Faculty of Medical Sciences

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Global asymptotic stability of solutions of cubic stochastic difference equations
(2004-07-12)
Global almost sure asymptotic stability of solutions of some nonlinear stochastic difference equations with cubic-type main part in their drift and diffusive part driven by square-integrable martingale differences is proven under appropriate conditions in and#8477;1. As an application of this result, the asymptotic stability of stochastic numerical methods, such as partially drift-implicit and#952;-methods with variable step sizes for ordinary stochastic differential equations driven by standard Wiener processes, is discussed.
Identification of a novel cytosolic aldehyde dehydrogenase allele, ALDHIAI*4
(2009-07-01) Moore, Shelley M; Liang, Tiebing; Graves, Tamara J; McCall, Kevin M; Carr, Lucinda G; Ehlers, Cindy L
Abstract This paper reports the identification of a novel cytosolic aldehyde dehydrogenase 1 (ALDHIAI) allele. One hundred and sixty-two Indo-Trinidadian and 85 Afro-Trinidadian individuals were genotyped. A novel ALDHIAI allele, ALDHIAI*4, was identified in an Indo-Trinidadian alcoholic with an A inserted at position -554 relative to the translational start site, +1. It was concluded that a wider cross-section of individuals needs to be evaluated in order to determine the representative frequency of the allele, and to see if it is associated with risk of alcoholism.
The Jamaica asthma and allergies national prevalence survey: rationale and methods
(2010-04-03) Kahwa, Eulalia K; Younger, Novie O; Wint, Yvonne B; Waldron, Norman K; Hewitt, Hermi H; Knight-Madden, Jennifer M; Bailey, Kay A; Edwards, Nancy C; Talabere, Laurel R; Lewis-Bell, Karen N
Abstract Background Asthma is a significant public health problem in the Caribbean. Prevalence surveys using standardized measures of asthma provide valid prevalence estimates to facilitate regional and international comparisons and monitoring of trends. This paper describes methods used in the Jamaica Asthma and Allergies National Prevalence Survey, challenges associated with this survey and strategies used to overcome these challenges. Methods/Design An island wide, cross-sectional, community-based survey of asthma, asthma symptoms and allergies was done among adults and children using the European Community Respiratory Health Survey Questionnaire for adults and the International Study of Asthma and Allergies in Children. Stratified multi-stage cluster sampling was used to select 2, 163 adults aged 18 years and older and 2, 017 children aged 2-17 years for the survey. The Kish selection table was used to select one adult and one child per household. Data analysis accounted for sampling design and prevalence estimates were weighted to produce national estimates. Discussion The Jamaica Asthma and Allergies National Prevalence Survey is the first population- based survey in the Caribbean to determine the prevalence of asthma and allergies both in adults and children using standardized methods. With response rates exceeding 80% in both groups, this approach facilitated cost-effective gathering of high quality asthma prevalence data that will facilitate international and regional comparison and monitoring of asthma prevalence trends. Another unique feature of this study was the partnership with the Ministry of Health in Jamaica, which ensured the collection of data relevant for decision-making to facilitate the uptake of research evidence. The findings of this study will provide important data on the burden of asthma and allergies in Jamaica and contribute to evidence-informed planning of comprehensive asthma management and education programs.
Are primary care practitioners in Barbados following hypertension guidelines? - A chart audit.
(2010-11-22) Adams, O PETER; Carter, Anne O
Abstract Background About 55% of the population 40 to 80 years of age in Barbados is hypertensive. The quality of hypertension primary care compared to available practice guidelines is uncertain. Findings Charts of hypertensive and diabetic patients were randomly sampled at all public and 20 private sector primary care clinics. Charts of all hypertensive patients and#8805; 40 years of age were then selected and processes of care and blood pressure (BP) maintenance andlt; 140/90 documented. 343 charts of hypertensive patients (170 public, and 173 private) were audited. Patients had the following characteristics: mean age 64 years, female gender 63%, mean duration of diagnosis 9.1 years, and diabetes diagnosed 58%. Patients had an average of 4.7 clinic visits per year, 70% were prescribed a thiazide diuretic, 42% a calcium channel blocker, 40% an angiotensin receptor blocker, and 19% a beta blocker. Public patients compared to private patients were more likely to be female (73% vs. 52%, p andlt; 0.01); have a longer duration of diagnosis (11.7 vs. 6.5 years, p andlt; 0.01), and more clinic visits per year (5.0 vs. 4.5, p andlt; 0.01). Over a 2 year period, the proportion of charts with the following recorded at least once was: BP 98%, weight 80%, total cholesterol 71%, urine tested for albumin 67%, serum creatinine 59%, dietary advice 55%, lipid profile 48%, exercise advice 45%, fasting blood glucose for non-diabetics 39%, dietician referral 21%, tobacco advice 17%, retinal examination 16%, body mass index 1%, and waist circumference 0%. Public patients were more likely to have recorded: weight (92% vs. 68%, p = andlt; 0.01); tests for total cholesterol (77% vs. 67%, p = 0.04), albuminuria (77% vs. 58%, p = andlt; 0.01), serum creatinine (75% vs. 43%, p andlt; 0.01), and fasting blood glucose for non-diabetics (49% vs. 30%, p = 0.02); dietician referral (34% vs. 9%, p andlt; 0.01), and tobacco advice (24% vs. 10%, p andlt; 0.01). Most (92%) diastolic BP readings ended in 0 or 5 (72% ended in 0). At the last visit 36% of patients had a BP andlt; 140/90 mmHg. Conclusions Improvements are needed in following guidelines for basic interventions such as body mass assessment, accurate BP measurement, use of thiazide diuretics and lifestyle advice. BP control is inadequate.
