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C T Smit Sibinga

Publications and source records attributed to C T Smit Sibinga.

At least 37 records · Page 2Linked to original sources
PubMed1991

Preparation and storage of "leukocyte-depleted single donor" platelet concentrate: a step forward in effective haemotherapy.

"Leukocyte-depleted" platelet concentrates (LD-SDPC) were prepared by cotton-wool and by polyester filtration of "leukocyte-poor" PC collected by the elutriation technique. The storage characteristics of LD-SDPC were comparable to those of the filtered pools of multiple donor platelet concentrates (LD-MDPC). However, LD-SDPC were less activated and less damaged than LD-MDPC over a 7-day storage period, as evidenced by beta-thromboglobin percent release and lactic dehydrogenase percent leakage in both products. LD-SDPC were prophylactically transfused to 12 thrombocytopenic patients; the mean bleeding time was shortened from 12 min 20 sec to 4 min 39 sec. Corrected count increment (CCI) was 22.8 at 1 hr and 14.1 at 24 hr compared to 15.5 and 10.0, respectively, with standard PCs.

Blood Component Transfusion↗
PubMed1991

In vitro evaluation of a high-efficiency leukocyte adherence filter.

In view of the currently available data, prevention of alloimmunization requires filters with higher efficiency to achieve a reduction in the number of leukocytes below 10 million per transfusion. Two versions (Pall PL-100 and PL-50) of the new generation leukocyte-depletion filters were studied. Single donor (SDPC)- and pooled multiple donor (MDPC) platelets were run in parallel. At a flow rate of 10 ml/min, the PL-100 filter was shown to effectively reduce the number of residual leukocytes to far below the critical immunogenic threshold of 10 million in all SDPC units and in 77% of MDPC units. Apheresis platelets appear not only to be better depleted than pooled multiple donor platelets, but also to have a better post-filtration platelet recovery (96% versus 84%). The efficiency of the smaller version of the filter (Pall-50) was higher than that of the Pall-100 filter for both single and pooled multiple donor platelet concentrates (PC). Leukocytes were absent in more than 92% of units in both types of concentrates. The maximal number of detected leukocytes was 2.2 million in a pool of 6 units. The outcome of filtration of 5-day-old pooled platelets was less favorable than filtration of 1- or 2-day-old pooled platelets, indicating that filtration soon after preparation is preferred to filtration after storage. Post-filtration platelet integrity, activation state, function, and morphology were all well preserved in both single and multiple PCs.

Blood Component Removal↗
PubMed1990

Alpha- and gamma-tocopherol in plasma, red blood cells, and platelets during plasma exchange.

The effect of a rapid reduction of plasma lipoproteins on the alpha- and gamma-tocopherol levels in plasma, erythrocytes, and platelets was studied. Sixteen successive plasma exchange procedures performed weekly in an adult with heterozygous familial hypercholesterolemia were evaluated. Plasma exchange was done by intermittent flow centrifugation, exchanging one plasma volume against a 4% human albumin solution. Plasma exchange reduced in plasma alpha-tocopherol from 41.5 +/- 8.9 to 23.6 +/- 4.8 mumol/L and gamma-tocopherol from 4.9 +/- 4.1 to 2.4 +/- 2.1 mumol/L, without changing their ratios to total lipids. It diminished alpha-tocopherol in platelets from 12.97 +/- 4.37 to 10.03 +/- 1.78 mumol/10(13) cells and gamma-tocopherol from 1.43 +/- 0.55 to 1.06 +/- 0.41 mumol/10(13) cells, but did not affect erythrocyte tocopherols. The total amount removed per procedure was 47.57 +/- 13.65 mumol for alpha-tocopherol and 4.70 +/- 3.59 mumol for gamma-tocopherol. Plasma exchange increased the number of erythrocytes from 3.67 +/- 0.10.10(12) to 4.05 +/- 0.13.10(12) cells/L, without affecting their volume. Platelet count did not change, but mean platelet volume decreased from 7.7 +/- 0.5 to 6.9 +/- 0.5 fl and platelet distribution width from 15.1 +/- 0.4 to 14.9 +/- 0.5. Thus, plasma exchange reduces plasma alpha- and gamma-tocopherol to the same extent as total lipids, and decreases these tocopherols in circulating platelets, along with a reduction in platelet size and, compared to the change in erythrocyte count, a fall of platelet number.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Platelets↗
PubMed1990

A simplified method for purification, concentration and freezing of bone marrow cells for autologous transplantation.

