Male-specific coliphages are often used as indicators of contamination by enteric viruses. These phages can be detected in water samples by plaque assays and by polymerase chain reaction. In this study, the M13 coliphage was used to develop a real-time PCR assay for the detection of male-specific DNA coliphages. The real-time PCR was found to have a reaction efficiency of 1.45 and detection limit of 10(-3) plaque forming units per reaction mix. Repeated amplification and melting curve analyses demonstrated high specificity and reproducibility of the real-time assay. Quantitative detection with the real-time PCR should allow rapid assessment of the level of viral contamination in water.
MeSH terms: DNA, Viral/analysis*; Sensitivity and Specificity; Water Microbiology*; Reproducibility of Results; Bacteriophage M13/genetics*; Bacteriophage M13/isolation & purification*; Reverse Transcriptase Polymerase Chain Reaction*
Metastasising ability connotes one of the most important life-threatening properties of malignant neoplasms. Recent studies indicate that CD44 proteins, multifunctional cell adhesion molecules which contribute to "homing" of lymphocytes to lymph nodes as well as cell-cell and cell-matrix interactions, are potential markers of tumour progression. However, whether CD44 expression by human tumours contribute to increased metastatic risk remains controversial. In an attempt to clarify its role in breast cancer, we have investigated the correlation between CD44 expression by breast carcinoma and the presence of axillary lymph node metastases. CD44 expression was detected using a standard immunoperoxidase method on formalin-fixed, paraffin-embedded, primary infiltrating ductal breast carcinoma tissues taken from 60 female patients who underwent mastectomy with axillary node clearance. Tumours were graded according to the modified Bloom and Richardson criteria. 62% of patients had histologically-proven lymph node metastasis. 40% of primary cancers exhibited cytoplasmic membrane immunopositivity for CD44. 46% of primary tumours which have metastasied to axillary lymph nodes were CD44 positive whereas 30% of tumours which have not metastasised expressed CD44. CD44 positivity was expressed by 20% of grade 1, 31% grade 2 and 58% grade 3 tumours. Our results suggest that CD44 may have a role in the progression of breast cancer and emphasise the need to investigate its interaction with other mechanisms of cancer advancement.
Hepatocellular carcinoma (HCC) is the most common primary liver cancer and its diagnosis on routine stains is usually straightforward, except in some cases where there may be difficulty in distinguishing HCCs from metastatic carcinomas (MC) and cholangiocarcinomas (CC). Hepatocyte Paraffin 1 antibody (Hep Par 1) is a new monoclonal antibody which reacts with normal and neoplastic hepatocytes, and this study aims to determine its specificity and sensitivity in distinguishing hepatocellular carcinoma (HCC) from cholangiocarcinoma (CC) and metastatic carcinomas (MC). Hep Par 1 antibody was applied to 28 cases of HCC, 22 cases of MC from varying sites and 8 CCs, and produced a strong, diffuse, granular, cytoplasmic staining of all benign hepatocytes. 23 out of 28 cases of HCC showed heterogeneously positive staining for Hep Par 1 irrespective of their degree of differentiation, while 2 out of 8 cases of cholangiocarcinoma were positive for Hep Par 1, and all 22 cases of metastatic carcinoma were negative. The sensitivity and specificity of Hep Par 1 for HCC was 82.1% and 93.3% respectively; whereby the antibody was noted to show occasional false positivity in cases of cholangiocarcinoma and non-neoplastic bowel mucosa, while its variable staining in HCC produced false negative results in some small biopsies. Thus, Hep Par 1 should be used in a panel with other antibodies to obtain useful information in distinguishing HCC from CC and MC.
MeSH terms: Antibodies, Monoclonal/analysis*; Bile Duct Neoplasms/diagnosis*; Bile Duct Neoplasms/chemistry; Bile Ducts, Intrahepatic/pathology*; Bile Ducts, Intrahepatic/chemistry; Diagnosis, Differential; Carcinoma, Hepatocellular/diagnosis*; Carcinoma, Hepatocellular/chemistry; Humans; Liver Neoplasms/diagnosis*; Liver Neoplasms/secondary; Predictive Value of Tests; Sensitivity and Specificity; Staining and Labeling; Biomarkers, Tumor/analysis; Cholangiocarcinoma/diagnosis*; Cholangiocarcinoma/chemistry; Hepatocytes/pathology; Hepatocytes/chemistry
This study was carried out to determine the role of p53 and p21 in the pathogenesis of prostatic adenocarcinoma and their association with tumour grade.
Survivin is an inhibitor of apoptosis protein and regulates the cell cycle in the G2/M phase. Survivin is expressed during embryonic and fetal development, selectively over-expressed in common human cancers and completely down-regulated in normal adult tissue. This work was aimed at studying the expression of the survivin homologues and their subcellular distribution in fetal and normal adult tissues of rat. Survivin expression was evaluated by immunohistochemistry in formalin-fixed, paraffin-embedded tissue sections of fetal and normal adult tissues of rat using the polyclonal serum SUR12A-CFI. This serum demonstrated intense positive survivin staining in adult kidney, ovary and oviduct, and a variable expression in different fetal organs, with particularly intense expression detected in the adrenal gland, liver, stomach, small intestine, colon, kidney and skin. In both fetal and adult tissues, the expression was predominantly cytoplasmic. It was concluded that survivin was abundantly and prominently expressed during fetal development in rat and that the polyclonal anti-human survivin antibody SUR12A-CFI is reactive with rat survivin.
