Artificial blood feeding for Culicidae colony maintenance in laboratories: does the blood source condition matter?

Culicidae colonization in laboratory is paramount to conduct studies aiming at a better understanding of mosquitoes' capacity to transmit pathogens that cause deadly diseases. Colonization requires female blood feeding, a necessary step for maturation of female's oocytes. Direct blood feeding on anesthetized mammals implies in a number of disadvantages when compared to artificial blood feeding. Consequently, laboratories worldwide have been trying to -feed female mosquitoes artificially in order to replace direct feeding. In this study, we compared the effects of direct blood feeding and artificial blood feeding on important life traits of three Culicidae species. Artificial feeding was performed using citrated or defibrinated sheep blood and citrated or defibrinated rabbit blood. Direct feeding was performed using anesthetized guinea pigs as the blood source and the experiment control. Results indicated that artificial feeding using sheep blood was not good enough to justify its use in the maintenance of laboratory colonies of Culicidae. However, artificial feeding using rabbit blood maintained a recovery rate always very close to the control, especially when blood was citrated. We concluded that artificial feeding using citrated rabbit blood can substitute direct feeding on mammals reducing the use of animals, eliminating the need to maintain a bioterium in the laboratory and reducing costs in scientific researches involving Culicidae vectors.

Comparison of blood product use and costs with use of 3-factor versus 4-factor prothrombin complex concentrate for off-label indications.

PURPOSE: Results of a comparison of blood product use and cost outcomes with use of 3-factor versus 4-factor prothrombin complex concentrate (PCC) for indications other than warfarin reversal are presented. METHODS: Consecutive patients who received 3-factor PPC (PCC3) or 4-factor PCC (PCC4) for non-warfarin-related indications at 2 U.S. hospitals during a 19-month period were identified. The primary outcome was in-hospital blood product use, with a focus on plasma use. Total hemostasis costs, intensive care unit (ICU) and hospital lengths of stay, and other outcomes were evaluated. RESULTS: Indications for PCC3 use (n = 118) or PCC4 use (n = 64) included intraoperative bleeding, nonintraoperative bleeding, coagulopathy of liver disease, and reversal of direct-acting oral anticoagulant effects. The proportion of patients who received plasma was 56.8% with PCC3 use versus 53.1% with PCC4 use (p = 0.643); the corresponding median volumes of plasma received were 638 mL (interquartile range [IQR], 550-1,355 mL) and 656 mL (IQR, 532-1,136 mL), respectively. The median total hemostasis costs were $5,559 (IQR, $3,922-$8,159) with PCC3 use and $7,771 (IQR, $6,366-$9,205) with PCC4 use (p < 0.001). CONCLUSION: PCC3 use and PCC4 use were associated with similar blood product use, ICU length of stay, hospital length of stay, and in-hospital mortality when given for non-warfarin-related indications. However, relative to PCC3 use, PCC4 use was associated with an increase in costs that was primarily due to drug costs.

An Artificial Cadaveric Leg Blood Flow System for Endoscopic Vein Harvesting Simulation.

Despite being the most common training model for endoscopic vein harvesting, cadaveric legs are limited by their absence of blood flow, resulting in a faded vascular appearance. Because the saphenous vein and the surrounding tissue seem less distinguishable, dissection of the saphenous vein and bipolar coagulation of its branches becomes increasingly inefficient and difficult. An inexpensive artificial blood flow system was developed to overcome this limitation. A cadaveric leg was thawed to a soft and yielding degree, and the saphenous vein was dissected medial and proximal to the medial malleolus. An artificial blood solution was prepared by dissolving 4% protein powder, red dye, and a contrast agent-for x-ray visualization-in saline. The solution was perfused through the saphenous vein and artery. The open ends of the vessels were temporarily clamped after the perfusion had been completed. Blood flow within the vessels was confirmed via angiography and endoscopic visualization of the leg's vessels. A bleeding effect was observed when the saphenous vein was perforated or when a vascular branch was transected. Conversely, a tight seal indicated successful bipolar coagulation of a branch, providing an objective, quantifiable assessment parameter. The artificial blood flow system helps overcome the limitations of the cadaveric leg, creating a more realistic and inexpensive model for endoscopic vein harvesting simulation training.

Alternatives to allogeneic blood transfusions.

