Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Chul Ahn is active.

Publication


Featured researches published by Chul Ahn.


American Journal of Cardiology | 1994

Prevalence of coexistence of coronary artery disease, peripheral arterial disease, and atherothrombotic brain infarction in men and women ≥62 years of age

Wilbert S. Aronow; Chul Ahn

Abstract Our data showed that CAD, PAD, and ABI were more prevalent in men than in women aged ≥62 years. Of our 1,886 patients, only 705 (37%) had no CAD, PAD, or ABI. CAD was present in 43%, PAD in 25%, and ABI in 26% of our population. If ABI was present, CAD was also present in 53% and PAD in 33% of our population. If PAD was present, CAD was also present in 58% and ABI in 34% of our population. If CAD was present, ABI was also present in 32% and PAD in 33% of our population.


American Journal of Medical Genetics | 1996

Polygenic inheritance of Tourette syndrome, stuttering, attention deficit hyperactivity, conduct, and oppositional defiant disorder: The additive and subtractive effect of the three dopaminergic genes—DRD2, DβH, and DAT1

David E. Comings; Shijuan Wu; Connie Chiu; Robert H. Ring; Radhika Gade; Chul Ahn; James P. MacMurray; George Dietz; Donn Muhleman

Polymorphisms of three different dopaminergic genes, dopamine D2 receptor (DRD2), dopamine beta-hydroxylase (D beta H), and dopamine transporter (DAT1), were examined in Tourette syndrome (TS) probands, their relatives, and controls. Each gene individually showed a significant correlation with various behavioral variables in these subjects. The additive and substractive effects of the three genes were examined by genotyping all three genes in the same set of subjects. For 9 of 20 TS associated comorbid behaviors there was a significant linear association between the degree of loading for markers of three genes and the mean behavior scores. The behavior variables showing the significant associations were, in order attention deficit hyperactivity disorder (ADHD), stuttering oppositional defiant, tics, conduct, obsessive-compulsive, mania, alcohol abuse and general anxiety-behaviors that constitute the most overt clinical aspects of TS. For 16 of the 20 behavior scores there was a linear progressive decrease in the mean score with progressively lesser loading for the three gene markers. These results suggest that TS, ADHD, stuttering oppositional defiant and conduct disorder, and other behaviors associated with TS, are polygenic, due in part to these three dopaminergic genes, and that the genetics of other polygenic psychiatric disorders may be deciphered using this technique.


Drug and Alcohol Dependence | 1994

The dopamine D2 receptor gene: a genetic risk factor in substance abuse

David E. Comings; Donn Muhleman; Chul Ahn; Reinhard Gysin; Steven D. Flanagan

Drug abuse has grown to epidemic proportions. Dopaminergic reward pathways have frequently been implicated in the etiology of drug addiction. To examine the possible role of genetic variants of the dopamine D2 (DRD2) gene in susceptibility to drug abuse we determined the prevalence of the TaqI A1 variant of the DRD2 gene in 200 white patients hospitalized in the Addiction Treatment Unit of a Veterans Administration Hospital. While the prevalence of the D2A1 allele was not significantly increased over controls, it did increase from 21% in subjects with alcohol abuse only to 32% in subjects with alcohol dependence only, consistent with other studies showing an association with the severity of alcoholism. By contrast, of 104 subjects with a discharge diagnosis of drug and alcohol abuse/dependence, 42.3% carried the D2A1 allele versus 29.0% of the 763 white controls (representing all white controls published to date) (P = 0.006). Of those who spent more than


Cancer | 1994

Pain management for elderly patients with cancer at home

Betty Ferrell; Bruce A. Ferrell; Chul Ahn; Kim Tran

25/week on two or more substances, 56.9% carried the D2A1 allele versus 28.2% of those abusing a single substance (P < 0.0005). Multiple logistic regression analysis showed a highly significant association between multiple substance abuse based on money spent and the presence of the D2A1 allele (P = 0.0003) and age of onset of abuse (P < 0.0001). D2A1 carriers exceeded D2A2A2 subjects for a history of being expelled from school for fighting (P = 0.001), and of those ever jailed for violent crimes, 53.1% carried the D2A1 allele versus 28.8% of those jailed for non-violent crimes (P = 0.011).(ABSTRACT TRUNCATED AT 250 WORDS)


Journal of the American Geriatrics Society | 1994

Postprandial hypotension in 499 elderly persons in a long-term health care facility

Wilbert S. Aronow; Chul Ahn

Background. Pain is an important problem for patients with cancer and is particularly important for elderly patients with cancer and their family care givers. Increasingly, cancer is managed on an outpatient basis with pain management responsibility assumed by the family at home. This study evaluated a structured pain education program that included three components: basic pain management principles and assessment, pharmaco‐logic interventions, and nondrug treatments.


Cancer | 1996

Endothelial area as a prognostic indicator for invasive breast carcinoma.

Jean F. Simpson; Chul Ahn; Hector Battifora; Jose M. Esteban

OBJECTIVE: To present baseline data from a prospective study of postprandial hypotension in 499 elderly persons in a long‐term health care facility.


Journal of the American Geriatrics Society | 1996

Prevalence of Atrial Fibrillation and Association of Atrial Fibrillation with Prior and New Thromboembolic Stroke in Older Patients

Wilbert S. Aronow; Chul Ahn; Hal Gutstein

Vascular enumeration using antibodies to Factor VIII has been reported to be an independent prognostic indicator of invasive breast carcinoma.


Journal of Clinical Oncology | 1996

Treatment of germ cell cancer with two cycles of high-dose ifosfamide, carboplatin, and etoposide with autologous stem-cell support.

