1.Facial Palsy with Tongue Ulcer: A Rare Initial Presentation of Granulomatosis with Polyangiitis
Ain Nabila Za&rsquo ; im Nur ; Mohd Shawal Firdaus Mohamad ; Noor Afidah Abdullah ; Geok Chin Tan ; Azman Mawaddah
Archives of Orofacial Sciences 2022;17(1):151-156
ABSTRACT
Granulomatosis with polyangiitis (GPA) is a rare multisystem disease. Although GPA is rare, it
commonly presents in a localised stage where its manifestation involves the upper or lower respiratory
tract before progressing to a generalised stage. Therefore, most patients with GPA will visit an oral
surgeon or an otolaryngologist to seek treatment. However, the diagnosis of GPA is often delayed as
GPA is not frequently considered as a differential diagnosis in common oral and facial diseases. The lack
of gold standard investigation for the diagnosis of GPA makes management of this case, a diagnostic
conundrum. We herein report a patient who was diagnosed with bilateral acute otitis media and left
mastoiditis complicated with facial nerve palsy, and later developed tongue ulceration one month after
his initial presentation. The ear, facial and oral symptoms represent a diagnostic red herring to a full-blown generalised stage of GPA.
Facial Paralysis
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Oral Ulcer
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Granulomatosis with Polyangiitis
2.Construction of a doxycycline inducible lentivirus that expresses stem cell-specific miR-302 cluster
The Malaysian Journal of Pathology 2020;42(1):91-97
Introduction: The polycistronic miR-302 cluster encodes five miRNA genes that have an important role in the regulation of embryonic stem cell function. Studies showed that the miR-302 cluster can reprogram both mouse and human fibroblasts to induced pluripotent stem cells (iPSCs) with high efficiency. The aim of this study was to generate an inducible lentivirus that expresses miR-302 cluster in order to further investigate somatic cell reprogramming by these miRNAs. Materials and Methods: The miR-302 cluster was amplified by polymerase chain reaction technique from human genomic DNA and was ligated into pTRIPz, an inducible lentiviral vector. Results: MRC5 fibroblasts and HEK293 (human embryonic kidney) cells were infected with pTRIPz-302 cluster lentivirus and the family of 302 miRNAs were strongly expressed in HEK293 cells but lowly expressed in MRC5 fibroblasts. When cultured in hESC conditions, MRC5 cells expressed only low levels of DNMT3B, Nanog, Oct4 and Lin28 and failed to show stem cell induction. The red fluorescent expression seen in the majority of MRC5 cells, indicated that the rate of infection by lentivirus was efficient. Discussion: The efficiency of reprogramming may be improved perhaps by either using a different cell type or a high expression vector with a different type of promoter.
3.CNS germinoma with extensive calcification: An unusual histologic finding
The Malaysian Journal of Pathology 2019;41(1):71-73
Introduction: Intratumoral calcification is a feature that is more often observed in pineal parenchymal tumour than germinoma. We describe a 13-year-old male with pineal region germinoma demonstrating extensive intratumoral calcification. Case report: He presented with worsening headache that was associated with fatigue, nausea and vomiting. Radiologic examination revealed a multilobular mass in the pineal region with internal calcifications. Biopsy showed a pure germinoma with unusually extensive calcification. Discussion: Although a diagnosis may be suggested with a careful evaluation of imaging, there is no pathognomonic pattern. Thus, histologic verification is necessary for most pineal region masses.
Germinoma
4.The spectrum of pathological findings of tonsils in children: A clinicopathological review
Geok Chin TAN ; Melissa STALLING ; Sura AL-RAWABDEH ; Basil M KAHWASH ; Razan F ALKHOURY ; Samir B KAHWASH
The Malaysian Journal of Pathology 2018;40(1):11-26
Tonsillectomy is among the most commonly performed operations in children. Although follicular lymphoid hyperplasia is usually the main and only pathologic finding at microscopic examination, a variety of other rare but important pathologic changes may be encountered. This review aims to provide an inclusive practical resource and reference for both training and practising pathologists. It discusses the spectrum of pathologic findings, including both neoplastic and non-neoplastic conditions and provides illustrative images.
