Modification of fibrous membrane for organic and pathogenic contaminants removal: from design to application

In this study, a flexible multifunctional fibrous membrane for heterogeneous Fenton-like removal of organic and pathogenic contaminants from wastewater was developed by immobilizing zerovalent iron nanoparticles (Fe-NPs) on an amine/thiol grafted polyester membrane. Full characterization of the resulting polyester membranes allowed validation of successful grafting of amine/thiol (NH₂ or SH) functional groups and immobilization of Fe-NPs (50–150 nm). The Fenton-like functionality of iron immobilized fibrous membranes (PET–Fe, PET–Si–NH₂–Fe, PET–NH₂–Fe, and PET–SH–Fe) in the presence of hydrogen peroxide (H₂O₂) was comparatively studied in the removal of crystal violet dye (50 mg L⁻¹). The effect of pH, amount of iron and H₂O₂ concentration on dye removal was systematically investigated. The highest dye removal yield reached 98.87% in 22 min at a rate constant 0.1919 min⁻¹ (R² = 95.36) for PET–SH–Fe providing 78% toxicity reduction assessed by COD analysis. These membranes could be reused for up to seven repeated cycles. Kinetics and postulated mechanism of colour removal were proposed by examining the above results. In addition, the resultant membranes showed substantial antibacterial activity against pathogenic bacteria (Staphylococcus epidermidis, Escherichia coli) strains studied through disc diffusion-zone inhibitory and optical density analysis. These findings are of great importance because they provide a prospect of textile-based flexible catalysts in heterogeneous Fenton-like systems for environmental and green chemistry applications.

Multifunctional fibrous membrane for heterogeneous Fenton-like removal of organic and pathogenic contaminants from wastewater was developed by immobilizing zerovalent iron nanoparticles (Fe-NPs) on an amine/thiol grafted polyester membrane.     

Peritoneovenous Shunt as a Bridge to Liver Transplantation

Intractable ascites carries great morbidity. The aim of this study was to determine the efficacy of peritoneovenous shunt (PVS) in patients listed for liver transplantation (LT). Between January 1999 and January 2004, PVS was inserted in 36 (30 males and 6 females) cirrhotic patients, 50.3 years of median age (range: 30-66), who failed multiple large-volume paracenteses and diuretic therapy, when listed for LT. Data were collected until LT or the present time, and were compared to an historical cohort (1997-1998) as control. No operative death occurred. Four patients died before LT in a median delay of 9 months after PVS insertion. PVS provided palliation for intractable ascites in 30 patients (83%). Renal function significantly improved (glomerular filtration rate (GFR) improved from 0.642 to 0.987 mL/s, p<0.05). Eighteen patients were transplanted in a median delay of 6 months (range: 3-12 months) after PVS insertion. When compared to the historical cohort of 18 patients, the occurrence of post-LT acute renal failure was significantly lower in the PVS group (3/18 vs. 13/18, p<0.05). Our results suggest that PVS might be beneficial in patients with refractory ascites waiting for LT and could prevent postoperative acute renal failure.     

Surface modification of biomaterials based on cocoa shell with improved nitrate and Cr(vi) removal

The present work addresses the development of simple, low-cost and eco-friendly cocoa-shell-based materials for efficient removal of heavy metal hexavalent chromium (Cr(vi)), and toxic nitrate (NO₃⁻) from aqueous solution. A conventional treatment process was used to purify cocoa shell (CS) into an adsorbent, followed by chemical grafting of dendrimers to promote its surface properties for nitrate and Cr(vi) removal. The morphology, surface charge, structure and stability of the new adsorbent were investigated by scanning electron microscopy, Fourier transform infrared and UV-visible spectroscopies, zeta potential, X-ray photoelectron spectrometry, and differential scanning calorimetry. The successful chemical grafting of the dendrimer (polyethyleneimine, PEI) onto purified CS was confirmed. CS-T-PEI-P proved to be a very efficient candidate for the removal of nitrate and chromium(vi). Removal of the two pollutants at different initial concentrations and pH values was studied and discussed. Sorption of chromium and nitrate was found to obey 2^nd-order kinetics and a Freundlich-type isotherm, affording an uptake adsorption of 16.92 mg g⁻¹ for NO₃⁻ and 24.78 mg g⁻¹ for Cr(vi). These results open promising prospects for its potential applications as a low cost catalyst in wastewater treatment.

The present work addresses the development of simple, low-cost and eco-friendly cocoa-shell-based materials for efficient removal of heavy metal hexavalent chromium (Cr(vi)), and toxic nitrate (NO₃⁻) from aqueous solution.     

Hemodynamic tolerance and rapid hypertrophy of a hepatic graft corresponding to less than 30% of the ideal mass in pigs

BACKGROUND AND OBJECTIVE: Evaluation of a new pig liver transplantation technique for survival and hypertrophy of a small-sized graft by providing adapted and controlled venous portal flow. MATERIAL ET METHODS: Twenty Large-White pigs underwent heterotopic liver transplantation after a mesocaval shunt and ligation of the superior mesenteric vein downstream from the shunt. The donor-to-recipient weight ratio was below 30%. Furthermore, recipient's biliary duct and portal vein into the hilum were tied. In a control group, no mesocaval shunt was performed and the graft received the entire splanchnic venous flow. RESULTS: The mesocaval shunt provided diversion of 60% of the splanchnic blood flow. The median survival of study pigs was 39 days (range: 8-98). Median serum bilirubin levels at 1 week were 12 micromol/L (range: 4-59). At autopsy, graft weight was increased to 2.7 times the initial weight and histological findings were normal. In the control group, all pigs died quickly from acute splanchnic congestion. CONCLUSION: In a model of heterotopic liver transplantation using small-sized grafts, complete diversion of mesenteric blood flow through a mesocaval shunt resulted in hemodynamic tolerance and hypertrophy of a graft corresponding to less than 30% of the ideal mass.     

