Sevoflurane is equivalent to isoflurane for attenuating bupivacaine-induced arrhythmias and seizures in rats

The effects of sevoflurane on bupivacaine toxicity have not been defined. The purpose of this study was to investigate the effects of sevoflurane and isoflurane on bupivacaine-induced arrhythmias and seizures in rats. Thirty-seven Sprague-Dawley rats received bupivacaine intravenously at a constant rate of 2 mg.kg-1.min-1 until both arrhythmias and seizures occurred while electrocardiogram (ECG) and electroencephalogram (EEG) recordings were made. The cumulative doses of bupivacaine inducing arrhythmias and seizures were determined in the presence of 1 minimum alveolar anesthetic concentration (MAC) of sevoflurane (sevoflurane group, n = 14) or isoflurane (isoflurane group, n = 10) and in the absence of anesthetic (control group, n = 13). The cumulative doses of bupivacaine inducing arrhythmias and seizures were larger in the sevoflurane and isoflurane groups than in the control group and were similar in the sevoflurane and isoflurane groups. These results indicate that sevoflurane and isoflurane attenuate bupivacaine-induced arrhythmias and seizures in rats.     

Abnormal sensitivity to duodenal lipid infusion in patients with functional dyspepsia

BACKGROUND AND OBJECTIVES: Patients with functional dyspepsia exhibit increased sensitivity to gastric distension (mechanoreceptors) and to meals rich in fat (chemoreceptors). The aim of this study was to test whether these patients were abnormally sensitive to intraduodenal lipid, and whether this stimulus altered gastric mechanosensitivity. METHODS AND DESIGN: Experiments were conducted on 10 patients and 10 healthy controls. The stomach was distended with a flaccid bag during duodenal infusion of either 10% Intralipid or 0.9% saline. Intragastric pressure was recorded continuously, and the participants were asked to report gastric sensations of fullness and discomfort. RESULTS: Intragastric pressure profiles during distension were similar in patients and controls. Lipid decreased intragastric pressure and reduced phasic contractility. Patients showed enhanced sensitivity to gastric distension compared with controls during both saline and lipid infusions. In the controls, threshold volumes for fullness and discomfort were higher during lipid than saline infusion. In the patients, the sensation of fullness occurred at lower volumes during lipid infusion, whereas discomfort occurred at similar volumes but lower intragastric pressures. Most patients experienced nausea and bloating and three patients vomited during lipid infusion, but remained asymptomatic during saline infusion. Controls reported no symptoms during either infusion. CONCLUSION: Dyspeptic patients have increased sensitivity to both gastric distension and intraduodenal lipid. In contrast to controls, lipid sensitizes their stomachs to distension.     

Adenosine-induced transient cardiac asystole enhances precise deployment of stent-grafts in the thoracic or abdominal aorta

BACKGROUND: Anaphylaxis to the bite of Diptera and specifically the bite of the Tabanidae family (horsefly) have been sparsely documented. The coexistent hypersensitivity to both the order Diptera and Hymenoptera has not been documented. METHODS: We present a patient who experienced anaphylaxis to both insect species. Venom skin testing and RAST revealed sensitivity to several members of the Hymenoptera order. Prick, intradermal and RAST with whole body extracts of Tabanidae species is also documented in this patient. Twenty patients who are sensitive to Hymenoptera and have been bitten by horseflies but have had no reaction to the horsefly bite were used as controls. RESULTS: An anaphylactic reaction to horsefly bite has been documented in a 56-year-old white male. This patient also demonstrated evidence of anaphylactic reaction to Hymenoptera envenomation. In controls consisting of 20 patients with Hymenoptera sensitivity, there was no clinical history of reaction to horsefly bite despite the presence of positive prick and/or positive intradermal tests and/or positive RAST to mixed Tabanidae species extract. CONCLUSIONS: Skin testing to horsefly by prick and/or intradermal testing using whole body insect extract is not useful in making a diagnosis of Tabanidae hypersensitivity. RAST using Tabanidae species as antigen is similarly useless in making a diagnosis of Tabanidae hypersensitivity. In vivo and in vitro diagnosis of horsefly hypersensitivity may be achieved when the salivary gland antigen of the horsefly becomes available.     

