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Dive into the research topics where Leonard A. Katz is active.

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Featured researches published by Leonard A. Katz.


Alimentary Pharmacology & Therapeutics | 2007

Comparison of gastric emptying of a nondigestible capsule to a radio-labelled meal in healthy and gastroparetic subjects

Braden Kuo; R. W. Mccallum; Kenneth L. Koch; Michael D. Sitrin; John M. Wo; William D. Chey; William L. Hasler; Jeffrey M. Lackner; Leonard A. Katz; John R. Semler; Gregory E. Wilding; Henry P. Parkman

Background  Gastric emptying scintigraphy (GES) using a radio‐labelled meal is used to measure gastric emptying. A nondigestible capsule, SmartPill, records luminal pH, temperature, and pressure during gastrointestinal transit providing a measure of gastric emptying time (GET).


Clinical Gastroenterology and Hepatology | 2008

Self-Administered Cognitive Behavior Therapy for Moderate to Severe Irritable Bowel Syndrome: Clinical Efficacy, Tolerability, Feasibility

Jeffrey M. Lackner; James Jaccard; Susan S. Krasner; Leonard A. Katz; Gregory D. Gudleski; Kenneth A. Holroyd

BACKGROUND & AIMS Given the limitations of conventional therapies and restrictions imposed on newer pharmacologic agents, there is an urgent need to develop efficacious and efficient treatments that teach patients behavioral self-management skills for relieving irritable bowel syndrome (IBS) symptoms and associated problems. METHODS Seventy-five Rome II diagnosed IBS patients (86% female) without comorbid gastrointestinal disease were recruited from local physicians and the community and randomized to either 2 versions of cognitive behavior therapy (CBT) (10-session, therapist-administered CBT vs 4-session, patient-administered CBT) or a wait list control (WLC) that controlled for threats to internal validity. Final assessment occurred 2 weeks after the 10-week treatment phase ended. Outcome measures included adequate relief from pain and bowel symptoms, global improvement of IBS symptoms (CGI-Improvement Scale), IBS symptom severity scale (IBS SSS), quality of life (IBSQOL), psychological distress (Brief Symptom Inventory), and patient satisfaction (Client Satisfaction Scale). RESULTS At week 12, both CBT versions were significantly (P < .05) superior to WLC in the percentage of participants reporting adequate relief (eg, minimal contact CBT, 72%; standard CBT, 60.9%; WLC, 7.4%) and improvement of symptoms. CBT-treated patients reported significantly improved quality of life and IBS symptom severity but not psychological distress relative to WLC patients (P < .0001). CONCLUSIONS Data from this pilot study lend preliminary empirical support to a brief patient-administered CBT regimen capable of providing short-term relief from IBS symptoms largely unresponsive to conventional therapies.


Alimentary Pharmacology & Therapeutics | 2009

The assessment of regional gut transit times in healthy controls and patients with gastroparesis using wireless motility technology

Irene Sarosiek; K. H. Selover; Leonard A. Katz; John R. Semler; Gregory E. Wilding; Jeffrey M. Lackner; Michael D. Sitrin; Braden Kuo; William D. Chey; William L. Hasler; K. L. Koch; Henry P. Parkman; J. Sarosiek; R. W. Mccallum

Background  Wireless pH and pressure motility capsule (wireless motility capsule) technology provides a method to assess regional gastrointestinal transit times.


Neurogastroenterology and Motility | 2010

Motility of the antroduodenum in healthy and gastroparetics characterized by wireless motility capsule.

Lenuta Kloetzer; William D. Chey; R. W. Mccallum; K. L. Koch; John M. Wo; Michael D. Sitrin; Leonard A. Katz; Jeffrey M. Lackner; Henry P. Parkman; Gregory E. Wilding; John R. Semler; William L. Hasler; Braden Kuo

Background  The wireless motility capsule (WMC) measures intraluminal pH and pressure, and records transit time and contractile activity throughout the gastrointestinal tract. Our hypothesis is that WMC can differentiate antroduodenal pressure profiles between healthy people and patients with upper gut motility dysfunctions.


Clinical Gastroenterology and Hepatology | 2013

Type, rather than number, of mental and physical comorbidities increases the severity of symptoms in patients with irritable bowel syndrome.