Diabetes and Hypertension guidelines and the Primary Health Care Practitioner in Barbados: Knowledge, Attitudes, Practices and Barriers - A focus group study
(2010-12-03) Adams, O PETER; Carter, Anne O
Abstract Background Audits have shown numerous deficiencies in the quality of hypertension and diabetes primary care in Barbados, despite distribution of regional guidelines. This study aimed to evaluate the knowledge, attitudes and practices, and the barriers faced by primary care practitioners in Barbados concerning the recommendations of available diabetes and hypertension guidelines. Methods Focus groups using a moderator's manual were conducted at all 8 public sector polyclinics, and 5 sessions were held for private practitioners. Results Polyclinic sessions were attended by 63 persons (17 physicians, 34 nurses, 3 dieticians, 3 podiatrists, 5 pharmacists, and 1 other), and private sector sessions by 20 persons (12 physicians, 1 nurse, 3 dieticians, 2 podiatrists and 2 pharmacists). Practitioners generally thought they gave a good quality of care. Commonwealth Caribbean Medical Research Council 1995 diabetes and 1998 hypertension guidelines, and the Ministry of Health 2001 diabetes protocol had been seen by 38%, 32% and 78% respectively of polyclinic practitioners, 67%, 83%, and 33% of private physicians, and 25%, 0% and 38% of non-physician private practitioners. Current guidelines were considered by some to be outdated, unavailable, difficult to remember and lacking in advice to tackle barriers. Practitioners thought that guidelines should be circulated widely, promoted with repeated educational sessions, and kept short. Patient oriented versions of the guidelines were welcomed. Patient factors causing barriers to ideal outcome included denial and fear of stigma; financial resources to access an appropriate diet, exercise and monitoring equipment; confusion over medication regimens, not valuing free medication, belief in alternative medicines, and being unable to change habits. System barriers included lack of access to blood investigations, clinic equipment and medication; the lack of human resources in polyclinics; and an uncoordinated team approach. Patients faced cultural barriers with regards to meals, exercise, appropriate body size, footwear, medication taking, and taking responsibility for one's health; and difficulty getting time off work to attend clinic. Conclusions Guidelines need to be promoted repeatedly, and implemented with strategies to overcome barriers. Their development and implementation must be guided by input from all providers on the primary health care team.
Highlighting the genetic and epidemiologic disparities of Mycobacterium tuberculosis epidemic in 12 Caribbean territories in a first global study
(BioMed Central Ltd, 2011-01-10) Millet, Julie
Tuberculosis (TB) in the Caribbean remains a significant health issue with many countries exceeding the WHO target of 5 cases / 100,000 populations. As a developing nation, many of these Caribbean countries face serious challenges in the diagnosis, treatment, care and management of patients with tuberculosis. In light of the current problems facing the tuberculosis programs in the Caribbean, there is a need for studies to be conducted so as to better understand the epidemiology of this disease in such a heterogeneous setting. This investigation describes a first global molecular epidemiological study on 480 clinical M. tuberculosis isolates from as many patients, collected in 12 territories of the Caribbean: Bahamas, Barbados, Belize, Dominica, Guyana, Jamaica, St. Kitts and Nevis, St. Lucia, St. Vincent and the Grenadines, Suriname, Trinidad and Tobago, Turks and Caicos. Analysis of and#8220;de-identifiedand#8221; patient data showed that TB cases more often concerned males (male to female sex-ratio, 3.1), and persons within age group 25-45 years. The rate of TB/HIV coinfection was unexpectedly high with rates ranging from 44.4% in Guyana, 42.9% in Bahamas, 30.6% in Trinidad and Tobago, 21.4% in Suriname, 14.3% in Barbados and 13.5% in Jamaica. The highest rate of drug-resistant TB was observed in Guyana (27.8%, among which 76% were multidrug-resistant). Spoligotyping generated a total of 104 distinct patterns for the 480 isolates studied; 49 patterns containing 425 isolates (88.5%) corresponded to clustered strains (2-93 isolates per cluster), while the remaining 55 patterns corresponded to unclustered strains (11.5%). A comparison of the spoligotypes with the SITVIT2 global database showed that the isolates belonged to the following predominant genotypic lineages: the ill-defined T lineage (31.0%), East-African Indian (EAI, 19.0%), Latin American and Mediterranean (LAM, 10.4%), the X clade (8.3%), Haarlem (5.8%), and Beijing (3.5%). The diversity of strains circulating in the Caribbean essentially represented their colonial past (clades of European descent such as Haarlem, and X clades) as well as population movements (EAI, Beijing). Lineages characteristic of the Indian subcontinent (East- African-Indian, Central-Asian) were seen in Trinidad and Tobago, Guyana, and Suriname where there is a large population of East Indians brought during the indentureship period, after slavery was abolished. Lastly, a peculiar local evolution of M. tuberculosis strains in Trinidad and Tobago was evidenced with the exclusive local emergence of a specific TB clone (named SIT566, belonging most probably to the X clade), which resulted in 56% of all TB cases.
