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Dive into the research topics where Hartley Cohen is active.

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Featured researches published by Hartley Cohen.


The New England Journal of Medicine | 1989

Prevalence of Helicobacter pylori Infection and Histologic Gastritis in Asymptomatic Persons

Cornelius P. Dooley; Hartley Cohen; Patrick L. Fitzgibbons; Madeline Bauer; Maria D. Appleman; Guillermo I. Perez-Perez; Martin J. Blaser

We estimated the prevalences of Helicobacter pylori (formerly called Campylobacter pylori) infection and histologic gastritis in 113 asymptomatic persons, using endoscopic biopsy of the gastric antrum and corpus. Unsuspected lesions, mainly mucosal erosions, were revealed at endoscopy in 16 subjects (14 percent). Gastritis was found in 42 subjects (37 percent), of whom 36 (32 percent of the total) were found to be infected with H. pylori on the basis of hematoxylin-eosin staining. H. pylori was not found in any of the 71 subjects with normal histologic features. Gastritis and H. pylori were noted in both the antrum and corpus in 75 percent of those infected (n = 27). The prevalence of H. pylori infection increased from 10 percent (2 of 20 subjects) in those between the ages of 18 and 29, to 47 percent (7 of 15) in those between the ages of 60 and 69, but the effect of age did not reach statistical significance. The prevalence of gastritis increased significantly with advancing age. Stepwise logistic regression analysis revealed that the relative risk for H. pylori infection associated with recent (within six months) antibiotic use was 5.8 (95 percent confidence interval, 1.5 to 22.1), whereas the relative risk was 6.5 (95 percent confidence interval, 1.4 to 29.2) for those who had never used bismuth compounds. We conclude that histologic gastritis and H. pylori infection commonly occur in the stomach of apparently normal persons and increase in prevalence with advancing age. All the subjects with H. pylori infection had gastritis, suggesting a possible etiologic role for the bacterium in the histologic lesion.


Journal of Clinical Oncology | 1998

ERCC1 mRNA levels complement thymidylate synthase mRNA levels in predicting response and survival for gastric cancer patients receiving combination cisplatin and fluorouracil chemotherapy.

Ralf Metzger; Cynthia G. Leichman; Kathleen D. Danenberg; Peter V. Danenberg; Heinz-Josef Lenz; Kazuhiko Hayashi; Susan Groshen; Dennis Salonga; Hartley Cohen; Loren Laine; Peter F. Crookes; Howard Silberman; Joaquina Baranda; Brahma Konda; Lawrence Leichman

PURPOSE We have previously shown that relative thymidylate synthase (TS) mRNA levels in primary gastric adenocarcinomas treated with fluorouracil (5-FU) and cisplatin are inversely associated with response and survival. This is a presumed function of TS as a target for 5-FU activity. We now test the hypotheses that the relative mRNA level of the excision repair cross-complementing (ERCC1) gene is inversely associated with response and survival as an independent function of cisplatin efficacy. PATIENTS AND METHODS Patients had intact, untreated, primary gastric adenocarcinoma cancer and were evaluated for eligibility on a preoperative cisplatin infusion-5-FU protocol. cDNA, derived from primary gastric tumors before chemotherapy, was used to determine ERCC1 mRNA levels, expressed as the ratio of polymerase chain reaction (PCR) product of the ERCC1 gene and the beta-actin gene. RESULTS The median ERCC1 mRNA level from 38 primary gastric cancers (33 assessable for response) was 5.8 x 10(-3) (range, 1.8 x 10(-3) to 19.5 x 10(-3)). Of 17 responding patients, 13 (76%) were less than or equal to 5.8 x 10(-3) and four were greater than 5.8 x 10(-3) (P = .003). The median survival for patients with ERCC1 mRNA levels less than or equal to 5.8 x 10(-3) has not been reached, whereas for those greater than 5.8 x 10(-3) it was 5.4 months (P = .034). The median TS mRNA level, 3.7 x 10(-3) (range, 0.9 to 18.9) also segregated responsive versus resistant tumors (P = .024). With both ERCC1 and TS mRNA levels below their medians, 11 of 13 patients (85%) responded; with both ERCC1 and TS mRNA levels above their medians, two of 10 patients (20%) responded (P = .003). CONCLUSION Considered separately, either ERCC1 or TS mRNA levels in a primary gastric adenocarcinoma has a statistically significant relationship to response. ERCC1 mRNA levels have a statistically significant association with survival; in this cohort TS mRNA levels did not reach statistically significant association with survival as in our previous publication. Whether these molecular parameters are independent of each other as predictors of outcome remains to be determined.


