The aim of this study was to optimize the conditions for the passive adsorption of polyclonal antibody onto plain surface polystyrene latex particles and its performance in a slide latex agglutination test for rotavirus antigen detection. Cleaning of latex particles by washing through repetitive centrifuging, decanting and resuspending in distilled water was adequate in removing surfactants from the particles' surfaces to enable coating. A study of antibody concentration, incubation temperature and buffer pH revealed that optimum coating was achieved with a 3-fold excess of antibody to the calculated total particle surface capacity for the antibody in a glycine-saline buffer of pH 9.2 at 40 degrees C for 4 hours. The ionic strength and pH of the latex suspending buffer and the sample buffer were critical factors determining the sensitivity of the test and the appearance of non-specific agglutination. Ultrasonication, addition of glycerol and Tween 20, either individually or in combination, were able to suppress non-specific agglutination in some batches of latex reagents. Polyethylene glycol 6000 enhanced the quality of agglutination as well as reduced the time of its appearance, especially in reagents that produced poor agglutination.
An analysis of 1000 consecutive, adequate renal biopsies from patients of the University Hospital Kuala Lumpur between 1982 and 1991 revealed: minimal change nephritis (20.7%), focal glomerulosclerosis (2.9%), proliferative glomerulonephritides (16.0%), membranous glomerulonephritis (5.5%), IgA nephropathy (18.5%), lupus nephritis (24.9%), end stage nephropathy (3.1%) and others (8.4%). Compared with the previous decade, IgA nephropathy has emerged as a common entity. Lupus nephritis forms the largest diagnostic entity and is probably related to the selected referral of SLE patients to this hospital.
The surge of information on the aetiological association of the human papillomavirus (HPV) with some epithelial tumours emanating from various centres has prompted the initiation of a large-scale retrospective study at the Department of Pathology, University Hospital Kuala Lumpur to determine the prevalence and importance of this virus in some epithelial tumours of Malaysian patients. A retrospective analysis of 100 cases of large cell non-keratinising carcinoma of the uterine cervix by in-situ hybridisation on archival formalin-fixed, paraffin-embedded tissue has revealed the presence of HPV type 16 in 47% and type 18 in 41% of cases. This gives an overall detection rate of 88% of the two HPV types most commonly encountered in cervical carcinomas. Except for the unusually high frequency of HPV 18 detected in the cases, the overall prevalence is comparable to that reported in studies from most other centres. Although this higher frequency of HPV 18 may be due to geographical variation, the selection of the large cell non-keratinising type of squamous cell cervical carcinoma for study remains a possible reason for this phenomenon. In comparison to cervical carcinomas, HPV appears to be uncommon in penile carcinomas and HPV 6 was detected in only 1 of 23 cases studied.
Fifty-nine cases of tuberculous cervical lymphadenitis were analysed histologically. Characteristic epithelioid cell granulomas were seen in all the cases with central areas of caseation necrosis in 96.6% (57/59) of these cases. The diagnosis of tuberculosis was further established by the demonstration of acid-fast bacilli (AFB) in the tissue sections in 29 cases. These AFB, although occasional, were found more frequently within the epithelioid cells as compared with other zones of the granuloma. There was no significant association between necrosis and bacillary content. We conclude that light microscopical assessment is still a useful screening method to diagnose tuberculosis in cases of cervical lymphadenopathy.
Mucins are produced by both benign and malignant gastric epithelium. In general, mucins can be classified into neutral and acidic mucins. The latter are of 2 major types, sulphated (sulphomucins) and carboxylated (sialomucins). A retrospective study was initiated at the Department of Pathology, University Hospital, Kuala Lumpur to histochemically study the mucin profiles of cases of intestinal (IGC) and diffuse (DGC) types of gastric carcinoma in Malaysian patients to determine whether a significant change of mucin type occurs in the event of malignant transformation. 42 IGC and 37 DGC were subjected to alcian blue-periodic acid Schiff and high iron diamine-alcian blue histochemical staining. In addition, 18 cases of gastrectomies performed for benign lesions in the stomach served as normal controls. The number of cases of IGC and DGC which exhibited sulphomucin production was significantly increased (p < 0.001) compared to normal controls. Also, the number of cases of DGC which produced neutral mucin were significantly less (p < 0.05) than the control group. However, there was no significant difference between the number of IGC and DGC cases which demonstrated sialomucin production and normal controls. It appears that while not pathognomonic, a lack of neutral mucin production should alert the pathologist to the possibility of a gastric malignancy, in particular DGC. The likelihood of a malignant lesion would be further supported if there is an increased sulphomucin production.
