Displaying publications 461 - 480 of 660 in total

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  1. Lim KP, Hamid S, Lau SH, Teo SH, Cheong SC
    Oncol Rep, 2007 Jun;17(6):1321-6.
    PMID: 17487385 DOI: 10.3892/or.17.6.1321
    Inactivation of the retinoblastoma (pRB) pathway is a common event in oral squamous cell carcinoma particularly through the aberrant expression of the components within this pathway. This study examines the alterations of molecules within the pRB pathway by looking at the presence of homozygous deletions in p16(INK4A) and the expression patterns of pRB, cyclin D1 and CDK4, as well as the presence of human papillomavirus (HPV) in our samples. In our study, 5/20 samples demonstrated deletions of p16(INK4A) exon 1alpha. pRB overexpression was found in 20/20 samples, the expression was mainly observed in all layers of the epithelia, particularly in the basal layer where cells are actively dividing and aberrant pRB expression was found in 12/20 samples. Cyclin D1 and CDK4 overexpression was detected in 6/20 and 2/20 samples respectively in comparison to hyperplasias where both proteins were either not expressed or expressed at minimal levels (<10%). Strikingly, HPV was found to be present in all of our samples, suggesting that HPV plays a significant role in driving oral carcinogenesis. Notably, 17/20 of our samples showed more than one alteration in the pRB pathway, however, we did not find any significant relationship between the presence of HPV, homozygous deletion of p16(INK4A) and overexpression of pRB, cyclin D1 and CDK4. Collectively, this data demonstrates that alterations in the pRB pathway are a common event and involve the aberration of more than one molecule within the pathway. Furthermore, the involvement of HPV in all our samples suggests that HPV infection may play an important role in oral carcinogenesis.
    Matched MeSH terms: Mouth Neoplasms/etiology*; Mouth Neoplasms/metabolism; Mouth Neoplasms/virology
  2. Lim KP, Sharifah H, Lau SH, Teo SH, Cheong SC
    Oncol Rep, 2005 Oct;14(4):963-8.
    PMID: 16142358 DOI: 10.3892/or.14.4.963
    The majority of global incidences of oral cancer occur in Asia, and the aetiology of oral cancer is different in Asia as it is in the West. However, whereas there is a growing understanding of the molecular mechanisms of oral cancer progression in the West, there is little progress in this understanding in Asia. In particular, the role of the p53 pathway in modulating cancer progression in Asian oral cancer remains unclear. In this study, we micro-dissected and analysed 20 well-differentiated oral squamous cell carcinoma specimens for alterations in the p53 pathway. We found that 6/20 samples contained mutations in the p53 gene which occurred in three hotspots, at codon 203, 218 and 296. Furthermore, 6/20 samples had a homozygous deletion of p14ARF, but notably p14ARF deletion and p53 mutation events were often independent and mutually exclusive. Strikingly, MDM2 was upregulated in 20/20 samples, but not in 3/3 normal tissue specimens. Taken together, these data suggest that inactivation of the p53 pathway is a frequent event in oral squamous cell carcinoma, which occurs by an aberration in one of a number of players in the p53 pathway.
    Matched MeSH terms: Mouth Mucosa/pathology; Mouth Neoplasms/metabolism*
  3. Hamid S, Lim KP, Zain RB, Ismail SM, Lau SH, Mustafa WM, et al.
    Int J Mol Med, 2007 Mar;19(3):453-60.
    PMID: 17273794
    We have established 3 cell lines ORL-48, -115 and -136 from surgically resected specimens obtained from untreated primary human oral squamous cell carcinomas of the oral cavity. The in vitro growth characteristics, epithelial origin, in vitro anchorage independency, human papilloma-virus (HPV) infection, microsatellite instability status, karyotype and the status of various cell cycle regulators and gatekeepers of these cell lines were investigated. All 3 cell lines grew as monolayers with doubling times ranging between 26.4 and 40.8 h and were immortal. Karyotyping confirmed that these cell lines were of human origin with multiple random losses and gains of entire chromosomes and regions of chromosomes. Immunohistochemistry staining of cytokeratins confirmed the epithelial origin of these cell lines, and the low degree of anchorage independency expressed by these cell lines suggests non-transformed phenotypes. Genetic analysis identified mutations in the p53 gene in all cell lines and hypermethylation of p16INK4a in ORL-48 and -136. Analysis of MDM2 and EGFR expression indicated MDM2 overexpression in ORL-48 and EGFR overexpression in ORL-136 in comparison to the protein levels in normal oral keratinocytes. Analysis of the BAT-26 polyadenine repeat sequence and MLH-1 and MSH-2 repair enzymes demonstrated that all 3 cell lines were microsatellite stable. The role of HPV in driving carcinogenesis in these tumours was negated by the absence of HPV. Finally, analysis of the tissues from which these cell lines were derived indicated that the cell lines were genetically representative of the tumours, and, therefore, are useful tools in the understanding of the molecular changes associated with oral cancers.
