A new robotic platform for natural orifice surgery is described. The robot is designed to carry multiple tool tips in a single end-effector arm. Design and experimental validation are presented.
View Article and Find Full Text PDFExcessive narrowing of the airways due to airway smooth muscle (ASM) contraction is a major cause of asthma exacerbation. ASM is therefore a direct target for many drugs used in asthma therapy. The contractile mechanism of smooth muscle is not entirely clear.
View Article and Find Full Text PDFJ Appl Physiol (1985)
April 2011
The function of a complex system such as a smooth muscle cell is the result of the active interaction among molecules and molecular aggregates. Emergent macroscopic manifestations of these molecular interactions, such as the length-force relationship and its associated length adaptation, are well documented, but the molecular constituents and organization that give rise to these emergent muscle behaviors remain largely unknown. In this minireview, we describe emergent properties of airway smooth muscle that seem to have originated from inherent fragility of the cellular structures, which has been increasingly recognized as a unique and important smooth muscle attribute.
View Article and Find Full Text PDFCochrane Database Syst Rev
October 2010
Background: Corticosteroids remain one of the most popular medication choices for the induction of remission in ulcerative colitis and Crohn's disease. While corticosteroids may improve symptoms, they do not always result in mucosal healing and have significant adverse effects. Steroids which act topically, with less systemic side-effects may be more desirable.
View Article and Find Full Text PDFAirway smooth muscle (ASM) is able to generate maximal force under static conditions, and this isometric force can be maintained over a large length range due to length adaptation. The increased force at short muscle length could lead to excessive narrowing of the airways. Prolonged exposure of ASM to submaximal stimuli also increases the muscle's ability to generate force in a process called force adaptation.
View Article and Find Full Text PDFAm J Physiol Lung Cell Mol Physiol
November 2010
The wall of hollow organs of vertebrates is a unique structure able to generate active tension and maintain a nearly constant passive stiffness over a large volume range. These properties are predominantly attributable to the smooth muscle cells that line the organ wall. Although smooth muscle is known to possess plasticity (i.
View Article and Find Full Text PDFBackground: Post-operative lymph leak is a potentially serious complication which may contribute to fluid and electrolyte imbalance, malnutrition and an increase risk of sepsis and mortality. We aimed to study the use of TPN in the treatment of post-operative lymph leak.
Methods: Retrospective review of prospectively collected clinical database comprising patients with post-operative lymph leak treated with TPN collected over 1998-2006.
Phosphorylation of myosin by myosin light chain kinase (MLCK) is essential for smooth muscle contraction. In this study we show that caldesmon (CaD) is also phosphorylated in vitro by MLCK. The phosphorylation is calcium- and calmodulin (CaM)-dependent and requires a MLCK concentration close to that found in vivo.
View Article and Find Full Text PDFTidal breathing, and especially deep breathing, is known to antagonise bronchoconstriction caused by airway smooth muscle (ASM) contraction; however, this bronchoprotective effect of breathing is impaired in asthma. Force fluctuations applied to contracted ASM in vitro cause it to relengthen, force-fluctuation-induced relengthening (FFIR). Given that breathing generates similar force fluctuations in ASM, FFIR represents a likely mechanism by which breathing antagonises bronchoconstriction.
View Article and Find Full Text PDFCommonly occurring health hazards associated with the Hajj have been well described in the literature. However, there remain other serious but less well known health risks. We present here 2 cases of brucellosis contracted from drinking unpasteurised camel's milk during the Hajj.
View Article and Find Full Text PDFAm J Physiol Lung Cell Mol Physiol
March 2010
The amplitude of strain in airway smooth muscle (ASM) produced by oscillatory perturbations such as tidal breathing or deep inspiration (DI) influences the force loss in the muscle and is therefore a key determinant of the bronchoprotective and bronchodilatory effects of these breathing maneuvers. The stiffness of unstimulated ASM (passive stiffness) directly influences the amplitude of strain. The nature of the passive stiffness is, however, not clear.
View Article and Find Full Text PDFAirway smooth muscle (ASM) plays a vital role in the exaggerated airway narrowing seen in asthma. However, whether asthmatic ASM is mechanically different from nonasthmatic ASM is unclear. Much of our current understanding about ASM mechanics comes from measurements made in other species.
View Article and Find Full Text PDFSuccessful management of the patient with inflammatory bowel disease (IBD) involves not only the induction and maintenance of remission, but also the optimization of the benefit-to-risk equation to achieve the greatest gain in quality of life. These risks range from intolerance to prescribed medications to potentially life-threatening sequelae (eg, sepsis) of immune suppression. A proper awareness of risk on the part of the physician and education of the patient can lead to early detection and institution of an appropriate management plan, including risk management and, optimally, primary prevention (eg, prophylactic vaccination).
