On the Wall Shear Stress Gradient in Fluid Dynamics

The gradient of the fluid stresses exerted on curved boundaries, conventionally computed in terms of directional derivatives of a tensor, is here analyzed by using the notion of intrinsic derivative which represents the geometrically appropriate tool for measuring tensor variations projected on curved surfaces. Relevant differences in the two approaches are found by using the classical Stokes analytical solution for the slow motion of a fluid over a fixed sphere and a numerically generated three dimensional dynamical scenario. Implications for theoretical fluid dynamics and for applied sciences are finally discussed.     

Interventional Radiological Treatment of Renal Transplant Complications: A Pictorial Review

Renal transplantation is the treatment of choice for patients with chronic renal failure, which produces a dramatic improvement in the quality of life and survival rates, in comparison to long-term dialysis. Nowadays, new imaging modalities allow early diagnosis of complications, and thanks to the recent developments of interventional techniques, surgery may be avoided in most cases. Knowledge in the types of renal transplant complications is fundamental for a correct pre-operative planning. In this article, we described the most common or clinically relevant renal transplant complications and explained their interventional management.     

Saccharomyces cerevisiae-associated diarrhea in an immunocompetent patient with ulcerative colitis

Infectious diarrhea is common in cases of ulcerative colitis (UC), caused by resistance to treatment. In particular, it has been associated with cytomegalovirus or infection has rarely been observed in human beings, but has never been seen in immunocompetent patients. We report a case of intestinal infection presenting as acute diarrhea in a patient with a 10-year history of UC who was never treated with immunosuppressants.     

基于动态ECG门控CTA的动脉瘤颈近侧血管搏动变化与血管内支架管径选择的研究

目的使用64层ECG门控CTA测量和评估腹主动脉瘤病人血管内修复(EVAR)时的腹主动脉瘤颈(AAA)近侧管径的变化,以评价血管搏动对选择血管内支架管径的影     

Clinical presentation,therapeutic approach,and outcome of young patients admitted for COVID-19, with respect to the elderly counterpart

There is limited information on the presenting characteristics, prognosis, and therapeutic approaches of young patients hospitalized for coronavirus disease 2019 (COVID-19). We sought to investigate the baseline characteristics, in-hospital treatment, and outcomes of a wide cohort < 65 years admitted for COVID-19. Using the international multicenter HOPE-COVID-19 registry, we evaluated the baseline characteristics, clinical presentation, therapeutic approach, and prognosis of patients < 65 years discharged (deceased or alive) after hospital admission for COVID-19, also compared with the elderly counterpart. Of the included 5746 patients, 2676 were < 65 and 3070 ≥ 65 years. All risk factors and several parameters suggestive of worse clinical presentation augmented through increasing age classes. In-hospital mortality rates were 6.8% and 32.1% in the younger and older cohort, respectively (p < 0.001). Among young patients, mortality, access to ICU and treatment with IMVwere positively correlated with age. Contrariwise, over 65 years of age this trend was broken so that only the association between age and mortality was persistent, while the rates of access to ICU and IMV started to decline. Younger patients also recognized specific predictors of case fatality, such as obesity and gender. Age negatively impacts on mortality, access to ICU and treatment with IMV in patients < 65 years. In elderly patients only case fatality rate keeps augmenting in a stepwise manner through increasing age categories, while therapeutic approaches become more conservative. Besides age, obesity, gender, history of cancer, and severe dyspnea, tachypnea, chest X-ray bilateral abnormalities, abnormal level of creatinine and leucocyte among admission parameters seem to play a central role in the outcome of patients younger than 65 years.

     

A human umbilical cord stem cell rescue therapy in a murine model of toxic liver injury

BACKGROUND: Several studies have demonstrated that bone marrow contains a subpopulation of stem cells capable of participating in the hepatic regenerative process, even if some reports indicate quite a low level of liver repopulation by human stem cells in the normal and transiently injured liver. AIMS: In order to overcome the low engraftment levels seen in previous models, we tried the direct intraperitoneal administration of human cord blood stem cells, using a model of hepatic damage induced by allyl alcohol in NOD/SCID mice. METHODS: We designed a protocol based on stem cell infusion following liver damage in the absence of irradiation. Flow cytometry, histology, immunohistochemistry and RT-PCR for human hepatic markers were performed to monitor human cell engraftment. RESULTS: Human stem cells were able to transdifferentiate into hepatocytes, to improve liver regeneration after damage and to reduce the mortality rate both in both protocols, even if with qualitative and quantitative differences in the transdifferentiation process. CONCLUSIONS: We demonstrated for the first time that the intraperitoneal administration of stem cells can guarantee a rapid liver engraftment. Moreover, the new protocol based on stem cell infusion following liver damage in the absence of irradiation may represent a step forward for the clinical application of stem cell transplantation.