Transcriptional regulators transforming growth factor-β1 and estrogen-related receptor-α identified as putative mediators of calf rumen epithelial tissue development and function during weaning

Molecular mechanisms regulating rumen epithelial development remain largely unknown. To identify gene networks and regulatory factors controlling rumen development, Holstein bull calves (n=18) were fed milk replacer only (MRO) until 42 d of age. Three calves each were euthanized at 14 and 42 d of age for tissue collection to represent preweaning, and the remaining calves were provided diets of either milk replacer + orchard grass hay (MH; n=6) to initiate weaning without development of rumen papillae, or milk replacer + calf starter (MG; n=6) to initiate weaning and development of rumen papillae. At 56 and 70 d of age, 3 calves from the MH and MG groups were euthanized for collection of rumen epithelium. Total RNA and protein were extracted for microarray analysis and to validate detected changes in selected protein expression, respectively. As expected, calves fed MRO had no rumen papillae and development of papillae was greater in MG versus MH calves. Differentially expressed genes between the MRO diet at d 42 (preweaning) versus the MG or MH diets at d 56 (during weaning) were identified using permutation analysis of differential expression. Expression of 345 and 519 transcripts was uniquely responsive to MG and MH feeding, respectively. Ingenuity Pathway Analysis (Qiagen, Redwood City, CA) indicated that the top-ranked biological function affected by the MG diet was the cell cycle, and TFGB1, FBOX01, and PPARA were identified as key transcriptional regulators of genes responsive to the MG diet and associated with development of rumen papillae. Increased expressions of TGFB1 mRNA and protein in response to the MG diet were confirmed by subsequent analyses. The top-ranking biological function affected by the MH diet was energy production. Receptors for IGF-1 and insulin, ESRRA, and PPARD were identified by ingenuity pathway analysis as transcriptional regulators of genes responsive to the MH diet. Further analysis of TGFB1 and ESRRA mRNA expression in rumen epithelium obtained from a separate ontogenic study of Holstein calves (n=26) euthanized every 7d from birth to 42 d of age showed increases in transcript expression with advancing age, supporting their roles in mediating rumen epithelial development and function during weaning. Additional evaluation of gene expression in the rumen epithelium of adult cows ruminally infused with butyrate also suggested that observed changes in ESRRA mRNA expression in developing calf rumen may be mediated by increased butyrate concentration. Our results identify TGFB1 and ESRRA as likely transcriptional regulators of rumen epithelial development and energy metabolism, respectively, and provide targets for modulation of rumen development and function in the growing calf.

Heterogeneity of mucosal mast cell infiltration in subgroups of patients with esophageal chest pain

BACKGROUND

Although there is growing evidence that an increase in mucosal mast cells (MMCs) in the small and large intestine is associated with visceral hypersensitivity, few studies have evaluated MMCs in humans with esophageal symptoms. The aim of this study was to investigate esophageal MMC distribution in patients with non-cardiac chest pain (NCCP) and to examine the association between the number of gut MMCs and other functional gastrointestinal disorders.

METHODS

Forty-two consecutive NCCP patients and 10 healthy controls completed a questionnaire for bowel symptoms, chest pain intensity score, and psychologic depression. Esophageal, duodenal, and rectal MMCs were identified immunohistochemically and quantified by image analysis.

KEY RESULTS

Numbers of MMCs were significantly higher in NCCP patients vs healthy controls (11.8 ± 5.6 vs 7.6 ± 3.7 MMCs/high-power field, p = 0.026). In comparison of subgroups classified by 24-h impedance-pH monitoring, esophageal MMC counts were highest in the hypersensitive esophagus group (p < 0.01) and were also significantly increased in the functional chest pain group (p < 0.05). A positive correlation between esophageal and duodenal MMC counts was observed in patients with functional dyspepsia (FD; Spearman ρ = 0.604, p = 0.037). In particular, patients with clinical overlap with irritable bowel syndrome showed a strong positive correlation between esophageal and rectal MMC numbers (Spearman ρ = 0.857, p = 0.010).

CONCLUSIONS & INFERENCES

Among NCCP patients, increased MMC infiltration occurs in subgroups with hypersensitive esophagus and functional chest pain. In subpopulations with overlap with FD or irritable bowel syndrome, esophageal MMC counts demonstrated significant positive correlations with duodenal or rectal MMC counts.

