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Biomedical subjects

A K Madan

Publications and source records attributed to A K Madan.

At least 19 recordsLinked to original sources
PubMed2001

Extrapancreatic pseudoaneurysm after pancreas transplantation.

Pseudoaneurysms after pancreatic transplantation are an infrequent event. Repair usually involves removal of the transplant. We describe a patient with a pseudoaneurysm associated with pancreatic transplantation. The pseudoaneurysm originated from the external iliac artery distal to the donor Y-graft anastomosis. Diagnosis was made by duplex ultrasound. Surgical repair was effected through a retroperitoneal incision enabling vascular control. The patient has done well postoperatively, and with 1-year follow-up, continues to have normal renal and pancreatic allograft function.

Aneurysm, False↗
PubMed2001

Predicting anti-HIV activity: computational approach using a novel topological descriptor.

The discriminating power of a novel topological descriptor termed as eccentric adjacency index in the estimation of anti-HIV activity, for a data set of 107 1-[(2-hydroxyethoxy)methyl]-6-(phenylthio)thymine (HEPT) derivatives was investigated in the present study. The value of eccentric adjacency index of each derivative was computed and active range was identified using moving average analysis. Subsequently, each derivative was assigned a biological activity which was then compared with the reported anti-HIV activity. The accuracy of prediction was found to be more than ninety percent in the active range using eccentric adjacency index. The proposed index offers a vast potential for structure-activity/property studies.

Anti-HIV Agents↗
PubMed2001

Age bias: a cause of underutilization of breast conservation treatment.

BACKGROUND: Breast conservation therapy (BCT) has been shown to result i about the same disease control and survival as modified radical mastectomy (MRM) for stage I and II breast cancers. Barriers to using BCT in patients with invasive breast cancer include "physician preference." This study was undertaken to investigate the bias of residents with respect to breast-conserving procedures. METHODS: Internal medicine and surgery residents were instructed about the efficacy of BCT. Subsequently, their opinions were assessed using a questionnaire concerning recommendations for BCT versus MRM as well as breast reconstruction after MRM in similar patients. Chi square tests were used for statistical analysis. RESULTS: Seventy-nine residents (54 medical, 25 surgical) participated. MRM was recommended for 38% of older (> 59 years old) versus 11% of younger patients (< 31 years old), p < 0.01. Furthermore, breast reconstruction was recommended for 96% of younger versus only 70% of older patients (p < 0.01). CONCLUSIONS: Residents are biased against older women in their recommendations for breast conservation and breast reconstruction. Educational efforts to decrease this age bias should be instituted during residency.

Adult↗
PubMed2001

Ageism in medical students' treatment recommendations: the example of breast-conserving procedures.

PURPOSE: Age bias may play a role in physicians' discussions of equivalent therapeutic options with patients, especially in respect to breast-conservation therapy. This study investigated bias based on age (ageism) among physicians-in-training in their treatment recommendations for breast-conserving procedures. METHOD: Second-year medical students responded to a questionnaire concerning recommendations they would make for breast conservation or mastectomies with or without breast reconstruction for eight patients with similar-stage breast cancer. The patients differed by age (older were > or =59 years, younger < or =31 years), race, and marital status. A total of 116 students made 1,146 recommendations. Percentages of the students' recommendations for breast-conservation therapy (BCT) were calculated for the two patient age groups and for the recommendations for breast reconstruction after the patient had already chosen modified radical mastectomy (MRM). Chi-square tests were used for statistical analysis. RESULTS: The students recommended BCT for a significantly higher percentage of younger patients than older patients (86% versus 66%; p<.001). They recommended MRM to 34% of older patients versus 14% of younger patients (p<.001). Furthermore, the students recommended breast reconstruction after MRM to a significantly higher percentage of younger patients than older patients (95% versus 65%; p<.001). CONCLUSIONS: Medical students' recommendations of breast conservation and breast reconstruction showed age bias. Educational efforts should be instituted during the medical school to decrease ageism in students' treatment recommendations.

Adult↗
PubMed2001

Meckel's diverticulum causing cecal volvulus.

Meckel's diverticulum is present in 2 per cent of the population with bowel obstruction as its most common complication. This case report describes an extremely rare complication of a Meckel's diverticulum, a cecal volvulus. The diagnosis of cecal volvulus was made preoperatively on abdominal X-rays; the diagnosis of a Meckel's diverticulum was made intraoperatively. The cecum was found to be twisted around a vitelline band on a broad-based Meckel's diverticulum extending to the umbilicus. The diverticulum was resected. The patient did well postoperatively and was discharged without any difficulty.

Adult↗
PubMed2001

Axillary lymph node status of T1 primary breast cancer in a diverse population.