Jeffrey M. Lackner; Changxing Ma; Laurie Keefer; Darren M. Brenner; Gregory D. Gudleski; Nikhil Satchidanand; Rebecca Firth; Michael D. Sitrin; Leonard A. Katz; Susan S. Krasner; Sarah Ballou; Bruce D. Naliboff; Emeran A. Mayer

BACKGROUND & AIMS Irritable bowel syndrome (IBS) has significant mental and physical comorbidities. However, little is known about the day-to-day burden these comorbidities place on quality of life (QOL), physical and mental function, distress, and symptoms of patients. METHODS We collected cross-sectional data from 175 patients with IBS, which was diagnosed on the basis of Rome III criteria (median age, 41 years; 78% women), who were referred to 2 specialty care clinics. Patients completed psychiatric interviews, a physical comorbidity checklist, the IBS Symptom Severity Scale, the IBS-QOL instrument, the Brief Symptom Inventory, the abdominal pain intensity scale, and the Short Form-12 Health Survey. RESULTS Patients with IBS reported an average of 5 comorbidities (1 mental, 4 physical). Subjects with more comorbidities reported worse QOL after adjusting for confounding variables. Multiple linear regression analyses indicated that comorbidity type was more consistently and strongly associated with illness burden indicators than disease counts. Of 10,296 possible physical-mental comorbidity pairs, 6 of the 10 most frequent dyads involved specific conditions (generalized anxiety, depression, back pain, agoraphobia, tension headache, and insomnia). These combinations were consistently associated with greater illness and symptom burdens (QOL, mental and physical function, distress, more severe symptoms of IBS, and pain). CONCLUSIONS Comorbidities are common among patients with IBS. They are associated with distress and reduced QOL. Specific comorbidities are associated with more severe symptoms of IBS.


Psychosomatic Medicine | 2006

Measuring health-related quality of life in patients with irritable bowel syndrome: can less be more?

Jeffrey M. Lackner; Gregory D. Gudleski; Matthew M. Zack; Leonard A. Katz; Catherine Powell; Susan S. Krasner; Elizabeth Holmes; Kathryn Dorscheimer

Objective: This study assessed the ability of a brief, well-validated generic health-related quality of life (HRQOL) measure to characterize the symptom burden of patients with irritable bowel syndrome (IBS) with reference to a large survey of U.S. community-living adults. Methods: One hundred four Rome II diagnosed patients with IBS completed measures of pain, psychological dysfunction (neuroticism, somatization, distress, abuse), and HRQOL (SF-36, IBS-QOL, CDC HRQOL-4) during baseline assessment of a National Institutes of Health-funded clinical trial. The four-item CDC HRQOL-4 assesses global health and the number of days in the past 30 days resulting from poor physical health, poor mental health, and activity limitation. Results: Patients with IBS averaged 15 of 30 days with poor physical or mental health. These average overall unhealthy days exceeded those of respondents with arthritis, diabetes, heart disease/stroke, cancer, and class III obesity (body mass index ≥40 kg/m2) from the U.S. survey. Fifteen percent of patients identified musculoskeletal disorders, not IBS symptoms, as the major cause of their activity limitation. Overall unhealthy days among patients with IBS varied directly with IBS symptom severity, abuse, pain, and psychological distress. Controlling for personality variables that influence perception and reporting HRQOL did not diminish the statistical significance of associations between the CDC HRQOL-4 and other study measures. Conclusions: The CDC HRQOL-4 is a psychometrically sound, rapid, and efficient instrument whose HRQOL profile reflects the symptom burden of moderate-to-severe IBS, is sensitive to treatment effects associated with cognitive behavior therapy, and is not a proxy for personality variables identified as potential confounders of HRQOL. HRQOL is related to but not redundant with psychological distress. GERD = gastroesophageal reflux disease; HRQOL = health-related quality of life; IBS = irritable bowel syndrome; BRFSS = Behavioral Risk Factor Surveillance System; CDC = Centers for Disease Control and Prevention.


Clinical Gastroenterology and Hepatology | 2010

Rapid Response to Cognitive Behavior Therapy Predicts Treatment Outcome in Patients With Irritable Bowel Syndrome

Jeffrey M. Lackner; Gregory D. Gudleski; Laurie Keefer; Susan S. Krasner; Catherine Powell; Leonard A. Katz

BACKGROUND & AIMS Cognitive behavior therapy (CBT) is an empirically validated treatment for irritable bowel syndrome (IBS), yet it is unclear for whom and under what circumstances it is most effective. We investigated whether patients who achieved a positive response soon after CBT onset (by week 4), termed rapid responders (RRs), maintain treatment gains compared with non-rapid responders. We also characterized the psychosocial profile of RRs on clinically relevant variables (eg, health status, IBS symptom severity, distress). METHODS The study included 71 individuals (age, 18-70 y) whose IBS symptoms were consistent with Rome II criteria and were of at least moderate severity. Patients were assigned randomly to undergo a wait list control; 10 weekly 1-hour sessions of CBT; or four 1-hour CBT sessions over 10 weeks. RRs were classified as patients who reported adequate relief of pain, adequate relief of bowel symptoms, and a decrease in total IBS severity scores of 50 or greater by week 4. RESULTS Of patients undergoing CBT, 30% were RRs; 90% to 95% of the RRs maintained gains at the immediate and 3-month follow-up examinations. Although the RRs reported more severe IBS symptoms at baseline, they achieved more substantial, sustained IBS symptom reduction than non-rapid responders. Both dosages of CBT had comparable rates of RR. CONCLUSIONS A significant proportion of IBS patients treated with CBT have a positive response within 4 weeks of treatment; these patients are more likely to maintain treatment gains than patients without a rapid response. A rapid response is not contingent on the amount of face-to-face contact with a clinician.


