Tau, a family of microtubule-associated proteins, forms abnormal intracellular inclusions, so-called tau pathology, in a range of neurodegenerative diseases collectively known as tauopathies. The rTg4510 mouse model is a well-characterized bitransgenic F1 hybrid mouse model of tauopathy, which was obtained by crossing a Camk2α-tTA mouse line (on a C57BL/6 J background) with a tetO-MAPT*P301L mouse line (on a FVB/NJ background). The aim of this study was to investigate the effects of the genetic background and sex on the accumulation of tau pathology in reciprocal F1 hybrids of rTg4510 mice, i.e., rTg4510 on the (C57BL/6 J × FVB/NJ)F1 background (rTg4510_CxF) and on the (FVB/NJ × C57BL/6 J)F1 background (rTg4510_FxC). As compared with rTg4510_CxF mice, the rTg4510_FxC mice showed marked levels of tau pathology in the forebrain. Biochemical analyses indicated that the accumulation of abnormal tau species was accelerated in rTg4510_FxC mice. There were strong effects of the genetic background on the differential accumulation of tau pathology in rTg4510 mice, while sex had no apparent effect. Interestingly, midline-1 (Mid1) was identified as a candidate gene associated with this difference and exhibited significant up/downregulation according to the genetic background. Mid1 silencing with siRNA induced pathological phosphorylation of tau in HEK293T cells that stably expressed human tau with the P301L mutation, suggesting the role of Mid1 in pathological alterations of tau. Elucidation of the underlying mechanisms will provide novel insights into the accumulation of tau pathology and is expected to be especially informative to researchers for the continued development of therapeutic interventions for tauopathies.
Nevus lipomatosus superficialis is a rare benign skin malformation characterised by ectopic adipocytes in the upper dermis. It is classified into two types: a classical Hoffman-Zurhelle type and the solitary type. A case of the classical type with multiple soft, non-tender, pedunculated, cerebriform, skin-coloured papules and nodules over the right lower back is presented in a 21-year-old Malay woman. She had a rare occurrence of ulceration and necrosis of the lesions.
A case of chondrosarcoma of the nasal septum is presented with the result of treatment. The patient was admitted for a growth in the nose of four years' duration. Fine needle aspiration for cytological examination was suggestive of squamous cell carcinoma. She was treated with lateral rhinotomy and wide excision followed by septorhinoplasty. Histological examination showed that the lesion was chondrosarcoma. The patient remained free of disease 26 months after surgery.
Verrucous carcinoma of the paranasal sinuses is a rare malignant tumour. It occurs most frequently in the oral cavity and larynx. We present a case of extensive verrucous carcinoma of the maxillary sinus. This paper discusses the clinical and histological features and modes of treatment. All previous reports of verrucous carcinoma cases of paranasal sinuses are reviewed.
Malignant osteopetrosis is associated with petrous carotid canal and internal carotid artery stenosis in the skull base. We present a four-year-old boy with malignant osteopetrosis who developed right frontal lobe infarction as a result of bilateral internal carotid artery hypotrophy.
Glomus tumors occurring synchronously in the subungual region and the pulp of a fingertip are extremely uncommon. Awareness of this will lead to early diagnosis and treatment.
Matched MeSH terms: Glomus Tumor/pathology*; Nail Diseases/pathology*; Soft Tissue Neoplasms/pathology*; Neoplasms, Second Primary/pathology*
Molar-Incisor Hypomineralization (MIH) is a condition of hypomineralized enamel of systemic origin affecting first permanent molars and frequently permanent incisors. It is considered a global problem and data from South-East Asian countries, including Malaysia are lacking. Hence the aim of this study were to investigate the distribution and severity of MIH in a group of children aged 7-12 year olds attending pediatric dental clinic at Faculty of Dentistry, Universiti Teknologi MARA (UiTM), Malaysia.