Dietary flavonoids reduce lipid peroxidation in rats fed polyunsaturated or monounsaturated fat diets

We investigated the influence of dietary flavonoids on alpha-tocopherol status and LDL peroxidation in rats fed diets enriched in either polyunsaturated fatty acids (PUFA) or monounsaturated fatty acids (MUFA). Diets equalized for alpha-tocopherol concentrations were or were not supplemented with 8 g/kg diet of flavonoids (quercetin + catechin, 2:1). After 4 wk of feeding, plasma lipid concentrations were lower in rats fed PUFA than in those fed MUFA with a significant correlation between plasma alpha-tocopherol and cholesterol concentrations, r = 0.94, P < 0. 0001). Dietary lipids influenced the fatty acid composition of VLDL + LDL more than that of HDL or microsomes. The resistance of VLDL + LDL to copper-induced oxidation was higher in rats fed MUFA than in those fed PUFA as assessed by the lower production of conjugated dienes and thiobarbituric acid reactive substances (TBARS) and by the >100% longer lag time for dienes production. (P < 0.0001). Dietary flavonoids significantly reduced by 22% the amounts of dienes produced during 12 h of oxidation in rats fed diets rich in PUFA and lengthened lag time 43% in those fed MUFA. Microsomes of rats fed MUFA produced approximately 50% less TBARS than those of rats fed PUFA (P < 0.0001) and they contained more alpha-tocopherol in rats fed MUFA than in those fed PUFA with higher values (P < 0. 0001) in both groups supplemented with flavonoids (P < 0.0001). Our findings suggest that the intake of dietary flavonoids is beneficial not only when diets are rich in PUFA but also when they are rich in MUFA. It seems likely that these substances contribute to the antioxidant defense and reduce the consumption of alpha-tocopherol in both lipoproteins and membranes.     

Formoterol inhaled as dry powder or via pressurized metered-dose inhaler in a cumulative dose-response study

Formoterol administered by a dry-powder (DP) capsule inhaler was compared with a pressurized metered-dose inhaler (pMDI) with regard to bronchodilating and systemic effects. The study used a double-blind, crossover, double-dummy technique. Twelve patients with moderate reversible asthma in a stable phase were examined on two separate study days, and the inhalers were given in randomized order. After baseline measurements, increasing doses of formoterol were given at intervals of 75 min. FEV1 and heart rate and tremor measurements were repeated after each dose, and the doses were 12 + 12 + 24 + 48 micrograms, giving a total dose of 96 micrograms. The peak expiratory flow rate (PEFR) was recorded in the morning before the first dose, after the last dose, and then repeatedly at home until 19 h after the last dose. There was an equal increase in ventilatory capacity at each dose level, independent of inhaler device. Repeated PEFR measurements after the last dose did not reveal any differences in duration of effect. There was a slight but statistically significant increase in heart rate and tremor after the highest doses of the DP formulation compared to the pMDI. These systemic effects can probably be explained by the reduced oral deposition of the aerosol caused by using a spacer. This study indicates that the DP and pMDI formulations of formoterol are equipotent in bronchodilation.     

Pre- to postelection shifts in presidential rhetoric: Impression management or cognitive adjustment.

Used content analysis to assess the conceptual or integrative complexity of pre- and post-election policy statements of 20th-century American presidents. Two hypotheses were tested. According to the impression management hypothesis, presidents present issues in deliberately simplistic ways during election campaigns but in more complex ways upon assuming office when they face the necessity of justifying sometimes unpopular decisions to skeptical constituencies. According to the cognitive adjustment hypothesis, presidents gradually become more complex in their thinking during their tenure in office as they become increasingly familiar with high-level policy issues. Results support only the impression management position. The complexity of presidential policy statements increased sharply immediately after inauguration but did not increase with length of time in office. Complexity of policy statements also significantly declined in reelection years. (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Potentiation of sufentanil by clonidine in PCEA with or without basal infusion

The purpose of the present study was to observe whether inflammatory mediators, such as: Prostaglandin E2 (PGE2), Bradykinin (BK), Histamine (HIS), Platelet active factor (PAF) and 5-hydroxytryptamine (5-HT), directly triggered the release of CGRP from perivascular nerves in isolated rat mesenteric arterial bed. The results showed that PGE2 (1-100 mumol/L) and BK (5-10 mumol/L) caused time- and concentration-dependent CGRP release, but HIS, PAF and 5-HT did not show significant effects. Our data indicate that PGE2 and BK are the major inflammatory mediators in triggering the release of CGRP from the perivascular CGRP-containing nerve.     

