This study aimed to determine the role of surfactant protein A (SP-A) in the formation of stable microbubble in tracheal aspirates. Our results showed that as the concentration of anti SP-A antibodies added to tracheal aspirate specimens increased, the number of stable microbubble formed in the specimen decreased. The correlation between stable microbubble counts and the SP-A levels in the tracheal aspirates was good, r = 0.85, p < 0.05. This study suggests that SP-A plays an important role in stable microbubble formation. Measurement of small stable microbubbles is thus a useful bedside test for predicting the SP-A activity in the tracheal aspirates and in indirect measurement of lung maturity.
780 breast cytology samples obtained over a one year period at the Breast Clinic of the University Hospital, Kuala Lumpur were reviewed. These included 745 fine needle aspirates (FNA's) and 35 nipple smears. The broad categories of cytodiagnoses were as follows: malignant: 95, suspicious or equivocal: 26, benign: 543, no proliferative lesion: 58 and inadequate: 58. The benign and malignant lesions were also subcategorized on cytological basis. The suspicious or equivocal lesions were subjected to biopsy and 17 of these proved to be malignant. 194 cases that were subjected to histological confirmation and 34 cases that were considered to be undisputably malignant (on the basis of clinical features, recurrences, metastases, etc.) were subjected to statistical analysis (total 228 cases). If the cytologically suspicious/equivocal category was considered as "test positive" the sensitivity of cytodiagnosis was 97.4% and the specificity 92%. The high degree of cytodiagnostic sensitivity and specificity make breast cytology a valuable adjunct in the evaluation of breast lesions.
This study was undertaken to see if liver function tests (LFT) served a worthwhile purpose in the investigation of hepatocellular carcinoma (HCC). Sera from 80 HCC, 76 benign liver disease (BLD) and 152 healthy adult (HA) subjects were assayed for alkaline phosphatase (ALP), gamma-glutamyltransferase (GGT), aspartate aminotransferase (AST), alanine aminotransferase and lactate dehydrogenase, bilirubin and albumin. Cut-off values were determined from the HA. ALP, GGT, AST and albumin were abnormal in about 90% of the HCC. With the exception of bilirubin, the LFT were abnormal more frequently in HCC than in chronic hepatitis and cirrhosis, the conditions which preceed it. Raised ALP in the presence of normal bilirubin was more often a feature of HCC than BLD although this relationship was not statistically significant. It seems unlikely that LFT serve a useful function in HCC.
The Serodia-HCV Particle Agglutination (HCV-PA) for the detection of HCV antibodies was compared with the Enzyme Immunoassay Test (UBI HCV EIA) for possible in-house use. A total of 150 specimens were analysed using UBI HCV EIA and Serodia-HCV PA. Of these, 80 (53.3%) were both PA and EIA positive and 59 (39.3%) were negative by both techniques. Eleven sera (7.4%) were found to be EIA-positive but PA-negative. These 11 discordant sera were further tested by the LiaTek-HCV III Immunoassay (Organon Teknika). Ten were found to be line immunoassay negative and one was line immunoassay positive. Failure of the PA to detect the HCV positive serum meant that a small proportion of HCV antibody positives may be missed by the PA test. We conclude that (i) EIA should continue to be the first line screening test in our laboratory, (ii) PA with its 100% specificity could be a useful supplementary screen for all EIA-positive sera and finally (iii) line immunoassay could be used on sera to resolve discordant results in the EIA and PA assays.
