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Featured researches published by John I. Allen.


The American Journal of Medicine | 1978

The natural history of stroke in sickle cell disease

Darleen R. Powars; Brian Wilson; Charles Imbus; Charles H. Pegelow; John I. Allen

Abstract The occurrence and progression of strokes in patients with sickle cell disease and the resultant structural and functional defects were investigated by an indepth study of 35 patients, 32 of whom are part of a natural history study of 537 patients. The relative frequency for all ages is 6 per cent. Strokes are predominantly seen in patients with sickle cell anemia (33 with sickle cell anemia and two with heterozygous hemoglobin S and C (SC) disease). Twenty-five of the patients were less than 20 years old at the time of the first stroke—9.1 per cent of all patients observed during this age range. The actuarial or predictive risk of an initial stroke during the first two decades is 0.761 episodes per 100 person years whereas after age 20 the risk is 0.524 episodes per 100 person years. Children significantly at risk (p


The American Journal of Gastroenterology | 2014

Guidelines on Genetic Evaluation and Management of Lynch Syndrome: A Consensus Statement by the US Multi-Society Task Force on Colorectal Cancer

Francis M. Giardiello; John I. Allen; Jennifer E. Axilbund; C. Richard Boland; Carol A. Burke; Randall W. Burt; James M. Church; Jason A. Dominitz; David A. Johnson; Tonya Kaltenbach; Theodore R. Levin; David A. Lieberman; Douglas J. Robertson; Sapna Syngal; Douglas K. Rex

The Multi-Society Task Force, in collaboration with invited experts, developed guidelines to assist health care providers with the appropriate provision of genetic testing and management of patients at risk for and affected with Lynch syndrome as follows: Figure 1 provides a colorectal cancer risk assessment tool to screen individuals in the office or endoscopy setting; Figure 2 illustrates a strategy for universal screening for Lynch syndrome by tumor testing of patients diagnosed with colorectal cancer; Figures 3,4,5,6 provide algorithms for genetic evaluation of affected and at-risk family members of pedigrees with Lynch syndrome; Table 10 provides guidelines for screening at-risk and affected persons with Lynch syndrome; and Table 12 lists the guidelines for the management of patients with Lynch syndrome. A detailed explanation of Lynch syndrome and the methodology utilized to derive these guidelines, as well as an explanation of, and supporting literature for, these guidelines are provided.


Journal of Parenteral and Enteral Nutrition | 1995

Protein energy malnutrition in severe alcoholic hepatitis : diagnosis and response to treatment

Charles L. Mendenhall; Thomas E. Moritz; Gary A. Roselle; Timothy R. Morgan; Bernard A. Nemchausky; Carlo H. Tamburro; Eugene R. Schiff; Craig J. McClain; Luis Marsano; John I. Allen; Arun Samanta; Robert E. Weesner; William G. Henderson; Thomas S. Chen; Samuel W. French; Antonio Chedid

Background: Active nutrition therapy and the anabolic steroid oxandrolone (OX), in selected patients with severe alcoholic hepatitis, significantly improved liver status and survival. We report here on the changes in their nutritional parameters. Methods: Protein energy malnutrition (PEM) was evaluated and expressed as percent of low normal in 271 patients initially, at 1 month and at 3 months. Active therapy consisted of OX plus a high caloric food supplement vs a matching placebo and a low calorie supplement. Results: PEM was present in every patient; mean PEM score 60% of low normal. Most of the parameters improved significantly from baseline on standard care; the largest improvement seen in visceral proteins, the smallest in fat stores (skinfold thickness). Total PEM score significantly correlated with 6 month mortality (p=.0012). Using logistic regression analysis, creatinine height index, hand grip strength and total peripheral blood lymphocytes were the best risk factors for survival. When CD lymph...