Pretreatment with allopurinol diminishes pancreatography-induced pancreatitis in a canine model

Granulocytic ehrlichia 16S rDNA was amplified for the 1st time from an Ixodes ricinus (Linne) tick collected in Europe. Sequence analysis of polymerase chain reaction products from the 16S rRNA gene demonstrated the organism from which it originated to be closely related to the agent of human granulocytic ehrlichiosis, an emerging disease that was recently described in the United States; Ehrlichia phagocytophila, the agent of tick-borne fever of ruminants in Europe; and Ehrlichia equi. the agent of the worldwide equine granulocytic ehrlichiosis. These granulocytic ehrlichiae have been associated with Ixodes spp. ticks that may act as vectors. It remains to be determined if each of these granulocytic ehrlichiae, that may constitute variants of the same species, is responsible for a specific disease in animals and in humans.     

Age-related changes in the lipid metabolism of Fisher 344 rats

Lipid metabolism of male Fisher 344 rats aged 2-24 months was studied. Serum and liver cholesterol levels did not display the age-related gradual increase seen in other rat strains. An increase in the serum plus liver cholesterol pool from 2 to 6 months was followed by a plateau through 18 months and then another increase at 24 months of age. The triglyceride pool increased from 2 to 6 months and then remained unchanged through 24 months of age. Cholesterol synthesis from acetate decreased 50% between 2 and 9 months and fell only slightly through 24 months of age. Assay of 3-hydroxy-3-methyl glutaryl Coenzyme A (HMG-CoA) reductase showed a similar pattern but did not decrease further after 9 months of age. Cholesterol 7alpha hydroxylase activity was not significantly altered by age. These age- and strain-related differences present an opportunity for a comparative study of the aging process using the parameters of lipid metabolism as indicators.     

Ontogeny of heart rate response to milk infusion in infant rats as a function of level of deprivation.

Recorded the heart rate (HR) responses of infant Sprague-Dawley rats aged 8, 11, 14, and 17 days during the intraoral infusion of milk. Ss were deprived for various periods of time prior to the start of testing. Results revealed a transition from HR deceleration to HR acceleration between 8 and 14 days of age, with the magnitude of the response varying directly with the degree of deprivation. A follow-up experiment was run to demonstrate that the observed HR changes were not a result of the termination of infusion. Implications for a transition from infant to adult feeding systems as well as the development of a somatic cardiac linkage are discussed. (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Region-specific DNA synthesis in brains of F344 rats following a six-day bromodeoxyuridine infusion

Prolonged exposure to certain alkylating chemicals induces glial and meningeal tumours in rats, probably resulting from DNA damage to dividing neural cells. The present work evaluated DNA synthesis in the brains of untreated, young adult male F344 rats in order to define a BrdUrd infusion protocol to more adequately assess proliferation in slowly dividing neural cell populations. BrdUrd (2.5 to 160 mg/ml) was administered for 6 days via subcutaneous osmotic pumps. Clinical toxicity was not observed at any dose. The labelling index (LI; % of cells per brain area that incorporated BrdUrd) and unit length labelling index (ULLI; % of cells per meningeal length that incorporated BrdUrd) were calculated for selected regions by counting labelled neural cells in defined areas of the right hemisphere in coronal brain sections. Intensely stained cells were numerous in the cerebral subependymal layer (LI = 35.8%); scattered in cerebral white matter tracts (e.g. corpus callosum and internal capsule; LI = 6.2%) as well as cerebral (ULLI = 4.2%) and cerebellar (ULLI = 3.6%) meninges; and rare in the hippocampus (LI > 0.1%). Mildy stained cells were dispersed in the pons (LI = 2.1%), deep cerebral (LI = 1.8%) and cerebellar (LI = 1.0%) grey matter, and thalamus (LI = 0.3%). Phenotypically, BrdUrd-positive cells in neuropil were glial cell precursors and their progeny, while those associated with meninges were usually located in the superficial subarachnoid space and appeared to be fibrocytes. Using BrdUrd infusion, LI for glial precursors at these sites ranged from two- to 10-fold higher than those reported previously after a brief parenteral pulse dose. These data indicate that continuous BrdUrd infusion for 6 days by subcutaneous osmotic pump is an efficient means of labelling neural cells throughout the brain.     