Congo red screening of routine biopsies at the University Hospital Kuala Lumpur revealed the following categories of amyloidosis: systemic AL (5.9%); systemic AA (3.2%); isolated atrial (14%); primary localized cutaneous (7.5%); other primary localized deposits (3.2%); localized intratumour (58%); and dystrophic (8.6%). Unlike in the West, AA amyloidosis in this population was usually secondary to leprosy or tuberculosis. Liver involvement in AL amyloidosis was shown to exhibit a sinusoidal pattern and differed from the vascular pattern of AA amyloidosis. Within the category of AA amyloidosis, there were two patterns of renal involvement--glomerular and vascular, with the glomerular pattern carrying a more ominous clinical picture. Notable among the localized amyloidoses were isolated atrial amyloidosis complicating chronic rheumatic heart disease, intratumour amyloidosis within nasopharyngeal carcinomas and dystrophic amyloidosis which occurred in fibrotic tissues.
Leprosy is a chronic infectious disease and is still a public health problem in Malaysia. In 1926, the Leper Enactment Act was established which required compulsory notification and isolation of leprosy patients. As a result, the National Leprosy Control Centre (NLCC) was built in Sungai Buloh, Selangor. In 1969, the National Leprosy Control programme was launched with the objective of early case finding and decentralisation of treatment of leprosy. The treatment of leprosy patients is integrated with basic Medical and Health services in Malaysia. With the implementation of multiple drug therapy in 1985, the National prevalence rate of leprosy has reduced from 5.7 per 10,000 in 1983 to 1.7 per 10,000 in 1992. The Research Unit in NLCC was established in 1950, where cultivation of Mycobacterium leprae using mouse foot-pad technique is done. This technique is used for assessment of efficacy of chemotherapeutic agents in leprosy. Research activites are also done in collaboration with the Institute for Medical Research in Kuala Lumpur such as isolation of Mycobacterium leprae antigen using T cell clones and phenolic glycolipid antigen.
Chronic hepatitis B virus (HBV) infection constitutes a major public health problem particularly in developing countries in East Asia, South-East Asia, the Pacific Basin and Africa. In Malaysia, a developing nation in the South East Asian region, the chronic HBV carrier rate varies between < 1% to about 10% depending on the ethnic group studied. The highest frequency is seen among the Chinese, followed by the Malays and lastly the Indians, with a male preponderance of between 2 : 1 and 3 : 1. Exposure to the virus among the adult population is estimated to be about 15%, 26% and 36% among the Indians, Malays and Chinese respectively. Serological study of adult chronic HBV carriers showed a frequency of HBe antigenemia of about 35%, with a significant decreasing trend with age. HBV DNA status generally correlated with the HBe status. An atypical profile of anti-HBe associated with serum HBV DNA is found in some carriers; in most instances, this is related to seroconversion from HBe antigenemia to anti-HBe. Chronic complications of HBV infection include the development of hepatocellular carcinoma (HCC), the occurrence of which closely parallel that of HBsAg carrier rate. In Malaysia, HCC is the third most common malignant neoplasm and among the 10 leading causes of death. About 80% of our HCC cases are HBV associated. All 3 ethnic groups are afflicted, the highest frequency being among the Chinese. Males show a disproportionate risk with an odds ratio of 3.93 (p < 0.0001).
A detailed cytomorphologic study was done on fine needle aspiration smears from 651 benign breast lumps. Cytological categorization enabled the distinction of proliferative from non-proliferative and infective lesions in the majority of the cases. Lumpectomy provided the histological diagnosis in 584 cases, most of which were proliferative lesions. Gross cystic disease and fibroadenoma were the most common lesions encountered. Microcysts with apocrine change, sclerosing adenosis, proliferative disease without atypia, atypical ductal hyperplasia, atypical lobular hyperplasia, and lobular carcinoma in situ were associated with the dominant lesion in many of the cases. In all these cases, retrospective analysis of the cytological smears was done in an attempt to identify cytological features which may indicate these lesions.