Portal vein thrombosis following laparoscopic cholecystectomy complicated by dengue viral infection: a case report
(2011-03-30) Dan, Dilip; King, Kevin; Seetahal, Shiva; Naraynsingh, Vijay; Hariharan, Seetharaman
Abstract Introduction Portal vein thrombosis is an uncommon post-operative complication following abdominal surgery. Although therapeutic anticoagulation is recommended, this treatment may be questionable when the patient has an associated bleeding diathesis. Case presentation We report a case of a 63-year-old woman of Asian Indian ethnicity who developed portal vein thrombosis following an uneventful laparoscopic cholecystectomy for symptomatic gallstones. Her condition was further complicated by dengue viral infection in the post-operative period, with thrombocytopenia immediately preceding the diagnosis of portal vein thrombosis. The etiological connections between dengue viral infection with thrombocytopenia, laparoscopic cholecystectomy, portal vein thrombosis as well as the treatment dilemmas posed in treating a patient with portal vein thrombosis with a bleeding diathesis are discussed. Conclusion When portal vein thrombosis occurs in patients with contraindications to anticoagulation, there is a role for initial conservative management without aggressive anticoagulation therapy and such patients must be approached on an individualized basis.
Methicillin sensitive Staphylococcus auras producing Panton-Valentine leukocidin toxin in Trinidad and Tobago: a case report
(2011-04-20) Akpaka, Patrick E; Monecke, Stefan; Swanston, William H; Rao, AV C; Schulz, Renee; Levett, Paul N
Abstract Introduction Certain Staphylococcus aureus strains produce Panton-Valentine leukocidin, a toxin that lyses white blood cells causing extensive tissue necrosis and chronic, recurrent or severe infection. This report documents a confirmed case of methicillin-sensitive Staphylococcus aureus strain harboring Panton-Valentine leukocidin genes from Trinidad and Tobago. To the best of our knowledge, this is the first time that such a case has been identified and reported from this country. Case presentation A 13-year-old Trinidadian boy of African descent presented with upper respiratory symptoms and gastroenteritis-like syptoms. About two weeks later he was re-admitted to our hospital complaining of pain and weakness affecting his left leg, where he had received an intramuscular injection of an anti-emetic drug. He deteriorated and developed septic arthritis, necrotizing fasciitis and septic shock with acute respiratory distress syndrome, leading to death within 48 hours of admission despite intensive care treatment. The infection was caused by S. aureus. Bacterial isolates from specimens recovered from our patient before and after his death were analyzed using microarray DNA analysis and spa typing, and the results revealed that the S. aureus isolates belonged to clonal complex 8, were methicillin-susceptible and positive for Panton-Valentine leukocidin. An autopsy revealed multi-organ failure and histological tissue stains of several organs were also performed and showed involvement of his lungs, liver, kidneys and thymus, which showed Hassal's corpuscles. Conclusion Rapid identification of Panton-Valentine leukocidin in methicillin-sensitive S. aureus isolates causing severe infections is necessary so as not to miss their potentially devastating consequences. Early feedback from the clinical laboratories is crucial.
