Displaying publications 41 - 60 of 179 in total

Abstract:
Sort:
  1. Do clinical features and survival of single hormone receptor positive breast cancers differ from double hormone receptor positive breast cancers?
    Ng CH, Pathy NB, Taib NA, Ho GF, Mun KS, Rhodes A, et al.
    Asian Pac J Cancer Prev, 2014;15(18):7959-64.
    PMID: 25292095
    The significance of the single hormone receptor positive phenotype of breast cancer is still poorly understood. The use of hormone therapy has been found to be less effective for this type, which has a survival outcome midway between double positive and double negative phenotypes. The aim of this study was to investigate differences in patient and tumor characteristics and survival between double-receptor positive (ER+PR+), double receptor negative (ER-PR-) and single receptor positive (ER+PR- and ER-PR+) breast cancer in an Asian setting. A total of 1,992 patients with newly diagnosed stage I to IV breast cancer between 2003 and 2008, and where information on ER and PR were available, were included in this study. The majority of patients had ER+PR+ tumors (n=903: 45.3%), followed by 741 (37.2%) ER-PR-, 247 (12.4%) ER+PR-, and 101 (5.1%) ER-PR+ tumors. Using multivariate analysis, ER+PR- tumors were 2.4 times more likely to be grade 3 compared to ER+PR+ tumors. ER+PR- and ER-PR+ tumors were 82% and 86% respectively less likely to be grade 3 compared with ER-PR- tumors. ER-PR+ tumours were associated with younger age. There were no survival differences between patients with ER+PR+ and ER-PR+ tumors. However, ER+PR- tumors have poorer survival compared with ER+PR+ tumours. ER-PR- tumours had the worst survival. Adjuvant hormonal therapy with tamoxifen was found to have identical survival advantage in patients with ER+PR+ and ER-PR+ tumors whereas impact was slightly lower in patients with ER+PR- tumors. In conclusion, we found ER+PR- tumors to be more aggressive and have poorer survival when compared to ER+PR+ tumors, while patients with ER-PR+ tumours were younger, but had a similar survival to their counterparts with ER+PR+ tumours.
  2. CD44s expression correlated with the International Neuroblastoma Pathology Classification (Shimada system) for neuroblastic tumours
    Munchar MJ, Sharifah NA, Jamal R, Looi LM
    Pathology, 2003 Apr;35(2):125-9.
    PMID: 12745459
    CD44 is a cell adhesion molecule that plays an important role in the cascade of metastasis and progression of human malignant tumours. A large family of variants or isoforms, generated by alternative splicing of a single gene, has been reported to be involved in the malignant process by conferring metastatic potential to non-metastatic cells. The objective of this study was to compare the expression of CD44 standard molecule with the International Neuroblastoma Pathology Classification (INPC) for neuroblastic tumours, a histological grading system based on the Shimada system for predicting the clinical outcome in neuroblastic tumours.
  3. Fulltext Proliferating cell nuclear antigen (PCNA) activity in hepatocellular carcinoma, benign peri-neoplastic and normal liver
    Mun KS, Cheah PL, Baharudin NB, Looi LM
    Malays J Pathol, 2006 Dec;28(2):73-7.
    PMID: 18376794 MyJurnal
    Hepatocellular carcinoma (HCC) is among the ten most common cancers in Malaysian males. As cellular proliferation is an important feature of malignant transformation, we studied the proliferation pattern of normal and benign perineoplastic liver versus hepatocellular carcinoma in an attempt to further understand the tumour transformation process. 39 HCC (21 with accompanying and 18 without cirrhosis) histologically diagnosed at the Department of Pathology, University of Malaya Medical Centre between January 1992 and December 2003 were immunohistochemically studied using a monoclonal antibody to PCNA (Clone PC10: Dako). 20 livers from cases who had succumbed to traumatic injuries served as normal liver controls (NL). PCNA labeling index (PCNA-LI) was determined by counting the number of immunopositive cells in 1000 contiguous HCC, benign cirrhotic perineoplastic liver (BLC), benign perineoplastic non-cirrhotic (BLNC) and NL cells and conversion to a percentage. The PCNA-LI was also expressed as Ojanguren et al's grades. PCNA was expressed in 10% NL, 38.9% BLNC, 76.2% BLC and 71.8% HCC with BLNC, BLC and HCC showing significantly increased (p < 0.05) number of cases which expressed PCNA compared with NL. The number of BLC which expressed PCNA was also significantly increased compared with BLNC. PCNA-LI ranged from 0-2.0% (mean = 0.2%) in NL, 0-2.0% (mean = 0.3%) in BLNC, 0-3.6% (mean = 0.7%) in BLC and 0-53.8% (mean = 7.6%) in HCC with PCNA-LI significantly increased (p < 0.05) only in HCC compared with BLC, BLNC and NL. Accordingly, all NL, BLC and BLNC showed minimal (<5% cells being immunopositive) immunoreactivity on Ojanguren et al's grading system and only HCC demonstrated immunoreactivity which ranged up to grade 3 (75% of cells). From this study, there appears to be a generally increasing trend of proliferative activity from NL to BLNC to BLC and HCC. Nonetheless, BLNC and BLC, like NL, retained low PCNA-LI and only HCC had a significantly increased PCNA-LI compared with the benign categories. This is probably related to the malignant nature of HCC and may reflect the uncontrolled proliferation of the neoplastic hepatocytes.