    Matched MeSH terms: Mouth Neoplasms/epidemiology*; Mouth Neoplasms/pathology*; Mouth Neoplasms/virology
  4. Siti Aisyah Abd Ghafar, Muhammad Fikhry Mohd Salehuddin,, Nur Syamimi Syuhada Che Awang, Rohazila Mohamad Hanafiah
    MyJurnal
    Introduction:Spilanthes acmella, also known as “subang nenek’, has been used traditionally in Malaysia to treat toothache. A previous study has shown Spilanthes acmella leaves extracts (SALE) inhibit Streptococcus mutans growth. Streptococcus mutans is commonly found in the human oral cavity and is the main contributor to tooth de-cay. There is no study on the antibacterial effects of Spilanthes acmella flower extracts (SAFE) against Streptococcus mutans reported to date. Therefore, the objective of this study is to investigate antibacterial properties of SAFE against S. mutans. Methods:S. mutans was subcultured in Muller Hinton (MH) broth and agar. Sequential extractions of S. acmella flowers were conducted using four different solvents with increasing polarity, [n- hexane, dichloromethane (DCM), acetone, methanol (MeoH)] and tested with different concentrations against S. mutans via the disc diffusion assay, minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC). Sodium fluoride (NaF) was used as a positive control while DMSO was used as a negative control. Results: The disc diffusion assay shows SAFE inhibited Streptococcus mutans growth. SAFE-DCM shows the greatest inhibition properties (12.33±2.30 mm) followed by SAFE-n-hexane (11.33±0.57 mm). Meanwhile, SAFE-Meoh and SAFE-acetone show no inhibition zone (6.00±0.001 mm). MIC value for SAFE-DCM and SAFE-n-hexane is 12.5 mg/mL respectively. Whereas, MBC value SAFE-DCM and SAFE-n-hexane is 50.0 mg/mL respectively. Conclusion: It can be concluded SAFE-DCM and SAFE-n-hexane possesses bactericidal properties against Streptococcus mutans.
    Matched MeSH terms: Mouth
  5. Abdul Rahman M, Tan ML, Johnson SP, Hollows RJ, Chai WL, Mansell JP, et al.
    PeerJ, 2020;8:e10328.
    PMID: 33240646 DOI: 10.7717/peerj.10328
    Oral squamous cell carcinoma (OSCC) is the sixth most common cancer worldwide and accounts for 300,000 new cases yearly. The five-year survival rate is approximately 50% and the major challenges to improving patient prognosis include late presentation, treatment resistance, second primary tumours and the lack of targeted therapies. Therefore, there is a compelling need to develop novel therapeutic strategies. In this study, we have examined the effect of lysophosphatidic acid (LPA) on OSCC cell migration, invasion and response to radiation, and investigated the contribution of cyclooxygenase-2 (COX-2) in mediating the tumour promoting effects of LPA. Using the TCGA data set, we show that the expression of the lipid phosphate phosphatases (LPP), LPP1 and LPP3, was significantly down-regulated in OSCC tissues. There was no significant difference in the expression of the ENPP2 gene, which encodes for the enzyme autotaxin (ATX) that produces LPA, between OSCCs and control tissues but ENPP2 levels were elevated in a subgroup of OSCCs. To explore the phenotypic effects of LPA, we treated OSCC cell lines with LPA and showed that the lipid enhanced migration and invasion as well as suppressed the response of the cells to irradiation. We also show that LPA increased COX-2 mRNA and protein levels in OSCC cell lines and inhibition of COX-2 activity with the COX-2 inhibitor, NS398, attenuated LPA-induced OSCC cell migration. Collectively, our data show for the first time that COX-2 mediates some of the pro-tumorigenic effects of LPA in OSCC and identifies the ATX-LPP-LPA-COX-2 pathway as a potential therapeutic target for this disease.
    Matched MeSH terms: Mouth Neoplasms
  6. Procházková M, Füzik T, Grybchuk D, Falginella F, Podešvová L, Yurchenko V, et al.
    J Virol, 2020 Nov 18.
    PMID: 33208443 DOI: 10.1128/JVI.01957-20
