Species Differences in Developmental Toxicity of Epoxiconazole and Its Relevance to Humans

Epoxiconazole, a triazole‐based fungicide, was tested in toxicokinetic, prenatal and pre‐postnatal toxicity studies in guinea pigs, following oral (gavage) administration at several dose levels (high dose: 90 mg/kg body weight per day). Maternal toxicity was evidenced by slightly increased abortion rates and by histopathological changes in adrenal glands, suggesting maternal stress. No compound‐related increase in the incidence of malformations or variations was observed in the prenatal study. In the pre‐postnatal study, epoxiconazole did not adversely affect gestation length, parturition, or postnatal growth and development. Administration of epoxiconazole did not alter circulating estradiol levels. Histopathological examination of the placentas did not reveal compound‐related effects. The results in guinea pigs are strikingly different to those observed in pregnant rats, in which maternal estrogen depletion, pathological alteration of placentas, increased gestation length, late fetal death, and dystocia were observed after administration of epoxiconazole. In the studies reported here, analysis of maternal plasma concentrations and metabolism after administration of radiolabeled epoxiconazole demonstrated that the different results in rats and guinea pigs were not due to different exposures of the animals. A comprehensive comparison of hormonal regulation of pregnancy and birth in murid rodents and primates indicates that the effects on pregnancy and parturition observed in rats are not applicable to humans. In contrast, the pregnant guinea pig shares many similarities to pregnant humans regarding hormonal regulation and is therefore considered to be a suitable species for extrapolation of related effects to humans. Birth Defects Res (Part B) 98:230–246, 2013. © 2013 Wiley Periodicals, Inc.     

A Re-Emerging Marker for Prognosis in Hepatocellular Carcinoma: The Add-Value of FISHing c-myc Gene for Early Relapse

Hepatocellular carcinoma is one leading cause of cancer-related death and surgical resection is still one of the major curative therapies. Recently, there has been a major effort to find mechanisms involved in carcinogenesis and early relapse. c-myc gene abnormality is found in hepatocarcinogenesis. Our aim was to analyze the role of c-myc as prognostic factor in terms of overall survival and disease-free survival and to investigate if c-myc may be an important target for therapy. We studied sixty-five hepatocellular carcinomas submitted to surgical resection with curative intent. Size, macro-microvascular invasion, necrosis, number of nodules, grading and serum alfa-fetoprotein level were registered for all cases. We evaluated the c-myc aberrations by using break-apart FISH probes. Probes specific for the centromeric part of chromosome 8 and for the locus specific c-myc gene (8q24) were used to assess disomy, gains of chromosomes (polysomy due to polyploidy) and amplification. c-myc gene amplification was scored as 8q24/CEP8 > 2. Statistical analysis for disease-free survival and overall survival were performed. At molecular level, c-myc was amplified in 19% of hepatocellular carcinoma, whereas showed gains in 55% and set wild in 26% of cases. The 1- and 3-year disease-free survival and overall survival for disomic, polysomic and amplified groups were significantly different (p=0.020 and p=.018 respectively). Multivariate analysis verified that the AFP and c-myc status (amplified vs. not amplified) were significant prognostic factors for overall patients survival. c-myc gene amplification is significantly correlated with disease-free survival and overall survival in patients with hepatocellular carcinoma after surgical resection and this model identifies patients with risk of early relapse (≤12 months). We suggest that c-myc assessment may be introduced in the clinical practice for improving prognostication (high and low risk of relapse) routinely and may have be proposed as biomarker of efficacy to anti-c-myc targeted drugs in clinical trials.     

Impact of Cardiovascular Calcifications on the Detrimental Effect of Continued Smoking on Cardiovascular Risk in Male Lung Cancer Screening Participants

Background

Current smokers have an increased cardiovascular disease (CVD) risk compared to ex-smokers due to reversible as well as irreversible effects of smoking. We investigated if current smokers remain to have an increased CVD risk compared to ex-smokers in subjects with a long and intense smoking history. We in addition studied if the effect of smoking continuation on CVD risk is independent of or modified by the presence of cardiovascular calcifications.

Methods

The cohort used comprised a sample of 3559 male lung cancer screening trial participants. We conducted a case-cohort study using all CVD cases and a random sample of 10% (n = 341) from the baseline cohort (subcohort). A weighted Cox proportional hazards model was used to estimate the hazard ratios for current smoking status in relation to CVD events.

Results

During a median follow-up of 2.6 years (max. 3.7 years), 263 fatal and non-fatal cardiovascular events (cases) were identified. Age, packyears and cardiovascular calcification adjusted hazard ratio of current smokers compared to former smokers was 1.33 (95% confidence interval 1.00–1.77). In additional analyses that incorporated multiplicative interaction terms, neither coronary nor aortic calcifications modified the association between smoking status and cardiovascular risk (P = 0.08).

Conclusions

Current smokers have an increased CVD risk compared to former smokers even in subjects with a long and intense smoking history. Smoking exerts its hazardous effects on CVD risk by pathways partly independent of cardiovascular calcifications.     

