Siddharth Singh - Academia.edu (original) (raw)

Papers by Siddharth Singh

Scientific Reports, 2022

Crop residue management is a massive problem in the agriculture sector. Agricultural waste in the... more Crop residue management is a massive problem in the agriculture sector. Agricultural waste in the form of stubble which is usually burnt in the farm fields, causes severe air pollution and poses a threat to the environment. The present study investigates the addition of agro-waste (rice straw) in gypsum hollow-core blocks for partition walls. Various compositions of agro-waste-based gypsum samples have been studied for compressive strength, thermal, sound absorption, sound transmission loss, and fire-resistant properties. The addition of rice straw in gypsum reduces the density and compressive strength of the test sample, thus making it lightweight for non-load bearing wall application. The thermal conductivity of the rice straw added gypsum samples show a decrease in thermal conductivity from 0.2 to 0.11 W/m K. Acoustic properties viz., noise reduction coefficient (NRC) increases from 25 to 45% with increase in rice straw addition and a decreasing trend in sound transmission class ...

This proposal outlines the design of a comparative analysis of the four institutional repository ... more This proposal outlines the design of a comparative analysis of the four institutional repository software packages that were represented at the 4th International Conference on Open Repositories held in 2009 in Atlanta, Georgia: EPrints, DSpace, Fedora and Zentity (The 4th International Conference on Open Repositories website, https://or09.library.gatech.edu). The study includes 23 qualitative and quantitative measures taken from default installations of the four repositories on a benchmark machine with a predefined base collection. The repositories are also being assessed on the execution of four common workflows: consume, submit, accept, and batch. A panel of external reviewers provided feedback on the design of the study and its evaluative criteria, and input is currently being solicited from the developer and user communities of each repository in order to refine the criteria, measures, data collection methods, and analyses. The aim is to produce a holistic evaluation that will d...

Journal of Comparative and Physiological Psychology, 1959

... MOWRER, 0. H., & AIKKN, EG Contiguity vs. drive-reduction... more ... MOWRER, 0. H., & AIKKN, EG Contiguity vs. drive-reduction in conditioned and unconditioned stim-ulus. Amei: J. Psycliol. 1954, 67, 26-38. SINGH, SD Conditioned emotional response in the rat: II. Effect of stimulant and depressant drugs. Ada. Psycliol., in press. ...

Hepatology (Baltimore, Md.), Jan 13, 2015

Most individuals with chronic hepatitis B viral (HBV) infection acquired the infection around the... more Most individuals with chronic hepatitis B viral (HBV) infection acquired the infection around the time of birth or during early childhood. We aimed to synthesize evidence regarding the effectiveness of antiviral therapy in the management of chronic HBV infection in children. We conducted a comprehensive search of multiple databases from 1988 to December 2, 2014, for studies that enrolled children (<18 years) with chronic HBV infection treated with antiviral therapy. We included observational studies and randomized controlled trials (RCTs). Two independent reviewers selected studies and extracted data. In the 14 included studies, two cohort studies showed no significant reduction in the already low risk of hepatocellular carcinoma or cirrhosis and 12 RCTs reported intermediate outcomes. In RCTs with posttreatment follow-up…

Mayo Clinic proceedings, Jan 8, 2015

To estimate the overall risk of cancer in a population-based cohort of patients with inflammatory... more To estimate the overall risk of cancer in a population-based cohort of patients with inflammatory bowel disease (IBD) and how IBD-related medications modify this risk. We identified all incident cancers (excluding nonmelanoma skin cancer) after IBD diagnosis in a cohort of 839 patients diagnosed as having IBD from January 1, 1940, through December 31, 2004, in Olmsted County, Minnesota, and followed up for a median 18 years through December 31, 2011 (122 patients taking biologic agents at last follow-up). We calculated standardized incidence ratios (SIRs) with 95% CIs of all cancers and compared cancer risk in patients treated with immunomodulators (IMMs) and biologics with that of patients not exposed to these medications, using an incidence rate ratio (IRR). One hundred nine patients developed 135 cancers. The 10-year cumulative probability of cancer was 3.8%. Patients with Crohn disease (SIR, 1.6; 95% CI, 1.2-2.1) but not ulcerative colitis (SIR, 1.1; 95% CI, 0.8-1.4) had an incr...