The utility of level I and II axillary lymph node dissection in women with primary tumors less than 1 cm in diameter has recently received extensive evaluation. Numerous patients undergo axillary lymph node dissection ultimately to discover no pathological involvement. This study investigates the lymph node status in T1 primary breast adenocarcinoma in our diverse patient population. A retrospective evaluation of patients treated at the Medical Center of Louisiana at New Orleans and the Tulane University Medical Center with breast adenocarcinoma less than or equal to 2 cm was performed. Demographic data and pathological reports were reviewed to obtain breast lesion size and lymph node status. One hundred sixteen patients were found to have T1 lesions. Ethnic distribution was African American 66 per cent; Caucasians 30 per cent; Hispanic 2 per cent; and Asian 3 per cent. Whereas no patients with T1a lesions had positive lymph nodes, 11 per cent of patients with T1b lesions and 36 per cent of patients with T1c lesions had positive lymph nodes. However, in our patient population no patients with tumors less than 1.0 cm. in diameter had positive lymph nodes. Although this may be due to our relatively small sample size axillary lymph node dissection may be unnecessary in this select patient population. For patients with lesions 1.0 cm and greater an axillary lymph node dissection seems to add necessary information for correct treatment in a small percentage of patients. The use of lymphatic mapping with sentinel axillary lymph node biopsy may reduce the number of unnecessary axillary dissections in early breast cancer.

Adenocarcinoma↗
PubMed2001

Noncompliance of health care workers with universal precautions during trauma resuscitations.

BACKGROUND: Universal precautions during resuscitations are mandated by hospital regulations. We documented adherence to universal precautions during trauma resuscitations at our level I trauma center. METHODS: During trauma resuscitations, a medical student using an elevated viewing platform observed health care workers (HCWs) for the use of barrier precautions (BPs): gloves, masks, gowns, and eyewear. Only HCWs having direct patient contact were included. The purpose of the observation was not disclosed to those being observed. RESULTS: In 12 resuscitations involving 104 HCWs, none had 100% compliance with BPs. Compliance rates for individual BPs were gloves, 98%; eyewear (any type), 52%; gowns, 38%; masks, 10%; and eyewear (with side protectors), 9%. Resuscitations in which bleeding was observed involved 59 HCWs with 38% compliance; only 2 used full BPs. No difference in compliance rates occurred during the study period. CONCLUSIONS: Experienced trauma care HCWs are cavalier regarding blood-borne disease exposure risks. Measures to encourage (or force) compliance are needed.

Emergency Medicine↗
PubMed2001

Magnification views of mammography decrease biopsy rates.

Mammography is a valuable tool for screening and has increased early detection of breast cancer. Magnification views are commonly used to further elucidate suspicious changes seen on routine mammograms. The effect of magnification views and their utility have not been studied regarding the influence on treatment strategies. All patients who had magnification views performed along with their mammogram at Tulane University Medical Center over a one-year period were included. Patient charts were reviewed for mammogram readings, recommendations, and any biopsy results. The original mammograms without the magnification views were given to a physician who was blinded to the final results of the magnification views for a recommendation of whether or not to biopsy the lesion. These recommendations were compared with the results with actual recommendations. Magnification views were performed on 127 patients. After the additional magnification views were taken 27 per cent (34 of 127) of patients had biopsies performed. Biopsy results revealed benign findings in 71 per cent and nonbenign findings (lobular carcinoma in situ, ductal carcinoma in situ, or carcinoma) in 29 per cent. On the basis of the recommendations without magnification views 64 per cent of patients would have had biopsies performed. Magnification views decreased the biopsy rates by 58 per cent (P < 0.001; chi2 tests). Magnification views can help decrease the number of biopsies performed for suspicious small areas on mammograms. Their judicious use can help decrease unnecessary procedures, patient anxiety, and cost. Magnification views are useful to help surgeons and radiologists best screen for breast cancer.

Biopsy↗
PubMed2000

Treatment of antibody-mediated accelerated rejection using plasmapheresis.

Accelerated antibody-mediated rejection is believed to be due to an anamnestic response of an allograft recipient to donor antigens. Few reports have demonstrated successful reversal of this type of rejection, and no consensus exists for either diagnosis or treatment. Accelerated antibody-mediated rejection was suspected on the basis of clinical findings and confirmed by cytotoxic and flow crossmatches, and leukocyte antibody screens. Serial crossmatches and antibody screens were performed through post-transplant day 112. Plasmapheresis was performed on post-transplant days 1, 2, 4, 6, 12, 14, 20, and 28. The duration of treatment was determined by the cytotoxic crossmatch results. We present a case of successfully treated accelerated antibody-mediated rejection using plasmapheresis and aggressive immunosuppression. Serial crossmatch and leukocyte antibody screen results are presented that confirm the production of anti-donor antibody and demonstrate the effectiveness of the treatment protocol in eliminating detectable levels of the anti-donor antibody. At 6 months post-transplant, the patient has a serum creatinine of 1.1 and has not had any additional rejection episodes or infectious complications. The protocol suggested in this paper allows for rapid diagnosis, institution of treatment, and monitoring the efficacy of treatment, providing the basis for follow-up clinical trials.

