At least three major antigenic dengue 2 virus proteins were recognized by pooled dengue fever patients' sera in infected Aedes albopictus (C6/36) mosquito cells. Dengue virus envelope (E), premembrane (PrM) and non-structural protein 1 (NS 1) dimer were detected beginning on day 3 postinfection in both the cell membrane and cytosolic fractions. Using the patients' sera, the presence of antigenic intermediate core protein (C)-PrM and NS1-non-structural protein 2a (NS2a) in the cytoplasmic fraction of dengue 2 virus infected cells was revealed. The presence of a approximately 92 and approximately 84 kDa NS 1 dimer in the membrane (NS 1m) and cytosolic (NS 1c) fractions of C6/36 cells, respectively, was also recognized. Using individual patient's serum, it was further confirmed that all patients' sera contained antibodies that specifically recognized E, NS 1 and PrM present in the dengue 2 virus-infected cell membrane fractions, suggesting that these glycosylated virus proteins were the main antigenic proteins recognized in vivo. Detection of dengue 2 virus C antibody in some patients further suggested that C could be antigenic if presented in vivo.
Dengue continues to be a major health threat to Malaysia a century after its first reported outbreak in 1902. Examination of the available outbreak data suggested that a major DF/DHF outbreak occurred in Malaysia in a cyclical pattern of approximately every 8 years. All four dengue virus serotypes are found co-circulating in Malaysia, but after the first and only major outbreak involving DEN-4 in 1960's, only DEN-1, DEN-2 and DEN-3 were associated with DF/DHF outbreaks. It is argued that perhaps the spread of the later dengue virus serotypes followed the pattern of spread of the mosquito vector Aedes aegypti, whereas the former was associated with Aedes albopictus, the outdoor and rural area dwelling mosquito. Estimating from the trend and pattern of dengue and the associated dengue virus serotypes, unless there is a major breakthrough in dengue vaccine development, it is likely that dengue outbreaks will continue to occur in Malaysia throughout the 21st century.
Filariasis, a parasitic infection endemic in parts of India, Myanmar, islands of the South Pacific, West and East Africa and Saudi Arabia can be diagnosed from various types of cytopathological specimens. This case documents the detection of filarial infection from hydrocele fluid cytology in a 30-year-old Myanmar migrant worker in Malaysia.
A 42-year-old Chinese woman presented with transient confusional state and memory loss due to acute water intoxicational hyponatremia complicating colonic irrigation (enemas) used as an alternative medicine to promote health. Although there is no evidence that such "antiautointoxication" technique conveys true benefit in any condition, this form of "quackery" may actually cause harm, such as water intoxication as in this case.
The capillary electrophoresis (CE) is a new system that utilizes the principle of electrokinetic separation of molecules in eight electrolyte buffer-filled silica capillaries. In this study, we established the normal ranges of haemoglobin A2 (HbA2) and haemoglobin F (HbF) levels for normal individuals using this system and also the HbA2 level in beta thalassaemia and haemoglobin E (HbE) individuals.
Leptospirosis is an emerging infectious disease. The differential diagnosis of leptospirosis is difficult due to the varied and often "flu like" symptoms which may result in a missed or delayed diagnosis. Leptospira is the aetiological agent of leptospirosis, a bacterial zoonosis with worldwide distribution. There are over 230 known serovars in the genus Leptospira. The true prevalence of leptospirosis in Malaysia is unknown or underestimated. Our goal was to determine the prevalence for Leptospira infection in rodents in a selected area in Beguk Dam Labis, Segamat, Johor. A study was carried out on 69 serum samples of trapped wild rodents. DNA was extracted from the sera using Leptospira PCR kit (Shanghai ZJ Bio-Tech Co., Ltd). Of 69 rodent serum samples tested by PCR, 9 (13%) showed positive results. In this study we found that (13%) of wild rodents caught in Beguk Dam Labis were infected by Leptospira.