  4. Fulltext Structural Studies of Epithelial Mesenchymal Transition Breast Tissues
    Mohd Sobri SN, Abdul Sani SF, Sabtu SN, Looi LM, Chiew SF, Pathmanathan D, et al.
    Sci Rep, 2020 02 06;10(1):1997.
    PMID: 32029810 DOI: 10.1038/s41598-020-58932-5
    At the supramolecular level, the proliferation of invasive ductal carcinoma through breast tissue is beyond the range of standard histopathology identification. Using synchrotron small angle x-ray scattering (SAXS) techniques, determining nanometer scale structural changes in breast tissue has been demonstrated to allow discrimination between different tissue types. From a total of 22 patients undergoing symptomatic investigations, different category breast tissue samples were obtained in use of surgically removed tissue, including non-lesional, benign and malignant tumour. Structural components of the tissues were examined at momentum transfer values between q = 0.2 nm-1 and 1.5 nm-1. From the SAXS patterns, axial d-spacing and diffuse scattering intensity were observed to provide the greatest discrimination between the various tissue types, specifically in regard to the epithelial mesenchymal transition (EMT) structural component in malignant tissue. In non-lesional tissue the axial period of collagen is within the range 63.6-63.7 nm (formalin fixed paraffin embedded (FFPE) dewaxed) and 63.4 (formalin fixed), being 0.9 nm smaller than in EMT cancer-invaded regions. The overall intensity of scattering from cancerous regions is a degree of magnitude greater in cancer-invaded regions. Present work has found that the d-spacing of the EMT positive breast cancer tissue (FFPE (dewaxed)) is within the range 64.5-64.7 nm corresponding to the 9th and 10th order peaks. Of particular note in regard to formalin fixation of samples is that no alteration is observed to occur in the relative differences in collagen d-spacing between non-lesional and malignant tissues. This is a matter of great importance given that preserved-sample and also retrospective study of samples is greatly facilitated by formalin fixation. Present results indicate that as aids in tissue diagnosis SAXS is capable of distinguishing areas of invasion by disease as well as delivering further information at the supramolecular level.
  5. A review: Exploring the metabolic and structural characterisation of beta pleated amyloid fibril in human tissue using Raman spectrometry and SAXS
    Mohd Nor Ihsan NS, Abdul Sani SF, Looi LM, Cheah PL, Chiew SF, Pathmanathan D, et al.
    Prog Biophys Mol Biol, 2023 Sep;182:59-74.
    PMID: 37307955 DOI: 10.1016/j.pbiomolbio.2023.06.002
    Amyloidosis is a deleterious condition caused by abnormal amyloid fibril build-up in living tissues. To date, 42 proteins that are linked to amyloid fibrils have been discovered. Amyloid fibril structure variation can affect the severity, progression rate, or clinical symptoms of amyloidosis. Since amyloid fibril build-up is the primary pathological basis for various neurodegenerative illnesses, characterization of these deadly proteins, particularly utilising optical techniques have been a focus. Spectroscopy techniques provide significant non-invasive platforms for the investigation of the structure and conformation of amyloid fibrils, offering a wide spectrum of analyses ranging from nanometric to micrometric size scales. Even though this area of study has been intensively explored, there still remain aspects of amyloid fibrillization that are not fully known, a matter hindering progress in treating and curing amyloidosis. This review aims to provide recent updates and comprehensive information on optical techniques for metabolic and proteomic characterization of β-pleated amyloid fibrils found in human tissue with thorough literature analysis of publications. Raman spectroscopy and SAXS are well established experimental methods for study of structural properties of biomaterials. With suitable models, they offer extended information for valid proteomic analysis under physiologically relevant conditions. This review points to evidence that despite limitations, these techniques are able to provide for the necessary output and proteomics indication in order to extrapolate the aetiology of amyloid fibrils for reliable diagnostic purposes. Our metabolic database may also contribute to elucidating the nature and function of the amyloid proteome in development and clearance of amyloid diseases.