    Leishmania parasites cause a variety of symptoms, including mucocutaneous leishmaniasis, which results in the destruction of the mucous membranes of the nose, mouth, and throat. The species of Leishmania carrying Leishmania RNA virus 1 (LRV1), from the family Totiviridae, are more likely to cause severe disease and are less sensitive to treatment than those that do not contain the virus. Although the importance of LRV1 for the severity of leishmaniasis was discovered a long time ago, the structure of the virus remained unknown. Here, we present a cryo-electron microscopy reconstruction of the virus-like particle of LRV1 determined to a resolution of 3.65 Å. The capsid has icosahedral symmetry and is formed by 120 copies of a capsid protein assembled in asymmetric dimers. RNA genomes of viruses from the family Totiviridae are synthetized, but not capped at the 5' end, by virus RNA-polymerases. To protect viral RNAs from degradation, capsid proteins of totivirus L-A cleave the 5' caps of host mRNAs, creating decoys to overload the cellular RNA quality control system. Capsid proteins of LRV1 form positively charged clefts, which may be the cleavage sites for the 5' cap of Leishmania mRNAs. Capsid proteins of LRV1 contain a putative RNA binding site distinct from that of the related L-A virus. The structure of the LRV1 capsid enables the rational design of compounds targeting the putative de-capping site. Such inhibitors may be developed into a treatment for mucocutaneous leishmaniasis caused by LRV1-positive species of LeishmaniaIMPORTANCE Twelve million people worldwide suffer from leishmaniasis, resulting in more than thirty thousand deaths annually. The disease has several variants that differ in their symptoms. The mucocutaneous form, which leads to disintegration of the nasal septum, lips, and palate, is predominantly caused by Leishmania parasites carrying Leishmania RNA virus 1 (LRV1). Here, we present the structure of the LRV1 capsid determined using cryo-electron microscopy. Capsid proteins of a related totivirus L-A protect viral RNAs from degradation by cleaving the 5' caps of host mRNAs. Capsid proteins of LRV1 may have the same function. We show that the LRV1 capsid contains positively charged clefts that may be sites for the cleavage of mRNAs of Leishmania cells. The structure of the LRV1 capsid enables the rational design of compounds targeting the putative mRNA cleavage site. Such inhibitors may be used as treatments for muco-cutaneous leishmaniasis.
    Matched MeSH terms: Mouth
  7. Hakim I, Yunus MRM
    Medeni Med J, 2020;35(3):271-275.
    PMID: 33110681 DOI: 10.5222/MMJ.2020.88120
    Histopathologically adult extracardiac rhabdomyoma is a benign tumour of mature striated muscle. It is a slow- growing tumour with predilection to occur in head and neck region. They appear mainly as a solitary lesion, and about 15% of them can be multicentric. A 56-year-old man presented to us with the floor of mouth swelling persisted for one year and the right neck swelling for three years mimicking a plunging ranula. Radiological imaging revealed enhancing mass at the floor of mouth and submandibular region. The mass represented a nonvascular benign tumour. Subsequently, the patient underwent excision of the mass via transcervical and transoral method. Histopathological examination revealed adult type of extracardiac rhabdomyoma. Adult type of extracardiac rhabdomyoma should be considered in the differential diagnosis for the head and neck masses. A complete excision will reduce the risk of recurrence.
    Matched MeSH terms: Mouth Floor
  8. Lee, Han Hing, Lee, Chee Yen, Shoji, Yoshinobu, Chin, Hoe Teh
    Compendium of Oral Science, 2015;2(1):40-46.
    MyJurnal
    Background: Saliva is a readily accessible biofluid that is important for the overall quality of life, func-tionally essential in the chewing, swallowing, tasting, regulation mouth flora and prevention of caries. The aim of this study is to assess the global metabolomic profile of saliva in healthy Malaysian adults. Methods: As a first step to determining and understanding the metabolomic profile of saliva in healthy Malaysian adults, we have collected saliva samples of 50 adults and measured the salivary metabolite to establish a profiling metabolite data, Human Metabolome Database (HMDB). Metabolites concentrations of saliva in healthy subjects were measured by using 1H NMR spectroscopy. Results: The results showed there was no significant inter-individual variations of the key metabolites observed among the healthy Malaysian adults and there was no significant variation of the metabolites between female and male subjects. Conclusion: The metabolomic profile of saliva in healthy Malaysian adults could be used to establish the metabolomic database and used as a comparison for future study of the saliva of specific diseases.
    Matched MeSH terms: Mouth
  9. Thomson PJ, Goodson ML, Smith DR
    J Oral Pathol Med, 2018 Jul;47(6):557-565.
    PMID: 29663518 DOI: 10.1111/jop.12716
    BACKGROUND: Clinically identifiable potentially malignant disorders (PMD) precede oral squamous cell carcinoma development. Oral lichenoid lesions (OLL) and proliferative verrucous leukoplakia (PVL) are specific precursor lesions believed to exhibit both treatment resistance and a high risk of malignant transformation (MT).

