The applications of antibodies, be it monoclonal or polyclonal, in the diagnostic and research fields are well established. The disadvantage is the high cost of commercially available antibodies. In a diagnostic establishment like ours which also functions as a training ground for laboratory related personnel, it is beneficial to be able to produce in-house reagents. Therefore, we have undertaken this project to produce a rabbit polyclonal antibody against B lymphocytes. We found that the rabbit was a good choice because the titre of antibody produced was high and positive reactions were still detected at a dilution of 1:38400. The antibody showed significant positive reaction only with the lymphocyte subpopulation. A positive reaction was observed between the immunized rabbit serum and B lymphocytes but not T lymphocytes. This shows that the antibody was B lymphocyte specific. There was a positive correlation between the percentage of B lymphocytes labelled using the commercial anti-CD19 monoclonal antibody and the in-house polyclonal antibody (n = 13, r = 0.7, p = 0.02). However, the percentage of cells labelled by the in-house polyclonal anti-B was lower than that by the commercial monoclonal anti-CD19. The fluorescence intensity of the polyclonal antibody was lower than that of the monoclonal. In general, the performance of the in-house polyclonal antibody can be considered as satisfactory. The rabbit serum was stored at -20 degrees C and no significant loss of activity was detected for over a period of 19 months.
Emergence of antimicrobial resistance in bacteria associated with community acquired infections has made the choice of empirical therapy more difficult and more expensive. The problems due to possible spread of MRSA to the community, emergence of penicillin resistance in S. pneumoniae, ampicillin resistance in H. influenzae, and multiresistance among common enteric pathogens are highlighted. Bacteria have a remarkable ability to develop resistance to many of the newly synthesized antimicrobial agents but the appropriate use of antibiotics will delay and in many cases prevent the emergence of resistance.
Determining the racial affinity of an unknown individual from dentition for identification is indeed a difficult endeavour. However, there are certain dental characteristics which are predominant in certain racial groups and these contribute important indicators in the identification process. Inherited dental characteristics are modified by prenatal and postnatal environmental and nutritional conditions. They can also become less discernible due to admixture of the various races.
A specific enzyme immunoassay (EIA) for the diagnosis of hepatitis C virus (HCV) infection was developed by recombinant DNA technology. Abbott HCV EIA was used to detect antibody to HCV (anti-HCV) in non-transfused and multiply-transfused thalassemia patients. None of 11 non-transfused patients had anti-HCV but 3 of 52 (5.8%) multiply-transfused patients had anti-HCV. This study showed that the prevalence rate of HCV infection is low in thalassemia patients. However, it is still important to identify hepatitis C virus infected patients in high risk groups because hepatitis C is associated with chronic hepatitis, cirrhosis and hepatocellular carcinoma.
Cefepime is a new cephalosporin antibiotic which is highly active against both Gram-positive and Gram-negative organisms. The purpose of this study was to establish the in-vitro activity of cefepime and three other cephalosporins against recent clinical isolates from patients at the General Hospital Kuala Lumpur. A total of 334 strains comprising Enterobacteriaceae, non-fermentative Gram-negative bacilli and Staphylococcus aureus were tested for their sensitivity to cefepime, cefotaxime, ceftriaxone and ceftazidime. Minimum inhibitory concentrations of the antibiotics were established using an agar dilution method. With the exception of some strains of Flavobacterium meningosepticum, Xanthomonas maltophilia and other non-fermentative Gram-negative bacilli, cefepime was found to be active against a wide range of Gram-negative organisms. Cefepime was as or more active than the other cephalosporins against Acinetobacter, Enterobacteriaceae and methicillin-sensitive Staphylococcus aureus. Strains of Klebsiella and Salmonella that were resistant to the third generation cephalosporins were sensitive to cefepime. Cefepime could be a valuable alternative for the treatment of nosocomial infections due to multiply resistant organisms.
A review of gestational trophoblastic disease diagnosed at the Department of Pathology, University Hospital, Kuala Lumpur from January 1989 to December 1990 using established histological criteria showed 25 complete hydatidiform moles (CHM), 11 partial hydatidiform moles (PHM), 1 invasive mole and 2 choriocarcinoma. The ages of the patients with CHM ranged from 21 to 43 years (mean = 28.5 years) and PHM 20 to 33 years (mean = 27.5 years). The invasive mole occurred in a 42-year-old Malay woman. The two patients with choriocarcinoma were both Chinese and 41 and 46-years old respectively. During the same period, 1,062 non-molar abortions and 13,115 births, inclusive of livebirths and stillbirths were recorded at the University Hospital. The incidence rate of hydatidiform moles was thus estimated to be 1:384 pregnancies. PHM constituted 30% of all molar pregnancies. Hydatidiform moles occurred among the Malays, Chinese and Indians at the rate of 2.43, 2.66 and 3.29 per 1,000 pregnancies respectively. It appears that hydatidiform molar pregnancy has the highest prevalence among the Indians, a finding similar to an earlier Singapore study.