The American journal of gastroenterology, 2013

Several preclinical and observational studies have shown that anti-diabetic medications (ADMs) ca... more Several preclinical and observational studies have shown that anti-diabetic medications (ADMs) can modify the risk of hepatocellular cancer (HCC) in patients with diabetes mellitus (DM). We performed a systematic review and meta-analyses of studies evaluating the effect of metformin, thiazolidinediones (TZDs), sulfonylureas, and/or insulin on the risk of HCC. We conducted a systematic search of Medline, EMBASE, and Web of Science up to August 2012. Studies were included if they (1) evaluated and clearly defined exposure to metformin, TZDs, sulfonylureas, and/or insulin, (2) reported HCC outcomes in patients with DM, and (3) reported relative risks or odds ratio (OR) or provided data for their estimation. Summary OR estimates with 95% confidence intervals (CIs) were estimated using the random-effects model. Ten studies reporting 22,650 cases of HCC in 334,307 patients with type 2 DM were included in the analysis. Meta-analysis of observational studies showed a 50% reduction in HCC in...

The American journal of gastroenterology, 2013

Several preclinical and observational studies have shown that anti-diabetic medications (ADMs) ma... more Several preclinical and observational studies have shown that anti-diabetic medications (ADMs) may modify the risk of pancreatic cancer (PaC). We performed a systematic review and meta-analysis evaluating the effect of metformin, sulfonylureas (SUs), thiazolidinediones (TZDs), and insulin on the risk of PaC in patients with diabetes mellitus (DM). We conducted a systematic search of Medline, EMBASE, and Web of Science, up to June 2012, and published abstracts from major gastroenterology and oncology meetings from 2003 to 2012. Studies were included if they (1) evaluated and clearly defined exposure to metformin, SU, TZDs, and/or insulin, (2) reported PaC outcomes in patients with DM and (3) reported relative risks or odds ratio (OR) or provided data for their estimation. Summary OR estimates with 95% confidence intervals (CIs) were estimated using the random-effects model. Eleven studies (6 cohort, 3 case-control, and 2 randomized controlled trials (RCTs)) reported 1770 cases of PaC...

Optics express, Jan 7, 2014

A novel wavelength combiner using non-uniform refractive index distribution within a multimode in... more A novel wavelength combiner using non-uniform refractive index distribution within a multimode interference device is proposed and simulated. The refractive index step creates separate localized modes with different effective refractive indices and two modes are strongly excited which form the basis of an interferometer. We applied the concept to 1.30/1.31 μm and 1.31/1.55 μm wavelength combiners on an InP substrate. The lengths of the devices are 1272 μm and 484 μm with simulated insertion losses of 0.6 dB and 0.67 dB respectively.

Gastroenterology clinics of North America, 2014

Anti-tumor necrosis factor-α (TNF) agents, including infliximab, adalimumab, and certolizumab peg... more Anti-tumor necrosis factor-α (TNF) agents, including infliximab, adalimumab, and certolizumab pegol, are effective medications for the management of moderate to severe Crohn disease (CD). They are effective in inducing and maintaining clinical remission, inducing mucosal healing, improving quality of life, and reducing the risk of hospitalization and surgery in adult and pediatric patients with CD. Future research into comparative effectiveness of different agents, as well as better understanding of predictors of response, is warranted to allow optimization of therapeutic response.

Nature reviews. Gastroenterology & hepatology, 2015

IBD is an established risk factor for venous thromboembolism. In the past few years, studies have... more IBD is an established risk factor for venous thromboembolism. In the past few years, studies have suggested that patients with IBD might also be at an increased risk of coronary heart disease and stroke. The increased risk is thought to be similar to the level of risk seen in patients with other chronic systemic inflammatory diseases such as rheumatoid arthritis. The risk of developing these conditions is particularly increased in young adults with IBD, and more so in women than in men. Conventional cardiovascular risk factors are not over-represented in patients with IBD, so the increased risk could be attributable to inflammation-mediated atherosclerosis. Patients with IBD often have premature atherosclerosis and have biochemical and genetic markers similar to those seen in patients with atherosclerotic cardiovascular disease. The role of chronic inflammation in IBD-associated cardiovascular disease merits further evaluation. Particular attention should be given to the increased r...

