Multistage Process (multistage + process)

Distribution by Scientific Domains


Selected Abstracts


Monitoring the care of lung cancer patients: linking audit and care pathways

JOURNAL OF EVALUATION IN CLINICAL PRACTICE, Issue 1 2001
E. Kaltenthaler BSc
Abstract Clinical audit plays an important role in monitoring the provision of care for patients whatever their condition. Care pathways define the steps and expected course of events in the care of patients with a specific clinical problem over a set time scale. This paper describes a study undertaken in a multisite cancer unit to develop a tool for monitoring the progress of lung cancer patients through a care pathway and auditing key standards within the pathway. Important issues associated with the development of this tool are highlighted. The process of developing this tool involved the following steps: a review of the literature dealing with the management of lung cancer patients; interviews with key personnel in primary, secondary, tertiary and palliative care; development of a paper-based series of forms representing key steps in the patient's care pathway; 3-month trial of the paper-based tool; analysis of completion rates and interviews with form users to evaluate effectiveness; and recommendations for creating an electronic record using the experience and lessons learned from the paper version. The paper forms developed through this multistage process were found to be acceptable to users and have the potential to provide accurate information at key points for audit throughout the patient's time within the health-care system for their lung cancer condition. The flexibility of this methodology allows it to be adapted readily to a variety of clinical situations and conditions. [source]


Role of intestinal metaplasia subtyping in the risk of gastric cancer in Korea

JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 1 2009
Kyung P Kang
Abstract Background and Aim:, Gastric cancer is believed to develop by a multistage process. Intestinal metaplasia (IM) is regarded as a premalignant condition; it is classified into subtypes I, II and III. The aim of this study was to evaluate whether the subtypes of IM were associated with progression to gastric cancer. Methods:, The study cohort consisted of 861 subjects, categorized as controls, gastric ulcers, dysplasia and cancer. The IM was scored histologically using the Sydney classification for the antrum and the body of the stomach. The biopsies were stained with high iron diamine and alcian blue (pH 2.5) (HID-AB2.5), and the IM was subtyped as I, II or III. Results:, The proportion of IM subtypes I, II and III were 14.5%, 47.2% and 38.3% in the antrum, and 28.1%, 57.8% and 14.1% in the body of the stomach, respectively. These distributions did not show significant differences depending on disease or Helicobacter pylori positivity. In cases that were H. pylori -positive, the prevalence of IM subtype II in the cancer and dysplasia groups was higher than in the control group in the body of the stomach (P < 0.05). The proportion of IM subtype III in the antrum increased in proportion with age (P = 0.036). Conclusions:, IM subtyping was not found to play a major role in the prediction of gastric cancer development in Korea. IM subtype III was associated with aging, and IM subtype II appeared to be related to gastric carcinogenesis in the presence of H. pylori infection. [source]


Enantioseparation via EIC-OSN: Process design and improvement of enantiomers resolvability and separation performance

AICHE JOURNAL, Issue 4 2010
Issara Sereewatthanawut
Abstract This article presents a mathematical model to assess and optimize the separation performance of an enantioselective inclusion complexation-organic solvent nanofiltration process. Enantiomer solubilities, feed concentrations, solvent compositions, permeate solvent volumes, and numbers of nanofiltrations were identified as key factors for process efficiency. The model was first tested by comparing calculated and experimental results for a nonoptimized process, and then, calculations were carried out to select the best operating conditions. An important finding was that the optimal configuration varied with the objective function selected, e.g., resolvability versus yield, with a boundary on product optical purity. The model also suggested that the process efficiency could benefit from diafiltration of the distomer and from the use of higher feed concentrations. However, the latter strategy would result in higher losses of eutomer. To address this drawback, a multistage process was evaluated using the verified process model. © 2009 American Institute of Chemical Engineers AIChE J, 2010 [source]


Single-nucleotide polymorphisms and mRNA expression for melatonin synthesis rate-limiting enzyme in recurrent depressive disorder

