Subselective embolisation in management of JNA

Role of Embolisation in preoperative management of Nasopharyngeal angiofibroma is well established in present day therapeutic modalities. An improvised technique i.e., subselective embolisation has been provided by Interventional radiologists to fortify the therapeutic results. This study compares the final outcome of seven cases, four of which were embolised pre operatively. Each case was dealt with varying surgical approaches.     

Transcatheter Aortic Valve Implantation in the Elderly: Who to Refer?

In recent years, experience with transcatheter aortic valve implantation has led to improved outcomes in elderly patients with severe aortic stenosis (AS) who may not have previously been considered for intervention. These patients are often frail with significant comorbid conditions.     

Depolarization-induced release of endocannabinoids by murine dorsal motor nucleus of the vagus nerve neurons differentially regulates inhibitory and excitatory neurotransmission

Numerous studies, focused on the hypothalamus, have recently implicated endocannabinoids (EC) as orexigenic factors in the central control of food intake. However, the EC system is also highly expressed in the hindbrain autonomic integrator of food intake regulation, i.e. the dorsal vagal complex (DVC). Previous studies have shown that exogenous cannabinoids, by acting on cannabinoid 1 receptor (CB1R), suppress GABAergic and glutamatergic neuronal transmission in adult rat dorsal motor nucleus of the vagus nerve (DMNV), the principal efferent compartment of the DVC. However, no endogenous release of EC has been demonstrated in DVC to date. Using patch-clamp techniques on mouse coronal brainstem slices, we confirmed that both inhibitory and excitatory neurotransmission were depressed by WIN 55,212-2, a CB1R agonist. We demonstrated that DMNV neurons exhibited a rapid and reversible depolarization-induced suppression of electrically evoked GABAergic IPSCs (eIPSCs), classically known as DSI (depolarization-induced suppression of inhibition), while spontaneous or miniature IPSCs activity remained unaltered. Further, no depolarization-induced suppression of glutamatergic eEPSCs (DSE) occurred. Our results indicate that DSI was blocked by SR141716A (Rimonabant), a selective CB1R antagonist, and was dependent on calcium elevation in DMNV neurons, suggesting a release of EC in the DVC. Moreover, the analysis of the paired-pulse ratio, of the coefficient of variation and of the failure rate of eIPSCs support the fact that EC-mediated suppression of GABAergic inhibition takes place at the presynaptic level. These results show for the first time that DMNV neurons release EC in an activity-dependent manner, which in turn differentially regulates their inhibitory and excitatory synaptic inputs.     

彩色室壁动力技术小剂量多巴酚丁胺负荷试验检测冬眠心肌与病理学检查对比的实验研究

目的: 探讨彩色室壁动力技术(CK)小剂量多巴酚丁胺超声心动图负荷试验(CK-DSE) 检测冬眠心肌(HM)的价值.材料和方法: 22只犬结扎冠状动脉造成实验性心肌缺血损伤的动物模型.应用CK-DSE检测动物模型的心肌梗塞区心内膜运动幅度/非梗塞区心内膜运动幅度比值(AMI/ANMI),与病理组织切片显示冬眠心肌面积/梗塞区总面积的比值(ATAM/ATIM)进行对比分析.结果: 本实验成功地建立11只实验性心肌缺血损伤的动物模型,CK-DSE检测冬眠心肌的敏感性、特异性和准确性分别为90%、80%和83%.CK-DSE检测AMI/ANMI比值,与ATAM/ATIM具有较好的相关关系(r=0.75).结论: CK-DSE能准确地检出心肌梗死后存活的冬眠心肌,是定量检测梗塞区内冬眠心肌的较好方法.     

The CB1 cannabinoid receptor C-terminus regulates receptor desensitization in autaptic hippocampal neurones

BACKGROUND AND PURPOSE

The cannabinoid CB₁ receptor is the chief mediator of the CNS effects of cannabinoids. In cell culture model systems, CB₁ receptors both desensitize and internalize on activation. Previous work suggests that the extreme carboxy-terminus of this receptor regulates internalization via phosphorylation of residues clustered within this region. Mutational analysis of the carboxy-terminus of CB₁ receptors has demonstrated that the last six serine/threonine residues are necessary for agonist-induced internalization. However, the structural determinants of CB₁ receptor internalization are also dependent on the local cellular environment. The importance of cell context on CB₁ receptor function calls for an investigation of the functional roles of these residues in neurones.