Gastrointestinal Endoscopy, 2014

Annals of internal medicine, Jan 6, 2015

The relative efficacy of available treatments of knee osteoarthritis (OA) must be determined for ... more The relative efficacy of available treatments of knee osteoarthritis (OA) must be determined for rational treatment algorithms to be formulated. To examine the efficacy of treatments of primary knee OA using a network meta-analysis design, which estimates relative effects of all treatments against each other. MEDLINE, EMBASE, Web of Science, Google Scholar, Cochrane Central Register of Controlled Trials from inception through 15 August 2014, and unpublished data. Randomized trials of adults with knee OA comparing 2 or more of the following: acetaminophen, diclofenac, ibuprofen, naproxen, celecoxib, intra-articular (IA) corticosteroids, IA hyaluronic acid, oral placebo, and IA placebo. Two reviewers independently abstracted study data and assessed study quality. Standardized mean differences were calculated for pain, function, and stiffness at 3-month follow-up. Network meta-analysis was performed using a Bayesian random-effects model; 137 studies comprising 33 243 participants were ...

Scandinavian Journal of Infectious Diseases, 2011

We present the case of an international traveller who was eventually diagnosed with amoebiasis an... more We present the case of an international traveller who was eventually diagnosed with amoebiasis and autosomal dominant polycystic kidney disease (ADPKD) after she presented with recurring fevers. The patient was also diagnosed with non-amoebic bacterial hepatitis. Positron emission tomography (PET) can play an important role in locating the source of infection in patients with ADPKD when hepatic or renal infection is suspected. It can also be used to document clinical resolution of infection in difficult cases. Hepatic parenchymal infections in ADPKD patients may warrant a prolonged course of rotating antibiotics.

Journal of Periodontology, 1996

It is our central hypothesis that periodontal diseases, which are chronic Gram-negative infection... more It is our central hypothesis that periodontal diseases, which are chronic Gram-negative infections, represent a previously unrecognized risk factor for atherosclerosis and thromboembolic events. Previous studies have demonstrated an association between periodontal disease severity and risk of coronary heart disease and stroke. We hypothesize that this association may be due to an underlying inflammatory response trait, which places an individual at high risk for developing both periodontal disease and atherosclerosis. We further suggest that periodontal disease, once established, provides a biological burden of endotoxin (lipopolysaccharide) and inflammatory cytokines (especially TxA2, IL-1 beta, PGE2, and TNF-alpha) which serve to initiate and exacerbate atherogenesis and thromboembolic events. A cohort study was conducted using combined data from the Normative Aging Study and the Dental Longitudinal Study sponsored by the United States Department of Veterans Affairs. Mean bone loss scores and worst probing pocket depth scores per tooth were measured on 1,147 men during 1968 to 1971. Information gathered during follow-up examinations showed that 207 men developed coronary heart disease (CHD), 59 died of CHD, and 40 had strokes. Incidence odds ratios adjusted for established cardiovascular risk factors were 1.5, 1.9, and 2.8 for bone loss and total CHD, fatal CHD, and stroke, respectively. Levels of bone loss and cumulative incidence of total CHD and fatal CHD indicated a biologic gradient between severity of exposure and occurrence of disease.

Journal of Clinical Microbiology, 2012

The contribution of environmental surface contamination with pathogenic organisms to the developm... more The contribution of environmental surface contamination with pathogenic organisms to the development of health care-associated infections (HAI) has not been well defined. The microbial burden (MB) associated with commonly touched surfaces in intensive care units (ICUs) was determined by sampling six objects in 16 rooms in ICUs in three hospitals over 43 months. At month 23, copper-alloy surfaces, with inherent antimicrobial properties, were installed onto six monitored objects in 8 of 16 rooms, and the effect that this application had on the intrinsic MB present on the six objects was assessed. Census continued in rooms with and without copper for an additional 21 months. In concert with routine infection control practices, the average MB found for the six objects assessed in the clinical environment during the preintervention phase was 28 times higher (6,985 CFU/100 cm 2 ; n = 3,977 objects sampled) than levels proposed as benign immediately after terminal cleaning (<250 CFU/100...