Asking the right questions: developing evidence-based strategies for treating HIV in women and children
(2011-05-25) Abdool Karim, Quarraisha; Banegura, Anchilla; Cahn, Pedro; Christie, Celia DC; Dintruff, Robert; Distel, Manuel; Hankins, Catherine; Hellmann, Nicholas; Katabira, Elly; Lehrman, Sandra; Montaner, Julio; Purdon, Scott; Rooney, James F; Wood, Robin; Heidari, Shirin
Abstract In July 2010, the World Health Organization (WHO) issued formal revisions of its guidelines on the use of highly active antiretroviral therapy for HIV. The new guidelines greatly expand eligibility for treatment of adults and children, as well as for pregnant women seeking prophylaxis for vertical HIV transmission. WHO's new recommendations bring the guidelines closer to practices in developed countries, and its shift to earlier treatment alone will increase the number of treatment-eligible people by 50% or more. Scaling up access to HIV treatment is revealing important gaps in our understanding of how best to provide for all those in need. This knowledge gap is especially significant in developing countries, where women and children comprise a majority of those living with HIV infection. Given the magnitude and significance of these populations, the International AIDS Society, through its Industry Liaison Forum, prioritized HIV treatment and prophylaxis of women and children. In March 2010, the International AIDS Society and 15 partners launched a Consensus Statement outlining priority areas in which a relative lack of knowledge impedes delivery of optimal prevention of mother to child transmission (PMTCT) and treatment to women and children. The Consensus Statement, "Asking the Right Questions: Advancing an HIV Research Agenda for Women and Children", makes a special appeal for a more gender-sensitive approach to HIV research at all stages, from conception to design and implementation. It particularly emphasizes research to enhance the understanding of sex-based differences and paediatric needs in treatment uptake and response. In addition to clinical issues, the statement focuses on programmatic research that facilitates access and adherence to antiretroviral regimens. Better coordination of HIV management with sexual and reproductive healthcare delivery is one such approach. We discuss here our knowledge gaps concerning effective, safe PMTCT and treatment for women and children in light of the expansion envisioned by WHO's revised guidelines. The guideline's new goals present an opportunity for advancing the women and children's agenda outlined in the Consensus Statement.
Aortic Dissection at the University Hospital of the West Indies: A 20-year Clinicopathological Study of Autopsy Cases
(2011-09-09) Coard, Kathleen CM
Abstract Background An autopsy study of aortic dissection (AD) at our institution was previously reported. In the approximately 20 years since then, however, many aspects of diagnosis and treatment of this disease have changed, with a fall in mortality reported in many centers around the world. An impression amongst our pathologists that, there might be an increase in the prevalence of AD in the autopsy service at our hospital, since that earlier report, led to this repeated study, in an attempt to validate that notion. We also sought to identify any changes in clinicopathological features between the two series or any occurring during this study period itself. Findings All cases of AD identified at autopsy, during the 20-year period since the conclusion of the last study, were collected and pertinent clinical and pathological data were analyzed and compared, both within the two decades of this study period and against the results of the last study. Fifty-six cases comprised this study group including 36 males and 20 females, with a mean age of 63.9 years. There were, more patients in the second decade (n = 33; 59%) compared with the first decade (n = 23; 41%). Hypertension as a risk factor was identified in 52 (93%) cases and rupture occurred in 49 (88%) cases. A clinical diagnosis of AD was considered prior to surgery or autopsy in 25 (45%) cases overall, more during the second decade. Surgery was attempted in 25% of all cases with an increase in the second decade compared with the first. Conclusions Compared with the earlier review, a variety of changes in the profile of patients with AD in the autopsy service has been noted, including a reversal in the female predominance seen previously. Other observations include an increase in cases where the correct clinical diagnosis was considered and in which surgical treatment was attempted, changes also evident when the second decade of the present study was compared with the earlier decade. Overall, there were many positive trends. However, areas that could still be improved include an increased index of suspicion for the diagnosis of AD and perhaps in the initiation of treatment, earlier, in those cases where the correct diagnosis was considered.
Bone mineral density in Jamaican men on androgen deprivation therapy for prostate cancer
(2011-09-23)
Abstract Background Androgen deprivation therapy (ADT) has been reported to reduce the bone mineral density (BMD) in men with prostate cancer (CaP). However, Afro-Caribbeans are under-represented in most studies. The aim was to determine the effect of androgen deprivation therapy (ADT) on the bone mineral density (BMD) of men with prostate cancer in Jamaica. Methods The study consisted of 346 Jamaican men, over 40 years of age: 133 ADT treated CaP cases (group 1), 43 hormone-naand#239;ve CaP controls (group 2) and 170 hormone naand#239;ve controls without CaP (group 3). Exclusion criteria included metastatic disease, bisphosphonate therapy or metabolic disease affecting BMD. BMD was measured with a calcaneal ultrasound and expressed in S.D. units relative to young adult men (T score), according to the World Health Organization definition. Patient weight, height and BMI were assessed. Results Mean and#177; sd, age of patients in group 1 (75and#177; 7.4 yrs) was significantly greater than groups 2 and 3 (67 and#177; 8.1 yrs; 65and#177;12.0 yrs). There was no significant difference in weight and BMI between the 3 groups. . The types of ADT (% of cases, median duration in months with IQR) included LHRH (Luteinizing hormone releasing hormone) analogues (28.6%, 17.9, IQR 20.4), oestrogens (9.8%, 60.5, IQR 45.6) anti-androgens (11.3%, 3.3, IQR 15.2) and orchiectomy (15.7%, 43.4, IQR 63.9). Unadjusted t score of group 1, mean and#177; sd, (-1.6and#177; 1.5) was significantly less than group 2 (-0.9and#177;1.1) and group 3 (-0.7and#177;1.4), p andlt;0.001. Ninety three (69.9%), 20 (45%) and 75 (42%) of patients in groups 1, 2 and 3 respectively were classified as either osteopenic or osteoporotic (pandlt;0.001). Adjusting for age, there was a significant difference in t scores between groups 1 and 2 as well as between groups 1 and 3 (pandlt;0.001). Compared with oestrogen therapy and adjusting for duration of therapy, the odds of low bone mineral density (osteopenia or osteoporosis) with LHRH analogue was 4.5 (95%CI, 14.3 to 3.4); with anti-androgens was 5.9 (95%CI, 32.7 to 5); with orchiectomy was 7.3 (95%CI, 30 to 5.8) and multiple drugs was 9.2 ((95%CI, 31 to 7.1). Conclusions ADT is associated with lower BMD in Jamaican men on hormonal therapy for prostate cancer.