Our experience with 1,094 consecutive fine needle aspirations (FNAs) of the breast in 918 cases is presented. Correlation between the FNA cytology and subsequent histology of the lesions was available in 211 cases. FNA had a sensitivity rate of 87.3%, a specificity rate of 99.3% and a positive predictive value of 98.2%. A false negative diagnosis rate of 5.1% occurred. The overall diagnostic accuracy rate was 95.7%.
The distribution of immunoregulatory cells in the peripheral blood of an individual has now been established as an important tool in helping the management of several diseases. It is necessary to set the normal ranges of these cells for the laboratory. We have undertaken in this study to establish the reference ranges for normal Malaysian adults. We found that the mean percentages of T cells, B cells, T Helper cells (CD4), T suppressor cells (CD8), NK cells and the ratio of CD4/CD8 were 70.91%, 11.38%, 38.15%, 37.76%, 17.45%, and 1.00 respectively. There was no significant difference between the sexes. In certain parameters, there was significant differences between Malay, Chinese and Indians. The Chinese and Indians were significantly different in the distribution of B cells and in the CD4/CD8 ratio. In the case of CD4 and NK cells, the Indians were different from the other two groups.
A simple, non-isotopic in-house enzyme-linked immunoabsorbant assay (ELISA) for human growth hormone (GH) was developed. The assay involved using in-house polyclonal anti-GH adsorbed onto 96-well microtitre plates, commercially prepared mouse monoclonal anti-GH, and goat anti-mouse IgG horseradish peroxidase detection system. Results of recovery and parallelism studies ranged from 95%-106% and 98%-101% respectively, of the expected values. The detection limit of the assay was 0.008 mIU/well or the equivalent to 0.4 mIU/L of undiluted serum. Intra- and interassay coefficients of variations were 4.8%-7.9% and 6.5%-8.7% respectively. Serum GH levels measured in this assay correlated well with those measured in established in-house radioimmunoassays (r = 0.985, p < 0.001) and immunoradiometric assay from NETRIA (r = 0.984, p < 0.001).
Forty-four serum samples of various reactivities to rickettsial antigens demonstrated by the indirect immunoperoxidase technique were tested with INDX Dip-S-Ticks (INDX Integrated Diagnostics Inc., USA) Kit for the detection of tick borne diseases. The kit utilised Rickettsia rickettsii the causative agent of Rocky Mountain spotted fever (RMSF) as antigens. The samples positive for endemic typhus were also tested against R. typhi, the agent for endemic typhus by the same method. The aim of this study was to determine the extent of cross-reactivity of R. rickettsii with rickettsial infections in Malaysia. Nine out of 12 tick typhus, 4 out of 10 scrub typhus and 4 out of 12 endemic typhus samples cross reacted with R. rickettsii. Ten out of 12 endemic samples were positive with R. typhi by the same method. From the study, we concluded that the INDX Dip-S-Ticks Kit can be used as a rapid screening test to detect endemic and tick-borne rickettsial infections in Malaysia but a second serological test is strongly recommended on all weakly reactive cases.
Dengue fever is endemic in Malaysia with frequent epidemics especially in urban areas. This infection can present in a wide range of severity, from a nonspecific febrile illness to life threatening dengue haemorrhagic fever and dengue shock syndrome. It is worth noting that dengue haemorrhagic fever comprised 11.2% of all reported cases in Malaysia in 1991.Patients tend to consult their primary care physicians early. It is the duty of the primary care physicians to make an accurate diagnosis and to detect the complications. However, there has not been any known reliable predictor for the occurrence of complications during the early stage of the illness. Hence, primary care physicians often face the problem of having to deal with this uncertainty. Referring all these patients to the hospitals for admission is obviously not practical but managing them at home may involve high risks. In order to assist primary care physicians, the Primary Care Unit in the University Hospital uses a set of guidelines for the outpatient management of the infection. These guidelines and their assessment will be discussed.
Study site: Primary Care clinic, University Malaya Medical Centre, Kuala Lumpur, Malaysia