Favorable outcome of liver transplantation despite a high hepatitis B virus replication: beyond the limits?

Patients with end-stage liver disease due to chronic hepatitis B virus (HBV) infection with a persistent viral replication are generally denied liver transplantation (LT). We report the case of a patient who presented with the emergence of a YMDD escape mutant virus under lamivudine treatment, and developed terminal liver failure requiring LT. Pre-LT introduction of adefovir led to only a mild decrease in replication. The patient was treated with a combination of intravenous hepatitis B immune globulin (HBIG) that was started perioperatively, and also continued lamivudine and adefovir after LT. One year after LT, there was no evidence of HBV infection recurrence. This observation suggests that persistent high HBV replication might not be a contra-indication to LT, providing adequate and effective prophylaxis is given, using HBIG and antiviral drug combination therapy.     

Pharmacokinetics and Tissue Distribution of Recombinant Human Transforming Growth Factor Beta1 After Topical and Intravenous Administration in Male Rats

Recombinant human transforming growth factor beta (rhTGF-₁) enhances the healing process after topical application to various animal wound models. A detailed pharmacokinetic and tissue distribution study was performed to support the clinical development of rhTGF-₁ for wound healing indications. Rats received radioiodinated or unlabeled rhTGF-₁ as an intravenous (iv) bolus or as a topical formulation applied to a full thickness wound. Plasma concentrations of TGF-₁ were estimated from TCA-precipitable radioactivity or were measured by ELISA. Following iv administration, the initial half-life was rapid (<11 min), regardless of whether radi-olabeled or unlabeled rhTGF-₁ was used. The terminal half-life was long (163 min) when the test material was radioiodinated and administered as a trace dose and relatively short (61 min) when given at high doses and assayed by ELISA. Analysis of plasma radioactivity by SDS-PAGE revealed a time-dependent clearance of the 25-kDa parent molecule without a significant appearance of lower molecular weight radiolabeled metabolites. The majority of the radioactivity was associated with highly perfused organs, known iodide elimination pathways, and the thyroid at 1 and 8 hr after iv injection. After topical administration of a high dose (0.8 mg/kg), no immunoreactive TGF-₁ was detectable in plasma samples taken over a 48-hr period. However, trace amounts (0.05 ng/mL) of acid-precipitable radioactivity were detected in plasma after topical application of [¹²⁵I]rhTGF-₁ (1 µg/kg, 126 µCi/kg). A significant portion (35%) of the [¹²⁵I]rhTGF-₁ persisted intact (25 kDa) at the wound site 24 hr after application. In conclusion, rhTGF-₁ was rapidly cleared after iv bolus administration and distributed primarily to the liver, lungs, kidney, and spleen. Little systemic exposure was observed after applying a single topical dose of rhTGF-₁ to a wound, and the intact molecule persisted at the wound site.     

Liver transplantation in infants and children. Evaluation of the first 40 cases (March 1991-March 1997)]

BACKGROUND: Liver transplantation (LT) is the treatment of end-stage liver disease in children. We report our experience with LT using grafts from living related (LRD) and cadaver donors (CD). POPULATION: From March 1991 to March 1997, 40 children and infants received a total of 42 liver grafts. A reduced-size liver was used in 28 cases. We studied pre-transplantation status, survival rate, and medical and surgical complications in these patients. RESULTS: The survival rate in our series was respectively 85 and 80% at 1 and 7 years after LT. Low weight infants required a prolonged ventilatory assistance. Five of the six deaths noticed during the first three months after LT occurred in children weighing less than 12 kg. One year after LT, no significant difference in the incidence of rejection was found, neither between low-weight children and the others, nor between patients transplanted from CD or LRD. Biliary tract stricture was the major surgical complication. CONCLUSION: This series consisted of a majority of low-weight children. The survival rate in the patients weighting less than 12 kg is lower than in the others. This may be explained by the nutritional status of these patients and early postsurgical complications. The use of grafts from living donors offers more flexibility since the operation is performed electively, but it did not seem to modify the incidence of acute rejections and surgical complications.     

Safety and antitumor activity of recombinant soluble Apo2 ligand

TNF and Fas ligand induce apoptosis in tumor cells; however, their severe toxicity toward normal tissues hampers their application to cancer therapy. Apo2 ligand (Apo2L, or TRAIL) is a related molecule that triggers tumor cell apoptosis. Apo2L mRNA is expressed in many tissues, suggesting that the ligand may be nontoxic to normal cells. To investigate Apo2L's therapeutic potential, we generated in bacteria a potently active soluble version of the native human protein. Several normal cell types were resistant in vitro to apoptosis induction by Apo2L. Repeated intravenous injections of Apo2L in nonhuman primates did not cause detectable toxicity to tissues and organs examined. Apo2L exerted cytostatic or cytotoxic effects in vitro on 32 of 39 cell lines from colon, lung, breast, kidney, brain, and skin cancer. Treatment of athymic mice with Apo2L shortly after tumor xenograft injection markedly reduced tumor incidence. Apo2L treatment of mice bearing solid tumors induced tumor cell apoptosis, suppressed tumor progression, and improved survival. Apo2L cooperated synergistically with the chemotherapeutic drugs 5-fluorouracil or CPT-11, causing substantial tumor regression or complete tumor ablation. Thus, Apo2L may have potent anticancer activity without significant toxicity toward normal tissues.