PubMed Health⌕ Search

Biomedical subjects

J M Abdullah

Publications and source records attributed to J M Abdullah.

11 recordsLinked to original sources

Computed tomography perfusion of ischaemic stroke patients in a rural Malaysian tertiary referral centre.

INTRODUCTION: Computed tomography (CT) perfusion is a new method to diagnose ischaemic stroke especially in developing countries. It identifies the area and is useful to predict the size of final infarction. The aim of this study was to assess cerebral ischaemia with CT perfusion (CTP) among patients with acute ischaemic stroke in Hospital Universiti Sains Malaysia, a tertiary referral centre in a rural setting. METHODS: 42 consecutive unenhanced CT and CTP examinations of the brain in adult patients were evaluated prospectively. Unenhanced CT images were divided into normal, suspicious or frank infarction. CTP images was classified as normal or ischaemic. Subgroup analysis was carried out with a limit of six hours from time of ictus. RESULTS: Out of 42 patients, 20 had frank infarction on unenhanced CT, 15 had suspicious CT studies, while seven were normal. There was no significant association of demographical, clinical and radiological parameters to CTP in the whole group among acute stroke patients without frank infarction. Among the subgroup of patients without frank infarction, there was no significant association between unenhanced CT and CTP in patients who were studied less than six hours after stroke (p-value is 0.063) as well as those after six hours (p-value is 0.317). The prevalence of a normal unenhanced CT and positive CTP for ischaemia was 22.7 percent (95 percent confidence interval 7.8, 45.4). CONCLUSION: CTP may be a useful imaging tool for determining cerebral infarction in a rural-based community population, especially in cases where the unenhanced CT is normal. Thrombolysis is a therapeutic option, even when the history of onset of stroke is unclear.

Acute Disease↗

Third ventricular cavernous angioma.

Third ventricular cavernous angiomas are rare vascular malformations of the brain. We report an eight-year old boy with a rare third ventricular cavernous angioma that hemorrhaged presenting with symptoms of acute hydrocephalus. Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) showed a heterogenous ill-defined, solid and cystic intraventricular mass in the third ventricle which was mildly enhanced with contrast and there was associated hydrocephalus. The mass was removed with success and follow up after two years revealed no neurological abnormalities.

Central Nervous System Neoplasms↗

Characteristics and clinical predictors of minor head injury in children presenting to two Malaysian accident and emergency departments.

INTRODUCTION: Paediatric minor head injuries (MHI) are just as common in both bigger and smaller towns in Malaysia. Urban-based MHI are due more to motor vehicular injuries compared to rural-based MHI which are mainly due to non-motor vehicular injuries. The main objectives of this study were to compare incidence of admitted patients to accident and emergency departments of hospitals in two different settings in Malaysia, namely: Ipoh (urban-based) and Kota Bharu (rural-based); and to correlate to demographical characteristics, types of accident, clinical signs and symptoms, radiological and computed tomography (CT) findings, management; and finally, to determine clinical predictors of intracranial injury in MHI. METHODS: A cross-sectional study of 153 paediatric patients aged 2-18 years who were admitted to the Ipoh Hospital, Perak and 112 patients of the same age group admitted to Hospital Universiti Sains Malaysia, Kelantan were included in this study. The study period was between 1 January 1998 and 31 December 2001. Data collection was done prospectively. Chi-square and independent t-tests were applied to compare characteristics of patients admitted to these two hospitals. Backward stepwise multiple logistic regression was applied to determine clinical predictors of intracranial injury. RESULTS: There were significant differences of age, race, types of accidents, clinical signs and symptoms, Glasgow coma scale (GCS), skull fracture and CT findings between two hospitals. Significant clinical predictors were headache (OR 20.8, 95 percent CI 3.9-25.2, p-value is less than 0.001), unequal pupils (OR 8.4, 95 percent CI 4.3-17.9, p-value is equal to 0.0413) and GCS score of 13 (OR =3.8, 95 percent CI 1.9-6.8, p-value is equal to 0.005). Skull fractures and intracranial injuries were more common in Kota Bharu due to children riding motorcycles without helmets than in Ipoh (p-value is less than 0.001). CONCLUSION: In the rural Malaysian community, both the police and physicians must be alerted to the fact that unhelmeted children riding motorcycles are more likely to sustain morbidity than those in urban areas. More aggressive traffic policing of the village roads should be done by the relevant authorities.

