Method of devising a muscle pump for assisted circulation

The authors have proposed a model of the blood pump from the skeletal automuscles of the body for carrying out aortal counterpulsation under experimental conditions. The pump is run by means of direct electric stimulation of the muscle. Have demonstrated that it is possible in principle to design a completely implanted small system of aortal counterpulsation.     

Diagnostic imaging of small amounts of pleural fluid: pleural effusion vs. physiologic pleural fluid

The aim of this article is to present an overview of our 10 years clinical research work and early clinical experience with small pleural effusions. Small amounts of pleural fluid are severely difficult to identify with imaging methods (chest x-rays and ultrasound). Nevertheless, it may be an important finding, sometimes leading to a definitive diagnosis of pleural carcinomatosis, infection or other pathologic condition. Chest x-rays were used for many years for the diagnosis of small pleural effusions. Lateral decubitus chest radiographs represented a gold standard for imaging of small amounts of plural fluid for more than 80 years. In the last two decades, ultrasonography of pleural space became a leading real-time method for demonstrating small pleural effusions. Furthermore, the advent of sonographic technology actually enables detection of physiologic pleural fluid in some otherwise healthy individuals. In conclusion, new definitions of the key terms in the field of diagnostic imaging of small amounts of pleural fluid seem to be justified. We suggest that the term pleural fluid should determine physiologic pleural space condition while the term pleural effusion should only be used in the cases of pleural involvement or pleural illness.     

Diagnostic accuracy of pleural fluid NT-pro-BNP for pleural effusions of cardiac origin: a systematic review and meta-analysis

Background

Proteolysis of matrix components, in particular elastin, is a major contributing factor to the development of lung diseases such as emphysema and chronic obstructive pulmonary disease (COPD). MMP-12 (macrophage elastase) is a protease known to be involved in the progression of lung disease. The relatively low abundance of MMP-12 has precluded the development of quantitative assays that can accurately measure MMP-12 protein levels and activity across cohorts of healthy and diseased individuals.

Methods

Commercial antibodies were screened for performance in sandwich ELISA and capture FRET activity assay formats. Precision, accuracy, sensitivity, dilution linearity, and spike recovery were evaluated using sputum samples.

Results

Total protein and capture FRET activity assays were developed that were sensitive enough to detect MMP-12 in 37 of 38 donor sputum samples. A comparison of results between the two assays shows that a majority of sputum MMP-12 is in the active form. No differences were seen between normal, asthmatic, and COPD donors.

Conclusion

Sensitive and quantitative assays for both MMP-12 activity and total protein in human induced sputum have been developed. These assays can be used to evaluate MMP-12 as a biomarker for lung disease, and to monitor efficacy of potential therapeutic compounds.     

Extreme environmental variation sharpens selection that drives the evolution of a mutualism

The importance of infrequent events for both adaptive evolution and the evolution of species interactions is largely unknown. We investigated how the infrequent production of large seed crops (masting) of a bird-dispersed tree (whitebark pine, Pinus albicaulis) influenced phenotypic selection exerted by its primary avian seed predator-disperser, the Clark's nutcracker (Nucifraga columbiana). Selection was not evident during common years of low seed abundance, whereas it was replicated among areas and favoured traits facilitating seed dispersal during infrequent years of high seed abundance. Since nutcrackers act mostly as seed predators during small seed crops but as seed dispersers during the largest seed crops, trees experienced strong selection from nutcrackers only during infrequent years when the interaction was most strongly mutualistic. Infrequent events can thus be essential to both adaptive evolution and the evolutionary dynamics of species interactions.     