Compartmental shifts of calcium and magnesium as a result of swimming and swimming training in rats

To describe accurately the mineral changes (Ca and Mg) provoked by swimming, the aims of this study were to analyze those tissues that, with regard to their mineral content, can better classify individuals performing both swimming until exhaustion and swimming as training and to know the shifts of these minerals between different tissues after a single session of swimming until exhaustion and after training. Wistar rats were distributed into 12 groups, six male and six female (N = 10): 1) control rest group (CR); 2) trained rest group (TR); 3) control exercise group (CE); 4) trained exercise group (TE); 5) control recovery group (CER) and 6) trained recovery group (TER). The most informative tissues of Ca and Mg compartmental shifts during exercise have been determined. Discriminant analysis selected heart Ca, muscle Ca and bone Ca, bone Mg, erythrocyte Mg, and serum Mg as the most significant variables. The animals were classified by means of two canonical axes: the first one relates to training situation and sex, and the second one shows the special characteristics of trained male rats. Another independent discriminant analysis applied to male and female groups separately showed that the first canonical axis (control/trained) is basically defined by heart Ca, bone Ca, and erythrocyte Mg (male), and by heart Ca, bone Ca, and bone Mg (female), while the second axis, related to the exercise situations, is defined by the serum Mg levels in both sexes. We think that discriminant analysis is a statistical method capable of explaining physiological processes and classifying individuals performing exercises of different length. It suggests that the homeostasis of Ca and Mg is somewhat different for males and females. Serum magnesium must be considered to distinguish exercise situations. The analysis of these tissues could inform us about the mineral status of the rats and then we could correct possible deficiencies in our research. In this work we have only found different mineral redistributions among tissues. The trained animals have a better mineral recovery capacity than the untrained ones. Training has a different physiological repercussion in male and female rats on the basis of their respective maximal swimming times after training and their mineral behavior.     

Intranigral iron infusion in the rat. Acute elevations in nigral lipid peroxidation and striatal dopaminergic markers with ensuing nigral degeneration

Iron is known to induce lipid peroxidation and recent evidence indicates that both iron and lipid peroxidation are elevated in the substantia nigra in Parkinson's disease (PD). To test whether excess intranigral iron induces lipid peroxidation, we infused an iron citrate solution (0.63 nmol in 0.25 microL) into the rat substantia nigra and measured nigral thiobarbituric acid reactive products at 1-h, 1-d, 1-wk, and 1-mo postinfusion. In a separate group of iron-infused animals, histologic analysis within the substantia nigra through 1-mo postinfusion was accomplished by thionine- and iron-staining, with concurrent assessment of striatal neurochemical markers. Concentrations of nigral thiobarbituric acid reactive products were significantly elevated at 1 h and 1 d in iron-infused animals compared to vehicle-infused and unoperated animals, with a return to control values by 1 wk. Similarly, striatal dopamine turnover was acutely elevated, suggesting damage to dopaminergic neurons, which was confirmed histologically. Although iron-staining within the iron diffusionary area was increased through the postinfusion month, there was an apparent progression of the cellular character of staining from predominantly neuronal to reactive glial and finally to oligodendroglial by 1 mo postinfusion. This progression of cellular iron-staining may indicate a shifting of infused iron to a more bound unreactive form, thus explaining only an acute elevation in lipid peroxidation through 1 d following intranigral iron infusion. The data indicate that damage to nigral neurons induced by iron infusion is transciently associated with a marker of oxidative damage and supports the possibility that iron-induced oxidative stress contributes to the pathogenesis of PD.