The effects of A 5-HT1A receptor agonist and antagonist on the 5-hydroxytryptamine release in the central nucleus of the amygdala: a microdialysis study with flesinoxan and WAY 100635

The modulation of extracellular 5-hydroxytryptamine (5-HT) in the central nucleus of the amygdala (CeA) by 5-HT_1A receptors was studied by intracerebral microdialysis in awake and freely moving rats. Local administration of 1 μM tetrodotoxin (TTX), 60 mM K⁺ and perfusion with Ca²⁺-free Ringer containing EGTA confirmed that the major part of dialysate 5-HT levels from the CeA is of neuronal origin. Administration of 300 nM of RU 24969, a 5-HT_1B receptor agonist, through the probe into the CeA decreased dialysate 5-HT levels to 67.2% of the baseline value. Systemic administration of the 5-HT_1A receptor agonists 8-OH-DPAT and flesinoxan dose-dependently decreased 5-HT levels in the CeA. The effect of 0.3 mg/kg of flesinoxan could be completely antagonized by systemic administration of 0.05 mg/kg WAY 100635, a 5-HT_1A receptor antagonist. WAY 100635 alone had only minimal effects at this dose. These data show that a major part of the extracellular 5-HT in the CeA stems from 5-HT neurons and that the amount of 5-HT released into this brain region can be modulated by 5-HT_1A receptors. Received: 11 September 1996 / Accepted: 25 November 1996     

Taking anti-neutrophil cytoplasmic antibody (ANCA) testing beyond the limits.

The application of anti-neutrophil cytoplasmic antibody (ANCA)testing has received much interest since ANCA were discovered[1] and since they were reported to be useful in both the diagnosisand monitoring of disease activity in Wegener's granulomatosis(WG) [2]. Although there is little doubt that the recognitionof the association between the presence of ANCA and active vasculitishas had a very positive influence on research on the pathogenesisand treatment of ANCA-associated diseases (reviewed by Savage[3]), there are reasons to worry about the application of thisrecently gained knowledge in clinical practice. In this commentthe problems with the clinical application of ANCA tests arecategorized for the sake of clarity as (i) standardization problems,(ii) difficulties with application of the test in the appropriate     

Anastomotic pseudoaneurysm after aorto-coronary bypass grafting

A patient with a pseudoaneurysm at the site of the distal anastomosis of a saphenous vein coronary bypass graft is described. The aneurysm was resected. To our knowledge this is the first report of this complication after coronary bypass surgery.     

Does flecainide regain its antiarrhythmic activity after electrical cardioversion of persistent atrial fibrillation?

OBJECTIVES: The purpose of this study was to evaluate the hypothesis that presumed reversion of electrical remodeling after cardioversion of atrial fibrillation (AF) restores the efficacy of flecainide. BACKGROUND: Flecainide loses its efficacy to cardiovert when AF has been present for more than 24 hours. Most probably, the loss is caused by atrial electrical remodeling. Studies suggest electrical remodeling is completely reversible within 4 days after restoration of sinus rhythm (SR). METHODS: One hundred eighty-one patients with persistent AF (median duration 3 months) were included in this prospective study. After failure of pharmacologic cardioversion by flecainide 2 mg/kg IV (maximum 150 mg in 10 minutes) and subsequent successful electrical cardioversion, we performed intense transtelephonic rhythm monitoring three times daily for 1 month. In case of AF recurrence, a second cardioversion by flecainide was attempted as soon as possible. RESULTS: AF recurred in 123 patients (68%). Successful cardioversion by flecainide occurred only when SR had been maintained for more than 4 days (7/51 patients [14%]). Failure to cardiovert was associated with a prolonged duration of the recurrent AF episode and concurrent digoxin use. Multivariate logistic regression confirmed that successful cardioversion was determined by digoxin use (odds ratio [OR] 0.093, P = .047) and by the interaction between the duration of SR and the (inverse) duration of recurrent AF (OR 6.499, P < .001). When flecainide was administered within 10 hours after AF onset and the duration of SR was greater than 4 days, the success rate was 58%. CONCLUSIONS: Flecainide recovers its antiarrhythmic action after cardioversion of AF. However, successful pharmacologic cardioversion occurs only after SR has lasted at least 4 days and is expected only for recurrences having duration of a few hours. Immediate pharmacologic cardioversion of AF recurrence may be a worthwhile strategy for management of persistent AF.     

Serum-sickness-like illness as a complication after streptokinase therapy for acute myocardial infarction

We report a case of serum-sickness-like illness in a 47-year-old patient who received early high-dose intravenous and intracoronary streptokinase following acute myocardial infarction. The picture comprised severe arthralgias, fever, an urticarial rash and marked elevation of circulating immune complexes. This case represents a rare complication of streptokinase therapy.     