Fine needle aspiration (FNA) cytology is now an integral part of the pre-operative investigation of breast lesions and the therapeutic protocol is today often planned on the basis of cytodiagnosis. However, from time to time the cytological picture may be equivocal or inconclusive. In recent years, nucleolar organizer region (NOR) scores have been explored for potential value in the diagnosis of malignancy as the scores in malignant nuclei are seen to be higher than in benign or reactive nuclei. With a view to applying NOR scoring in the evaluation of cytologically equivocal cases, we adopted the argyrophil technique for staining NOR s (AgNOR) in FNA cytological smears of 56 breast lesions, comprising 31 benign and 25 malignant lesions. Histological correlation was possible in 26 of these cases (17 malignant and 9 benign) and AgNOR scoring was done on paraffin sections of these as well. There was a significant difference between mean AgNOR scores in benign and malignant lesions in the cytological smears (P < 0.001). The AgNOR scores ranged from 2.5 to 5.0 per cell in benign lesions and 5.8 to 17.2 per cell in malignant lesions. None of the cases fell into the gray zone of overlap. One malignant lesion that was cytologically equivocal showed a mean AgNOR score of 6.08. The AgNOR scores on histological sections also showed a statistically significant difference (P < 0.001) between benign and malignant lesions with mean scores ranging from 1.34 to 2.58 dots per cell in benign lesions and scores of 2.42 to 5.28 dots per cell in malignant lesions. However, the scores overlapped in four cases and therefore it was considered unsuitable for routine diagnostic work. From this preliminary study, we conclude that an FNA AgNOR score of 5.0 and less strongly favours a benign lesion whereas a score above 5.0 would be in favour of a malignant lesion. A larger study would be needed to verify our impression that AgNOR scoring can be useful in cytologically equivocal cases.
In an attempt to reduce costs, the role of Bactec anaerobic blood culture in the detection of bacteraemia and fungaemia in children was evaluated. Results from 3167 sets of aerobic and anaerobic blood cultures from children admitted to the University Hospital, Kuala Lumpur during a one year period, were analysed. Four hundred and eight (12.9%) sets of blood cultures were positive, of which 348 sets (11.0%) from 201 patients were clinically significant. Of the 348 significant positive sets, organisms were isolated on 177 (50.9%) occasions from both aerobic and anaerobic bottles, on 136 (39.1%) occasions from the aerobic bottle only and 35 (10.0%) occasions from the anaerobic bottle only. No strict anaerobes were isolated, but clinically significant isolates recovered from the anaerobic bottle only included Klebsiella pneumoniae, Salmonella species, Enterobacter cloacae, Staphylococcus aureus, coagulase negative staphylococci, Streptococcus pneumoniae and Group B streptococcus. Patients with bacteraemia diagnosed solely by anaerobic culture were distributed evenly across the various paediatric subspecialities. When results from the anaerobic bottles were excluded, the overall isolation rate was reduced from 11% to 9.9%. Potential financial savings resulting from omission of anaerobic cultures must be balanced against the small number of bacteraemic episodes that could be missed. Undiagnosed bacteraemia may result in increased morbidity and mortality with its own attendant financial implications.
Immunoreactive adrenocorticotropin (ACTH), beta-endorphin (BEP) and corticotropin-releasing factor (CRF) were detected in human term placenta obtained from elective Caesarian surgery. The concentrations of ACTH, BEP and CRF in placenta detected by radioimmunoassay (RIA) were 2.83 +/- 0.36, 0.52 +/- 0.05 and 0.56 +/- 0.15 ng/g wet weight of tissue respectively. Pro-opiomelanocortin (POMC) peptides were also detected in the amnion and chorion membranes and in the decidua. The concentrations of ACTH were 1.72 +/- 0.20, 4.43 +/- 0.39 and 5.80 +/- 0.17 ng/g and the levels of BEP were 0.42 +/- 0.18, 0.65 +/- 0.20 and 3.66 +/- 1.10 ng/g in the amnion, chorion and decidua respectively. In contrast to placenta, immunoreactive CRF was not detected in the amnion, chorion and decidua. Immunoreactive N-acetylated BEP was also not detected in all the placental subfractions. Comparison of the amounts of both ACTH and BEP in the various placental components indicated the following distribution: decidua > chorion > placenta > amnion. In decidua, POMC peptides were present in an equi-molar ratio but in the other three placental fractions, ACTH levels were three to five-fold higher than BEP. In immunohistochemical studies, only a positive staining for ACTH was obtained for decidua. Our results confirm the presence of POMC peptides and CRF in placenta and their physiological roles in pregnancy and parturition.
