Home About us Contact
|
Home About us Contact | ||
|
|
||
Jugular Vein Catheter (jugular + vein_catheter)
Selected AbstractsVigabatrin extracellular pharmacokinetics and concurrent ,-aminobutyric acid neurotransmitter effects in rat frontal cortex and hippocampus using microdialysisEPILEPSIA, Issue 2 2009Xin Tong Summary Purpose:, To investigate the pharmacokinetic interrelationship of vigabatrin in blood and the brain (frontal cortex vs. hippocampus) and to ascertain the relationship between brain extracellular vigabatrin concentrations and concurrent ,-aminobutyric acid (GABA) concentrations. Methods:, Sprague-Dawley rats were implanted with a jugular vein catheter for blood sampling, and microdialysis probes in the frontal cortex and hippocampus for extracellular fluid (ECF) sampling. Vigabatrin was administered intraperitoneally at two different doses (500 and 1,000 mg/kg), and blood and ECF were collected at timed intervals up to 8 h. Rats were freely moving and behaving. Vigabatrin (sera and ECF) and GABA (ECF) concentrations were measured with use of high performance liquid chromatography (HPLC). Results:, Vigabatrin concentrations in blood rose linearly and dose-dependently, and vigabatrin rapidly appeared in the brain as evidenced by the detection of vigabatrin in the ECF of both the frontal cortex and hippocampus at time of first sampling (15 min). However, frontal cortex concentrations were twofold greater than those of the hippocampus. Furthermore, GABA concentrations increased five-fold in the frontal cortex but were unaffected in the hippocampus. In addition, GABA concentrations began to increase approximately 3 h after vigabatrin administration at a time when vigabatrin concentrations were in exponential decline. Conclusions:, Vigabatrin distribution in the brain is region specific, with frontal cortex concentrations substantially greater than those seen in the hippocampus. Elevation of GABA concentrations did not reflect the concentration profile of vigabatrin but reflected its regional distribution. [source] Ultrasound screening for internal jugular vein thrombosis aids the detection of central venous catheter-related infections in patients with haemato-oncological diseases: a prospective observational studyBRITISH JOURNAL OF HAEMATOLOGY, Issue 6 2003Florian Lordick Summary. To prove the hypothesis that central venous catheter-related thrombosis and infection are associated, 43 haemato-oncological patients with an internal jugular vein catheter underwent ultrasound screening for thrombosis every 4 d. Catheter-related thrombosis was detected in 13/43 patients (30%). Catheter-related infection, as defined by the U.S. Hospital Infection Control Practices Advisory Committee, was found in 14/43 patients (33%) with colonization of the catheter in two patients, exit site infection in eight patients and catheter-related bloodstream infection in four patients. Catheter-related thrombosis and catheter-related infection coincided in 12 patients and were significantly correlated (Fisher's exact test, P < 0·0001). Detection of thrombosis indicated a catheter-related infection with a superior sensitivity (86%vs 57%) and an equivalent specificity (97%) compared with the presence of clinical signs (erythema, tenderness, warmth or swelling). Neutropenia, which occurred in 32 patients, was found in 13/14 patients (93%) with a catheter-related infection and, therefore, seemed to be an important covariate for the development of a catheter-related infection. This study showed a close correlation between catheter-related thrombosis and infection. Ultrasound screening for thrombosis was helpful for detecting catheter-related infection. These findings could be clinically useful for the handling of central venous catheters in patients with an elevated risk of infectious complications. [source] THE NOVEL SELECTIVE TOLL-LIKE RECEPTOR 4 SIGNAL TRANSDUCTION INHIBITOR TAK-242 PREVENTS ENDOTOXAEMIA IN CONSCIOUS GUINEA-PIGSCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 5-6 2009Masamune Kuno SUMMARY 1TAK-242 is a novel compound that suppresses nitric oxide and cytokine production by selectively inhibiting intracellular signals from toll-like receptor (TLR)-4. In the present study, we investigated the effectiveness of TAK-242 against sepsis using an endotoxaemia model in conscious and unrestricted guinea-pigs. Measures examined included muscle tension paralysis of the intestine, blood pressure, high morbidity group box (HMGB)-1 levels and survival rate. 2Tension of the longitudinal muscle of the colon was monitored continuously by telemetry. Arterial blood pressure was monitored via a carotid artery catheter. TAK-242 was administered intravenously through a jugular vein catheter. Guinea-pigs were divided into a control group, given vehicle (placebo emulsion), and the experimental group, administered 3 or 10 mg/kg TAK-242, 1 h before administration of 10 mg/kg lipopolysaccharide (LPS). 3In the control group, the tension of the longitudinal muscle of the colon decreased in a time-dependent manner and blood pressure was reduced, with maximal effects observed 1,3 h after administration of LPS. In the TAK-242-treated group, LPS-induced relaxation of the intestine and hypotension were significantly inhibited. In the control group, HMGB-1 levels were increased after LPS administration and this reaction was significantly blocked in the TAK-242-treated group. Importantly, survival rate was increased after TAK-242 treatment. 