Analysis of risk factors for perifocal oedema after endovascular embolization of unruptured intracranial arterial aneurysms

Background

Endovascular embolization is a treatment of choice for the management of unruptured intracranial aneurysms, but sometimes is complicated with perianeurysmal oedema. The aim of our study was to establish incidence and outcomes of perianeurysmal oedema after endovascular coiling of unruptured intracranial aneurysms, and to reveal possible risk factors for development of this potentially serious complication.

Methods

In total 119 adult patients with endovascular embolization of unruptured intracranial aneurysm (performed at Department for Interventional Neuroradiology, Clinical Center, Kragujevac, Serbia) were included in our study. The embolizations were made by electrolite-detachable platinum coils: pure platinum, hydrophilic and combination of platinum and hydrophilic coils. Primary outcome variable was perianeurysmal oedema visualized by magnetic resonance imaging (MRI) 7, 30 and 90 days after the embolization.

Results

The perianurysmal oedema appeared in 47.6% of patients treated with hydrophilic coils, in 21.6% of patients treated with platinum coils, and in 53.8% of those treated with mixed type of the coils. The multivariate logistic regression showed that variables associated with occurrence of perianeurysmal oedema are volume of the aneurysm, hypertension, diabetes and smoking habit. Hypertension is the most important independent predictor of the perianeurysmal oedema, followed by smoking and diabetes.

Conclusions

The results of our study suggest that older patients with larger unruptured intracranial aneurysms, who suffer from diabetes mellitus and hypertension, and have the smoking habit, are under much higher risk of having perianeurysmal oedema after endovascular coiling.     

Capecitabine cardiotoxicity--case reports and literature review

This study presents 3 case reports of patients who experienced anginous pain during treatment with capecitabine. The interruption of capecitabine and sublingual or intravenous nitroglycerine treatment lead to recovery. Rechallenge of capecitabine with dose reduction of 30% lead to repeated anginous pain in 2 patients. Treatment with capecitabine had been replaced with weekly bolus 5FU-LV, without further cardiotoxicity. The literature contains data from about 50 patients who experienced cardiotoxicity during capecitabine treatment. The most frequent manifestations of capecitabine cardiotoxicity included: anginous pain in 38/53 (71.7%), arrhythmia in 6/53 (11.3%), myocardial infarction in 6/53 (11.3%). Cardiotoxicity of capecitabine lead to death in 6/53 (11.3%) patients. Risk factors for cardiotoxicity are associated with the grade 4 and the fatal outcome of cardiotoxicity (p = 0.035, p = 0.015), but not with the symptom recurrence upon capecitabine rechallenge (p = 0.18). The combination chemotherapy regimens are associated with the grade 4 of cardiotoxicity (p = 0.048), but not with the fatal outcome (p = 0.3). Rechallenge of capecitabine lead to symptoms recurrence in 10/16 patients. Neither the dose reduction of capecitabine (p = 0.18) nor the additional medical prophylaxis (p = 0.37) were important for the outcome of capecitabine rechallenge.     

Croatia: legal regulation of doctors

Accompanying changes in the way health services in Croatia are organised has been a significant change in the way the medical profession is regulated. In 1995 the Croatian Medical Chamber was established, with legal powers. The responsibilities of physicians to their patients are spelled out in considerable detail. Most of these responsibilities are matched by provisions in Croatia's criminal law. Croatia has about 10,000 doctors and dentists and since 1998 19 cases have been resolved by the Medical Chamber and its commissions. Public health providers offer protection in medical negligence cases but this could change as more market-oriented health-care provision is introduced. In 1997 and 1998 only 60 malpractice claims under the criminal law were brought and most of those were dismissed.     