  6. EDXRF and the relative presence of K, Ca, Fe and as in amyloidogenic tissues
    Mohd Nor Ihsan NS, Abdul Sani SF, Looi LM, Pathmanathan D, Cheah PL, Chiew SF, et al.
    Spectrochim Acta A Mol Biomol Spectrosc, 2024 Mar 05;308:123743.
    PMID: 38113556 DOI: 10.1016/j.saa.2023.123743
    Trace and minor elements play crucial roles in a variety of biological processes, including amyloid fibrils formation. Mechanisms include activation or inhibition of enzymatic reactions, competition between elements and metal proteins for binding positions, also changes to the permeability of cellular membranes. These may influence carcinogenic processes, with trace and minor element concentrations in normal and amyloid tissues potentially aiding in cancer diagnosis and etiology. With the analytical capability of the spectroscopic technique X-ray fluorescence (XRF), this can be used to detect and quantify the presence of elements in amyloid characterization, two of the trace elements known to be associated with amyloid fibrils. In present work, involving samples from a total of 22 subjects, samples of normal and amyloid-containing tissues of heart, kidney, thyroid, and other tissue organs were obtained, analyzed via energy-dispersive X-ray fluorescence (EDXRF). The elemental distribution of potassium (K), calcium (Ca), arsenic (As), and iron (Fe) was examined in both normal and amyloidogenic tissues using perpetual thin slices. In amyloidogenic tissues the levels of K, Ca, and Fe were found to be less than in corresponding normal tissues. Moreover, the presence of As was only observed in amyloidogenic samples; in a few cases in which there was an absence of As, amyloid samples were found to contain Fe. Analysis of arsenic in amyloid plaques has previously been difficult, often producing contradictory results. Using the present EDXRF facility we could distinguish between amyloidogenic and normal samples, with potential correlations in respect of the presence or concentration of specific elements.
  7. Fulltext Tuberculosis or systemic lupus erythematosus? A diagnostic and therapeutic dilemma
    Mohd A, Goh EM, Chow SK, Looi LM, Yeap SS
    Southeast Asian J. Trop. Med. Public Health, 2003 Jun;34(2):361-4.
    PMID: 12971563
    The diagnosis of patients with fever of unknown origin (FUO) is often problematic because the range of possible differential diagnoses is broad. We report on a case in which a patient presented with FUO and was subsequently found to have both a collagen vascular disease and an intercurrent infection. Treatment for the collagen vascular disease with corticosteroids exacerbated the intercurrent infection. The problems in the diagnosis and management of such cases are discussed.
  8. Cyclooxygenase-2 expression in invasive breast carcinomas of no special type and correlation with pathological profiles suggest a role in tumorigenesis rather than cancer progression
    Misron NA, Looi LM, Nik Mustapha NR
    Asian Pac J Cancer Prev, 2015;16(4):1553-8.
    PMID: 25743830
    BACKGROUND: COX-2 has been shown to play an important role in the development of breast cancer and increased expression has been mooted as a poor prognostic factor. The purpose of this study was to investigate the relationship between COX-2 immunohistochemical expression and known predictive and prognostic factors in breast cancer in a routine diagnostic histopathology setting.

    MATERIALS AND METHODS: Formalin-fixed paraffin- embedded tumour tissue of 144 no special type (NST) invasive breast carcinomas histologically diagnosed between January 2009 and December 2012 in Hospital Sultanah Bahiyah, Alor Setar, Kedah were immunostained with COX-2 antibody. COX-2 overexpression was analysed against demographic data, hormone receptor status, HER2- neu overexpression, histological grade, tumour size and lymph node status.