Journal of Clinical Oncology | 1996

Thymidylate synthase mRNA level in adenocarcinoma of the stomach: a predictor for primary tumor response and overall survival.

Heinz-Josef Lenz; Cynthia G. Leichman; Kathleen D. Danenberg; Peter V. Danenberg; Susan Groshen; Hartley Cohen; Loren Laine; Peter F. Crookes; Howard Silberman; Joaquina Baranda; Yolee Garcia; James Li; Lawrence Leichman

PURPOSE We tested the hypothesis that polymerase chain reaction (PCR) quantitation of the enzyme thymidylate synthase (TS) within a primary adenocarcinoma of the stomach, has an inverse relationship to response and survival for patients who receive fluorouracil (5FU)-based chemotherapy. PATIENTS AND METHODS Before systemic chemotherapy, the genetic expression of TS (TSmRNA level) was determined using a PCR method. Gene expression was calculated by determining the ratio between the amount of radiolabeled PCR product with the linear amplification range of the TS gene and the beta-actin gene. Chemotherapy consisted of two cycles of protracted infusion (PI) 5FU 200 mg/m2/d administered for 3 weeks with leucovorin 20 mg/m2/w. Cisplatin 100 mg/m2 was administered on day 1. RESULTS Sixty-five patients with primary gastric cancer had a median TS mRNA level of 4.6 x 10(-3) (range, 0.9 to 20.1 x 10(-3)). Thirty-five percent of patients had measurable responses in their primary tumors. The mean gastric cancer TSmRNA level in responding and resistant patients is statistically significant (P < .001). The median survival time was 43+ months for treated patients with TSmRNA levels less than the median and 6 months for those with TS m-RNA levels greater than the median (P = .003). CONCLUSION The genetic expression of TS (TSmRNA level) influences response to 5FU-based chemotherapy and survival for a cohort of patients with primary gastric cancer. Confirmation of these data could lead to therapeutic decisions based on specific molecular properties within a tumor.


Annals of Internal Medicine | 1988

The Clinical Significance of Campylobacter pylori

Cornelius P. Dooley; Hartley Cohen

Campylobacter pylori has recently been isolated from gastric mucosal biopsy specimens. Campylobacter pylori has many attributes in common with other campylobacters but it may represent a new genus. It produces abundant quantities of urease, and this property has been used to develop a rapid diagnostic test. The organism is found predominantly beneath the gastric mucus layer that lines the surface epithelium of the stomach. Infection with C. pylori causes an acute histologic gastritis which may become chronic. The bacterium is the etiologic agent in type-B gastritis. Prevalence of the organism in asymptomatic persons appears to be age related. Campylobacter pylori is found commonly in patients with peptic ulcer disease, always in association with chronic gastritis. Eradication of the organism is associated with healing of the gastritis and a lower relapse rate in duodenal ulcer disease. A role for the organism in other upper gastrointestinal diseases is unproven.


Gastrointestinal Endoscopy | 1996

Prospective comparison of commercially available rapid urease tests for the diagnosis of Helicobacter pylori

Loren Laine; David N. Lewin; Wesley Y. Naritoku; Roque Estrada; Hartley Cohen

BACKGROUND Rapid urease testing is the initial endoscopic test of choice for the diagnosis of Helicobacter pylori. Determination of the relative diagnostic yields and times to a positive test for the different rapid urease tests is important for endoscopists. We compared three commercially available tests using histologic examination and culture as a gold standard. METHODS Patients undergoing upper endoscopy had six biopsy specimens taken from the antrum and six from the body with a large-channel biopsy forceps. Each set of six specimens was divided as follows: one each for CLOtest, Hpfast, and Pyloritek rapid urease tests; one for culture; and two for histologic examination (H&E, Genta). All tests were read every 15 minutes for 1 hour; the final reading for Pyloritek was at 1 hour. CLOtest and Hpfast were also read at 4 hours and 24 hours. RESULTS One hundred seventy-three sets of biopsy specimens from 87 patients were evaluated; 98 (57%) of the 173 sets were positive for H. pylori by histologic examination and/or culture. The mean and median times to a positive test were significantly less for Pyloritek (0.5 +/- 0.02 hour and 0.5 hour) than for CLOtest (2.0 +/- 0.6 hour and 0.75 hour) or Hpfast (2.2 +/- 0.6 hour and 0.5 hour). The sensitivities at the final readings were similar among the three tests (CLOtest: 93%; Hpfast: 88%; Pyloritek: 89%), but sensitivities at 1 hour were significantly better for Pyloritek (89%) than for CLOtest (71%) or Hpfast (66%). At 4 hours, sensitivities for CLOtest and Hpfast improved significantly and were not significantly different from those of Pyloritek. Specificities were 99% to 100% at all times for all three tests. CONCLUSION The three rapid urease tests, CLOtest, Hpfast, and Pyloritek, provide comparable results, with sensitivities around 90% and specificities around 100%. The Pyloritek becomes positive more rapidly than the CLOtest or Hpfast. If a reading is desired within 1 hour, the Pyloritek provides a greater sensitivity than the CLOtest or Hpfast without any sacrifice in specificity.


