Curiosity or aggressivity? Surface predatory behavior of the great white shark

The Great White Shark (Carcharodon carcharias) is an important top predator; however a little is known about its behaviour. During five study expeditions surface behaviour of Great White Sharks living in Dyer Island (South Africa) was observed. Aims of the research were to give more data in order to confirm the hypothesis that this area could be considered as a “training place”, where young sharks can learn new predator techniques, and to understand what is shark approach to a unnatural, floating and passive prey. By comparing behaviours performed by young and mature specimens, our data showed that latters exhibited more complex ethograms. Sharks showed also a curiosity approach to passive preys employed for this studies, with a strong predominance of the parading

Tissue kallikrein is essential for invasive capacity of circulating proangiogenic cells

RATIONALE: Homing of proangiogenic cells (PACs) is guided by chemoattractants and requires proteases to disrupt the extracellular matrix. The possibility that PAC recruitment involves an interaction between proteases and chemotactic factor receptors remains largely unexplored. OBJECTIVE: To determine the role of human tissue kallikrein (hK1) in PAC invasion and its dependency on kinin receptor signaling. METHODS AND RESULTS: Human mononuclear cells (MNCs) and culture-selected PACs express and release mature hK1 protein. HK1 gene (KLK1) silencing reduced PACs migratory, invasive, and proangiogenic activities. KLK1-knockout mouse bone marrow–derived MNCs showed similar impairments and were unable to support reparative angiogenesis in a mouse model of peripheral ischemia. Conversely, adenovirus-mediated KLK1 (Ad.KLK1) gene transfer enhanced PAC-associated functions, whereas the catalytically inactive variant R53H-KLK1 was ineffective. HK1-induced effects are mediated by a kinin B(2) receptor (B(2)R)-dependent mechanism involving inducible nitric oxide synthase and metalloproteinase-2 (MMP2). Lower hK1 protein levels were observed in PACs from type 2 diabetic (T2D) patients, whereas KLK1 mRNA levels were similar to those of healthy subjects, suggesting a post-transcriptional defect. Furthermore, B(2)R is normally expressed on T2D-PACs but remains uncoupled from downstream signaling. Importantly, whereas Ad.KLK1 alone could not restore T2D-PAC invasion capacity, combined KLK1 and B(2)R expression rescued the diabetic phenotype. CONCLUSIONS: This study reveals new interactive components of the PACs invasive machinery, acting via protease- and kinin receptor–dependent mechanisms

Ombitasvir/Paritaprevir/Ritonavir and Dasabuvir Combination Treatment in Patients with HIV/HCV Co-Infection: Results of an Italian Compassionate Use Program

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Trend of estimated glomerular filtration rate during ombistasvir/paritaprevir/ritonavir plus dasabuvir ± ribavirin in HIV/HCV co-infected patients.

The renal function is a key-issue in HIV/HCV co-infected patients, nevertheless, it has not established so far whether HCV treatment with new direct acting agents could impact on estimated glomerular filtration rate (eGFR) variations. In the present work, we examined the real-life data on renal function that have been prospectively collected in the SIMIT compassionate-use program of ombitasvir/paritaprevir/ritonavir plus dasabuvir (OBV/PTV/r + DSV) in 144 HIV/HCV genotype 1 co-infected patients. The population was 74% male, 30.5% in CDC stage C, with median age of 52 years (48.0-56.5) and median liver stiffness of 7.8 kPa (6.7-9.2). Median baseline eGFR was 102.0 (90.8-108.1), changing to 99.8 (83.5-104.8) at the end of treatment (EoT), and 100.0 (87.3-105.6) 12 weeks after the EoT (FU12), p<0.0001. No patient had grade 3-4 increase of creatinine. At EoT 60/144 (41.7%) patients had ≥ 5% reduction in their eGFR, confirmed at FU12 in 39/60 (65.0%) cases. Longer duration of HCV infection (cut-off 12.9 years), lower HCV-RNA viral load (cut-off 1,970,160 IU/ml) and lower platelet count (cut-off 167,000 x106/L) were significantly associated with eGFR decline at logistic analysis (adjOR 2.9, 95%CI 1.0-8.8, p = 0.05; adjOR 3.5, 95%CI 1.2-10.4, p = 0.02; adjOR 2.8, 95%CI 1.1-6.8, p = 0.03, respectively). After repeating the analysis throughout a mixed model, a higher eGFR decline was highlighted in patients concomitantly treated with tenofovir (p = 0.0001), ribavirin (p = 0.0001), or integrase inhibitors (p <0.0001), with longer duration of HIV (p = 0.0002) and HCV infection (p = 0.035), lower baseline HCV RNA (p <0.0001), previous HCV treatment (p<0.0001), and older age (p<0.0001). In conclusion, our study confirms a good renal safety profile of OBV/PTV/r + DSV treatment in HIV/HCV patients, and the median decline of 2 ml/min in eGFR, albeit statistically significant, is of doubtful clinical significance. The role of aging, concomitant therapies and duration of HIV/HCV infection needs to be further investigated