Journal of Clinical Gastroenterology, 2010

Constipation is one of the most common digestive problems in North America with significant psych... more Constipation is one of the most common digestive problems in North America with significant psychosocioeconomic implications. It is caused by either a primary disorder of colonic and anorectal function or by many secondary conditions such as constipating drugs, metabolic disorders and other colorectal problems. Given the heterogeneity of problems that cause constipation, defining the underlying pathophysiology is increasingly being recognized as a key step toward optimal management. Colonic manometry with sensation and tone assessment (barostat) and anorectal manometry with rectal sensation and compliance assessment and balloon expulsion test can provide a comprehensive evaluation of colonic and anorectal sensorimotor function and facilitate a diagnosis of slow transit constipation, dyssynergic defecation or irritable bowel syndrome, or an overlap of these disorders. This review provides a critical appraisal of the role of manometric techniques toward augmenting our understanding of colonic and anorectal physiology, both in health and constipation and discussing their clinical utility in the diagnosis and management of chronic constipation.

International Journal of Cardiology, 2013

Gastroenterology Clinics of North America, 2010

Chronic constipation (CC) affects 20% of the population, 1 has a significant effect on quality of... more Chronic constipation (CC) affects 20% of the population, 1 has a significant effect on quality of life and use of health care resources including drug therapy, 2 and causes significant psychological distress. 3 Almost 85% of physician visits for constipation result in a prescription for laxatives, 2 and $821 million is spent annually on over-thecounter laxatives. 3 Constipation comprises many symptoms such as hard stools, excessive straining, infrequent bowel movement, feeling of incomplete evacuation, and abdominal bloating; its treatment largely encompasses relieving these symptoms and restoring a normal bowel habit. An essential component of management of CC is identification and management of secondary causes such as drug-induced constipation, for example opioid-induced constipation or an obstructive lesion in the colon, the management of which usually results in resolution of constipation. If excluded, primary constipation consists of 3 overlapping subtypes 3,4 : (1) slow transit constipation, characterized by prolonged transit through the colon owing to a primary dysfunction of colonic smooth muscle (myopathy) or its nerve innervations (neuropathy)-this usually requires aggressive medical management but may need surgical intervention 3 ; (2) dyssynergic defecation, a disorder of impaired abdominal, rectoanal, and pelvic floor muscle coordination that requires both medical management and biofeedback treatment 3 ; (3) constipation-predominant irritable bowel syndrome (IBS-C), seen in patients in whom abdominal pain or discomfort is the predominant symptom with usually normal colonic transit and pelvic floor function, and thought to be a result of an interaction of genetic, environmental, social, biologic, Conflict of interest: None.

Scientific Reports, 2022

Crop residue management is a massive problem in the agriculture sector. Agricultural waste in the... more Crop residue management is a massive problem in the agriculture sector. Agricultural waste in the form of stubble which is usually burnt in the farm fields, causes severe air pollution and poses a threat to the environment. The present study investigates the addition of agro-waste (rice straw) in gypsum hollow-core blocks for partition walls. Various compositions of agro-waste-based gypsum samples have been studied for compressive strength, thermal, sound absorption, sound transmission loss, and fire-resistant properties. The addition of rice straw in gypsum reduces the density and compressive strength of the test sample, thus making it lightweight for non-load bearing wall application. The thermal conductivity of the rice straw added gypsum samples show a decrease in thermal conductivity from 0.2 to 0.11 W/m K. Acoustic properties viz., noise reduction coefficient (NRC) increases from 25 to 45% with increase in rice straw addition and a decreasing trend in sound transmission class ...

This proposal outlines the design of a comparative analysis of the four institutional repository ... more This proposal outlines the design of a comparative analysis of the four institutional repository software packages that were represented at the 4th International Conference on Open Repositories held in 2009 in Atlanta, Georgia: EPrints, DSpace, Fedora and Zentity (The 4th International Conference on Open Repositories website, https://or09.library.gatech.edu). The study includes 23 qualitative and quantitative measures taken from default installations of the four repositories on a benchmark machine with a predefined base collection. The repositories are also being assessed on the execution of four common workflows: consume, submit, accept, and batch. A panel of external reviewers provided feedback on the design of the study and its evaluative criteria, and input is currently being solicited from the developer and user communities of each repository in order to refine the criteria, measures, data collection methods, and analyses. The aim is to produce a holistic evaluation that will d...

Journal of Comparative and Physiological Psychology, 1959

... MOWRER, 0. H., &amp;amp;amp;amp;amp;amp;amp;amp; AIKKN, EG Contiguity vs. drive-reduction... more ... MOWRER, 0. H., &amp;amp;amp;amp;amp;amp;amp;amp; AIKKN, EG Contiguity vs. drive-reduction in conditioned and unconditioned stim-ulus. Amei: J. Psycliol. 1954, 67, 26-38. SINGH, SD Conditioned emotional response in the rat: II. Effect of stimulant and depressant drugs. Ada. Psycliol., in press. ...