Time domain simulation of tandem silicon solar cells with optimal textured light trapping enabled by the quadratic complex rational function

Amorphous silicon/crystalline silicon (a-Si/c-Si) micromorph tandem cells, with best confirmed efficiency of 12.3%, have yet to fully approach their theoretical performance limits. In this work, we consider a strategy for improving the light trapping and charge collection of a-Si/c-Si micromorph tandem cells using random texturing with adjustable short-range correlations and long-range periodicity. In order to consider the full-spectrum absorption of a-Si and c-Si, a novel dispersion model known as a quadratic complex rational function (QCRF) is applied to photovoltaic materials (e.g., a-Si, c-Si and silver). It has the advantage of accurately modeling experimental semiconductor dielectric values over the entire relevant solar bandwidth from 300-1000 nm in a single simulation. This wide-band dispersion model is then used to model a silicon tandem cell stack (ITO/a-Si:H/c-Si:H/silver), as two parameters are varied: maximum texturing height h and correlation parameter f. Even without any other light trapping methods, our front texturing method demonstrates 12.37% stabilized cell efficiency and 12.79 mA/cm² in a 2 μm-thick active layer.

Esophageal mucosal mast cell infiltration and changes in segmental smooth muscle contraction in noncardiac chest pain

Mast cells release potent mediators that alter enteric nerve and smooth muscle functions and may contribute to the pathogenesis of functional gastrointestinal disorders. The goal of this study was to determine if mucosal mast cell infiltration was associated with smooth muscle segmental changes in esophageal contraction. All patients with noncardiac chest pain (NCCP) were divided into two groups consisting of patients with non-erosive reflux disease or functional chest pain (FCP) according to the results of ambulatory 24 hours esophageal pH monitoring and high-resolution manometry. Pressure-volume (PV) was calculated by multiplying the length of the esophageal segment, duration of the contraction, and mean pressure over the entire space-time box (P mean). Quantification of mast cells was performed in five consecutive nonoverlapping immunostained sections. Spearman correlation analysis showed that the distal segment PV correlated with the mast cell count in all of the patients combined and in patients with FCP with correlation coefficients of 0.509 and 0.436, respectively (P = 0.004 and P = 0.042). Similar findings were observed for the segmental ratio of distal to proximal smooth muscle PV in all patients and in patients with FCP (correlation coefficients 0.566; P = 0.001 and correlation coefficients 0.525; P = 0.012, respectively). Mucosal mast cell infiltration was associated with distal esophageal contraction as a key pathophysiologic factor of NCCP.

Abstract P3-13-09: Relative dose intensity of taxane-based chemotherapy in patients with stage IV breast cancer

Background: Maintaining high relative dose intensity (RDI) has been associated with improved disease-free survival, progression-free survival, and overall survival of patients with breast cancer treated in the adjuvant setting. Neutropenia and related complications, such as febrile neutropenia, are common side effects of myelosuppressive chemotherapy that can lead to dose delays, dose reductions, and reduced RDI. Primary prophylaxis with colony-stimulating factors (CSFs) can reduce the duration and severity of neutropenia and the incidence of febrile neutropenia, thereby supporting high RDI. For patients with stage IV breast cancer, dose delays and dose reductions are frequently used to manage toxicity associated with myelosuppressive chemotherapy. However, the prevalence and impact of reduced RDI in the metastatic disease setting is poorly understood.

Objective: To estimate mean chemotherapy RDI and incidences of dose delays, dose reductions, RDI &lt;85%, and primary CSF prophylaxis among women with stage IV breast cancer receiving first-line chemotherapy.

Methods: Using the McKesson Specialty Health/US Oncology iKnowMed™ electronic health record (HER) database, we retrospectively identified adult women with stage IV breast cancer who initiated first-line, intravenous, myelosuppressive chemotherapy from January 2007 to December 2010 in community oncology practices in the US. Patients were assigned to chemotherapy cohorts based on myelosuppressive agents received in cycle 1 and planned regimen information in the database. Standard chemotherapy regimens were defined based on NCCN breast cancer guidelines and clinical studies. Mean RDI and incidences of dose delays ≥7 days, dose reductions ≥15%, and RDI &lt;85% in any cycle during the course of chemotherapy were evaluated relative to the standard chemotherapy regimen. Primary CSF prophylaxis was defined as first receipt of CSF during the first 5 days of chemotherapy cycle 1. Patients were followed for up to 6 months after chemotherapy initiation.

Results: This study included 1471 patients with stage IV breast cancer who received myelotoxic chemotherapy. The most common chemotherapy regimens in the metastatic setting were taxane-based, and endpoints for the three most common chemotherapy regimens (n = 307) are shown in the Table.

 Paclitaxel/ BevacizumabaAlbumin-bound PaclitaxelbPaclitaxelcN1767556Age, mean (SD) years58.2 (11.9)63.6 (12.4)61.8 (13.8)RDI, mean (SE)89.0% (1.9)89.1% (3.1)89.0% (3.2)RDI &lt;85%37.5%41.3%26.8%Dose delays ≥7 days36.9%22.7%32.1%Dose reductions ≥15%40.9%61.3%8.9%CSF primary prophylaxis0%1.3%3.6%aPaclitaxel 80-90 mg/m2 on days 1, 8, and 15 and bevacizumab 10 mg/kg on days 1 and 15 (cycle length 28 days). Paclitaxel dose at cycle 1, day 1 was defined as the standard dose for this regimen; bAlbumin-bound paclitaxel 100 mg/m2 on days 1, 8, and 15 (cycle length 28 days); cPaclitaxel 80 mg/m2 (cycle length 7 days).

