University of Peradeniya

About: University of Peradeniya is a education organization based out in Kandy, Sri Lanka. It is known for research contribution in the topics: Population & Poison control. The organization has 5970 authors who have published 7388 publications receiving 197002 citations.

Prevalence of oral cancer and pre-cancer and associated risk factors among tea estate workers in the central Sri Lanka.

Abstract: Background: To screen for oral cancer or not is being debated, but for high-risk populations with minimal access to regular dental care systematic oral examinations could provide some benefit. Methods: We undertook oral mucosal examinations of labourers employed in tea estate plantations in Sri Lanka. In a two-stage screening procedure, first by estate medical officers and then by visiting specialists, we examined 12 716 persons at their workplaces achieving a coverage of one-sixth of the total workforce. Results: Fourteen oral cancers and 848 subjects with oral pre-cancer (6.7%) were detected giving population prevalences of 46.1 per 1000 for leukoplakia and 16.4 per 1000 for oral submucous fibrosis. Among subjects with any oral mucosal disorder (n = 1159) proportions of current users of betel quid, smokers and alcohol use was recorded at 92%, 31% and 61% respectively. The synergistic effect of these three risk habits on the development of oral leukoplakia was evident in mixed habit groups. Conclusions: The prevalence of oral pre-cancer in tea estate labourers was higher than estimates reported in previous studies. In the absence of state-sponsored preventive activities, it is necessary to improve the capacity of individual health practitioners and small medical centres to participate in oral health promotion and oral cancer/pre-cancer screening.

Review of metastasizing (malignant) ameloblastoma (METAM): pattern of metastasis and treatment.

Abstract: Objectives The rare malignant odontogenic tumor, metastasizing (malignant) ameloblastoma (METAM) is reviewed with the aim of analyzing the pattern of disease and treatment of cervical metastasis based, on 2005 World Health Organization classification. Study design A total of 65 cases, including reported cases from 1923 to 2009 compatible with the current classification and a new case are reviewed. Results METAM occurred mostly in lungs (71%), followed by cervical lymph nodes (28%). Female-to-male ratio was 1:1.1. Primary tumor was diagnosed in 28% of cases at ages ≤20 years, and maxilla-to-mandible ratio was 1:5.2. The mean disease-free interval and survival for pulmonary metastasis were 14.37 years and 3 years, respectively, and 12.96 years and 6 years for cervical METAM. Five-year survival rate for cervical metastasis treated purely surgically was 71.43%. Conclusions According to the available literature, neck dissection is the treatment of choice for cervical METAM. Evidence for the role of chemotherapy and radiotherapy is not conclusive.

Performance Analysis of FDD Massive MIMO Systems Under Channel Aging

Abstract: In this paper, we study the effect of channel aging on the uplink and downlink performance of an FDD massive MIMO system, as the system dimension increases. Since the training duration scales linearly with the number of transmit dimensions, channel estimates become increasingly outdated in the communication phase, leading to performance degradation. To quantify this degradation, we first derive bounds on the mean squared channel estimation error. We use the bounds to derive deterministic equivalents of the receive SINRs, which yields a lower bound on the achievable uplink and downlink spectral efficiencies. For the uplink, we consider maximal ratio combining and MMSE detectors, while for the downlink, we consider matched filter and regularized zero forcing precoders. We show that the effect of channel aging can be mitigated by optimally choosing the frame duration. It is found that using all the base station antennas can lead to negligibly small achievable rates in high user mobility scenarios. Finally, numerical results are presented to validate the accuracy of our expressions and illustrate the dependence of the performance on the system dimension and channel aging parameters.

The prevalence of Early Childhood Caries in 1-2 yrs olds in a semi-urban area of Sri Lanka

Abstract: Background: ECC remains a problem in both developed and developing countries and ECC has been considered to be present in epidemic proportions in the developing countries. The aetiology and associated factors of ECC should be studied adequately to overcome this health hazard. The objective of this study is to determine the prevalence of ECC in 1 to 2 years old children in some selected MOH areas (semi-urban) in the district of Colombo, Sri Lanka. Methods: This study was conducted as a cross sectional study. A total of 422 children aged 1-2 years were selected using systematic sampling technique in Maharagama, Piliyandala, Nugegoda and Boralesgamuwa MOH areas in Colombo district, Western province, Sri Lanka. The pre-test was done initially with 10 children aged 1 1/2 year olds. Prior to the clinical examination of each child, a questionnaire consisting questions regarding tooth brushing, dietary habits, breast and bottle feeding, long term medications(Sweetened medications taken more than 3 months), attending a dental clinic during pregnancy of mother and socio-economical status of the family was administered to mothers of those children. Sterile dental mouth mirrors were used to detect ECC in children. Results: The prevalence of ECC of the whole sample of 410 children aged 1-2 years was 32.19% and the mean dmft was 2.01 and the mean dmfs was 3.83. From the children who had ECC 95% were untreated. There were significant relationships between dmft and long term use of medications (p < 0.000), intake of sugar with milk (p = 0.013), sweet consumption (p = 0.013), employment of mothers (p < 0.000) and visiting a dental clinic during pregnancy (p < 0.000). Conclusions: This study documents high prevalence and severity of ECC among 1-2 years old children in four selected MOH areas of Colombo district and caries in most of the children with ECC (95%) were untreated. Results reveal an urgent need to increase awareness among the public about ECC and institute preventive strategies.

Antifungal activity of black tea polyphenols (catechins and theaflavins) against Candida species.

Abstract: Background/Aims: The polyphenols catechins and theaflavins in black tea have been shown to possess many medicinal properties, including anticancer activity and some antifungal chara