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Abstract Background Many polycyclic aromatic hydrocarbons (PAHs) can cause DNA adducts and initiate carcinogenesis. Mixed exposures to coal dust (CD) and PAHs are common in occupational settings. In the CD and PAH-exposed lung, CD increases apoptosis and causes alveolar type II (AT-II) cell hyperplasia but reduces CYP1A1 induction. Inflammation, but not apoptosis, appears etiologically associated with reduced CYP1A1 induction in this mixed exposure model. Many AT-II cells in the CD-exposed lungs have no detectable CYP1A1 induction after PAH exposure. Although AT-II cells are a small subfraction of lung cells, they are believed to be a potential progenitor cell for some lung cancers. Because CYP1A1 is induced via ligand-mediated nuclear translocation of the aryl hydrocarbon receptor (AhR), we investigated the effect of CD on PAH-induced nuclear translocation of AhR in AT-II cells isolated from in vivo-exposed rats. Rats received CD or vehicle (saline) by intratracheal (IT) instillation. Three days before sacrifice, half of the rats in each group started daily intraperitoneal injections of the PAH, β-naphthoflavone (BNF). Results Fourteen days after IT CD exposure and 1 day after the last intraperitoneal BNF injection, AhR immunofluorescence indicated that proportional AhR nuclear expression and the percentage of cells with nuclear AhR were significantly increased in rats receiving IT saline and BNF injections compared to vehicle controls. However, in CD-exposed rats, BNF did not significantly alter the nuclear localization or cytosolic expression of AhR compared to rats receiving CD and oil. Conclusion Our findings suggest that during particle and PAH mixed exposures, CD alters the BNF-induced nuclear translocation of AhR in AT-II cells. This provides an explanation for the modification of CYP1A1 induction in these cells. Thus, this study suggests that mechanisms for reduced PAH-induced CYP1A1 activity in the CD exposed lung include not only the effects of inflammation on the lung as a whole, but also reduced PAH-associated nuclear translocation of AhR in an expanded population of AT-II cells.

The objective of this work was to study the impact of deficiency of certain macro and microelements on clinical, hematobiochemical and electrocardiographic changes in sheep. The survey study was carried out on a total of 300 sheep, of which 250 suffered from mineral deficiency and 50 apparent healthy were used as control. Clinical investigations of diseased sheep revealed change wool color, easily detached wool, alopecia, pale mucous membrane, and diarrhea. Clinical examination showed significant elevation (p< 0.05) of respiratory rate and heart rate. Hematological examination revealed significant (P<0.05) decrease in Hb, RBCs, WBCs and HCT, with increase in MCV, MCH. Biochemically, there was a statistically significant (P<0.05) decline in Ca, Mg, P, Cu, Zn, Se, Fe, TP and albumin, whereas ALT, ALP, LDH, cTnI, and creatinine levels increased significantly (P<0.05). Electrocardiographic examination showed different changes, including abnormal T-waves (wide and enlarged), premature ventricular depolarization and cardiac arrhythmia. It was concluded that macro-micro element deficiency is associated with clinical, biochemical, hematological and ECG alterations. In addition, they have been related to dysfunctions of internal organs including liver, heart and kidney. Therefore, it is recommended to prescribe a proper feeding management program containing the necessary macro- and micro elements for sheep flocks and do not rely only on the grazing as a main source of feed to maintain the health and production of sheep. [ABSTRACT FROM AUTHOR]

In this work, the effects of rotational and traverse speeds on the 1.5 mm butt joint performance of friction stir welded 2024-T4 aluminum alloy sheets have been investigated. Five rotational speeds ranging from 560 to 1800 rpm and five traverse speeds ranging from 11 to 45 mm/min have been employed. The characterization of microstructure and the mechanical properties (tensile, microhardness, and bending) of the welded sheets have been studied. The results reveal that by varying the welding parameters, almost sound joints and high performance welded joints can be successfully produced at the rotational speeds of 900 rpm and 700 rpm and the traverse speed of 35 mm/min. The maximum welding performance of joints is found to be 86.3% with 900 rpm rotational speed and 35 mm/min traverse speed. The microhardness values along the cross-section of the joints show a dramatic drop in the stir zone where the lowest value reached is about 63% of the base metal due to the softening of the welded zone caused by the heat input during joining. [ABSTRACT FROM AUTHOR]

