Research

News & Announcements

Activities for Graduate Students
Thurs 30th Oct 2008: Finding & evaluating information on the internet, 4pm – 7pm, Med Sci Library

Events

Research Seminar Series 2008/2009

We look forward to seeing you in the new academic year.

Calls for Submissions

McLaughlin-Rotman Centre for Global Health (MRC) Call for Proposals

Deadline: January 16, 2009

The McLaughlin-Rotman Centre for Global Health (MRC) and its Ethical, Social and Cultural Program (ESC) for the Grand Challenges in Global Health (GCGH) Initiative are pleased to invite individuals, institutions, organizations and companies from the developing world to submit proposals to carry out projects that will facilitate the implementation and use of technologies in the developing world that arise from the GCGH projects.

The goal of this Request for Proposals (RFP) is to select and commission research on strategies that will facilitate the implementation and appropriate use in the developing world of technologies that arise from the GCGH projects related to diagnostics, modified insect vectors, nutritionally enhanced foods, and vaccine delivery.

Grand Challenges Explorations

Deadline for Application: November 2, 2008

The Bill & Melinda Gates Foundation is now accepting grant proposals for Round 2 of Grand Challenges Explorations, a US$100 million initiative to encourage unconventional global health solutions. Round 2 follows on the heels of the initiative's first funding round, which closed in May of this year, and generated nearly 4,000 applications from scientists in more than 100 countries.

Caribbean Health Research Council 54th Annual Scientific Meeting April 23 - 25, 2009

Deadline for Receipt of Papers: November 1, 2008

The 54th Annual Caribbean Health Research Council Conference will be held in the Turks & Caicos Islands on April 23 – 25, 2009. This is the first time that the CHRC will be hosting its meeting in ‘Beautiful by Nature’ Turks & Caicos Islands, which consists of 40 islands and cays.

Research Areas

Medicinal Natural Products Research

Neuroscience/Neurodegenerative Diseases

Type II Diabetes & Inflammatory Markers

Metabolic Syndrome & COPD Research

This interdisciplinary cluster explores the association of metabolic syndrome with airway disease in a Trinidadian population with type 2 diabetes mellitus. The research will inform on the prevalence of metabolic syndrome and restrictive airway disease (a diagnosis which may be missed), in adult diabetics, utilizing biochemical and clinical markers of inflammation, restrictive airway disease and cardiac disease.

Tropical Medicine Cluster: Infectious Diseases

This group is an interdisciplinary research cluster for the study of infectious diseases in the Neotropics, in order to promote and to improve the health and welfare of humans and animals.

Restorative Dental Sciences

Much of the research interests of the Unit has focused primarily on tooth wear in caribbean populations, dental education and its relation to restorative dentistry and dental materials science.

Child Dental Health/Dental Public Health

Areas of research among members of the unit include: oral health needs in young children, children’s emergency dental care, dental health education, oral health promotion and dental health of people with special needs.

Recent Papers

Anaemia and kidney dysfunction in Caribbean Type 2 diabetic patients. Ezenwaka CE, Jones-LeCointe A, Nwagbara E, Seales D & Okali F. Cardiovascular Diabetology 2008 7:25.

Anaemia has been shown in previous studies to be a risk factor for cardiovascular disease in diabetic patients with chronic kidney disorder. This study was aimed to assess the prevalence of anaemia and kidney dysfunction in Caribbean type 2 diabetic patients that have been previously shown to have a high prevalence of the metabolic syndrome. 155 type 2 diabetic patients and 51 non-diabetic subjects of African origin were studied. Iirrespective of gender, diabetic patients had significantly higher prevalence rate of anemia than non-diabetic subjects (p < 0.05). A high prevalence of anaemia was identified in this group of type 2 diabetic patients previously shown to have a high prevalence of the metabolic syndrome. It is therefore recommended that diagnostic laboratories in developing countries and elsewhere should include complete blood count in routine laboratory investigations in the management of diabetic patients.

Saharan dust clouds and human health in the English-speaking Caribbean: what we know and don't know. Monteil MA. Environ Geochem Health. 2008 Aug;30(4):339-43.

