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Wall shear stress (WSS) is an important stimulus in vascular remodelling and vascular lesion development. The current methods to assess and predict the risk associated with specific unsteady WSS consider the WSS mean values or the presence of reverse phases described by the oscillatory shear index. Recent evidence has shown that the accuracy of these methods is limited, especially with respect to the venous environment. Unsteady WSS are characterised by several features that may individually affect endothelial cells. Consequently, we assessed the effects of averaged WSS (TAWSS), temporal WSS gradient (TWSSG), maximum WSS (WSS peak) and reverse phase (OSI) by applying different WSS profiles to venous EC in-vitro, using a real-time controlled cone-and-plate cell-shearing device for 24 h. We found that TWSSG and WSS peak affect cell elongation and alignment respectively. We also found that the WSS waveforms with a peak of 1.5 Pa or higher significantly correlate with the induction of a protective phenotype. Cell phenotype induced by these high peak waveforms does not correlate to what is predicted by the hemodynamic indices currently used. The definition of reliable hemodynamic indices can be used to inform the computational models aimed at estimating the hemodynamic effects on vascular remodelling. [ABSTRACT FROM AUTHOR]

Pathologies of the aortic valve such as aortic sclerosis are thought to impact coronary blood flow. Recent clinical investigations have observed simultaneous structural and hemodynamic variations in the aortic valve and coronary arteries due to regional pathologies of the aortic valve. The goal of the present study is to elucidate this observed and yet unexplained phenomenon, in which a local pathology in the aortic valve region could potentially lead to the initiation or progression of coronary artery disease. Results revealed a considerable impact on the coronary flow, velocity profile, and consequently shear stress due to an increase in the aortic wall or aortic leaflet stiffness and thickness which concur with clinical observations. The cutoff value of 0.75 for fractional flow reserve was reached when the values of leaflet thickness and aortic wall stiffness were approximately twice and three times their normal value, respectively. Variations observed in coronary velocity profiles as well as wall shear stress suggest a possible link for the initiation of coronary artery disease. [ABSTRACT FROM AUTHOR]

The atmospheric pressure glow discharge torch (APGD-t) is a miniature pulsed RF (13.56 MHz) plasma source specifically designed to efficiently produce and transport reactive species to and interact with biological samples. When applied to adherent cell cultures, the APGD-t is capable of inducing temporary cell permeabilization. In this work, we evaluate the maximum radius of macromolecules able to enter into HeLa cells following a plasma treatment using a size exclusion approach with dextran molecules. We observe that this maximum radius is below 6.5 nm. We also show that no degradation occurs when a plasmid DNA suspended in culture media is plasma-treated at the operating conditions leading to cell permeabilization. The plasma-assisted DNA transfection of the HeLa cells with the hrGFP-II-1 plasmid using the APGD-t is demonstrated. Local transfection efficiencies obtained are as high as 35%. [ABSTRACT FROM AUTHOR]

Objectives:We studied collagen plugging of the fetoscopic access site in an in vivo fetal lamb model for fetoscopic surgery and possible role for matrix metalloproteinase (MMP)-2 and -9 and tissue inhibitors (TIMPs).Methods:Eight ewes had fetoscopic balloon occlusion of the trachea as an experimental treatment for congenital diaphragmatic hernia between days 88 and 99 of gestation (term 145 days) with sampling of amniotic, allantoic, and tracheal fluid. Nonoperated cotwins were used as controls. The fetoscopy port was closed using a collagen plug. Ten days (range 9-12) later, fluids were sampled and plug sites collected for histologic analysis. Activity of MMP-2 (72 kDa, gelatinase A) and MMP-9 (92 kDa, gelatinase B) was determined in the fluids by zymography and secretion of TIMPs (27-30 kDa; TIMP-1, glycosylated TIMP-3 and TIMP-4, 24 kDa; unglycosylated TIMP-3, 21 kDa; TIMP-2) by reverse zymography and quantified by densitometric analysis.Results:No pregnancy was complicated by amniorhexis or preterm labor. At cesarean, normal volumes of amniotic and allantoic fluid were present in all cases. Histology of the plug sites revealed good integration of the collagen plug without complete restoration of membrane integrity. MMP-2, MMP-9, and TIMps were detected in all fluids. In the operated animals, significantly (P < .05) higher activity of MMP-9 was found in amniotic fluid, with lower concentrations of TIMPs in allantoic fluid (P < .01). Tracheal occlusion was associated with a significant (P < .02) increase in both MMP-2 and -9 in tracheal fluid.Conclusion:Collagen plugging of the fetoscopic access port sites in sheep resulted in functionally effective sealing of the fetal membranes. Changes in MMP-2, MMP-9, and TIMPs suggest an active remodeling of both the fetal lung and the fetal membranes. [ABSTRACT FROM PUBLISHER]

