An assessment of potential exposure to bioaerosols among swine farm workers with particular reference to airborne microorganisms in the respirable fraction under various breeding conditions

The project was aimed at evaluating the potential occupational exposure of swine farm workers to dust and microorganisms present in piggery bioaerosols (especially in its respirable fraction) under various breeding conditions. Sampling was carried out in 14 buildings located at 13 pig breeding and production farms in Poland. Concentrations of inhalable and respirable dusts in the air of the piggeries were low (means, respectively, 1.76 and 0.23 mg/m³). The concentration of microorganisms was generally high (mean = 3.53 × 10⁵ cfu/m³). More than 96% of determined microorganisms were bacteria (mean = 3.42 × 10⁵ cfu/m³). The fungal concentration was distinctly lower (mean = 2.71 × 10³ cfu/m³). The concentration of bacteria in the respirable fraction of bioaerosol (mean = 1.51 × 10⁵ cfu/m³) made up for 48.2% of their total concentration, while the level of fungi in that fraction (mean = 1.50 × 10³ cfu/m³) formed 68.8% of the total fungal concentration. The concentration of inhalable dust was significantly modified by the type of breeding system. The factors that significantly affected the total concentrations of microbes and bacteria, as well as their levels in the bioaerosols’ respirable fraction were as follows: herd size, breeding system, feeding method and the type of ventilation system. In the case of fungi, these were the livestock breeding system and the feeding method. Moreover, there was a high positive correlation of inhalable dust concentrations with the fungal concentration, CO₂ and relative humidity. A negative correlation was found between concentrations of each microbe group and the airflow velocity. Swine farm workers are exposed to relatively low dust concentrations and high concentrations of microorganisms, bacteria in particular. Fungi, to a much larger extent than bacteria, are correlated with the respirable particles of a piggery bioaerosol, which may harm the respiratory system of exposed workers.     

Inhibition of protein translocation at the endoplasmic reticulum promotes activation of the unfolded protein response

Selective small-molecule inhibitors represent powerful tools for the dissection of complex biological processes. ES(I) (eeyarestatin I) is a novel modulator of ER (endoplasmic reticulum) function. In the present study, we show that in addition to acutely inhibiting ERAD (ER-associated degradation), ES(I) causes production of mislocalized polypeptides that are ubiquitinated and degraded. Unexpectedly, our results suggest that these non-translocated polypeptides promote activation of the UPR (unfolded protein response), and indeed we can recapitulate UPR activation with an alternative and quite distinct inhibitor of ER translocation. These results suggest that the accumulation of non-translocated proteins in the cytosol may represent a novel mechanism that contributes to UPR activation.     

Identification of novel telomeric G-quadruplex-targeting chemical scaffolds through screening of three NCI libraries

Thirteen compounds with diverse chemical structures have been identified as selective telomeric G-quadruplex-binding ligands through screening the NCI Diversity Set II, the NCI Natural Products Set II and the NCI Mechanistic Diversity Set libraries containing a total of 2307 members against a human telomeric G-quadruplex using a FRET-based DNA melting assay. These compounds show significant selectivity towards a telomeric G-quadruplex compared to duplex DNA, fall within a molecular weight range of 327-533, and are generally consistent with the Lipinski Rule of Five for drug-likeness. Thus they provide new chemical scaffolds for the development of novel classes of G-quadruplex-targeting agents.     

Swarming generates rebel workers in honeybees

According to kin selection theory, the colony kin structure of eusocial insects motivates workers' altruistic behaviors and therefore their sterility or restricted reproduction [1]. Indeed, theory and cross-species comparison confirm that workers engage in their own reproduction depending on relatedness among colony members [2, 3]. We show that in a honeybee colony, the workers switch from their typical altruistic role to a more selfish one if at their larval stage there are environmental cues of an upcoming decline in intracolony relatedness. This happens inevitably when a colony multiplies by swarming and replaces the mother queen with her daughter, because the mother queen's workers are faced with rearing the sister queen's offspring related to them half as much as between sisters. Workers developing from the mother queen's eggs immediately after swarming, in a temporarily queenless colony, had more ovarioles in their ovaries and less-developed hypopharyngeal glands producing brood food than control workers reared in queenright conditions. These "rebel" workers were more engaged in laying their own male-determined eggs than in rearing offspring, whether or not the sister queen was present in the colony. The finding of this previously unknown rebel strategy confirms that kin selection shapes both cooperation and conflict in honeybee societies.     

