An in vitro study comparing a peripherally inserted central catheter to a conventional central venous catheter: no difference in static and dynamic pressure transmission

<p>Abstract</p> <p>Background</p> <p>Early goal directed therapy improves survival in patients with septic shock. Central venous pressure (CVP) monitoring is essential to guide adequate resuscitation. Use of peripherally inserted central catheters (PICC) is increasing, but little data exists comparing a PICC to a conventional CVP catheter. We studied the accuracy of a novel PICC to transmit static and dynamic pressures <it>in vitro</it>.</p> <p>Methods</p> <p>We designed a device to generate controlled pressures via a column of water allowing simultaneous measurements from a PICC and a standard triple lumen catheter. Digital transducers were used to obtain all pressure readings. Measurements of static pressures over a physiologic range were recorded using 5Fr and 6Fr dual lumen PICCs. Additionally, random repetitive pressure pulses were applied to the column of water to simulate physiologic intravascular pressure variations. The resultant PICC and control waveforms were recorded simultaneously.</p> <p>Results</p> <p>Six-hundred thirty measurements were made using the 5 Fr and 6 Fr PICCs. The average bias determined by Bland-Altman plot was 0.043 mmHg for 5 Fr PICC and 0.023 mmHg for 6 Fr PICC with a difference range of 1.0 to -1.0. The correlation coefficient for both catheters was 1.0 (p-value < 0.001). Dynamic pressure waveforms plotted simultaneously between PICC and control revealed equal peaks and troughs.</p> <p>Conclusion</p> <p><it>In vitro</it>, no static or dynamic pressure differences were found between the PICC and a conventional CVP catheter. Clinical studies are required to assess whether the novel PICC has bedside equivalence to conventional catheters when measuring central venous pressures.</p

A comparison of nicotine dose estimates in smokers between filter analysis, salivary cotinine, and urinary excretion of nicotine metabolites

RATIONALE: Nicotine uptake during smoking was estimated by either analyzing the metabolites of nicotine in various body fluids or by analyzing filters from smoked cigarettes. However, no comparison of the filter analysis method with body fluid analysis methods has been published. OBJECTIVES: Correlate nicotine uptake estimates between filter analysis, salivary cotinine, and urinary excretion of selected nicotine metabolites to determine the suitability of these methods in estimating nicotine absorption in smokers of filtered cigarettes. MATERIALS AND METHODS: A 5-day clinical study was conducted with 74 smokers who smoked 1–19 mg Federal Trade Commission tar cigarettes, using their own brands ad libitum. Filters were analyzed to estimate the daily mouth exposure of nicotine. Twenty-four-hour urine samples were collected and analyzed for nicotine, cotinine, and 3′-hydroxycotinine plus their glucuronide conjugates. Saliva samples were collected daily for cotinine analysis. RESULTS: Each method correlated significantly (p < 0.01) with the other two. The best correlation was between the mouth exposure of nicotine, as estimated by filter analysis, and urinary nicotine plus metabolites. Multiple regression analysis implies that saliva cotinine and urinary output are dependent on nicotine mouth exposure for multiple days. Creatinine normalization of the urinary metabolites degrades the correlation with mouth exposure. CONCLUSIONS: The filter analysis method was shown to correlate with more traditional methods of estimating nicotine uptake. However, because filter analysis is less complicated and intrusive, subjects can collect samples easily and unsupervised. This should enable improvements in study compliance and future study designs

Phylodynamics of HIV-1 Subtype B among the Men-Having-Sex-with-Men (MSM) Population in Hong Kong

The men-having-sex-with-men (MSM) population has become one of the major risk groups for HIV-1 infection in the Asia Pacific countries. Hong Kong is located in the centre of Asia and the transmission history of HIV-1 subtype B transmission among MSM remained unclear. The aim of this study was to investigate the transmission dynamics of HIV-1 subtype B virus in the Hong Kong MSM population. Samples of 125 HIV-1 subtype B infected MSM patients were recruited in this study. Through this study, the subtype B epidemic in the Hong Kong MSM population was identified spreading mainly among local Chinese who caught infection locally. On the other hand, HIV-1 subtype B infected Caucasian MSM caught infection mainly outside Hong Kong. The Bayesian phylogenetic analysis also indicated that 3 separate subtype B epidemics with divergence dates in the 1990s had occurred. The first and latest epidemics were comparatively small-scaled; spreading among the local Chinese MSM while sauna-visiting was found to be the major sex partner sourcing reservoir for the first subtype B epidemic. However, the second epidemic was spread in a large-scale among local Chinese MSM with a number of them having sourced their sex partners through the internet. The epidemic virus was estimated to have a divergence date in 1987 and the infected population in Hong Kong had a logistic growth throughout the past 20 years. Our study elucidated the evolutionary and demographic history of HIV-1 subtype B virus in Hong Kong MSM population. The understanding of transmission and growth model of the subtype B epidemic provides more information on the HIV-1 transmission among MSM population in other Asia Pacific high-income countries

The YARHG Domain: An Extracellular Domain in Search of a Function

We have identified a new bacterial protein domain that we hypothesise binds to peptidoglycan. This domain is called the YARHG domain after the most highly conserved sequence-segment. The domain is found in the extracellular space and is likely to be composed of four alpha-helices. The domain is found associated with protein kinase domains, suggesting it is associated with signalling in some bacteria. The domain is also found associated with three different families of peptidases. The large number of different domains that are found associated with YARHG suggests that it is a useful functional module that nature has recombined multiple times