Tonsil
5.Mesenchymal Stromal Cells from the Maternal Segment of Human Umbilical Cord is Ideal for Bone Regeneration in Allogenic Setting
Jezamine LIM ; Zainul Rashid Mohamad RAZI ; Jia Xian LAW ; Azmawati Mohammed NAWI ; Ruszymah Binti Haji IDRUS ; Tan Geok CHIN ; Muaatamarulain MUSTANGIN ; Min Hwei NG
Tissue Engineering and Regenerative Medicine 2018;15(1):75-87
Umbilical cord (UC) is a discarded product from the operating theatre and a ready source of mesenchymal stromal cells (MSCs). MSCs from UC express both embryonic and adult mesenchymal stem cell markers and are known to be hypoimmunogenic and non-tumorigenic and thus suitable for allogeneic cell transplantation. Our study aimed to determine the degree of immunotolerance and bone-forming capacity of osteodifferentiated human Wharton's jelly-derived mesenchymal stromal cells (hWJ-MSCs) from different segments of UC in an allogenic setting. UCs were obtained from healthy donors delivering a full-term infant by elective Caesarean section. hWJ-MSCs were isolated from 3 cm length segment from the maternal and foetal ends of UCs. Three-dimensional fibrin constructs were formed and implanted intramuscularly into immunocompetent mice. The mice were implanted with 1) fibrin construct with maternal hWJ-MSCs, 2) fibrin construct with foetal hWJ-MSCs, or 3) fibrin without cells; the control group received sham surgery. After 1 month, the lymphoid organs were analysed to determine the degree of immune rejection and bone constructs were analysed to determine the amount of bone formed. A pronounced immune reaction was noted in the fibrin group. The maternal segment constructs demonstrated greater osteogenesis than the foetal segment constructs. Both maternal and foetal segment constructs caused minimal immune reaction and thus appear to be safe for allogeneic bone transplant. The suppression of inflammation may be a result of increased anti-inflammatory cytokine production mediated by the hWJ-MSC. In summary, this study demonstrates the feasibility of using bone constructs derived from hWJ-MSCs in an allogenic setting.
Adult
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Animals
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Bone Regeneration
;
Cell Transplantation
;
Cesarean Section
;
Female
;
Fibrin
;
Humans
;
Infant
;
Inflammation
;
Mesenchymal Stromal Cells
;
Mice
;
Osteogenesis
;
Pregnancy
;
Tissue Donors
;
Tissue Engineering
;
Transplants
;
Umbilical Cord
;
Wharton Jelly
6.Comparative aspects of microRNA expression in canine and human cancers
Kabiru SAHABI ; Gayathri T SELVARAJAH ; Rasedee ABDULLAH ; Yoke Kqueen CHEAH ; Geok Chin TAN
Journal of Veterinary Science 2018;19(2):162-171
MicroRNAs (miRNAs) have important roles in all biological pathways in multicellular organisms. Over 1,400 human miRNAs have been identified, and many are conserved among vertebrates and invertebrates. Regulation of miRNA is the most common mode of post-transcriptional gene regulation. The miRNAs that are involved in the initiation and progression of cancers are termed oncomiRs and several of them have been identified in canine and human cancers. Similarly, several miRNAs have been reported to be down-regulated in cancers of the two species. In this review, current information on the expression and roles of miRNAs in oncogenesis and progression of human and canine cancers, as well the roles miRNAs have in cancer stem cell biology, are highlighted. The potential for the use of miRNAs as therapeutic targets in personalized cancer therapy in domestic dogs and their possible application in human cancer counterparts are also discussed.
