Rahmi Amtha

Prof. Dr. Rahmi Amtha


Research Focus & Metrics

Academic Career Length

13Years (2014-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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20 July 2020 in IEEE Access
Verified
Journal Article
Open access
RWRoshan Alex Welikala
Roshan Alex Welikala
Paolo RemagninoPaolo Remagnino
Paolo Remagnino
JLJian Han Lim
Jian Han Lim
CCChee Seng Chan
Chee Seng Chan
SRSenthilmani Rajendran
Senthilmani Rajendran
SBSarah Ann Barman
Sarah Ann Barman
Oral cancer is a major global health issue accounting for 177,384 deaths in 2018 and it is most prevalent in low- and middle-income countries. Enabling automation in the identification of potentially malignant and malignant lesions in the oral cavity would potentially lead to low-cost and early diagnosis of the disease. Building a large library of well-annotated oral lesions is key. As part of the MeMoSA ® (Mobile Mouth Screening Anywhere) project, images are currently in the process of being gathered from clinical experts from across the world, who have been provided with an annotation tool to produce rich labels. A novel strategy to combine bounding box annotations from multiple clinicians is provided in this paper. Further to this, deep neural networks were used to build automated systems, in which complex patterns were derived for tackling this difficult task. Using the initial data gathered in this study, two deep learning based computer vision approaches were assessed for the automated detection and classification of oral lesions for the early detection of oral cancer, these were image classification with ResNet-101 and object detection with the Faster R-CNN. Image classification achieved an F1 score of 87.07% for identification of images that contained lesions and 78.30% for the identification of images that required referral. Object detection achieved an F1 score of 41.18% for the detection of lesions that required referral. Further performances are reported with respect to classifying according to the type of referral decision. Our initial results demonstrate deep learning has the potential to tackle this challenging task.

6 November 2014 in Asian Pacific Journal of Cancer Prevention
Verified
Journal Article
Open access
PDF file
RARahmi Amtha
Rahmi Amtha
IRIshak Abduk Razak
Ishak Abduk Razak
BBBastaman Basuki
Bastaman Basuki
BRBoedi Oetomo Roeslan
Boedi Oetomo Roeslan
WGWalta Gautama
Walta Gautama
RZRosnah Binti Zain
Rosnah Binti Zain
Tobacco (Kretek) Smoking, Betel Quid Chewing and Risk of Oral Cancer in a Selected Jakarta Population Mouth neoplasms;oral cancer;Indonesia;tobacco;Kretek;betel quid; Purpose: This study aimed to determine the association between tobacco consumption (kretek) and betel quid chewing with oral cancer risk. Materials and Methods: A total of 81 cases of oral cancers were matched with 162 controls in this hospital-based study. Information on sociodemographic characteristics and details of risk habits (duration, frequency and type of tobacco consumption and betel quid chewing) were collected. Association between smoking and betel quid chewing with oral cancer were analysed using conditional logistic regression. Results: Slightly more than half of the cases (55.6%) were smokers where 88.9% of them smoked kretek. After adjusting for confounders, smokers have two fold increased risk, while the risk for kretek consumers and those smoking for more than 10 years was increased to almost three-fold. Prevalence of betel quid chewing among cases and controls was low (7.4% and 1.9% respectively). Chewing of at least one quid per day, and quid combination of betel leaf, areca nut, lime and tobacco conferred a 5-6 fold increased risk. Conclusions: Smoking is positively associated with oral cancer risk. A similar direct association was also seen among betel quid chewers.

16 September 2024 in Biomedicines
Verified
Journal Article
Open access
PDF file
SASurendra Kumar Acharya
Surendra Kumar Acharya
SSSaptarsi Shai
Saptarsi Shai
YCYee Fan Choon
Yee Fan Choon
IGIndrayadi Gunardi
Indrayadi Gunardi
FHFirstine Kelsi Hartanto
Firstine Kelsi Hartanto
VVVui King Vincent-Chong
Vui King Vincent-Chong
Cancer stem cells (CSCs) represent a subpopulation of cancer cells that are believed to initiate and drive cancer progression. In animal models, xenotransplanted CSCs have demonstrated the ability to produce tumors. Since their initial isolation in blood cancers, CSCs have been identified in various solid human cancers, including oral squamous cell carcinoma (OSCC). In addition to their tumorigenic properties, dysregulated stem-cell-related signaling pathways—Wnt family member (Wnt), neurogenic locus notch homolog protein (Notch), and hedgehog—have been shown to endow CSCs with characteristics like self-renewal, phenotypic plasticity, and chemoresistance, contributing to recurrence and treatment failure. Consequently, CSCs have become targets for new therapeutic agents, with some currently in different phases of clinical trials. Notably, small molecule inhibitors of the hedgehog signaling pathway, such as vismodegib and glasdegib, have been approved for the treatment of basal cell carcinoma and acute myeloid leukemia, respectively. Other strategies for eradicating CSCs include natural compounds, nano-drug delivery systems, targeting mitochondria and the CSC microenvironment, autophagy, hyperthermia, and immunotherapy. Despite the extensive documentation of CSCs in OSCC since its first demonstration in head and neck (HN) SCC in 2007, none of these novel pharmacological approaches have yet entered clinical trials for OSCC patients. This narrative review summarizes the in vivo and in vitro evidence of CSCs and CSC-related signaling pathways in OSCC, highlighting their role in promoting chemoresistance and immunotherapy resistance. Additionally, it addresses methodological challenges and discusses future research directions to improve experimental systems and advance CSC studies.

