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D Neurath

Publications and source records attributed to D Neurath.

10 recordsLinked to original sources
PubMed2006

ADAMTS-13 levels in fresh, stored, and solvent detergent treated plasma.

BACKGROUND: ADAMTS-13 is implicated in the pathophysiology of thrombotic thrombocytopenic purpura (TTP). Plasma exchange is thought to be effective through removal of a harmful substance or provision of a required material such as ADAMTS-13. As various methods are used to prepare plasma we determined the effects of storage and solvent detergent treatment on the ADAMTS-13 levels in plasma. METHODS: Samples from fresh plasma and fresh frozen plasma (FFP) were stored at 22 degrees C and ADAMTS-13 levels were measured at 0, 12, 24, 48 and 72 h. Samples were also taken from solvent detergent treated plasma (SDP) and cryosupernatant plasma (CSP). Total protein, albumin, fibrinogen and immunoglobulins were also measured. RESULTS: In fresh plasma, the levels of both the 175 and 140 Kd subunits of von Willebrand factor were consistent at 1.38 and 1.35 OD units from 0 to 48 h indicating normal ADAMTS-13 activity. The Vitex SDP produced slightly more of the 140 Kd subunit than did Octapharma SDP which gave equivalent fragments. Cryosupernatant plasma was the same as normal plasma. None of these values changed over 48 h. There was a 28% decrease in FVIII in fresh plasma over 24 h. Fibrinogen and albumin were unchanged. CONCLUSION: ADAMTS-13 levels are not significantly decreased by storage of plasma at room temperature for up to 48 h. Both CSP and SDP also contained essentially normal levels of ADAMTS-13 and therefore could be used for treatment of patients with TTP.

ADAM Proteins↗
PubMed2006

Cryoprecipitate production: the use of additives to enhance the yield.

Cryoprecipitate is still widely used to treat hemophilia A in developing countries. However, the yield of factor VIII is relatively low averaging, i.e. only 50%. We have attempted to enhance the yield by adding sodium citrate to the plasma following the method of Shanbrom and Owens (Blood 98, 2001, 60a). Fresh-frozen plasma (FFP) units were processed either as control plasma or after the addition of 10% sodium citrate. Cryoprecipitate was produced from both. After resuspension, calcium chloride was added to the citrated cryoprecipitate to correct for excess citrate prior to testing. The levels of FVIII and fibrinogen were determined in both preparations. The citrated cryoprecipitates had varying yields of fibrinogen and FVIII in the cryoprecipitate. The FVIII levels varied from 34% to 215% recovery. Fibrinogen ranged from 55.5% to 121.4%. We found that the addition of increasing amounts of CaCl2 to normal plasma raised the FVIII values from 1.0 to 4 U/ml. To determine the possibility of assay influence we added different quantities of CaCl2 to control plasma and measured the FVIII and activated partial thromboplastin time levels. Addition of citrate to plasma resulted in an increased total amount of cryoprecipitate much of which was citrate. Assays showed considerable ranges in the quantity of FVIII and fibrinogen. Activation of FVIII can be caused by addition of excess calcium.

Calcium Chloride↗
PubMed2006

A review of nearly two decades in an autologous blood programme: The rise and fall of activity.

Autologous blood donation (ABD) has been widely recommended. Data from one of the oldest hospital-based programmes in Canada describe both activities and drawbacks. Data were compared over the nearly two decades of activity that peaked in 1996. A 5-year review of recent activity showed that of the 2410 patients referred for consideration, 1823 (75.64%) were accepted into the programme. Surgical services requested 5825 units of autologous blood. Of these, 3147 units were donated by 1536 patients, 803 units were transfused in the operating room and 558 units were given postoperatively. In total, only 1361 units (43.25%) were transfused. The mean age of the patients was 58 years (median 61 years and mode 69 years). The haemoglobin concentrations before donation were significantly higher, averaging 145.2 g L(-1) before donation and 114.9 g L(-1) immediately before surgery, whereas at the time of discharge, the haemoglobin concentration averaged 126.2 g L(-1) (P = 0.0001) in transfused patients. Data from this well-established ABD programme indicate less than 50% overall utilization. The activity in the programme increased until 1996 following which it dropped progressively. The low haemoglobin concentration after surgery is of concern and should foster a transfusion algorithm for these patients.

