Noninvasive assessment of coronary vasodilation using magnetic resonance angiography

OBJECTIVES: The purpose of this study was to investigate the use of coronary magnetic resonance angiography (MRA) for assessing human epicardial coronary artery vasodilation. BACKGROUND: Coronary vasodilation plays a vital role in the human coronary circulation. Previous studies of epicardial coronary vasodilation have used invasive coronary angiography. Coronary MRA may provide an alternative noninvasive method to directly assess changes in coronary size. METHODS: Thirty-two subjects were studied: 12 patients (age 55 +/- 18 years) and 20 healthy subjects (age 34 +/- 4 years). High-resolution multi-slice spiral coronary MRA (in-plane resolution of 0.52 to 0.75 mm) was performed before and after sublingual nitroglycerin (NTG). Quantitative analysis of coronary vasodilation was performed on cross-sectional images of the right coronary artery (RCA). A time-course analysis of coronary vasodilation was performed in a subset of eight subjects for 30 min after NTG. Signal-to-noise ratio was also measured on the in-plane RCA images. RESULTS: Coronary MRA demonstrated a 23% increase in cross-sectional area after NTG (16.9 +/- 7.8 mm2 to 20.8 +/- 8.9 mm2, p <0.0001), with significant vasodilation between 3 and 15 min after NTG on time-course analysis. The MRA measurements had low interobserver variability (< or =5%) and good correlation with X-ray angiography (r=0.98). The magnitude of vasodilation correlated with baseline cross-sectional area (r=0.52, p=0.03) and age (r=0.40, p=0.019). Post-NTG images also demonstrated a 31% improvement in coronary signal-to-noise ratio (p = 0.002). CONCLUSIONS: Nitroglycerin-enhanced coronary MRA can noninvasively measure coronary artery vasodilation and is a promising noninvasive technique to study coronary vasomotor function.     

Rapid diagnosis of spontaneous bacterial peritonitis with leukocyte esterase reagent strips in a European and in an American center

BACKGROUND: Timely diagnosis and treatment of spontaneous bacterial peritonitis (SBP) are essential to survival. The purpose of the present paper was to evaluate leukocyte esterase reagent strips (Nephur-Test and MultistixSG10) in the bedside diagnosis of SBP. METHODS: Patients with cirrhotic ascites were prospectively included in France (center 1) and in the USA (center 2). Paracenteses were performed on admission and repeated as indicated. Bedside reagent strip testing was performed on the ascitic fluid and compared to manual cell count with differential and ascitic fluid culture. In center 1, the Nephur-Test was tested in all cases, with dual testing with MultistixSG10 in a subgroup. In center 2, all cases had dual testing. Spontaneous bacterial peritonitis was defined as a polymorphonuclear ascites count > or =250/microL. RESULTS: A total of 184 samples was obtained in 76 patients. Center 1 included 151 samples from 53 patients. Seven samples had SBP, obtained in six patients. Center 2 included 33 samples from 23 patients. Six samples had SBP, obtained in five patients. The sensitivity, specificity, positive and negative predictive value of the reagent strips were as follows. Center 1/Nephur-Test: 86%, 100%, 100%, 99%; center 1/MultistixSG10: 100%, 100%, 100%, 100%; center 2/Nephur-Test: 100%, 92.5%, 75%, 100%; center 2/MultistixSG10: 83%, 96%, 83%, 96%. CONCLUSION: Leukocyte esterase reagent strips may provide a rapid bedside diagnosis of SBP.     

Feedback and the mini clinical evaluation exercise

We studied the nature of feedback given after a miniCEX. We investigated whether the feedback was interactive; specifically, did the faculty allow the trainee to react to the feedback, enable self-assessment, and help trainees to develop an action plan for improvement. Finally, we investigated the number of types of recommendations given by faculty. One hundred and seven miniCEX feedback sessions were audiotaped. The faculty provided at least 1 recommendation for improvement in 80% of the feedback sessions. The majority of the sessions (61%) involved learner reaction, but in only 34% of the sessions did faculty ask for self-assessment from the intern and only 8% involved an action plan from the faculty member. Faculty are using the miniCEX to provide recommendations and often encourage learner reaction, but are underutilizing other interactive feedback methods of self-assessment and action plans. Programs should consider both specific training in feedback and changes to the miniCEX form to facilitate interactive feedback.     

Ice cores record significant 1940s Antarctic warmth related to tropical climate variability

Although the 20th Century warming of global climate is well known, climate change in the high-latitude Southern Hemisphere (SH), especially in the first half of the century, remains poorly documented. We present a composite of water stable isotope data from high-resolution ice cores from the West Antarctic Ice Sheet. This record, representative of West Antarctic surface temperature, shows extreme positive anomalies in the 1936–45 decade that are significant in the context of the background 20th Century warming trend. We interpret these anomalies—previously undocumented in the high-latitude SH—as indicative of strong teleconnections in part driven by the major 1939–42 El Niño. These anomalies are coherent with tropical sea-surface temperature, mean SH air temperature, and North Pacific sea-level pressure, underscoring the sensitivity of West Antarctica's climate, and potentially its ice sheet, to large-scale changes in the global climate.     

