Squamous cell carcinoma-related antigen (SCC-Ag), first described by Kato and Torigoe in 1977, has been cited by various workers as a serological marker for some epithelial neoplasms. The most well-studied is its association with carcinoma of the uterine cervix. In January 1989, we embarked on a prospective, multivariate study at the University Hospital, Kuala Lumpur to assess the usefulness of serologically assaying SCC-Ag (using the Abbott RIA diagnostic kit) in our patients with carcinoma of the uterine cervix. We were also interested to ascertain whether SCC-Ag is a 'general' marker for all histological types of cervical carcinoma or specific for squamous carcinoma. From the time of commencement to June 1990, 35 newly-diagnosed and histologically-proven cases were entered into the study. Of these, 4 were keratinising squamous carcinoma, 18 large cell non-keratinising carcinoma, 3 adenosquamous carcinoma, 7 adenocarcinoma and 3 carcinoma-in-situ. Our preliminary results show that all keratinising squamous carcinoma and 1/3 each of large cell non-keratinising carcinoma, adenosquamous carcinoma and carcinoma-in-situ had positive pre-therapy serum SCC-Ag levels (i.e greater than 2 ng/ml, 2 ng/ml being an arbitrarily selected 'cut-off' value). In contrast, no adenocarcinoma was serologically positive. In addition, keratinising squamous carcinoma had the highest mean pre-therapy serum SCC-Ag level. The results imply that serum SCC-Ag is related to the (1) presence of squamous and not glandular differentiation and (2) degree of squamous differentiation.
A total of 676 patients were admitted to the intensive care unit, University Hospital, Kuala Lumpur between January 1989 and March 1990. Fifty-one hospital-acquired infections were recorded, giving a rate of 7.6%. The most frequent site of infection was the respiratory tract (41.2%), followed by the urinary tract (27.5%). Most of the pathogens were gram-negative bacilli (71%). The three most common pathogens were Klebsiella species, Pseudomonas aeruginosa and Staphylococcus aureus.
As general pathologists in Malaysia are required to perform medico-legal autopsies, this paper is written with the hope that it may serve as a guide to the less initiated. An account of elementary ballistics is included because it is essential for understanding the features of wounds produced by firearms. A complete autopsy examination including a systematic approach to the injuries is advocated. The recognition and interpretation of firearm injuries can often be difficult and it is essential that all features of injuries and other relevant findings are carefully observed and recorded. Relevant observations, documentation and opinions necessary for accurate determination of the true circumstances of death are discussed.
Raised prolactin levels have been implicated as a cause for infertility in patients with endometriosis. This study was done to investigate if serum prolactin levels were significantly raised in infertile patients with endometriosis. Serum prolactin levels were studied in 43 infertile patients with endometriosis. For controls, 36 infertile patients with normal pelvic findings were used. For standardization, blood samples were drawn on day 21 of the menstrual cycle. Analysis was done by radioimmunoassay using reagent kits. The mean prolactin level in the endometriotic group was 372 mIU/l (range 187-752) while that in the controls was 333 mIU/l.(range 124-767). There was no statistical difference (t = 1.12). Furthermore the accepted normal level for serum prolactin in our population is less than 540 mIU/l. These results show that there is no evidence to implicate raised prolactin levels as a cause for infertility in patients with endometriosis.
Mixed reagents for the Glucose-6-phosphate dehydrogenase (G6PD) deficiency fluorescent screening test were freeze-dried in plastic tubes. The reagents were then reconstituted with distilled water and the test was performed in the usual way. Initial testing with the freeze-dried mixed reagents gave consistent positive reaction to 12 normal blood samples and negative reaction to 9 G6PD deficient blood samples. This will enable a laboratory with freeze-drying facilities to prepare reagent tubes in bulk. As these tubes can be kept at 4 degrees C and do not require to be stored at -20 degrees C, a major laboratory can prepare these tubes and supply small laboratories for screening purposes.
An in-house method which utilizes 14C-thymidine as a substrate was used to assay deoxythymidine kinase in serum. The method is sensitive enough to detect normal levels of serum deoxythymidine kinase and the assay procedure also enables rapid handling of multiple samples. With a total reaction volume of 60 ul, the enzyme reaction was found to be linear with concentrations for up to 650 U/L of TK activity. On studying serum deoxythymidine kinase (s-TK) activity with incubation time, there was a proportional increase in activity with the length of incubation time. "Within-batch" precision showed a coefficient of variation (CV) of 4.7% for serum with extremely high s-TK levels and a CV of 8.8% for serum with normal s-TK levels. S-TK showed a CV of less than 16.0% in its activity when stored at -8 degrees C and at -20 degrees C. The normal reference range obtained for s-TK activity was 8.6 +/- 7.5 U/L.
Seventy-seven patients who had PAP smear cytology and colposcopic examination in a 2-year period between 1988 and 1989 were reviewed. Those with findings indicative or suspicious of malignancy were subjected to biopsy. All 50 patients thus biopsied were confirmed to have preclinical cancer on histological examination. Compared against histology, PAP smear cytology gave an accuracy rate of 90% (5 false negatives) and colposcopy gave an accuracy rate of 94% (3 false negatives). These results demonstrate that the two techniques are useful as screening tests for preclinical cervical cancer. The results are improved if they are used complementarily. However, there was poor specificity in the categorisation of cervical cancer by both methods. This was probably due to the subjectiveness of the two procedures. The study also raised the possibility of a higher incidence of preclinical cervical cancer in the Chinese ethnic group.
An adult male sustained a number of stab injuries and other injuries including a fatal stab injury to the neck. There was evidence of air embolism which was considered to be a major factor causing death. The discussion is in four parts. Part I is confined to the post mortem examination. Part II relates to the medico-legal aspects of the case. Part III is a general discussion on embolism and its medico-legal significance whilst Part IV is on the medico-legal aspects of air embolism.