Background: The importance of upper airway structure in the susceptibility of the lower respiratory tract to colonization with potential pathogens is well established. With the advent of rapid, high throughput, next generation sequencing, there is a growing appreciation of the importance of commensal microbial populations in maintaining mucosal health, and a realization that bacteria colonize anatomical locations that were previously considered to be sterile. While upper respiratory tract microbial populations have been described, there are currently no published studies describing the normal microbial populations of the bovine lower respiratory tract. Consequently, we have little understanding of the relationship between upper and lower respiratory tract microbiota in healthy cattle. The primary objective of our study was to characterize the composition, structure and relationship of the lower and upper respiratory microbial communities in clinically healthy feedlot cattle. Nasopharyngeal swabs (NPS), and bronchoalveolar lavage (BAL) fluid, were collected from clinically healthy feedlot calves (n = 8). Genomic DNA from each sample was extracted, and the V3-V4 hypervariable region of the bacterial 16S rRNA gene was amplified and sequenced using Illumina Miseq platform. Results: Across all samples, the most predominant phyla were Proteobacteria, Actinobacteria and Firmicutes. The most common genera were Rathayibacter, Mycoplasma, Bibersteinia and Corynebacterium. The microbial community structure was distinct between these two biogeographical sites. Most of the bacterial genera identified in the BAL samples were also present in the NPS, but biogeographical-specific genera were enriched in both the NPS (Rathayibacter) and BAL (Bibersteinia) samples. There were strong associations between the presence of certain taxa at each specific location, and strong correlations between the presence of specific taxa in both the NPS and BAL samples. Conclusions: The correlation between the presence of specific taxa in both the NPS and BAL samples, supports the notion of a mutualistic interrelationship between these microbial communities. Future studies, in large cohorts of animals, are needed to determine the role and clinical importance of the relationships of respiratory tract microbial communities with health, productivity, and susceptibility to the development of respiratory disease, in growing cattle. [ABSTRACT FROM AUTHOR]

This study was carried out on 15 Holstein cows divided into 3 groups of 5. Group 1 was the control, group 2 had traumatic reticuloperitonitis (TRP), and group 3 had traumatic pericarditis (TP). Comparison between the groups included clinical, hematological, biochemical, and ultrasonographic changes. TRP cows had arched backs, a sharp decrease in milk yield, and a reluctance to move, with abduction of the fore limbs. TP cows had edema of the brisket and submandibular region, with jugular vein distension and pulsation. TRP cows had a significant increase in PCV, leukocytes, and neutrophils, and a significant decrease in RBC, hemoglobin, and lymphocytic counts, as compared to the control group. TP cows had significant erythrocytopenia, leukocytosis, neutrophilia, monocytosis eosinopenia, and basopenia, and a significant decrease in the hemoglobin, lymphocytes, eosinophils, and basophils as compared to the controls. Serum AST, SLT, LDH, and CPK were significantly higher in the TP group than they were in the control and TRP groups. It was concluded that TP cows had more significant changes in hematology, biochemistry, ultrasonography, and histopathology than the TRP cows. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons (PAHs) are products of incomplete combustion that are commonly inhaled by workers in the dusty trades. Many PAHs are metabolized by cytochrome P-4501A1 (CYP1A1), which may facilitate excretion but may activate pulmonary carcinogens. PAHs also stimulate their own metabolism by inducing CYP1A1. Recent studies suggest that respirable coal dust exposure inhibits induction of pulmonary CYP1A1 using the model PAH β-naphthoflavone. The effect of the occupational particulate respirable crystalline silica was investigated on PAH-dependent pulmonary CYP1A1 induction. Male Sprague-Dawley rats were exposed to intratracheal silica or vehicle and then intraperitoneal β-naphthoflavone, a CYP1A1 inducer, and/or phenobarbital, an inducer of hepatic CYP2B1, or vehicle. β-Naphthoflavone induced pulmonary CYP1A1, but silica attenuated this β-naphthoflavone-induced CYP1A1 activity and also suppressed the activity of CYP2B1, the major constituitive CYP in rat lung. The magnitude of CYP activity suppression was similar regardless of silica exposure dose within a range of 5 to 20 mg/rat. Phenobarbital and β-naphthoflavone had no effect on pulmonary CYP2B1 activity. Both enzymatic immunohistochemistry and immunofluorescent staining for CYP1A1 indicated that sites of CYP1A1 induction were nonciliated airway epithelial cells, endothelial cells, and the alveolar septum. Using immunofluorescent colocalization of CYP1A1 with cytokeratin 8, a marker of alveolar type II cells, the proximal alveolar region was the site of both increased alveolar type II cells and decreased proportional CYP1A1 expression in alveolar type II cells. Our findings suggest that in PAH-exposed rat lung, silica is a negative modifier of CYP1A1 induction and CYP2B1 activity. [ABSTRACT FROM AUTHOR]