Tumor-associated macrophages play a crucial role in breast cancer progression and tumor angiogenesis. However, evaluation of tumor-associated macrophages incorporating their histological locations is lacking. The aim of this study was to clarify whether macrophages in tumor stroma and macrophages in tumor cell nests have distinctive properties in relation to pertinent breast cancer clinicopathological parameters and tumor angiogenesis. In 94 human invasive breast ductal carcinomas, tumor-associated macrophages were immunostained with anti-CD68 antibody and counted or graded according to these histological locations. Microvessels were immunostained with anti-CD34 antibody and counted for microvessel density. We found that the presence of tumor stromal and tumor nest macrophages was closely correlated (p = 0.001). Both tumor stromal and tumor nest macrophages were associated with mitotic count (p = 0.001 and p = 0.037, respectively). However, only higher tumor stromal macrophage grades were associated with higher tumor grades (p = 0.004) and negative estrogen receptor status (p = 0.007). Multivariate analysis showed that tumors with a high mitotic count score (score 3 vs. scores 1 and 2) had a higher tumor stromal macrophage density (Grades III and IV) when adjusted for tumor size, tubule formation, and estrogen receptor status (odds ratio 3.41, p = 0.010). The tumor nest macrophage count significantly correlated with the microvessel density (p
Alzheimer's Disease (AD) is a progressive neurological disease associated with behavioral abnormalities, memory loss, and cognitive impairment that cause major causes of dementia in the elderly. The pathogenetic processes cause complex effects on brain function and AD progression. The proper protein homeostasis, or proteostasis, is critical for cell health. AD causes the buildup of misfolded proteins, particularly tau and amyloid-beta, to break down proteostasis, such aggregates are toxic to neurons and play a critical role in AD pathogenesis. The rise of cellular senescence is accompanied by aging, marked by irreversible cell cycle arrest and the release of pro-inflammatory proteins. Senescent cell build-up in the brains of AD patients exacerbates neuroinflammation and neuronal degeneration. These cells senescence-associated secretory phenotype (SASP) also disturbs the brain environment. When proteostasis failure and cellular senescence coalesce, a cycle is generated that compounds each other. While senescent cells contribute to proteostasis breakdown through inflammatory and degradative processes, misfolded proteins induce cellular stress and senescence. The principal aspects of the neurodegenerative processes in AD are the interaction of cellular senescence and proteostasis failure. This review explores the interconnected roles of proteostasis disruption and cellular senescence in the pathways leading to neurodegeneration in AD.
We conducted a meta-analysis in order to investigate the relationships between PTEN gene mutations and the prognosis in glioma. The following electronic databases were searched for relevant articles without any language restrictions: Web of Science (1945 ~ 2013), the Cochrane Library Database (Issue 12, 2013), PubMed (1966 ~ 2013), EMBASE (1980 ~ 2013), CINAHL (1982 ~ 2013), and the Chinese Biomedical Database (CBM) (1982 ~ 2013). Meta-analyses were conducted using the STATA software (Version 12.0, Stata Corporation, College Station, Texas USA). Hazard ratio (HR) with its corresponding 95 % confidence interval (95%CI) was calculated. Six independent cohort studies with a total of 357 glioma patients met our inclusion criteria. Our meta-analysis results indicated that glioma patients with PTEN gene mutations exhibited a significantly shorter overall survival (OS) than those without PTEN gene mutations (HR = 3.66, 95%CI = 2.02 ~ 5.30, P < 0.001). Ethnicity-stratified subgroup analysis demonstrated that PTEN gene mutations were closely linked to poor prognosis in glioma among Americans (HR = 3.72, 95%CI = 1.72 ~ 5.73, P < 0.001), while similar correlations were not observed among populations in Sweden, Italy, and Malaysia (all P > 0.05). Our meta-analysis provides direct and strong evidences for the speculation of PTEN gene mutations' correlation with poor prognosis of glioma patients.
