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.
150 specimens from suspected herpes simplex genital and skin lesions were received in virus transport medium. They were inoculated into Hep-2 cell monolayers, examined for the presence of virus by cytopathic effect (CPE), direct immunoperoxidase (DIP) and direct immunofluorescence (DIF). Of 39 (26.0%) virus-positive specimens by CPE, 37 (24.7%) were HSV-positive by DIP and 36 (24.0%) by DIF staining. DIP staining had a sensitivity of 100%, specificity of 99.1%, positive predictive value of 97.3% and negative predictive value of 100% in relation to DIF as a standard test. Of 39 specimens positive by CPE, only 25.6% were HSV-positive within 24 h post-inoculation compared to 94% HSV-positive by DIP and DIF staining at the same time.
The occurrence of MHC class I and class II antigens on four human colonic carcinoma cell lines and the effect of recombinant interferon-gamma (rIFNg) on the expression of these antigens was investigated by immunofluorescent flow cytometry. The concentration of rIFNg which resulted in the largest increase in expression of class I and class II antigens was determined. Changes in the amount of MHC antigen on the membrane were indicated by a shift in the mean fluorescence intensity (MFI) of the cell population. Without addition of rIFNg, the COLO 206, COLO 320F and COLO 397 cell lines were class I positive although the COLO 206 cell line expressed less class I antigen than the other two lines. The HT-29 cell line expressed only a minimal level of class I antigen. Treatment with rIFNg increased the amount of class I antigen on these cell lines 5, 1.4, 2.5 and 20 times respectively. Maximum levels of class I antigen were found two days after treatment. Class I antigen expression returned to pre-treatment levels by day 8 in all but the HT-29 cell line, which maintained its increased level following a single dose of rIFNg. All four cell lines had little or no class II antigens. Following treatment with rIFNg, DR antigen appeared on all four lines whereas DP and DQ antigens could be induced only on the 320F and 397 lines. The amount of class II antigen reached its peak two days after treatment and gradually decreased over the next 6 days of culture.(ABSTRACT TRUNCATED AT 250 WORDS)
We describe the design and management of a 35 mm slide database using a menu-driven dBASE III PLUS programme and a microcomputer in a large department of pathology that also caters for the individual pathologist. Existing systems described in the literature are geared towards slides of general medicine and do not address the needs of the individual pathologist. A total of 11,481 slides in the Department of Pathology, Faculty of Medicine, University of Malaya, were filed into a single database with each record representing one slide. Nine fields which comprised the slide accession number, reference number, slide category, SNOMED codes, and a description of the slide in natural language, seemed adequate for slide definition. The menu-driven programme had functions which included the abilities to add, delete, edit and back-up records, and to search for desired slides. Although slides may be searched for in various fields, we found that searches using natural language alone were both comprehensive and efficient, provided a standard format of description was adhered to and data entries scrutinized carefully for errors. We believe therefore, that for the pathologist working alone, coded language fields are not absolutely necessary, as manual coding and additional data entry can be time consuming. As expected, for databases larger than 10,000 slides, a 80286 microprocessor-based microcomputer was more efficient. We are of the opinion that a system such as ours is very useful for a large department of pathology or the individual pathologist to file and retrieve 35 mm slides.
A retrospective study was made to determine relative incidence of lymphoma subtypes in Malaysia. High grade non-Hodgkin's lymphoma was found to be common. Low grade non-Hodgkin's lymphoma and Hodgkin's disease were relatively rare in this Malaysian series. Non-Hodgkin's lymphoma of B-cell immunophenotype was four times as common as that of T-cell lineage. There was a high incidence of primary extranodal non-Hodgkin's lymphoma.
448 isolates of methicillin-resistant Staphylococcus aureus (MRSA) from clinical specimens of patients from the University Hospital, Kuala Lumpur, were phage-typed. These included 35 strains causing two separate outbreaks of infection, one in surgical Ward 6B and another in the Special Care Nursery (SCN). Antibiograms of these outbreak strains in Ward 6B and SCN were entirely different. Phage-typing revealed that 72% of the MRSA isolates were typable. They were typed entirely by Group III phages, the majority (76%) of which were phage type 85. There was only one isolate in SCN which was typed by Group I (phage 80) and Group III phages. None were typed by phages 94, 95, 96 and Group II phages. 14.6% of the typable isolates gave the long pattern reaction of the phage 6/47/54/75/77/83A/84/85 complex. The majority of the outbreak strains in Ward 6B were of phage type 85, whereas those in the SCN were all of the 6/47/54/75/77/83A/84 phage pattern with the exception of one isolate which was also typed by phage 80, a Group I phage.
Gas-Liquid chromatography (GLC) was used to detect the presence of isocaproic acid produced by Clostridium difficile from 54 stool samples grown in cycloserine-cefoxitin broth. Isocaproic acid was detected in 12 samples of which 5 were confirmed to be Clostridium difficile by culture and biochemical tests. The detection of isocaproic acid by GLC together with the presence of presumptive colonies on primary selective culture media provides a more rapid laboratory diagnosis for Clostridium difficile.
Most methods used in double esterase cytochemistry for the diagnosis and classification of acute myeloid leukaemias require double incubation and staining, using separate coupling reagents. We evaluated a method by Swirsky on our normal and abnormal blood and bone marrow smears where only a single incubation and the use of a single coupling reagent is required. Its short incubation period and its strong positive reaction for butyrate esterase in demonstrating cells of monocytic lineage gives it an advantage over the conventional double incubation technique.
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.
Although most anatomical pathologists have encountered breast lesions with the composite histological features of fibroadenoma (FA) and fibrocystic change (FC), referred to as fibroadenomatosis or fibroadenomatoid mastopathy (FAM), little is known about its prevalence or clinico-pathological significance. In a retrospective histological review of 400 consecutive breast lesions, among both East and West Malaysians, coded either as FA or FC in the files of the Department of Pathology, University of Malaya, we found 45 (11.3%) cases of FAM. Typically, FAM lesions showed fibroadenomatoid foci in a background of fibrocystic change. The finding of FAM among lesions coded as FC was higher (18.5%) than among FA (4%). The mean age of patients with FAM (32.1 years) was similar to FC (35.1 years) but significantly older than that of FA (26.1 years). The notion that FA and FC are lesions at two ends of a spectrum of growth disorder of breast related to oestrogen-progesterone interplay, and that FAM occupies a position intermediate between the two, may explain its morphological and age patterns, but remains speculative. It is hoped that increasing awareness of this condition will lead to better understanding of breast pathophysiology. Nevertheless, until its biological nature, histogenesis and malignant potential are more clearly understood, defining FAM as a distinct form of breast disease may not be meaningful to patient management.
Serum alpha-fetoprotein (AFP) levels and its expression in liver tissue was studied in 50 cases of histologically confirmed hepatocellular carcinoma (HCC). Serum AFP levels were elevated (greater than 20iu/ml) in 35/50 (70%) of the cases, 28 of whom had levels greater than 500 iu/ml, which is highly suggestive of HCC. These results indicate that serum AFP, by itself, is a relatively insensitive diagnostic test for HCC. Although elevated levels in high risk patients provide a specific clue, a negative result does not exclude the diagnosis of HCC. Expression of AFP by tumour cells paralleled that of serum in the majority of cases. However, tissue AFP was negative in 7 patients who had markedly elevated serum AFP. This observation may be a reflection of preferential excretion of the tumour antigen or differential expression of the antigen by the tumour cells. None of the patients with normal serum AFP demonstrated a reaction for tissue AFP. There was no correlation between AFP production and tumour differentiation.
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.