4In conlusion, the results of the present study show that TAK-242 inhibited the symptoms associated with endotoxaemia in a guinea-pig model of sepsis and that it may, therefore, be an effective treatment for sepsis. [source] CONTRIBUTION OF PROSTANOID TP RECEPTORS TO THE PRESSOR AND INTRARENAL HAEMODYNAMIC RESPONSE TO ENDOTHELINCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 3 2006Jan Michael Williams SUMMARY 1Previous studies have shown that endothelin (ET)-1 stimulates thromboxane (Tx)A2 production and so we hypothesized that inhibiting prostanoid TP receptors would prevent the pressor and intrarenal haemodynamic response to an acute infusion of ET-1. 2Male Sprague-Dawley rats were anaesthetized with Inactin (Sigma Chemical, St Louis, MO, USA; 50 mg/kg) and catheters were inserted into the femoral artery and vein for recording mean arterial pressure (MAP) and infusion of ET-1 and receptor antagonists, respectively. A jugular vein catheter was used for the infusion of bovine serum albumin (6.2% in saline) during surgery (1.25% bodyweight). The pressor response to a 1 h infusion of ET-1 (6 pmol/kg per min) was determined in rats that had been pretreated with vehicle (0.9% NaCl) or the TP receptor antagonist SQ29548 (2 mg/kg per h). Laser Doppler single-optic fibres were implanted in the left kidney for the measurement of medullary blood flow (MBF) and cortical blood flow (CBF). 3Prostanoid TP receptor blockade completely inhibited the acute pressor response to ET-1; the change in MAP was 14 2% versus -3 4% in vehicle and SQ29548 groups, respectively (P < 0.05). Endothelin-1 reduced CBF (-15.2 3.3%), a response that was not significantly changed by SQ29548 (-6.2 7.6%). Similarly, the ET-1-mediated response in MBF was not altered by the TP receptor antagonist (7.7 4.9 vs 6.5 5.2%). 4To determine the influence of the ETB receptor in modulating the response to ET-1 during TP receptor blockade, additional groups were pretreated with A-192621, an ETB receptor-selective antagonist (10 mg/kg, i.v.). A-192621 potentiated the increase in MAP produced by ET-1 (32 5%; P < 0.05 vs ET-1 alone). SQ29548 significantly inhibited, but did not completely block, the increase in MAP produced by ET-1 during ETB antagonist treatment (18 4%; P < 0.05). Endothelin-1-induced decreases in CBF were significantly enhanced in rats that were pretreated with A-192621, whereas ET-1 also significantly decreased MBF following A-192621 treatment. During ETB receptor blockade, TP receptor inhibition had no effect on the ET-1-mediated response of CBF and MBF. 5These results suggest that TP receptor activation is not involved in the renal haemodynamic responses to ET-1. However, TP receptor activation contributes to the acute pressor response to ET-1, but does not account for the potentiated increase in MAP during ETB receptor blockade. [source] Reinstatement of Ethanol-Seeking Behavior Following Intravenous Self-Administration in Wistar RatsALCOHOLISM, Issue 9 2007Justin T. Gass Background: In animal models of alcoholism, subjects are traditionally trained to self-administer ethanol via the oral route. However, ethanol is also self-administered intravenously (IV), a paradigm which offers several advantages over oral self-administration methods, including immediate delivery to the bloodstream, more rapid onset of pharmacological effects, and elimination of the need to utilize tastants or sweeteners to mask the aversive orosensory properties of ethanol. However, no studies to date have examined reinstatement of ethanol-seeking behavior in animals with a history of IV ethanol self-administration. Methods: Male Wistar rats were implanted with indwelling jugular vein catheters and trained to self-administer ethanol IV (1% v/v solution, equivalent to 1 mg/kg) in an operant lever-pressing paradigm in twice daily 1 hour sessions. Each IV delivery of ethanol was paired with presentation of a light-tone complex stimulus. After stabilization of response patterns, IV self-administration behavior was subjected to extinction procedures. Next, animals were exposed to the three types of stimuli known to reinstate ethanol-seeking behavior: presentation of ethanol-associated cues, a priming dose of ethanol (0.5 g/kg i.p.), or exposure to stress via administration of the anxiogenic compound yohimbine (2.5 mg/kg i.p.) or its corresponding vehicle. Results: During the maintenance phase of self-administration, animals exhibited significantly more presses on the lever that delivered the ethanol solution than the inactive lever, indicating that IV ethanol functioned as a positive reinforcer. Following extinction, it was found that ethanol-seeking behavior could be reinstated by all three types of stimuli (cues, ethanol priming, and yohimbine). Vehicle injection did not affect responding on either lever. Conclusions: Ethanol serves as a reinforcer when self-administered IV, and following extinction, ethanol-seeking behavior can be reinstated by ethanol-associated cues, ethanol priming, or a pharmacological stressor. Thus, reinstatement of ethanol-seeking behavior in animals with a history of IV ethanol self-administration may be a novel animal model of relapse. [source] | ||||||||||