OAR@UM Collection:

The use of platelet additive solution for the preparation of pooled platelets

Sun, 01 Jan 2006 00:00:00 GMT

Title: The use of platelet additive solution for the preparation of pooled platelets Abstract: By the time my study was validated by the quality assurance manager and it began to be used as a routine procedure, there were major problems especially during the 5 day storage of pooled platelets. The use of Composol as a platelet additive solution is to stabilize the pH of the final product during the 5 day of storage. This study was divided into 4 parts. In the 1st. part of this study, 20 pooled platelets were prepared. Initially 300ml. Composol were used for 5 buffy coats, but by trial and error it was determined that 100ml. Composol was the best amount to be used so that the final platelet count would be within the Council of Europe regulations. Therefore the remaining 3 parts of the study were analyzed by using 100ml. Composol for 5 buffy coats, each buffy coat having approximately the median weight within the range, that is 116g. In the 2nd part of the study, 38 pooled platelets were prepared and these were analysed for pH, pC02, and p02.from Dayl to day 7 of storage. The pH range should be between 6.4 to 7.4 according to the 'Guide to the preparation, use and quality assurance of blood c01nponents' regulations. In the 3rd. part of the study, 101 pooled platelets were prepared during the study period to analyze the Corrected Count Increment on patients after transfusion. Since only 43 pooled platelets were transfused between 1st. And 2nd. Day of preparation only these were calculated for the Corrected Count Increment. In the 4th. Part of this study, two types of comparisons were made with a previous study done by Agius in 2003. Agius had prepared pooled platelets by using plasma instead of Composol PS as an additive solution for platelets and therefore one can compare what are the advantages and disadvantages between the two systems were compared. The first comparison was done for the storage lesion by comparing pH, pC02, and p02 and the second comparison was carried out to determine the different values obtained when analyzing the Corrected Count Increments when using pooled platelets prepared with different products as an additive solution for platelets. Description: B.SC.(HONS)APPLIED BIOMED.SCI.

Low protein Z levels and the risk of thrombophilia

Sun, 01 Jan 2006 00:00:00 GMT

Title: Low protein Z levels and the risk of thrombophilia Abstract: Protein Z (PZ) is a vitamin K-dependent plasma glycoprotein whose physiological function is still not clearly defined. Studies suggest that protein Z inhibits the procoagulant activity of activated factor X (Xa), in the presence of Ca2+, phospholipids and another plasma protein, protein Z-dependent protease inhibitor (ZPI). This will result in down-regulation of coagulation. Low PZ levels were found to enhance the risk of arterial thrombosis, but not venous thrombosis which, could possibly lead to stroke and acute coronary syndromes. Controversial results were obtained regarding PZ levels and ischaemic stroke. A high frequency PZ deficiency was also found among women with one early primary foetal loss, predominantly between the 10th and 19th week of pregnancy. In this study 153 healthy individuals were tested for PZ antigen levels, using Asserachrom PZ ELISA kit from Diagnostica Stago, in order to determine a reference range for the Maltese population and the frequency of PZ deficiency in these individuals. PZ levels were also investigated in a group of 52 patients that were divided as follows: Group I: 32 patients who suffered recurrent foetal loss; Group 2: 13 patients who suffered a thromboembolic event; Group 3: 7 patients who suffered an ischaemic stroke. We compared the mean PZ level in each patient group with the mean PZ level obtained in the normal group. We also compared the frequency of PZ deficiency occuring in each patient group with that of the normal group. Results showed compliance with those obtained by other studies. We found that PZ levels have a wide total range in the Maltese population. Statistical analysis showed that there is no relationship between PZ levels and age or gender. Results of patients also concorded with those of other research groups. Statistical comparisons of the mean PZ level in each patient group with that of the normal group indicated that there is no significance difference among the means. Moreover, the frequency of PZ deficiency found in the patients was similar to that found in normal individuals. Thus we concluded that there is no relationship between PZ levels and the risk of recurrent foetal loss, thromboembolic event or ischaemic stroke. We are aware of our limitations and thus further studies are definitely required to clarify the role of PZ in such thrombophilic states. Description: B.SC.(HONS)MED.LAB.SCI.

The Application of Fluorescence in situ Hybridization (FISH) in Haematological Malignancies

Sun, 01 Jan 2006 00:00:00 GMT

Title: The Application of Fluorescence in situ Hybridization (FISH) in Haematological Malignancies Abstract: The Philadelphia chromosome involves the reciprocal translocation between the long arms of chromosome 9 (9q34) and chromosome 22 (22q11.2) involving the ABL and BCR gene. This leads to the formation of two fusion genes, the BCR/ ABL fusion gene on derivative chromosome 22 (the Philadelphia chromosome) and the ABL/BCR on derivative chromosome 9. The Philadelphia chromosome is detected in 95% of cases with chronic myeloid leukemia, in 2-5% of cases in childhood ALL, 25% of cases in adult ALL and in 3% of acute myeloid leukemia. The Philadelphia chromosome is detected by cytogenetic and molecular techniques. Fluorescence in situ hybridization (FISH) is a molecular cytogenetic technique that allows the hybridization of chromosomal abnormalities by the hybridization of a fluorescent labelled DNA probe to target DNA. The main aim behind this dissertation was to optimize and apply FISH technique using the LSI BCR-ABL double fusion probe for the detection of the Philadelphia chromosome in 41 cases of haematological malignancies. The Philadelphia chromosome was detected in fifteen out of fifteen cases of CML cases and in one out of thirteen cases of acute lymphoblastic leukemia There was no evidence of Philadelphia chromosome by FISH in a117 cases of acute myeloid leukemia and in all 6 suspected CML cases that showed overlapping features with other myeloproliferative disorders. In conclusion, this study was successful in optimizing a FISH method that can be used routinely as a diagnostic and a prognostic tool for the detection of the Philadelphia chromosome in haematological malignancies. Moreover, the application of FISH was useful in complementing conventional cytogenetics to detect the Philadelphia chromosome in cases were no dividing cells were present, in cases with poor chromosome morphology, and in cases with complex rearrangements. Description: B.SC.(HONS)MED.LAB.SCI.

The efficacy of donor arm disinfection techniques in reducing platelet contamination.

Sun, 01 Jan 2006 00:00:00 GMT

Title: The efficacy of donor arm disinfection techniques in reducing platelet contamination. Abstract: Bacterial contamination of blood and its components can be mostly attributed to inadequate skin venipuncture site disinfection, defective blood bags and associated equipment together with inappropriate storage or processing. Since platelets are stored at room temperature (21-23°C), they are most likely to be contaminated since bacterial growth is enhanced at this temperature. The main aim of this study was to validate the current method used to disinfect the donor's arm using 70% Isopropyl Alcohol (IPA) carried out at the four different blood donation sites:- The National Blood Transfusion Centre (NBTC), Gozo General Hospital (GGH), Soverign Military Order of Malta (SMOM) and Mobile unit. This study found a statistically significant difference between bacterial counts present on the non-donation arm and those present on the donation arm following disinfection (p < 0.01). There was no statistically significant difference between gender and bacterial counts (p = 0.918). Negative correlation was present between bacterial counts and donor age (p = 0.874). Disinfection methods using 70% IPA, and 70% IPA followed by the application of decolorised Iodine Tincture were compared in relation to bacterial counts present on the donation arm following disinfection. Both disinfection methods yielded optimal results namely zero bacterial counts at the venipuncture site following disinfection. This study concludes that the skin disinfection technique currently in use at the four blood donation sites using 70% IPA is effective enough in reducing bacterial contamination of blood and its components. Description: B.SC.(HONS)MED.LAB.SCI.