The Biology of Gregarina fernandoi n. sp. in the Cockroach Pysnoscelus surinamensis with Observations on its Development and Cytochemical Nature

SYNOPSIS. Gregarina fernandoi n. sp. is a eugregarine. Its structure, development and life history in the gut of the cockroach Pycnoscelus surinamensis are described. It is named as a new species on the basis of its size, nuclear structure, structure and form of the gametocyst and oocyst. Observations were made on the different stages of the parasite and related to the pH of the gut. In the ceca, pH 4.5–5, the parasite was in its early stages of development, in the midgut, pH 6.5–7, it was in syzygy and in the rectum, pH 7.5–8, gametocysts were found.     

High copy number of highly similar mariner-like transposons in planarian (Platyhelminthe): evidence for a trans-phyla horizontal transfer

Several DNA sequences similar to the mariner element were isolated and characterized in the platyhelminthe Dugesia (Girardia) tigrina. They were 1,288 bp long, flanked by two 32 bp-inverted repeats, and contained a single 339 amino acid open-reading frame (ORF) encoding the transposase. The number of copies of this element is approximately 8,000 per haploid genome, constituting a member of the middle- repetitive DNA of Dugesia tigrina. Sequence analysis of several elements showed a high percentage of conservation between the different copies. Most of them presented an intact ORF and the standard signals of actively expressed genes, which suggests that some of them are or have recently been functional transposons. The high degree of similarity shared with other mariner elements from some arthropods, together with the fact that this element is undetectable in other planarian species, strongly suggests a case of horizontal transfer between these two distant phyla.      

Transient receptor potential genes, smoking, occupational exposures and cough in adults

Background

Transient receptor potential (TRP) vanilloid and ankyrin cation channels are activated by various noxious chemicals and may play an important role in the pathogenesis of cough. The aim was to study the influence of single nucleotide polymorphisms (SNPs) in TRP genes and irritant exposures on cough.

Methods

Nocturnal, usual, and chronic cough, smoking, and job history were obtained by questionnaire in 844 asthmatic and 2046 non-asthmatic adults from the Epidemiological study on the Genetics and Environment of Asthma (EGEA) and the European Community Respiratory Health Survey (ECRHS). Occupational exposures to vapors, gases, dusts, and/or fumes were assessed by a job-exposure matrix. Fifty-eight tagging SNPs in TRPV1, TRPV4, and TRPA1 were tested under an additive model.

Results

Statistically significant associations of 6 TRPV1 SNPs with cough symptoms were found in non-asthmatics after correction for multiple comparisons. Results were consistent across the eight countries examined. Haplotype-based association analysis confirmed the single SNP analyses for nocturnal cough (7-SNP haplotype: p-global = 4.8 × 10^-6) and usual cough (9-SNP haplotype: p-global = 4.5 × 10^-6). Cough symptoms were associated with exposure to irritants such as cigarette smoke and occupational exposures (p < 0.05). Four polymorphisms in TRPV1 further increased the risk of cough symptoms from irritant exposures in asthmatics and non-asthmatics (interaction p < 0.05).

Conclusions

TRPV1 SNPs were associated with cough among subjects without asthma from two independent studies in eight European countries. TRPV1 SNPs may enhance susceptibility to cough in current smokers and in subjects with a history of workplace exposures.     

Azithromycin and cough-specific health status in patients with chronic obstructive pulmonary disease and chronic cough: a randomised controlled trial

Background

Macrolides reduce exacerbations in patients with COPD. Their effects on health status has not been assessed as primary outcome and is less clear. This study assessed the effects of prophylactic azithromycin on cough-specific health status in COPD-patients with chronic productive cough.

Methods

In this randomised controlled trial 84 patients met the eligibility criteria: age of ≥40 years, COPD GOLD stage ≥2 and chronic productive cough. The intervention-group (n = 42) received azithromycin 250 mg 3 times a week and the control-group (n = 42) received a placebo. Primary outcome was cough-specific health status at 12 weeks, measured with the Leicester Cough Questionnaire (LCQ). Secondary outcomes included generic and COPD-specific health status and exacerbations. Changes in adverse events and microbiology were monitored.

Results

Mean age of participants was 68 ± 10 years and mean FEV1 was 1.36 ± 0.47 L. The improvement in LCQ total score at 12 weeks was significantly greater with azithromycin (difference 1.3 ± 0.5, 95% CI 0.3;2.3, p = 0.01) and met the minimal clinically important difference. Similar results were found for the domain scores, and COPD-specific and generic health status questionnaires. Other secondary endpoints were non-significant. No imbalances in adverse events were found.

Conclusions

Prophylactic azithromycin improved cough-specific health status in COPD-patients with chronic productive cough to a clinically relevant degree.

Trial registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT01071161","term_id":"NCT01071161"}}NCT01071161     

Short- and long-term effects of silver nanoparticles on human microvascular endothelial cells

AIM: To study the response to silver nanoparticles (Ag NP) of human microvascular endothelial cells, protagonists of angiogenesis.METHODS: We cultured human microvascular endothelial cells and endothelial colony-forming cells in their corresponding growth medium. Stock solutions of Ag NP were prepared in culture medium and sonicated before use. They were added at different concentrations and for different times to culture media. The toxicity of Ag NP was investigated by measuring the reduction of yellow tetrazolium salt to dark purple formazan (MTT assay) at 575 nm. After staining with trypan blue, cell proliferation was assessed by counting viable cells. The lactate dehydrogenase leakage assay was performed on culture media by following the oxidation of NADH to NAD+ and monitoring the reaction kinetically at 340 nm. Reactive oxygen species production was quantified using 2’-7’-dichlorofluorescein diacetate. The alkaline comet assay was performed after mixing the cells with low melting-point agarose. Electrophoresis was then conducted and the samples were stained with ethidium bromide and analyzed with a fluorescence microscope.RESULTS: Ag NP are cytotoxic in a dose and time dependent fashion for HMEC. At high concentrations, Ag NP determine loss of membrane integrity as demonstrated by the increased activity of lactate dehydrogenase in the culture medium. Ag NP rapidly stimulate the formation of free radicals. However, pre-incubation with Trolox, apocynin, or N-acetyl-L-cysteine, antioxidants which have different structure and act through different mechanisms, is not sufficient to prevent cytotoxicity. Ag NP also induce DNA damage dose-dependently, as shown by comet assay. When exposed to sublethal concentrations of Ag NP for long times, the cells remain viable but are growth retarded. Interestingly, removal of Ag NP partially rescues cell growth. Also genotoxicity is reversible upon removal of Ag NP from culture medium, suggesting that no permanent modifications occur. It is noteworthy that Ag NP are cytotoxic and genotoxic also for endothelial progenitors, in particular for endothelial colony-forming cells, which participate to angiogenesis.CONCLUSION: Silver nanoparticles are cytotoxic and genotoxic for human microvascular endothelial cells and might become a useful tool to control excessive angiogenesis.