Coagulants

Oily wastewaters are the most important discharges of gas refineries from an environmental point-of-view. In the present study, treatment of gas refinery oily wastewater by electrocoagulation using aluminum electrodes was investigated. The effects of electrode distance, initial pH, sodium sulfate (Na2SO4) as a supporting electrolyte, polyaluminum chloride dosage as a coagulant aid, and current density on the efficiency of chemical oxygen demand (COD) removal were examined. The results revealed that the COD removal rate increases by applying more current density and polyaluminum chloride and, to a lesser extent, Na2SO4 dosage. The results also showed that 97% COD can be removed at optimum operational conditions. Specific electrical energy consumption could be reduced from 19.48 kWh (kg COD removal)(-1) to 11.057 kWh (kg COD removal)(-1) using Na2SO4 as a supporting electrolyte. Gas chromatographic analysis of raw and treated wastewater also revealed that most normal hydrocarbons (nea...

Pseudo tumours are amongst the rare yet pathognomonic complications of haemophilia. They are old, encapsulated haematomas which due to their sometimes enormous size can cause massive complaints. These haematomas are surrounded by a thick fibrous capsule. They are attributed to persistent bleedings. The pathophysiology of pseudo tumors is not conclusively established yet. Some believe that they originate from bone material or the periosteum, while others suggest their development from soft tissue. They spread aggressively, displace the surrounding tissue, and cause secondary periosteal erosion of the bone. This results in bone resorption and destruction of surrounding muscular and soft tissue. Pseudo tumours develop slowly over many years. They occur primarily in adults and are largely unresponsive to conservative treatment. A 48-year-old man with moderate hemophiliaA (FVIII:C 2%) and no FVIII inhibitor. Due to recurrent bleeding into the muscle of the right thigh diagnosis of two ps...

The anticoagulant and estrogenic effects of prolame, N- (3-hydroxy-1,3,5(10)-estratrien-17β-yl) -3-hydroxypropylamine, are described. A single subcutaneous injection of prolame in male mice, ovariectomized mice, adult and infant male rats, produced dose-dependent increases of blood clotting time, which could be observed with the larger doses even af-ter 4 days. In ovariectomized mice, prolame produced vaginal cornifications of shorter duration than those produced by estradiol-17β. The evidence suggests that, in contrast with currently used estrogens, prolame would not generate cardiovascular accidents if used for the treatment of prostatic carcinoma; it could also exceptionally effective for the prevention of thrombosis.

SummaryPlatelets are known for their role in haemostasis where they help prevent blood loss at sites of vascular injury. To do this, they adhere, aggregate and form a procoagulant surface leading to thrombin generation and fibrin formation. Platelets also release substances that promote tissue repair and influence the reactivity of vascular and other blood cells in angiogenesis and inflammation. They contain storage pools of growth factors including PDGF, TGF-β and VEGF as well as cytokines including proteins such as PF4 and CD40L. Chemokines and newly synthesised active metabolites are also released. The fact that platelets secrete growth factors and active metabolites means that their applied use can have a positive influence in clinical situations requiring rapid healing and tissue regeneration. Their administration in fibrin clot or fibrin glue provides an adhesive support that can confine secretion to a chosen site. Additionally, the presentation of growth factors attached to p...

Seeds of the plant species Strychnos potatorum and Moringa oleifera contain natural polyelectrolytes which can be used as coagulants to clarify turbid waters. In laboratory tests, direct filtration of a turbid surface water (turbidity 15-25 NTU, heterotrophic bacteria 280-500 cfu ml(-1), and fecal coliforms 280-500 MPN 100 ml(-1)), with seeds of S. potatorum or M. oleifera as coagulant, produced a substantial improvement in its aesthetic and microbiological quality (turbidity 0.3-1.5 NTU, heterotrophic bacteria 5-20 cfu ml(-1) and fecal coliforms 5-10 MPN 100 ml(-1)). The method appears suitable for home water treatment in rural areas of developing countries. These natural coagulants produce a 'low risk' water; however, additional disinfection or boiling should be practised during localised outbreaks/epidemics of enteric infections.

Percutaneous liver biopsies are used to grade and stage liver disease and are also useful in monitoring the progress of liver disease over time as well as the response to medical therapies. The present study was undertaken to assess the effectiveness of recombinant factor VIIa as a means of transiently correcting the coagulopathy, enabling the safe performance of a percutaneous liver biopsy in patients in whom the use of fresh-frozen plasma is not possible without precipitating pulmonary edema or who have a treatment induced (iatrogenic) coagulopathy. The subjects of this report consisted of 18 consecutive individuals with advanced disease induced, and 15 with a therapeutic iatrogenic-induced, coagulopathy. All biopsies were performed by a single hepatologist. Before and 6 h after each biopsy, a prothrombin time and partial thromboplastin time was obtained from each subject. Mean values +/- the standard error of the mean were obtained using the independent samples T-test. Recombinant factor VIIa had a marked effect in transiently correcting the mean prothrombin time in these subjects allowing for a safe complication free percutaneous biopsy in this high-risk group. Recombinant factor VIIa could be used to obtain a clinically indicated liver biopsy in severely ill patients, who without this therapeutic agent, would either not be biopsied or, if biopsied, would require much longer hospitalization and the use of fresh-frozen plasma (with its risks of volume overload and infection).

The Committee of Latin America on the Therapeutics of Inhibitor Groups (CLOTTING) is composed of a number of hemophilia specialists from Latin America. The group aims to encourage the adoption of a good standard of care for Latin American patients with hemophilia. The occurrence of inhibitors in patients with hemophilia poses clinical challenges, and it is estimated that between 1000 and 3000 patients in Latin America are affected by hemophilia with inhibitors. There is an urgent need to establish a regional consensus and clinical guidelines for the diagnosis and treatment of these patients. We present an extensive review based on best current clinical practice and published literature, as seen from a Latin American perspective, taking into account the variable nature of hemophilia care available in the various countries in this Region.

A long-acting factor VIII (FVIII) as a replacement therapy for hemophilia A would significantly improve treatment options for patients with hemophilia A. To develop a FVIII with an extended circulating half-life, but without a reduction in activity, we have engineered 23 FVIII variants with introduced surface-exposed cysteines to which a polyethylene glycol (PEG) polymer was specifically conjugated. Screening of variant expression level, PEGylation yield, and functional assay identified several conjugates retaining full in vitro coagulation activity and von Willebrand factor (VWF) binding.PEGylated FVIII variants exhibited improved pharmacokinetics in hemophilic mice and rabbits. In addition, pharmacokinetic studies in VWF knockout mice indicated that larger molecular weight PEG may substitute for VWF in protecting PEGylated FVIII from clearance in vivo. In bleeding models of hemophilic mice, PEGylated FVIII not only exhibited prolonged efficacy that is consistent with the improved ...