Self-sampling is appropriate for detection of Staphylococcus aureus: a validation study

<p>Abstract</p> <p>Background</p> <p>Studies frequently use nasal swabs to determine <it>Staphylococcus aureus</it> carriage. Self-sampling would be extremely useful in an outhospital research situation, but has not been studied in a healthy population. We studied the similarity of self-samples and investigator-samples in nares and pharynxes of healthy study subjects (hospital staff) in the Netherlands.</p> <p>Methods</p> <p>One hundred and five nursing personnel members were sampled 4 times in random order after viewing an instruction paper: 1) nasal self-sample, 2) pharyngeal self-sample, 3) nasal investigator-sample, and 4) pharyngeal investigator-sample.</p> <p>Results</p> <p>For nasal samples, agreement is 93% with a kappa coefficient of 0.85 (95% CI 0.74-0.96), indicating excellent agreement, for pharyngeal samples agreement is 83% and the kappa coefficient is 0.60 (95% CI 0.43-0.76), indicating good agreement. In both sampling sites self-samples even detected more <it>S. aureus</it> than investigator-samples.</p> <p>Conclusions</p> <p>This means that self-samples are appropriate for detection of <it>Staphylococcus aureus</it> and methicillin-resistant <it>Staphylococcus aureus</it>.</p

A 50% Reduction of Excitability but Not of Intercellular Coupling Affects Conduction Velocity Restitution and Activation Delay in the Mouse Heart

Computer simulations suggest that intercellular coupling is more robust than membrane excitability with regard to changes in and safety of conduction. Clinical studies indicate that SCN5A (excitability) and/or Connexin43 (Cx43, intercellular coupling) expression in heart disease is reduced by approximately 50%. In this retrospective study we assessed the effect of reduced membrane excitability or intercellular coupling on conduction in mouse models of reduced excitability or intercellular coupling. Epicardial activation mapping of LV and RV was performed on Langendorff-perfused mouse hearts having the following: 1) Reduced excitability: Scn5a haploinsufficient mice; and 2) reduced intercellular coupling: Cx43(CreER(T)/fl) mice, uninduced (50% Cx43) or induced (10% Cx43) with Tamoxifen. Wild type (WT) littermates were used as control. Conduction velocity (CV) restitution and activation delay were determined longitudinal and transversal to fiber direction during S(1)S(1) pacing and S(1)S(2) premature stimulation until the effective refractory period. In both animal models, CV restitution and activation delay in LV were not changed compared to WT. In contrast, CV restitution decreased and activation delay increased in RV during conduction longitudinal but not transverse to fiber direction in Scn5a heterozygous animals compared to WT. In contrast, a 50% reduction of intercellular coupling did not affect either CV restitution or activation delay. A decrease of 90% Cx43, however, resulted in decreased CV restitution and increased activation delay in RV, but not LV. Reducing excitability but not intercellular coupling by 50% affects CV restitution and activation delay in RV, indicating a higher safety factor for intercellular coupling than excitability in R

The bio in the ink: cartilage regeneration with bioprintable hydrogels and articular cartilage-derived progenitor cells

Cell-laden hydrogels are the primary building blocks for bioprinting, and, also termed bioinks, are the foundations for creating structures that can potentially recapitulate the architecture of articular cartilage. To be functional, hydrogel constructs need to unlock the regenerative capacity of encapsulated cells. The recent identification of multipotent articular cartilage-resident chondroprogenitor cells (ACPCs), which share important traits with adult stem cells, represents a new opportunity for cartilage regeneration. However, little is known about the suitability of ACPCs for tissue engineering, especially in combination with biomaterials. This study aimed to investigate the potential of ACPCs in hydrogels for cartilage regeneration and biofabrication, and to evaluate their ability for zone-specific matrix production. Gelatin methacryloyl (gelMA)-based hydrogels were used to culture ACPCs, bone marrow mesenchymal stromal cells (MSCs) and chondrocytes, and as bioinks for printing. Our data shows ACPCs outperformed chondrocytes in terms of neo-cartilage production and unlike MSCs, ACPCs had the lowest gene expression levels of hypertrophy marker collagen type X, and the highest expression of PRG4, a key factor in joint lubrication. Co-cultures of the cell types in multi-compartment hydrogels allowed generating constructs with a layered distribution of collagens and glycosaminoglycans. By combining ACPC- and MSC-laden bioinks, a bioprinted model of articular cartilage was generated, consisting of defined superficial and deep regions, each with distinct cellular and extracellular matrix composition. Taken together, these results provide important information for the use of ACPC-laden hydrogels in regenerative medicine, and pave the way to the biofabrication of 3D constructs with multiple cell types for cartilage regeneration or in vitro tissue models

Persistence of Livestock Associated MRSA CC398 in Humans Is Dependent on Intensity of Animal Contact

INTRODUCTION: The presence of Livestock Associated MRSA (LA-MRSA) in humans is associated with intensity of animal contact. It is unknown whether the presence of LA-MRSA is a result of carriage or retention of MRSA-contaminated dust. We conducted a longitudinal study among 155 veal farmers in which repeated nasal and throat swabs were taken for MRSA detection. Periods with and without animal exposure were covered. METHODS: Randomly, 51 veal calf farms were visited from June-December 2008. Participants were asked to fill in questionnaires (n = 155) to identify potential risk factors for MRSA colonisation. Nasal and throat swabs were repeatedly taken from each participant for approximately 2 months. Swabs were analysed for MRSA and MSSA by selective bacteriological culturing. Spa-types of the isolates were identified and a ST398 specific PCR was performed. Data were analyzed using generalized estimation equations (GEE) to allow for correlated observations within individuals. RESULTS: Mean MRSA prevalence was 38% in farmers and 16% in family members. Presence of MRSA in farmers was strongly related to duration of animal contact and was strongly reduced in periods with absence of animal contact (-58%). Family members, especially children, were more often carriers when the farmer was a carrier (OR = 2,

Гибридная интегральная схема для обработки звукового сигнала

Разработана гибридная интегральная схема с номинальным напряжением питания 1,4 В, током потребления 0,7 мА и габаритными размерами 8x4x3 мм для обработки звукового сигнала в автономной аппаратуре.Розроблена гібридна інтегральна схема з номінальною напругою живлення 1,4 В, струмом споживання 0,7 мА і габаритними розмірами 8x4x3 мм забезпечує багатофункціональну обробку звуковою сигналу в аналоговій мікроелектронній апаратурі. Наведено її конструкторсько-технологічні та електричні параметри.Developed hybrid integrated circuit with rated supply voltage of 1,4 V, current consumption 0,7 mA and overall dimensions 8x4x3 mm provides soft processing of the audio signal in analog microelectronic equipment. Given its design, technological and electrical parameters