Cardiac sympathetic afferent cell bodies are located in the peripheral nervous system of the cat

Studies of the stellate ganglion and middle cervical ganglion indicate that sympathetic efferent nerve activity can be modified by peripheral excitatory inputs and that these neural connections may function as pathways for a peripheral reflex at the level of the thoracic sympathetic ganglia. This excitatory synaptic input could have a soma in either the central or the peripheral nervous system. A study was designed to determine whether chronic decentralization (3 weeks) of the stellate ganglion in cats would 1) abolish sympathetic cardiac afferent nerve activity recorded at the stellate cardiac nerve and 2) abolish local thoracic reflexes that are generated by stimulation of peripheral nerves. The ansae subclaviae, T3 and T4 rami, and stellate ganglion were also examined by electron microscopy for the extent of Wallerian degeneration. Afferent cardiac activation of the axon collaterals arising from cell bodies located in the dorsal root ganglia was abolished due to degeneration. However, sympathetic afferent nerve activity from the left ventricular receptors was still present and was recorded from the stellate cardiac nerve in all cats. Cardiac receptors were sensitive to mechanical distortion, increases in the left ventricular pressure, and epicardial application of veratrine hydrochloride. These data imply that 1) cardiovascular afferent input to the stellate ganglion persists following chronic decentralization and 2) the sensory neurons are located in the peripheral sympathetic nervous system. Thus, we find that regulation of the heart occurs in part via thoracic ganglia, independently of the central nervous system.     

Role for hydrogen peroxide in flow-induced dilation of human coronary arterioles

Flow-induced dilation (FID) is dependent largely on hyperpolarization of vascular smooth muscle cells (VSMCs) in human coronary arterioles (HCA) from patients with coronary disease. Animal studies show that shear stress induces endothelial generation of hydrogen peroxide (H2O2), which is proposed as an endothelium-derived hyperpolarizing factor (EDHF). We tested the hypothesis that H2O2 contributes to FID in HCA. Arterioles (135+/-7 micro m, n=71) were dissected from human right atrial appendages at the time of cardiac surgery and cannulated with glass micropipettes. Changes in internal diameter and membrane potential of VSMCs to shear stress, H2O2, or to papaverine were recorded with videomicroscopy. In some vessels, endothelial H2O2 generation to shear stress was monitored directly using confocal microscopy with 2',7'-dichlorofluorescin diacetate (DCFH) or using electron microscopy with cerium chloride. Catalase inhibited FID (%max dilation; 66+/-8 versus 25+/-7%; P<0.05, n=6), whereas dilation to papaverine was unchanged. Shear stress immediately increased DCFH fluorescence in the endothelial cell layer, whereas treatment with catalase abolished the increase in fluorescence. Electron microscopy with cerium chloride revealed shear stress-induced increase in cerium deposition in intimal area surrounding endothelial cells. Exogenous H2O2 dilated (%max dilation; 97+/-1%, ED50; 3.0+/-0.7x10(-5) mol/L) and hyperpolarized HCA. Dilation to H2O2 was reduced by catalase, 40 mmol/L KCl, or charybdotoxin plus apamin, whereas endothelial denudation, deferoxamine, 1H-(1,2,4)-oxadiazole-[4,3-a]quinoxalin-1-one, or glibenclamide had no effect. These data provide evidence that shear stress induces endothelial release of H2O2 and are consistent with the idea that H2O2 is an EDHF that contributes to FID in HCA from patients with heart disease. The full text of this article is available at http://www.circresaha.org.     

Comparison of lidocaine and bupivacaine depression of sinoatrial nodal activity during hypoxia and acidosis in adult and neonatal guinea pigs

High blood concentrations of local anesthetics are cardiotoxic. The aim of this study was to compare the effects of lidocaine and bupivacaine on the intrinsic pacemaker activity of in vitro sinoatrial nodal cells of the adult and neonatal guinea pig in the presence and absence of hypoxia and acidosis. Fifteen pairs of adult (greater than 80 days old) and neonatal (0-3 days old) hearts were isolated. Nodal tissues were suffused with Krebs-Ringer solution at 37 degrees C and exposed to increasing concentrations of either lidocaine (0.05-0.8 mM) or bupivacaine (0.01-0.4 mM). The suffusate was equilibrated either with 5% CO2, 95% O2 (pH 7.40, PO2 482 torr) or with 12% CO2, 88% N2 (pH 7.01, PO2 58 torr). Transmembrane action potentials were recorded from sinoatrial nodal cells and impulse intervals were converted to rates. We found that hypoxia and acidosis alone reduced rates in both adults and neonates, and that the reduction was additive to the effects of local anesthetics. Bupivacaine was 4-5 times more potent in decreasing rates than was lidocaine in both age groups. Lidocaine was about twice as effective in depressing neonatal rates as adult rates, and bupivacaine caused cessation of pacemaker activity in a greater percentage of nodes than did lidocaine. Our results demonstrate, in vitro, that the neonatal sinoatrial node is more sensitive to lidocaine and bupivacaine than is the adult node, that bupivacaine is more potent in depressing and stopping nodal activity, and that hypoxia and acidosis enhance pacemaker depression caused by these agents.(ABSTRACT TRUNCATED AT 250 WORDS)     