Dust clouds travel across the Atlantic to the Americas and the Caribbean Islands. This long-range transport of dust leads to clouds that are enriched with small particles less than 10 microm aerodynamic diameter (PM10) which can reach human airways. The dust clouds also bring pollen, microbes, insects and chemicals, all of which could potentially have a negative impact on human health. This has led to a small number of retrospective studies being conducted on the islands of Barbados and Trinidad to look at possible associations between dust cover and acute asthma admissions to Emergency Rooms. The results have been conflicting. This review examines these studies, offers possible explanations for the differences in results, and suggests that there is a need for a prospective Caribbean-wide study to assess fully any relationship between African dust clouds and human respiratory and cardiovascular diseases.

Evaluation of methods for the rapid detection of resistance to Isoniazid and Rifampicin in Mycobacterium tuberculosis isolates in the Caribbean. Akpaka PE, Baboolal S, Clarke D, Francis L, Rastogi N. J Clin Microbiol. 2008 Aug 13. [Epub ahead of print].

Rapid identification of drug-resistant strains of Mycobacterium tuberculosis is crucial for timely initiation of appropriate anti-TB therapy. Performance of Genotype MTBDRplus assay in comparison with the BACTEC 460 TB system, a gold standard culture-based method is evaluated. Genotype MTBDRplus assay was quicker and more cost-effective to detect rifampicin resistance but it was not as good for detection of isoniazid resistant strains in our setting.

Evolution and dispersal of St. Louis encephalitis virus in the Americas. Auguste AJ, Pybus OG, Carrington CV. Infect Genet Evol. 2008 Jul 29. [Epub ahead of print]

Using a Bayesian coalescent approach on a dataset of 73 envelope gene sequences we estimated substitution rates and dates of divergence for St. Louis encephalitis virus (SLEV) in the Americas. We found significant rate heterogeneity among lineages, such that "relaxed" molecular clock models were much better supported than a strict molecular clock. The mean substitution rate estimated for all SLEV was 4.1x10-4 substitutions/site /year (95% HPD 2.5-5.7)-higher than previous estimates that relied on the less well-suited strict clock. Mean substitution rates for individual lineages varied from 3.7x10-4 to 7.2x10-4 substitutions/site/year. For the first time we also assessed the magnitude and direction of viral gene flow within the Americas. The overall direction of gene flow during the period represented by the phylogeny is from South to North, and the region between 15 degrees N and 30 degrees N latitude appears to be the major source of virus for the rest of North America, which is consistent with migratory birds returning to their northern breeding grounds having acquired infection while wintering in the region of the Gulf of Mexico.

Host and vector movement affects genetic diversity and spatial structure of Buggy Creek virus (Togaviridae). Brown CR, Bomberger Brown M, Padhi A, Foster JE, Moore AT, Pfeffer M, Komar N. Mol Ecol. 2008 May;17(9):2164-73.

Determining the degree of genetic variability and spatial structure of arthropod-borne viruses (arboviruses) may help in identifying where strains that potentially cause epidemics or epizootics occur. Genetic diversity in arboviruses is assumed to reflect relative mobility of their vertebrate hosts (and invertebrate vectors), with highly mobile hosts such as birds leading to genetic similarity of viruses over large areas. There are no empirical studies that have directly related host or vector movement to virus genetic diversity and spatial structure. Using the entire E2 glycoprotein-coding region of 377 Buggy Creek virus isolates taken from cimicid swallow bugs (Oeciacus vicarius), the principal invertebrate vector for this virus, we show that genetic diversity between sampling sites could be predicted by the extent of movement by transient cliff swallows (Petrochelidon pyrrhonota) between nesting colonies where the virus and vectors occur. Pairwise F(ST) values between colony sites declined significantly with increasing likelihood of a swallow moving between those sites per 2-day interval during the summer nesting season. Sites with more bird movement between them had virus more similar genetically than did pairs of sites with limited or no bird movement. For one virus lineage, Buggy Creek virus showed greater haplotype and nucleotide diversity at sites that had high probabilities of birds moving into or through them during the summer; these sites likely accumulated haplotypes by virtue of frequent virus introductions by birds. Cliff swallows probably move Buggy Creek virus by transporting infected bugs on their feet. The results provide the first empirical demonstration that genetic structure of an arbovirus is strongly associated with host/vector movement, and suggest caution in assuming that bird-dispersed arboviruses always have low genetic differentiation across different sites.

An investigation into the prevalence of dog bites to primary school children in Trinidad. Georges K, Adesiyun A. BMC Public Health. 2008 Mar 5;8:85.

