Spatial quantitation of drugs in tissues using liquid extraction surface analysis mass spectrometry imaging

Liquid extraction surface analysis mass spectrometry imaging (LESA-MSI) has been shown to be an effective tissue profiling and imaging technique, producing robust and reliable qualitative distribution images of an analyte or analytes in tissue sections. Here, we expand the use of LESA-MSI beyond qualitative analysis to a quantitative analytical technique by employing a mimetic tissue model previously shown to be applicable for MALDI-MSI quantitation. Liver homogenate was used to generate a viable and molecularly relevant control matrix for spiked drug standards which can be frozen, sectioned and subsequently analyzed for the generation of calibration curves to quantify unknown tissue section samples. The effects of extraction solvent composition, tissue thickness and solvent/tissue contact time were explored prior to any quantitative studies in order to optimize the LESA-MSI method across several different chemical entities. The use of a internal standard to normalize regional differences in ionization response across tissue sections was also investigated. Data are presented comparing quantitative results generated by LESA-MSI to LC-MS/MS. Subsequent analysis of adjacent tissue sections using DESI-MSI is also reported

The influence of blood on the efficacy of intraperitoneally applied phospholipids for prevention of adhesions

<p>Abstract</p> <p>Background</p> <p>The formation of adhesions following abdominal surgery is a well known problem. In previous studies we demonstrated the efficacy and safety of intraperitoneally applied phospholipids in order to prevent adhesion formation. This study evaluates the influence of blood on the efficacy of intraperitoneally applied phospholipids for prevention of adhesions.</p> <p>Methods</p> <p>In 40 Chinchilla rabbits adhesions were induced by median laparotomy, standardized abrasion of the visceral and parietal peritoneum in defined areas of the ventral abdominal wall and the caecum. The animals were randomly divided into four groups. They received either phospholipids 3.0% or normal saline (NaCl 0,9%) (5 ml/kg body weight). In 50% of the rabbits we simulated intraperitoneal bleeding by administration of blood (1,5 ml/kg body weight). The other half served as control group. Ten days following the operation the animals were sacrificed and adhesion formation was assessed by computer aided planimetry and histopathologic examination.</p> <p>Results</p> <p>The median adhesion surface area in the NaCl-group (n = 9) amounted to 68,72 mm², in the NaCl+Blood-group (n = 10) 147,68 mm². In the Phospholipid (PhL)-group (n = 9) the median adhesion surface area measured 9,35 mm², in the PhL+Blood-group (n = 9) 11,95 mm². The phospholipid groups had a significantly smaller adhesion surface area (p < 0.05).</p> <p>Conclusion</p> <p>Again these results confirm the efficacy of phospholipids in the prevention of adhesions in comparison to NaCl (p = 0,04). We also demonstrated the adhesion preventing effect of phospholipids in the presence of intraperitoneal blood.</p

Reactive oxygen species initiate luminal but not basal cell death in cultured human mammary alveolar structures: a potential regulator of involution

Post-lactational involution of the mammary gland is initiated within days of weaning. Clearing of cells occurs by apoptosis of the milk-secreting luminal cells in the alveoli and through stromal tissue remodeling to return the gland almost completely to its pre-pregnant state. The pathways that specifically target involution of the luminal cells in the alveoli but not the basal and ductal cells are poorly understood. In this study we show in cultured human mammary alveolar structures that the involution process is initiated by fresh media withdrawal, and is characterized by cellular oxidative stress, expression of activated macrophage marker CD68 and finally complete clearing of the luminal but not basal epithelial layer. This process can be simulated by ectopic addition of reactive oxygen species (ROS) in cultures without media withdrawal. Cells isolated from post-involution alveoli were enriched for the CD49f+ mammary stem cell (MaSC) phenotype and were able to reproduce a complete alveolar structure in subcultures without any significant loss in viability. We propose that the ROS produced by accumulated milk breakdown post-weaning may be the mechanism underlying the selective involution of secretory alveolar luminal cells, and that our culture model represents an useful means to investigate this and other mechanisms further

Results of the MAJORANA DEMONSTRATOR's Search for Double-Beta Decay of 76Ge to Excited States of 76Se

The MAJORANA DEMONSTRATOR is searching for double-beta decay of 76Ge to excited states (E.S.) in 76Se using a modular array of high purity Germanium detectors. 76Ge can decay into three E.S.s of 76Se. The E.S. decays have a clear event signature consisting of a ββ-decay with the prompt emission of one or two γ-rays, resulting in with high probability in a multi-site event. The granularity of the DEMONSTRATOR detector array enables powerful discrimination of this event signature from backgrounds. Using 21.3 kg-y of isotopic exposure, the DEMONSTRATOR has set world leading limits for each E.S. decay, with 90% CL lower half-life limits in the range of (0.56 2.1) ⋅ 1024 y. In particular, for the 2v transition to the first 0+ E.S. of 76Se, a lower half-life limit of 0.68 ⋅ 1024 at 90% CL was achieved

