Whipple's Disease in an Afro-Caribbean National.

Whipple's disease is a rare multi-organ infectious disease caused by Tropheryma whipplei. It is fatal without treatment. We report on a 40-year old Afro-Jamaican man who presented with a six-month history of weight loss and diarrhoea. Investigations revealed iron deficiency anaemia and hypoalbuminaemia. Upper gastrointestinal endoscopy revealed white patchy lesions in the duodenum. The duodenal biopsy showed broadening and thickening of the villi by a dense infiltrate of foamy histiocytes within the lamina propria and focally extending into the attached submucosa. Periodic Acid-Schiff stains were positive. Electron microscopy was confirmatory and polymerase chain reaction testing conclusively identified the organisms as T whipplei. Antibiotic treatment resulted in resolution of symptoms. Although the diagnosis of Whipple's disease is difficult, increased awareness should lead to an increase in reported cases with the improvements in diagnostic capabilities.

Sexual difference in mercury concentrations of lake trout (Salvelinus namaycush) from Lake Ontario.

We determined total mercury (Hg) concentrations in 50 female lake trout (Salvelinus namaycush) and 69 male lake trout from Lake Ontario (Ontario, Canada and New York, United States). Results showed that, on average, males were 8% higher in Hg concentration than females in Lake Ontario. We also used bioenergetics modeling to determine whether a sexual difference in gross growth efficiency (GGE) could explain the observed sexual difference in Hg concentrations. According to the bioenergetics modeling results, male GGE was about 3% higher than female GGE, on average. Although the bioenergetics modeling could not explain the higher Hg concentrations exhibited by the males, a sexual difference in GGE remained a plausible explanation for the sexual difference in Hg concentrations of the lake trout. In an earlier study, male lake trout from Lake Ontario were found to be 22% higher in polychlorinated biphenyl (PCB) concentration than females from Lake Ontario. Thus, although males were higher in both Hg and PCB concentrations, the degree of the sexual difference in concentration varied between the two contaminants. Further research on sexual differences in Hg excretion rates and Hg direct uptake rates may be needed to resolve the disparity in results between the two contaminants.

Peutz-Jeghers syndrome.

Peutz-Jeghers Syndrome (PJS) is an autosomal dominant colonic polyposis syndrome. It is a rare condition but is of importance because of the risk of gastrointestinal as well as extraintestinal malignancies and the high penetrance in the family linkage. There has been no report of this condition in the Caribbean. We report a 32-year old male who presents with a history of rectal bleeding on a background history of having colonic polyps. Colonoscopy revealed multiple large colonic polyps with partial obstruction in the descending colon. The histology revealed hamartomatous Peutz-Jeghers polyps. Peutz-Jeghers Syndrome is an important consideration in a young patient with colonic polyps.

Sexual difference in PCB concentrations of lake trout (Salvelinus namaycush) from Lake Ontario.

We determined polychlorinated biphenyl (PCB) concentrations in 61 female lake trout (Salvelinus namaycush) and 71 male lake trout from Lake Ontario (Ontario, Canada and New York, United States). To estimate the expected change in PCB concentration due to spawning, PCB concentrations in gonads and in somatic tissue of lake trout were also determined. In addition, bioenergetics modeling was applied to investigate whether gross growth efficiency (GGE) differed between the sexes. Results showed that, on average, males were 22% higher in PCB concentration than females in Lake Ontario. Results from the PCB determinations of the gonads and somatic tissues revealed that shedding of the gametes led to 3% and 14% increases in PCB concentration for males and females, respectively. Therefore, shedding of the gametes could not explain the higher PCB concentration in male lake trout. According to the bioenergetics modeling results, GGE of males was about 2% higher than adult female GGE, on average. Thus, bioenergetics modeling could not explain the higher PCB concentrations exhibited by the males. Nevertheless, a sexual difference in GGE remained a plausible explanation for the sexual difference in PCB concentrations of the lake trout.

Juvenile polyposis syndrome.

Juvenile polyposis syndrome (JPS) is rare and is present when there are multiple juvenile polyps in the gastrointestinal tract, usually the colon. The importance of this condition is the association with the development of colorectal and upper gastrointestinal cancer at a young age. We report the case of a 21-year old male with a two-year history of intermittent rectal bleeding and anal protrusion. Colonoscopy revealed multiple pedunculated cherry red polyps mainly in the left colon. Histology confirmed juvenile polyps. Juvenile polyposis syndrome should be considered in young patients with colonic symptoms, especially rectal bleeding. It is important to distinguish between patients with JPS and patients with an isolated harmatomatous juvenile polyp.