Applying the Stages of Change model to Type 2 diabetes care in Trinidad: A randomised trial.
(2011-10-11) Partapsingh, V A; Maharaj, R G; Rawlins, J M
Abstract Objective To improve glycaemic control among Type 2 diabetics using patient-physician consultations guided by the Stages of Change (SOC) model. Design and Methods A randomised trial was conducted. After ensuring concealment of allocation, Type 2 diabetics were randomly assigned to receive the intervention or the control. The intervention consisted of identifying each patient's Stage of Change for managing their diabetes by diet, exercise and medications, and applying personalised, stage-specific care during the patient-physician consultations based on the SOC model. Patients in the control group received routine care. The variables of interest were effect on glycaemic control (measured by the difference in HbA1c levels) and patients' readiness to change (measured by identifying patients' SOC for managing their diabetes by diet, exercise and medications). Results Participants were primarily over age 50, male and Indo-Trinidadian. Most had received only a primary school education and over 65% had a monthly income of $320 USD/month or less. Sixty-one Type 2 diabetics participated in each arm. Three patients were lost to follow-up in the intervention arm. After 48 weeks, there was an overall increase in HbA1c of 0.52% (SE 0.17) and 1.09% (SE 0.18) for both the intervention and control groups respectively. There was a relative reduction in HbA1c of 0.57% (95% CI 0.07, 1.07) with the intervention group compared to the control (p = 0.025). For exercise and diet there was an overall tendency for participants in the intervention arm to move to a more favourable SOC, but little change was noted with regards medication use. Conclusions The result suggests a tendency to a worsening of glycaemic control in this population despite adopting more favourable SOC for diet and exercise. We hypothesized that harsh social conditions prevailing at the time of the study overrode the clinical intervention.
Knowledge, attitudes, practices, and barriers reported by patients receiving diabetes and hypertension primary health care in Barbados: a focus group study
(2011-12-02) Adams, O Peter; Carter, Anne O
Abstract Background Deficiencies in the quality of diabetes and hypertension primary care and outcomes have been documented in Barbados. This study aimed to explore the knowledge, attitudes and practices, and the barriers faced by people with diabetes and hypertension in Barbados that might contribute to these deficiencies. Methods Five structured focus groups were conducted for randomly selected people with diabetes and hypertension. Results Twenty-one patients (5 diabetic, 5 hypertensive, and 11 with both diseases) with a mean age of 59 years attended 5 focus group sessions. Patient factors that affected care included the difficulty in maintaining behaviour change. Practitioner factors included not considering the "whole person" and patient expectations, and not showing enough respect for patients. Health care system factors revolved around the amount of time spent accessing care because of long waiting times in public sector clinics and pharmacies. Society related barriers included the high cost and limited availability of appropriate food, the availability of exercise facilities, stigma of disease and difficulty taking time off work. Attendees were not familiar with guidelines for diabetes and hypertension management, but welcomed a patient version detailing a place to record results, the frequency of tests, and blood pressure and blood glucose targets. Appropriate education from practitioners during consultations, while waiting in clinic, through support and education groups, and for the general public through the schools, mass media and billboards were recommended. Conclusions Primary care providers should take a more patient centred approach to the care of those with diabetes and hypertension. The care system should provide better service by reducing waiting times. Patient self-management could be encouraged by a patient version of care guidelines and greater educational efforts.