JOURNAL OF PINEAL RESEARCH, Issue 4 2010
Piotr Ga, ecki
Abstract:, Depressive disorder (DD) is characterised by disturbances in blood melatonin concentration. It is well known that melatonin is involved in the control of circadian rhythms, sleep included. The use of melatonin and its analogues has been found to be effective in depression therapy. Melatonin synthesis is a multistage process, where the last stage is catalysed by acetylserotonin methyltransferase (ASMT), the reported rate-limiting melatonin synthesis enzyme. Taking into account the significance of genetic factors in depression development, the gene for ASMT may become an interesting focus for studies in patients with recurrent DD. The goal of the study was to evaluate two single-nucleotide polymorphisms (SNPs) (rs4446909; rs5989681) of the ASMT gene, as well as mRNA expression for ASMT in recurrent DD-affected patients. We genotyped two polymorphisms in a group of 181 recurrent DD patients and in 149 control subjects. The study was performed using the polymerase chain reaction/restriction fragment length polymorphism method. The distribution of genotypes in both studied SNPs in the ASMT gene differed significantly between DD and healthy subjects. The presence of AA genotype of rs4446909 polymorphism and of GG genotype of rs5989681 polymorphism was associated with lower risk for having recurrent DD. In turn, patients with depression were characterised by reduced mRNA expression for ASMT. In addition, ASMT transcript level in both recurrent DD patients and in healthy subjects depended significantly on genotype distributions in both polymorphisms. In conclusion, our results suggest the ASMT gene as a susceptibility gene for recurrent DD. [source]


Vascular Development and Differentiation During Human Liver Organogenesis

THE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 6 2008
Sophie Collardeau-Frachon
Abstract The vascular architecture of the human liver is established at the end of a complex embryological history. The hepatic primordium emerges at the 4th week and is in contact with two major venous systems of the fetal circulation: the vitelline veins and the umbilical veins. The fetal architecture of the afferent venous circulation of the liver is acquired between the 4th and the 6th week. At the end of this process, the portal vein is formed from several distinct segments of the vitelline veins; the portal sinus, deriving from the subhepatic intervitelline anastomosis, connects the umbilical vein, which is the predominant vessel of the fetal liver, to the portal system; the ductus venosus connects the portal sinus to the vena cava inferior. At birth, the umbilical vein and the ductus venosus collapse; the portal vein becomes the only afferent vein of the liver. The efferent venous vessels of the liver derive from the vitelline veins and are formed between the 4th and the 6th week. The hepatic artery forms at the 8th week; intrahepatic arterial branches progressively extend from the central to the peripheral areas of the liver between the 10th and the 15th week. Hepatic sinusoids appear very early, as soon as hepatic cords invade the septum transversum at the 4th week. They then progressively acquire their distinctive structural and functional characters, through a multistage process. Vascular development and differentiation during liver organogenesis is, therefore, a unique process; many of the cellular and molecular mechanisms involved remain poorly understood. Anat Rec, 291:614,627, 2008. © 2008 Wiley-Liss, Inc. [source]


Chromophore Interaction in Xanthorhodopsin,Retinal Dependence of Salinixanthin Binding,

PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 4 2008
Eleonora S. Imasheva
Xanthorhodopsin is a light-driven proton pump in the extremely halophilic bacterium Salinibacter ruber. Its unique feature is that besides retinal it has a carotenoid, salinixanthin, with a light harvesting function. Tight and specific binding of the carotenoid antenna is controlled by binding of the retinal. Addition of all- trans retinal to xanthorhodopsin bleached with hydroxylamine restores not only the retinal chromophore absorption band, but causes sharpening of the salinixanthin bands reflecting its rigid binding by the protein. In this report we examine the correlation of the changes in the two chromophores during bleaching and reconstitution with native all- trans retinal, artificial retinal analogs and retinol. Bleaching and reconstitution both appear to be multistage processes. The carotenoid absorption changes during bleaching occurred not only upon hydrolysis of the Schiff base but continued while the retinal was leaving its binding site. In the case of reconstitution, the 13-desmethyl analog formed the protonated Schiff base slower than retinal, and provided the opportunity to observe changes in carotenoid binding at various stages. The characteristic sharpening of the carotenoid bands, indicative of its reduced conformational heterogeneity in the binding site, occurs when the retinal occupies the binding site but the covalent bond to Lys-240 via a Schiff base is not yet formed. This is confirmed by the results for retinol reconstitution, where the Schiff base does not form but the carotenoid exhibits its characteristic spectral change from the binding. [source]