The American Journal of Medicine | 1986

Role of Zinc Supplementation in Type II Diabetes Mellitus

Catherine B. Niewoehner; John I. Allen; Maria G. Boosalis; Allen S. Levine; John E. Morley

Zinc is required for normal immune function and taste acuity and enhances the in vitro effectiveness of insulin. Impaired immune function and taste have been reported in diabetic subjects, and decreased serum zinc levels and hyperzincuria occur in some diabetic subjects and animals. Subjects with type II diabetes were examined to determine whether the similar effects of zinc depletion and diabetes are causally related. Low serum zinc levels were found in 16 of 180 subjects (9 percent). There was no correlation between serum zinc and glycosylated hemoglobin levels. Natural killer cell activity did not differ between diabetic subjects (n = 28) and control subjects (n = 38) and did not correlate with serum zinc levels. T lymphocyte response to phytohemagglutinin was lower in diabetic subjects than in control subjects (70 +/- 10 versus 103 +/- 7 X 10(3) counts per minute) but was not lowest in those with the lowest zinc levels. Taste thresholds for hydrochloric acid, sucrose, sodium chloride, and urea were elevated in diabetic subjects (n = 28) versus control subjects (n = 10), but thresholds did not correlate with glycosylated hemoglobin or serum zinc levels. Zinc supplementation in nine diabetic subjects had no effect on the glycosylated hemoglobin level, natural killer cell activity, or taste thresholds, but it did increase mitogen activity in those with the lowest initial phytohemagglutinin responses. It is concluded that zinc deficiency occurs in a subset of subjects with type II diabetes but is not related to diabetes control and does not explain decreased taste acuity. Zinc deficiency may play a role in abnormal immune function in type II diabetes mellitus.


Annals of Internal Medicine | 1981

Severe Zinc Deficiency in Humans: Association with a Reversible T-Lymphocyte Dysfunction

John I. Allen; Neil E. Kay; Craig J. McClain

Two patients developed severe zinc deficiency with acrodermatitis during parenteral hyperalimentation. The response of circulating T-lymphocytes to phytohemagglutinin was assessed both during the episode of clinical zinc deficiency and after intravenous zinc supplementation as the sole means of nutritional intervention. Maximum T-cell response to phytohemagglutinin, expressed as percent of simultaneous normal control response, was 2.1% and 27.9% in Patients 1 and 2 respectively. After 20 days of intravenous zinc supplementation (12 mg/d), repeat studies showed the T-cell response of Patient 1 to be 221% of the control, and that of Patient 2 to be 139% of control. In addition, Patient 1 was anergic during the period of zinc deficiency and normally reactive after zinc supplementation. These findings agree with extensive animal studies showing the detrimental effect of zinc deficiency on cellular immunity.


Clinical Gastroenterology and Hepatology | 2009

Variation in Detection of Adenomas and Polyps by Colonoscopy and Change Over Time With a Performance Improvement Program

Aasma Shaukat; Cristina Oancea; John H. Bond; Timothy R. Church; John I. Allen

BACKGROUND & AIMS There has been no prospective, community-based study to track changes in adenoma detection by individual physicians over time and to determine the effectiveness of targeted educational interventions. METHODS We prospectively collected information on 47,253 screening colonoscopies in average-risk individuals 50 years and older performed by a community-based practice in the Twin Cities of Minnesota. During a period of 3 years, 5 specific interventions were implemented; each was designed to improve adenoma detection rates. Controlling for patient-related and procedure-related factors, rates of adenoma detection and 3-year trends for individual physicians were plotted, and intraclass correlation coefficients were calculated. Generalized estimating equations were used to identify factors associated with detection of adenomas and polyps. RESULTS At least 1 polyp and 1 adenoma were found in 36% and 22% of examinations, respectively. Adenoma detection rates by endoscopists ranged from 10%-39%. There was no significant improvement during the study period despite planned, systematic interventions. Factors associated with adenoma detection included age of the patient (odds ratio [OR], 1.02; 95% confidence interval [CI], 1.02-1.02), male sex (OR, 1.53; 95% CI, 1.34-1.74), and adequate preparation quality (OR, 2.26; 95% CI, 1.64-3.12). CONCLUSIONS The detection of adenomas by individual physicians during a 3-year period varied and did not appear to change between individual endoscopists, despite planned, systematic interventions. This indicates that other targeted interventions might be required to improve adenoma detection rates among experienced, community gastroenterologists.