Multispectral characterization of tissues encountered during laparoscopic colorectal surgery

AimsThis study investigated the feasibility of automated differentiation between essential tissue types encountered during laparoscopic colorectal surgery using spectral analysis.MethodsWide band (440–1830 nm) spectra were collected using an optical fiber probe and spectrometer from freshly explanted, ex vivo, human colonic specimens. These data were normalized at 810 nm (an isobestic wavelength for hemoglobin and oxy-hemoglobin) and mathematically analyzed using total principal component regression (TPCR).Results929 spectra were collected from specimens of 19 patients, distinguishing 5 tissue types: mesenteric fat (MF, n = 269), blood vessels (BV, n = 377), colonic tissue (CT, n = 213), ureter (UR, n = 10) and tumorous tissue in colon (TT, n = 60). For each individual tissue type the distinctive ability was determined against all other tissue types pooled as a group. Paired probability density function (PDF) of “tissue” (centered around label 1) versus “all other pooled tissues” (centered around label 0) and the cumulative distribution function (CDF) at label crossover value 0.5 was determined for each tissue type (MF: CDF = 0.99 [SD = 0.19]; BV: CDF = 0.95 [SD = 0.29]; CT: CDF = 0.98 [SD = 0.22]; UR: CDF = 0.99 [SD = 0.09]; TT: CDF = 0.99 [SD = 0.18]).ConclusionAutomated spectral differentiation of blood vessel, ureter, mesenteric adipose tissue, colonic tissue and tumorous tissue in colon, is feasible in freshly explanted human colonic specimens. These results may be exploited for further steps toward multi- or hyperspectrally enhanced in vivo (laparoscopic) surgical imaging.     

Are enzymatic tests good indicators of coronary reperfusion?

OBJECTIVE--To assess the accuracy of four enzymatic tests, including early release rates of creatine kinase and alpha-hydroxybutyrate dehydrogenase, in assessing coronary reperfusion after thrombolytic therapy. DESIGN--A prospective clinical trial identifying patients with a successful thrombolytic treatment. PATIENTS--Eighty nine patients with acute myocardial infarction were studied. Arteriography showed a closed infarct related artery in all of them. Reperfusion due to thrombolysis occurred in 74 patients and there was no reperfusion in 15 patients. RESULTS--The 74 patients showing coronary reperfusion had a significantly shorter time to peak creatine kinase activity, higher early release rates for creatine kinase and alpha-hydroxybutyrate dehydrogenase, and a more rapid release of alpha-hydroxybutyrate dehydrogenase (ratio of cumulative release of alpha-hydroxybutyrate dehydrogenase during the first 24 hours to that 72 hours after infarction). All these differences were statistically significant (p less than 0.001). Optimum cut off levels were determined with decision level plots and the accuracy of the four enzymatic tests was calculated. Accuracy was low for all four tests (73%, 70%, 70%, and 82%). CONCLUSION--None of the four enzymatic tests accurately predicted the perfusion state of the infarct related coronary artery after thrombolysis. These tests cannot be used reliably in routine clinical practice as non-angiographic markers of coronary reperfusion.     

The use of a self-expanding stent as palliation or before elective surgery in patients with obstructive colorectal carcinoma

OBJECTIVE: To evaluate the use of colorectal stents. DESIGN: Retrospective. METHOD: Data were collected on all patients treated at the Deventer Hospital, the Netherlands, between 1 April 1996 and 31 December 2003 in whom the placement of a self-expanding colorectal stent was attempted. Each patient's physician was contacted to inquire about the patient's status, including quality of life with the stent in situ. RESULTS: Stent placement was attempted in 57 patients as palliation (n = 45) or before elective surgery (n = 12). Of the 57 patients, 29 were men and 28 were women, and the mean age was 71 years (range: 46-94). All patients had colorectal carcinoma, except 1 patient with stenosis following ischaemic colitis. Passage of air and faeces occurred immediately after stent expansion in 55 of the 57 patients (96%). Perforation during stent placement occurred in 2 patients, who subsequently underwent colostomy. 4 additional patients required a colostomy due to stent migration within a few hours or days after placement (n = 3) or obstruction by tumor growth after 65 days (n = 1). Patients in the palliative group had an acceptable quality of life. Those who received a stent before elective surgery were able to undergo resection, did not require colostomy, and had no postoperative complications. One patient did not undergo surgery because of extensive metastases. CONCLUSION: A colorectal stent can be used in the palliative treatment of terminal patients with colorectal carcinoma before colostomy is considered. Experiences with stents before elective surgery were also positive.