglycerides were significantly higher in patients with occult HCV infection (P < 0.001 and P = 0.002). Chronic HCV patients had higher gamma-globulin (P = 0.005), alpha-foetoprotein (P < 0.001) and iron (P < 0.001) levels. Percentage of patients with necroinflammatory activity and fibrosis was higher (P < 0.001) in chronic HCV than in occult HCV infection. Mean percentage of infected hepatocytes was higher (P = 0.001) in chronic HCV (10.1%) than in occult HCV infection (5.3%). This occult HCV infection is a milder disease than chronic HCV, and this could be related to the significantly lower number of infected hepatocytes observed in occult HCV.

Effect of anti-viral therapy for occult hepatitis C virus infection

BACKGROUND

Occult hepatitis C virus infection is defined by the presence of hepatitis C virus-RNA in liver but with undetectable anti-hepatitis C virus and serum viral RNA.

AIM

To study the response to anti-viral therapy in occult hepatitis C virus infection to assess the pathogenic effect of occult hepatitis C virus.

METHODS

Ten patients with occult hepatitis C virus infection were treated with pegylated-interferon plus ribavirin for 24 weeks and were followed-up 24 weeks after therapy. All patients had abnormal alanine aminotransferase, hepatitis C virus-RNA positive in peripheral blood mononuclear cells and liver necroinflammation.

RESULTS

At the end of treatment and follow-up, the percentage of patients with normal alanine aminotransferase was 80% (95% CI: 48-96%) and 60% (95% CI: 31-84%) respectively, and hepatitis C virus-RNA in peripheral blood mononuclear cells was negative in 80% (95% CI: 48-96%) and 70% (95% CI: 40-90%) cases. At the end of follow-up sustained response was observed in 30% (95% CI: 11-61%) of cases. Five patients underwent a second liver biopsy. In all cases, liver hepatitis C virus-RNA persisted, although hepatitis C virus-RNA load was significantly lower (3.2 x 10(4) +/- 5.1 x 10(4) copies/microg RNA) than in the basal biopsy (2.4 x 10(5) +/- 3.8 x 10(5) copies/microg RNA); (P = 0.043). Necroinflammation and fibrosis decreased in three cases.

CONCLUSION

The biochemical, virological and histological response to therapy achieved in patients with occult hepatitis C virus infection demonstrates the pathologic effects of occult hepatitis C virus.

Hepatitis C virus (HCV) and hepatitis B virus (HBV) can coinfect the same hepatocyte in the liver of patients with chronic HCV and occult HBV infection

In this work, we have shown that hepatitis C virus (HCV) and hepatitis B virus (HBV) can coexist in the same hepatocyte using double fluorescent in situ hybridization in liver biopsy samples from patients with chronic HCV infection with occult HBV infection. Digital image analysis of hybridization signals showed that the HBV DNA levels in coinfected hepatocytes were lower than those in cells infected only with HBV. This finding supports the hypothesis of inhibition of HBV replication by HCV. Furthermore, HCV RNA levels were lower in coinfected cells than in cells infected only with HCV, suggesting that HBV may also inhibit HCV replication.

Hepatitis C virus replicates in peripheral blood mononuclear cells of patients with occult hepatitis C virus infection

BACKGROUND

Occult hepatitis C virus (HCV) infection is characterised by the presence of HCV-RNA in the liver in the absence of anti-HCV, and serum viral RNA. Up to 70% of these patients also have HCV-RNA in peripheral blood mononuclear cells (PBMC) but it is not known if HCV is replicating in these cells.

AIM

We studied possible HCV replication in PBMC of 18 patients with an occult HCV infection who were selected on the basis of HCV-RNA positivity in PBMC.

METHODS

Detection of HCV-RNA positive and negative strands in PBMC was done by strand specific reverse transcriptase-polymerase chain reaction (RT-PCR) and by in situ hybridisation.

RESULTS

The presence of HCV-RNA positive strand in PBMC was confirmed in all patients by strand specific RT-PCR and by in situ hybridisation. Mean percentage of PBMC which had the HCV-RNA positive strand was 3.3% (95% confidence interval (CI) 2.1-4.4) The HCV-RNA negative strand was found in the PBMC of 11/18 (61%) patients by strand specific RT-PCR and confirmed by in situ hybridisation, and the percentage of PBMC harbouring the HCV-RNA negative strand was 3.1% (95% CI 0.8-5.5). There was a significant correlation (p = 0.001, r = 0.84) between the percentage of PBMC with the HCV-RNA positive strand and that of PBMC with the HCV-RNA negative strand.

CONCLUSION

HCV replicates in the PBMC of patients with occult HCV infection and thus, although these patients do not have serum HCV-RNA, they could be potentially infectious.