Protocol for the modeling the epidemiologic transition study: a longitudinal observational study of energy balance and change in body weight, diabetes and cardiovascular disease risk
(2011-12-14) Luke, Amy; Bovet, Pascal; Forrester, Terrence E; Lambert, Estelle V; Plange-Rhule, Jacob; Schoeller, Dale A; Dugas, Lara R; Durazo-Arvizu, Ramon A; Shoham, David; Cooper, Richard S; Brage, Soren; Ekelund, Ulf; Steyn, Nelia
Abstract Background The prevalence of obesity has increased in societies of all socio-cultural backgrounds. To date, guidelines set forward to prevent obesity have universally emphasized optimal levels of physical activity. However there are few empirical data to support the assertion that low levels of energy expenditure in activity is a causal factor in the current obesity epidemic are very limited. Methods/Design The Modeling the Epidemiologic Transition Study (METS) is a cohort study designed to assess the association between physical activity levels and relative weight, weight gain and diabetes and cardiovascular disease risk in five population-based samples at different stages of economic development. Twenty-five hundred young adults, ages 25-45, were enrolled in the study; 500 from sites in Ghana, South Africa, Seychelles, Jamaica and the United States. At baseline, physical activity levels were assessed using accelerometry and a questionnaire in all participants and by doubly labeled water in a subsample of 75 per site. We assessed dietary intake using two separate 24-hour recalls, body composition using bioelectrical impedance analysis, and health history, social and economic indicators by questionnaire. Blood pressure was measured and blood samples collected for measurement of lipids, glucose, insulin and adipokines. Full examination including physical activity using accelerometry, anthropometric data and fasting glucose will take place at 12 and 24 months. The distribution of the main variables and the associations between physical activity, independent of energy intake, glucose metabolism and anthropometric measures will be assessed using cross-section and longitudinal analysis within and between sites. Discussion METS will provide insight on the relative contribution of physical activity and diet to excess weight, age-related weight gain and incident glucose impairment in five populations' samples of young adults at different stages of economic development. These data should be useful for the development of empirically-based public health policy aimed at the prevention of obesity and associated chronic diseases.
Distended bladder presenting with constipation and venous obstruction: a case report
(2012-01-24) Sharma, Anu; Naraynsingh, Vijay
Abstract Introduction A distended urinary bladder has been known to cause venous obstruction or rarely bowel obstruction. We report the first case in the literature in which urinary bladder distension presented with both venous obstruction and constipation. This is an unusual presentation of urinary bladder distension and serves to broaden our differential diagnoses for a patient with clinical venous obstruction. Case presentation An 83-year-old man of African descent presented with constipation and bilateral lower limb edema. A huge abdominal mass was evident which was a large, distended urinary bladder confirmed by computed tomography. Promptly after urethral catheterization, both constipation and lower limb edema resolved. Conclusions To the best of our knowledge distended urinary bladder causing both constipation and lower limb edema has never previously been reported. Analysis of the literature revealed several factors resulting in the patient's presentation. A high level of suspicion for urinary bladder distension must be maintained for prompt diagnosis and to avoid improper management.
Does insulin resistance co-exist with glucocorticoid resistance in the Metabolic Syndrome? Studies comparing skin sensitivity to glucocorticoids in individuals with and without acanthosis nigricans
(2012-03-30) Teelucksingh, Surujpal; Jaimungal, Sarada; Pinto Pereira, Lexley; Seemungal, Terence; Nayak, Shivananda
Abstract Background The metabolic syndrome is associated with increased risk for both diabetes and coronary artery disease, which insulin resistance alone does not satisfactorily explain. We propose an additional and complementary underlying mechanism of glucocorticoid resistance. Results Using acanthosis nigricans (AN) and skin vasoconstrictor (SVC) response to topically applied beclomethasone dipropionate as markers of insulin and glucocorticoid resistance, respectively, we compared anthropometric, biochemical, pro-inflammatory markers and the SVC response in subjects with AN in two studies: STUDY 1 was used to compare subjects with AN (Grade 4, n = 32), with those without AN (n = 68) while STUDY 2 compared these responses among a cross-section of diabetic patients (n = 109) with varying grades of AN (grade 0, n = 30; grade 1, n = 24; grade 2, n = 18; grade 3, n = 25; grade 4, n = 12). Findings In both studies there was an inverse relationship between AN Grade 4 and the SVC response, (P andlt; 0.001). In STUDY 1, AN Grade 4 was associated with age, waist circumference, BMI, fasting blood glucose, plasma lipids and hs-CRP (P andlt; 0.05). SVC was an independent predictor of CRP and those with combined AN and a negative SVC response, CRP levels were highest. In Study 2 when the SVC response in subjects with type 2 diabetes mellitus with varying degrees of AN was studied, it showed that for any degree of AN, the SVC response is more likely to be negative and was independent of gender and ethnicity. Conclusion An absent SVC response represents a new biomarker for the metabolic syndrome and the exaggerated inflammatory response, which characterizes the metabolic syndrome, may be an outcome of deficient glucocorticoid action in vascular tissue.
