Pulmonary Pseudallescheria boydii infection with cutaneous zygomycosis after near drowning

Pseudallescheria boydii is a ubiquitously occurring fungus. While rarely causing opportunistic infection in humans, it is the most common cause of fungal pneumonia in cases of near drowning, and is associated with high mortality. P. boydii typically causes cutaneous mycetomas but may invade the lungs or brain. P. boydii infections are difficult to treat due to amphotericin B resistance and frequent need for surgical resection. Zygomycetous infections, often referred to as "mucormycoses," usually occur in immunocompromised hosts, trauma or burn victims. Like P. boydii, these organisms are found on decaying vegetation and in soil. Zygomycetous infections generally require debridement and prolonged amphotericin B. We report a case of P. boydii pneumonia with a simultaneous brain lesion and cutaneous mucormycosis in a near drowning patient. The pneumonia responded to treatment with voriconazole and the brain lesion resolved without surgery. The cutaneous mucormycosis responded to surgery and amphotericin B. This is the first documented case of simultaneous invasive P. boydii and cutaneous mucormycosis successfully treated with dual systemic antifungal therapy and resection.     

Plasma exchange as rescue therapy in multiple organ failure including acute renal failure

OBJECTIVE: To describe the outcome of using a rescue therapy including plasma exchange given to patients with a progressive acute disseminated intravascular coagulation and multiple organ dysfunction syndrome. STUDY DESIGN: Retrospective study. SETTING: University and county hospital. PATIENTS: Included were 76 consecutive patients (41 men and 35 women) treated with plasma exchange as rescue therapy besides optimal conventional therapy during a progressive course of disseminated intravascular coagulation and multiple organ dysfunction syndrome, including acute renal failure. Of the 76 patients, 66% needed dialysis. The distribution was hemodialysis in 76%, continuous arteriovenous hemofiltration in 36%, continuous venovenous hemodialysis in 12%, and peritoneal dialysis in 24%. The median organ-failure score was 5 (range, 1-6). Seventy-two percent required mechanical ventilation; septic shock was present in 88%. The median septic shock score was 4 (range, 2-4). Nine patients had another reason than sepsis for the multiple organ dysfunction syndrome. INTERVENTION: Plasma exchange (centrifugation technique) was performed until disseminated intravascular coagulation was reversed (median, two times; range, 1-14). Besides antibiotics and fluid administration, most patients received heparin or low molecular weight heparin (77%), steroids (87%), and inotropes (88%). More than one vasoactive drug was used in 57% of the patients. MEASUREMENTS AND MAIN RESULTS: Eighty-two percent of the patients survived and could leave the hospital. The previously observed survival rates by others for this category of patients would be <20%, and thus, the outcome in this study is significantly better. CONCLUSION: Plasma exchange using plasma as replacement may, in addition to conventional intensive care, help to reverse severe progressive disseminated intravascular coagulation and multiple organ dysfunction syndrome and improve survival.     

Oscillations in cytoplasmic free calcium concentration in human pancreatic islets from subjects with normal and impaired glucose tolerance

Summary Plasma insulin levels in healthy subjects oscillate and non-insulin-dependent diabetic patients display an irregular pattern of such oscillations. Since an increase in cytoplasmic free Ca²⁺ concentration ([Ca²⁺]_i) in the pancreatic beta cell is the major stimulus for insulin release, this study was undertaken to investigate the dynamics of electrical activity, [Ca²⁺]_i-changes and insulin release, in stimulated islets from subjects of varying glucose tolerance. In four patients it was possible to investigate more than one of these three parameters. Stimulation of pancreatic islets with glucose and tolbutamide sometimes resulted in the appearance of oscillations in [Ca²⁺]_i, lasting 2–3 min. Such oscillations were observed even in some islets from patients with impaired glucose tolerance. In one islet from a diabetic patient there was no response to glucose, whereas that islet displayed [Ca²⁺]_i-oscillations in response to tolbutamide, suggesting that sulphonylurea treatment can mimic the complex pattern of glucose-induced [Ca²⁺]_i-oscillations. We also, for the first time, made patch-clamp recordings of membrane currents in beta-cells in situ in the islet. Stimulation with glucose and tolbutamide resulted in depolarization and appearance of action potentials. The islet preparations responded to stimulation with a number of different secretagogues with release of insulin. The present study shows that human islets can respond to stimulation with glucose and sulphonylurea with oscillations in [Ca²⁺]_i, which is the signal probably underlying the oscillations in plasma insulin levels observed in healthy subjects. Interestingly, even subjects with impaired glucose tolerance had islets that responded with oscillations in [Ca²⁺]_i upon glucose stimulation, although it is not known to what extent the response of these islets was representative of most islets in these patients.Abbreviations [Ca²⁺]_i Cytoplasmic free Ca²⁺ - NIDDM non-insulin-dependent diabetes mellitus - DMSO dimethylsulphoxide - PC pancreatic cancer     

Computerized image analysis of lung expansion patterns in surfactant treated immature newborn rabbits.

This study evaluates the alveolar stereological profile of immature rabbit lungs after treatment with various surfactant preparations, deliberately modified to represent different rates of film adsorption, minimum surface tension and compressibility. Surfactant was isolated from porcine or bovine lungs, and some of these preparations were enriched with dipalmitoylphosphatidylcholine and other synthetic lipids. Alveolar stereological parameters were evaluated in histological lung sections by computerized interactive image analysis. Surfactant treatment enhanced lung expansion, with a significant correlation coefficient between dynamic compliance and alveolar volume density in all groups of animals. Surfactant treatment also significantly increased alveolar image area. Enrichment of surfactant with synthetic lipids did not improve stereological parameters, but caused a significant increase in the coefficient of variation for alveolar perimeter and image area, suggesting more heterogeneous expansion pattern. Experimental evaluation of exogenous surfactants in immature newborn animals should include assessment of alveolar stereological parameters to detect deviations from the uniform expansion pattern seen after treatment with an optimal surfactant substitute.     