    METHODS: A retrospective review of 590 PMD patients treated in Northern England by CO2 laser surgery between 1996 and 2014 was carried out. Lesions exhibiting lichenoid or proliferative verrucous features were identified from the patient database and their clinicopathological features and outcome post-treatment determined at the study census date of 31 December 2014.

    RESULTS: One hundred and 98 patients were identified as follows: 118 OLL and 80 PVL, most frequently leukoplakia at ventrolateral tongue and floor of mouth sites, equally distributed between males and females. Most exhibited dysplasia on incision biopsy (72% OLL; 85% PVL) and were treated by laser excision rather than ablation (88.1% OLL; 86.25% PVL). OLL were more common in younger patients (OLL 57.1 year; PVL 62.25 years; P = .008) and more likely than PVL to present as erythroleukoplakia (OLL 15.3%; PVL 2.5%; P = .003). Whilst no significant difference was seen between OLL and PVL achieving disease-free status (69.5% and 65%, respectively; P = .55), this was less than the overall PMD cohort (74.2%). MT was identified in 2 OLL (1.7%) and 2 PVL (2.5%) during follow-up.

    CONCLUSION: One-third of PMD cases showed features of OLL or PVL, probably representing a disease presentation continuum. Post-treatment disease-free status was less common in OLL and PVL, although MT was infrequent.