The prevalence of Helicobacter pylori infection in patients undergoing upper gastrointestinal endoscopy in the Turks and Caicos Islands.

BACKGROUND: Helicobacter pylori infection remains a common problem and previous studies in the Caribbean revealed infection in over 50% of patients undergoing upper endoscopy. OBJECTIVE: The present study determined the prevalence of H pylori infection in patients undergoing upper gastrointestinal endoscopy in the Turks and Caicos Islands over a two- year interval. METHODS: All patients with upper gastrointestinal symptoms requiring endoscopy were evaluated clinically and H pylori testing performed histologically. RESULTS: There were 57 patients (21 males, 36 females) with a mean age of 43 years. Twenty-six patients presented with gastroesophageal reflux, 17 with upper abdominal pain, 10 with dyspepsia and 4 with upper gastrointestinal bleeding. H pylori infection was present in 24 patients (42%) and negative in 33 (58%). Upper gastrointestinal endoscopy was normal in 27 patients, 13 (54%) were H pylori positive and 14 (43%) negative. Antral gastritis was present in 13 patients, 7 (54%) were H pylori positive and 6 (46%) negative. Duodenal ulcer was present in 6 (33% H pylori positive) and gastric ulcer in 5 patients (40% H pylori positive). Distal oesophagitis was present in 5 patients (all negative for H pylori) and gastric carcinoma in 1 (H pylori positive). CONCLUSION: In patients with dyspepsia, 60% were positive for H pylori. H pylori infection was common in the patients in this study with gastrointestinal symptoms. However, the prevalence in endoscopic patients and peptic ulcer disease is lower than in other reports from the Caribbean.

Brominated and chlorinated flame retardants in Lake Ontario, Canada, lake trout (Salvelinus namaycush) between 1979 and 2004 and possible influences of food-web changes.

Concentrations of non-polybrominated diphenyl ether (PBDE) brominated (hexabromocyclododecane [HBCD], 1,2-bis[2,4,6-tribromophenoxy]ethane [BTBPE], and pentabromoethylbenzene [PEB]) and chlorinated (Dechlorane Plus [DP] as well as short- and medium-chain chlorinated paraffins [SCCP and MCCP, respectively]) flame retardants were evaluated in archived Lake Ontario, Canada, lake trout (Salvelinus namaycush) samples collected between 1979 and 2004. Polybrominated diphenyl ethers also were analyzed to provide a point of reference for comparison to previous studies. Concentrations of the dominant PBDE congeners (BDEs 28, 47, 99, 100, 153, and 154) increased significantly from 1979 until the mid-1990s, then either leveled off or decreased significantly between 1998 and 2004, a result that corresponds to those of previous studies. In contrast, BDE 209 increased approximately fourfold between 1998 and 2004. The temporal trends of the non-PBDE flame retardants varied, with sum (sigma) HBCD and DP showing significant overall decreases; BTBPE, sigmaSCCP, and sigmaMCCP showing parabolic trends; and PEB showing no overall change during the study period. Because many of the non-PBDE chemicals may be used as replacements for penta- and octa-BDE mixtures, these results will provide a baseline to evaluate future usage patterns. Possible changes in food-web structure, evaluated through stable nitrogen isotopes (delta15N), may be influencing our interpretations of contaminant trends in lake trout and are hypothesized to be partially responsible for the observed decrease in concentrations of BDEs 28, 47, 99, 100, 153, and 154 between 1998 and 2004. Retrospective analyses evaluating temporal trends in stable isotope values at the base of the food web, however, are recommended to test this hypothesis further.

Factors influencing trends of polychlorinated naphthalenes and other dioxin-like compounds in lake trout (Salvelinus namaycush) from Lake Ontario, North America (1979-2004).