Antibodies↗
PubMed2000

Insulin-like growth factor I receptor antagonism augments response to chemoradiation therapy in colon cancer cells.

BACKGROUND: Colorectal cancer remains one of the most prevalent malignancies in the United States. Improvement in local disease control is seen when 5-fluorouracil (5-FU) is used in combination with pelvic irradiation for rectal adenocarcinoma. The frequent overexpression of insulin-like growth factor I receptor (IGF-I-R) in rectal adenocarcinoma suggests that inhibition of the signal transduction pathway may be a novel approach to enhance tumor response. This investigation seeks to define the role of IGF-I-R antagonism, using monoclonal antibody alpha-IR3, in augmenting cytotoxicity to adjuvant chemoradiation therapy for adenocarcinoma of the rectum. MATERIALS AND METHODS: SW 480 colon cancer cells were cultured to semiconfluent conditions with dose titrations performed for 5-FU to determine that the IC(50) (inhibitory concentration of 50% of the cells) was 0.5 microg/ml. The IC(50) for 5-FU was reassessed in the presence of IGF-I. Experimental groups included colon cancer cells combined with 5-FU; 6-MeV external beam radiation (100-500 cGy); and alpha-IR-3. RESULTS: The addition of 100 ng/ml IGF-I 1 h prior to 5-FU or radiation significantly blunted the expected cytotoxicity, resulting in a 10-fold increase in the IC(50) (from 0.5 to 5 microg/ml). Receptor antagonism using the monoclonal antibody alpha-IR-3 (100-400 ng/ml) produced a dose-dependent increase in cytotoxicity compared with 5-FU alone. The addition of radiation produced synergistic amplification of this response. CONCLUSIONS: IGF-I-R activation blocks the expected cytotoxic effects of 5-FU and external beam radiation. Receptor antagonism increased the cytotoxic response of chemoradiation therapy. These data suggest the utility of inhibiting IGF-I-R signal transduction in the treatment of rectal adenocarcinoma.

Antibodies, Monoclonal↗
PubMed2000

Connective eccentricity index: a novel topological descriptor for predicting biological activity.

A simple, adjacency-cum-path length based, topological descriptor termed the connective eccentricity index has been conceptualized and its discriminating power investigated with regard to antihypertensive activity. A data set consisting of 81 derivatives of N-benzylimidazole was selected for the present investigation. These derivatives are potent, competitive, and nonpeptide angiotensin II receptor antagonists. The value of connective eccentricity index for each derivative was computed and active range identified. Subsequently, each derivative was assigned a biological activity that was compared with the reported antihypertensive activity. The results obtained using connective eccentricity index were better than the corresponding values obtained using Balaban's mean square distance index. The accuracy of prediction was found to be about 80% in the active range using connective eccentricity index.

Angiotensin Receptor Antagonists↗
PubMed2000

Extra-anatomic bypass grafting for aortoesophageal fistula: a logical operation.

Aortoesophageal fistula (AEF) is an uncommon cause of upper gastrointestinal hemorrhage. Usually, but not always, patients present with a small sentinel bleed followed by a variable interval of apparent resolution, and then they experience a massive exsanguinating hemorrhage. The variable interval of time after the sentinel bleed is the period in which most AEFs resulting from thoracic aortic aneurysm have been successfully treated. Although only a few successful cases have been reported in the literature, most describe an in situ repair. We describe treatment of a late-presenting AEF due to a thoracic aneurysm with an extra-anatomic bypass graft for the aortic repair.

Aged↗
PubMed2000

Higher risk of HIV transmission during trauma resuscitations.

Despite an appreciation of the potential for blood borne pathogen exposure, compliance of universal precautions is low. While reports of HIV positive rates in trauma patients have varied from 0.15% to 7.8%, the estimated prevalence of HIV in Louisiana is 0.32%. We made use of two unique, complimentary data sources: the Trauma Registry and the HIV/AIDS Reporting System database of known HIV positive patients to estimate the relative prevalence of HIV which may indicate an increase risk of blood borne pathogen transmission to health care workers during trauma resuscitations. In one year, 1031/1159 patients were evaluated from the Trauma Registry Database and 22 similar patients (2.13%) were found in both the Trauma Registry and the HIV/AIDS Reporting System Database. Our prevalence is an indicator of the minimum risk since it is based on only reported cases of HIV and justifies intensification of education and enforcement of the practice of universal precautions.

Adolescent↗
PubMed1999

Esophageal Doppler ultrasound monitor versus pulmonary artery catheter in the hemodynamic management of critically ill surgical patients.