Hepatology (Baltimore, Md.), Jan 13, 2015

Most individuals with chronic hepatitis B viral (HBV) infection acquired the infection around the... more Most individuals with chronic hepatitis B viral (HBV) infection acquired the infection around the time of birth or during early childhood. We aimed to synthesize evidence regarding the effectiveness of antiviral therapy in the management of chronic HBV infection in children. We conducted a comprehensive search of multiple databases from 1988 to December 2, 2014, for studies that enrolled children (<18 years) with chronic HBV infection treated with antiviral therapy. We included observational studies and randomized controlled trials (RCTs). Two independent reviewers selected studies and extracted data. In the 14 included studies, two cohort studies showed no significant reduction in the already low risk of hepatocellular carcinoma or cirrhosis and 12 RCTs reported intermediate outcomes. In RCTs with posttreatment follow-up…

Mayo Clinic proceedings, Jan 8, 2015

To estimate the overall risk of cancer in a population-based cohort of patients with inflammatory... more To estimate the overall risk of cancer in a population-based cohort of patients with inflammatory bowel disease (IBD) and how IBD-related medications modify this risk. We identified all incident cancers (excluding nonmelanoma skin cancer) after IBD diagnosis in a cohort of 839 patients diagnosed as having IBD from January 1, 1940, through December 31, 2004, in Olmsted County, Minnesota, and followed up for a median 18 years through December 31, 2011 (122 patients taking biologic agents at last follow-up). We calculated standardized incidence ratios (SIRs) with 95% CIs of all cancers and compared cancer risk in patients treated with immunomodulators (IMMs) and biologics with that of patients not exposed to these medications, using an incidence rate ratio (IRR). One hundred nine patients developed 135 cancers. The 10-year cumulative probability of cancer was 3.8%. Patients with Crohn disease (SIR, 1.6; 95% CI, 1.2-2.1) but not ulcerative colitis (SIR, 1.1; 95% CI, 0.8-1.4) had an incr...

The American journal of gastroenterology, 2013

Several preclinical and observational studies have shown that anti-diabetic medications (ADMs) ca... more Several preclinical and observational studies have shown that anti-diabetic medications (ADMs) can modify the risk of hepatocellular cancer (HCC) in patients with diabetes mellitus (DM). We performed a systematic review and meta-analyses of studies evaluating the effect of metformin, thiazolidinediones (TZDs), sulfonylureas, and/or insulin on the risk of HCC. We conducted a systematic search of Medline, EMBASE, and Web of Science up to August 2012. Studies were included if they (1) evaluated and clearly defined exposure to metformin, TZDs, sulfonylureas, and/or insulin, (2) reported HCC outcomes in patients with DM, and (3) reported relative risks or odds ratio (OR) or provided data for their estimation. Summary OR estimates with 95% confidence intervals (CIs) were estimated using the random-effects model. Ten studies reporting 22,650 cases of HCC in 334,307 patients with type 2 DM were included in the analysis. Meta-analysis of observational studies showed a 50% reduction in HCC in...

The American journal of gastroenterology, 2013

Several preclinical and observational studies have shown that anti-diabetic medications (ADMs) ma... more Several preclinical and observational studies have shown that anti-diabetic medications (ADMs) may modify the risk of pancreatic cancer (PaC). We performed a systematic review and meta-analysis evaluating the effect of metformin, sulfonylureas (SUs), thiazolidinediones (TZDs), and insulin on the risk of PaC in patients with diabetes mellitus (DM). We conducted a systematic search of Medline, EMBASE, and Web of Science, up to June 2012, and published abstracts from major gastroenterology and oncology meetings from 2003 to 2012. Studies were included if they (1) evaluated and clearly defined exposure to metformin, SU, TZDs, and/or insulin, (2) reported PaC outcomes in patients with DM and (3) reported relative risks or odds ratio (OR) or provided data for their estimation. Summary OR estimates with 95% confidence intervals (CIs) were estimated using the random-effects model. Eleven studies (6 cohort, 3 case-control, and 2 randomized controlled trials (RCTs)) reported 1770 cases of PaC...