Mechanism of recurrence after radiofrequency catheter ablation of atrial fibrillation guided by complex fractionated atrial electrograms

Background A better understanding of the mechanisms of recurrent atrial fibrillation (AF) after radiofrequency ablation of complex, fractionated atrial electrograms (CFAEs) may be helpful for refining AF ablation strategies. Methods and results Electrogram-guided ablation (EGA) was repeated in 30 consecutive patients (mean age = 59 ± 8 years) for recurrent paroxysmal AF, 10 ± 4 months after the first ablation. During the first procedure, CFAEs were targeted without isolating all pulmonary veins (PVs). During repeat ablation, all PVs and the superior vena cava (SVC) were mapped with a circular catheter and the left atrium was mapped for CFAEs. EGA was performed until AF was rendered noninducible or all identified CFAEs were eliminated. During repeat ablation, ≥1 PV tachycardia was found in 83 PVs in 29 of the 30 patients (97%). Among these 83 PVs, 63 (76%) had not been completely isolated previously. During repeat ablation, drivers originating in a PV or PV antrum were identified only after infusion of isoproterenol (20 μg/min) in 12 patients (40%). At 9 ± 4 months of follow-up after the repeat ablation procedure, 21 of the 30 patients (70%) were free from recurrent AF and flutter without antiarrhythmic drugs. Conclusions Recurrence of AF after EGA is usually due to PV tachycardias. Therefore, it may be preferable to systematically map and isolate all PVs during the first procedure. High-dose isoproterenol may be helpful to identify AF drivers.     

Hospital Costs, Resource Characteristics, and the Dynamics of Death for Hospitalized Gastroenterology Patients

The federal Medicare diagnosis-related group (DRG) hospital payment system has been on-line for 5 yr with no major adverse effects on either access or quality of care. The hospital industry contends that DRGs are underpaying for hospital care, especially for certain types of patients. Analysis of 2,500 gastroenterology patients by outcome (i.e., survivors vs mortalities) demonstrated that the 122 mortalities had a much greater intensity of hospital resource utilization, and generated substantial financial risk under DRG pricing schemes, compared with the 2,378 survivors. Only mortalities that occurred within 1 wk of admission to the hospital were profitable under DRGs. A long hospital length of stay (LOS) for mortalities was very unprofitable (mortalities with more than a 60-day LOS generated $20,210 loss per patient). Emergency gastroenterology admissions who died had greater financial risk under DRGs, compared to nonemergency mortalities. Those mortalities referred to gastroenterology from other clinical services tended to have greater resource utilization and financial risk under DRGs, compared with nonreferred mortalities. These data suggest significant inequities in the current DRG prospective payment system vis-a-vis gastrotenterology mortalities. Predictive variables of greater hospital resource utilization for gastroenterology mortalities include longer hospital lengths of stay, emergency admission, and referral from another clinical service. If equity of DRG payment is not improved by the federal government, certain groups of patients likely to be mortalities may suffer a decline in access and/or the quality of medical care in the future.     

Obstetric anal sphincter injury: prospective evaluation of incidence

PURPOSE: An obstetrically damaged anal sphincter is the principal cause of the development of fecal incontinence in otherwise healthy females. Reports suggest that such damage complicates as many as 35 percent of primiparous vaginal deliveries, with 13 percent of first-time mothers becoming symptomatic. In maternity units delivering 3,000 patients annually, it would follow that 390 symptomatic patients would develop new symptoms each year. This incidence of dysfunction does not reflect current clinical practice. We have investigated this discrepancy to establish the actual incidence of anal sphincter trauma associated with childbirth. METHODS: During a six-week period, 159 females (105 primiparous and 54 para-I) were prospectively assessed postnatally using a standardized symptom questionnaire, endoanal ultrasound, and anal manometry. This group constituted 84 percent of all eligible deliveries occurring in the unit during the study period. RESULTS: One patient developed fecal urgency after this delivery; there were no reports of fecal incontinence. Anal sphincter injuries were identified ultrasonically in 6.8 percent of primiparous patients, 12.2 percent of para-I patients having vaginal deliveries, and 83 percent of patients having forceps deliveries overall. Manometric data provided confirmatory evidence, with significantly reduced maximum squeeze pressures in patients with a disrupted anal sphincter (P<0.0005). CONCLUSIONS: A symptom questionnaire is inadequate to identify anal sphincter injuries. The incidence of sphincter injury in relation to vaginal delivery has been overestimated in previous published work. This study demonstrates that the true incidence is 8.7 percent overall and that symptoms of sphincter dysfunction are uncommon this is in keeping with current clinical practice.     