Sympathetic and Mesenteric Venous Responses to Baroreceptor or Chemoreceptor Stimulation during Epidural Anesthesia in Rabbits

Background: Baroreceptor and chemoreceptor reflexes maintain homeostasis through mechanisms that involve sympathetic activation. Because sympathetic control of the mesenteric veins plays a central role in hemodynamic responses to stress, the effects of epidural blockade on reflex responses to hypoxia and bilateral carotid occlusion (BCO) were examined by monitoring direct measures of splanchnic sympathetic neural traffic and mesenteric venous capacitance.

Methods: Rabbits were studied during alpha-chloralose anesthesia and mechanical ventilation. Sympathetic efferent nerve activity to the mesenteric vessels was measured by surgically placed electrodes, and mesenteric venous diameter was measured by videomicroscopy. Heart rate and mean arterial pressure were monitored by intraarterial cannulation. Intraluminal venous pressure was monitored by a servo-null micropressure technique. Responses were recorded during repeated administration of three different stresses, FI O2 = 0% for 40 s, FI O2 = 11% for 2.5 min, and BCO for 60 s. Animals received either thoracolumbar epidural blockade (0.4 ml/kg lidocaine 1.5%; n = 7) or 15 mg/kg intramuscular lidocaine (n = 7).

Results: Hypoxia and BCO produced sympathetic stimulation and active constriction of mesenteric veins. Epidural anesthesia accentuated the mean arterial pressure decrease from FI O2 of 0%, caused the 11% response to FI O2 to become depressor instead of pressor, and decreased the pressor effect BCO. Sympathetic efferent nerve activity and venous diameter responses to hypoxia and BCO were attenuated or eliminated.     

Prediction of peak-to-background ratio in gamma-ray spectrometry using simplex optimized artificial neural network.

An artificial neural network (ANN) model was used for the prediction of peak-to-background ratio (PBR) as a function of measurement time in gamma-ray spectrometry. In order to make the ANN model with good predictive power, the ANN parameters were optimized simultaneously employing a variable-size simplex method. Most of the predicted and the experimental PBR values for eight radionuclides ((226)Ra, (238)U, (235)U, (40)K, (232)Th, (134)Cs, (137)Cs, and (7)Be) commonly detected in soil samples agreed to within +/-19.4% of the expanded uncertainty and 2.61% of average bias.     

Stimulation by 17 alpha-hydroxyprogesterone of glycoprotein and glycosaminoglycan synthesis in human placenta in vitro

The incorporation of 14C-glucosamine into glycoproteins (GP) and glycosaminoglycans (GAG), of 3H-leucine into protein, and the hexuronic acid (HA) content of polymerized GAG was determined in incubated placental tissue. In placentae of earlier gestational age (GA), incorporation of 14C-glucosamine was 2.6 times greater than other at 38-39 weeks GA. 19 of 26 placentae at 38-39 weeks GA responded by one or more parameters when incubated with 0.5-3 microM 17 alpha-OH-progesterone (17OHP). Those which did not respond were all of earlier GA; the placental content of GAG decreased in these from 31.1 +/- 1.8 nmol HA/mg protein to 16.4 +/- 1.5 nmol in placentae of GA 38-39 weeks. In the latter, 17OHP increased GAG by 42.5% to 24.4 +/- 2.5 nmol HA/mg protein in a 2-hour incubation. Progesterone, oestriol, cortisol and testosterone were without effect. It is concluded that synthesis of placental GAG decreases toward the end of gestation, but can be increased by 17OHP specifically. This indicates that 17OHP is a biologically active steroid and might have a role in maintaining placental function.