    RESULTS: COX-2 was overexpressed in 108/144 (75%) tumours and was significantly more prevalent (87%) in hormone receptor-positive tumours. There was no correlation between COX-2 overexpression and HER2/neu status. Triple negative cancers had the lowest prevalence (46%) (p<0.05). A rising trend of COX-2 overexpression with increasing age was observed. There was a significant inverse relationship with tumour grade (p<0.05), prevalences being 94%, 83% and 66% in grades 1, 2 and 3 tumours, respectively. A higher prevalence of COX-2 overexpression in smaller size tumours was observed but this did not reach statistical significance. There was no relationship between COX-2 expression and lymph node status.

    CONCLUSIONS: This study did not support the generally held notion that COX-2 overexpression is linked to poor prognosis, rather supporting a role in tumorigenesis. Larger scale studies with outcome data and basic studies on cancer pathogenetic pathways will be required to cast further light on whether COX-2 inhibitors would have clinical utility in cancer prevention or blockage of cancer progression. In either setting, the pathological assessment for COX-2 overexpression in breast cancers would have an important role in the selection of cancer patients for personalized therapy with COX-2 inhibitors.

  9. Cyclooxygenase-2 (COX2) expression in adenocarcinoma surpasses that of squamous cell carcinoma in the uterine cervix
    Marutha Muthu AK, Cheah PL, Koh CC, Chew MF, Toh YF, Looi LM
    Malays J Pathol, 2017 Dec;39(3):251-255.
    PMID: 29279587 MyJurnal
    Over the years, adenocarcinoma (ADC), which has a worse prognosis than squamous cell carcinoma (SCC) of the cervix, has shown an increasing trend. Cyclooxygenase-2 (COX2) expression which has been associated with worse prognosis in several solid cancers was studied for its association with SCC and ADC of the cervix. 35 histologically re-confirmed SCC and 35 ADC were immunohistochemically stained for COX2 using a mouse monoclonal antibody to COX2 (1:100; Dako: Clone CX-294) on a Ventana Benchmark XT. The histoscore was computed as intensity of staining, semi-quantitated on a scale of 0-3 with 0 = negative, 1 = weak, 2 = moderate and 3 = strong staining intensity; multiplied by percentage of immunopositivity on a scale of 0-4 with 0 = <1%, 1 = 1-25%, 2 = 26-50%, 3 = 51-75% and 4 = ≥75% of immunopositive tumour cells. Histoscore 1-3/12 was considered as low and ≥4/12 as high COX2 expression. SCC affected Chinese more than Malays, while Malays had more ADC (p = 0.032). Mean age at presentation of SCC (57.5 years) was about a decade later than ADC at 47.9 years (p = 0.002). 30/35 (85.7%) of SCC and 34/35 (97.1%) of ADC expressed COX2. Histoscores of ADC (median = 4.0, IQR = 3.0-6.0) was significantly higher (p = 0.014) than those of SCC (median = 3.0, IQR = 2.0-3.0). High histoscores (≥4/12) were more frequent in ADC (55.9%) compared with SCC (26.7%) (p = 0.018), implicating COX2, either directly or indirectly, as a possible player in influencing the poorer outcome of ADC compared with SCC.
  10. Fulltext Scientific misconduct encountered by APAME journals: an online survey
    Looi LM, Wong LX, Koh CC
    Malays J Pathol, 2015 Dec;37(3):213-8.
    PMID: 26712665 MyJurnal
    In June 2015, invitations were sent by email to 151 APAME journals to participate in an online survey with an objective of gaining insight into the common publication misconduct encountered by APAME editors. The survey, conducted through SurveyMonkey over a 20-day-period, comprised 10 questions with expansions to allow anecdotes limited to 400 characters, estimated to take less than 10 minutes to complete. Only one invitation was issued per journal, targeting (in order of priority) editors, editorial board members and editorial staff, and limited by email availability. 54 (36%) journals responded. 98% of respondents held Editor or Editorial Board positions. All respondent journals have editorial policies on publication ethics and 96% provide instructions related to ethics. 45% use anti-plagiarism software to screen manuscripts, the most popular being iThenticate, CrossCheck and Turnitin. Up to 50% of journals had encountered studies without IRB approval. Author misconduct encountered were (in rank order): plagiarism (75%), duplicate publication (58%), unjustified authorship (39%), authorship disputes (33%), data falsification (29%), data/image manipulation (27%), conflict of interest (25%), copyright violation (17%) and breach of confidentiality (10%). Reviewer misconduct encountered were: conflict of interest (19%), plagiarism (17%), obstructive behavior (17%), abusive language (13%) and breach of confidentiality (13%). Notwithstanding the limitations of the survey and the response rate, a few insights have been gained: (1) the need for strengthening the ethical culture of researchers/authors and reviewers, (2) anti-plagiarism software can improve plagiarism detection by about 15%, and (3) the need for technical support to detect plagiarism, duplicate publication and image manipulation.