Immunophenotyping of acute leukaemias has become an important diagnostic tool in haematology laboratories as it is now well recognised that the presence of certain surface markers has prognostic significance. In 1988, we experimented with the alkaline phosphatase anti-alkaline phosphatase (APAAP) method for immunophenotyping of leukaemic cells in our laboratory. 48 cases of peroxidase-negative acute leukaemias were studied. Our study showed that 2 peroxidase-negative cases carried myeloid surface markers, 44% were negative for the markers studied and 5% were unclassified due to technical problems. We concluded that the APAAP method is a useful technique for demonstrating cell markers in leukaemic cells as the reaction is reddish and usually intense. We failed to demonstrate surface markers in 44% of the cases probably because of the choice of a limited panel of monoclonal antibodies.
We investigated microwave-stimulated fixation of tissues for transmission electron microscopy using a domestic microwave oven operating at a frequency of 2.45 GHz with an output power of 500W. Microwave-stimulated fixation, in 4% glutaraldehyde, of fresh rat kidney, liver, heart and brain tissues was compared to conventional fixation. Human renal biopsies were similarly studied. Electron microscopy showed excellent ultrastructural preservation comparable to that obtained by conventional fixation. The optimal temperature range for microwave-stimulated fixation was found to lie between 50 degrees C and 55 degrees C. Our results indicate that microwave-stimulated fixation is a rapid and reproducible technique and can be effectively applied to routine diagnostic pathology.
In the 10-year period from October 1977 to July 1987, 149 cases of primary IgA nephropathy were histologically confirmed through renal biopsies in the Department of Pathology, University Hospital, Kuala Lumpur. The ages of these patients ranged from 5 to 72 years, with the majority in the 20-30 year age group. There was no sex preponderance. The ethnic distribution showed a significant predominance of Chinese with 107 (71.8%) Chinese, 24 (16.1%) Malays, 15 (10.1%) Indians and 3 others. A wide range of renal glomerular pathology was seen, the commonest being diffuse mesangioproliferative glomerulonephritis (59.1%). Focal proliferative glomerulonephritis (14.1%) followed by minimal change glomerulonephritis (10.7%) were next in order of frequency. Immunofluorescence studies consistently demonstrated heavy and predominant IgA deposition in the mesangium. Weak deposition of C3, IgG and IgM were also observed in various combinations.
A simple and sensitive double-antibody radioimmunoassay for human growth hormone (HGH) was developed, optimised and validated. The anti-hGH sera raised in 2 rabbits were highly specific with low cross-reactions of 0.19% and 0.3% with human placental lactogen and 0.21% and 0.13% with human prolactin. The mean sensitivity of the assay determined from 28 assays was found to be 0.4 +/- 0.2 mIU/L. Mean recovery of added exogenous hGH was 98.8 +/- 6.8%. Linearity studies of samples diluted at 1:2, 1:4 and 1:8 gave values of 101.3 +/- 5.3%, 109.6 +/- 13.4% and 97.3 +/- 13% respectively of those expected. The reproducibility of the assay was good; within assay coefficient of variation for serum samples with GH concentrations of 2.7, 13.6 and 28.2 mU/l ranged from 5.1 to 8.3% while the inter-assay precision varied from 4.9 to 10.3%. The in-house assay showed good correlation (r = 0.96, p less than 0.001) with a commercial HGH RIA kit (Dainabot, Japan). A reference normal adult fasting GH level of less than 7 mIU/l was established from 95 samples assayed by this method.
The routine study of bone marrow trephine biopsies involves fixation, decalcification, paraffin-embedment, sectioning and staining. However, this process creates artifacts, produces shrinkage of tissue, consumes time and can result in sections of unsatisfactory cytological quality. It also renders the tissue unsuitable for enzyme-histochemical and immunohistochemical analyses. Frozen section of bone marrow without decalcification was evaluated as an alternative method for the study of bone marrow. This method was found to give sections with comparable cytological quality to that of paraffin-embedment, yielded sections for interpretation within 24 hours, and allowed enzyme-histochemical and immunohistochemical analyses to be applied successfully.
The Contraves Autolyzer 801 is a 20 parameter cell counter that operates on the principle of impedance. This evaluation study found that the within-batch precision for 5 of its parameters--WBC, RBC, Hb, Hct and Plt--had coefficients of variation below 5%, while the counts for red cell parameters were reproducible for up to 3 days. The analyser exhibited good linearity for all the parameters. When compared with 2 other counters--the Coulter S-Plus and the Coulter M350, some degree of proportional and constant bias due to unsuitable calibration were detected in the WBC, Hct and Plt parameters. Otherwise it showed generally good correlation in all the parameters and also with the manual PCV method. Carry over was negligible in the red cell parameters. The Contraves Autolyzer 801 is easy to operate and readily accepted by operators.
The 'Dextran' and the 'Buffy-coat' methods for isolation of human leucocytes for DNA extraction were compared on the basis of DNA yield from the same amounts (10 ml) of blood. Human leucocytes from a total of 11 samples were isolated using both methods for each sample after which DNA was extracted. Extracted DNA samples were treated with ribonucleases and proteinase K after which the yields were quantitated by measuring absorbance at 260 nm. The 'Buffy-coat' method yielded a mean concentration of DNA of 476.7 micrograms/ml (range: 212 to 700 micrograms/ml) while the 'Dextran' method yielded 188.4 micrograms/ml (range: 64 to 340 micrograms/ml). The difference was confirmed by subjecting the extracted DNA samples to agarose gel electrophoresis.