Nucleation of protein fibrillation by nanoparticles

Nanoparticles present enormous surface areas and are found to enhance the rate of protein fibrillation by decreasing the lag time for nucleation. Protein fibrillation is involved in many human diseases, including Alzheimer's, Creutzfeld-Jacob disease, and dialysis-related amyloidosis. Fibril formation occurs by nucleation-dependent kinetics, wherein formation of a critical nucleus is the key rate-determining step, after which fibrillation proceeds rapidly. We show that nanoparticles (copolymer particles, cerium oxide particles, quantum dots, and carbon nanotubes) enhance the probability of appearance of a critical nucleus for nucleation of protein fibrils from human beta(2)-microglobulin. The observed shorter lag (nucleation) phase depends on the amount and nature of particle surface. There is an exchange of protein between solution and nanoparticle surface, and beta(2)-microglobulin forms multiple layers on the particle surface, providing a locally increased protein concentration promoting oligomer formation. This and the shortened lag phase suggest a mechanism involving surface-assisted nucleation that may increase the risk for toxic cluster and amyloid formation. It also opens the door to new routes for the controlled self-assembly of proteins and peptides into novel nanomaterials.     

Understanding the nanoparticle-protein corona using methods to quantify exchange rates and affinities of proteins for nanoparticles

Due to their small size, nanoparticles have distinct properties compared with the bulk form of the same materials. These properties are rapidly revolutionizing many areas of medicine and technology. Despite the remarkable speed of development of nanoscience, relatively little is known about the interaction of nanoscale objects with living systems. In a biological fluid, proteins associate with nanoparticles, and the amount and presentation of the proteins on the surface of the particles leads to an in vivo response. Proteins compete for the nanoparticle "surface," leading to a protein "corona" that largely defines the biological identity of the particle. Thus, knowledge of rates, affinities, and stoichiometries of protein association with, and dissociation from, nanoparticles is important for understanding the nature of the particle surface seen by the functional machinery of cells. Here we develop approaches to study these parameters and apply them to plasma and simple model systems, albumin and fibrinogen. A series of copolymer nanoparticles are used with variation of size and composition (hydrophobicity). We show that isothermal titration calorimetry is suitable for studying the affinity and stoichiometry of protein binding to nanoparticles. We determine the rates of protein association and dissociation using surface plasmon resonance technology with nanoparticles that are thiol-linked to gold, and through size exclusion chromatography of protein-nanoparticle mixtures. This method is less perturbing than centrifugation, and is developed into a systematic methodology to isolate nanoparticle-associated proteins. The kinetic and equilibrium binding properties depend on protein identity as well as particle surface characteristics and size.     

Fibronectin 1 is a potential biomarker for radioresistance in head and neck squamous cell carcinoma

Radiotherapy remains the backbone of head and neck cancer therapy but response is sometimes impeded by tumor radioresistance. Identifying predictive biomarkers of radiotherapy response is a crucial step towards personalized therapy. The aim of this study was to explore gene expression data in search of biomarkers predictive of the response to radiotherapy in head and neck squamous cell carcinoma (HNSCC). Microarray analysis was performed on five cell lines with various intrinsic radiosensitivity, selected from a panel of 29 HNSCC cell lines. The bioinformatics approach included Gene Ontology (GO) enrichment profiling and Ingenuity Pathway Analysis (IPA). The GO-analysis detected 16 deregulated categories from which development, receptor activity, and extracellular region represented the largest groups. Fourteen hub genes (CEBPA, CEBPB, CTNNB1, FN1, MYC, MYCN, PLAU, SDC4, SERPINE1, SP1, TAF4B, THBS1, TP53 and VLDLR) were identified from the IPA network analysis. The hub genes in the highest ranked network, (FN1, SERPINE1, THBS1 and VLDLR) were further subjected to qPCR analysis in the complete panel of 29 cell lines. Of these genes, high FN1 expression associated to high intrinsic radiosensitivity (p=0.047). In conclusion, gene ontologies and hub genes of importance for intrinsic radiosensitivity were defined. The overall results suggest that FN1 should be explored as a potential novel biomarker for radioresistance.     

Psychosocial and dental factors in the maintenance of severe dental fear

The aim was to study the relationship between psychosocial factors and dental status in adult subjects with severe dental fear (DF). A consecutive sample of 148 adults (mean age 36.1 yrs, range 21-69 yrs) referred for dental fear treatment was investigated using an intake questionnaire on dental attendance and history, psychometric questionnaires on dental fear, general anxiety and depression and a radiographic examination. The subjects had a mean DFMT (Decayed, Filled, Missed Teeth) score of 18.6 (SD = 5.6). A deterioration in dental status defined as the presence of root remnants was present in 57% of the subjects and was related to the negative consequences of dental fear, general anxiety and depression. Most subjects (84%) reported clinical levels of general anxiety and 46% reported clinical levels of depression. In conclusion, subjects with severe DF often suffer from psychosocial consequences and distress.This is even more marked if their dental status has deteriorated.The findings support a biopsychosocial vicious circle understanding of the maintenance of DF.