The COVID-19 puzzle: deciphering pathophysiology and phenotypes of a new disease entity

The zoonotic SARS-CoV-2 virus that causes COVID-19 continues to spread worldwide, with devastating consequences. While the medical community has gained insight into the epidemiology of COVID-19, important questions remain about the clinical complexities and underlying mechanisms of disease phenotypes. Severe COVID-19 most commonly involves respiratory manifestations, although other systems are also affected, and acute disease is often followed by protracted complications. Such complex manifestations suggest that SARS-CoV-2 dysregulates the host response, triggering wide-ranging immuno-inflammatory, thrombotic, and parenchymal derangements. We review the intricacies of COVID-19 pathophysiology, its various phenotypes, and the anti-SARS-CoV-2 host response at the humoral and cellular levels. Some similarities exist between COVID-19 and respiratory failure of other origins, but evidence for many distinctive mechanistic features indicates that COVID-19 constitutes a new disease entity, with emerging data suggesting involvement of an endotheliopathy-centred pathophysiology. Further research, combining basic and clinical studies, is needed to advance understanding of pathophysiological mechanisms and to characterise immuno-inflammatory derangements across the range of phenotypes to enable optimum care for patients with COVID-19

The COVID-19 puzzle:deciphering pathophysiology and phenotypes of a new disease entity

The zoonotic SARS-CoV-2 virus that causes COVID-19 continues to spread worldwide, with devastating consequences. While the medical community has gained insight into the epidemiology of COVID-19, important questions remain about the clinical complexities and underlying mechanisms of disease phenotypes. Severe COVID-19 most commonly involves respiratory manifestations, although other systems are also affected, and acute disease is often followed by protracted complications. Such complex manifestations suggest that SARS-CoV-2 dysregulates the host response, triggering wide-ranging immuno-inflammatory, thrombotic, and parenchymal derangements. We review the intricacies of COVID-19 pathophysiology, its various phenotypes, and the anti-SARS-CoV-2 host response at the humoral and cellular levels. Some similarities exist between COVID-19 and respiratory failure of other origins, but evidence for many distinctive mechanistic features indicates that COVID-19 constitutes a new disease entity, with emerging data suggesting involvement of an endotheliopathy-centred pathophysiology. Further research, combining basic and clinical studies, is needed to advance understanding of pathophysiological mechanisms and to characterise immuno-inflammatory derangements across the range of phenotypes to enable optimum care for patients with COVID-19

Number of patients tested throughout mixed models and correlation with eGFR decline at different time-points.

<p>Number of patients tested throughout mixed models and correlation with eGFR decline at different time-points.</p

Trend of estimated glomerular filtration rate (eGFR) in the global population, according to GITMO renal stage at baseline (BL).

<p>n = number of patients in each chronic kidney disease (CKD) stage. EoT: End of treatment; FU12: follow-up 12 weeks after the EoT; FU24: follow-up 24 weeks after the EoT.</p

Univariate and multivariate predictors of event (eGFR decline > 5%) in the study population (144 patients).

<p>Univariate and multivariate predictors of event (eGFR decline > 5%) in the study population (144 patients).</p