Methodological Rigour and Transparency of Clinical Practice Guidelines Developed by Neurology Professional Societies in Croatia

Background

Clinical practice guidelines are systematically created documents that summarize knowledge and assist in delivering high-quality medicine by identifying evidence that supports best clinical care. They are produced not only by international professional groups but also by local professionals to address locally-relevant clinical practice. We evaluated the methodological rigour and transparency of guideline development in neurology formulated by professionals in a local medical community.

Methods

We analyzed clinical guidelines in neurology publicly available at the web-site of the Physicians’ Assembly in Croatia in 2012: 6 guidelines developed by Croatian authors and 1 adapted from the European Federation of Neurological Societies. The quality was assessed by 2 independent evaluators using the AGREE II instrument. We also conducted a search of the Cochrane Library to identify potential changes in recommendation from Cochrane systematic reviews included in guideline preparation.

Results

The methodological quality of the guidelines greatly varied across different domains. „Scope and Purpose” and „Clarity of Presentation“ domains received high scores (100% [95% confidence interval (CI) 98.5–100] and 97% [77.9–100], respectively), the lowest scores were in “Stakeholder Involvement“ (19% [15.5–34.6]) and “Editorial Independence” (0% [0–19.2]). Conclusions of 3 guidelines based on Cochrane systematic reviews were confirmed in updated versions and one update provided new information on the effectiveness of another antidepressant. Two Cochrane reviews used in guidelines were withdrawn and split into new reviews and their findings are now considered to be out of date.

Conclusion

Neurological guidelines used in Croatia differ in structure and their methodological quality. We recommend to national societies and professional groups to develop a more systematic and rigorous approach to the development of the guidelines, timely inclusion of best evidences and an effort to involve target users and patients in the guideline development procedures.     

Element content and expression of genes of interest in guard cells are connected to spatiotemporal variations in stomatal conductance

Element content and expression of genes of interest on single cell types, such as stomata, provide valuable insights into their specific physiology, improving our understanding of leaf gas exchange regulation. We investigated how far differences in stomatal conductance (g_s) can be ascribed to changes in guard cells functioning in amphistomateous leaves. g_s was measured during the day on both leaf sides, on well-watered and drought-stressed trees (two Populus euramericana Moench and two Populus nigra L. genotypes). In parallel, guard cells were dissected for element content and gene expressions analyses. Both were strongly arranged according to genotype, and drought had the lowest impact overall. Normalizing the data by genotype highlighted a structure on the basis of leaf sides and time of day both for element content and gene expression. Guard cells magnesium, phosphorus, and chlorine were the most abundant on the abaxial side in the morning, where g_s was at the highest. In contrast, genes encoding H⁺-ATPase and aquaporins were usually more abundant in the afternoon, whereas genes encoding Ca²⁺-vacuolar antiporters, K⁺ channels, and ABA-related genes were in general more abundant on the adaxial side. Our work highlights the unique physiology of each leaf side and their analogous rhythmicity through the day.     

Biochemical characterization of ClpB3, a chloroplastic disaggregase from Arabidopsis thaliana

Plant Molecular Biology - The first biochemical characterization of a chloroplastic disaggregase is reported (Arabidopsis thaliana ClpB3). ClpB3 oligomerizes into active hexamers that resolubilize...     

Bacterial and algal symbiont dynamics in early recruits exposed to two adult coral species

Coral Reefs - Corals live in a symbiotic relationship with various microorganisms including bacteria, some of which are essential for host health and survival. Bacterial assemblages are typically...     

Interaction of piroxicam with bovine serum albumin investigated by spectroscopic,calorimetric and computational molecular methods

Abstract

The binding of drugs to serum proteins is governed by weak non-covalent forces. In this study, the nature and magnitude of the interactions between piroxicam (PRX) and bovine serum albumin (BSA) was assessed using spectroscopic, calorimetric and computational molecular methods. The fluorescence data revealed an atypical behavior during PRX and BSA interaction. The quenching process of tryptophan (Trp) by PRX is a dual one (approximately equal static and dynamic quenched components). The FRET results indicate that a non-radiative transfer of energy occurred. The association constant and the number of binding sites indicate moderate PRX and BSA binding. The competitive binding study indicates that PRX is bound to site I from the hydrophobic pocket of subdomain IIA of BSA. The synchronous spectra showed that the microenvironment around the BSA fluorophores and protein conformation do not change considerably. The Trp lifetimes revealed that PRX mainly quenches the fluorescence of Trp-213 situated in the hydrophobic domain. The CD and DSC investigation show that addition of PRX stabilizes the protein structure. ITC results revealed that BSA-PRX binding involves a combination of electrostatic, hydrophobic and hydrogen interactions. The analysis of the computational data is consistent with the experimental results. This thorough investigation of the PRX-BSA binding may provide support for other studies concerning moderate affinity drugs with serum protein.

Communicated by Ramaswamy H. Sarma