Autologous bone marrow (BM) transplantation is being increasingly applied in hematological and oncological patients. However, because of the need to purify and preserve BM requiring high technology, such treatments are virtually concentrated in the "developed" countries. This paper examines methods of BM purification and freezing that could make the technique potentially applicable in developing countries. Hemapheresis is routinely applied for BM purification in our Dutch Centre, where the buffy coats obtained from routine blood donations were utilised in experimental settings. Using DMSO as cryoprotectant, semi-purified white cells were frozen in liquid N2 (LN2), by mechanical freezer or snap-frozen at -55 degrees C. Different types of containers were compared including plastic tubes and ordinary blood bags. After thawing the results show that snap-freezing had a deleterious effect but the cell yields and viability were similar in LN2 or the mechanical freezer where the tubes and the bag were equally effective as containers (86% cell recovery with 90% viability). In the purification/concentration stage, reduction of the volume of the material by extra centrifugation, thus requiring less DMSO, produced better results--96% cell yield and 90% viability after thawing. This simplified method was applied in a general hospital in Sao Paulo where four oncology patients underwent BM collection. BM was purified and concentrated within a blood bank facility. Hydroxyethyl starch sedimentation and centrifugation of the material in plastic blood bags gave 80% BM cell harvest. After thawing from the mechanical freezer 1 x 10(8) BM cells/kg were available for reinfusion to patients. There was no immediate untoward reaction. Three of the patients showed signs of bone marrow regeneration by three weeks, but one patient died 16 days after transplantation, of septicemia. We conclude that certain high-technology procedures for ABMT can be adapted for existing facilities in developing countries.

Bone Marrow Transplantation↗
PubMed1989

Bleeding prophylaxis in autologous bone marrow transplantation for solid tumors. Comparison of cryopreserved autologous and fresh allogeneic single-donor platelets.

Bleeding prophylaxis with cryopreserved autologous thrombocytes was evaluated in 43 patients treated with high-dose chemotherapy and autologous bone marrow transplantation. Platelet transfusions were given prophylactically. Nineteen patients received only autologous, 10 only fresh allogeneic single-donor, and 14 both types of transfusions. The effects of 104 autologous versus 93 allogeneic thrombocyte transfusions were compared. The increment at 1 h was for allogeneic platelets twice that for autologous platelets (30.6 versus 15.2 x 10(9)/l), but the interval between transfusions in days (2.3) was the same. Twelve patients received alternating autologous platelet transfusion after washing out the cryoprotectant dimethyl sulfoxide (18 transfusions) and non-washed autologous platelets (24 transfusions). Platelet increments, corrected increments, and predicted recovery were not influenced by omitting the washing procedure, and no side effects of dimethyl sulfoxide occurred.

Adult↗
PubMed1989

Informing blood donors about AIDS and risk factors: reactions to information provided in a regional blood bank in the Netherlands.

To safeguard blood transfusion therapy, anti-HIV testing has been standard in routine blood bank practice in the Netherlands since mid-1985. Despite the availability of serological testing for HIV infection, donor deferral remains of prime importance because of the period between HIV-infection and development of antibodies (the 'window phase'). Therefore blood and plasma donors are informed about AIDS and risk factors. Reactions of donors to such information were investigated in a regional blood bank in the Netherlands (1985-1987). Although there seems to be a good understanding of the necessity of reading information about AIDS, personal motives (not belonging to a risk group, having read information before, etc.) resulted in insufficient attention to the written information (a circular letter) by more than one third of respondents. We recommend that information on risk factors is given by a personal approach (i.e. interview) and by emphasizing the personal responsibility of donors for the safety of the blood supply used in blood transfusion therapy.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Double cryoprecipitated factor VIII concentrate from heparinised plasma and its heat treatment.