Experimental evidence that extra-pair mating drives asymmetrical introgression of a sexual trait

Theory suggests that traits under positive selection may introgress asymmetrically across a hybrid zone, potentially driven by sexual selection. Two subspecies of the red-backed fairy-wren (Malurus melanocephalus) differ primarily in a sexual signal used in mate choice—red versus orange male back plumage colour—but phylogeographic analyses suggest asymmetrical introgression of red plumage into the genetic background of the orange subspecies. We hypothesized that this asymmetrical introgression may be facilitated by sexual selection if red males have a mating advantage over orange males. We tested this hypothesis with correlational data and a plumage manipulation experiment where we reddened the back plumage of a subset of orange males to mimic males of the red subspecies. There was no correlational evidence of a mating advantage to naturally redder males in this population. Experimentally reddened males sired a similar amount of within-pair young and lost paternity at the same rate as orange males, but they sired significantly more extra-pair young, leading to substantially higher total reproductive success. Thus, we conclude that sexual selection via extra-pair mating is a likely mechanism responsible for the asymmetrical introgression of plumage colour in this system, and is potentially driven by a sensory bias for the red plumage signal.     

The oxidative environment: a mediator of interspecies communication that drives symbiosis evolution

Symbiotic interactions are ubiquitous in nature and play a major role in driving the evolution of life. Interactions between partners are often mediated by shared signalling pathways, which strongly influence both partners'' biology and the evolution of the association in various environments. As an example of ‘common language’, the regulation of the oxidative environment plays an important role in driving the evolution of symbiotic associations. Such processes have been occurring for billions of years, including the increase in Earth''s atmospheric oxygen and the subsequent evolution of mitochondria. The effect of reactive oxygen species and reactive nitrogen species (RONS) has been characterized functionally, but the molecular dialogue between partners has not been integrated within a broader evolutionary context yet. Given the pleiotropic role of RONS in cell–cell communication, development and immunity, but also their associated physiological costs, we discuss here how their regulation can influence the establishment, the maintenance and the breakdown of various symbiotic associations. By synthesizing recent developments in redox biology, we aim to provide an interdisciplinary understanding of the influence of such mediators of interspecies communication on the evolution and stability of symbioses, which in turn can shape ecosystems and play a role in health and disease.     

Chaperone priming of pilus subunits facilitates a topological transition that drives fiber formation

Periplasmic chaperones direct the assembly of adhesive, multi-subunit pilus fibers that play critical roles in bacterial pathogenesis. Pilus assembly occurs via a donor strand exchange mechanism in which the N-terminal extension of one subunit replaces the chaperone G(1) strand that transiently occupies a groove in the neighboring subunit. Here, we show that the chaperone primes the subunit for assembly by holding the groove in an open, activated conformation. During donor strand exchange, the subunit undergoes a topological transition that triggers the closure of the groove and seals the N-terminal extension in place. It is this topological transition, made possible only by the priming action of the chaperone that drives subunit assembly into the fiber.     

Diagnostic considerations in prolymphocytes in pleural fluid: a case report

BACKGROUND: Prolymphocytes are nucleolated cells that are the defining features of the 2 chronic lymphoproliferative disorders, prolymphocytic leukemia (PLL) and chronic lymphocytic leukemia (CLL) with increased prolymphocytes. Prolymphocytes appear relatively unfamiliar in cytopathology practice, and, particularly when present in body fluids, may resemble blasts or adult T-cell leukemia/ lymphoma (ATLL) cells. CASE: A 32-year-old man, referred to us with a diagnosis of acute leukemia, presented with shortness of breath for 2 months and loss of appetite for 3 months. He had enlarged liver and spleen, 6 and 8 cm, respectively, below the costal margin and pleural effusion. The raised total leukocyte count chiefly comprised prolymphocytes that, especially in the pleural fluid, had prominent nucleoli and significant pleomorphism, raising the possibility of blasts or ATLL. CONCLUSION: Prolymphocytes in body fluids can be misinterpreted as blasts or even ATLL cells. Better awareness among cytopathologists about prolymphocytes and the disease states in which they occur, as well as insistence, in a clinical setting of leukemia, on interpreting the pleural fluid in relation to the clinical and laboratory findings, especially those of the peripheral blood and bone marrow, can prevent misdiagnosis. Equally importantly, immunophenotyping must be done in such situations.     