In Malaysia, alpha-thalassaemia, beta-thalassaemia, haemoglobin (Hb) E, deltabeta-thalassaemia and Hb Constant Spring are prevalent. It has been estimated that 1 in 4 persons carries one of the above genetic abnormalities. In clinical practice, the major problems are: Hb Bart's hydrops fetalis (homozygous alpha(o)thalassaemia), homozygous 3(o)-thalassaemia, E-alpha thalassaemia and HbH disease. The laboratory procedures for diagnosis are standardised and the molecular basis of most of these genetic abnormalities are characterised. Thus it is possible to formulate a strategy for the detection and prevention of these disorders. The steps include the setting-up of population screening and genetic counselling service for the affected individuals, Society of Thalassaemias for public education and group support, and prenatal diagnosis with selective abortion of affected pregnancies. We embarked on such a programme between 1988 and 1992 in Kuala Lumpur General Hospital and hope to kindle similar effort in other state hospitals.
A 37-year-old Chinese male presented with an acute abdomen. Surgical exploration revealed duodenal perforation, extensive small bowel infarction and peritonitis. Histopathology of the resected bowel showed characteristic features of classic polyarteritis nodosa. The latter also involved mesenteric arteries in the form of tiny aneurysms. Steroids could not be started due to: (i) overwhelming microbial infections and (ii) fear of more perforations in other areas of the bowel. Such a presentation of polyarteritis nodosa is uncommon. Its recognition prior to surgery, management and prognosis is discussed.
Several fixation and permeabilization techniques that enable the flow cytometric analysis of the cell contents have been introduced in recent years. These methods allow sensitive detection of intracellular antigens that facilitates the diagnosis of certain diseases. We have undertaken in this study to evaluate a simple method of fixation and permeabilization using 2% paraformaldehyde and Tween 20. Intracellular antigens in three different leukaemia cases were analysed. We found that the method was reliable and easy. Intracellular kappa light chains were found in abundance in a case of plasma cell leukaemia. CD3 and CD22 were found in greater amount intracellularly than on the surface in pre-T-ALL and pre-pre B-ALL respectively.
A 35-year-old Chinese man who was known to have insulin-dependent diabetes mellitus was admitted for fever and weight loss. During his hospital stay, he fell to his death from his ward at the twelfth floor. The clinical features, radiological findings and gross organ changes at autopsy closely simulated miliary tuberculosis. Histology, however, revealed extensive necrosis of the adrenal glands, lungs, spleen, kidneys and thyroid associated with the presence of Histoplasma capsulatum organisms. This case highlights the similarity both clinically and pathologically between histoplasmosis and tuberculosis and emphasizes the need to be aware of this infection in a nonendemic area among patients with a compromised immune system.
The changes in serum prealbumin (transthyretin) and serum albumin in acute and chronic liver diseases were investigated. Albumin has long been used as a useful indicator of liver function but serum prealbumin has recently been noted for its clinical significance in acute liver diseases. Serum prealbumin concentrations and liver function tests (albumin, bilirubin, alanine aminotransferase) were determined on blood obtained from normal donors (n = 148) and from patients suffering from liver diseases (n = 78) such as acute viral hepatitis, chronic active hepatitis, cirrhosis and hepatoma. The mean serum prealbumin concentration in normal subjects was 29.6 +/- 4.82 mg/dl while the mean serum prealbumin concentration in patients with liver disease was greatly reduced (acute viral hepatitis = 15.3 +/- 7.4mg/dl; chronic active hepatitis = 10.2 +/- 6.6mg/dl; cirrhosis = 9.9 +/- 6.4mg/dl and hepatoma = 10.7 +/- 4.2). Albumin concentrations dropped slightly (13% compared to control) in acute viral hepatitis but dropped markedly (28% compared to control) in chronic liver diseases. The study suggests that serum prealbumin concentration might be a more sensitive indicator than albumin in assessing liver dysfunction in acute liver diseases.
The Epstein-Barr virus (EBV), traditionally linked etiologically with infectious mononucleosis (IM), endemic Burkitt lymphoma (BL) and nasopharyngeal carcinoma (NPC) has in recent years been associated with a host of other conditions. Viral strategies for entry into cells and persistence, as well as various molecular mechanisms involved in latency, replication and transformation have been elucidated. EBV termini analysis has demonstrated the essentially clonal nature of BL, NPC and preneoplastic lesions of the nasopharynx. Strain variation between isolates of EBV suggests that differences in epithelial cell tropism among strains may exist. Treatment of EBV-associated syndromes is largely supportive although antivirals may play a role in the management of oral hairy leukoplakia. At the present time, the development of an effective vaccine remains a viable proposition.