BACKGROUND: To estimate the prevalence of dog bites to primary school children between the ages of 8-12 years using a semi-structured interview process. With the increase in the pet population and popularity of dangerous breeds of dog and a high stray dog population combined with a dearth of information on the risk of dog attacks to children in Trinidad, a semi-structured interview process was used to determine risk factors associated with dog attacks. METHODS: A questionnaire survey of 1109 primary school children between the ages of 8-12 years was conducted in Trinidad from November 2002 to September 2003. The survey was conducted to determine the risk factors such as age, gender, size of dog and relationship of dog and victim, in dog bite incidents. The chi-square statistic and odds ratios were used to estimate risk factors for a bite incident. RESULTS: Twenty-eight percent of children were bitten at least once by a dog. Gender (male) and owning a dog were statistically significant risk factors (p = 0.003 and 0.008 respectively, chi2 df, 95% confidence). Most attacks occurred outside of the home (58.0%) followed by the victims' home (42.0%) and were by a dog known but not owned (54.6%) by the victim. Many victims (33.0%) were bitten without having any interaction with the dog and the majority (61.9%) of victims did not receive professional medical assistance. Overall, the lower leg or foot was most often injured (39.3%). CONCLUSION: A public educational campaign is needed on responsible pet ownership. In addition, children must be taught effective ways of avoiding attacks or reducing injury in the event of a dog attack. The Dangerous dogs Act 2000 must be proclaimed in parliament by the Government of Trinidad and Tobago to exert more pressure on pet owners to safeguard the public from the menace of dog attacks.

Adult-onset calorie restriction attenuates kainic acid excitotoxicity in the rat hippocampal slice. Youssef FF, Ramchandani J, Manswell S, McRae A. Neurosci Lett. 2008 Jan 31;431(2):118-22.

Lifelong calorie restriction is the only known intervention that has been shown to consistently increase life span and reduce the effects of aging on the brain. Given the difficulties of replicating lifelong calorie restriction within human populations, we have sought to assess the effects of short-term adult-onset calorie restriction upon acute excitotoxic insults in the rat hippocampus. Adult animals (approximately 6 months of age) underwent calorie restriction (alternate day feeding) for 7-10 weeks. Utilizing both electrophysiological and immunocytochemical techniques, we report that calorie restriction had no effect upon long-term potentiation (LTP), a measure of neuronal function. In control animals, application of kainic acid (20 microM) resulted in only 35% recovery of CA1 population spikes post-insult. However calorie-restricted animals showed significantly improved recovery after kainic acid treatment (64%). This data was supported by immunocytochemical studies which noted widespread loss of microtubule-associated protein (MAP 2) immunoreactivity in control slices following treatment with kainic acid; however MAP 2 staining was preserved in the CA1 and CA3 regions of calorie-restricted animals. Interestingly there was no significant difference in the recovery of population spikes between groups when slices were treated with N-methyl-d-aspartate (15 microM). We conclude that short-term adult-onset calorie restriction does not alter normal neuronal function and serves to protect the hippocampus from acute kainic acid excitotoxicity.

Chronic obstructive pulmonary disease is missed in asthmatics in specialty care in Trinidad, West Indies Pinto Pereira LM, Bartholomew LA, Brooks H, Lowe D, Rocke K, Rolle S, Smith J, Thekwini O, Seemungal TA, Bekele I. Int J Tuberc Lung Dis. 2007 Sep;11(9):1026-32.

Underdiagnosis of chronic obstructive pulmonary disease (COPD) in asthmatics attending specialty care in Trinidad, West Indies was studied. In a cross-sectional study, 258 asthmatics were screened for lung function measures to examine forced expiratory volume after 1 second (FEV1), forced vital capacity (FVC) and post-bronchodilator FEV1/FVC (COPD was defined as FEV1/FVC < 70%). Of 165 patients evaluated (response rate 64.0%), 53 (32.1%, 95%CI 25.0-39.2) had a study diagnosis of COPD and a mean FEV1/FVC of 60.12 +/- 1.2. Proportionally, more males had COPD (50.9%) than asthma (24.1%, P < 0.001). Patients with COPD were 10 years older than asthmatics (P < 0.001). Persons with asthma who smoked were more likely to have COPD (56.0%) (OR 3.26, 95%CI 1.36-7.80, P = 0.006). In both sexes, FEV1/FVC was lower among older people (P < 0.001), with a greater effect (OR 2.75, 95%CI 1.00-7.56, P < 0.01) seen among men in this cross-sectional study. One third of diagnosed asthmatics in specialty care also have COPD. Lung function was lower among older persons. Early spirometric evaluation of elderly asthmatics who smoke can determine the presence of COPD and facilitate appropriate management.