Dietary potassium intake was estimated in 46 men and 88 women randomly selected from people aged 65 and over living in their own homes, and 24-hour urinary potassium, creatinine, and urea excretions were determined. The mean dietary potassium intake was 71 mEq/day in men and 54 mEq/day in women. There was a decline with age in both sexes. The sex and age differences were eliminated by expression of dietary potassium intake per unit lean body mass. Urinary potassium excretion averaged 51 mEq/day in men and 44 mEq/day in women, and again the sex difference and decline with age were abolished by expression of urinary potassium per unit lean body mass. There were highly significant relationships between dietary and urinary potassium. Consideration of the regression lines of these correlations suggested that if faecal potassium losses were 5 mEq/day, a negative potassium balance would be inevitable if dietary potassium fell below 27 mEq/day in men and 35 mEq/day in women. These findings are discussed in the light of experimental studies on dietary potassium restriction in man. [ABSTRACT FROM PUBLISHER]

Interleukin-8 (IL-8) attracts neutrophils into tissues and causes them to degranulate. Both menstruation and parturition involve neutrophil migration into uterine tissues and therefore IL-8 is a likely mediator of the tissue re-arrangements that accompany these events. We have examined the ability of endometrium explants and chorion cells in culture to synthesize and release IL-8 and the ability of progesterone, a synthetic progestin [medroxyprogesterone acetate (MPA)] and dexamethasone to inhibit this production. In endometrium, the stage of the menstrual cycle did not affect IL-8 production but a 10(-6) M concentration of progesterone or dexamethasone significantly reduced the concentration of IL-8 in medium after 24 h. After a further 24 h with lipopolysaccharide (LPS) stimulation, only MPA and dexamethasone inhibited production significantly. In chorion cells, IL-8 production was significantly decreased by both MPA and dexamethasone in the LPS stimulated cells but the reduction in the first 24 h was not significant. The IL-8 produced in uterine tissues might act synergistically with prostaglandin E (PGE), a likely site for this interaction being blood vessels where PGE production is also repressed by progesterone. Such a cooperative action would maintain low leukocyte entry into uterine tissues in the presence of progesterone and falling steroid levels would induce leukocyte immigration and activation with consequent tissue destruction. Such steroid-dependent interactions are important in our understanding of the mechanisms of menstruation and parturition and could allow new approaches to the treatment of uterine pathology. [ABSTRACT FROM AUTHOR]

Sixteen common biochemical estimations have been performed on nearly 500 people randomly selected from those over 65 living at home. The mean values and ranges found for serum sodium, potassium, chloride, bicarbonate, magnesium, bilirubin, inorganic phosphate, total protein, albumin, and globulin, were identical, and those of urea, creatinine, cholesterol, uric acid, calcium, and alkaline phosphatase were higher than those considered normal in younger people. Sex differences were demonstrable for serum urea, creatinine, bilirubin, phosphate, cholesterol, calcium, and alkaline phosphatase; in the last four instances these seemed likely to be of clinical importance. [ABSTRACT FROM PUBLISHER]

The article presents a case study of the two three-day-old female Dohne Merino with congenital reflex myoclonus in cross lambs in South Africa. Methods used a complete clinical examination, neurological examination, and faecal analysis, along with the collection of blood and serum for haemotology, serum chemistry, and measurement of enzyme activity. Moreover, the specific genetic and immunohistochemistry analyses are required to study the molecular neuromuscular cause in the Merino cross lambs.