View Article and Find Full Text PDFBrucellosis, a zoonotic disease of worldwide distribution, is common in many developing countries as well as in countries of the Mediterranean basin. We report brucellosis in a 52-year-old man, who had a recent travel history to Saudi Arabia, and who presented with prolonged fever and deranged liver enzymes. In view of the rarity of brucellosis and its potential life-threatening complications, patients returning from an endemic country need to be questioned for possible Brucella exposure, to ensure that diagnostic tests and treatment are carried out in a timely fashion.
View Article and Find Full Text PDFBackground: We aimed to determine the optimal approach to assess disease activity (i.e., biological inflammation) in ulcerative colitis (UC) by comparing patients' and physicians' rating of the disease.
View Article and Find Full Text PDFBackground: Anti-tumour necrosis factor (TNF) therapy is now well established in the treatment of inflammatory bowel disease and the risk of opportunistic infection is recognized. However, specific considerations regarding screening, detection, prevention and treatment of chronic viral infections in the context of anti-TNF therapy in inflammatory bowel disease are not widely adopted in practice.
Aim: To provide a detailed and comprehensive review of the relevance of chronic viral infections in the context of anti-TNF therapy in inflammatory bowel disease.
Background And Aims: Antibodies to infliximab reduce serum infliximab with loss of clinical benefit, but undetectable trough serum concentrations of infliximab may occur without antibody formation. The relationship between trough serum infliximab and clinical outcomes was evaluated in acute ulcerative colitis.
Methods: In a cohort of 115 patients with ulcerative colitis treated with three-dose induction followed by scheduled maintenance infliximab, rates of clinical remission, colectomy, antibodies to infliximab and trough serum infliximab were determined.
Crohn's disease is characterized by recurrent transmural inflammation of the gastrointestinal tract, most commonly, the terminal ileum and the colon. Therapy is aimed at breaking the cycle of inflammation by inducing and maintaining remission. Current effective therapies include systemic corticosteroids, but this class of drugs is associated with a variety of adverse effects, which may lead to significant morbidity and even mortality.
View Article and Find Full Text PDFClin Gastroenterol Hepatol
October 2009
Objectives: We sought to evaluate whether two novel immunoglobulin A (IgA) cell wall polysaccharide antibodies, anti-laminarin (anti-L) and anti-chitin (anti-C), aid in the diagnosis and phenotype differentiation of Crohn's disease (CD) and ulcerative colitis (UC).
Methods: A cohort of 818 individuals with inflammatory bowel disease (IBD; 517 CD and 301 UC) from two IBD tertiary referral centers, with median ages of 33 and 39 years, respectively, and disease duration of 8.9 years, were phenotyped using the Montreal classification, and analyzed for seven anti-glycan antibodies (gASCA (anti-Saccharomyces cerevisiae) IgG, gASCA IgA, anti-chitobioside (GlcNAc(beta1,4)GlcNAc(beta)), anti-laminaribioside (Glc(beta1,3)Glb(beta)), anti-mannobioside (Man(alpha1,3)Man(alpha)), anti-L, and anti-C) and perinuclear atypical neutrophil cytoplasmic antibodies (pANCA).
Airway smooth muscle (ASM) in individuals with asthma is continuously stimulated by spasmogens released as part of chronic airway inflammation. This chronic submaximal stimulation of ASM produces "tone," which may or may not narrow airways sufficiently to induce respiratory symptoms. However, when coupled with a bronchoprovocative challenge with a nonspecific contractile agonist, this increased tone could contribute to the manifestation of airway hyperresponsiveness (AHR).
View Article and Find Full Text PDFStress and strain are omnipresent in the lung due to constant lung volume fluctuation associated with respiration, and they modulate the phenotype and function of all cells residing in the airways including the airway smooth muscle (ASM) cell. There is ample evidence that the ASM cell is very sensitive to its physical environment, and can alter its structure and/or function accordingly, resulting in either desired or undesired consequences. The forces that are either conferred to the ASM cell due to external stretching or generated inside the cell must be borne and transmitted inside the cytoskeleton (CSK).
View Article and Find Full Text PDFBreathing is known to functionally antagonize bronchoconstriction caused by airway muscle contraction. During breathing, tidal lung inflation generates force fluctuations that are transmitted to the contracted airway muscle. In vitro, experimental application of force fluctuations to contracted airway smooth muscle strips causes them to relengthen.
View Article and Find Full Text PDFAcute graft-versus-host disease following orthotopic liver transplantation is a rare but feared complication arising in 1% to 2% of cases with a dismal prognosis. It most often presents as fever, rash, and diarrhea with or without pancytopenia. Patients die from complications of marrow failure such as sepsis or bleeding.
View Article and Find Full Text PDFBackground: Corticosteroids have been shown to be effective for induction, but not maintenance of remission in Crohn's disease. However, significant concerns exist regarding their risk for adverse events, particularly when used for long treatment courses. Budesonide is a glucocorticoid with limited systemic bioavailability due to extensive first-pass hepatic metabolism.
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