Gastroenterology | 1991

Helicobacter pylori infection in pernicious anemia: A prospective controlled study

Tse-Ling Fong; Cornelius P. Dooley; Margarita Dehesa; Hartley Cohen; Ralph Carmel; Patrick L. Fitzgibbons; Guillermo I. Perez-Perez; Martin J. Blaser

Although some authors believe that Helicobacter pylori is the etiologic agent in chronic nonspecific gastritis, it has also been suggested that the bacterium colonizes inflamed mucosa as a secondary event. This study documents the prevalence of H. pylori in 28 patients with pernicious anemia and compares the findings with those of a group of 28 age-, race-, and sex-matched asymptomatic control subjects. All subjects underwent endoscopy with biopsy of the gastric antrum and corpus. A sample of serum was obtained before endoscopy for determination of antibodies (immunoglobulin A and immunoglobulin G) to H. pylori. The prevalence of H. pylori (by biopsy) in patients with pernicious anemia was significantly less than that in controls (11% vs. 71%, P less than 0.0001). All patients with pernicious anemia had abnormalities of corpus histology (inflammation and/or atrophy). In addition, 50% of patients with pernicious anemia had a lymphocytic infiltration of the antrum. All controls with H. pylori had gastritis, 50% having active chronic gastritis. Atrophic changes of the corpus were more commonly found in patients with pernicious anemia (75% vs. 7%, P less than 0.0001). Serology and biopsy results correlated poorly in the patients with pernicious anemia: all 5 patients with positive serology results had negative biopsy results, whereas all 3 patients with positive cultures on biopsy had negative serological studies. In conclusion, patients with pernicious anemia are protected from infection with H. pylori, and H. pylori does not passively colonize mucosa inflamed by an unrelated process.


Gastroenterology | 1992

Prospective evaluation of immediate versus delayed refeeding and prognostic value of endoscopy in patients with upper gastrointestinal hemorrhage

Loren Laine; Hartley Cohen; John Brodhead; David S. Cantor; Francisco J Nachón García; Mary Mosquera

The effects of immediate vs. delayed refeeding and the prognostic value of endoscopic findings in patients with major upper gastrointestinal hemorrhage were assessed in a prospective randomized study. Entry criteria were clinical evidence of major hemorrhage and endoscopic evidence of a Mallory-Weiss tear or an ulcer with a clean base, flat spot, or clot. Two hundred fifty-eight patients were randomly assigned to groups receiving a regular diet immediately or nothing by mouth for 36 hours, then clear liquids for 12 hours, and a regular diet thereafter. Outcomes in the immediate and delayed refeeding groups were comparable: rebleeding occurred in 4% vs. 5%; urgent intervention, 2% vs. 2%; and deaths, 1% vs. 1%, respectively. Rebleeding occurred in 2 (2%) of 96 patients with cleanbased ulcers, 5 (8%) of 65 with ulcers with spots, 3 (14%) of 21 with ulcers with clots (P = 0.05, 3 x 2 chi2 test), and 1 (2%) of 66 with Mallory-Weiss tears. It is concluded that the time of refeeding does not influence the hospital course of patients with a low risk of recurrent bleeding. Patients with clean-based ulcers or nonbleeding Mallory-Weiss tears may be refed and discharged home immediately after stabilization.