Generation of Variants in Listeria monocytogenes Continuous-Flow Biofilms Is Dependent on Radical-Induced DNA Damage and RecA-Mediated Repair

The food-borne pathogen Listeria monocytogenes is a Gram-positive microaerophilic facultative anaerobic rod and the causative agent of the devastating disease listeriosis. L. monocytogenes is able to form biofilms in the food processing environment. Since biofilms are generally hard to eradicate, they can function as a source for food contamination. In several occasions biofilms have been identified as a source for genetic variability, which potentially can result in adaptation of strains to food processing or clinical conditions. However, nothing is known about mutagenesis in L. monocytogenes biofilms and the possible mechanisms involved. In this study, we showed that the generation of genetic variants was specifically induced in continuous-flow biofilms of L. monocytogenes, but not in static biofilms. Using specific dyes and radical inhibitors, we showed that the formation of superoxide and hydroxyl radicals was induced in continuous-flow biofilms, which was accompanied with in an increase in DNA damage. Promoter reporter studies showed that recA, which is an important component in DNA repair and the activator of the SOS response, is activated in continuous-flow biofilms and that activation was dependent on radical-induced DNA damage. Furthermore, continuous-flow biofilm experiments using an in-frame recA deletion mutant verified that RecA is required for induced generation of genetic variants. Therefore, we can conclude that generation of genetic variants in L. monocytogenes continuous-flow biofilms results from radical-induced DNA damage and RecA-mediated mutagenic repair of the damaged DNA

Correlation between p38 mitogen-activated protein kinase and human telomerase reverse transcriptase in sarcomas

<p>Abstract</p> <p>Background</p> <p>One of the major components of telomerase is the human telomerase reverse transcriptase (hTERT) as the catalytic protein. hTERT mRNA expression are reported to be associated with prognosis and tumor progression in several sarcomas. However, there is no clear understanding of the mechanisms of hTERT in human sarcomas. Recent studies have suggested that signals transmitted through p38 mitogen-activated protein kinase (MAPK) can increase or decrease hTERT transcription in human cells. The purpose of this study was to analyse the correlation between p38 MAPK and hTERT in sarcoma samples.</p> <p>Methods</p> <p>We investigated 36 soft tissue malignant fibrous histiocytomas (MFH), 24 liposarcomas (LS) and 9 bone MFH samples for hTERT and p38 MAPK expression. Quantitative detection of hTERT and p38 MAPK was performed by RT-PCR.</p> <p>Results</p> <p>There was a significant positive correlation between the values of hTERT and p38 MAPK in all samples (r = 0.445, p = 0.0001), soft tissue MFH (r = 0.352, p = 0.0352), LS (r = 0.704, p = 0.0001) and bone MFH samples (r = 0.802, p = 0.0093). Patients who had a higher than average expression of p38 MAPK had a significantly worse prognosis than other patients (p = 0.0036).</p> <p>Conclusions</p> <p>p38 MAPK may play a role in up-regulation of hTERT, and therefore, p38 MAPK may be a useful marker in the assessment of hTERT and patients' prognosis in sarcomas.</p

Neurodegenerative influence of oxidative stress in the retina of a murine model of diabetes

Aims/hypothesis: Diabetic retinopathy is a progressive neuro-degenerative disease, but the underlying mechanism is still obscure. Here, we focused on oxidative stress in the retina, and analysed its influence on retinal neurodegeneration, using an antioxidant, lutein. Methods: C57BL/6 mice with streptozotocin-induced diabetes were constantly fed either a lutein-supplemented diet or a control diet from the onset of diabetes, and their metabolic data were recorded. In 1-month-diabetic mice, reactive oxygen species (ROS) in the retina were measured using dihydroethidium and visual function was evaluated by electroretinograms. Levels of activated extracellular signal-regulated kinase (ERK), synaptophysin and brain-derived neurotrophic factor (BDNF) were also measured by immunoblotting in the retina of 1-month-diabetic mice. In the retinal sections of 4-month-diabetic mice, histological changes, cleaved caspase-3 and TUNEL staining were analysed. Results: Lutein did not affect the metabolic status of the diabetic mice, but it prevented ROS generation in the retina and the visual impairment induced by diabetes. ERK activation, the subsequent synaptophysin reduction, and the BDNF depletion in the diabetic retina were all prevented by lutein. Later, in 4-month-diabetic mice, a decrease in the thickness of the inner plexiform and nuclear layers, and ganglion cell number, together with increase in cleaved caspase-3- and TUNEL-positive cells, were avoided in the retina of lutein-fed mice. Conclusions/interpretation: The results indicated that local oxidative stress that has a neurodegenerative influence in the diabetic retina is prevented by constant intake of a lutein-supplemented diet. The antioxidant, lutein may be a potential therapeutic approach to protect visual function in diabetes

A Customer Perspective on Product Eliminations: How the Removal of Products Affects Customers and Business Relationships

Regardless of the apparent need for product eliminations, many managers hesitate to act as they fear deleterious effects on customer satisfaction and loyalty. Other managers do carry out product eliminations, but often fail to consider the consequences for customers and business relationships. Given the relevance and problems of product eliminations, research on this topic in general and on the consequences for customers and business relationships in particular is surprisingly scarce. Therefore, this empirical study explores how and to what extent the elimination of a product negatively affects customers and business relationships. Results indicate that eliminating a product may result in severe economic and psychological costs to customers, thereby seriously decreasing customer satisfaction and loyalty. This paper also shows that these costs are not exogenous in nature. Instead, depending on the characteristics of the eliminated product these costs are found to be more or less strongly driven by a company’s behavior when implementing the elimination at the customer interface