    Matched MeSH terms: Mouth Floor
  10. Zauki NAM, Satyanarayana B, Fairuz-Fozi N, Nelson BR, Martin MB, Akbar-John B, et al.
    Data Brief, 2019 Feb;22:458-463.
    PMID: 30619923 DOI: 10.1016/j.dib.2018.12.027
    The data available in this repository were gathered from Balok, the only most productive spawning site for horseshoe crabs Tachypleus gigas and Carcinoscorpius rotundicauda in East Coast of Peninsular Malaysia. The mangrove horseshoe crab, C. rotundicauda population and spawning data are available in the first table. The horseshoe crabs were retrieved from Balok River using 11.43 cm mesh size gill nets installed at the river mouth, the confluence and last meander. The arthropods were inspected for damage, abnormality and growth before their release into Balok River, particularly at the site of capture. Sediment samples were retrieved at their spawning grounds to ascertain sediment composition and size classifications which were also processed using Logarithmic Method of Moments. Water parameters like temperature, pH and salinity were also investigated during year 2016. All these information are compiled into the second table and arranged according to the period of data availability. The horseshoe crab catch data of years 2012, 2013, 2014, 2015 and 2016 were made available by artisanal fisher and compiled in the third and fourth table for inter-species comparison.
    Matched MeSH terms: Mouth
  11. Kawamura, Gunzo, Bagarinao, Teodora Uy, Nur Syallinaz Seniman, Yong, Annita Seok-Kian, Lim, Leong-Seng
    MyJurnal
    Combining feeding appendage morphology and behavioural observation of the motion pattern of the feeding appendages clarified many aspects underlying the feeding processes of the giant freshwater prawn (Macrobrachium rosenbergii) and the marine whiteleg shrimp (Litopenaeus vannamei) in aquaria. The food intake behaviour was video recorded during eating pellet food, and pieces of fresh squid and fish. While M. rosenbergiitook pellet one by one, L. vannamei picked up many pellets at one time and held them at the mouth with the 3rd maxilliped endopods and the 1st walking legs. Both species used the right chelate walking legs rather than the left walking legs to pick up the food. The 3rd walking legs of L. vannameiwere longest and heaviest among the chelate walking legs but their major role was not for feeding but for feeding contests often in the form of aggression. While M. rosenbergii easily crunched pellets by the mandibles, L. vannamei did not crunch pellets due to the softer and not so strong mandibles and frequently spat out them, indicating that the present hard pellets are not suitable for L. vannamei. Both the species kept a piece of elastic fresh squid or fish flesh at the mouth and tore the food into small pieces with the help of repeated pulling down motion of the 3rd maxilliped endopods. However, the mandible teeth of the two spices were not sharp enough to gnaw off the fibrous muscle in one bite. The 2nd and 3rd maxilliped endopods were used for holding food at the mouth and did not contribute to mastication of food. The 2nd and 3rd maxilliped exopods exhibited the horizontal fanning motion, which caused a unidirectional water flow moving backwards in the gill chamber (visualized with milk). The maxilliped exopods were found to contribute not to feeding but ventilation. Based on the results obtained, development of softer pellets was recommended for L. vannamei.
    Matched MeSH terms: Mouth
  12. Khoo XH, Paterson IC, Goh BH, Lee WL
    Cancers (Basel), 2019 Aug 14;11(8).
    PMID: 31416147 DOI: 10.3390/cancers11081166
    Drug resistance remains a severe problem in most chemotherapy regimes. Recently, it has been suggested that cancer cell-derived extracellular vesicles (EVs) could mediate drug resistance. In this study, the role of EVs in mediating the response of oral squamous cell carcinoma (OSCC) cells to cisplatin was investigated. We isolated and characterized EVs from OSCC cell lines showing differential sensitivities to cisplatin. Increased EV production was observed in both de novo (H314) and adaptive (H103/cisD2) resistant lines compared to sensitive H103 cells. The protein profiles of these EVs were then analyzed. Differences in the proteome of EVs secreted by H103 and H103/cisD2 indicated that adaptation to cisplatin treatment caused significant changes in the secreted nanovesicles. Intriguingly, both resistant H103/cisD2 and H314 cells shared a highly similar EV protein profile including downregulation of the metal ion transporter, ATP1B3, in the EVs implicating altered drug delivery. ICP-MS analysis revealed that less cisplatin accumulated in the resistant cells, but higher levels were detected in their EVs. Therefore, we inhibited EV secretion from the cells using a proton pump inhibitor and observed an increased drug sensitivity in cisplatin-resistant H314 cells. This finding suggests that control of EV secretion could be a potential strategy to enhance the efficacy of cancer treatment.
    Matched MeSH terms: Mouth Neoplasms
  13. Le MHT, Noor Hayaty AK, Zaini ZM, Dom SM, Ibrahim N, Radzi ZB
    Korean J Orthod, 2019 Jul;49(4):235-245.
    PMID: 31367578 DOI: 10.4041/kjod.2019.49.4.235
    Objective: This study examined bone microstructure restoration after rapid maxillary expansion (RME) with and without corticotomy over multiple retention periods.

    Methods: Eighteen male Dorper sheep were randomly distributed into three groups (n = 6 each group): group 1, RME with corticotomy on the buccal and palatal sides; group 2, conventional RME treatment; and group 3, no treatment. Post-RME, trabecular bone microstructure and new bone formation were evaluated by using microcomputed tomography (microCT) and histomorphometry after a 4- or 12-week retention period. Intergroup differences in bone quality and bone remodeling were analyzed by using two-way analysis of variance with Bonferroni post-hoc test.