Annals of Surgical Oncology | 2002

Placement of self-expanding metal stents for acute malignant large-bowel obstruction: A collective review

Christine E. Dauphine; Patrick Y. Tan; W Robert BeartJr.; Petar Vukasin; Hartley Cohen; Marvin L. Corman

BackgroundThe purpose of this study was to review our experience with self-expanding metal stents as the initial interventional approach in the management of acute malignant large-bowel obstruction.MethodsTwenty-six patients who underwent placement of colonic stents at our institution between June 1994 and June 2000 were identified and reviewed.ResultsIn 14 patients, the stents were placed for palliation, whereas in 12, they were placed as a bridge to surgery. In 22 patients (85%), stent placement was successful on the first occasion. In the remaining four individuals, one was successfully stented at the second occasion, and three required emergency surgery. Nine of the 12 patients (75%) in the bridge-to-surgery group underwent elective colon resection. In the palliative group, four patients (29%) had reobstruction of the stents, and in one (9%), the stent migrated. In the remaining nine patients (64%), the stent was patent until the patient died or until the time of last follow-up (median, 156 days).ConclusionsIn our experience with 26 patients who developed a complete bowel obstruction as a consequence of a malignant tumor, placement of colonic stents to achieve immediate nonoperative decompression proved to be both safe and effective. Subsequent elective resection was accomplished in the majority of resectable cases.


The American Journal of Gastroenterology | 2011

Development and validation of a novel patient educational booklet to enhance colonoscopy preparation.

Brennan M. Spiegel; Jennifer Talley; Paul G. Shekelle; Nikhil Agarwal; Bradley J. Snyder; Roger Bolus; Nicole Kurzbard; Michael Chan; Andrew Ho; Marc Kaneshiro; Kristina Cordasco; Hartley Cohen

OBJECTIVES:The success of colonoscopy depends on high-quality bowel preparation by patients; yet inadequate preparation is common. We developed and tested an educational booklet to improve bowel preparation quality.METHODS:We conducted patient cognitive interviews to identify knowledge and belief barriers to colonoscopy preparation. We used these interviews to create an educational booklet to enhance preparatory behaviors. We then prospectively randomized patients scheduled for outpatient colonoscopy at a VA Medical Center to receive usual instructions vs. the booklet before colonoscopy. Patients in both groups received standard pharmacy instructions for single-dose bowel preparation; the protocol did not specify which purgatives to prescribe. The primary outcome was preparation quality based on blinded ratings using the validated Ottawa score. We performed bivariate analyses to compare mean scores between groups using a t-test, and logistic regression to measure the booklet effect on preparation quality, adjusting for potential confounders.RESULTS:A total of 436 patients were randomized between arms. In an intention-to-treat analysis of the primary outcome, mean Ottawa scores were superior in patients allocated to booklet vs. controls (P=0.03). An intention-to-treat analysis of the secondary outcome revealed a “good” preparation in 68 vs. 46% of booklet and control patients, respectively (P=0.054). In a per-protocol analysis limited to patients who actually received the booklet, preparation was good in 76 vs. 46% patients, respectively (P<0.00001). Regression analysis revealed that booklet receipt increased the odds of good preparation by 3.7 times (95% confidence interval=2.3–5.8).CONCLUSIONS:Provision of a novel educational booklet considerably improves preparation quality in patients receiving single-dose purgatives. The effect of the booklet on split-dose purgatives remains untested and will be evaluated in future research.


European Journal of Haematology | 2009

Low serum cobalamin levels occur frequently in the acquired immune deficiency syndrome and related disorders

Ronald L. Burkes; Hartley Cohen; Mark Krailo; Robert M. Sinow; Ralph Carmel

Low serum cobalamin levels in 10 patients with AIDS or AIDS‐related complex led us to also prospectively survey 40 homosexual men in our AIDS clinic. 8 of the latter (20%) had low cobalamin values. We found no evidence of megaloblastic changes in the blood or bone marrow. Assessment disclosed malabsorption of cobalamin in only 1 of 6 cases tested for it. 6 of the patients were treated with cobalamin and had no hematologic response. It appears that low serum cobalamin levels in AIDS and related disorders do not usually represent overt cobalamin deficiency. While malabsorption is occasionally responsible for the low cobalamin level, in most cases the cause is unknown and may reflect a serum abnormality similar to that in multiple myeloma. AIDS and related disorders should be considered in the differential diagnosis of unexplained low cobalamin levels.

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Brennan M. Spiegel

Cedars-Sinai Medical Center

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Loren Laine

University of Southern California

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Joseph R. Pisegna

National Institutes of Health

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Hank S. Wang

University of California

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Minh Nguyen

Cedars-Sinai Medical Center

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Cornelius P. Dooley

University of Southern California

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Rushabh Modi

Cedars-Sinai Medical Center

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David N. Lewin

University of Southern California

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