An in-house radioimmunoassay (RIA) for the measurement of androstenedione levels in serum was established and validated. Levels of androstenedione were measured by RIA using serum samples from various normal population groups and patients with congenital adrenal hyperplasia (CAH). Analytical recovery and linearity results were > 95%, while intra- and inter-assay CVs were < 10% and < 22% respectively. The assay sensitivity was 0.5 nmol/l or 25 fmol/tube. In normal population groups, the highest androstenedione levels were found in preterm neonates (1.6-12.4 nmol/l), followed by adult females (1.5-10.2 nmol/l), adult males (1.6-8.0 nmol/l) and term neonates (0.8-8.8 nmol/l), while the lowest values were observed in prepubertal children (0.5-3.4 nmol/l). There were no significant differences in diurnal variation and between follicular and luteal phases. The range of androstenedione levels in untreated or poorly controlled CAH patients (7.6-355.0 nmol/l, median 42.5 nmol/l, n = 20) were significantly higher (p < 0.001) than the upper normal limit of 3.4 nmol/L for prepubertal children. The normal androstenedione reference ranges for paediatric and adult groups have thus been established.
Since conventional radioimmunoassays (RIA) for measurement of 17-hydroxyprogesterone (17-OHP) in serum samples require a laborious solvent extraction step, a direct and rapid in-house RIA was developed for early diagnosis and management of congenital adrenal hyperplasia (CAH). In-house rabbit anti-17-OHP antiserum, tritium labelled 17-OHP and dextran-coated charcoal were used in assay buffer with low pH 5.1 and preheated serum samples. Both inter- and intra-assay CVs were < 10% and the sensitivity was 1.2 nmol/l or 12 fmol/tube. Results from the direct assay correlated well with values from an extraction assay, r = 0.88 in samples from CAH patients, r = 0.85 in adults and children, 0.69 and 0.40 in term and preterm neonates respectively, 0.66 and 0.63 in luteal phase and third trimester pregnancy; p < 0.001 in all groups except p < 0.05 in preterm neonates. However, results from the direct assay were two to three times higher in serum samples from CAH patients, normal adults and children, but were five to seven times higher in pregnancy and term neonates and thirty times higher in preterm neonates. The markedly elevated levels measured by the direct assay are probably due to cross-reactivities with water-soluble steroid metabolites such as 17-hydroxypregnenolone sulphate and dehydroepiandrosterone sulphate (DHEAS). Although the direct assay is only useful as a screening test for preterm babies, it can be used for both diagnosis and monitoring of treatment of CAH in all other age groups.
Two different preparations of monoclonal antibodies developed against respiratory viruses have been evaluated by the immunofluorescence antibody technique. The Chemicon monoclonal antibodies were found to be more efficient at picking up positive specimens with a high sensitivity and specificity than Imagen monoclonal antibodies. However, the overall concordance rate of the monoclonal antibodies was 92.3%-100%. Generally, when compared with cell culture isolation, the immunofluorescence antibody technique was found to be more sensitive. The high quality of the Chemicon monoclonal antibodies contribute to their value in providing definitive diagnosis, within a few hours of specimen collection, thus allowing early management of patients, their contacts and control of hospital infection.
The commercialization of health services has wide ranging implications for all medical specialties as well as for patients. Factors that must be considered include not only the financial implications, but also questions of quality and academic interests such as teaching and training. Laboratories must provide a service that the purchaser wishes to buy and must be successful in overcoming competition from the private sector. Each component part of the overall service must be analyzed in order that the laboratory is efficiently structured to provide an optimum service. A good understanding of management issues and a flexible approach are paramount in the provision of efficient, cost-effective and quality service for the ultimate benefit of the patient.