Blood Donors↗
PubMed2006

The contribution of platelets in the production of cryoprecipitates for use in a fibrin glue.

BACKGROUND AND OBJECTIVES: Cryoprecipitate has a wide application for use as a fibrin glue. In some situations, platelets are added to the preparation in order to enhance the fibrin glue. MATERIALS AND METHODS: Fresh plasma was collected by apheresis from the same donor to produce 250 ml of platelet-rich plasma (PRP) or platelet-poor plasma (PPP) (n = 12 each). Cryoprecipitate was then produced following the standards of the American Association of Blood Banks and resuspended to a total volume of 8 ml, from which aliquots were removed and assayed. Clot formation was measured using the thromboelastogram. RESULTS: The protein content of the two preparations was identical for PRP and PPP. Results for fibrinogen (PPP 475 +/- 220 mg; PRP 399 +/- 215 mg), Factor VIII (PPP 186 +/- 67 IU; PRP 175 +/- 70 IU) and von Willebrand Factor (PPP 260 +/- 104 IU; PRP 221 +/- 88 IU) were not significantly different. The concentration of platelet-derived growth factor was markedly higher (a 100-fold increase at 3778 +/- 1036 ng) when platelets were added to the plasma. There was a small, but not statistically significant, difference in the rate of clot formation (R = 2.3 for PPP and 3.8 for PRP) and clot strength (MA = 63.4 for PPP and 56.6 for PRP) between PPP and PRP cryoprecipitates when measured using the thromboelastogram. CONCLUSIONS: Platelets do not significantly increase the concentration of the usual constituents of cryoprecipitate; however, the levels of platelet-derived growth factor are markedly enhanced. Therefore, there are advantages for using PRP to enhance the growth of new tissue.

Blood Platelets↗
PubMed2006

Current perceptions of Canadian autologous blood donors.

BACKGROUND AND OBJECTIVES: We determined the perceptions and motivations of autologous donors to establish their regard for this process and the new blood system established in 1999 in Canada. MATERIALS AND METHODS: Patients were surveyed before and after orthopaedic, cardiac, urological or gynecological procedures. RESULTS: Patients (n = 100; 57 men and 43 women) ranged in age from 19 to 83 years. Most had finished high school, and 21 had a university degree. Eighty-four had undergone previous surgery and 27 a previous transfusion. Fifty-one had been blood donors and 17 had been autologous donors. Specialists suggested donation to 78 of the patients. Seventy-two participated because they knew that their blood would be there. Three had a mistrust of the blood provider. Sixty-six believed that there is still a risk of receiving contaminated blood. Sixty-nine thought any risk was > or = 1 in 100,000; however, 16 thought the risk was < 1 in 1000. Postsurgery, 83 were happy to have donated their blood and 77 would do it again. Many felt that it improved their outcome. Most felt an increased sense of safety. Eighty-three patients were confident that the Canadian blood system had improved, but 17 were unsure. CONCLUSIONS: Concern about the safety of the allogeneic blood supply still drives the wish to autodonate. The process gives patients a sense of control and security. A large proportion of people felt that the Canadian blood system had improved, as determined by this 2003 study.

Adult↗
PubMed2005

The development of an optimized autologous blood donation program.

BACKGROUND: Autologous blood (ABD) programs have been in place in Canada since the late 1980s. Activity is decreasing in many sites and utilization averages 50%. METHODS: In an effort to optimize our ABD program we introduced one time single donation red cell collection (Trima) with and without erythropoietin and compared the results to those with standard red cell collections. A pre-pilot study assessed feasibility. RESULTS: To date a total of 59 patients have entered the three arm Trima/epo pilot involving prostate surgery patients: their pre-surgical Hg 158 was compared to 108 in normal autologous control patients. By decreasing the standard pre-donation autologous requirement of three units of red cells to a single Trima collection and at $300 per autologous unit, this represents a cost savings of $36,000 in our 59 patients. When applied to the total autologous program at our hospital (450 per year), this extrapolates to a minimum savings of over $250,000 when using combined collection approaches. 32/59 patients in this pilot study have received only autologous blood, again reducing the number of allogeneic units that would have been required. The need for only a single autologous donation cuts nursing time by 2/3 and also saves laboratory money, since only a single unit is tested for infectious diseases. CONCLUSION: When applied to an autologous blood program, the use of the Trima machine combined with erythropoietin in appropriate cases, results in a decrease in the number of units collected and a higher pre-operative hemoglobin. This program should see application in other sites.