Gastroenterology | 1993

Cell-mediated hepatic injury in alcoholic liver disease

Antonio Chedid; Charles L. Mendenhall; Thomas E. Moritz; Samuel W. French; Thomas S. Chen; Timothy R. Morgan; Gary A. Roselle; Bernard A. Nemchausky; Carlo H. Tamburro; Eugene R. Schiff; Craig J. McClain; Luis Marsano; John I. Allen; Arun Samanta; Robert E. Weesner; William G. Henderson

BACKGROUND The mechanism responsible for the initiation and perpetuation of alcoholic liver disease (ALD) remains poorly understood. This investigation attempted to elucidate the role of cell-mediated immune phenomena in the pathogenesis of ethanol-induced liver injury. METHODS Frozen liver biopsy specimens from 144 patients with moderate to severe ALD were examined by the avidin-biotin immunoperoxidase technique for the expression of antigenic markers of T and B lymphocytes, natural killer cells, and class I and II MHC molecules in the tissue. RESULTS Expression of CD3 by lymphocytes correlated significantly with regenerating nodules, intralobular inflammation, central sclerosis, and abnormalities of Kupffer cells. B cells were rarely present, and natural killer cells were absent. CD3+ lymphocytes expressed either CD4 or CD8 surface molecules. Enhanced class I MHC expression correlated significantly with portal inflammation, limiting plate erosion, vascular abnormalities, and hemosiderosis. Expression of class II MHC molecules correlated significantly with necrosis, bile stasis, and Mallory bodies. CONCLUSIONS The distribution and persistence of CD4+ and CD8+ cells in actively advancing ALD, the enhanced MHC expression on hepatocytes, and their relationship to alcoholic hyalin and necrosis lend support to the hypothesis that a cytotoxic T lymphocyte-hepatocyte interaction plays a role, perhaps via lymphokine production, in the genesis or perpetuation of ALD.


Inflammatory Bowel Diseases | 2013

Quality indicators for inflammatory bowel disease: development of process and outcome measures.

Gil Y. Melmed; Corey A. Siegel; Brennan M. Spiegel; John I. Allen; Robert R. Cima; Jean-Frederic Colombel; Themistocles Dassopoulos; Lee A. Denson; Sharon Dudley-Brown; Andrew Garb; Stephen B. Hanauer; Michael D. Kappelman; James D. Lewis; Isabelle Lynch; Amy Moynihan; David T. Rubin; R. Balfour Sartor; Ronald M. Schwartz; Douglas C. Wolf; Thomas A. Ullman

Introduction:Variation in adherence to management guidelines for inflammatory bowel disease (IBD) suggests variable quality of care. Quality indicators (QIs) can be developed to measure the structure, processes, and outcomes of health care delivery. The RAND/UCLA appropriateness method was used to develop a set of process and outcome QIs to define quality of care for IBD. Methods:Guidelines and position papers for IBD published from 2006 to 2011 were reviewed for potential QIs, which were rated by a multidisciplinary panel. Potential process and outcome QIs were discussed at 3 moderated in-person meetings, with pre-meeting and post-meeting confidential electronic voting. Panelists rated the validity and feasibility of QIs on a 1 through 9 scale; disagreement was assessed using a validated index. QIs rated above 8 were selected for the final set. Results:More than 500 potential process QIs were extracted from guidelines. Following ratings and discussion by the first panel, 35 process QIs were selected for literature review. After the second panel, 10 process QIs were included in the final set. Candidate outcome QIs were then derived from physician, nurse, and patient input and ratings, in addition to outcomes associated with candidate process QIs. None of the top QIs exhibited disagreement. Conclusions:A set of QIs for IBD was developed with expert interpretation of the literature and multidisciplinary input. Outcome QIs focused largely on remission and quality of life, whereas process QIs were aimed at therapeutic optimization and patient safety. Evaluation of these QIs in clinical practice is needed to assess the correlation of performance on process QIs with performance on outcome QIs.