Cytotoxic and potent CYP1 inhibitors from the marine algae Cymopolia barbata
(2012-06-11) Badal, Simone; Gallimore, Winklet; Huang, George; Tzeng, Tzuen-Rong J; Delgoda, Rupika
Abstract Background Extracts from the marine algae Cymopolia barbata have previously shown promising pharmacological activity including antifungal, antitumor, antimicrobial, and antimutagenic properties. Even though extracts have demonstrated such bioactivity, isolated ingredients responsible for such bioactivity remain unspecified. In this study, we describe chemical characterization and evaluations of biological activity of prenylated bromohydroquinones (PBQ) isolated from the marine algae C. barbata for their cytotoxic and chemopreventive potential. Methods The impact of PBQs on the viability of cell lines (MCF-7, HT29, HepG, and CCD18 Co) was evaluated using the MTS assay. In addition, their inhibitory impact on the activities of heterologously expressed cytochrome P450 (CYP) enzymes (CYP1A1, CYP1A2, CYP1B1, CYP2C19, CYP2D6, and CYP3A4) was evaluated using a fluorescent assay. Results 7-Hydroxycymopochromanone (PBQ1) and 7-hydroxycymopolone (PBQ2) were isolated using liquid and column chromatography, identified using 1and#8201;H and 13and#8201;C NMR spectra and compared with the spectra of previously isolated PBQs. PBQ2 selectively impacted the viability of HT29, colon cancer cells with similar potency to the known chemotherapeutic drug, fluorouracil (IC50, 19.82and#8201;and#177;and#8201;0.46 and#956;M compared to 23.50and#8201;and#177;and#8201;1.12 and#956;M, respectively) with impact toward normal colon cells also being comparable (55.65and#8201;and#177;and#8201;3.28 compared to 55.51and#8201;and#177;and#8201;3.71 and#956;M, respectively), while PBQ1 had no impact on these cells. Both PBQs had potent inhibition against the activities of CYP1A1 and CYP1B1, the latter which is known to be a universal marker for cancer and a target for drug discovery. Inhibitors of CYP1 enzymes by virtue of the prevention of activation of carcinogens such as benzo-a-pyrene have drawn attention as potential chemopreventors. PBQ2 potently inhibited the activity of CYP1B1 (IC50 0.14and#8201;and#177;and#8201;0.04 and#956;M), while both PBQ1 and PBQ2 potently inhibited the activity of CYP1A1 (IC50s of 0.39and#8201;and#177;and#8201;0.05 and#956;M and 0.93and#8201;and#177;and#8201;0.26 and#956;M, respectively). Further characterizations showed partial noncompetitive enzyme kinetics for PBQ2 with CYP1B1 with a K i of 4.7 and#215; 10and#8211;3and#8201;and#177;and#8201;5.1 and#215; 10and#8211;4 and#956;M and uncompetitive kinetics with CYP1A1 (K i = 0.84and#8201;and#177;and#8201;0.07 and#956;M); while PBQ1 displayed partial non competitive enzyme kinetics with CYP1A1 (K i of 3.07and#8201;and#177;and#8201;0.69 and#956;M), noncompetitive kinetics with CYP1A2 (K i and#8201;=and#8201;9.16and#8201;and#177;and#8201;4.68 and#956;M) and uncompetitive kinetics with CYP1B1 (K i = 0.26and#8201;and#177;and#8201;0.03 and#956;M) . Conclusions We report for the first time, two isolated ingredients from C. barbata, PBQ1 and PBQ2, that show potential as valuable chemotherapeutic compounds. A hydroxyl moiety resident in PBQ2 appears to be critical for selectivity and potency against the cancer colon cells, HT29, in comparison to the three other malignant cell lines studied. PBQs also show potency against the activities of CYP1 enzyme which may be a lead in chemoprevention. This study, the first on isolates from these marine algae, exemplifies the value of searching within nature for unique structural motifs that can display multiple biological activities.
A comparison of real-time PCR and reverse line blot hybridization in detecting feline haemoplasmas of domestic cats and an analysis of risk factors associated with haemoplasma infections
(2012-07-02) Georges, Karla; Ezeokoli, Chuckwudozi; Auguste, Tennille; Seepersad, Nisshi; Pottinger, Akua; Sparagano, Olivier; Tasker, Séverine
Abstract Background Three species of feline haemoplasma are recognised: Mycoplasma haemofelis (Mhf), and#8216;Candidatus Mycoplasma haemominutumand#8217; (CMhm) and and#8216;Candidatus Mycoplasma turicensis (CMt). This study compared a reverse line blot hybridization (RLB) assay for simultaneous detection of Mhf, CMhm with three separate quantitative real-time polymerase chain reaction (qPCR) assays used for diagnosis of Mhf, CMhm and CMt. The RLB and qPCR assays were applied to DNA extracted from blood samples collected from 154 cats from Trinidad and Tobago. Results CMhm and Mhf DNA were detected using both RLB and qPCR. CMt DNA was detected by qPCR only. Comparing RLB and qPCR for the detection of CMhm DNA, 40 (26.3%) and 48 (31.6%) cats, respectively, were positive. The difference was more marked for Mhf, with RLB detecting a total of only 11 (7.2%) positive cats whereas qPCR detected 41 (27.0%) positive cats. Using qPCR as a gold standard, haemoplasma infected cats were more likely to be retrovirus positive (ORand#8201;=and#8201;5.68, Pand#8201;=and#8201;0.02) and older (median age 5.5 years), than non-infected cats. In addition, CMhm positive cats were more likely to be male (ORand#8201;=and#8201;3.4, Pand#8201;=and#8201;0.04). Conclusions Overall the qPCR was more sensitive than RLB. In addition, age (median 5.5 years) and retrovirus positivity were risk factors for infection with the feline haemoplasmas in this study population. Further studies on feline haemoplasma infections in cats are needed to determine the significance of detecting small amounts of haemoplasma DNA, feline retrovirus infection and other associated risk factors on the clinical manifestation of disease.