Kim Margolin; James H. Doroshow; Chul Ahn; Victor Hamasaki; Lucille Leong; Robert J. Morgan; James Raschko; Stephen Shibata; George Somlo; Merry Tetef

OBJECTIVE: To correlate atrial fibrillation with the incidence of new thromboembolic (TE) stroke in older patients with and without prior TE stroke.


Bioelectromagnetics | 1997

Electrochemical treatment of mouse and rat fibrosarcomas with direct current

Chung Kwang Chou; J. A. McDougall; Chul Ahn; Nayana Vora

PURPOSEnTo evaluate the activity of two cycles of high-dose ifosfamide, carboplatin, and etoposide (ICE) with autologous hematopoietic progenitor cell support (aHPCS) in patients with poor-prognosis, chemotherapeutically sensitive germ cell cancer.nnnPATIENTS AND METHODSnTwenty patients with germ cell tumor who had persistent disease or relapse from standard-risk or high-risk presentation were entered on this pilot study. The entry criteria included relapsed gonadal and extragonadal germ cell cancer unlikely to be cured by standard salvage therapy but without proven refractoriness to chemotherapy. Treatment consisted of two cycles of ICE chemotherapy with mesna uroprotection and aHPCS. On the first cycle, ifosfamide (IFX), 2 gm/m2; carboplatin, 400 mg/m2; and etoposide, 20 mg/kg, were administered on days -6, -5, and -4. On the second cycle, the doses and schedule of carboplatin and etoposide were identical, and patients with normal renal function received additional IFX, 2 g/m2 on day -3 and 1 g/ m2 on day -2. Mesna, 600 mg/m2 every 6 hours, was given until 24 hours following the final dose of IFX on each cycle, and autologous bone marrow and/or peripheral stem-cells were infused on day 0.nnnRESULTSnAll twenty patients are assessable for toxicity and current disease status. Two patients received only one cycle of therapy, one because of the development of active hepatitis C following cycle 1, and one because of renal insufficiency. No patient died as a result of protocol therapy, and no patient developed debilitating peripheral neuropathy, symptomatic hearing loss, or severe renal insufficiency requiring dialysis. The median time to recovery of > or = 500 neutrophils/microL and platelets > or = 50,000/microL was day +11 and day +15, respectively. The median maximum creatinine was 1.6 mg/dL on each treatment cycle, and there was no other significant organ toxicity. With a median follow-up of 45 months, nine patients are alive and disease-free following protocol chemotherapy. One patient with embryonal cancer developed progressive pulmonary metastases 3 months after completing high-dose therapy, underwent complete resection of lung metastases, and remains disease-free at 63+ months. Eight patients are continuously disease free at 23+ to 70+ months after protocol therapy. Eleven patients died of progressive disease between 4 and 23 months following completion of treatment.nnnCONCLUSIONnThese results compare favorably to other studies in similarly selected patients undergoing salvage therapy with one or two cycles of chemotherapy containing high-dose carboplatin and etoposide with or without cyclophosphamide (CTX) or IFX. The excellent safety and tolerability profile of this regimen and its encouraging activity in poor-prognosis patients make it worthy of further study as part of initial therapy in randomized protocols for high-risk disease and early in the treatment of relapsed germ cell cancer.


American Journal of Cardiology | 1993

Circadian variation of primary cardiac arrest or sudden cardiac death in patients aged 62 to 100 years (mean 82)

Wilbert S. Aronow; Chul Ahn

Electrochemical treatment (ECT) of cancer utilizes direct current to produce chemical changes in tumors. ECT has been suggested as an effective alternative local cancer therapy. However, a methodology is not established, and mechanisms are not well studied. In vivo studies were conducted to evaluate the effectiveness of ECT on animal tumor models. Radiation-induced fibrosarcomas were implanted subcutaneously in 157 female C3H/HeJ mice. Larger rat fibrosarcomas were implanted on 34 female Fisher 344 rats. When the spheroidal tumors reached 10 mm in the mice, two to five platinum electrodes were inserted into the tumors at various spacings and orientations. Ten rats in a pilot group were treated when their ellipsoidal tumors were about 25 mm long; electrode insertion was similar to the later part of the mouse study, i.e., two at the base and two at the center. A second group of 24 rats was treated with six or seven electrodes when their tumors were about 20 mm long; all electrodes were inserted at the tumor base. Of the 24 rats, 12 of these were treated once, 10 were treated twice. and 2 were treated thrice. All treated tumors showed necrosis and regression for both mice and rats; however, later tumor recurrence reduced long-term survival. When multiple treatments were implemented, the best 3 month mouse tumor cure rate was 59.3%, and the best 6 month rat tumor cure rate was 75.0%. These preliminary results indicate that ECT is effective on the radiation-induced fibrosarcoma (RIF-1) mouse tumor and rat fibrosarcoma. The effectiveness is dependent on electrode placement and dosage.

Collaboration


Dive into the Chul Ahn's collaboration.

Top Co-Authors

Avatar

George Somlo

City of Hope National Medical Center

View shared research outputs
Top Co-Authors

Avatar

James Raschko

City of Hope National Medical Center

View shared research outputs
Top Co-Authors

Avatar

Lucille Leong

City of Hope National Medical Center

View shared research outputs
Top Co-Authors

Avatar

Robert J. Morgan

City of Hope National Medical Center

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

James H. Doroshow

City of Hope National Medical Center

View shared research outputs
Top Co-Authors

Avatar

Kim Margolin

City of Hope National Medical Center

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Hector Battifora

City of Hope National Medical Center

View shared research outputs
Top Co-Authors

Avatar

Anthony D. Mercando

City of Hope National Medical Center

View shared research outputs
Researchain Logo
Decentralizing Knowledge