  11. Hearing loss: a global health issue
    Looi LM, Ganten D, McGrath PF, Gross M, Griffin GE
    Lancet, 2015 Mar 14;385(9972):943-4.
    PMID: 25743174 DOI: 10.1016/S0140-6736(15)60208-2
  12. Fulltext The Malaysian Journal of Pathology - moving forward
    Looi LM
    Malays J Pathol, 2014 Apr;36(1):1.
    PMID: 24763229
  13. Food for thought: chocolate
    Looi LM
    Malays J Pathol, 2013 Dec;35(2):109.
    PMID: 24362473
  14. Comparison of telomere length and telomerase activation between breast fibroadenoma and infiltrating ductal carcinoma in Malaysian women
    Looi LM, Cheah PL, Ng MH, Yip CH, Mun KS, Rahman NA
    Asian Pac J Cancer Prev, 2010;11(3):713-6.
    PMID: 21039041
    A study was initiated to explore possible differences in handling telomere attrition in the most common lignant and benign tumours of the breast in Malaysian women. Infiltrating ductal carcinoma (IDC) and fibroadenoma (FA) represented the malignant and benign prototypes respectively. 29 IDC, 28 FA and 22 benign non-lesional control (BNL) breast tissue samples were analysed for telomerase activation using a Telomerase PCR ELISA kit (Boehringer Mannheim). In addition, 23 IDC, 12 FA and 14 BNL were subjected to telomere length determination with a TeloTAGGG Telomere Length Assay Kit (Roche Diagnostic GmbH, Germany), following digestion of genomic DNA by frequently cutting restriction enzymes RsaI and HinfI. Mean telomerase activity in IDC (A450nm=0.3338), but not FA (A450nm=0.0003) was significantly raised (p<0.05) compared with BNL (A450nm=0.0031). Similarly IDC (1.2 kb), but not FA (2.2 kb), showed significant telomere shortening (p<0.05) relative to BNL (2.9 kb). The findings imply that telomere attrition and telomerase activation differ between malignant and benign tumours of the breast and may be important for targeted therapy.
  15. Fulltext Historical development of the renal histopathology services in Malaysia
    Looi LM, Cheah PL
    Malays J Pathol, 2009 Jun;31(1):11-6.
    PMID: 19694308 MyJurnal
    Western-style medicine was introduced to Malaya by the Portuguese, Dutch and British between the 1500s and 1800s. Although the earliest pathology laboratories were developed within hospitals towards the end of the 19th Century, histopathology emerged much later than the biochemistry and bacteriology services. The University Departments of Pathology were the pioneers of the renal histopathology diagnostic services. The Department of Pathology, University of Malaya (UM) received its first renal biopsy on 19 May 1968. Hospital Universiti Kebangsaan Malaysia (HUKM) and Hospital Universiti Sains Malaysia (HUSM) started their services in 1979 and 1987 respectively. It is notable that the early services in these University centres caterred for both the university hospitals and the Ministry of Health (MOH) until the mid-1990s when MOH began to develop its own services, pivoted on renal pathologists trained through Fellowship programmes. Currently, key centres in the MOH are Kuala Lumpur Hospital, Sultanah Aminah Hospital Johor Bahru and Malacca Hospital. With the inclusion of renal biopsy interpretation in the Master of Pathology programmes, basic renal histopathology services became widely available throughout the country from 2000. This subsequently filtered out to the private sector as more histopathologists embraced private practice. There is now active continuing professional development in renal histopathology through clinicopathological dicussions, seminars and workshops. Renal research on amyloid nephropathy, minimal change disease, IgA nephropathy, fibrillary glomerulonephritis, lupus nephritis and microwave technology have provided an insight into the patterns of renal pathology and changing criteria for biopsy. More recently, there has been increasing involvement of renal teams in clinical trials, particularly for lupus nephritis and renal transplant modulation.
  16. Fulltext The Pathology Laboratory Act 2007 explained
    Looi LM
    Malays J Pathol, 2008 Jun;30(1):1-10.