Neurogastroenterology and Motility | 2010

The ties that bind: perceived social support, stress, and IBS in severely affected patients

Jeffrey M. Lackner; A. M. Brasel; Brian M. Quigley; Laurie Keefer; Susan S. Krasner; Cathrine Powell; Leonard A. Katz; Michael D. Sitrin

Background  This study assessed the association between social support and the severity of irritable bowel syndrome (IBS) symptoms in a sample of severely affected IBS patients recruited to an NIH‐funded clinical trial. In addition, we examined if the effects of social support on IBS pain are mediated through the effects on stress.


American Journal of Physiology-gastrointestinal and Liver Physiology | 2008

Differences in intragastric pH in diabetic vs. idiopathic gastroparesis: relation to degree of gastric retention

William L. Hasler; Radoslav Coleski; William D. Chey; Kenneth L. Koch; Richard W. McCallum; John M. Wo; Braden Kuo; Michael D. Sitrin; Leonard A. Katz; Judy Hwang; John R. Semler; Henry P. Parkman

Evidence suggests that distinct mechanisms underlie diabetic and idiopathic gastroparesis. Differences in gastric acid in gastroparesis of different etiologies and varying degrees of gastric stasis are uninvestigated. We tested the hypotheses that 1) gastric pH profiles show differential alteration in diabetic vs. idiopathic gastroparesis and 2) abnormal pH profiles relate to the severity of gastric stasis. Sixty-four healthy control subjects and 44 gastroparesis patients (20 diabetic, 24 idiopathic) swallowed wireless transmitting capsules and then consumed (99m)Tc-sulfur colloid-labeled meals for gastric scintigraphy. Gastric pH from the capsule was recorded every 5 s. Basal pH was higher in diabetic (3.64 +/- 0.41) vs. control subjects (1.90 +/- 0.18) and idiopathic subjects (2.41 +/- 0.42; P < 0.05). Meals evoked initial pH increases that were greater in diabetic (4.98 +/- 0.32) than idiopathic patients (3.89 +/- 0.39; P = 0.03) but not control subjects (4.48 +/- 0.14). pH nadirs prior to gastric capsule evacuation were higher in diabetic patients (1.50 +/- 0.23) than control subjects (0.58 +/- 0.11; P = 0.003). Four-hour gastric retention was similar in diabetic (18.3 +/- 0.5%) and idiopathic (19.4 +/- 0.5%) patients but higher than control subjects (2.2 +/- 0.5%; P < 0.001). Compared with control subjects, those with moderate-severe stasis (>20% retention at 4 h) had higher basal (3.91 +/- 0.55) and nadir pH (2.23 +/- 0.42) values (P < 0.05). In subgroup analyses, both diabetic and idiopathic patients with moderate-severe gastroparesis exhibited increased pH parameters vs. those with mild gastroparesis. In conclusion, diabetic patients with gastroparesis exhibit reduced gastric acid, an effect more pronounced in those with severely delayed gastric emptying. Idiopathic gastroparetic subjects exhibit nearly normal acid profiles, although those with severely delayed emptying show reduced acid vs. those with mild delays. Thus both etiology and degree of gastric stasis determine gastric acidity in gastroparesis.


Gastroenterology | 1967

Anal Sphincter Pressure Characteristics

Leonard A. Katz; Herbert J. Kaufmann; Howard M. Spiro

Summary A simple method for recording pressures in the anal sphincter during distention at rest and during voluntary contraction is presented. The resting sphincter resists distention until a resting yield pressure is reached, after which further distention of the sphincter produces no further pressure rise. Maximal sphincter pressure is reached by voluntary contraction only after the recording balloon has been distended to the volume needed to reach the resting yield pressure. The ability of the sphincter to resist distention appears to be the mechanism for maintaining continence at rest; however, contraction of the voluntary component of the anal sphincter can forcibly close the sphincter when distended and thereby maintain continence. Of 48 subjects studied, all 14 with incontinence were found to have normal resting yield pressures, but maximal sphincter pressures varied depending upon the cause of incontinence. Most patients with incontinence had low maximal sphincter pressure, but incontinence was not invariable with low maximal sphincter pressure. It is possible to differentiate patients with incontinence as the result of abnormalities of the voluntary component of the anal sphincter from those patients with incontinence of other cause.

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Laurie Keefer

Icahn School of Medicine at Mount Sinai

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