Accidents↗

Malignant glioma: the involvement of loss of allelic heterozygosity and PTEN mutations in a group of Malay patients.

Frequent loss of heterozygosity (LOH) and mutations of the tumor suppressor gene PTEN (phosphatase and tensin homologue deleted from chromosome 10) have been found in sporadic gliomas. The most documented regions of allelic losses include 9p21, 10q23-25 and 17p1 3 whereas PTEN aberrations are preferentially found in glioblastoma multiformes. This research aimed to detect the incidence of allelic losses on chromosomes 10q, 9p, 17p and 13q and mutations on exons 5, 6 and 8 of PTEN in malignant gliomas. Malignant glioma specimens obtained were classified histopathologically according to the WHO criteria. Each tumor was then subjected to polymerase chain reaction (PCR)-LOH analysis using microsatellite markers and single-stranded conformational polymorphism (SSCP) analysis. Twelve of 23 (52%) malignant glioma cases showed allelic losses whereas 7 of 23 (30%) samples showed aberrant band patterns and mutations of PTEN. Four of these cases showed LOH in 10q23 and mutations of PTEN. The data on LOH indicated the involvement of different genes in the genesis of glioma whereas mutations of PTEN indicated the role of PTEN tumor suppressor gene in the progression of glioma in Malay population.

Adolescent↗

Malignant rhabdoid tumour of the brain.

Rhabdoid tumour is a rare childhood tumour with poor prognosis. We report a 13-month-old Malay girl suffering from this tumour that was located at the left fronto-temporo-parietal region of the brain. Computed tomography showed a large irregular enhancing mass that caused obstructive hydrocephalus. The tumour did not reduce in size after three operations and finally the patient succumbed to the disease four months after diagnosis.

Brain Neoplasms↗

Presence of allelic loss and PTEN mutations in malignant gliomas from Malay patients.

Loss of heterozygosity (LOH) on several loci and mutations on PTEN tumor suppressor gene (10q23.3) occur frequently in sporadic gliomas. We have performed polymerase chain reaction (PCR)-LOH analysis using microsatellite markers and single-stranded conformational polymorphism (SSCP) analysis to determine the incidence of allelic losses on chromosome 10q, 9p, 17p and 13q and mutations of exons 5, 6 and 8 of the PTEN gene in malignant gliomas. Twelve of 23 (52.2%) malignant glioma cases showed allelic losses whereas 7 of 23, (30.4%) samples showed aberrant band patterns and mutations of the PTEN gene. Four of these cases showed LOH on 10q23 and mutations of the PTEN gene. The data on LOH indicated the involvement of different genes in gliomagenesis whereas mutations of the PTEN gene indicated the role of PTEN tumor suppressor gene in the progression of glioma in Malay population.

Brain Neoplasms↗

Malignant paraganglioma of frontoethmoidal region.

Nonchromaffin paragangliomas are unusual tumours arising from widely distributed paraganglionic tissues probably of neural crest origin. In the head and neck region they are usually seen as carotid body or jugulotympanic tumours. Other rarely reported sites in the head and neck region are the orbit, nose and larynx. This report deals with a case of sinonasal paraganglioma which was initially treated with surgery and radiotherapy. Twenty two years later the tumour recurred and showed a rapid growth due to malignant transformation which we believe is late effect of radiotherapy. The clinical features, histopathology and role of radiotherapy in sinonasal paragangliomas together with a review of the medical literature have been discussed.

Adult↗

Teratocarcinosarcoma of the nasal cavity and ethmoid.

Sinonasal teratocarcinosarcoma is very unusual malignant neoplasm histologically consisting of an epithelial element and one or more mesenchymal components. This is a report of teratocarcinosarcoma, in a 74-year-old male, involving the right nasal cavity and ethmoids with intracranial extension. The tumour was totally resected via the craniofacial approach and the patient was given post-operative chemotherapy. Extensive tumour necrosis, rapid growth and local destruction are the prominent features of this tumour. The clinical presentation, pathological features and clinical course of this rare malignancy are discussed with a review of the literature.