EXPERIMENTAL APPROACH

To determine the structural requirements of CB₁ internalization in neurones, we evaluated the signalling properties of carboxy-terminal mutated CB₁ receptors expressed in cultured autaptic hippocampal neurones, using electrophysiological methods.

KEY RESULTS

CB₁ receptors transfected into CB₁ knockout neurones signalled and desensitized as did wild-type neurones, allowing us to test specific CB₁ receptor mutations. Deletion of the last 13 residues yielded a CB₁ receptor that inhibited excitatory postsynaptic currents but did not desensitize. Furthermore, mutation of the final six serine and threonine residues to alanines resulted in a non-desensitizing receptor. In contrast, CB₁ receptors lacking residues 419–460, leaving the last 14 residues intact, did desensitize.

CONCLUSIONS AND IMPLICATIONS

The distal thirteen residues of CB₁ receptors are crucial for their desensitization in cultured neurones. Furthermore, this desensitization is likely to follow phosphorylation of serines and threonines within this region.

LINKED ARTICLES

This article is part of a themed section on Cannabinoids in Biology and Medicine. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.165.issue-8. To view Part I of Cannabinoids in Biology and Medicine visit http://dx.doi.org/10.1111/bph.2011.163.issue-7     

Surgical treatment of advanced heart failure: alternatives to heart transplantation and mechanical circulatory assist devices

Although orthotopic heart transplantation is the gold standard for definitive surgical treatment of end-stage heart failure, other operative therapies exist for dealing with severe systolic left ventricular dysfunction. The choice of surgical intervention depends on the etiology and functional characteristics of the patient's ventricular dysfunction. In patients with ischemic cardiomyopathy, surgical revascularization improves survival. Patients with mitral regurgitation experience significant functional improvement from mitral valve repair and replacement. In patients with aortic valve dysfunction, aortic valve replacement results in improved survival and functional status. Although surgical ventricular reconstruction is controversial, significant data exist suggesting that it is an effective therapy in a subset of patients with left ventricular dysfunction. Finally, passive restraint devices are effective at halting further ventricular dilation. Although cardiac surgery in patients with severe ventricular dysfunction can be complicated by significant morbidity and mortality, experienced centers have demonstrated acceptable outcomes in carefully selected patients.     

乙醇性胃粘膜损伤大鼠胃粘膜血液动力学变化及丹参提取物-F的作用

目的 :探讨不同浓度乙醇以及在事先给予丹参提取物 F ( DSE-F)和消炎痛的情况下大鼠胃粘膜血液动力学变化。方法 :用组织反射光谱分析仪 ( TS-2 0 0 )测定胃粘膜表层血液量 ( ΔEr)和 Hb氧饱和度 ( F)。结果 :( 1)胃粘膜损伤程度随乙醇浓度增高而加大 ;( 2 )低浓度乙醇引起胃粘膜充血 ,而高浓度则导致静脉淤血 ;( 3 )乙醇诱导的胃粘膜血液动力学变化因预先给予 DSE-F或消炎痛而减轻。结论 :( 1)乙醇性胃粘膜损伤的致病因素是高浓度乙醇所致的胃粘膜淤血缺氧 ;( 2 ) DSE-F对乙醇性胃粘膜损伤的保护作用在于减轻乙醇所致的胃粘膜血液动力学变化 ,后者可能与内源性前列腺素有关。     

Preoperative dobutamine stress echocardiography versus cardiac arteriography for risk assessment prior to renal transplantation

Abstract Because coronary artery disease is the leading cause of death in patients with end‐stage renal disease, we prospectively studied the prognostic value of dobutamine stress echocardiography (DSE) compared to coronary angiography (CA) as an evaluative tool. Thirty‐three patients at high risk for coronary artery disease were selected from a cohort of 133 renal transplant candidates and underwent both DSE and CA. In this study, the value of DSE was found to exist in its strong negative predictive value (92%). A negative DSE coupled with a negative clinical cardiac evaluation was found to practicably exclude the necessity for CA. DSE can thus serve as a non‐invasive, low cost screening test.