MicroRNA (miRNA) expression profiling of peripheral blood samples in multiple myeloma patients using microarray

MicroRNAs (miRNAs) are mostly located at cancer-associated genomic regions or in fragile sites, suggesting their important role in the pathogenesis of human cancers. Multiple myeloma (MM) is a cancer of plasma cells, the third most common cancer of the blood after lymphoma and leukaemia. There are several published reports on miRNAs in MM, however most used bone marrow rather than peripheral blood samples. The aim of this study is to characterise miRNA expression in normal and MM patients using peripheral blood samples as it is less invasive and is readily available from patients. Blood samples from 35 MM patients were analysed using the microarray method. We identified up-regulation of 36 miRNAs (57%) and down-regulation of 27 miRNAs (43%). We also identified the CCND2, HMGA2 and IGF1R genes were among the highly predictive target genes (P(CT) > 0.80) for most of the deregulated miRNAs. These genes are known to play important roles in MM as well as other cancers. Five miRNAs (let-7c, miR-16, miR- 449, miR-181a and miR-181b) were found to exhibit similar expression patterns (p < 0.05) in peripheral blood when compared to data obtained by using bone marrow aspirates from MM patients in other studies. In conclusion, our study has demonstrated that miRNAs are also present and differentially expressed in the peripheral blood of MM patients compared to controls and may potentially serve as candidate tumour biomarkers in MM. In particular, let-7c and miR-16 have been shown to be significantly expressed in the bone marrow.

External quality assurance in Malaysia.

An activity supportive of the MOH QA Programme, the National EQAS for clinical chemistry monitors for analytical performance in core routine biochemical testing by the pathology laboratories, with unsatisfactory performance scores serving to alert against deficiencies or problems and the scores in subsequent challenges providing the feedback of effectiveness of remedial actions taken. While unacceptable individual analyte performance score (variance index score, VIS) indicated problems in instruments, reagent and calibrators, or the use of inherently poorer methods, repeated occurrence of unsatisfactory OMRVIS was traceable to generally poor laboratory management of usually inadequately-equipment small laboratories. The outcome has been one of slow but gradual improvement in the overall performance of participating laboratories, with a move towards methods upgrading and standardization to achieve greater concordance of results. Presently, the programme is limited to 61 government and 4 private hospital laboratories in the country for 12 commonly assayed clinical biochemistry analytes. It is hoped that the NEQAS could be extended to the other private laboratories and that of academic institutions. However, this is dependent to a large extent on the manpower and financial support obtainable by the organizing body of the programme in the future. Belk and Sunderman, 1947 demonstrated that laboratories participating in an quality assessment scheme could rapidly and dramatically improve their analytical performance. In some countries, participation has become mandatory, and acceptable performance is a requirement in laboratory accreditation. The need and value of the NEQAP is, therefore, evident. While there may be limitations in the national programme. efforts are being made at improving the programme within the means and resources of the organising body. The goals of the NEQAP are not just to monitor performance but also to educate. On this, matters related to and supportive of these goals have also been pursued. The annual workshop/forum on quality controls had allowed exchange of information between representatives of participating laboratories and the organising body. Recently in the 1997 MOH Quality Improvement evaluation, Quality Control has been evaluated together with the other 17 such activities. The study on knowledge, attitude and practice has provided the necessary feedback and will be used for future planning in making efforts at increasing the effectiveness and benefits of the all QC activities including this NEQAP for clinical chemistry. In addition, there is a need to look into areas such as selection of methods and test systems, and improvement of continuing education, training as well as research in quality improvement as suggested by the Quality Improvement evaluation.

Inborn errors of metabolic diseases in Malaysia: a preliminary report of maple syrup urine diseases for 1993.

The Malaysian level of health care has greatly improved so that many of the infectious diseases are now under control. However, perinatal death or death due to unknown childhood diseases remains high (10.3%) being second on the list of causes of death amongst Malaysians. Could inborn metabolic diseases be the main cause of death among these children? Recently, with our success in the development of confirmatory techniques for amino acid disorders using high performance liquid chromatography (HPLC), we have examined 404 samples received from all over the country in 1993. Each specimen with abnormal findings from screening tests by one-dimensional thin layer chromatography was confirmed using HPLC. 41% had generalized aminoacidurias and 4.2% had maple syrup urine disease (MSUD). Patients were aged between 11 days to 6 years. Most of them were Malay males and presented with a history suggestive of MSUD. With this preliminary finding, further studies will be carried out in order to have an investigation and management protocol for the diseases and more importantly to formulate a strategy of screening for the country.