Concentrations of polychlorinated naphthalenes (PCNs) were determined in archived lake trout (Salvelinus namaycush) from Lake Ontario, North America, collected between 1979 and 2004 to evaluate their temporal trends and the factors influencing their trends. Concentrations of PCNs, as well as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), and non- and mono-ortho-substituted polychlorinated biphenyls (DL-PCBs), which were measured for comparative purposes, declined by eight-, seven-, and fivefold, respectively, between 1979 and 2004. Apparent elimination rate constants (k2) were calculated as the slopes of the regression lines of concentration versus time for PCN, DL-PCB, and PCDD/F congeners to compare the rate of decrease among congeners within and between compound classes. The k2 values for PCNs that had two pairs or three adjacent carbons unsubstituted with chlorine (congeners that can be biotransformed by vertebrates) were not significantly different from zero, indicating no decline in fish. For PCN congeners having no adjacent carbons unsubstituted with chlorine, the k2 values generally increased with hydrophobicity and degree of chlorination. This pattern differed from that of PCDD/Fs and DL-PCBs and from previous findings for non-DL-PCBs, for which the rate of contaminant decline decreased with hydrophobicity, and the pattern also differed from expectations based on thermodynamics. Differences in the rate of decline of PCN congeners may be caused by changes in source or mixture formulations over time and/or metabolic dechlorination of the less stable, higher-chlorinated PCNs 73, 74, and 75 to lower-chlorinated congeners. Based on suggested dioxin toxic equivalency factors, PCN concentrations in these whole lake trout may be sufficient to trigger consumption restrictions in Ontario, Canada, and our results suggest that PCNs merit incorporation into monitoring and assessment programs.

PCB concentrations in lake trout (Salvelinus namaycush) are correlated to habitat use and lake characteristics.

This study considers the importance of lake trout habitat as a factor determining persistent organochlorine (OC) concentration. Lake trout is a stenothermal, cold water species and sensitive to hypoxia. Thus, factors such as lake depth, thermal stratification, and phosphorus enrichment may determine not only which lakes can support lake trout but may also influence among-lake variability in lake trout population characteristics including bioaccumulation of OCs. A survey of 23 lakes spanning much of the natural latitudinal distribution of lake trout provided a range of lake trout habitat to test the hypothesis that lake trout with greater access to littoral habitat for feeding will have lower concentrations of OCs than lake trout that are more restricted to pelagic habitat. Using the delta13C stable isotope signature in lake trout as an indicator of influence of benthic littoral feeding, we found a negative correlation between lipid-corrected delta13C and sigmaPCB concentrations supporting the hypothesis that increasing accessto littoral habitat results in lower OCs in lake trout. The prominence of mixotrophic phytoplankton in lakes with more contaminated lake trout indicated the pelagic microbial food web may exacerbate the biomagnification of OCs when lake trout are restricted to pelagic feeding. A model that predicted sigmaPCB in lake trout based on lake area and latitude (used as proximate variables for proportion of littoral versus pelagic habitat and accessibility to littoral habitat respectively) explained 73% of the variability in sigmaPCBs in lake trout in the 23 lakes surveyed.

Temporal trends of perfluoroalkyl compounds with isomer analysis in lake trout from Lake Ontario (1979-2004).

The temporal trends of perfluoroalkyl compounds (PFCs), including C7-C15 perfluorocarboxylates (PFCAs), perfluorosulfonates (PFSAs) and heptadecafluorooctane sulfonamide (PFOSA), were determined in lake trout collected between 1979 and 2004 from Lake Ontario. The average concentrations of total PFSAs (+/- standard error of the mean; range) increased from 20 ng g(-1) wet weight (+/- 4; 8-26) in 1979, peaked at 70 ng g(-1) (+/- 7; 58-91) in 1993, and were 46 ng g(-1) (+/- 10; 30-83) in 2004, with perfluorooctane sulfonate (PFOS) asthe most abundant PFC. The PFCAs exhibited similar temporal variation, with concentrations increasing from 1.4 ng g(-1) (+/- 0.1; 0.9-1.9) in 1979 to 9.4 ng g(1) (+/- 3.1; 3-17) in 1988, and were 6.8 ng g(-1) (+/- 1.0; 4.5-9.8) in 2004. Individual mean PFCA concentrations varied between 0.2 and 2 ng g(-1) (wet weight). Perfluorodecane sulfonate (PFDS) and PFOSA were the only compounds showing a declining trend in the past decade, after reaching a peak value in 1993. Branched C11 and C13 PFCA isomers were detected in the lake trout and confirmed in Niagara River suspended sediments, with trends in both matrices suggesting that declining emissions or use of products containing these isomers in part account for the observed PFCA trends in the mid-1990s. However, the most recent samples, comprised almost exclusively of linear isomers, indicate that current PFCA sources to Lake Ontario result from the telomerization process of linear telogens.

Bioaccumulation and trophic magnification of short- and medium-chain chlorinated paraffins in food webs from Lake Ontario and Lake Michigan.

