A234 IN VITRO GUT MICROBIOME AND METABOLITE RESPONSES TO RESISTANT STARCH ARE INDIVIDUALIZED

Background

Gut microbes degrade and ferment resistant starch (RS) into metabolites that help maintain gut homeostasis. Clinical trials have evaluated RS for various health conditions, but individuals respond to RS with profound variability. The reason for this variability is unclear.

Aims

Using in vitro culturing methods and multi-omic analyses, we hypothesize that individuals will elicit variable responses to RS with respect to overall fermentation, bacterial composition, short chain acid production, and metabolite flux.

Methods

As part of an ongoing clinical trial, we have selected 4 pediatric patients with inflammatory bowel disease to better understand microbiome-RS interactions. We cultured stools anaerobically using a high-throughput platform (“RapidAIM”) with 9 different pre-digested RS. After 18-hour incubations, media supernatants were used to measure pH and perform targeted and semi-targeted metabolomic analyses with a panel of 116 compounds. Bacterial pellets were isolated for 16S rRNA gene sequencing analyses to evaluate changes in microbiome compositions. Data were analyzed with generalized linear mixed models, principal component analysis (PCA), random forest (RF) classification with feature selection, and network construction with graphical lasso.

Results

Changes in several microbiome parameters were different across individuals, including the magnitude of pH changes, metabolite signatures, and relative abundances of important bacterial taxa. Bacterial species known to degrade RS were more abundant in individuals showing stronger RS fermentation. Inter-individual discrimination was accomplished with PCA and RF, from which we could identify metabolite signatures. The robustness of microbiome networks corresponded to RS fermentation and butyrate production.

Conclusions

We report a novel perspective on how individuals respond to RS’ differently. Butyrate remains an important hub of the microbiome architecture with respect to RS fermentation. Future work will interrogate the roles of individualized metabolomic responses on host physiology. In vivo responses to RS are being evaluated in an ongoing clinical trial.

Funding Agencies

CCC, CIHRGenome Ontario, Genome Canada

A233 CHARACTERIZATION OF THE DUODENAL MICROBIOME IN PEDIATRIC CELIAC AND INFLAMMATORY BOWEL DISEASE PATIENTS

Background

Both Celiac disease (CE) and inflammatory bowel disease (IBD) are lifelong gastrointestinal tract (GIT) disorders. CE is an autoimmune disorder triggered by gluten consumption and can result in small intestine villus atrophy, crypt hyperplasia and epithelial permeability, while IBD is characterized by chronic, reoccurring inflammation and ulcers in the GIT. There is increasing evidence linking GIT microbes to both CE and IBD pathogenesis. Studies have also shown that CE patients are at increased risk of developing IBD, suggesting a possible link between these diseases. The duodenum can be affected in both CE and IBD, but it is understudied as compared to other GIT regions.

Aims

We thus aimed to characterize the duodenal microbiome of pediatric CE, IBD and control patients (n=76, 48 and 57 respectively) and hypothesized that the composition of microbes would vary between each diagnostic group.

Methods

We used mucosal luminal interface aspirates collected during upper endoscopy at the Children’s Hospital of Eastern Ontario. Metagenomic DNA was extracted from these samples and bacterial taxa was characterized by sequencing the V6 hypervariable region of the 16S rRNA gene.

Results

Control, CE, and IBD duodenal microbiotas showed no apparent differences in either α-diversity or β-diversity. However, we identified several significant differences between the relative abundances of specific taxa in these three patient groups. In particular, Atopobium parvulum was found to be enriched in Crohn’s disease samples when compared to non-IBD controls. There was also a trend for higher Bacteroides, Lactobacillus, Parabacteroides and Staphylococcus in CE patient MLI aspirates. These results are similar to what has been previously reported in CE patients. Finally, trends found in the duodenal MLI aspirates are more consistent with results previously found in the salivary microbiome in CD patients as opposed to studies of the large intestine.

Conclusions

This work provides unique insight into the microbial composition at the duodenum; a GIT region that has not been fully characterized in CE or IBD.

