A comparison of induction of anaesthesia using two different propofol preparations

Background: Investigators have reported inter-patient variability with regard to propofol dosage for induction of anesthesia, since early dose finding studies. With the arrival of generic formulations of propofol, questions have arisen regarding further variability in dose requirements. Various studies have confirmed that generic propofol preparations are pharmacokinetically and pharmacodynamically equivalent to Diprivan®. Nevertheless a number of practitioners are under the impression that certain generic propofol preparations require greater doses for induction of anaesthesia than does Diprivan®.Methods: 20 female patients of ASA status I-II, between the ages of 18-55 years, scheduled for routine surgery were randomly allocated to two groups to undergo induction of anaesthesia using two different propofol formulations; Diprivan® and Propofol 1% Fresenius®. Either preparation was administered using a target-controlled infusion of propofol (STEL-TCI) targeting the plasma (central) compartment at a concentration of 6 μg.ml-1, employing the pharmacokinetic parameters of Marsh et al. A processed EEG (bispectral index) was continuously recorded. Loss of consciousness (LOC) was regarded as the moment at which the patient could not keep her eyes open and was confirmed by the absence of an eyelash reflex. At this point propofol administration was discontinued and data were recorded for a further two minutes, before administering an appropriate opioid and/or nitrous oxide/volatile agent and/or muscle relaxant to maintain anaesthesia. Time to LOC after start of propofol administration, and the dose of propofol administered during induction were annotated. Results: There were no demographic differences between the groups. There were no differences between the groups with regard to the mean dose for LOC, time to LOC and to the mean BIS values obtained at the following stages: awake, at LOC, at 1 and 2 minutes after LOC as well as the lowest recorded value.Conclusions: Our results confirm that the two propofol formulations that we studied, are pharmacologically equivalent with regard to induction of anaesthesia. Other mechanisms can explain the variability in clinical response to bolus administration of propofol. The most important is the recirculatory or “front-end” kinetics of propofol in which cardiac output plays a major role, as well as the rate of drug administration. Emulsion degradation can also influence dose-response and in this regard it should be noted that the addition of foreign substances such as lignocaine, can result in rapid deterioration of the soyabean emulsion

Stimulation of hepatic regeneration after partial hepatectomy by infusion of a cytosol extract from regenerating dog liver

A cytosol liver extract was prepared from adult dog livers and from liver remnants that had been regenerating for one, two and three days after 72 per cent partial hepatectomy. Given intraportally, the most active of these cytosols did not stimulate proliferation in the livers of normal dogs. However, infused during a six hour period into the portal vein of test group dogs, the cytosol from 48 and, especially, 72 hour regenerating livers augmented the regeneration response ordinarily produced by 44 per cent partial hepatectomy. The effect was delayed. It became identifiable 48 hours after infusion and reached a peak at 72 hours. Neither augmentation nor significant inhibition of the normal regeneration response was produced by cytosol from normal liver and 24 hour regenerating liver or by a six hour infusion of insulin. The amplification effect of active cytosol was equivocal when the infusions were given intraperitoneally and was not demonstrable at all by the intravenous route. In these investigations, it is confirmed that there are growth control factors in regenerating liver but the nature or physiologic significance of the factor or factors has not been clarified

Cold treatment enhances low-temperature flight performance in false codling moth, Thaumatotibia leucotreta (Lepidoptera: Tortricidae)

1 In sterile insect technique programmes, temperatures experienced by insects during rearing and handling, along with cool temperatures after release, can negatively affect performance and activity levels. Phenotypic plasticity (trait modifications caused by prior stress exposure) can offset these effects but is poorly understood in many species and traits. 2 We investigated the effects of a cold treatment (2 ∘C for 16 h) on flight performance in adult false codling moth, Thaumatotibia leucotreta. Using diverse methods, flight performance was tested using flight assays in the laboratory and in the field under varying environmental conditions. 3 The flight performance of T. leucotreta in the laboratory was affected by cold treatment (relative to a 25 ∘C control group), test temperature and their interaction. Field recapture of released moths was significantly affected by the interaction between cold treatment and environmental conditions. 4 Field recapture counts depended on the ambient temperature upon release. For example, under warmer conditions (>17 ∘C), the recapture count of cold-treated moths was lower than that of the untreated control group, whereas the recapture count of cold-treated moths at cooler temperatures was significantly higher. 5 Our results suggest a temperature-dependent interaction between acute cold exposure and flight performance in adult T. leucotreta, which may be used to enhance the efficacy of the sterile insect technique under cooler environmental conditions