Blood Donors↗
PubMed2005

Development of a total quality system for transfusion medicine services in Ontario hospitals.

TOTAL QUALITY SYSTEM: The purpose of the project was to develop a total quality system in Transfusion Medicine which would serve as a model for development of a provincial transfusion quality system. Pilot studies were carried out in Ottawa and Hamilton/Niagara. Each region was provided with resources to create a Quality Team. The Quality Team was comprised of several individuals including a Quality Team Leader, and a number of Quality Assistants. The responsibilities of the Quality Team included: working with Transfusion Medicine Laboratories in area hospitals to achieve a total quality system, identification, standardization and implementation of 'best transfusion practices' throughout the regional hospitals, development and implementation of standard operating procedures (SOP) based on best practices, development and implementation of transfusion/administration guidelines, assessment of blood utilization, education, training, non-conformance (error) management, and surveillance. Liaison was also established with the co-coordinator for the Transfusion Co-coordinator's Project (ONTRAC), the education coordinator for the Sunnybrook Project, the Public Health Agency of Canada, Quality Management Practice-Laboratory System, the Ontario Hospital Association and Laboratory Licensing. In Ottawa these activities resulted in the development of:

Blood Banks↗
PubMed2004

The use of a bacteria detection system to evaluate bacterial contamination in PLT concentrates.

BACKGROUND: Random-donor PLTs (RDPs) are functional at 7 days. Nevertheless, since the mid-1980s, concern for bacterial contamination has caused the storage period to be reduced to 5 days. The ability of a bacteria detection system (BDS, Pall) to determine bacterial contamination and permit extension of the PLT shelf life to 7 days was assessed. STUDY DESIGN AND METHODS: Blood was collected into CP2D and leukoreduced RDPs were prepared. Upon arrival at the hospital, a 2- to 3-mL aliquot was removed from each RDP and introduced into the Pall BDS pouch with a sterile docking device. The pouch was incubated at 37 degrees C for 24 hours and then the oxygen content was measured to determine bacterial contamination. Additionally, the RDPs were pooled and an aliquot was removed for culture with standard manual techniques. CCIs were calculated 1 hour after infusion. RESULTS: A total of 12,062 individual RDPs were tested. The Pall BDS detected bacteria in 5 units. All of these were positive on repeat sampling. Propionibacterium acnes, coagulase-negative Staphylococcus, and Bacillus species were confirmed by manual technique in 3 units, one could not be identified, and one was negative. Aliquots from PLT pools were positive in 80 of 2201 pools when tested by manual methods. Of these, 79 were false-positives and 1 unit contained coagulase-negative Staphylococcus. The Pall BDS was easy to use and required less than 5 minutes for all manipulations. After 7 days of storage, the PLTs gave an average CCI of 16 x 10(11)+/- 3.39 x 10(11) 1 hour after transfusion (n = 9). CONCLUSIONS: The Pall BDS permits evaluation of RDPs for bacterial contamination. Culture-negative PLTs were successfully transfused in our institution up to and including 7 days after storage with good CCIs.

Bacillus↗
PubMed1991

Red blood cell alloimmunization complicating plasma transfusion.

Well-known adverse effects of plasma transfusion include viral transmission, allergic complications, and rare anaphylactic reactions. In making clinical decisions to transfuse plasma, a seldom-considered complication is that of red blood cell (RBC) alloimmunization. The authors report a patient in whom strong IgM and IgG anti-E and weak IgG anti-JKa RBC antibodies developed 15 days after infusion of two units of fresh-frozen plasma for volume expansion. These antibodies are potentially hemolytic. This case underscores the importance of considering risks of plasma infusion. Plasma should not be used casually, especially for indications for which alternate therapies, such as crystalloid and colloid solutions, are available.

Aged↗