    Results: The bone volume fraction (bone volume [BV]/total volume [TV]) values relative to the control in groups 1 and 2 were 54.40% to 69.88% after the 4-week retention period and returned to approximately 80% after the 12-week retention period. The pooled BV/TV values of the banded teeth in groups 1 and 2 were significantly lower than those of the control after the 4-week retention period (p < 0.05). However, after the 12-week retention period, the pooled BV/TV values in group 2 were significantly lower than those in groups 1 and 3 (p < 0.05). Histomorphological analysis showed that the new bone formation area in group 1 was approximately two to three times of those in group 2 and control.

    Conclusions: Corticotomy significantly enhanced the restoration of bone quality after the retention periods for banded teeth. This benefit might result from the increased new bone formation after corticotomy.

    Matched MeSH terms: Mouth
  14. Jadhav KB, Nagraj SK, Arora S
    J Oral Pathol Med, 2020 Nov 21.
    PMID: 33220092 DOI: 10.1111/jop.13134
    BACKGROUND: miRNA is one of the advanced epigenetic molecular markers correlating with lymph node metastasis in patients with Oral squamous cell carcinoma (OSCC). Numerous published papers are showing correlation of miRNA with metastasis. There is a need to analyze and validate such correlation.

    METHOD: English language literature in major databases from the last 20 years was searched using controlled vocabulary and keywords. Strict inclusion and exclusion criteria were followed for selection of studies. The quality assessment was done as per the QUADAS tool 2 by three independent reviewers. The metanalysis was performed by using random effect model. Standardized mean difference (SMD) was considered as the effect measure. Statistical software used was STATA version 13.1.

    RESULTS: With all inclusion and exclusion criteria, eight studies could qualify for metanalysis. The pooled estimate is found to be 0.13 (-0.35, 0.62), P = .585, which is statistically not significant. This indicates that there is a no significant difference in the fold change between metastasis and no metastasis groups. P-value of chi-square statistic for heterogeneity is

    Matched MeSH terms: Mouth Neoplasms
  15. Syhidatul Farhana Othman, Juliana Jalaludin, Nur Hazirah Hisamuddin, Noeroel Widajati
    MyJurnal
    Introduction: Exposure of PM2.5 and PM10 released from combustion of biomass activity caused respiratory health among children. Objective: This study aims to determine the association between exposure of PM2.5 and PM10 with DNA damage in primary school children living nearby palm oil combustion activity at Semenyih. Methods: A cross sectional comparative study were conducted among Malay primary school children in school A located 2.7km from palm oil activity (N=82) and school B located about 40km away from the palm oil area (N=85). A standardized ques- tionnaire were distributed to respondent’s parents. Concentrations of PM2.5 and PM10 were measured by using Dust Trak DRX Aerosol Monitor Model 8534 and Escort LC Personal Sampling Pump. Measurement of indoor and outdoor air pollutants were conducted in schools and home. Buccal cells were collected, which then followed by micronu- cleus assay. Results: Concentration of PM10 and PM2.5 at home of studied group were significantly higher compared to comparative group with p value (p=0.007) and (p=0.018) respectively. PM10 and PM2.5 of studied schools were significantly higher compared to comparative schools with p value (p=0.014) and (p=0.04) respectively. MN fre- quencies of studied group were significantly higher compared to comparative group (p=0.001). Significant difference of respiratory symptoms were found between two groups which are cough, phlegm, wheezing and chest tightness (p=0.001). There were significant correlation between PM10 with MN frequency of studied group and comparative group with r= 0.562; p=0.001. Conclusion: This study indicated that the exposure of PM10 and PM2.5 would increase the risk of having respiratory health symptoms and might induce the micronuclei formation among children who lived near palm oil activity area.
    Matched MeSH terms: Mouth Mucosa
  16. Yusof MYPM, Mah MC, Reduwan NH, Kretapirom K, Affendi NHK
    Saudi Dent J, 2020 Dec;32(8):396-402.
    PMID: 33304083 DOI: 10.1016/j.sdentj.2019.10.010
    Objective: Knowledge and evaluation of the blood supply within the maxillary sinus before sinus augmentation are vital to avoid surgical complications. The lateral maxilla is supplied by branches of the posterior superior alveolar artery and infraorbital artery forming intraosseous anastomoses (IA) within the bony lateral antral wall. This study was undertaken to (i) measure mean diameter of IA and its distance from the alveolar ridge within dentate and posteriorly edentulous subjects and, (ii) qualitatively display the relationship of IA throughout its course within the lateral maxillary sinus in cone beam computed tomography (CBCT).