Generation Y and sparkling wines: a cross-cultural perspective

The aim of this study was to investigate and compare the engagement of Generation Y consumers with champagne and sparkling wine across five Anglophone countries. A qualitative approach was adopted using focus groups with young consumers, including images and wine tasting as projective stimuli. There were significant trans-cultural similarities between consumption behaviour (sparkling wine is a women’s drink, and a separate category from still wine, and that they will ‘grow into’ drinking it) but also noticeable differences (responses to images and colours varied substantially, as did attitudes to price and the particular status of champagne). Research into the behaviour of Generation Y as a cohort needs to take account of cultural as much as generational context. However, as a qualitative study the findings need further quantitative validation. Marketers cannot view Generation Y as a single group; even within countries marketing strategies may need to be refined depending on where a product is being sold

Building long-term marketing relationships: New perspectives on B2B financial services

The focus of this study was on the relevance of trust, satisfaction and commitment in maintaining a long-term relationship (intention to stay) with an exchange partner in a Business-to-Business (B2B) context in the financial services industry. The perceptions of 238 B2B clients of a leading South African provider of development capital were investigated. Since support could not be found for the existence of trust, commitment and satisfaction as distinct individual dimensions, this study provides empirical support for the amalgamation of some well-established individual dimensions into broader, more holistic dimensions as drivers of long-term relationship building. Contrary to expectations, B2B banking clients participating in this study appeared to regroup individual dimensions, in a heuristic fashion, to form new dimensions that influenced their attitude towards staying in a B2B relationship. As a result, building long-term marketing relationships seems to be a less complicated process than previously thought. Against this background, the primary contribution of the study is that it highlights the need for marketing practitioners to reconsider their current relationship-marketing strategies. As the findings of the study are inconsistent with conventional wisdom, they also challenge marketing academics to reconsider the theoretical foundations of relationship building in a B2B context

Diagnostic Pitfalls and Therapeutic Strategies in the Treatment of Pancreatic Duct Haemorrhage

Haemorrhage via the pancreatic duct, a rare cause of upper gastrointestinal bleeding (GIB), often poses a diagnostic dilemma. We analysed our experience with 10 patients (8 men, 2 women; mean age 44 years, range 34 – 62) treated during a 12 year period. All had a history of alcohol abuse and presented with major upper GIB requiring a median of 8 units (range 2 – 40) blood, transfusion. Nine had upper abdominal pain at the time of admission and nine had a history of pancreatitis. Upper gastroduodenal endoscopy (median 4; range 1 – 9), was diagnostic in only one. Side-viewing endoscopy showed bleeding from the pancreatic duct in 7 of 8 patients. Visceral aneurysms were demonstrated in 7 of 9 patients in whom coeliac angiography was carried out: (splenic artery 4, gastroduodenal artery 2, and pancreaticoduodenal artery 1). Two of 4 selective embolisations were successful. Six patients underwent distal pancreatectomy, 1 had gastroduodenal artery ligation and 1 died of coagulopathy following a total pancreatectomy. Pancreatic duct haemorrhage should be considered in patients with unexplained recurrent upper GIB, alcohol abuse and epigastric pain, particularly in those with established chronic pancreatitis. Selective angiography is essential for diagnosis and management. For bleeding sites in the head of the pancreas, embolisation should be attempted to avoid major resection. Distal pancreatectomy is preferred for splenic artery lesions

Development of an invasively monitored porcine model of acetaminophen-induced acute liver failure