Funding Agencies

CIHRGenome Canada

Modeling the Effects of Future Hydroclimatic Conditions on Microbial Water Quality and Management Practices in Two Agricultural Watersheds

Anticipated future hydroclimatic changes are expected to alter the transport and survival of fecally-sourced waterborne pathogens, presenting an increased risk of recreational water quality impairments. Managing future risk requires an understanding of interactions between fecal sources, hydroclimatic conditions and best management practices (BMPs) at spatial scales relevant to decision makers. In this study we used the Hydrologic Simulation Program FORTRAN to quantify potential fecal coliform (FC - an indicator of the potential presence of pathogens) responses to a range of mid-century climate scenarios and assess different BMP scenarios (based on reduction factors) for reducing the risk of water quality impairment in two, small agricultural watersheds - the Chippewa watershed in Minnesota, and the Tye watershed in Virginia. In each watershed, simulations show a wide range of FC responses, driven largely by variability in projected future precipitation. Wetter future conditions, which drive more transport from non-point sources (e.g. manure application, livestock grazing), show increases in FC loads. Loads typically decrease under drier futures; however, higher mean FC concentrations and more recreational water quality criteria exceedances occur, likely caused by reduced flow during low-flow periods. Median changes across the ensemble generally show increases in FC load. BMPs that focus on key fecal sources (e.g., runoff from pasture, livestock defecation in streams) within a watershed can mitigate the effects of hydroclimatic change on FC loads. However, more extensive BMP implementation or improved BMP efficiency (i.e., higher FC reductions) may be needed to fully offset increases in FC load and meet water quality goals, such as total maximum daily loads and recreational water quality standards. Strategies for managing climate risk should be flexible and to the extent possible include resilient BMPs that function as designed under a range of future conditions.

A study of the hydrothermal growth of ruby

Experiments have been conducted to determine the optimum conditions for the hydrothermal growth of ruby. The solubility of corundmn in various solutions has been determined and compared with the respective growth obtained in each medium. The discrepancy between solubility and effective growth is discussed.

The need for a high degree of chemical purity has resulted in the development of platinum liners for the autoclaves. The effects of impurities and of other factors on the growth of ruby crystals have been studied. The crystal habit of hydrothermal ruby is also described.

MODELING STREAMFLOW AND WATER QUALITY SENSITIVITY TO CLIMATE CHANGE AND URBAN DEVELOPMENT IN 20 U.S. WATERSHEDS

Watershed modeling in 20 large, United States (U.S.) watersheds addresses gaps in our knowledge of streamflow, nutrient (nitrogen and phosphorus), and sediment loading sensitivity to mid-21st Century climate change and urban/residential development scenarios. Use of a consistent methodology facilitates regional scale comparisons across the study watersheds. Simulations use the Soil and Water Assessment Tool. Climate change scenarios are from the North American Regional Climate Change Assessment Program dynamically downscaled climate model output. Urban and residential development scenarios are from U.S. Environmental Protection Agency's Integrated Climate and Land Use Scenarios project. Simulations provide a plausible set of streamflow and water quality responses to mid-21st Century climate change across the U.S. Simulated changes show a general pattern of decreasing streamflow volume in the central Rockies and Southwest, and increases on the East Coast and Northern Plains. Changes in pollutant loads follow a similar pattern but with increased variability. Ensemble mean results suggest that by the mid-21st Century, statistically significant changes in streamflow and total suspended solids loads (relative to baseline conditions) are possible in roughly 30-40% of study watersheds. These proportions increase to around 60% for total phosphorus and total nitrogen loads. Projected urban/residential development, and watershed responses to development, are small at the large spatial scale of modeling in this study.

Development of UK recommendations on treatment for post-surgical erectile dysfunction

AIM

To develop a management strategy (rehabilitation programme) for postsurgical erectile dysfunction (ED) among men experiencing ED associated with treatment of prostate, bladder or rectal cancer that is suitable for use in a UK NHS healthcare context.

METHODS

PubMed literature searches of ED management together with a survey of 13 experts in the management of ED from across the UK were conducted.

RESULTS

Data from 37 articles and completed questionnaires were collated. The results discussed in this study demonstrate improved objective and subjective clinical outcomes for physical parameters, sexual satisfaction, and rates of both spontaneous erections and those associated with ED treatment strategies.

CONCLUSION

Based on the literature and survey analysis, recommendations are proposed for the standardisation of management strategies employed for postsurgical ED.

Toolbox: Female sexual problems: sexual pain and sexual fears

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Risk factors for treatment outcome of suspected microbial keratitis. Ofloxacin Study Group

BACKGROUND

Primary treatment for suspected microbial keratitis is generally successful. Although risks such as contact lens use are well recognised as causative factors for microbial keratitis, little is known about the risk factors that influence treatment outcome. The present study evaluates the risk factors assessed at diagnosis as prognostic indicators of primary treatment failure.