    Method: Maxillary CBCT images of two-hundred-and-fifty-seven consecutive patients (163 men, 94 women, mean age 42 years) were analyzed. Samples were later divided into dentate (n = 142) and posteriorly edentulous (n = 115) jaws. Using both alveolar ridge and tooth location as reference points, the distance and diameter of IA were assessed.

    Result: The IA was seen in 63.7% of all sinuses with 68.2% in dentate and 62.4% in edentulous. Mean distance and diameter of IA across the posterior tooth locations were 17.9 ± 3.0 mm and 1.4 ± 0.5 mm (dentate) and 15.1 ± 3.0 mm and 1.0 ± 0.5 mm (posteriorly edentulous), respectively. In each sample, there were no significant differences in distance-alveolar ridge and no significant correlations in diameter-tooth location. A statistically significant Pearson coefficient correlation between diameter and distance in dentate state was observed (r = -0.6).

    Conclusion: This study reveals that dentate maxillary jaws present larger diameters as compared to posteriorly edentulous jaws, although the IA course remains the same. As these canal structures contain neurovascular bundles with diameters that may be large enough to cause clinically substantial complications, a thorough pre-surgical planning is therefore highly advisable.

    Matched MeSH terms: Mouth, Edentulous
  17. Zulfahmi Said, Hellen Colley, Craig Murdoch
    MyJurnal
    Introduction: Tissue-engineered oral mucosa (TEOM) is increasingly being used to model oral mucosal diseases and to assess drug toxicity. Current TEOM models are constructed using normal oral fibroblasts (NOF) contained within a hydrogel matrix with normal oral keratinocytes (NOK) cultured on top. NOK are not commercially available and suffer from donor-to-donor variability. Therefore, oral mucosal models based on immortalised keratinocytes may offer advantages over NOK-based models. The objective of this study was to construct and characterise the TEOM developed using TERT2-immortalised oral keratinocyte (FNB6) cells and validate its similarity to normal oral muco-sal tissue. Methods: TEOM were constructed by culturing FNB6 cells on top of a NOF-populated collagen type-1 hydrogel in tissue culture transwell inserts cultured at an air-to-liquid interface and collected at 14 day. TEOM were subjected to morphological (H&E and PAS), ultrastructural (TEM) and immunohistological (Ki-67, cytokeratin 14 and E-cadherin) analysis. Results: Histologically TEOM mimicked native oral mucosa displaying a stratified epithelium, fibroblast-containing connective tissue and basement membrane. Furthermore, TEM confirmed the presence of des-mosomes and hemi-desmosomes in the epithelium. IHC revealed expression of differentiation markers (cytokeratin 14), proliferation (Ki-67), cell adhesion (E-cadherin). Conclusion: FNB6 mucosal models able to mimic native oral mucosa structure. It has potential for drug delivery and toxicity evaluation, and replacing models based on NOK where access to primary cells is limited.
    Matched MeSH terms: Mouth Mucosa
  18. Lee HM, Kelly GM, Zainal NS, Yee PS, Fadlullah MZH, Lee BKB, et al.
    Sci Rep, 2019 02 20;9(1):2357.
    PMID: 30787334 DOI: 10.1038/s41598-019-38742-0
    The use of EGFR inhibitors on oral squamous cell carcinoma (OSCC) as monotherapy yielded modest clinical outcomes and therefore would benefit from biomarkers that could predict which patient subsets are likely to respond. Here, we determined the efficacy of erlotinib in OSCC cell lines, and by comparing sensitive and resistant lines to identify potential biomarkers. We focused on the 4717C > G polymorphism in periplakin (PPL) where the CC genotype was associated with erlotinib resistance. To validate this, erlotinib-resistant cell lines harbouring CC genotype were engineered to overexpress the GG genotype and vice versa. Isogenic cell lines were then studied for their response to erlotinib treatment. We demonstrated that overexpression of the GG genotype in erlotinib-resistant lines sensitized them to erlotinib and inhibition of AKT phosphorylation. Similarly, the expression of the CC genotype conferred resistance to erlotinib with a concomitant increase in AKT phosphorylation. We also demonstrated that cell lines with the CC genotype generally are more resistant to other EGFR inhibitors than those with the GG genotype. Overall, we showed that a specific polymorphism in the PPL gene could confer resistance to erlotinib and other EGFR inhibitors and further work to evaluate these as biomarkers of response is warranted.
    Matched MeSH terms: Mouth Neoplasms
  19. Yee PS, Zainal NS, Gan CP, Lee BKB, Mun KS, Abraham MT, et al.
    Target Oncol, 2019 04;14(2):223-235.
    PMID: 30806895 DOI: 10.1007/s11523-019-00626-8
    BACKGROUND: Given that aberrant activation of epidermal growth factor receptor family receptors (ErbB) is a common event in oral squamous cell carcinoma, and that high expression of these receptor proteins is often associated with poor prognosis, this rationalizes the approach of targeting ErbB signaling pathways to improve the survival of patients with oral squamous cell carcinoma. However, monotherapy with the ErbB blocker afatinib has shown limited survival benefits.