Background: The development of effective therapies for acute liver failure (ALF) is limited by our knowledge of the pathophysiology of this condition, and the lack of suitable large animal models of acetaminophen toxicity. Our aim was to develop a reproducible invasively-monitored porcine model of acetaminophen-induced ALF. Method: 35kg pigs were maintained under general anaesthesia and invasively monitored. Control pigs received a saline infusion, whereas ALF pigs received acetaminophen intravenously for 12 hours to maintain blood concentrations between 200-300 mg/l. Animals surviving 28 hours were euthanased. Results: Cytochrome p450 levels in phenobarbital pre-treated animals were significantly higher than non pre-treated animals (300 vs 100 pmol/mg protein). Control pigs (n=4) survived 28-hour anaesthesia without incident. Of nine pigs that received acetaminophen, four survived 20 hours and two survived 28 hours. Injured animals developed hypotension (mean arterial pressure; 40.8+/-5.9 vs 59+/-2.0 mmHg), increased cardiac output (7.26+/-1.86 vs 3.30+/-0.40 l/min) and decreased systemic vascular resistance (8.48+/-2.75 vs 16.2+/-1.76 mPa/s/m3). Dyspnoea developed as liver injury progressed and the increased pulmonary vascular resistance (636+/-95 vs 301+/-26.9 mPa/s/m3) observed may reflect the development of respiratory distress syndrome. Liver damage was confirmed by deterioration in pH (7.23+/-0.05 vs 7.45+/-0.02) and prothrombin time (36+/-2 vs 8.9+/-0.3 seconds) compared with controls. Factor V and VII levels were reduced to 9.3 and 15.5% of starting values in injured animals. A marked increase in serum AST (471.5+/-210 vs 42+/-8.14) coincided with a marked reduction in serum albumin (11.5+/-1.71 vs 25+/-1 g/dL) in injured animals. Animals displayed evidence of renal impairment; mean creatinine levels 280.2+/-36.5 vs 131.6+/-9.33 mumol/l. Liver histology revealed evidence of severe centrilobular necrosis with coagulative necrosis. Marked renal tubular necrosis was also seen. Methaemoglobin levels did not rise >5%. Intracranial hypertension was not seen (ICP monitoring), but there was biochemical evidence of encephalopathy by the reduction of Fischer's ratio from 5.6 +/- 1.1 to 0.45 +/- 0.06. Conclusion: We have developed a reproducible large animal model of acetaminophen-induced liver failure, which allows in-depth investigation of the pathophysiological basis of this condition. Furthermore, this represents an important large animal model for testing artificial liver support systems

Framework, principles and recommendations for utilising participatory methodologies in the co-creation and evaluation of public health interventions

Background: Due to the chronic disease burden on society, there is a need for preventive public health interventions to stimulate society towards a healthier lifestyle. To deal with the complex variability between individual lifestyles and settings, collaborating with end-users to develop interventions tailored to their unique circumstances has been suggested as a potential way to improve effectiveness and adherence. Co-creation of public health interventions using participatory methodologies has shown promise but lacks a framework to make this process systematic. The aim of this paper was to identify and set key principles and recommendations for systematically applying participatory methodologies to co-create and evaluate public health interventions. Methods: These principles and recommendations were derived using an iterative reflection process, combining key learning from published literature in addition to critical reflection on three case studies conducted by research groups in three European institutions, all of whom have expertise in co-creating public health interventions using different participatory methodologies. Results: Key principles and recommendations for using participatory methodologies in public health intervention co-creation are presented for the stages of: Planning (framing the aim of the study and identifying the appropriate sampling strategy); Conducting (defining the procedure, in addition to manifesting ownership); Evaluating (the process and the effectiveness) and Reporting (providing guidelines to report the findings). Three scaling models are proposed to demonstrate how to scale locally developed interventions to a population level. Conclusions: These recommendations aim to facilitate public health intervention co-creation and evaluation utilising participatory methodologies by ensuring the process is systematic and reproducible