Plasma homocysteine is elevated in COPD patients and is related to COPD severity. Seemungal TA, Lun JC, Davis G, Neblett C, Chinyepi N, Dookhan C, Drakes S, Mandeville E, Nana F, Setlhake S, King CP, Pinto-Pereira L, Delisle J, Wilkinson TM, Wedzicha JA. Int J Chron Obstruct Pulmon Dis. 2007;2(3):313-21

Although recent studies have found that total plasma homocysteine (tHCY) and chronic obstructive pulmonary disease (COPD) are both risk factors for cardiac disease, there have been few studies of plasma homocysteine levels in COPD patients. We tested the hypothesis that total plasma homocysteine (tHCY) would be elevated in patients diagnosed with COPD compared with controls. We studied 29 COPD outpatients and 25 asymptomatic subjects (controls) over age 55 years with measurement of forced expiratory volume in one second (FEV1), forced vital capacity (FVC), St. Georges Respiratory Questionnaire (SGRQ) score, tHCY and serum C-reactive protein (sCRP). There was no difference between controls vs. COPD patients in mean age or gender but mean (SD) FEV1 was 2.25 (0.77) vs. 1.43 (0.60) L; FEV1% predicted 76.1 (17.2) vs. 49.1 (16.3) p < 0.001 in both cases. Median (IQR) tHCY was 8.22 (6.63, 9.55) in controls vs. 10.96 (7.56, 13.60) micromol/l for COPD, p = 0.006 and sCRP 0.89 (0.47, 2.55) vs. 2.05 (0.86, 6.19) mg/l, p = 0.023. tHCY(log) was also higher in (r, p) smokers (0.448, 0.001), patients with low FEV1% (-0.397, 0.003), males (0.475, < 0.001), but high SGRQ Total score (0.289, 0.034), and high sCRP (0.316, 0.038). tHCY(log) was independently related to (regression coefficient, p) sCRP(log) (0.087, 0.024), male gender (0.345, < 0.001) and presence of COPD (0.194, 0.031). Median (IQR) tHCY GOLD Stage I and II 8.05 (7.28, 11.04), GOLD Stage III and IV: 11.83 (9.30, 18.30); p = 0.023. Plasma homocysteine is significantly elevated in COPD patients relative to age and sex-matched controls and is related to serum CRP and COPD severity.

The prevalence and severity of non-carious cervical lesions in a group of patients attending a university hospital in Trinidad. Smith WA, Marchan S, Rafeek RN. Journal of Oral Rehabilitation 2007; 35(2), 128–134 doi:10.1111/j.1365-2842.2007.01763.x

Non-carious cervical lesions (NCCLs) are often encountered in clinical practice and their aetiology attributed to toothbrush abrasion, erosion and tooth flexure. This paper aims to determine the prevalence and severity of NCCLs in a sample of patients attending a university clinic in Trinidad and to investigate the relationship with medical and dental histories, oral hygiene practices, dietary habits and occlusion. Data were collected via a questionnaire and clinical examination. Odds ratios were used to determine the association of the presence of lesions and the factors examined. One hundred and fifty-six patients with a mean age of 40.6 years were examined of whom 62.2% had one or more NCCLs. Forty five per cent of the lesions were sensitive to compressed air. Younger age groups had a significantly lower correlation with the presence of NCCLs than older age groups. Other significant factors included patients who reported heartburn, gastric reflux, headaches, bruxism, sensitive teeth and swimming or had a history of broken restorations in the last year. There was also significant correlation of NCCLs in patients who brushed more than once a day or used a medium or hard toothbrush. Patients with vegetarian diets and those who reported consuming citrus fruits, soft drinks, alcohol, yoghurt and vitamin C drinks were associated with the presence of lesions. Significant associations were also found in patients with group function, faceting, clicking joints or those who wore occlusal splints.

Research Applications to Ethics Committee

Ethics Committee Application (RTF document)

Consent to Participate in Research (RTF document)