In an attempt to implement the small pool concept in Factor VIII purification, cryoprecipitate derived from heparinised plasma was reprecipitated in the cold providing a factor VIII concentrate for freeze drying and heat treatment. There was considerable purification; only 1% of the original plasma proteins was left in the final product. Factor VIII:C concentration was about 19 IU/ml. Factor VIII related antigen (RAg) appeared heterogeneous, with a broad base and asymmetry on crossed immunoelectrophoresis. Fibrinogen content was 15 g/l. In contrast to high-purity commercial concentrates, fibronectin was considerably concentrated. Immunoglobulin contents were similar to a high-purity commercial product. The amount of other plasma proteins was very small, varying from less than 0.2% for C3 complement to 2.3% ceruloplasmin. In some respects the preparation may be considered as an intermediate-purity Factor VIII concentrate. Following addition of 2% sucrose before freeze drying, Factor VIII, total protein and fibrinogen remain virtually stable (less than 15% loss) during heating of the material to 60, 64 or 68 degrees C for 24 to 72 h without changes of protein spectrum following heating. The heated product when stored at 4 degrees C remains stable for at least 3 months. In two severe haemophiliacs receiving this heat treated product, in vivo Factor VIII recovery was 100% with a mean half life of 10.2 h.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Small-pool high-yield factor VIII production.

Hemophilia care depends on several factors for the production of purified FVIII: plasma procurement, plasma logistics, production method, and efficacy. The latter two are restrictive factors, both for the supply and the safety of FVIII preparations. Conventional production methodology unavoidably recovers only 10 to 20% of usable protein, therefore requiring large pools of source plasma. Related to pool size is the transmission of diseases, which poses unnecessary risks for patients. The development of new technologies to better recover FVIII allows reduction of the pool size: crush-thaw, controlled pore-glass chromatography, and heparin double-cold precipitation techniques. This review will reflect on current production methods, pool size concept, small-pool approaches in FVIII production, and future developments.

Blood Component Removal↗
PubMed1984

Heparin small pool high yield purified factor VIII: in vivo recovery and half-life of routinely produced freeze-dried concentrate.

New approaches and techniques for improving source material collection and Factor VIII production at Blood Bank level have been reported recently. Heparin has been shown to be of importance in increasing yields and stability of FVIII in the purification and concentration process. Work has been done to develop on a routine scale the heparin double cold precipitation technique for the production of a freeze-dried high yield purified FVIII concentrate. The product has been tested clinically in 4 severe hemophilia A patients for recovery, half-life and acute side-effects, using two dosages over 8 infusions. There was no significant difference between the two dosages. Mean recovery 99.1% and mean half-life 8 hr, ranging from 6.5 to 10.3 hr. No side-effects justify further exploration of the potential of heparin for high yield purified FVIII production.

Adult↗
PubMed1984

Comparison of apheresis and other methods for separation and purification of hemopoietic stem cells: initial experience with a blood buffy coat model for the use of autologous bone marrow transplantation.

With an increasing number of bone marrow transplantations (BMT) being contemplated in leukemia and cancer patients, it is prudent for blood banks to develop a suitable program within their resources for harvesting, purifying and freezing bone marrow stem cells. In order to do this, initially a prototype has been developed involving buffy coat model (BC) using normal donor blood. Centrifugation, sedimentation and machine apheresis methods were separately evaluated leading to a combined and sequential handling procedure. Blood was passed through a cell separator resulting collection of BC with 90% reduction of the volume showing 80% recovery of total leucocytes and 87% yield of mononuclear cells. Following centrifugation the cells with DMSO were frozen in a controlled freezing system and stored in liquid nitrogen. After thawing 94% cells were recovered with 93% viability. The initial experience gained in the model system could be incorporated in autologous BMT program in patients but requires modifications for improved results; the latter will be described separately.

Blood Cells↗