Search results for "JUNCTION"

Walk the Line. The Surgical Highways to the Craniovertebral Junction in Endoscopic Approaches: A Historical Perspective

2018

Background We compiled a comprehensive literature review on the anatomic and clinical results of endoscopic approaches to the craniocervical junction (CVJ) to better contribute to identify the best strategy. Methods An updated literature review was performed in the PubMed, OVID, and Google Scholar medical databases, using the terms “Craniovertebral junction,” “Transoral approach,” “Transnasal approach,” “Transcervical approach,” “Endoscopic endonasal approach,” “Endoscopic transoral approach,” “Endoscopic transcervical approach.” Clinical series, anatomic studies, and comparative studies were reviewed. Results Pure endonasal and cervical endoscopic approaches still have some disadvantages, …

Pre- and postsynaptic effects of muscarinic agonists in the guinea-pig ileum

1980

The effects of several muscarinic agonists on smooth muscle (postsynaptic effect) and on acetylcholine release (presynaptic effect) were compared in the longitudinal muscle-myenteric plexus preparation of the guinea-pig ileum. 1. For release experiments the acetylcholine stores of the preparation were labelled with 3H-choline. Electrical field stimulation in the absence of a cholinesterase inhibitor caused an outflow of tritium that reflected release of 3H-acetylcholine. The agonists oxotremorine, arecaidinepropargylester, methylfurmethide, muscarine, carbachol, arecoline and pilocarpine inhibited the stimulation-induced outflow in a concentration-dependent manner. At the highest concentrat…

Are double potentials markers of a specific zone of the atrioventricular junction in the isolated rabbit heart?

1997

A study is made of the characteristics of the atrial potentials recorded in the Koch triangle and its proximity, their variations on modifying the site of cardiac pacing, and their usefulness as markers of a distinct zone of the AV junction. In 12 isolated and perfused rabbit heart preparations an analysis was made of the endocardial atrial electrograms recorded with a multiple electrode positioned in the AV junction. The electrograms were obtained during spontaneous rhythm and on pacing at the crista terminalis (CT), interatrial septum (IAS), left atrium, and right ventricle. Double potentials were frequently obtained. On pacing at the CT, high-low double potentials (DP [H-L]) were more fr…

Intestinal filtration as a consequence of increased mucosal hydraulic permeability

1980

Two mechanisms have been proposed to explain the secretory action of laxative compounds in the intestine: 1. increase of the intracellular amount of cyclic adenosine monophosphate due to stimulation of the adenylate cyclase system and 2. inhibition of intestinal transfer processes, in particular the Na,K-ATPase activated sodium absorption. In a set of in vivo and in vitro experiments in rat colon it could be demonstrated that dihydroxy bile acids (deoxycholate) and diphenolic laxatives (oxyphenisatin) enhance the hydraulic permeability of the mucosal tissue. The permeability changes take place--and there is good experimental evidence--at the zonulae occludentes which bind the epithelial cel…

Facilitatory and inhibitory muscarine receptors on the rat phrenic nerve: effects of pirenzepine and dicyclomine

1988

Neuronal transmitter stores of the rat phrenic nerve were labelled by an incubation with [3H]choline. Release of [3H]acetylcholine was elicited either by a short (100 pulses, 5 Hz) or by a long (1500 pulses, 5 or 25 Hz) period of electrical nerve stimulation. Pirenzepine and dicyclomine enhanced transmitter release evoked by the short stimulation period. Both antagonists reduced transmitter release evoked by the long stimulation period. Pirenzepine reduced transmitter release at low concentrations (1 nmol/l) whereas a higher concentration was necessary for the enhancing effect; the opposite pattern was found for dicyclomine. A low concentration of oxotremorine (10 nmol/l) enhanced and a hig…

Current Surgical Treatment Standards for Esophageal and Esophagogastric Junction Cancer

2020

A number of different surgical techniques for the treatment of cancer of the esophagus and the esophagogastric junction have been proposed. Guidelines generally recommend a transthoracic approach for esophageal cancer, including Siewert type I tumors. In tumors of the proximal esophageal third, transthoracic esophagectomy may be extended to a three-field approach, including resection of cervical lymph nodes. However, the choice between transthoracic esophagectomy with intrathoracic anastomosis (Ivor Lewis esophagectomy) and the three-incision approach with cervical esophago-gastrostomy (McKeown esophagectomy) remains controversial, with guidelines varying among different countries. Furtherm…

The multidisciplinary management of gastro-oesophageal junction tumours

2016

Abstract Background and scope The management of GOJ cancers remains controversial and may vary between countries. Evidence-based attitudes and guidelines are not easy to elaborate since most of the trials and studies reported mixed cases of oesophageal (both adenocarcinoma and squamous cell tumours), GOJ and gastric cancers. The aim of this expert discussion and position paper is to elaborate practical recommendations that integrate evidence-reported literature and experience-based attitude covering all clinical aspects of GOJ cancer across different specialities and countries in Europe. Methodology Opinion leaders, selected on scientific merit were asked to answer to a prepared set of ques…

Obstrucción funcional de la unión esofagogástrica inducida por opiáceos

2017

Influence of polyunsaturated fatty acids on Cortisol transport through MDCK and MDCK-MDR1 cells as blood-brain barrier in vitro model.

2011

Abstract Transport across the blood–brain barrier is a relevant factor in the pharmacological action of many drugs and endogenous substances whose action site is located in brain. An overactive P-gp has been suggested to be of relevance for the resistance of the HPA system to be suppressed by glucocorticoids, which is one of the best described biological abnormalities in certain types of depression. PUFA acids have shown clinical efficacy in depressed patients and the hypothesis is that these compounds are able to reduce HPA axis activity as this effect has been shown in animal models of depression. The objective of the present work was (1) to characterize Cortisol transport through MDCK an…

Mechanisms of C-reactive protein-induced blood-brain barrier disruption.

2009

Background and Purpose— Increased mortality after stroke is associated with brain edema formation and high plasma levels of the acute phase reactant C-reactive protein (CRP). The aim of this study was to examine whether CRP directly affects blood–brain barrier stability and to analyze the underlying signaling pathways. Methods— We used a cell coculture model of the blood–brain barrier and the guinea pig isolated whole brain preparation. Results— We could show that CRP at clinically relevant concentrations (10 to 20 μg/mL) causes a disruption of the blood–brain barrier in both approaches. The results of our study further demonstrate CRP-induced activation of surface Fcγ receptors CD16/32 fo…