In Vitro Cytotoxicity of Zinc Fructoborate, a Novel Zinc-Boron Active Natural Complex.

In recent years, the role of zinc in biological systems has been a subject of intense research. Zinc is required for multiple metabolic processes as a structural, regulatory, or catalytic ion. The objective of this study, was to assess the toxicity profile of a newly synthesized zinc-boron molecule on cultured cells. Zinc fructoborate, at different levels of concentration, was tested for its impact on the Vero kidney cell line (ATCC® CCL-81™) using the MTT assay. The compound exhibited a low cytotoxic effect on the cell line. Thus, our study demonstrates that the zinc fructoborate could become a promising dietary supplement molecule.

Transfection-capable polycationic nanovectors which include PEGylated-cyclodextrin structural units: a new synthesis pathway.

Efficient tools are still being searched for to substitute the viral vectors in nucleic acid delivery applications. One of the most severe constraints in producing them is related to the strict reproducibility of their molecular characteristics, which is ensured through the synthesis. In this work, we report an original route to obtain polycationic nanoentities with low variability, which are able to act as cooperating carriers for dsDNA complexation and transport. The carriers are synthesized by rigorous conjugation of ß-cyclodextrin (ß-CD) with precise ratios of 2 kDa branched poly(ethyleneimine) (b-PEI) and 0.75 kDa poly(ethylene glycol) (PEG). Low cytotoxicity was the key parameter of the carrier design, besides the highest possible transfection ability, and both of these features were proven by HeLa cell culture assays. A reporter gene which induces the expression of green fluorescent protein (GFP), inserted in a plasmid, was used to perform the necessary quantitative measurements. In silico molecular modelling guided the carrier design and confirmed the functional mimicry of histones in the tight and compact nucleosome-like spiral packaging of dsDNA. The carrier molecules, synthesized with high reproducibility, are expected to be feasible for application in gene transfection.

Biocompatibility testing of chitosan hydrogels.

UNLABELLED: Chitosan is a linear, natural cationic polysaccharide comprising beta-1,4 linked glucosamine and N-acetyl-D-glucosamine. Hydrogels of chitosan were prepared by crosslinking with varying amounts of glutaraldehyde. It can be used as a bacteriostatic, fungistatic and coating agent, and the gels and suspensions may play the role of carriers for slow release or controlled delivery of drugs, as an immobilizing medium and an encapsulation material. MATERIAL AND METHODS: Chitosan and glutaraldehyde were used to prepare the hydrogels and their characteristics were investigated by Fourier transform infrared (FT-IR) spectroscopy and the inhibitory effect on cellular growth was tested by chemiluminescence assay. The hemolytic activity was also determined by direct contact with human blood and the concentration of hemoglobin was spectrophotometrically measured. RESULTS AND DISCUSSION: Chitosan hydrogels have no inhibitory effect on cell growth, and hemolytic action below 1%, which means good blood compatibility; therefore they are promising materials.

Modelling of ion permeation in K+ channels by nonequilibrium molecular dynamics simulations: I. Permeation energetics and structure stability.

Because of the great importance of physiological and pathophysiological processes in which ion channels are involved and because their operation is described by physicochemical laws, there have been many attempts to develop physical models able to describe the membrane permeability and also the structural and functional properties of the channel protein structures. In this study (in two parts) we present a series of simulations on a K+ channel model (KcsA) using Nonequilibrium Molecular Dynamics simulations (NEMD), in order to follow structure stability, permeation energetics and the possibility of obtaining quantitative information about the permeation process using the Linear Response Theory (LRT). On K+ ions were applied external forces to determine them to pass through the channel in a relatively small amount of time, accessible computationally. We ascertained a high resistance of the protein to deformation even in conditions when great forces were applied on ions (the system was far from equilibrium). The estimation of energy profiles in the course of ions passage through the channel demonstrates that these proteins create a conductivity pathway with no energetic barriers for ions movement across the channel (which could be present due to ions dehydration). The dynamic model used demonstrates (as proposed before in the literature after the examination of the static KcsA structure obtained by X-Ray crystallography) that this is due to the interaction of ions with the negatively charged carbonyl oxygens of the main polypeptide chain in the selectivity filter region.

Infections with hepatitis B and C viruses in patients on maintenance dialysis in Romania and in former communist countries: yellow spots on a blank map?