Optics express, Jan 7, 2014

A novel wavelength combiner using non-uniform refractive index distribution within a multimode in... more A novel wavelength combiner using non-uniform refractive index distribution within a multimode interference device is proposed and simulated. The refractive index step creates separate localized modes with different effective refractive indices and two modes are strongly excited which form the basis of an interferometer. We applied the concept to 1.30/1.31 μm and 1.31/1.55 μm wavelength combiners on an InP substrate. The lengths of the devices are 1272 μm and 484 μm with simulated insertion losses of 0.6 dB and 0.67 dB respectively.

Gastroenterology clinics of North America, 2014

Anti-tumor necrosis factor-α (TNF) agents, including infliximab, adalimumab, and certolizumab peg... more Anti-tumor necrosis factor-α (TNF) agents, including infliximab, adalimumab, and certolizumab pegol, are effective medications for the management of moderate to severe Crohn disease (CD). They are effective in inducing and maintaining clinical remission, inducing mucosal healing, improving quality of life, and reducing the risk of hospitalization and surgery in adult and pediatric patients with CD. Future research into comparative effectiveness of different agents, as well as better understanding of predictors of response, is warranted to allow optimization of therapeutic response.

Nature reviews. Gastroenterology & hepatology, 2015

IBD is an established risk factor for venous thromboembolism. In the past few years, studies have... more IBD is an established risk factor for venous thromboembolism. In the past few years, studies have suggested that patients with IBD might also be at an increased risk of coronary heart disease and stroke. The increased risk is thought to be similar to the level of risk seen in patients with other chronic systemic inflammatory diseases such as rheumatoid arthritis. The risk of developing these conditions is particularly increased in young adults with IBD, and more so in women than in men. Conventional cardiovascular risk factors are not over-represented in patients with IBD, so the increased risk could be attributable to inflammation-mediated atherosclerosis. Patients with IBD often have premature atherosclerosis and have biochemical and genetic markers similar to those seen in patients with atherosclerotic cardiovascular disease. The role of chronic inflammation in IBD-associated cardiovascular disease merits further evaluation. Particular attention should be given to the increased r...

Gastrointestinal Endoscopy, 2014

Annals of internal medicine, Jan 6, 2015

The relative efficacy of available treatments of knee osteoarthritis (OA) must be determined for ... more The relative efficacy of available treatments of knee osteoarthritis (OA) must be determined for rational treatment algorithms to be formulated. To examine the efficacy of treatments of primary knee OA using a network meta-analysis design, which estimates relative effects of all treatments against each other. MEDLINE, EMBASE, Web of Science, Google Scholar, Cochrane Central Register of Controlled Trials from inception through 15 August 2014, and unpublished data. Randomized trials of adults with knee OA comparing 2 or more of the following: acetaminophen, diclofenac, ibuprofen, naproxen, celecoxib, intra-articular (IA) corticosteroids, IA hyaluronic acid, oral placebo, and IA placebo. Two reviewers independently abstracted study data and assessed study quality. Standardized mean differences were calculated for pain, function, and stiffness at 3-month follow-up. Network meta-analysis was performed using a Bayesian random-effects model; 137 studies comprising 33 243 participants were ...

Scandinavian Journal of Infectious Diseases, 2011

We present the case of an international traveller who was eventually diagnosed with amoebiasis an... more We present the case of an international traveller who was eventually diagnosed with amoebiasis and autosomal dominant polycystic kidney disease (ADPKD) after she presented with recurring fevers. The patient was also diagnosed with non-amoebic bacterial hepatitis. Positron emission tomography (PET) can play an important role in locating the source of infection in patients with ADPKD when hepatic or renal infection is suspected. It can also be used to document clinical resolution of infection in difficult cases. Hepatic parenchymal infections in ADPKD patients may warrant a prolonged course of rotating antibiotics.