Impact of IL28B-related single nucleotide polymorphisms on liver histopathology in chronic hepatitis C genotype 2 and 3

Background and Aims

Recently, several genome-wide association studies have revealed that single nucleotide polymorphisms (SNPs) in proximity to IL28B predict spontaneous clearance of HCV infection as well as outcome following peginterferon and ribavirin therapy among HCV genotype 1 infected patients. The present study aimed to evaluate the impact of IL28B SNP variability on liver histology in the context of a phase III treatment trial (NORDynamIC) for treatment-naïve patients with chronic HCV genotype 2 or 3 infection, where pretreatment liver biopsies were mandatory.

Methods

Three hundred and thirty-nine Caucasian patients had samples available for IL28B genotyping (rs12979860) of whom 314 had pretreatment liver biopsies that were evaluated using the Ishak protocol, allowing for detailed grading and staging of liver histopathology.

Results

IL28B CC_rs12979860 genotype in HCV genotype 3 infected patients was associated with higher ALT levels (p<0.0001), higher AST to platelet ratio index (APRI; p = 0.001), and higher baseline viral load (p<0.0001) as compared to patients with the CT or TT genotypes. Additionally the CC_rs12979860 genotype entailed more pronounced portal inflammation (p = 0.02) and steatosis (p = 0.03). None of these associations were noted among HCV genotype 2 infected patients.

Conclusion

This study shows that the CC_rs12979860 SNP is associated with more pronounced liver histopathology in patients chronically infected with HCV genotype 3, which may be secondary to higher viral load. The finding that IL28B variability did not impact on liver pathology or viral load among genotype 2 infected patients implies that IL28B may differentially regulate the course of genotype 2 and 3 infection.     

Effects of chronic caloric restriction on kidney and heart redox status and antioxidant enzyme activities in Wistar rats

Caloric restriction (CR) has been associated with health benefits and these effects have been attributed, in part, to modulation of oxidative status by CR; however, data are still controversial. Here, we investigate the effects of seventeen weeks of chronic CR on parameters of oxidative damage/modification of proteins and on antioxidant enzyme activities in cardiac and kidney tissues. Our results demonstrate that CR induced an increase in protein carbonylation in the heart without changing the content of sulfhydryl groups or the activities of superoxide dismutase and catalase (CAT). Moreover, CR caused an increase in CAT activity in kidney, without changing other parameters. Protein carbonylation has been associated with oxidative damage and functional impairment; however, we cannot exclude the possibility that, under our conditions, this alteration indicates a different functional meaning in the heart tissue. In addition, we reinforce the idea that CR can increase CAT activity in the kidney. [BMB Reports 2012; 45(11): 671-676]     

Lineage-specific fragmentation and nuclear relocation of the mitochondrial cox2 gene in chlorophycean green algae (Chlorophyta)

In most eukaryotes the subunit 2 of cytochrome c oxidase (COX2) is encoded in intact mitochondrial genes. Some green algae, however, exhibit split cox2 genes (cox2a and cox2b) encoding two polypeptides (COX2A and COX2B) that form a heterodimeric COX2 subunit. Here, we analyzed the distribution of intact and split cox2 gene sequences in 39 phylogenetically diverse green algae in phylum Chlorophyta obtained from databases (28 sequences from 22 taxa) and from new cox2 data generated in this work (23 sequences from 18 taxa). Our results support previous observations based on a smaller number of taxa, indicating that algae in classes Prasinophyceae, Ulvophyceae, and Trebouxiophyceae contain orthodox, intact mitochondrial cox2 genes. In contrast, all of the algae in Chlorophyceae that we examined exhibited split cox2 genes, and could be separated into two groups: one that has a mitochondrion-localized cox2a gene and a nucleus-localized cox2b gene ("Scenedesmus-like"), and another that has both cox2a and cox2b genes in the nucleus ("Chlamydomonas-like"). The location of the split cox2a and cox2b genes was inferred using five different criteria: differences in amino acid sequences, codon usage (mitochondrial vs. nuclear), codon preference (third position frequencies), presence of nucleotide sequences encoding mitochondrial targeting sequences and presence of spliceosomal introns. Distinct green algae could be grouped according to the form of cox2 gene they contain: intact or fragmented, mitochondrion- or nucleus-localized, and intron-containing or intron-less. We present a model describing the events that led to mitochondrial cox2 gene fragmentation and the independent and sequential migration of cox2a and cox2b genes to the nucleus in chlorophycean green algae. We also suggest that the distribution of the different forms of the cox2 gene provides important insights into the phylogenetic relationships among major groups of Chlorophyceae.