Chlorinated paraffins (CPs) are complex mixtures of chlorinated alkanes used in a myriad of industrial applications as flame retardant plasticizers and additives. In this study, the distribution and bioaccumulation/biomagnification of short-chain CPs (C10-C13, SCCPs) and medium-chain CPs (C14-C17, MCCPs) were investigated in samples collected between 1999 and 2004 from Lake Ontario and northern Lake Michigan. Total (sigma) SCCPs and sigmaMCCPs concentrations in water from Lake Ontario were 1190 pg/L and 0.9 pg/L (data from 2004 only), respectively. CPs were also detected in invertebrates and fish from both lakes. SCCP predominated in organisms from Lake Michigan with the highest mean concentrations found in lake trout [Salvelinus namaycush, 123 +/- 35 ng/g wet weight (ww)]. In Lake Ontario, MCCPs predominated in most species with the highest levels detected in slimy sculpin (Cottus cognatus, 108 ng/g ww) and rainbow smelt (Osmerus mordax, 109 ng/g ww). Bioaccumulation and biomagnification of CPs was evaluated on an isomer basis (i.e., C10H17Cl5, C10H16Cl6, etc). Log bioaccumulation factors for lake trout (lipid based) ranged from 4.1 to 7.0 for SCCPs and 6.3 to 6.8 for MCCPs. SCCPs and MCCPs were found to biomagnify between prey and predators from both lakes with highest values observed for Diporeia-sculpin (Lake Ontario, C15Cl9 = 43; Lake Michigan, C10Cl5 = 26). Trophic magnification factors for the invertebrates-forage fish-lake trout food webs ranged from 0.41 to 2.4 for SCCPs and from 0.06 to 0.36 for MCCPs. Given the prominence of CPs, particularly in lake waters and in lower food web organisms, further investigation is needed to evaluate the magnitude of their distribution and accumulation/magnification in the Great Lakes environment.

Influence of lake characteristics on the biomagnification of persistent organic pollutants in lake trout food webs.

The biomagnification of polychlorinated biphenyls (PCBs) and major organochlorine pesticides (OCPs) was studied using lake trout (Salvelinus namaycush) and other food web organisms collected from 17 lakes in Canada and the northeastern United States between 1998 and 2001. Whole lake trout (n = 357) concentrations of the sum (Sigma) of 57 PCB congeners ranged between 1.67 and 2,890 ng/g wet weight (median 61.5 ng/g wet wt). Slimy sculpin had the highest mean concentrations of SigmaPCB of all forage fish (32-73 ng/g wet wt). Positive relationships between log (lipid wt) concentrations of PCB congener 153, PCB congener 52, p,p'-dichlorodiphenyldichloroethylene, hexachlorobenzene, cis-chlordane, trans-nonachlor, or dieldrin and trophic level (determined using stable nitrogen isotope ratios) were found for most of the 17 food webs, indicating biomagnification of these PCBs and OCPs. The p,p'-dichlorodiphenyldichloroethylene had the highest trophic magnification factors (TMFs) of the 14 individual compounds studied, averaging 4.0 +/- 1.8 across the 17 lakes, followed by trans-nonachlor (3.6 +/- 1.5) and PCB congener 153 (3.4 +/- 1.2). Average TMFs for 14 individual PCBs or OCPs were significantly correlated with log octanol-water partition coefficient, implying that the rate of accumulation along the food web is dependent on hydrophobicity and recalcitrance. Significant correlations (p < 0.05) were found between TMFs of SigmaPCBs, hexachlorobenzene, alpha-hexachlorocyclohexane, and lindane and lake area, latitude, and longitude, but not for 11 other PCBs or OCPs. Overall, the results of the present study show that biomagnification of PCBs and most OCPs, as measured by TMFs, is only weakly influenced by such factors as latitude and longitude. Exceptions are hexachlorocyclohexane isomers and hexachlorobenzene, which had generally greater TMFs in northern lakes, possibly due to lower rates of elimination and biotransformation in the food web.

Occurrence and biomagnification of polychlorinated naphthalenes and non- and mono-ortho PCBs in Lake Ontario sediment and biota.