18 April 2022 in European Journal of Dentistry
Verified
Journal Article
Open access
PDF file
CPCaesary Cloudya Panjaitan
Caesary Cloudya Panjaitan
AWArmelia Sari Widyarman
Armelia Sari Widyarman
RARahmi Amtha
Rahmi Amtha
TATri Erri Astoeti
Tri Erri Astoeti
Objective The aim of this study was to analyze the antibiofilm effectiveness of cinnamon (Cinnamomum burmanii) ethanol extract against Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans in vitro. Material and Methods Phytochemical tests were done to identify the cinnamon extract active substances. Furthermore, a crystal violet biofilm assay was used to analyze biofilm detachment after treatment with different concentrations (15, 10, 7.5, 5, and 2.5%) of cinnamon. Biofilm turbidity was measured at 595-nm wavelength using a microplate reader. Additionally, MTT assay was done to analyze the toxicity level of cinnamon extract on fibroblast cells. Statistical Analysis The obtained data were analyzed for normality using the Kolmogorov–Smirnov test. The differences between each group were analyzed using a one-way analysis of variance statistical test, with a significance level of p <0.05. Results The results showed that the ethanol extract of cinnamon contains active compounds of flavonoids, alkaloids, saponins, tannins, quinones, and terpenoids. MTT result showed the cinnamon extract to be nontoxic. The biofilm assay results showed that all cinnamon concentrations exhibited an antibiofilm effect against P. gingivalis and A. actinomycetemcomitans in all incubation time compared with a negative control (p <0.05). Conclusions Cinnamon extracts were effective in inhibiting biofilm of periodontal pathogens. Cinnamon extract might be useful as an alternative therapy for periodontal diseases. Future studies are still needed to confirm this result in vivo to analyze the efficacy of this extract as mouthwash.

25 April 2022 in Oral Diseases
Verified
Journal Article
Closed access
SRSenthilmani Rajendran
Senthilmani Rajendran
JLJian Han Lim
Jian Han Lim
KYKohgulakuhan Yogalingam
Kohgulakuhan Yogalingam
TKThomas George Kallarakkal
Thomas George Kallarakkal
RZRosnah Binti Zain
Rosnah Binti Zain
SCSok Ching Cheong
Sok Ching Cheong

1 January 2025 in Asian Pacific Journal of Cancer Prevention
Verified
Journal Article
Open access
PDF file
AKAngelita Victoria Kurniawan
Angelita Victoria Kurniawan
RARahmi Amtha
Rahmi Amtha
IGIndrayadi Gunardi
Indrayadi Gunardi
AHAlyah Heriandi
Alyah Heriandi
ESElizabeth Fitriana Sari
Elizabeth Fitriana Sari
Objective: To compare the salivary profiles of smokers (e-cigarette smokers, e-cigarette and former conventional cigarette smokers, dual users, and conventional cigarette smokers) and non-smokers in adolescents, focusing on acidity level, flow rate, viscosity, as well as the quantity of Streptococcus mutans, Porphyromonas gingivalis, and Candida albicans. Methods: This analytical observational study, with a cross-sectional design, involves collecting saliva samples from five groups through the draining method. Saliva viscosity was assessed visually, while saliva flow rate was monitored over a ten-minute period. Quantification of bacterial presence was performed using qPCR, and salivary acidity was determined using a digital pH meter. Chi square and t-test were used to analyze the data. Result: The total of 390 subjects (smokers n=195; non-smokers n=195), aged 17-25 years, participated in the study. Dual smokers exhibited a notable decrease in salivary pH (p=0.039) compared to non-smokers. Furthermore, significant reductions in flow rate (p<0.001) were observed across the five groups, however, no significant differences were found in saliva viscosity (p=0.070). When considering the four groups excluding conventional cigarette smokers, significant differences were observed in the quantity of Porphyromonas gingivalis (p=0.010) and Candida albicans (p=0.005). Conversely, the prevalence of Streptococcus mutans did not exhibit a significant difference (p=0.635). Conclusion: The study demonstrates that salivary pH, flow rate, and quantity of P. gingivalis as well as C. albicans are significantly different among the five groups.