Mechanism of NaCl transport-stimulated prostaglandin formation in MDCK cells

Recently we have found that stimulation of NaCl transport in high-resistance MDCK cells enhances their prostaglandin formation. In the present study, we investigated the mechanisms by which prostaglandin formation could be linked to the ion transport in these cells. We found that stimulation of transport caused a transient stimulation of prostaglandin formation lasting 5-10 min. The rise in prostaglandin formation was paralleled by a rise of free intracellular arachidonic acid. Analysis of membrane lipids revealed that the rise of free arachidonic acid was paralleled by a loss of arachidonic acid from polyphosphoinositides. We failed to obtain indications for the stimulation of calcium-dependent phospholipase A2. However, we did obtain evidence that the incorporation of arachidonic acid into phospholipids was diminished during stimulation of ion transport, indicating a decreased rate of reesterification. Despite the fact that there was no significant fall in total cellular ATP on stimulation of ion transport, we found a high and transient rise of lactate production of the cells on stimulation of the ion transport indicating an alteration of the ADP/ATP ratio. Moreover, prostaglandin formation and lactate formation were linearly correlated in this situation. When glucose utilization was inhibited by mannoheptulose, the rise in lactate formation was abolished, whereas that of PG formation was unaltered, indicating that lactate formation and prostaglandin formation were not causally linked on stimulation of ion transport. Our results suggest that an increase in the rate of sodium chloride transport by MDCK cells stimulates formation by an inhibition of reesterification of free arachidonic acid.(ABSTRACT TRUNCATED AT 250 WORDS

It is important that the process goes quickly, isn't it?” A qualitative multi-country study of colorectal or lung cancer patients’ narratives of the timeliness of diagnosis and quality of care

Purpose: The emphasis on early diagnosis to improve cancer survival has been a key factor in the development of cancer pathways across Europe. The aim of this analysis was to explore how the emphasis on early diagnosis and timely treatment is reflected in patient's accounts of care, from the first suspicion of colorectal or lung cancer to their treatment in Denmark, England and Sweden. Method: We recruited 155 patients in Denmark, England and Sweden who were within six months of being diagnosed with lung or colorectal cancer. Data were collected via semi-structured narrative interviews and analysed using a thematic approach. Results: Participants’ accounts of quality of care were closely related to how quickly (or not) diagnosis, treatment and/or healthcare processes went. Kinetic metaphors as a description of care (such as treadmill) could be interpreted positively as participants were willing to forgo some degree of control and accept disruption to their lives to ensure more timely care. Drawing on wider cultural expectations of the benefits of diagnosing and treating cancer quickly, some participants were concerned that the waiting times between interventions might allow time for the cancer to grow. Conclusions: Initiatives emphasising the timeliness of diagnosis and treatment are reflected in the ways some patients experience their care. However, these accounts were open to further contextualisation about what speed of healthcare processes meant for evaluating the quality of their care. Healthcare professionals could therefore be an important patient resource in providing reassurance and support about the timeliness of diagnosis or treatment

Absolute quantification of microbial proteomes at different states by directed mass spectrometry

The developed, directed mass spectrometry workflow allows to generate consistent and system-wide quantitative maps of microbial proteomes in a single analysis. Application to the human pathogen L. interrogans revealed mechanistic proteome changes over time involved in pathogenic progression and antibiotic defense, and new insights about the regulation of absolute protein abundances within operons

Swath-ms: a new data independent acquisition LC-MS methodology for quantitative complete proteome analysis

Comunicaciones a congreso

The Path to Preservation: Using Proteomics to Decipher the Fate of Diatom Proteins During Microbial Degradation

We drew upon recent advances in tandem mass spectrometry-based proteomic analyses in order to examine the proteins that remain after a diatom bloom enters the stationary phase, precipitates out of the photic zone, and is subjected to microbial degradation over a 23-d period within a controlled laboratory environment. Proteins were identified from tandem mass spectra searched against three different protein databases in order to track proteins from Thalassiosira pseudonana and any potential bacterial contributions. A rapid loss of diatom protein was observed over the incubation period; 75% of the proteins initially identified were not detected after 72 h of exposure to a microbial population. By the 23rd day, peptides identified with high confidence correlated with only four T. pseudonana proteins. Five factors may have influenced the preservation of diatom proteins: (1) protection within organelles or structures with multiple membranes, (2) the relative cellular abundance in the photosynthetic apparatus, (3) the number of transmembrane domains in the protein sequence, (4) the presence of glycan modification motifs, and (5) the capability of proteins or peptides to aggregate into supramolecules

Transient massive hyperlipidaemia in a type 2 diabetic subject

A 50-year-old man, in apparently good health, was referred to the Lipid Center of San Luigi Gonzaga Hospital, Orbassano (Turin, Italy), by his primary care physician (PCP) because clinical tests at the time of blood donation showed milky plasma with serious hypertriglyceridaemia (>5000 mg/dl) and hyperglycaemia (381 mg/dl), diagnostic for diabetes. It was not possible to perform further blood chemical analyses because hypertriglyceridaemia would have provided abnormal results. The patient entered the hospital to prevent acute pancreatitis, which is often associated with severe hypertriglyceridaemi

Bias-voltage dependence of the magneto-resistance in ballistic vacuum tunneling: Theory and application to planar Co(0001) junctions

Motivated by first-principles results for jellium and by surface-barrier shapes that are typically used in electron spectroscopies, the bias voltage in ballistic vacuum tunneling is treated in a heuristic manner. The presented approach leads in particular to a parameterization of the tunnel-barrier shape, while retaining a first-principles description of the electrodes. The proposed tunnel barriers are applied to Co(0001) planar tunnel junctions. Besides discussing main aspects of the present scheme, we focus in particular on the absence of the zero-bias anomaly in vacuum tunneling.Comment: 19 pages with 8 figure