BACKGROUND: The pulmonary artery (PA) catheter has been used to determine hemodynamic indices; however, it has recently been criticized. This study was undertaken to evaluate an esophageal Doppler monitor (EDM) as a possible replacement for PA catheter in critically ill, mechanically ventilated patients. METHODS: EDM and PA catheters were placed in patients in the surgical intensive care units (n = 14, 118 matched sets of data). PA catheter and EDM measurements, including corrected flow time (FTc,) a measure of preload, were obtained. Pearson correlation (r) was analyzed to compare PA catheter and EDM measurements, and a nonlinear regression model was used to describe Starling Relationships. RESULTS: Cardiac output correlated between EDM and PA catheter (r = 0.6; p < 0.001). FTc correlated more strongly with cardiac output than did pulmonary capillary wedge pressure. (FTc: r2 = 0.27; p < 0.001; cardiac output: r2 = 0.04; p = 0.06). CONCLUSION: Corrected flow time is a better indicator of preload than pulmonary capillary wedge pressures. EDM seems to be at least as useful as PA catheter in managing the hemodynamic status of critically ill surgical patients.

Adult↗
PubMed1999

Alcohol and drug use in victims of life-threatening trauma.

OBJECTIVE: Alcohol and drug use has been implicated as a contributing factor to all types of trauma. This investigation seeks to determine the prevalence of alcohol and drug use in patients who are victims of life-threatening injuries and the association of alcohol and drug use with intentional trauma. METHODS: The Medical Center of Louisiana at New Orleans (Charity Campus) trauma registry was used to identify patients sustaining life-threatening injuries that presented to our American College of Surgeons Level 1 trauma center over a 6-month period. Serum ethanol levels and urine toxicology were assessed at initial presentation for all patients. RESULTS: A total of 557 patients were evaluated. Seventy percent (n = 319) of tested patients (n = 450) had positive serum ethanol and/or urine toxicology results. Male gender (75% vs. 55%; p < 0.001) was associated with positive screens; ethnicity was not. No difference in hospital days or mortality was seen between positive and negative screens. Victims of intentional trauma showed a higher percent of positive screens (80% vs. 63%; p < 0.005). CONCLUSION: These data suggest that alcohol and drug use is associated with life-threatening injury, especially intentional injury. Prevention of substance abuse is essential for the prevention of trauma.

Adolescent↗
PubMed1999

Changes in compliance predict pulmonary morbidity in patients undergoing abdominal plication.

The incidence and severity of the effects of pulmonary compliance changes were investigated in patients undergoing abdominal plication surgery. A total of 20 healthy adults scheduled for abdominal plication surgery who had no significant history of pulmonary disease and 20 adults scheduled for nonabdominal, nonthoracic surgery (control group) underwent general endotracheal anesthesia; neuromuscular blockade was confirmed with electrical twitch monitoring. Before abdominal plication, the mean airway compliance was measured under total neuromuscular blockade at 33.4 +/- 2.1 ml/cm water, which was not significant when compared with control patient values. After abdominal plication was performed, the mean airway compliance was remeasured under total neuromuscular blockade; it was significantly decreased at 24.0 +/- 1.8 ml/cm water when compared with values for control patients (32.6 +/- 1.6 ml/cm) and with preplication values. Patients with airway compliance changes of less than 4 ml/cm water (when compared with preplication pulmonary mechanics) had far less incidence of atelectasis, requirements for supplemental oxygen at 24 hours or longer, or hypoxia when compared with patients with compliance changes of greater than 4 ml/cm water. Patients with compliance changes greater than 9 ml/cm water had the highest incidence of pulmonary morbidity. These data suggest that significant changes in pulmonary compliance occur after abdominal plication and that these airway compliance changes are associated with a clinically increased incidence of pulmonary morbidity in the postoperative period.

Abdominal Muscles↗
PubMed1998

Comparison of simulated patient and didactic methods of teaching HIV risk assessment to medical residents.

INTRODUCTION: Physicians need to be well trained in HIV risk assessment interview skills. Little has been written in the literature concerning training methods for this specialized interview. METHODS: One model to teach the HIV risk assessment interview has been developed and has been used to teach third-year medical students. We compared this interactive model, which uses simulated patients to teach HIV Risk Assessment, to a didactic one. Twelve medical residents were taken through either the interactive session or the didactic session. Pre-post changes from questionnaires were calculated to determine any differences in sessions. Also, Objective Structured Clinical Examinations (OSCEs) were used to grade all residents 2 weeks after their sessions. RESULTS: All pre-post changes were calculated and no statistically significant differences were seen (P > 0.50). OSCE interpersonal skills scores and content scores were calculated. The interactive group had statistically significantly higher scores (P < 0.05). CONCLUSION: The data supports the conclusion that an interactive method is more effective to use to train HIV risk assessment interview skills to medical residents when compared to the didactic method.

Adult↗