Threatened miscarriage is a common complication of pregnancy. Despite initial viability confirmation by ultrasound scan, some of these patients had further spontaneous abortion. A highly sensitive and specific biomarker would be useful to determine the outcome of pregnancy and to prevent emotional impact to these women. A prospective 14-month cohort study was conducted in the Obstetrics and Gynaecology Department of Universiti Kebangsaan Malaysia Medical Centre to determine whether low serum levels of pregnancy-associated plasma protein A (PAPP-A) measured in early pregnancy can predict the outcome of threatened abortion. 42 pregnant women between 6 to 22 weeks of gestation with threatened abortion and 40 controls were enrolled. Serum samples were collected at presentation and PAPP-A was assayed by electrochemiluminescent immunoassay technique. Pregnancies were followed-up until 22 weeks of gestations and the outcome documented. Nine patients (11%) developed spontaneous abortion and 73 patients (89%) had successful pregnancy. The median PAPP-A level was significantly lower in patients with spontaneous abortion compared to those who had successful pregnancies in the threatened abortion group: 0.78 MoM (0.41-1.00 MoM) vs 1.00 MoM (1.00-2.0 MoM) respectively (p < 0.05). The best sensitivity of 44% and specificity of 93% were obtained at the cut of value of 0.66 MoM (95% CI, 0.561-0.773). In conclusion, low PAPP-A value in threatened abortion women is associated with pregnancy failure, although the use of PAPP-A as a one-time single marker has limited value.
Forensic entomology applies knowledge about insects associated with decedent in crime scene investigation. It is possible to calculate a minimum postmortem interval (PMI) by determining the age and species of the oldest blow fly larvae feeding on decedent. This study was conducted in Malaysia to identify maggot specimens collected during crime scene investigations. The usefulness of the molecular and morphological approach in species identifications was evaluated in 10 morphologically identified blow fly larvae sampled from 10 different crime scenes in Malaysia. The molecular identification method involved the sequencing of a total length of 2.2 kilo base pairs encompassing the 'barcode' fragments of the mitochondrial cytochrome oxidase I (COI), cytochrome oxidase II (COII) and t-RNA leucine genes. Phylogenetic analyses confirmed the presence of Chrysomya megacephala, Chrysomya rufifacies and Chrysomya nigripes. In addition, one unidentified blow fly species was found based on phylogenetic tree analysis.
The aim of this study was to examine cells (split-sample) that were retained on sampling devices used to collect conventional Pap smears (primary smears) in order to evaluate specimen adequacy and cytological diagnosis of scrapings that are routinely discarded.
Microgravity, hypergravity, vibration, ionizing radiation and temperature fluctuations are major factors of outer space flight affecting human organs and tissues. There are several reports on the effect of space flight on different human cell types of mesenchymal origin while information regarding changes to vascular endothelial cells is scarce. Ultrastructural and cytophysiological features of macrovascular endothelial cells in outer space flight and their persistence during subsequent culturing were demonstrated in the present investigation. At the end of the space flight, endothelial cells displayed profound changes indicating cytoskeletal lesions and increased cell membrane permeability. Readapted cells of subsequent passages exhibited persisting cytoskeletal changes, decreased metabolism and cell growth indicating cellular senescence.
Melanoma is a lethal skin cancer that occurs predominantly among Caucasians. In Malaysia, the incidence of melanoma is low. This is a retrospective study of clinical and histopathological features of patients with cutaneous melanoma who were seen at the University Malaya Medical Centre from 1998 to 2008. Thirty-two patients with cutaneous melanoma were recorded during that period. Of these, 24 had sought treatment at the onset of disease at our centre. Chinese patients constituted the largest group (19 cases). The median age of these 24 patients at the time of presentation was 62 years. 16 patients had melanoma involving the lower limb with 12 affecting the sole of the foot. None had melanoma arising from the face. Histopathology showed nodular melanoma in 22 cases (91.6%), with superficial spreading and acral lentiginous melanoma diagnosed in 1 case each. The majority of patients (62.5%) were found to be in Stage III of the disease at the time of diagnosis.