Although alpha-fetoprotein (AFP) is regarded as the reference marker for hepatocellular carcinoma (HCC), it sometimes produces false results. The objective of this study was to see if some of the readily available laboratory markers could complement AFP to improve the laboratory diagnosis of HCC. The markers tested and their sensitivities were: CA 125, 92%; ferritin, 71.3%; CA 19-9, 69.8%; beta-2-microglobulin (B2M), 53.3%; CA 72-4, 13.6%; and carcinoembryonic antigen (CEA), 10.6%. In comparison, AFP had a sensitivity of 58.8%. CA 72-4 and CEA (at the "tumour" cut-off level of 20 ng/ml) had specificities of 100%, and AFP, 97.4%. The specificities of the other markers were less impressive: CEA, 77.8% (at the cut-off level of 5 ng/ml); ferritin, 48.6%; CA 125, 48.5%; B2M, 39.6%; and CA 19-9, 37.3%. The efficiencies of the markers for HCC, which are based on the consideration of sensitivity and specificity together, were as follows: AFP, 77.6%; CA 125, 71.3%; ferritin, 60.5%; CA 19-9, 55.3; B2M, 46.9%; CEA, 40.8%; and CA 72-4, 34.5%. The receiver-operating characteristic plots confirmed AFP to be the most efficient marker for HCC. Nevertheless, it is proposed that CA 125 be combined with AFP for HCC screening because of their excellent sensitivity and specificity, respectively: a negative result for both, or even just CA 125 alone, would indicate that the disease is unlikely while a positive AFP (which would likely occur with a positive CA 125) would make its presence highly probable. A positive CA 125 and negative AFP would be equivocal for HCC. Other markers in combination with AFP are less useful.
The present study was undertaken to investigate the antibody responses of dengue fever (DF) patients to specific dengue virus proteins. Partially purified dengue 2 New Guinea C (NGC) strain virus was used as antigen. Under the present experimental protocols, it was observed that almost all DF patients' sera had detectable presence of antibodies which recognize the dengue 2 envelope (E) protein. The convalescent-phase sera especially had significant detectable IgG, IgM and IgE against the protein. In addition, IgGs specific against the NS1 dimer and PrM were also detected. Antibody against the core (C) protein, however, was not detectable in any of the DF patients' sera. The substantial presence of IgG against the PrM in the convalescent-phase sera, and the presence of IgE specific for the E, reflect the potential importance of these antibody responses in the pathogenesis of dengue.
One hundred and twelve infiltrating ductal carcinoma of breast were studied by the standard avidinbiotin complex immunoperoxidase method on formalin-fixed, paraffin-embedded tissue sections, using a monoclonal antibody to c-erbB-2 oncoprotein. The same tumours were assessed and scored according to the Bloom and Richardson criteria into three histological grades. The distribution of tumours according to grade were: 8 Grade I, 34 Grade II and 70 Grade III. Forty-three (38.4%) tumours showed positive membrane staining for c-erbB-2 oncoprotein. These comprised 7 Grade II and 36 Grade III tumours with c-erbB-2 immunopositivity rates of 20.6% and 51.4% respectively. The oncoprotein was not expressed by Grade I tumours. This study shows a good correlation between c-erbB-2 expression and histological grade, a known prognostic indicator of invasive breast carcinoma. Because the c-erbB-2 oncogene has extensive structural homology to the epidermal growth factor receptor gene, its overexpression can be expected to result in more aggressive tumour behaviour. While it may be regarded as another indicator of poor prognosis breast cancers, its value in the selection of carcinomas less responsive to hormonal therapy and those more suitable for immunotherapy than chemotherapy has been mooted but remains to be clarified.