    OBJECTIVES: This study was performed to identify mechanisms of afatinib resistance and to explore potential afatinib-based combination treatments with other targeted inhibitors in oral squamous cell carcinoma.

    METHODS: We determined the anti-proliferative effects of afatinib on a panel of oral squamous cell carcinoma cell lines using a crystal violet-growth inhibition assay, click-iT 5-ethynyl-2'-deoxyuridine staining, and cell-cycle analysis. Biochemical assays were performed to study the underlying mechanism of drug treatment as a single agent or in combination with the MEK inhibitor trametinib. We further evaluated and compared the anti-tumor effects of single agent and combined treatment by using oral squamous cell carcinoma xenograft models.

    RESULTS: In this study, we showed that afatinib inhibited oral squamous cell carcinoma cell proliferation via cell-cycle arrest at the G0/G1 phase, and inhibited tumor growth in xenograft mouse models. Interestingly, we demonstrated reactivation of the mitogen-activated protein kinase (ERK1/2) pathway in vitro, which possibly reduced the effects of ErbB inhibition. Concomitant treatment of oral squamous cell carcinoma cells with afatinib and trametinib synergized the anti-tumor effects in oral squamous cell carcinoma-bearing mouse models.

    CONCLUSIONS: Our findings provide insight into the molecular mechanism of resistance to afatinib and support further clinical evaluation into the combination of afatinib and MEK inhibition in the treatment of oral squamous cell carcinoma.

    Matched MeSH terms: Mouth Neoplasms/drug therapy*; Mouth Neoplasms/metabolism; Mouth Neoplasms/pathology
  20. Sopian NA, Jalaludin J, Abu Bakar S, Hamedon TR, Latif MT
    PMID: 33806616 DOI: 10.3390/ijerph18052575
    This study aimed to assess the association of exposure to particle-bound (PM2.5) polycyclic aromatic hydrocarbons (PAHs) with potential genotoxicity and cancer risk among children living near the petrochemical industry and comparative populations in Malaysia. PM2.5 samples were collected using a low-volume sampler for 24 h at three primary schools located within 5 km of the industrial area and three comparative schools more than 20 km away from any industrial activity. A gas chromatography-mass spectrometer was used to determine the analysis of 16 United States Environmental Protection Agency (USEPA) priority PAHs. A total of 205 children were randomly selected to assess the DNA damage in buccal cells, employing the comet assay. Total PAHs measured in exposed and comparative schools varied, respectively, from 61.60 to 64.64 ng m-3 and from 5.93 to 35.06 ng m-3. The PAH emission in exposed schools was contributed mainly by traffic and industrial emissions, dependent on the source apportionment. The 95th percentiles of the incremental lifetime cancer risk estimated using Monte Carlo simulation revealed that the inhalation risk for the exposed children and comparative populations was 2.22 × 10-6 and 2.95 × 10-7, respectively. The degree of DNA injury was substantially more severe among the exposed children relative to the comparative community. This study reveals that higher exposure to PAHs increases the risk of genotoxic effects and cancer among children.
    Matched MeSH terms: Mouth Mucosa
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