Immunohistochemical and molecular analysis of PI3K/AKT/mTOR pathway in esophageal carcinoma

Among the numerous signaling pathways involved in tumorigenesis, PI3K‐AKT‐mTOR is a key one that regulates diverse cellular functions. However, its prognostic value in esophageal carcinoma remains unclear. In our study, we examined the immunohistochemical expression of phosphorylated (p‐) AKT, mTOR, p70S6K and 4E‐BP1 along with the mutational status of PIK3CA and AKT1 genes by High Resolution Melting Analysis and Pyrosequencing in 44 esophageal carcinomas. The results were correlated with the clinicopathological characteristics of the patients in an effort to define their possible prognostic significance. Total p‐mTOR cytoplasmic expression, assessed in 10 random areas, was positively correlated with tumor stage (Kruskal–Wallis ANOVA, I/II vs III/IV, p = 0.0500). Μoreover, maximum p‐mTOR cytoplasmic immunoexpression, estimated in hot spot areas, was positively associated with tumor grade (Mann–Whitney U test, I/II vs III, p = 0.0565). Interestingly, p‐4E‐BP1 immunoreactivity was negatively correlated with tumor histological grade (Mann–Whitney U test, I/II vs III, p = 0.0427). No mutation was observed in exons 9 and 20 of PIK3CA gene and in exon 4 of AKT1 gene. In conclusion, our findings depict the presence of activated PI3K/AKT/mTOR pathway in esophageal cancer bringing forward p‐mTOR and p‐4E‐BP1 for their potential role in esophageal carcinogenesis. Additional studies are warranted to validate our findings.     

A not-so-basic case of metabolic alkalosis: an analysis featuring Leendert Paul and emphasizing Occam’s razor

A patient had the onset of a severe degree of metabolic alkalosis associated with a very large daily loss of diarrheal fluid. Because the expected acid-base disorder in this setting is metabolic acidosis, factors that could result in the markedly increased concentration of bicarbonate (HCO₃⁻) in plasma (P ₃) were sought. In our approach, there is an emphasis on electroneutrality, mass balance, a quantitative analysis, and the application of basic concepts in physiology at the bedside. We suggest that there were 3 major factors that could explain why the P ₃ was so high. First, a severe degree of extracellular fluid volume contraction was probably the most important factor that raised her P ₃. Second, there may have been an unusual way to have an electroneutral addition of HCO₃⁻ and removal of chloride ions from her extracellular fluid compartment. Third, the diarrheal fluid could have contained little HCO₃⁻ because of a down-regulated intestinal secretion of HCO₃⁻. This analysis challenges the traditional pathophysiology of metabolic alkalosis.     

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A DPSIR Approach to Selected Cr(VI) Impacted Groundwater Bodies of Central Greece

Bulletin of Environmental Contamination and Toxicology - The holistic approach of Driver-Pressure-State-Impact-Response (DPSIR) methodology was applied to selected Cr(VI) impacted groundwater...     

Native valve right sided infective endocarditis

Right-sided infective endocarditis (RSIE) accounts for 5–10% of all cases of infective endocarditis (IE), and is predominantly encountered in the injecting drug user (IDU) population, where HIV and HCV coinfections often coexist. Staphylococcus aureus is the most common pathogen. The pathogenesis of RSIE is still not well understood. RSIE usually presents as a persistent fever with respiratory symptoms whilst signs of systemic embolisation as seen in left-sided IE are notably absent. The prompt diagnosis of RSIE thus requires a high index of suspicion. Transthoracic echocardiography (TTE) can detect the majority of RSIE, whilst transoesophageal echocardiography (TOE) can increase sensitivity. Virulence of the causative organism and vegetation size are the major determinants of prognosis. Most cases of RSIE resolve with appropriate antibiotic administration.     

Prevalence of hemochromatosis gene (HFE) mutations in Greece

The frequencies of the hereditary hemochromatosis gene (HFE) mutations C282Y and H63D vary between different populations. There are a limited number of reports regarding the frequency of these mutations in populations of southeastern Europe. Two hundred and sixty-four adult individuals of Greek origin were examined for the C282Y and H63D mutations to determine the allele and genotype frequencies. The HFE gene region of DNA samples extracted from peripheral leukocytes was amplified by the polymerase chain reaction. Restriction enzyme analysis was performed using RSAI for C282Y and MBOI for H63D. None of the 264 individuals carried the mutation C282Y. Forty-three individuals (16.2%) were heterozygous carriers of the H63D allele and 2 were homozygous for this mutation (0.75%). The overall H63D allele prevalence is thus estimated at 8.9%. HFE mutation frequencies were low in the population studied and this may explain, in part, the relative rarity of clinical cases of hereditary hemochromatosis in Greece.