HIV-1 antibody patterns in two groups, those infected by the intravenous route (IV drug users) and those infected by the sexual route (prostitutes, male homosexuals and sexually transmitted disease patients) were compared using the Western blot technique. A total of 160 cases were studied. The intravenous drug user (IVDU) group appeared to respond to fewer antibody markers than the sexually infected group, the difference being significant for markers p31, p51, p55, p66, gp41 and gp120. Furthermore, a higher proportion (63%) of the sexually infected group carried antibodies to all Western blot markers as compared to the IVDU group (49%).
Forty-eight patients with breast carcinoma were subjected to four quadrant fine needle aspiration (FNA) cytology examination of the ipsilateral and contralateral breast in an attempt to detect any accompanying benign proliferative lesion. Mastectomy of ipsilateral and open biopsy of contralateral breast provided material for histopathological study. Cytological evidence of epithelial proliferation was found in 8 (16.6%) cases which included atypical lobular hyperplasia (ALH), lobular neoplasia in-situ (LNIS), atypical ductal hyperplasia (ADH), and proliferative disease without atypia (PDWA). In lobular proliferative lesions, cytological smears showed configurations of cells that resembled filled up or expanded lobular units. The cytology was not distinctive enough to distinguish the sub-types of lobular proliferations. Likewise, the presence of ductal alterations could be suggested by cytological study but the distinction of proliferative disease without atypia (PDWA) from atypical ductal hyperplasia (ADH) was not possible on a cytological basis.
An invasive aspergillosis model in rabbits was attempted using 3 concentrations of A. fumigatus conidia. Conidia concentrations of 1 x 10(6), 1 x 10(7) and 1 x 10(8) were inoculated intravenously into rabbits. The severity of infection was directly proportional to the inoculum size of the conidia. Aspergillus fumigatus was isolated from livers, kidneys, spleens, hearts and lungs of infected rabbits at a rate of 82%, 75%, 57%, 54% and 32% respectively. Cultures of urine specimens taken by bladder tap were positive for A. fumigatus in 30% of the rabbits tested. Blood cultures using the Bactec Fungal System (Becton Dickinson Corp., USA) failed to isolate A. fumigatus in 20 rabbits with biopsy-proven invasive apergillosis. Active infection with high fungal tissue burden occurred between 2-4 days after infection in rabbits inoculated with 1 x 10(7) conidia.
The direct assay of serum progesterone after denaturation of the binding proteins was investigated. 50ul of patients' serum was diluted with 750ul phosphate buffer (0.05M, pH 7.4) and heated to 65 degrees C for 20 minutes. After cooling, 300ul of the treated serum was reacted with a rabbit antiserum to progesterone-11 alpha-hemicuccinyl-bovine serum albumin conjugate (Bioclin, U.K) and 1,2,6,7, tritium labelled progesterone. Separation of bound and free fractions was achieved with dextran coated charcoal. The method correlated well (r = 0.98) with an established method involving ether extraction of progesterone prior to assay. The mean sensitivity was 2.01 nmol/L (range 1.90-2.23nmol/L). The proposed method considerably shortens assay time and removes a tedious and imprecise stage in the conventional method involving extraction of serum.
Seventy-eight symptomatic females without palpable breast lumps were subjected to bilateral four quadrant fine needle aspiration cytology. Cytological evidence of an epithelial proliferative lesion was seen in 44 of these cases. Based on the cytological evidence of proliferation, the site for open biopsy was determined. Histopathological study of the breast biopsies in these patients showed proliferative disease without atypia (PDWA) in 40 cases, atypical ductal hyperplasia (ADH) in two, atypical lobular hyperplasia (ALH) in one and ADH with ALH in one case. Cytology was thus useful in establishing the presence of proliferative activity, commenting on the extent of proliferation, and thereby roughly mapping out the area of the breast most suitable for biopsy. On cytological grounds, it was not possible to distinguish the atypical hyperplastic lesions from the proliferative diseases without atypia.