Inherent risks and increasing costs of allogeneic transfusions underline the socioeconomic relevance of safe and effective alternatives to banked blood. The safety limits of a restrictive transfusion policy are given by a patient's individual tolerance of acute normovolaemic anaemia. latrogenic attempts to increase tolerance of anaemia are helpful in avoiding premature blood transfusions while at the same time maintaining adequate tissue oxygenation. Autologous transfusion techniques include preoperative autologous blood donation (PAD), acute normovolaemic haemodilution (ANH), and intraoperative cell salvage (ICS). The efficacy of PAD and ANH can be augmented by supplemental iron and/or erythropoietin. PAD is only cost-effective when based on a meticulous donation/transfusion plan calculated for the individual patient, and still carries the risk of mistransfusion (clerical error). In contrast, ANH has almost no risks and is more cost-effective. A significant reduction in allogeneic blood transfusions can also be achieved by ICS. Currently, some controversy regarding contraindications of ICS needs to be resolved. Artificial oxygen carriers based on perfluorocarbon (PFC) or haemoglobin (haemoglobin-based oxygen carriers, HBOCs) are attractive alternatives to allogeneic red blood cells. Nevertheless, to date no artificial oxygen carrier is available for routine clinical use, and further studies are needed to show the safety and efficacy of these substances.

[Health economic aspects of the use of blood and blood products]. / Gesundheitsökonomische Aspekte der Anwendung von Blut- und Plasmaprodukten.

An adequate supply of blood components for patients depends on the population's willingness to donate blood as well as on a well-organized blood donation system. In order to ensure the blood supply, a high expenditure is necessary. The article at hand describes two areas of the use of blood and blood products. First, it considers the application of factor concentrates in haemophiliacs (approximately 3000-4000 patients are regularly in need of treatment). For the German statutory health insurance, the estimated yearly expenses for factor concentrates is approx. 450 million Euros, the average costs per patient and year and per treatment center range between 40,903 and 117,597 Euros. The costs for an immune tolerance therapy (ITT) for patients with inhibitors are estimated to be between 70,300 and 3,800,000 Euros for children, depending on the length of the therapy and the degree of severity. In the second part of the article, the authors outline the status quo of the economic evaluation of cellular blood products and present the results of a German cross-sectional survey on the use of erythrocytes in orthopaedic surgery. Within the scope of this hemotherapy study, the transfusion rates vary considerably within the participating treatment centers [elective hip joint replacement (THR): 17 and 94%]. The average blood loss also differs significantly. Comparing the treatment centers, the calculated blood loss during THR shows considerable differences (median blood loss in treatment center with lowest/treatment center with highest blood loss: 883 ml/2,975 ml). The acceptance of low intraoperative hemoglobin values in the clinics is high and diverse. These differences in transfusion procedures between the treatment centers clearly show the need to take effective action in the area of quality assurance in order to make the most of the existent savings potential. Transparency of treatment processes is a necessary condition for an economic assessment and for optimal resource allocation.

[Artificial oxygen carriers as an alternative to red blood cell transfusion]. / Künstliche Sauerstoffträger als Alternative zur Bluttransfusion.

The expected cost-explosion in transfusion medicine (increasing imbalance between donors and recipients, treatment of transfusion-associated complications) increases the socio-economic significance of the development of safe and effective synthetic oxygen carriers as an alternative to the transfusion of allogeneic red blood cells. Currently two types of artificial oxygen carriers have been tested for safety and efficacy in cases of severe anemia otherwise requiring transfusion. Solutions based on human or bovine hemoglobin (HBOC) possess vasoconstrictor properties in addition to their oxygen transport capacity. The impact of vasoconstriction on tissue perfusion and organ function is however not yet fully understood. Nevertheless, in 2001 the bovine HBOC Hemopure was approved in South Africa for treatment of acutely anemic surgical patients. The purely synthetic perfluorocarbon (PFC) emulsions increase the physically dissolved portion of arterial oxygen content. Due to their particulate nature (emulsion droplets) PFCs may only be infused in low doses to avoid overload and malfunction of phagocytic cells of the reticulo-endothelial system. As part of a multimodal blood conservation program (including normovolemic hemodilution and hyperoxia) the low-dose administration of Oxygent effectively increases intraoperative anemia tolerance. Although reduction of perioperative allogeneic blood transfusion has already been demonstrated for HBOC and PFC, the global clinical establishment of artificial oxygen carriers is not to be expected in the near future.

Oxygen carriers ("blood substitutes").

(1) A number of oxygen carriers, or "blood substitutes", are undergoing clinical trials. One product (Hemopure(R)) was recently licensed for use in South Africa. Another, (Hemolink(tm) may soon be approved for marketing in Canada. (2) Most trials of oxygen carriers have focused on their use in surgery, primarily as a way to minimize the need for allogeneic blood transfusion. (3) The benefits of these products in comparison with other blood conservation technologies and with allogeneic blood transfusion must be determined. (4) The safety and cost-effectiveness of these products, and the patient populations that would benefit most from their use require further study.

Alternatives to standard blood transfusion: availability and promise.

Largely due to concerns over safety, a wide variety of alternatives to the conventional blood bank products of red cells, platelet concentrates, plasma and fractionated plasma products are under development. This review attempts to survey the alternative therapies that are being developed, whether they provide viable solutions and what impact they might have on transfusion practice.