Malaysian Journal of Pathology最新文献

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Lymphomas are a diverse group of malignant proliferations that arise as discrete tissue masses. The most widely accepted taxonomy for lymphoma is the World Health Organization classification of tumours of haematopoietic and lymphoid tissues, the 5th edition of which was released in June 2022. Most (85% to 90%) lymphoid neoplasms are of B cell origin. Mature B-cell neoplasms are a heterogeneous group of malignancies with similar disease courses and treatment paradigms. This review focuses on the various mature B-cell lymphomas in Malaysia, including Hodgkin lymphoma. A literature search was performed in various bibliographic databases. A total of 64 papers were included in this review. We found 15 papers on Hodgkin lymphoma, 14 on follicular lymphoma, 12 on Burkitt lymphoma, 5 on mucosa-associated lymphoid tissue (MALT) lymphoma, 4 on plasmablastic lymphoma, 3 on mantle cell lymphoma, 1 each on primary mediastinal large B-cell lymphoma, B-lymphoblastic lymphoma, and 3 on other unspecified B-cell lymphomas. The site, age, distribution, prognostic markers, and the various subclassification of B cell lymphomas were studied from these papers. Prognostic genetic markers in B-cell lymphomas include C-MYC, BCL2 and BCL6 as they are the most prevalent mutations in this condition. Anecdotal outcomes range from rapid fatality to unexplained spontaneous remission. This review adds to the existing literature on lymphoma in Malaysia by compiling the evidence that may lead to further research on the diagnosis and treatment of lymphoma in Malaysia and worldwide.

Invasive aspergillosis is the second most common invasive human mycosis but susceptibility data of Aspergillus species is limited. Antifungal treatment of aspergillosis is often done empirically without knowing the true susceptibility. Therefore, we aimed to determine antifungal susceptibility of Aspergillus species isolated from various clinical specimens over a 1-year period. We identified 28 Aspergillus isolates by sequencing the internal transcribed spacer (ITS) and β-tubulin genes and performed antifungal susceptibility testing on these isolates using Sensititre YeastOne. The isolates were identified as Aspergillus niger (60.7%), A. fumigatus (21.4%), A. flavus (10.7%), A. chevalieri (3.6%) and A. tubingensis (3.6%). Based on the European Committee on Antimicrobial Susceptibility Testing (EUCAST) Antifungal Clinical Breakpoint for Aspergillus spp., 16/17 (94.1%) A. niger isolates were susceptible to amphotericin B, all six isolates (100%) of A. fumigatus were susceptible to amphotericin B, itraconazole and voriconazole, but only 5/6 (83.3%) A. fumigatus were susceptible to posaconazole. Meanwhile, all three (100%) A. flavus isolates were susceptible to itraconazole. There are no other breakpoints established by the EUCAST for other antifungal-species combinations. In conclusions, Aspergillus niger remains the most commonly isolated species from clinical specimens and Aspergillus isolates at our centre are still largely susceptible to amphotericin B, echinocandins and most azoles. This information is valuable in guiding antifungal therapy in the treatment of aspergillosis.

Borderline oxacillin-resistant Staphylococcus aureus (BORSA) are mecA-negative strains with oxacillin minimum inhibitor concentration (MIC) close to the resistance breakpoint of ≥ 4μg/mL. Instead of producing penicillin-binding protein with low affinity to methicillin (oxacillin) mediated by mecA gene as in methicillin-resistant S. aureus (MRSA), BORSA strains are characterised by the hyperproduction of β-lactamase enzymes, thus able to break down methicillin. Common laboratory methods to detect MRSA such as cefoxitin disk diffusion alone may fail to detect methicillin resistance due to BORSA. We report five cases of BORSA blood-stream infections in a university teaching hospital. All isolates were found to be susceptible to cefoxitin using disk diffusion, resistant to oxacillin using automated MIC method, and did not harbour mecA gene. All patients were suscessfully treated with anti-MRSA antibiotics, and removal of primary sources were done if identified. A more cost-effective method for screening and diagnosis of BORSA is needed in addition to cefoxitin disk diffusion test, in order to monitor the spread, and to enable routine detection and treatment of this pathogen.

Introduction: Persistently elevated thyroid stimulating hormone (TSH) despite levothyroxine (LT4) treatment that exceeds the standard weight-adjusted dose is a common clinical presentation. This may lead to additional testing for LT4 malabsorption or poor LT4 adherence, the latter of which is challenging to confirm because it is predicated on accurate patient accountability.

Case report: A 35-year-old lady, post-radioactive iodine therapy for Graves' disease remained euthyroid for a year on oral LT4. Two years later, she was clinically and biochemically hypothyroid despite claiming LT4 compliance. As all laboratory investigations were within the reference range, pseudomalabsorption was suspected and a LT4 absorption test was done. During the test, her free thyroxine increased significantly at 4 hours, reaching a peak of more than 50% from baseline while TSH decreased appropriately from 0 minute to 360 minutes. This was followed by normalisation of TSH with LT4 treatment under direct observation.

Discussion: The LT4 absorption test is a prompt and economical means to rule out true malabsorption, decrease unwarranted subspecialty referrals and validate the weight-adjusted LT4 dose reduction.