    PMID: 19108405 MyJurnal
    The past century has seen tremendous changes in the scope and practice of pathology laboratories in tandem with the development of the medical services in Malaysia. Major progress was made in the areas of training and specialization of pathologists and laboratory technical staff. Today the pathology laboratory services have entered the International arena, and are propelled along the wave of globalization. Many new challenges have emerged as have new players in the field. Landmark developments over the past decade include the establishment of national quality assurance programmes, the mushrooming of private pathology laboratories, the establishment of a National Accreditation Standard for medical testing laboratories based on ISO 15189, and the passing of the Pathology Laboratory Act in Parliament in mid-2007. The Pathology Laboratory Act 2007 seeks to ensure that the pathology laboratory is accountable to the public, meets required standards of practice, participates in Quality Assurance programmes, is run by qualified staff, complies with safety requirements and is subject to continuous audit. The Act is applicable to all private laboratories (stand alone or hospital) and laboratories in statutory bodies (Universities, foundations). It is not applicable to public laboratories (established and operated by the government) and side-room laboratories established in clinics of registered medical or dental practitioners for their own patients (tests as in the First and Second Schedules respectively). Tests of the Third Schedule (home test blood glucose, urine glucose, urine pregnancy test) are also exempted. The Act has 13 Parts and provides for control of the pathology laboratory through approval (to establish and maintain) and licensing (to operate or provide). The approval or license may only be issued to a sole proprietor, partnership or body corporate, and then only if the entity includes a registered medical practitioner. Details of personnel qualifications and laboratory practices are left to be specified by the Director-General of Health, providing for a formal recognition process and room for revision as pathology practices evolve. Encompassed in the responsibilities of the licensee is the requirement that samples are received and results issued through, and management vested in, a registered medical or dental practitioner. This effectively prohibits "walk-ins" to the laboratory and indiscriminate public screening. The requirement for a person-in-charge in accordance with class and speciality of laboratory ensures that the laboratory is under the charge of the pathology profession. Examined carefully, the requirements of the Act are similar to laboratory accreditation, but are backed by legislation. Many of these details will be spelt out in the Regulations, and these in turn are likely to fall back on National professional guidelines, as accreditation does. Although not at first obvious, enforcement of the Act is based on self-regulation by pathology laboratory professionals. Sincere professional input is thus required to embrace its philosophy, ensure rational and transparent enforcement of legislation, and develop National guidelines for good pathology practices upon which enforcement may be based.
  17. Fulltext Lessons from the Nipah virus outbreak in Malaysia
    Looi LM, Chua KB
    Malays J Pathol, 2007 Dec;29(2):63-7.
    PMID: 19108397 MyJurnal
    The Nipah virus outbreak in Malaysia (September 1998 to May 1999) resulted in 265 cases of acute encephalitis with 105 deaths, and near collapse of the billion-dollar pig-farming industry. Because it was initially attributed to Japanese encephalitis, early control measures were ineffective, and the outbreak spread to other parts of Malaysia and nearby Singapore. The isolation of the novel aetiological agent, the Nipah virus (NiV), from the cerebrospinal fluid of an outbreak victim was the turning point which led to outbreak control 2 months later. Together with the Hendra virus, NiV is now recognised as a new genus, Henipavirus (Hendra + Nipah), in the Paramyxoviridae family. Efforts of the local and international scientific community have since elucidated the epidemiology, clinico-pathophysiology and pathogenesis of this new disease. Humans contracted the infection from close contact with infected pigs, and formed the basis for pig-culling that eventually stopped the outbreak. NiV targeted medium-sized and small blood vessels resulting in endothelial multinucleated syncytia and fibrinoid necrosis. Autopsies revealed disseminated cerebral microinfarctions resulting from vasculitis-induced thrombosis and direct neuronal involvement. The discovery of NiV in the urine and saliva of Malaysian Island flying foxes (Pteropus hypomelanus and Petropus vampyrus) implicated these as natural reservoir hosts of NiV. It is probable that initial transmission of NiV from bats to pigs occurred in late 1997/early 1998 through contamination of pig swill by bat excretions, as a result of migration of these forest fruitbats to cultivated orchards and pig-farms, driven by fruiting failure of forest trees during the El Nino-related drought and anthropogenic fires in Indonesia in 1997-1998. This outbreak emphasizes the need for sharing information of any unusual illnesses in animals and humans, an open-minded approach and close collaboration and co-ordination between the medical profession, veterinarians and wildlife specialists in the investigation of such illnesses. Environmental mismanagement (such as deforestation and haze) has far-reaching effects, including encroachment of wildlife into human habitats and the introduction of zoonotic infections into domestic animals and humans.