The American Journal of Gastroenterology | 2009

Development and Validation of a Colon Cancer Risk Assessment Tool for Patients Undergoing Colonoscopy

Fay Kastrinos; John I. Allen; David H. Stockwell; Elena M. Stoffel; Earl Francis Cook; Muthoka L. Mutinga; Judith Balmaña; Sapna Syngal

OBJECTIVES:Diagnostic criteria for hereditary colorectal cancer (CRC) are complex. “Open-access” colonoscopy makes it challenging to identify who needs genetic evaluation, intensive surveillance, and screening for extracolonic tumors. Our aim was to develop a simple, preprocedural risk assessment tool to identify who may be at highest risk for CRC.METHODS:A total of 631 outpatients undergoing colonoscopy at two academic practices completed a questionnaire assessing personal and family histories of CRC, polyps, and Lynch syndrome (LS)-associated malignancies. Subjects were considered to be high-risk if one of the nine prespecified characteristics of hereditary CRC syndromes was met. Through recursive partitioning analysis, an algorithm of fewest questions needed to capture the most high-risk individuals was developed. The results were validated in 5,335 individuals undergoing colonoscopy at five private endoscopy centers and tested in 285 carriers of mismatch repair mutations associated with LS.RESULTS:About 17.7% and 20.0% of individuals were classified as high-risk in the development and validation cohorts, respectively. Recursive partitioning revealed three questions that were most informative for identifying high-risk patients: (i) “Do you have a first-degree relative with CRC or LS-related cancer diagnosed before age 50?” (ii) “Have you had CRC or polyps diagnosed before age 50?” (iii) “Do you have ≥3 relatives with CRC?” When asked successively, these questions identified 77% of high-risk individuals in both cohorts and 271 of 285 (95%) of mutation carriers.CONCLUSIONS:Approximately one in five individuals undergoing colonoscopy would benefit from further risk assessment. We developed a simple, three-question CRC Risk Assessment Tool to identify the majority of patients who require additional assessment and possible genetic evaluation.


The American Journal of Medicine | 1985

Association between urinary zinc excretion and lymphocyte dysfunction in patients with lung cancer

John I. Allen; Elaine Bell; Maria G. Boosalis; Martin M. Oken; Craig J. McClain; Allen S. Levine; John E. Morley

Patients with bronchogenic carcinoma often have low serum zinc concentrations and sometimes have markedly elevated renal zinc losses. Since normal zinc metabolism is critical for the proper function of T lymphocytes and natural killer cells, the effect of zinc status on T cell phytohemagglutinin response and peripheral blood lymphocyte natural killer cell activity was studied in patients with lung cancer. Mean (+/- SEM) serum zinc concentration in 75 patients with cancer was 67.4 +/- 2.2 micrograms/dl versus 96.0 +/- 8.0 micrograms/dl for normal subjects. Patients with low serum zinc levels (less than 70 micrograms/dl) had significantly higher urine zinc excretion than patients with normal serum zinc levels (1,385 +/- 240 micrograms per 24 hours versus 392 +/- 107 micrograms per 24 hours) (p less than 0.001). This pattern of zinc concentrations (i.e., low serum zinc in combination with high urine zinc) is typical of patients with mild zinc deficiency, and suggests that a mild chronic zinc deficiency state was present in some of these patients. When lymphocyte data were analyzed according to serum zinc concentrations and urinary zinc excretion, low serum zinc concentration and high urine zinc excretion both correlated with depressed T cell phytohemagglutinin response (p less than 0.005 and p less than 0.001, respectively). For instance, mean maximal phytohemagglutinin response in patients with urinary zinc excretion of more than 700 micrograms per 24 hours was 22,132 +/- 3,201 cpm (n = 14) compared with 68,130 +/- 6,850 cpm for patients with normal zinc excretion (n = 7). Peripheral blood lymphocyte natural killer cell activity did not correlate with either serum or urine zinc values. Oral zinc sulfate (220 mg, three times daily for six weeks) was then administered to patients with hyperzincuria (mean = 992 micrograms per 24 hours). Zinc-supplemented patients had normalization of T cell phytohemagglutinin response after zinc therapy, whereas control patients demonstrated continued T cell dysfunction. Natural killer cell activity did not change in either group during the study period. These data suggest that a mild subclinical zinc deficiency state may exist in some patients with lung cancer and may be an important cause of abnormal T cell function. Furthermore, zinc supplementation may be useful to improve lymphocyte function in selected patients. Whether zinc supplementation would alter the course of the disease or the patients prognosis is presently unknown.

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Ann G. Zauber

Memorial Sloan Kettering Cancer Center

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Sidney J. Winawer

Memorial Sloan Kettering Cancer Center

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Andrew D. Feld

Group Health Cooperative

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John H. Bond

University of Minnesota

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