Acral melanoma has been reported to have distinctive clinical presentation and ethnic distribution compared to other histological types of malignant melanoma. Acral melanoma also exhibits distinctive focused gene amplifications, including cyclin D1 overexpression. We reviewed archived histological material of malignant melanoma in the Sarawak General Hospital from year 2004 to 2010. 43 tumours, comprising 28 acral melanoma and 15 non-acral melanoma, had sufficient material to be included in the study. The majority (36%) of acral melanoma tumours occurred in the heel. The tumours were analyzed for cyclin D1 expression by immunohistochemistry. 68% of acral melanoma were cyclin D1 positive compared to a positivity of 33% in non-acral tumours. This difference was statistically significant (p < 0.05). This finding may improve the histological diagnosis of acral melanoma and detection of positive resection margins.
Although there have been many new developments in the treatment of leukaemia with the use of new anti-leukaemic agents and stem cell transplantation, drug resistance and treatment failure remain a great challenge for the attending physician. Several studies have suggested that leukaemic stem cells (LSCs) play a pivotal role in chemoresistance and metastasis and the mechanisms by which these cells do so have also been elucidated. There is increasing evidence to show that there exists a large pool of therapeutic targets in LSCs and that the eradication of these cells is feasible with some promising results. This article gives an overview of different types of cancer stem cells (CSCs) derived from various types of leukaemia, the mechanisms by which LSCs contribute to drug resistance and metastasis and some recent advances in targeted therapy against LSCs.
The advent of leukocyte filters has enabled effective removal of leukocytes from certain blood products thus avoiding many adverse effects of blood transfusion. Many different materials have been incorporated into these filters to achieve >95% leukocyte removal. In this study we evaluated the efficacy of leukocyte removal of two different filters, using actual bedside transfusion settings involving patients with transfusion dependent thalassaemia. Fifty-one transfusion events were randomised to use either a polyurethane filter or a non-woven polyester filter. We found that the two filters achieved 98.4% and 96.2% leukocyte removal respectively (p = 0.022). We also found no significant correlation between pre-filtration white blood cell count and the volume transfused with the efficacy of leukodepletion. No untoward events or transfusion reactions were observed during the study.
Detection of microalbuminuria is important in the management of diabetic patients since it is predictive of development of proteinuria and nephropathy. Two sensitive and specific in-house ELISAs for microalbuminuria were established and validated. One of the ELISAs was based on antigen coating while the other employed antibody coating. Recovery and linearity experiments gave acceptable results of 100 +/- 10%, while precision results were <10% for intra-assay and <12% for inter-assay coefficients of variation (CVs). The standard curve ranged from 10-625 ug/l, equivalent to 0.2-12.5 mg/l for urine samples diluted 1:20 fold. When the antibody coated ELISA was compared to antigen coated ELISA, a correlation of r=0.996 was obtained. When compared to commercial kits, the in-house ELISAs gave good correlations of r=0.961 versus the Boehringer Mannheim Micral Test strips and r=0.940 versus Ames Microalb Turbidimetry. The normal microalbumin reference ranges determined for 12h, first morning and random urine samples were 0.7-5.3 mg, 0.1-10.2 mg/l and 0.8-26.1 mg/l respectively. The normal albumin excretion rate (AER) was 1.0-7.3 ug/min while untimed urine samples gave results of 0.1-0.9 and 0.2-1.6 mg/mmol after dividing by creatinine concentrations. The ELISAs were used to detect microalbuminuria in 338 random urine samples from diabetic patients. A high percentage 47.9% was found to be positive for microalbuminuria and 18.0% had macroalbuminuria >25 mg/mmol. Thus screening for microalbuminuria together with creatinine measurements using random urine samples can be used for management of diabetic patients.