Is the Advanced Pediatric Life Support formula used to calculate weight-for-age applicable to a Trinidadian population?
(2012-08-02) Ali, Khalid; Sammy, Ian; Nunes, Paula
Abstract Background In paediatric emergency medicine, estimation of weight in ill children can be performed in a variety of ways. Calculation using the and#8216;APLSand#8217; formula (weightand#8201;=and#8201;[ageand#8201;+and#8201;4] and#215; 2) is one very common method. Studies on its validity in developed countries suggest that it tends to under-estimate the weight of children, potentially leading to errors in drug and fluid administration. The formula is not validated in Trinidad and Tobago, where it is routinely used to calculate weight in paediatric resuscitation. Methods Over a six-week period in January 2009, all children one to five years old presenting to the Emergency Department were weighed. Their measured weights were compared to their estimated weights as calculated using the APLS formula, the Luscombe and Owens formula and a and#8220;best fitand#8221; formula derived (then simplified) from linear regression analysis of the measured weights. Results The APLS formula underestimated weight in all age groups with a mean difference of and#8722;1.4and#8201;kg (95% limits of agreement 5.0 to and#8722;7.8). The Luscombe and Owens formula was more accurate in predicting weight than the APLS formula, with a mean difference of and#8722;0.4and#8201;kg (95% limits of agreement 6.9 to and#8722;6.1%). Using linear regression analysis, and simplifying the derived equation, the best formula to describe weight and age was (weightand#8201;=and#8201;[2.5 x age]and#8201;+and#8201;8). The percentage of children whose actual weight fell within 10% of the calculated weights using any of the three formulae was not significantly different. Conclusions The APLS formula slightly underestimates the weights of children in Trinidad, although this is less than in similar studies in developed countries. Both the Luscombe and Owens formula and the formula derived from the results of this study give a better estimate of the measured weight of children in Trinidad. However, the accuracy and precision of all three formulae were not significantly different from each other. It is recommended that the APLS formula should continue to be used to estimate the weight of children in resuscitation situations in Trinidad, as it is well known, easy to calculate and widely taught in this setting.
Oral healthcare of preschool children in Trinidad: a qualitative study of parents and caregivers
(2012-08-03) Naidu, Rahul; Nunn, June; Forde, Maarit
Abstract Background Little is known about oral health in early childhood in the West Indies or the views and experiences of caregivers about preventive oral care and dental attendance The aims of this study were to explore and understand parents and caregiversand#8217; experience of oral healthcare for their preschool aged children and how, within their own social context, this may have shaped their oral health attitudes and behaviours. These data can be used to inform oral health promotion strategies for this age group. Method After ethical approval, a qualitative study was undertaken using a focus group approach with a purposive sample of parents and caregivers of preschool children in central Trinidad.Group discussions were initiated by use of a topic guide. Audio recording and field notes from the three focus groups, with a total of 18 participants, were transcribed and analysed using a thematic approach. Results Despite some ambivalence toward the importance of the primary teeth, the role of fluoride and confusion about when to take a child for their first dental visit, most participants understood the need to ensure good oral hygiene and dietary habits for their child. Problems expressed included, overcoming their own negative experiences of dentistry, which along with finding affordable and suitable dental clinics, affected their attitude to taking their child for a dental visit. There was difficulty in establishing good brushing routines and controlling sweet snacking in the face of many other responsibilities at home. Lack of availability of paediatric dental services locally and information on oral health care were also highlighted. Many expressed a need for more contact with dental professionals in non-clinic settings, for oral health care advice and guidance. Conclusion Parents and caregivers in this qualitative study showed generally positive attitudes towards oral health but appear to have encountered several barriers and challenges to achieving ideal preventive care for their child, with respect to healthy diet, good oral hygiene and dental attendance. Oral health promotion should include effective dissemination of oral health information, more practical health advice and greater access to dental care for families with preschool children.

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