Conclusions: Chemotherapy dose delays, dose reductions, and reduced RDI were common in patients with stage IV breast cancer. The impact of RDI on progression-free and overall survival is being evaluated and will be presented.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-13-09.

Photodynamic therapy plus regulatory T-cell depletion produces immunity against a mouse tumour that expresses a self-antigen

Background:

Photodynamic therapy (PDT) can lead to development of antigen-specific immune response and PDT-mediated immunity can be potentiated by T regulatory cell (Treg) depletion. We investigated whether the combination of PDT with cyclophosphamide (CY) could foster immunity against wild-type tumours expressing self-antigen (gp70).

Methods:

Mice with CT26 tumours were treated with PDT alone or in combination with low-dose CY. T regulatory cell numbers and transforming growth factor-β (TGF-β) levels were measured at several time points after treatment. Mice cured by PDT+CY were rechallenged with CT26 and monitored for long-term survival.

Results:

Photodynamic therapy+CY led to complete tumour regression and long-term survival in 90% of treated mice while the absolute numbers of Treg decreased after PDT+CY and the TGF-β levels were reduced to a level comparable to naïve mice. Sixty-five percent of the mice treated with PDT+CY that survived over 90 days tumour free rejected the rechallenge with the same tumour when a second dose of CY was administered before rechallenge but not without.

Conclusion:

Administration of CY before PDT led to depletion of Treg and potentiated PDT-mediated immunity, leading to long-term survival and development of memory immunity that was only uncovered by second Treg depletion.

The effects of statins on the clinical outcomes of Clostridium difficile infection in hospitalised patients

BACKGROUND

An association between exposure to statin drugs and favourable treatment outcomes for various types of infections has been established.

AIM

To determine the clinical characteristics and treatment outcomes of Clostridium difficile infection (CDI) among hospitalised patients taking statin drugs.

METHODS

The medical records were reviewed for consecutive in-patients with CDI confirmed by positive toxin assay (A or B), C. difficile culture, or the presence of pseudomembrane on endoscopy. Treatment success was defined as the resolution of diarrhoea within 6 days of therapy. The primary end points were assessed by average symptom recovery time and treatment response (success or failure).

RESULTS

Among 949 patients, the overall response to metronidazole was 91.9%. The baseline characteristics showed some differences between statin users and statin non-users with respect to mean disease severity score. In the multivariate analysis, successful treatment response was significantly associated with the absence of exposure to proton pump inhibitors (PPIs) (OR = 0.690, 95% CI = 0.513-0.929, P = 0.014) and with exposure to statins (OR = 1.449, 95% CI = 1.015-2.070, P = 0.041). Contrary to the treatment response, univariate and multivariate analyses failed to show that exposure to PPIs or statins affected symptom recovery times. Sixty-day CDI recurrence rates for those patients with statin exposure were significantly lower compared with those patients without statin exposure (3% vs. 7.3%, respectively; RR = 0.393, 95% CI = 0.167-0.926, P = 0.033).

CONCLUSION

Prior statin exposure in patients with C. difficile infection is associated with a successful response to treatment.

Measurement of muon neutrino quasielastic scattering on a hydrocarbon target at Eν ~ 3.5 GeV

We report a study of ν(μ) charged-current quasielastic events in the segmented scintillator inner tracker of the MINERvA experiment running in the NuMI neutrino beam at Fermilab. The events were selected by requiring a μ- and low calorimetric recoil energy separated from the interaction vertex. We measure the flux-averaged differential cross section, dσ/dQ², and study the low energy particle content of the final state. Deviations are found between the measured dσ/dQ² and the expectations of a model of independent nucleons in a relativistic Fermi gas. We also observe an excess of energy near the vertex consistent with multiple protons in the final state.

Measurement of muon antineutrino quasielastic scattering on a hydrocarbon target at Eν ~ 3.5 GeV

We have isolated ν(μ) charged-current quasielastic (QE) interactions occurring in the segmented scintillator tracking region of the MINERvA detector running in the NuMI neutrino beam at Fermilab. We measure the flux-averaged differential cross section, dσ/dQ², and compare to several theoretical models of QE scattering. Good agreement is obtained with a model where the nucleon axial mass, M(A), is set to 0.99 GeV/c² but the nucleon vector form factors are modified to account for the observed enhancement, relative to the free nucleon case, of the cross section for the exchange of transversely polarized photons in electron-nucleus scattering. Our data at higher Q² favor this interpretation over an alternative in which the axial mass is increased.