METHODS

Patients were prospectively enrolled in the ofloxacin treatment trial and data concerning symptoms, treatments, past and concurrent eye disease were collected along with the measurement of corneal ulcer size at the slit lamp. All patients were scraped for microbiological investigation, and treated with either ofloxacin (0. 3%) or standard therapy of fortified cefuroxime and gentamicin drops. Treatment success was complete healing of the ulcer with zero dimensions of the epithelial defect within 2 weeks of start of treatment. The important prognostic indicators were selected by comparison among those who failed treatment, had delayed healing, or were culture positive with other patients using univariate and stratified analysis. These were then used in a Poisson model for multiple regression analysis to estimate the relative risk of the main prognostic variables.

RESULTS

Of the 118 patients enrolled in the study, 14 were identified as primary treatment failures, 17 had slow healing, and 15 indolent ulcers. There were 49 culture positive patients. The multivariate analysis identified that large culture positive ulcers in patients 60 years or older had 5.5 times the risk of primary treatment failure (p<0.001). Significant predictors of slow healing were previous ocular disease and a positive culture; significant predictors of indolent ulceration were previous ocular disease and steroid use at diagnosis; the main predictor of a culture positive result was ulcer size.

CONCLUSIONS

Elderly patients with large ulcers were more likely to be culture positive, fail primary therapy, and require surgical intervention. A positive microbial culture provided prognostic information regardless of the organism isolated. However, this information was of less value for those with small ulcers and for younger patients.

Toolbox: Female sexual problems: loss of desire

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Chorioretinal lesions in patients and carriers of chronic granulomatous disease

OBJECTIVE

To investigate the frequency of retinal lesions in patients with chronic granulomatous disease (CGD) and to seek such lesions in carriers.

STUDY DESIGN

Seventy-four individuals from 33 families were recruited; 38 had CGD (30 X-linked and 8 autosomal recessive inheritance). All participants (including 33 control subjects) underwent measurement of visual acuity, anterior segment examination by slit lamp, and dilated funduscopy.

RESULTS

Nine of 38 (23.7%) of the affected children had chorioretinal lesions compared with 0 of 33 control subjects. All 9 were known to have X-linked CGD and absent gp91(phox). The "typical" retinal abnormality consisted of "punched out" chorioretinal lesions associated with pigment clumping lying along major retinal vessels. Unexpectedly, 3 XL-CGD asymptomatic carriers also had typical chorioretinal lesions.

CONCLUSION

Retinal lesions are relatively common in patients with XL-CGD and may interfere with vision and thus should be sought in such patients.

The effects of physical exercise on patients with Crohn's disease

OBJECTIVE

Despite the suggested benefits of exercise training in the prevention and management of chronic diseases, few data exist regarding the safety of exercise in Crohn's disease and whether or not exercise may have beneficial effects on patients' health. We performed a pilot study to evaluate the effects of regular light-intensity exercise on sedentary patients with Crohn's disease.

METHODS

Sedentary patients with inactive or mildly active Crohn's disease were eligible for the study. A thrice-weekly, 12-wk walking program was supervised, although if subjects could not attend the group walking sessions they were allowed to walk on their own. Logbooks of performance were maintained, and individual exercise heart rate goals were established. Measures performed at baseline and at study completion included the Inflammatory Bowel Disease Stress Index, the Inflammatory Bowel Disease Quality of Life Score, the Harvey and Bradshaw Simple Index, the Canadian Aerobic Fitness Test, VO2 Max, and body mass index (BMI).

RESULTS

Twelve subjects completed the 12-wk exercise program. Subjects walked an average of 2.9 sessions/wk, at an average of 32.6 min/session, and for an average distance of 3.5 km/session. Statistically significant improvements at study end were seen by all measures, with a trend toward reduction in BMI. No patient's disease flared during the study.

CONCLUSIONS

Sedentary patients with Crohn's disease can tolerate low-intensity exercise of moderate duration without an exacerbation of symptoms. Twelve weeks of walking was adequate to elicit psychological and physical improvements and did not adversely affect disease activity.

Effects of six weeks of chronic ethanol administration on the behavioral outcome of rats after lateral fluid percussion brain injury