Aged↗

FLRF, a novel evolutionarily conserved RING finger gene, is differentially expressed in mouse fetal and adult hematopoietic stem cells and progenitors.

Through differential screening of mouse hematopoietic stem cell (HSC) and progenitor subtracted cDNA libraries we have identified a HSC-specific transcript that represents a novel RING finger gene, named FLRF (fetal liver ring finger). FLRF represent a novel evolutionarily highly conserved RING finger gene, present in Drosophila, zebrafish, Xenopus, mouse, and humans. Full-length cDNA clones for mouse and human gene encode an identical protein of 317 amino acids with a C3HC4 RING finger domain at the amino terminus. During embryonic hematopoiesis FLRF is abundantly transcribed in mouse fetal liver HSC (Sca-1+c-kit+AA4.1+Lin- cells), but is not expressed in progenitors (AA4.1-). In adult mice FLRF is not transcribed in a highly enriched population of bone marrow HSC (Rh-123lowSca-1+c-kit+Lin- cells). Its expression is upregulated in a more heterogeneous population of bone marrow HSC (Lin-Sca-1+ cells), downregulated as they differentiate into progenitors (Lin-Sca-1- cells), and upregulated as progenitors differentiate into mature lymphoid and myeloid cell types. The human FLRF gene that spans a region of at least 12 kb and consists of eight exons was localized to chromosome 12q13, a region with frequent chromosome aberrations associated with multiple cases of acute myeloid leukemia and non-Hodgkin's lymphoma. The analysis of the genomic sequence upstream of the first exon in the mouse and human FLRF gene has revealed that both putative promoters contain multiple putative binding sites for several hematopoietic (GATA-1, GATA-2, GATA-3, Ikaros, SCL/Tal-1, AML1, MZF-1, and Lmo2) and other transcription factors, suggesting that mouse and human FLRF expression could be regulated in a developmental and cell-specific manner during hematopoiesis. Evolutionary conservation and differential expression in fetal and adult HSC and progenitors suggest that the FLRF gene could play an important role in HSC/progenitor cell lineage commitment and differentiation and could be involved in the etiology of hematological malignancies.

Age Factors↗

Cloning and characterization of Hepp, a novel gene expressed preferentially in hematopoietic progenitors and mature blood cells.

Through differential screening of mouse hematopoietic stem cell (HSC) and progenitor-subtracted cDNA libraries we have identified a progenitor cell-specific transcript that represents a novel gene, named Hepp (hematopoietic progenitor protein). The mouse Hepp gene encodes a protein of 237 amino acids with no detectable known functional domains or motifs. Lack of invertebrate orthologs and a high degree of evolutionary conservation of the peptide sequence in vertebrate species (zebrafish, mouse, human) suggest that the Hepp gene could have conserved although as yet unknown function in vertebrates. Mouse Hepp shows a restricted expression pattern in adult tissues and is transcribed at a very low level in heart, lung, spleen, and thymus and at a higher level in muscle. During embryonic hematopoiesis Hepp is not expressed in mouse fetal liver HSC (Sca-1(+)c-kit(+)AA4.1(+)Lin(-) cells), but is abundantly transcribed in the population of hematopoietic progenitors (AA4.1(-) cells). Similarly, during adult hematopoiesis Hepp is not transcribed in the highly enriched population of bone marrow HSC (Rh-123(low)Sca-1(+)c-kit(+)Lin(-) cells), but its expression is upregulated as a greater heterogeneous population of bone marrow HSC (Lin(-)Sca-1(+) cells) differentiates into progenitors (Lin(-)Sca-1(-) cells) and more mature lymphoid and myeloid cell types. A restricted pattern of expression in adult tissues and preferential expression in both fetal and adult hematopoietic progenitors and mature blood cells suggest that Hepp could be involved in molecular regulation of HSC and progenitor cell lineage commitment and differentiation.

Animals↗