Journal of Periodontology, 1996

It is our central hypothesis that periodontal diseases, which are chronic Gram-negative infection... more It is our central hypothesis that periodontal diseases, which are chronic Gram-negative infections, represent a previously unrecognized risk factor for atherosclerosis and thromboembolic events. Previous studies have demonstrated an association between periodontal disease severity and risk of coronary heart disease and stroke. We hypothesize that this association may be due to an underlying inflammatory response trait, which places an individual at high risk for developing both periodontal disease and atherosclerosis. We further suggest that periodontal disease, once established, provides a biological burden of endotoxin (lipopolysaccharide) and inflammatory cytokines (especially TxA2, IL-1 beta, PGE2, and TNF-alpha) which serve to initiate and exacerbate atherogenesis and thromboembolic events. A cohort study was conducted using combined data from the Normative Aging Study and the Dental Longitudinal Study sponsored by the United States Department of Veterans Affairs. Mean bone loss scores and worst probing pocket depth scores per tooth were measured on 1,147 men during 1968 to 1971. Information gathered during follow-up examinations showed that 207 men developed coronary heart disease (CHD), 59 died of CHD, and 40 had strokes. Incidence odds ratios adjusted for established cardiovascular risk factors were 1.5, 1.9, and 2.8 for bone loss and total CHD, fatal CHD, and stroke, respectively. Levels of bone loss and cumulative incidence of total CHD and fatal CHD indicated a biologic gradient between severity of exposure and occurrence of disease.

Journal of Clinical Microbiology, 2012

The contribution of environmental surface contamination with pathogenic organisms to the developm... more The contribution of environmental surface contamination with pathogenic organisms to the development of health care-associated infections (HAI) has not been well defined. The microbial burden (MB) associated with commonly touched surfaces in intensive care units (ICUs) was determined by sampling six objects in 16 rooms in ICUs in three hospitals over 43 months. At month 23, copper-alloy surfaces, with inherent antimicrobial properties, were installed onto six monitored objects in 8 of 16 rooms, and the effect that this application had on the intrinsic MB present on the six objects was assessed. Census continued in rooms with and without copper for an additional 21 months. In concert with routine infection control practices, the average MB found for the six objects assessed in the clinical environment during the preintervention phase was 28 times higher (6,985 CFU/100 cm 2 ; n = 3,977 objects sampled) than levels proposed as benign immediately after terminal cleaning (<250 CFU/100...

Journal of Clinical Gastroenterology, 2010

Constipation is one of the most common digestive problems in North America with significant psych... more Constipation is one of the most common digestive problems in North America with significant psychosocioeconomic implications. It is caused by either a primary disorder of colonic and anorectal function or by many secondary conditions such as constipating drugs, metabolic disorders and other colorectal problems. Given the heterogeneity of problems that cause constipation, defining the underlying pathophysiology is increasingly being recognized as a key step toward optimal management. Colonic manometry with sensation and tone assessment (barostat) and anorectal manometry with rectal sensation and compliance assessment and balloon expulsion test can provide a comprehensive evaluation of colonic and anorectal sensorimotor function and facilitate a diagnosis of slow transit constipation, dyssynergic defecation or irritable bowel syndrome, or an overlap of these disorders. This review provides a critical appraisal of the role of manometric techniques toward augmenting our understanding of colonic and anorectal physiology, both in health and constipation and discussing their clinical utility in the diagnosis and management of chronic constipation.

International Journal of Cardiology, 2013

Gastroenterology Clinics of North America, 2010

Chronic constipation (CC) affects 20% of the population, 1 has a significant effect on quality of... more Chronic constipation (CC) affects 20% of the population, 1 has a significant effect on quality of life and use of health care resources including drug therapy, 2 and causes significant psychological distress. 3 Almost 85% of physician visits for constipation result in a prescription for laxatives, 2 and $821 million is spent annually on over-thecounter laxatives. 3 Constipation comprises many symptoms such as hard stools, excessive straining, infrequent bowel movement, feeling of incomplete evacuation, and abdominal bloating; its treatment largely encompasses relieving these symptoms and restoring a normal bowel habit. An essential component of management of CC is identification and management of secondary causes such as drug-induced constipation, for example opioid-induced constipation or an obstructive lesion in the colon, the management of which usually results in resolution of constipation. If excluded, primary constipation consists of 3 overlapping subtypes 3,4 : (1) slow transit constipation, characterized by prolonged transit through the colon owing to a primary dysfunction of colonic smooth muscle (myopathy) or its nerve innervations (neuropathy)-this usually requires aggressive medical management but may need surgical intervention 3 ; (2) dyssynergic defecation, a disorder of impaired abdominal, rectoanal, and pelvic floor muscle coordination that requires both medical management and biofeedback treatment 3 ; (3) constipation-predominant irritable bowel syndrome (IBS-C), seen in patients in whom abdominal pain or discomfort is the predominant symptom with usually normal colonic transit and pelvic floor function, and thought to be a result of an interaction of genetic, environmental, social, biologic, Conflict of interest: None.