ADC Nonlinearity Correction for the Majorana Demonstrator

Imperfections in analog-to-digital conversion (ADC) cannot be ignored when signal digitization requirements demand both wide dynamic range and high resolution, as is the case for the Majorana Demonstrator 76Ge neutrinoless double-beta decay search. Enabling the experiment's high-resolution spectral analysis and efficient pulse shape discrimination required careful measurement and correction of ADC nonlinearities. A simple measurement protocol was developed that did not require sophisticated equipment or lengthy data-taking campaigns. A slope-dependent hysteresis was observed and characterized. A correction applied to digitized waveforms prior to signal processing reduced the differential and integral nonlinearities by an order of magnitude, eliminating these as dominant contributions to the systematic energy uncertainty at the double-beta decay Q value

Why it takes an 'ontological shock' to prompt increases in small firm resilience : sensemaking, emotions and flood risk

This article uses a sensemaking approach to understand small firms’ responses to the threat of external shocks. By analysing semi-structured interviews with owners of flooded small firms, we investigate how owners process flood experiences and explore why such experiences do not consistently lead to the resilient adaptation of premises. We, conclude that some of the explanation for low levels of adaptation relates to a desire to defend existing sensemaking structures and associated identities. Sensemaking structures are only revised if these structures are not critical to business identity, or if a flood constitutes an ‘ontological shock’ and renders untenable existing assumptions regarding long-term business continuity. This article has implications for adaptation to the growing risk of flooding, climate change and external shocks. Future research analysing external shocks would benefit from using a sensemaking approach and survey studies should include measurements of ‘ontological’ impact as well as material and financial damage. In addition, those designing information campaigns should take account of small firms’ resistance to information that threatens their existing sensemaking structures and social identities

An Algorithm Informed by the Parathyroid Hormone Level Reduces Hypocalcemic Complications of Thyroidectomy

Ó The Author(s) 2010. This article is published with open access at Springerlink.com Background Measurement of the parathyroid hormone (PTH) level following total thyroidectomy (TTx) may allow prediction of postoperative hypocalcemia. We present an algorithmic method of managing hypocalcemia preemptively, based on the PTH level 1 h after operation. Materials and methods We examined 423 consecutive patients undergoing TTx at a single institution. A subset of patients were managed using an algorithm involving routine postoperative oral calcium administration and the early addition of oral calcitriol in patients with a low 1-h postoperative PTH level. Algorithm patients were compared to a concurrent, conventionally managed group. Outcomes measured included serum calcium levels, symptoms of hypocalcemia, postoperative complications, and receipt of intravenous (IV) calcium. Results The algorithm was applied in 135 patients, and 288 patients were managed conventionally. Critically low calcium levels (total calcium \7.5 mg/dl [1.88 mmol/l] or ionized calcium \0.94 mmol/l) were less common in algorithm patients (10.6 % vs. 25.3%; p \ 0.005). Much of this difference was attributable to the protective impact of the algorithm on patients undergoing TTx for cancer, 30% of whom developed critically low calcium levels when managed conventionally. Among patients requiring IV calcium, algorithm patients received fewer doses (1.29 vs

Association of herd BRSV and BHV-1 seroprevalence with respiratory disease and reproductive performance in adult dairy cattle

<p>Abstract</p> <p>Background</p> <p>The aim of this study was to detect the associations between bovine herpesvirus 1 (BHV-1) status of a herd and respiratory disease (BRD) occurrence and reproductive performance in pregnant heifers and cows. The association between management-related factors and higher BRD occurrence was also estimated.</p> <p>Methods</p> <p>Serum samples, collected from cows and youngstock from 103 dairy cattle herds, were analyzed for antibodies against BHV-1, bovine respiratory syncytial virus (BRSV), bovine viral diarrhoea virus (BVDV), and <it>Mycoplasma bovis</it>. A questionnaire was used to collect data concerning herd management factors and reproductive performance, as well as the occurrence of clinical signs of respiratory disease in the last two years, as evaluated by the veterinarian or farm manager. Multiple correspondence analysis (MCA) and logistic regression analysis were performed to identify and quantify the risk factors.</p> <p>Results</p> <p>A low to moderate prevalence (1-49%) of BRSV antibodies among youngstock was associated with a high occurrence of respiratory disease (OR = 6.2, p = 0.010) in cows and in-calf heifers. Employees of the farm may participate in the spread of such disease. Larger herd size, loose-housing of cows, housing youngstock separately from cows until pregnancy, and purchasing new animals were factors possibly related to a high occurrence of respiratory disease symptoms in pregnant heifers and cows. The highest risk of abortions (> 1.3%) and increased insemination index (number of inseminations per pregnancy) (> 1.9) occurred in herds with a moderate prevalence of BHV-1 antibodies (1-49%) in cows.</p> <p>Conclusions</p> <p>BHV-1 was not associated with acute respiratory disease in adult dairy cattle, however was significantly related to reproductive performance. BRSV possesses the main role in respiratory disease complex in adult dairy cattle.</p