We studied prospectively, between 1993 and 1998, the prevalence and incidence of markers against hepatitis B virus (HBV), hepatitis C virus (HCV) and hepatitis D virus (HDV), in 180 patients with chronic renal failure, dialysed in the Nephrological Clinic, Cluj. HBV and HCV markers were common in the patients who were already on haemodialysis in 1993 (antibodies to hepatitis B core antigen [HBcAb]: 57.9-88%; hepatitis B surface antigen [HBsAg]: 8.7-25%; antibodies to HCV [anti-HCV]: 73.7-100%; simultaneous occurrence of HBsAg and anti-HCV antibodies: 4.4-21%). These patients had the longest mean duration of haemodialysis therapy (6.79 +/- 4.82 years). The lowest prevalence was found in 1996, in the groups of patients included in the haemodialysis programme between 1993 and 1996 (HBcAb: 2.2-3.3%; HBsAg: 0-2.2%; anti-HCV antibodies: 0-2.2%; HBsAg and anti-HCV antibodies: 0-2.2%). The patients included since 1996 had, again, a high prevalence of markers (HBsAg: 21.6%; anti-HCV antibodies: 28.6%), despite the short duration of dialysis therapy (1.65 +/- 1.18 years). The incidence of infection was high before 1993, fell markedly between 1993 and 1996 (zero for the HBsAg and 6. 67% year-1 for the anti-HCV antibodies) and rose sharply between 1996 and 1998 (10.2%, respectively 29% year-1). The prevalence of HBV and HCV infections did not correlate with the age of the patients and depended, but only up to 1993, on the quantity of transfused blood. The link between the duration of the haemodialysis and the prevalence of the HBV and/or HCV infection proved nosocomial transmission. The very high prevalence and incidence of HBV and HCV infections, surpassing not only Western countries, but even those of 'developing' countries that are endemic for these infections, is characteristic of some former communist countries. A radical reform of the medical system in these countries is required.

[The prevalence of hepatitis C and B viral markers in patients with sexually transmitted diseases in Cluj]. / Prevalenta markerilor virusurilor hepatitice C si B la pacientii cu boli cu transmisie sexuala din Cluj.

BACKGROUND: Recently, hepatitis C virus (HCV) have been recognised as being one of the most important cause of non-A, non-B hepatitis. Although parenteral transmission of HCV is wellknown, the risk of sexual transmission is still under debate. OBJECTIVE: This study was conducted to assess the HCV infection markers in sexually transmitted disease (STD) patients from an endemic area for hepatitis B virus (HBV) infection. Additionally, we studied the prevalence of HBV infection markers in these patients. PATIENTS AND METHODS: The sera of 121 patients with STD from Cluj-Napoca have been tested for antibodies to HCV (anti-HCV), Hbs antigen (Hbs Ag), antibodies to Hbc antigen (anti-HBc), by automated ELISA. RESULTS: Anti-HCV were detected in 26/121 (21.5%) patients: 73/121 (60.3%) patients presented HBV infection markers HBV infection markers (HbsAg and or anti-HBc) have been observed in 22/26 (84.6%) HCV infected patients. CONCLUSIONS: Prevalence of HCV infection markers in STD patients from Cluj is high (21.5%). HBV infection markers have been detected in 60.3% of patients. In STD patients form Cluj HCV infection markers have been correlated to HBV infection markers.

[The role of the hepatitis B, C and D viruses in the etiology of chronic hepatopathies in Cluj]. / Rolul virusurilor hepatitice B, C si D in etiologia hepatopatiilor cronice din Cluj.

OBJECTIVE: We studied the prevalence of viral hepatitis B, C and D markers in chronic hepatopathies from Cluj. MATERIAL AND METHODS: Sera of 297 patients with chronic hepatopathies (236 adults and 61 children) have been tested for viral hepatitis markers: HBsAg, anti-HBc, anti-HBs, HBeAg, anti-HBe, anti-HDV, anti-HCV, by automated ELISA. RESULTS: HBV infection markers in 32% (adults) and 4.9% (children), and HDV infection markers in 11.8% (adults) and 26.3% (children). Double (HBV and HCV) and triple infection (HBV, HDV and HCV) were observed in 28.4% (adults), 4.9% (children), and 3.4% (adults), 0% (children), respectively. CONCLUSIONS: Hepatitis virus infection markers, especially HBV and HCV play an important role in the determinism of chronic hepatopathies from Cluj area, both in children and adults.

[The markers of hepatitis B, C and D viral infection in multiply transfused patients]. / Studiul markerilor infectiei cu virusurile hepatitice B, C si D la politransfuzati.

OBJECTIVE: We aimed to assess the seroprevalence of HBV, HCV and HDV virus markers in multi-transfused patients from Cluj-Napoca. MATERIAL AND METHODS: Stored serum samples of 105 multi-transfused patients (25 children, 19 adults and 61 chronically hemodialyzed patients) have been tested for HBsAg, anti-HBs, total anti-HBc, anti-HCV, total anti-HDV by automated ELISA (Sanofi Diagnostics Pasteur kits). RESULTS: HVC infection has been observed in 4/25 (16%) children, 14/19 (74%) multi-transfused adults and 48/61 (79%) haemodialysis patients. 8/25 (32%) children, 17/19 (89%) adults and 47/61 (77%) haemodialysis patients had HBV infection markers. Anti-HDV have not been found in HBV infected multi-transfused children and adults, respectively. Only 2/47 (4.25%) HBV infected haemodialysis patients had HDV infection markers. The prevalence of double infection (HCV and HBV) was high (4%, 84.2% and 67.2% in children, adults and haemodialysis patients). The prevalence of viral hepatitis markers correlated to the amount of transfused blood, and in haemodialysis patients also correlated to the duration on dialysis. CONCLUSIONS: In multi-transfused patients from Cluj area, the prevalence of viral hepatitis markers is high. The double infection (HCV and HBV) is frequent, especially in adults. The prevalence of HDV infection markers in HBV infected patients is low, in contrast with previously reported results.