Morphostructural features of the pleural lymphatic circulation in the pig

The morphostructural features of the lymphatic circle of swine visceral pleura were investigated by means of vital dye injection in the pleural cavity. In the animals treated as mentioned previously it was possible to observe that in the visceral pleura the superficial lymphatic network had formed the very thick mesh, while the underlying pulmonary parenchyma was not interested. This behaviour lets us suppose that the drainage of the visceral pleura is mainly a direct one.     

Mycobacterium kansasii infection diagnosed by pleural fluid cytology: a case report

BACKGROUND: Identification of disseminated nontuberculous Mycobacterium infection is a challenge, especially when it occurs in patients without a known cause of immunosuppression. Acid-fast organisms in the pleural fluid are rare and easily missed, especially when they occur in patients without a clinical suspicion of infection. The classical cytologic picture of tuberculous pleural fluid with lymphocytosis and paucity of mesothelial cells is not seen. CASE: A 57-year-old man presented with chronic neutrophilia of unknown etiology together with chest pain and bilateral pleural effusions. Pleural fluid cytology revealed organisms seen in the cytoplasm of numerous macrophages and neutrophils, creating a "negative image" on Diff-Quik smears. Acid-fast stains demonstrated intracellular acid-fast bacilli consistent with mycobacteria. Microbiologic studies with DNA probe technology resulted in identification of the mycobacterial organism as Mycobacterium kansasii. CONCLUSION: Nontuberculous Mycobacterium should be included in the differential diagnosis in patients with inflammatory, exudative pleural effusions.     

A compact centrifugal blood pump for extracorporeal circulation: design and performance

A new compact centrifugal blood pump driven by a miniature DC servomotor has been designed for use for short-term extra corporeal and cardiac-assisted circulation. The impeller of the pump was connected directly to the motor by using a simple-gear coupling. The shaft for the impeller was sealed from blood by both a V-ring and a seal bearing. Either pulsatile or nonpusatile flow was produced by controlling the current supply to the motor. The pump characteristics and the degree of hemolysis were evaluated with regard to the configuration of the impeller with a 38-mm outer diameter in vitro tests; the impeller having the blade angles at the inlet of 20 deg and at the outlet of 50 deg was the most appropriate as a blood pump. The performance in an operation, hemolysis and thrombus formation in the pump were assessed by a left ventricular bypass experiment in dogs. It was suggested by this study that this prototype pump appears promising for use not only in animal experiments but also in clinical application.     

Model study of the effects of interactions between systemic and peripheral circulation on interstitial fluid balance

Interstitial fluid balance is severely altered in microgravity, but the mechanisms underlying the fluid shift from lower to upper body are still partially unclear. A lumped parameter model of the arterial tree with active and non linear modulation of peripheral resistances and capillary fluid exchange was adopted to simulate the response of microcirculation to pulsatility and edema. Results suggest that myogenic regulation not only impinges on arteriolar radius, but it also indirectly affects interstitial fluid balance. Non linear dynamics of blood pressure (BP) and flow in capillary beds are influenced by systemic pulsatility, hinting that local activity is involved in the response to peripheral edema as well.     

ADA2 isoform of adenosine deaminase from pleural fluid

Adenosine deaminase isoenzyme 2 (ADA2) was isolated from human pleural fluid for the first time. Molecular and kinetic properties were characterized. It was shown that the inhibitors of adenosine deaminase isoenzyme 1 (ADA1), adenosine, and erithro-9-(2-hydroxy-3-nonyl)adenine (EHNA) derivatives are poor inhibitors of ADA2. Comparison of the interaction of ADA2 and ADA1 with adenosine and its derivative, 1-deazaadenosine, indicates that the isoenzymes have similar active centers. The absence of ADA2 inhibition by EHNA is evidence of a difference of these active centers in a close environment. The possible role of Zn2+ ions and the participation of acidic amino acids Glu and Asp in adenosine deamination catalyzed by ADA2 were shown.