Small animal models play an important role in investigating and revealing the molecular determinants and mechanisms underlying neuro-virulence of enterovirus A71 (EV-A71). In our previous study, we successfully developed two mouse cell-line replication competent EV-A71 strains (EV71:TLLm and EV71:TLLmv) which were capable of inducing neuro-invasion in BALB/c mice. The more virulent EV71:TLLmv exhibited ability to induce acute encephalomyelitis accompanied by neurogenic pulmonary oedema. EV71:TLLcho virus strain was generated from EV71:TLLm by a series of passages in CHO-K1 cells. EV71:TLLcho demonstrated a broader range of infectivity across various mammalian cell lines and exhibited complete cytopathic effects (CPE) within 48 hours post-inoculation in comparison to EV71:TLLm or EV71:TLLmv. EV71:TLLcho consistently yielded higher levels of viral replication at all time points examined. In comparison to EV71:TLLm, EV71:TLLcho consistently induced more severe disease and increased mortality in one-week old BALB/c mice. However, unlike mice challenged with EV71:TLLmv, none of the mice challenged with EV71:TLLcho progressed to severe acute encephalomyelitis and developed neurogenic pulmonary oedema.

Introduction: Sex estimation is crucial in forensic anthropology. In situations such as mass disasters, and forensic anthropology cases, sex estimation is a very important initial step in the disaster victim identification process. Literature has acknowledged that sex estimation is population-specific. However, sex estimation standards in South-East Asian populations are limited, leading to the usage of most Thais discriminant function equations on sex estimation by other South-East Asian countries including Malaysia. This systematic review was conducted to summarise the findings of sex estimation studies in South-East Asian countries.

Materials and methods: A systematic literature search was performed through the SCOPUS database and Web of Science (WOS) database for relevant studies between 2014 and 2022. All published articles that are related to sex estimation from different types of bone, methods, landmarks, and sample sources (i.e., photographs, dry bones, and CT images) were included in this review. The main inclusion criteria were studies on (i) sex estimation; (ii) in South-East Asian populations; (iii) between the years 2014 and 2022; and (iv) in English.

Results: The literature search identified 30 potentially relevant studies, of which 15 publications met all the inclusion criteria. From those research, 13 studies were related to the Thai population and two to the Malaysian population. Only one study was based on morphological traits, while the rest were based on a morphometric approach.

Conclusion: All studies found that sex estimation is populationspecific. Therefore, further research is recommended to explore more on population-specific sex estimation using different parts of bone.

Introduction: Beta-lactamase producing bacterial infection has been on surge due to selection pressure and injudicious antibiotics usage. Organisms that co-produced more than one beta lactamase enzyme posed diagnostic challenges which may result in inadequate treatment. To date, there is no standardised guideline offering phenotypic detection of AmpC β-lactamase. The purpose of this study was to determine the prevalence of ESBLs, AmpC β-lactamase and co-producer organisms in a teaching hospital.

Materials and methods: Three hundred and four isolates of E. coli and Klebsiella sp. had been selected via convenient sampling. These isolates were identified using conventional laboratory methods and their antimicrobial susceptibilities were determined using disc diffusion method. Those isolates were then proceeded with ESBL confirmatory test, cloxacillin-containing Muller Hinton confirmatory test, modified double disk synergy test and AmpC disk test.

Results: Out of 304 isolates, 159 isolates were E. coli and 145 were Klebsiella sp. The prevalence of organisms which co-produced AmpC β-lactamase and ESBL enzymes were 3.0%. Besides that, 39 cefoxitin resistant and three cefoxitin susceptible isolates (13.8%) were proven to produce AmpC β-lactamase through AmpC disk test. Through the CLSI confirmatory test, 252 (82.9%) isolates were identified as ESBLs producers and the prevalence increased slightly when cloxacillin-containing Muller Hinton were used. Only three ESBLs positive organisms were positive for modified double disk synergy test.

Conclusion: Distinguishing between AmpC β-lactamase and ESBL-producing organisms has epidemiological significance as well as therapeutic importance. Moreover, AmpC β-lactamase and ESBLs co-producing organisms can lead to false negative ESBL confirmatory test. Therefore, knowing the local prevalence can guide the clinician in navigating the treatment.

This work highlights the role of the clinical laboratory, in the early detection of the use of substances prohibited for doping. This is because most people who practice sports today are non-professional athletes and amateurs, in particular young kids. These persons are not subjected to anti-doping controls but are at risk for their health. Endocrinologists and laboratory tests, by detecting evidence of such usage can help protect their health. Anti-doping testing require specific instruments for qualitative and quantitative chemistry, to meet regulations of official competitions but are impossible to be used in every person because of high cost. A particular role the clinical laboratory can acquire in the future is through its molecular biology sections, when genetic doping will probably be a reality and quantitative chemistry will be unable to detect it. A brief history of doping is provided to understand the reasons of its spread. Although doping has great resonance nowadays, it is not a recent problem. It was common among ancient Greek wrestlers and Romans, who used mixtures of herbs and stimulants. Ancient Greece started the Olympic Games and winners assumed great esteem, akin to demi-god status. Therefore, any attempt to improve athletic performance was a norm, also because the damage caused by the substances used was not known at that time. The use became so widespread that soldiers also used drugs to better combat during recent wars, and doping was practiced by athletes, actors and musicians in attempts to obtain better performance results. Today, doping has been refined so as not to be discovered and there is a continuous race between those who promote new substances and those who, like the World Anti-Doping Agency (WADA), were created to defend the health of athletes and comply with regulations of competitions. The clinical laboratory plays a fundamental role in identifying the use of prohibited substances, especially in competitions not classified as official, which are the majority and involve thousands of amateurs. In this paper a series of laboratory tests are proposed in this perspective, at low cost without the need of qualitative/quantitative chemical analyses required by the sport jurisdictions. Finally, a glance into genetic doping illustrates a likely future and imminent practice.