Biota and surface sediments collected from Lake Ontario were analyzed for polychlorinated naphthalenes (PCNs) and non- and mono-ortho-substituted polychlorinated biphenyls (n/ m-o-PCBs) to compare bioaccumulation behavior of these classes of dioxin-like chemicals in a food web from the Great Lakes. Mean sigmaPCN concentrations (tri-octaCN) ranged from 14 +/- 9 pg/g in plankton to 3500 +/- 3200 pg/g (wet weight) in lake trout while sediments contained from 21 to 38 ng/g (dry weight). Principal components analysis of PCN congener patterns indicated that chlorine substitution determined which congeners favored accumulation (e.g., CN-42, -52, -60, -66, -67, and -73), while others may be subject to metabolism. The bioaccumulative congeners exhibited similar trophic magnification factors (TMFs; 1.23-1.42) and biomagnification factors (BMFs; 5.5-8.6) to the n/m-o-PCBs for the trout/weighted diet relation, although BMFs for a benthic feeding relationship (slimy sculpin/Diporeia) indicated that the n/m-o-PCBs were more bioavailablethroughthe benthic pathway. PCNs contribute significantly to the burden of dioxin-like compounds in Lake Ontario biota, contributing between 12 and 22% of total PCN + PCB TEQ in lake trout and up to 69% in benthic organisms.

The use of Lee and co-workers' index to assist a risk adjusted audit of perioperative cardiac outcome.

Lee and co-workers' revised cardiac risk index was used to study the perioperative cardiac outcome of 296 patients. The index uses a history of ischaemic heart disease, congestive cardiac failure, diabetes treated with insulin, a creatinine greater than 180 micromol/l, cerebrovascular disease and high risk surgery as the risk factors involved in predicting a perioperative cardiac event. It was derived on the basis of data from patients over the age of 50 years undergoing elective, noncardiac surgery with an expected inpatient stay of two or more days. The presence of one, two and three or more risk factors predicted a risk of a major cardiac event of 1.3% (95% confidence interval [CI] 0.7 to 2.1), 3.6% (95% CI 2.1 to 5.6) and 9% (95% CI 5.5 to 13.8) respectively in Lee's derivation group of 2,893 patients. In our audit of 296 patients we observed a cardiac event rate of 0.8% (95% CI 0 to 2.3%), 6.7% (95% CI 1.6 to 10%) and 2% (95% CI 0 to 5.9%), in patients with one, two and three or more risk factors respectively. The more frequent use of ECGs and troponin levels in the routine postoperative care of high risk patients undergoing major noncardiac surgery is recommended on the basis of the frequency of a positive result and the impact of a positive result on a patient's management.

Isomers of dechlorane plus in Lake Winnipeg and Lake Ontario food webs.

The extent of bioaccumulation of the syn- and anti-isomers of Dechlorane Plus (DP) is assessed in archived food web samples from Lake Winnipeg and Lake Ontario. Concentrations of the isomers were determined using purified analytical solutions of individual isomers as opposed to the technical mixture. The syn-isomer was consistently detected in all samples from both lakes; the anti-isomer was detected in all Lake Ontario samples, but only 45% of the samples from Lake Winnipeg. The pattern of bioaccumulation was different for the isomers in Lake Winnipeg. The anti-isomer was dominant in higher trophic level (TL) organisms like walleye [arithmetic mean +/- 1 x standard error: 730 +/- 120 pg/g, lipid weight (1w)] and goldeye (760 +/- 170 pg/g, Iw) while the syn-isomer dominated the lower TL organisms like zooplankton (550 +/- 40 pg/g, Iw) and mussels (430 +/- 140 pg/g, Iw). In Lake Ontario, the extent of bioaccumulation of the isomers and concentrations was greatest in the lower TL benthic organism, Diporeia (syn, 1307 +/- 554; and anti, 3108 +/- 898 pg/g Iw) and also high in zooplankton (syn, 719; and anti, 1332 pg/g Iw). This suggests that the isomers are bioavailable in sediment and that, despite their molecular size, diffusion from the water column into zooplankton can occur. Differences in the mean fractional abundance of the anti-isomer (mean fanti = mean concentration of the anti-isomer divided by sum of mean syn- and anti-concentrations) were pronounced in sediments between lakes (Lake Winnipeg mean fanti = 0.610, Lake Ontario mean fanti = 0.860) and the extent of enrichment (anti-) and depletion (syn-) of the isomers were more marked in Lake Winnipeg biota. There were also differences in the biomagnification potentials, as measured bythe trophic magnification factor (TMF), between the isomers in the Lake Winnipeg food web; no statistically significant TMFs for either isomer were found for the