Physical characterization, biocompatibility, and antimicrobial activity of polyvinyl alcohol/sodium alginate blend doped with TiO2 nanoparticles for wound dressing applications.

The ability of wound dressing materials to tackle skin pathogens colonization that is associated with open wound infections is limited. Recently, green-synthesized metal oxide nanoparticles has received a lot of attention to overcome this limitation. However, titanium dioxide nanoparticles (TiO2-NPs) exhibit exceptional antibacterial properties. In this work, several concentrations (0, 1, 3, and 5 wt.%) of TiO2 NPs prepared using Aloe vera leaf extract were added to a blend of polyvinyl alcohol and sodium alginate (PVA:SA). This nanocomposite was designed to enhance the healing process of wounds. The interaction between the PVA:SA composite and the TiO2 NPs was confirmed by FTIR. The thermal behavior of the nanocomposite films was investigated using DSC and TGA. The experimental results indicate that the glass transition temperatures of the nanocomposites increased by increasing the added amount of TiO2 NPs to be 53.7 °C (1 wt.%), 55.8 °C (3 wt.%), and 60.6 °C (5 wt.%), which were consistently lower than the glass transition temperature of the matrix material (69.6 °C). The Dynamic Mechanical Analysis was examined. The nanocomposite doped with 5 wt.% of TiO2 NPs detected a high storage modulus (21.6 × 108). Based on swelling and degradation studies, the prepared PVA:SA:TiO2 nanocomposite films have an excellent swelling rate, and the inclusion of TiO2 NPs increases the stability of the polymeric matrix. The PVA:SA:TiO2 nanocomposite films exhibited a superior antibacterial efficacy against Gram-positive bacteria such as Bacillus cereus and Staphylococcus aureus, compared to their effectiveness against Gram-negative bacteria like Escherichia coli. Moreover, the nanocomposite films were biocompatible with Human Skin Fibroblast. Therefore, the developed PVA:SA:TiO2 nanocomposite films suit wound dressing applications.

Predictors of large volume paracantesis induced circulatory dysfunction in patients with massive hepatic ascites.

PURPOSE: In patients with massive ascites, large volume paracentesis may be associated with complications as circulatory dysfunction. Selection of appropriate patients might reduce such side effects. PATIENTS AND METHODS: Forty-five patients known to have liver cirrhosis and presenting with massive ascites were included. There were 27 males and 18 females, with age (mean 51.2+10.64). All patients were subjected to full history, clinical examination, complete blood picture, prothrombin time, serum albumin, total plasma protein, serum bilirubin, serum creatinine, serum electrolytes and plasma renin activity measured by radioimmunoassay. Echocardiographic evaluation for cardiac output, pulmonary artery pressure, diastolic and systolic function before and after paracentesis. Large-volume paracentesis (LVP) ranging 8-18 liters with a mean 9.9 L was performed to all patients. Paracentesis induced circulatory dysfunction (PICD) was defined as increase in plasma renin activity (PRA) of more than 50% of pretreatment value to a level greater than 7.5ng /ml/ hour on the 6th day after paracentesis. RESULTS: The incidence of PICD in patients with massive hepatic ascites was 73.3% (87.5% with Dextran and 38.5% with albumin). There were no serious systemic or local side effects one week following LVP. Type of plasma expander and younger ages were the only independent predictors (odd ratio OR with 95% confidence interval CI, 3.01<21.79<157.58 and 0.80<.88<.97 respectively) Gender and other clinical and laboratory parameters had no influence. Neither electrolytes levels nor hematocrite value had an influence. Ascitic patients showed higher heart rate and cardiac output and lower arterial pressure that was accentuated after LVP (P < 0.01). Echocardiographic diastolic function, A wave velocity and deceleration time of the E wave were markedly increased in cirrhotic patients with tense ascites and the E/A ratio was markedly reduced (0.9 ± 0.3) but was not significantly affected by LVP. Ejection fraction had similar values of the normal patients with a tendency to increase after paracentesis. There were no changes in the left ventricular wall thickness. CONCLUSION: LVP is a safe and effective procedure for treatment of tense/refractory ascites. PICD is a frequently occurring silent complication following LVP. Salt free human albumin should be the plasma expander of choice especially if at least 8 liters are evacuated. Left ventricular diastolic function is altered in cirrhosis with tense ascites. This may represent an early stage of hepatic cardiomyopathy but was not affected by LVP and this was not reflected on the occurrence of PICD.

Epidermal growth factor in patients with schistosomal and/or viral liver diseases and portal hypertension.

A large number of growth factors have been described and their action and interaction is proving to be complex. The presence study estimated the epidermal growth factor (EGF) in portal hypertension patients with chronic liver disease due to bilharziasis or viral infection as well as in patients with peptic ulcers. The results showed different statistical values regarding liver cirrhosis, oesophageal varices, and bleeding. No doubt, the EGF was indirectly stimulated by the schistosomal and/or viral infection.

Progress in the measurement of ciliary beat frequency by automated image analysis: application to mammalian tracheal epithelium.

The investigations on the activity of respiratory ciliae in vivo are of considerable interest for the study of physiopathological disorders resulting from chronic infection or inhaled pollutants. We present an image analysis method for the measurement of ciliary beat frequency on mammal or human in vivo samples. Videofilm sequences of samples placed under the microscope were analyzed frame by frame by image analysis. The operator defines on the screen several areas of interest on the cell apex. The variation of grey levels in each areas allows the calculation of ciliary beat parameters. This method permits one to investigate the effects of pharmacological agents or noxious pollutants on ciliae beating and the physiological causes underlying them. Our results on rabbits were in agreement with the data published in literature, showing no significant difference between intratracheal frequencies obtained at medium and lower levels. The upper level near the cracoid cartilage has shown a greater variability than the other two levels with higher beating frequencies, a difference of likely physiological importance.

Radio-immuno assay estimation of plasma endothelin levels in patients with bilharzial and post viral liver cirrhosis: a possible new additive factor in aggravation of portal hypertension.

Radio immunoassay estimation of plasma endothelin level was carried out in 90 patients with bilharzial and post viral chronic liver diseases with portal hypertension associated with bleeding and non bleeding oesophageal varices as well as 10 normal control subjects. It was found that plasma endothelin level was significantly elevated in such patients when compared to normal controls. Moreover, there was a positive correlation between the elevated levels of plasma endothelin and portal vein diameter as well as bleeding oesophageal varices. It may be concluded that plasma endothelin, which is a very potent vasoconstrictor for both systemic and portal circulation, plays an important role in aggravation of portal hypertension in liver cirrhosis.

In vitro quantification by image analysis of inotropic and chronotropic effects of drugs on cultures of cardiac myocytes.

Quantitative image analysis is used to measure the inotropic and chronotropic effects of drugs on cultured heart cells maintained at 37 degrees C on the stage of an inverted light microscope, and sequentially superfused with control and treatment media. The beating of the cardiac myocytes is evaluated by simultaneously selecting up to eight areas, including cell edges, from digitized video image. The sizes and positions of these areas are controlled by the operator. To analyze the motion of cell edges in each area, the computer measures the shift of the mass center of pixels' grey levels. Finally, a few parameters are calculated for the eight areas and displayed graphically. In order to assess treatment effects, appropriate statistical tests are performed on the data. Image analysis is an efficient screening test for evaluating the pharmacologic or toxic effects of a substance on isolated or cultured cardiac myocytes from various species.