Animals
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Biology
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Carcinogenesis
;
Dogs
;
Gene Expression
;
Humans
;
Invertebrates
;
MicroRNAs
;
Neoplastic Stem Cells
;
Stem Cells
;
Vertebrates
7.Beta-human Chorionic Gonadotropin-secreting Lung Adenocarcinoma
Yin Ping Wong ; Geok Chin Tan ; Suraya Aziz ; Sucharit Pongprakyun ; Fuad Ismail
Malaysian Journal of Medical Sciences 2015;22(4):76-80
Overexpression of beta-human chorionic gonadotropin (β-hCG) is frequently associated with germ cell tumours, especially choriocarcinoma. Ectopic secretion of β-hCG by non-small cell lung cancer is exceptional. We present an exceedingly rare case of pulmonary adenocarcinoma that secretes β-hCG. Our patient is a 62-year-old postmenopausal woman, a nonsmoker, who presented with a six-month history of progressive dyspnoea, associated with decreased appetite and significant weight loss. Her serum β-hCG was very high (11211.9 mIU/ml), which prompted investigations to exclude germ cell tumour. Radiological imaging revealed a 10-cm right lung mass with adrenal metastasis. No other focal lesions were detected. Microscopy of the lung biopsy specimen showed replacement of normal lung tissue by sheets of malignant cells, forming vague glands in some areas. Immunohistochemically, the malignant cells showed focal immunopositivity for thyroid transcription factor 1 (TTF-1), napsin A, cytokeratin 7 (CK7) and β-hCG. A diagnosis of β-hCG-secreting pulmonary poorly differentiated adenocarcinoma was rendered. Serum β-hCG level decreased significantly to 168.6 mIU/ml after the first cycle of chemotherapy. In conclusion, β-hCG expression in lung cancer should be recognised to facilitate prompt diagnosis and initiation of appropriate intervention.
8.IsomiRs have functional importance
The Malaysian Journal of Pathology 2015;37(2):73-81
Since the inception of deep sequencing, isomiRs are consistently observed to be produced by most
miRNA genes in a variety of cell types. IsomiRs appear as a variation in length from the canonical
sequence annotated in miRBase, due to an addition or deletion of one or more nucleotides at the
5’ or 3’ ends or both. As the seed sequence is located at the 5’ end of the microRNA, the target
mRNA will be theoretically different. Therefore, 5’isomiRs might potentially target a new set mRNA
compared to their canonical counterpart. This article gives an overview of investigations that explored
the functional potential of isomiRs such as their ability to incorporate into Argonaute protein, the
differential expression of isomiRs in various tissue types and cell lines, and the differences of
mRNA targets between isomiR and its canonical microRNA. In addition, this article provides a
brief introduction of RNA sponges as a potential way to inhibit isomiRs.
9.MicroRNA-induced pluripotent stem cells.
The Malaysian Journal of Pathology 2012;34(2):167-8; author reply 169
10.Myeloid sarcoma of the urinary bladder with cutaneous tumour seeding after percutaneous suprapubic catheterization
Geok Chin TAN ; Masir NORAIDAH ; Noor HAMIDAH Hussin ; Mohd Sidik SHIRAN ; Boon Cheok LEE ; Thean Yean KEW
The Malaysian Journal of Pathology 2011;33(1):47-51
Myeloid sarcoma (MS) is a rare extramedullary myeloid tumour. It has been reported in various
sites, including lymph node, bone, skin, soft tissue, various organs and the CNS. It may precede
or occur concurrently with acute myeloid leukemia. Urinary bladder involvement is extremely
uncommon. We report a 70-year-old female who had MS of the urinary bladder, presented with
frank and persistent hematuria associated with lower abdominal pain. She subsequently had tumour
seeding in the abdominal skin via percutaneous suprapubic catheter. Tumours from both the urinary
bladder and skin showed immature cells that were immunoreactive toward LCA (focal), MPO (strong),
CD99 (weak) and CD117 (weak). Summary of cases in the literature is presented. The potential of
its misdiagnosis and the useful markers for the diagnosis of MS are discussed


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