Prophylaxis of venous thromboembolism

The recommendations on venous thromboprophylaxis have been updated on the basis of current evidence reviewed by a multidisciplinary team. The problem has been approached with regard to its relevance in both surgical and nonsurgical patients. It should be noted that these recommendations were drawn up for use in Spain and, therefore, should be implemented with the drugs and therapeutic practices authorized and generally accepted in this country.     

Hepatitis A virus cellular receptor 1/kidney injury molecule-1 is a susceptibility gene for clear cell renal cell carcinoma and hepatitis A virus cellular receptor/kidney injury molecule-1 ectodomain shedding a predictive biomarker of tumour progression

Aim of the studyTo correlate hepatitis A virus cellular receptor (HAVCR)/kidney injury molecule-1 (KIM-1) expression in clear cell renal cell carcinoma (ccRCC) tumours with patient outcome and study the consequences of HAVCR/KIM-1 ectodomain shedding.MethodsHAVCR/KIM-1 expression in ccRCC, oncocytomes, papillary carcinomas and unaffected tissue counterparts was evaluated. Minimal change disease and pre-clamping normal and ccRCC tissue biopsies were included. Tissue microarrays from 98 ccRCC tumours were analysed. Tumour registry data and patient outcome were retrospectivelly collected. Deletions in HAVCR/KIM-1 ectodomain and lentiviral infection of 786-O cells with HAVCR/KIM-1 mutated constructs to determine their subcellular distribution and invasive capacity were performed.ResultsHAVCR/KIM-1 was expressed in ccRCC, papillary tumours and in tubule cells of adjacent and distal unaffected counterparts of ccRCC tumours. The latest was not related to ischemic or tumour-related paracrine effects since pre-clamping normal biopsies were positive for HAVCR/KIM-1 and unaffected counterparts of papillary tumours were negative. HAVCR/KIM-1 analyses in patients and the invasive capacity of HAVCR/KIM-1 shedding mutants in cell lines demonstrated that: (i) relative low HAVCR/KIM-1 membrane levels correlate with activated shedding in ccRCC patients and mutant cell lines; (ii) augmented shedding directly correlates with higher invasiveness and tumour malignancy.Concluding statementsConstitutive expression of HAVCR/KIM-1 in kidney might constitute a susceptibility trait for ccRCC tumour development. Enhanced HAVCR/KIM-1 ectodomain shedding promotes invasive phenotype in vitro and more aggressive tumours in vivo.     

BRAF mutations characterize colon but not gastric cancer with mismatch repair deficiency

Genes from the RAF family are Ras-regulated kinases involved in growth cellular responses. Recently, a V599E hotspot mutation within the BRAF gene was reported in a high percentage of colorectal tumors and significantly associated to defective mismatch repair (MMR). Additionally, BRAF mutations were described only in K-Ras-negative colon carcinomas, suggesting that BRAF/K-Ras activating mutations might be alternative genetic events in colon cancer. We have addressed to what extent the tumorigenic-positive selection exerted by BRAF mutations seen in colorectal MMR-deficient tumors was also involved in the tumorigenesis of gastric cancer. Accordingly, BRAF mutations were detected in 34% (25/74) of colorectal MMR-deficient tumors and in 5% (7/142) of MMR-proficient colorectal cases (P=0.0001). All mutations found in the MSI cases corresponded to the previously reported hotspot V599E. Two D593K and a K600E additional mutations were also detected in three MSS cases. However, only one mutation of BRAF was found within 124 MSS gastric tumors and none in 37 MSI gastric tumors, clearly suggesting that BRAF mutations are not involved in gastric tumorigenesis. Nonetheless, a high incidence of mutations of K-Ras was found within the MSI gastric group of tumors (P=0.0005), suggesting that the activation of K-Ras-dependent pathways contributes to the tumorigenesis of gastric cancers with MMR deficiency. Accordingly, our results show evidences that BRAF mutations characterize colon but not gastric tumors with MMR deficiency and are not involved in the tumorigenesis of gastric cancer of the mutator phenotype pathway.     

Intake of high levels of vitamin A and polyunsaturated fatty acids during different developmental periods modifies the expression of morphogenesis genes in European sea bass (Dicentrarchus labrax)

The effect of the feeding period on larval development was investigated in European sea bass larvae by considering the expression level of some genes involved in morphogenesis. Larvae were fed a control diet except during three different periods (period A: from 8 to 13 d post-hatching (dph); period B: from 13 to 18 dph; period C: from 18 to 23 dph) with two compound diets containing high levels of vitamin A or PUFA. European sea bass morphogenesis was affected by these two dietary nutrients during the early stages of development. The genes involved in morphogenesis could be modulated between 8 and 13 dph, and our results indicated that retinoids and fatty acids influenced two different molecular pathways that in turn implicated two different gene cascades, resulting in two different kinds of malformation. Hypervitaminosis A delayed development, reducing the number of vertebral segments and disturbing bone formation in the cephalic region. These malformations were correlated to an upregulation of retinoic acid receptor gamma, retinoid X receptor (RXR) alpha and bone morphogenetic protein (BMP)4. An excess of PUFA accelerated the osteoblast differentiation process through the upregulation of RXRalpha and BMP4, leading to a supernumerary vertebra. These results suggest that the composition of diets devoted to marine fish larvae has a particularly determining effect before 13 dph on the subsequent development of larvae and juvenile fish.     

Assessment of right ventricular afterload by pressure waveform analysis in acute pulmonary hypertension

AIM: To characterize hydraulic right ventricle (RV) af- terload by pulmonary arterial pressure waveform analy- sis in an acute pulmonary hypertension (PH) model. METHODS: Pulmonary artery (PA) flow and pressure were recorded in six anesthetized sheep. Acute iso- baric PH was induced by phenylephrine (active) and PA mechanical constriction (passive). We estimated the amplitude of the forward and reflected pressure waves according to the inflection point. In most cases the in- flection pressure was smooth, thus the inflection point was defined as the time at which the first derivative ofpulmonary arterial pressure reached its first minimum. We calculated the input and characteristic (Z C , time- domain Li method) impedances, the capacitance index (stroke volume/pulse pressure), the augmentation index (AI) (reflected pressure/pulse pressure), the frac- tional pulse pressure (pulse pressure/mean pressure) and the wasted energy generated by the RV due to wave reflection during ejection (E W ). RESULTS: Pulse pressure, fractional pulse pressure, AI and Z C increased and capacitance index decreased during passive PH with respect to control (P < 0.05). In contrast, Z C and the capacitance index did not change and E W and the AI decreased during active PH. Pulse pressure correlated with E W and Z C and the AI was cor- related with E W (r > 0.6, P < 0.05). CONCLUSION: PA pressure waveform analysis al- lows the quantification of the dynamic RV afterload. Prospective clinical studies will be necessary to validate this time-domain approach to evaluate the dynamic RV afterload in chronic PH.