This study examined the effects of 6 weeks of chronic ethanol administration on the behavioral outcome in rats after lateral fluid percussion (FP) brain injury. Rats were given either an ethanol liquid diet (ethanol diet-groups) or a pair-fed isocaloric sucrose control diet (control diet groups) for 6 weeks. After 6 weeks, the ethanol diet was discontinued for the ethanol diet rats and they were then given the control sucrose diet for 2 days. During those 2 days, the rats were trained to perform a beam-walking task and subjected to either lateral FP brain injury of low to moderate severity (1.8 atm) or to sham operation. In both the control diet and the ethanol diet groups, lateral FP brain injury caused beam-walking impairment on days 1 and 2 and spatial learning disability on days 7 and 8 after brain injury. There were no significant differences in beam-walking performance and spatial learning disability between brain injured animals from the control and ethanol diet groups. However, a trend towards greater behavioral deficits was observed in brain injured animals in the ethanol diet group. Histologic analysis of both diet groups after behavioral assessment revealed comparable ipsilateral cortical damage and observable CA3 neuronal loss in the ipsilateral hippocampus. These results only suggest that chronic ethanol administration, longer than six weeks of administration, may worsen behavioral outcome following lateral FP brain injury. For more significant behavioral and/or morphological change to occur, we would suggest that the duration of chronic ethanol administration must be increased.

Effects of six weeks of chronic ethanol administration on lactic acid accumulation and high energy phosphate levels after experimental brain injury in rats

The effects of 6 weeks of chronic ethanol administration on the lateral fluid percussion (FP) brain injury-induced regional accumulation of lactate and on the levels of total high-energy phosphates were examined in rats. In both the chronic ethanol diet (ethanol diet) and pair-fed isocaloric sucrose control diet (control diet) groups, tissue concentrations of lactate were elevated in the cortices and hippocampi of both the ipsilateral and contralateral hemispheres at 5 min after brain injury. In both diet groups, concentrations of lactate were elevated only in the injured left cortex and the ipsilateral hippocampus at 20 min after FP brain injury. No significant differences were found in the levels of lactate in the cortices and hippocampi of sham animals and brain-injured animals between the ethanol and control diet groups at 5 min and 20 min after injury. In the ethanol and control diet groups, tissue concentrations of total high-energy phosphates (ATP + PCr) were not affected in the cortices and hippocampi at 5 min and 20 min after lateral FP brain injury. No significant differences were found in the levels of total high-energy phosphates in the cortices and hippocampi of the sham and brain-injured animals between the ethanol and control diet groups at 5 min and 20 min after injury. Histologic studies revealed a similar extent of damage in the cortex and in the CA3 region of the ipsilateral hippocampus in both diet groups at 14 days after lateral FP brain injury. These findings suggest that 6 weeks of chronic ethanol administration does not alter brain injury-induced accumulation of lactate, levels of total high energy phosphates, and extent of morphological damage.

Phlebitis associated with peripheral cannulae

Observation of the cannula is imperative in detecting early signs of phlebitis. To maintain high standards of cannula care, nurse education is important, along with regular auditing of the incidence of phlebitis. Careful consideration should be given to the size of cannula used and the position in which it is sited. Use of Vialon cannulae may be preferable to Teflon.

Common upper-extremity injuries

In the daily practice of family medicine, injuries to the upper extremity are frequently encountered. Most of these injuries can by easily treated by the primary care physician who has an understanding of the joint anatomy and treatment principles. Some injuries, however, may appear relatively minor, yet require prompt referral for surgical care. We reviewed the pathoanatomy, historical and physical examination findings, and treatment of the more common injuries to the hand, wrist, elbow, and shoulder.

Hearing loss in myotonic dystrophy

Seventeen of 25 patients with myotonic dystrophy had moderate to severe hearing loss, usually sensorineural, that was identified by routine audiometric screening and was treatable in some patients. Further testing failed to reveal a single pathophysiological process.

A focus of mucocutaneous leishmaniasis in Três Braços, Bahia, Brazil: characterization and identification of Leishmania stocks isolated from man and dogs

The characterization and identification to species and subspecies of 20 stocks of Leishmania isolated from the region of Três Braços, Bahia, Brazil, are described: 17 stocks were from patients and three from dogs. The following techniques were used (i) biological (growth in culture, hamster tissues and phlebotomine gut), (ii) biochemical (isoenzyme and kinetoplast DNA analysis) and (iii) immunological (using monoclonal antibodies). All except two stocks belong to the L. braziliensis complex. One of these two corresponded to L. mexicana amazonensis but the other, while clearly in the mexicana complex, showed slight differences from the L. mexicana amazonensis reference strain on isoenzyme analysis. Two stocks from different lesions in the same patient and with different growth characteristics in hamster tissues were both identified as L. braziliensis braziliensis. All the fully characterized stocks of the L. braziliensis complex were identified as L. braziliensis braziliensis. L. braziliensis guyanensis was not identified. Dog and human stocks of L. braziliensis braziliensis were indistinguishable. From these findings and other evidence, L. braziliensis braziliensis seems to be the predominant species transmitted in Três Braços.