A 39-year-old female presented with a mobile 1.5 cm nodule in the right breast. Fine needle aspiration cytology smears stained with May Grunwald Giemsa were highly cellular with a monotonous population of dissociated and clustered tumour cells that showed a bland cytological appearance with cytoplasmic vacuolation and occasional signet ring forms. Intracellular and extracellular mucus was present. Histological study of the excised breast mass showed a secretory carcinoma. This is a rare breast neoplasm in which cytological features are characteristic enough to permit a specific diagnosis on needle aspirates.
The International Working Formulation divides non-Hodgkin's lymphoma (NHL) into three grades: low, intermediate and high. This grading system implies rate of tumour growth and hence prognosis. Ki-67 antigen is a proliferation-related nuclear antigen and bcl-2 oncogene product is known to inhibit apoptosis. This study aimed to determine the pattern of expression of Ki-67 antigen and bcl-2 oncoprotein in various grades of NHL. Paraffin-embedded tissues from 42 cases of NHL (7 low, 15 intermediate, 20 high grade) were retrieved from the files of the Department of Pathology, University of Malaya. Ki-67 antigen and bcl-2 oncoprotein were detected using immunohistochemistry. The percentage of positively stained neoplastic cells was determined by semi-quantitative estimation and given scores ranging from 0 to 6. Partition chi square test demonstrated the association of Ki-67 antigen expression and histological grade (p = 0.007). There was no significant difference in Ki-67 antigen expression between intermediate and high grade malignant lymphomas (p = 0.28), whereas significant difference was demonstrated between low and intermediate/high grade tumours (p = 0.003). Bcl-2 oncoprotein expression in the neoplastic cells varied widely within the three histological grades. Statistical analysis showed no association between the expression of bcl-2 oncoprotein and histological grade (p = 0.25). Ki-67 immunostaining is therefore a useful adjunct to histological grading of NHL.
Moraxella catarrhalis has gained reputation as a pathogen in the lower respiratory tract especially in patients with underlying chronic lung diseases. It is considered significant when isolated from sputum specimens of adults with respiratory tract infections. A study was carried out to determine the prevalence of Moraxella catarrhalis isolated in sputum specimens and beta-lactamase production of these isolates. Sputum specimens sent to the Bacteriology division, Institute for Medical Research from April 1990 until April 1993 were screened for Moraxella catarrhalis. A total of 1678 sputum specimens were processed and Moraxella catarrhalis was isolated from 15 (0.89%) of the sputum specimens. Six out of 15 (40%) were isolated from patients with chronic lung disease. Eight out of 15 (47%) were beta-lactamase producers. Moraxella catarrhalis isolated in good-quality sputum must not be disregarded and should be looked for especially in patients with chronic obstructive pulmonary disease. Beta-lactamase production should be tested on all isolates so that appropriate treatment can be given. All the isolates in this study were sensitive to cotrimoxazole.
The relationship between serum Hepatitis B virus DNA (HBV-DNA) and the Hepatitis B e-antigen/ anti-Hepatitis Be (HBeAg/anti-HBe) serological status in Malaysians was studied. 212 cases of asymptomatic HBV carriers were recruited for this study. 92 cases were positive for the HBeAg at the point of recruitment. 85 (92.4%) of these patients tested positive for HBV-DNA, of whom 55 (64.7%) had levels over 100pg/ml of serum. Three of the remaining 7 HBeAg positive cases who were negative for HBV-DNA subsequently seroconverted. The other 4 cases remained negative for HBV-DNA for periods of 6-12 months. Out of 113 cases who were anti-HBe positive, 12 (10.6%) gave a positive HBV-DNA result. 2 of these 12 patients were recent seroconverters; the remaining cases had transiently increased viral replicative activity which later subsided. 7 out of the 212 carriers were in the e-window period; all 7 tested negative for HBV-DNA. Our data confirm a high frequency of HBV-DNA in HBeAg positive carriers and a negative correlation between HBV-DNA and anti-HBe. An atypical profile of anti-HBe associated with HBV-DNA was observed in 10.6% of the carriers. An inverse relationship between serum HBV-DNA levels and age was also observed.