BACKGROUND: In Asia, up to 25% of breast cancer patients present with distant metastases at diagnosis. Given the heterogeneous survival probabilities of de novo metastatic breast cancer, individual outcome prediction is challenging. The aim of the study is to identify existing prognostic models for patients with de novo metastatic breast cancer and validate them in Asia.
MATERIALS AND METHODS: We performed a systematic review to identify prediction models for metastatic breast cancer. Models were validated in 642 women with de novo metastatic breast cancer registered between 2000 and 2010 in the Singapore Malaysia Hospital Based Breast Cancer Registry. Survival curves for low, intermediate and high-risk groups according to each prognostic score were compared by log-rank test and discrimination of the models was assessed by concordance statistic (C-statistic).
RESULTS: We identified 16 prediction models, seven of which were for patients with brain metastases only. Performance status, estrogen receptor status, metastatic site(s) and disease-free interval were the most common predictors. We were able to validate nine prediction models. The capacity of the models to discriminate between poor and good survivors varied from poor to fair with C-statistics ranging from 0.50 (95% CI, 0.48-0.53) to 0.63 (95% CI, 0.60-0.66).
CONCLUSION: The discriminatory performance of existing prediction models for de novo metastatic breast cancer in Asia is modest. Development of an Asian-specific prediction model is needed to improve prognostication and guide decision making.
Matched MeSH terms: Breast Neoplasms/pathology; Neoplasm Metastasis/pathology*
Schwannoma (neurilemoma) is a benign, slow-growing tumor of the nerve sheath. These tumors are rarely found in the female genitalia and to date only 1 case of clitoral schwannoma has been reported in a young girl. We report here the second case of schwannoma of the clitoris.
Solid variant of papillary thyroid carcinoma (PTC) is a rare, poorly characterised variant and predominantly reported in children with a history of radiation exposure. This variant has a high propensity for extra-thyroidal extension and cervical lymph node metastases. A 14-year-old Malay girl who had no history of radiation exposure, presented with multiple cervical lymphadenopathy and it was clinically suspicious for tuberculosis or lymphoma. An incisional biopsy revealed a metastatic PTC. The patient underwent total thyroidectomy with bilateral lateral neck dissection and histopathology report was solid variant of PTC. Whole-body I(131) scan was performed which revealed an intense tracer uptake in the neck. She was planned for radioactive iodine ablation and now on regular follow-up for monitoring of possible tumour metastasis.
Synovial sarcoma is a rare soft tissue sarcoma that commonly involves the lower extremities and occurs predominantly in young adults. It very rarely occurs in the head and neck region and carries a poor prognosis. The tumor demonstrates both a loco-regional and a systemic pattern of spread that makes management challenging. Combined modality therapy of this aggressive tumor yields better results. Herein, we described a 58 years old lady presented with left parapharyngeal synovial sarcoma. This is to demonstrate the aggressiveness of the disease despite complete surgical excision followed by post operative radiotherapy. Local regional control was difficult and recurrence of disease was seen in this particular patient.
Acral melanoma involve the non-pigmented palmoplantar and subungual areas and are commonly seen among Asians. Patients commonly display advanced stage of disease at presentation. It may appear unnoticed and mimic benign lesions.
Clear cells can be found in numerous salivary and non-salivary tumors in the head and neck region, including metastatic lesions. They are rare low-grade tumors accounting for less than 1% of all salivary gland tumors and occur almost exclusively in the intra-oral minor salivary glands. Hyalinizing clear cell carcinoma (HCCC) is an extremely rare and recently described neoplasm predominantly affecting the oral cavity. Histologically, it is characterized by nests of glycogen-rich monomorphic clear cells within a hyaline stroma. HCCC often follows an indolent course with a limited metastatic potential. It is therefore important to differentiate this entity from other more aggressive clear cell tumors including metastatic tumors such as renal cell carcinoma. We hereby report a case of HCCC localized in minor salivary glands specifically in soft palate for its rarity, as well as to discuss the role of immunohistochemical stains, essential for its definitive diagnosis.