Paroxysmal nocturnal haemoglobinuria (PNH) is an acquired haemopoietic stem cell disorder arising from somatic mutation of the X-linked PIG-A gene which leads to deficiency of the glycosylphosphatidylinositol (GP1) membrane anchor proteins such as CD 59 (MIRL: membrane inhibitor of reactive lysis) and CD 55 (DAF: decay accelerating factor). Allogeneic peripheral blood stem cell transplant (PBSCT) is a curative mode of treatment in symptomatic PNH patients. Assessment of donor chimerism for PBSCT can be performed by various methods including short tandem repeat loci (STR) and variable number of tandem repeats (VNTR). Flow cytometry, which is much cheaper and faster, also can be used to assess engraftment in patients with PNH. Engrafted patients will show the presence of CD 55 and CD 59 on their red cells and white cells. We describe here the usefulness of flow cytometry in the assessment of donor chimerism following allogeneic PBSCT, in a case of PNH.
We report a case of clear cell "sugar" tumour of the lung (CCTL) occurring in a 26-year-old lady. The patient was asymptomatic and the lesion was picked up in the course of a pre-employment medical examination. A well-defined 5 cm nodule in the right lower lobe was detected on routine chest X-Ray. Microscopical examination of the coin lesion showed clear cells containing abundant diastase-sensitive intracytoplasmic glycogen, as demohstrated with periodic acid-Schiff stains. Tumour immunoreactivity for HMB-45 and non-reactivity for cytokeratin support the histological diagnosis. To our knowledge, this is the first reported case of CCTL in Malaysia.
ABSTRACT Mango malformation disease (MMD) occurs in Asia, Africa, and the Americas and was first reported in India in 1891. The vegetative form of MMD was first reproduced in 1966 with Fusarium moniliforme and the floral form with isolates of F. moniliforme var. subglutinans from both vegetative shoots and floral tissue. The fungi were subsequently recognized as F. subglutinans. In 2002, a new species, F. mangiferae, was established based on nuclear and mitochondrial DNA sequences; it included strains of F. subglutinans from Egypt, Florida, Israel, Malaysia, and South Africa, some of which had been shown to cause MMD by artificial inoculation. At least three additional taxa have been associated with MMD: F. sterilihyphosum from Brazil and South Africa, and Fusarium sp. nov. and F. proliferatum (teleomorph: Gibberella intermedia) from Malaysia. To date, Koch's postulates have not been completed with them. In the future, gene sequencing will be essential to identify the Fusarium spp. that are associated with MMD. Work remains to be done on the morphology, sexual compatibility, pathogenicity, and toxigenicity of these taxa.
An optical biosensor consisting of a chromoionophore (ETH5294) (CM) doped sol-gel film interfaced with another sol-gel film immobilized with acetylcholinesterase (AChE) was employed to detect the insecticide dichlorvos. The main advantage of this optical biosensor is the use of a sol-gel layer with immobilized CM that possesses lipophilic property. The highly lipophilic nature of the CM and its compatibility with the sol-gel matrix has prevented leaching, which is frequently a problem in optical sensor construction based on pH indicator dyes. The immobilization of the indicator and enzyme was simple and need no chemical modification. The CM layer is pH sensitive and detects the pH changes of the acetylcholine chloride (AChCl) substrate when hydrolyzed by AChE layer deposited above. In the absence of the AChE layer, the pH response of the CM layer is linear from pH 6 to 8 (R(2)=0.98, n=3) and it showed no leaching of the lipophilic chromoionophore. When the AChE layer is deposited on top, the optical biosensor responds to AChCl with a linear dynamic range of 40-90mM AChCl (R(2)=0.984, n=6). The response time of the biosensor is 12min. Based on the optimum incubation time of 15min, a linear calibration curve of dichlorvos against the percentage inhibition of AChE was obtained from 0.5 to 7mg/L of dichlorvos (17-85% inhibition, R(2)=0.991, n=9). The detection limit for dichlorvos was 0.5mg/L. The results of the analysis of 1.7-6.0mg/L of dichlorvos using this optical biosensor agreed well with a gas chromatography-mass spectrometry detection method.
The development of an optical biosensor based on immobilization of 3-methyl-2-benzothiazolinone hydrazone (MBTH) in hybrid nafion/sol-gel silicate film and tyrosinase in chitosan film for the detection of phenolic compounds has been described. Tyrosinase was immobilized in chitosan film deposited on the hybrid nafion/sol-gel silicate film containing MBTH. The enzymatic oxidation product of phenolic compounds were stabilized through formation of adduct with MBTH to produce a maroon color adduct. The color intensity of adduct was found to increase proportionally with the increase of the substrate concentrations after 5min exposure. The linearity of the biosensor towards phenol, catechol and m-cresol were in the respective concentration range of 0.5-7.0, 0.5-10.0 and 1.0-13.0mg/L with detection limit of 0.18, 0.23 and 0.43mg/L, respectively. The biosensor shows a good stability for at least 3 months.
This paper analyses the experience of one individual in the development and delivery of an innovative, undergraduate leadership development module. The module is accessed by practising health care professionals in Malaysia as part of a top-up Honours Degree and is delivered solely using a virtual learning environment (VLE), in this case Blackboard. The aim of this analysis is to contribute to the current body of knowledge regarding the use of VLE technology to facilitate learning at a distance. Of particular relevance is the paper's focus on: the drivers for e-learning; widening participation and increasing access; the experience of designing and delivering learning of relevance for this contemporary student population and evaluating the VLE experience/module. The development and delivery of this module is one result of a rapidly growing area of education. As a novice teacher in her first year in the higher education sector, this experience was a significant and stimulating challenge for a number of reasons and these are explored in greater depth. This is achieved by means of personal reflection using the phases of module development and delivery as a focus.