Resident recognition of open-angle glaucoma

To test an educational intervention’s effect on improving detection of glaucoma by direct ophthalmoscopy, 14 medicine residents examined five patients, two with ophthalmoscopic changes of glaucoma and three with normal fundi. The residents observed a standardized slide/narrative educational intervention reviewing glaucomatous ophthalmoscopic changes and then re-examined the same patients eight to 12 weeks later. The intervention’s odds of improving residents’ diagnostic impression were significant (OR=2.2; 95% CI=1.3–36), with significant improvement in sensitivity (p=0.02) and a trend toward improved specificity. These findings confirm that the diagnosis of glaucomatous ocular changes on eye examinations by medicine residents can be improved with a brief educational intervention. Presented in abstract form at the annual meeting of the Society of General Internal Medicine, Medical Education Section, April 29–May 1, 1992, Washington, DC, and at the Southern regional meeting of the Society of General Internal Medicine, Medical Education Section, January 29–31, 1992, New Orleans, Louisiana.     

Recurrent rectal prolapse

PURPOSE: The aim of this study was to assess the clinical and functional outcome of surgery for recurrent rectal prolapse and compare it with the outcome of patients who underwent primary operation for rectal prolapse. METHODS: All patients who underwent surgery for rectal prolapse were evaluated for age, gender, procedure, anorectal manometry and electromyography findings, and morbidity. The results for patients who underwent surgery for recurrent rectal prolapse were compared with a group of patients matched for age, gender, surgeon, and procedure who underwent primary operations for rectal prolapse. RESULTS: A total of 115 patients underwent surgery for rectal prolapse. Twenty-seven patients, 10 initially operated on at this institution and 17 operated on elsewhere, underwent surgery for recurrent rectal prolapse. These 27 patients were compared with 27 patients with primary rectal prolapse operated on in our department. In the recurrent rectal prolapse group, prior surgery included rectopexy in 7 patients, Delorme's procedure in 7 patients, perineal rectosigmoidectomy in 7 patients, anal encirclement procedure in 4 patients, and resection rectopexy in 2 patients. Operations performed for recurrence were perineal rectosigmoidectomy in 14 patients, resection rectopexy in 8 patients, rectopexy in 2 patients, pelvic floor repair in 2 patients, and Delorme's procedure in 1 patient. There were no statistically significant differences between the groups in preoperative incontinence score (recurrent rectal prolapse, 13.6±7.8vs. rectal prolapse, 12.7±7.2; range, 0–20) or manometric or electromyography findings, and there were no significant differences in mortality (0vs. 3.7 percent), mean hospital stay (5.4±2.5vs. 6.9±2.8 days), anastomotic complications (anastomotic stricture (0vs. 7.4 percent), anastomotic leak (3.7vs. 3.7 percent) and wound infection (3.7vs. 0 percent)), postoperative incontinence score (2.8±4.8vs. 1.5±2.7), or recurrence rate (14.8vs. 11.1 percent) between the two groups at a mean follow-up of 23.9 (range, 6–68) and 22 (range, 5–55) months, respectively. The overall success rate for recurrent rectal prolapse was 85.2 percent. CONCLUSION: The outcome of surgery for rectal prolapse is similar in cases of primary or recurrent prolapse. The same surgical options are valid in both scenarios.Funded in part by a generous grant from the Eleanor Naylor Dana Charitable Trust Fund and the Caporella Family.Poster presentation at the meeting of The American Society of Colon and Rectal Surgeons, Philadelphia, Pennsylvania, June 22 to 26, 1997.     

Short-Chain Fatty Acids Induce Cytoskeletal and Extracellular Protein Modifications Associated with Modulation of Proliferation on Primary Culture of Rat Intestinal Smooth Muscle Cells

Short-chain fatty acids are the main end products of bacterial fermentation of carbohydrates. Their role on the metabolism and biology of colonocytes is now well characterized. However, the functional consequences of their presence on intestinal smooth muscle cells remain poorly studied. We aimed to assess the effect of different short-chain fatty acids on ileal and colonic smooth muscle cells in primary culture and on A7R5 line. Butyrate (above 0.1 mM) inhibited A7R5 cell proliferation, while at low concentration (0.05 to 0.5 mM) butyrate significantly stimulated the proliferation of ileal and colonic myocytes in primary culture. An inhibition was observed at higher concentrations. Collagenous and noncollagenous protein synthesis was stimulated by butyrate. Moreover, butyrate stimulated actin and myosin expression. Thus, butyrate, which is produced by dietary fiber fermentation, may affect intestinal muscles by directly acting at the molecular level on myocytes.