  18. Fulltext CD44 expression and axillary lymph node metastasis in infiltrating ductal carcinoma of the breast
    Looi LM, Cheah PL, Zhao W, Ng MH, Yip CH
    Malays J Pathol, 2006 Dec;28(2):83-6.
    PMID: 18376796 MyJurnal
    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.
  19. Fulltext Telomerase activation in neoplastic cell immortalization and tumour progression
    Looi LM, Ng MH, Cheah PL
    Malays J Pathol, 2007 Jun;29(1):33-5.
    PMID: 19105326 MyJurnal
    The unique ability of tumour cells to proliferate indefinitely is crucial to neoplastic progression as it allows these cells to express the aggressive properties of cancer without the censure of physiological ageing. This is in contrast to normal somatic cells which are subject to a "mitotic clock," a phenomenon that has been linked to telomeric shortening after each round of cell replication, so that eventually the loss of genetic material reaches a critical stage and the cells undergo senescence and cell death. A study was conducted to investigate the role of telomerase, an RNA-containing enzyme that restores the telomere length, in the neoplastic cell immortalization and progression process. Fresh human tissue samples taken from excision specimens received by the Department of Pathology, University of Malaya Medical Centre, were investigated for telomerase activity using a commercial Telomerase PCR-ELISA kit (Boehringer Mannheim). Specimens comprised 33 breast lesions (10 infiltrating breast adenocarcinoma, 13 fibroadenoma and 10 non-neoplastic breast tissue), 27 colonic lesions (17 colonic adenocarcinoma and 10 non-neoplastic colonic mucosa) and 42 cervical lesions (20 cervical carcinoma and 22 non-neoplastic cervical tissues). Telomerase activity was found in 6 (60%) of 10 breast carcinomas, 6 (46%) of 13 fibroadenomas, none of the 10 nonneoplastic breast samples, 3 (17.6%) of 17 colon carcinomas and none of the 10 non-neoplastic colonic mucosal samples, 12 (60%) of 20 cervical carcinoma and 3 (13.6%) of 22 non-neoplastic cervical samples. 5/10 (50%) Stage I, 4/7 (57%) Stage II, 2/2 (100%) Stage III and 1/1 (100%) Stage IV cervical carcinomas showed telomerase activity. These findings support a contributory role for telomerase in tumourigenesis with activation occurring from neoplastic transformation and increasing with tumour progression.
  20. Microwave-stimulated formaldehyde fixation of experimental renal biopsy tissues: computerised morphometric analysis of distortion artefacts
    Looi LM, Loh KC
    Malays J Pathol, 2005 Jun;27(1):23-7.
    PMID: 16676689
    Although microwave irradiation has been used in the histopathology laboratory for several years, there has been minimal published experimental data on its effects on the technical and staining quality of histological sections. Furthermore, it has not been clear whether the advantages gained in reduction of fixation and staining duration has been at the expense of increasing architectural distortion to the tissues. We report here our experience with computerised morphometric analysis to investigate glomerular artifacts caused by microwave-stimulated fixation of renal tissues. 39 rat and 33 human autopsy kidney samples were subjected to (1) fixation in neutral buffered formaldehyde (control), (2) microwave-stimulated fixation followed by neutral buffered formaldehyde, and (3) neutral buffered formaldehyde followed by microwave irradiation. In addition, the effect of post-fixation in 70% ethanol was also investigated. Microwave irradiation was delivered through a dedicated laboratory microwave oven at 80% power and at 55 degrees C for 3 minutes. The different fixation methods were compared with regards to shrinkage (distortion) to glomerular structures (glomeruli and Bowman's spaces) on H and E sections, as determined by morphometric image analysis using a temporary assembled-system consisting of a trinocular microscope, a digital video camera and personal computer. A FlashPoint VGA 3.3 film-grabber card was used to capture images for morphometric analysis by using a Scion Image program. Morphometric analysis of glomerular structures showed that microwaves caused more shrinkage to the area bounded by the Bowman's capsule than the glomerulus proper, but post-fixation with ethanol reduced this shrinkage. These findings have implications on the logistics of tissue preparation of renal biopsies in clinical practice.
Related Terms
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links