Pure mucinous carcinoma (MC) of the breast is a relatively uncommon variant of breast carcinoma with distinctive histological and cytological features. In this study we have analysed fine needle aspiration (FNA) cytological material from 28 cases of MC of breast and correlated the cytomorphological features with histopathology. The 28 patients consisted of 27 females and one male patient. 14 patients were Chinese, 10 were Indian and four were Malay. Their ages ranged from 38 to 90 with a mean at 52 years. The left breast was involved in 17 and the right in 11 cases. The duration of the lump varied from two weeks to 10 years. The cytological picture was characterized by abundant extracellular mucin giving a "sea of mucin" or "whirlpools of mucin" effect, in which were seen floating clusters of tumour cells with relatively bland cytological features. Myxo-vascular fragments were seen in 12 cases. Dissociated tumour cells showed a plasmacytoid appearance with eccentric nuclei. In four cases, the mucin was scanty in amount and the cellularity was high while in two cases, the cellularity was very low. Psammoma bodies were seen in cytological smears in one case. Histological study of excision or mastectomy specimens confirmed all 28 cases to be pure MC. Knowledge of the distinctive cytomorphological appearance of MC would enable correct identification of these lesions as malignant and prompt treatment that could further enhance the survival of these prognostically good breast cancers.
"Parenteral" or "serum" hepatitis is known to have afflicted man for centuries. However, it was not until the mid-1960s that the causative agent of this infection, the hepatitis B virus, was discovered. Since then, the biology and the replication strategy of the virus, and the clinical features and the epidemiology of the hepatitis B infection have been determined. Knowledge about the virus and the infection it causes led to the development of firstly, a plasma-derived vaccine and later a recombinant vaccine for the prevention of the infection. Integration of the hepatitis B vaccine into newborn vaccination programmes on a worldwide basis represents a major step in the effort to eliminate this infectious disease and its complications. Laboratory tests are available for the diagnosis and monitoring of the disease. Therapies have been developed to halt the progress of the chronic infection in affected individuals. While these developments have resulted in a decrease of the frequency of infection in many countries, particularly those that have implemented universal immunization of newborns, the chronic infection remains a significant global problem. Worldwide, over 300 million individuals are infected and each year, an estimated 1 million persons die from chronic complications of the disease including hepatocellular carcinoma and hepatic failure. The therapies currently available result in elimination of the virus in only a relatively small proportion of subjects and carry with it serious side effects. Geopolitical, economic and other factors hinder the vision of elimination of the infection through immunization programmes. Nevertheless, work continues to clarify further the underlying pathological mechanism of the infection, the host and viral factors that promote elimination or persistence of the virus in the human host. It is hoped that such investigations will reveal viral targets for the design of newer and potentially more effective drugs to treat the infection.
Virus isolation and accurate characterization plays a crucial role in the rapid identification of the causative agents of infectious disease outbreaks especially if the causative viruses are novel where no pre-existing diagnostic reagents would be available. A new cell culture tube, named Jui Meng (JM) Cell Culture Tube, was developed to reduce the cost and improve the efficiency and biosafety of work pertaining to virus isolation. The design of the tube is based heavily on the principle of practicability, functionality, biosafety and long-term cost saving for diagnostic laboratory work in virus isolation. It is designed to culture an initial inoculum of one milliliter of culture medium containing 1 x 10(4) to 1 x 10(5) cells/ml.
Factor VII deficiency is a rare congenital blood disorder. Its clinical features are rather variable and ranges from epistaxis to massive intracranial haemorrhage. Treatment involves replacement therapy, which constitutes use of fresh frozen plasma, prothrombin complex concentrates or recombinant activated factor VII. Although it is a rare entity, one still needs to consider it as a probable diagnosis in a newborn with coagulopathy. We report here a case of Factor VII deficiency in a newborn who presented with subdural haemorrhage at day 4 of life.
A 5-month-old Chinese male infant was referred to the University Hospital, Kuala Lumpur for persistent fever, generalised rash and abdominal distension. Clinically he was suspected to have haemophagocytic lymphohistiocytosis. Haematological findings including the presence of several abnormal giant granules in neutrophils and single large azurophilic granules in many lymphocytes and monocytes in the peripheral blood established the diagnosis of Chediak-Higashi syndrome. The patient responded to allogeneic bone marrow transplant. This paper discusses the characteristic features, clinical course and management of this rare disorder. We suggest that peripheral blood film examination for the abnormal giant granules in granulocytes is an essential investigation in all young children with frequent recurrent infections or who are suspected to have virus-associated haemophagocytic syndrome or familial haemophagocytic lymphohistiocytosis.