ACE/ACE2 Ratio and MMP-9 Activity as Potential Biomarkers in Tuberculous Pleural Effusions

Objective: Pleural effusion is common problem, but the rapid and reliable diagnosis for specific pathogenic effusions are lacking. This study aimed to identify the diagnosis based on clinical variables to differentiate pleural tuberculous exudates from other pleural effusions. We also investigated the role of renin-angiotensin system (RAS) and matrix metalloproteinase (MMPs) in the pathogenesis of pleural exudates.Experimental design: The major components in RAS and extracellular matrix metabolism, including angiotensin converting enzyme (ACE), ACE2, MMP-2 and MMP-9 activities, were measured and compared in the patients with transudative (n = 45) and exudative (n = 80) effusions. The exudative effusions were come from the patients with tuberculosis (n = 20), pneumonia (n = 32), and adenocarcinoma (n = 28).Results: Increased ACE and equivalent ACE2 activities, resulting in a significantly increased ACE/ACE2 ratio in exudates, were detected compared to these values in transudates. MMP-9 activity in exudates was significantly higher than that in transudates. The significant correlation between ACE and ACE2 activity that was found in transudates was not found in exudates. Advanced analyses showed significantly increased ACE and MMP-9 activities, and decreased ACE2 activity in tuberculous pleural effusions compared with those in pneumonia and adenocarcinoma effusions. The results indicate that increased ACE and MMP-9 activities found in the exudates were mainly contributed from a higher level of both enzyme activities in the tuberculous pleural effusions.Conclusion: Interplay between ACE and ACE2, essential functions in the RAS, and abnormal regulation of MMP-9 probably play a pivotal role in the development of exudative effusions. Moreover, the ACE/ACE2 ratio combined with MMP-9 activity in pleural fluid may be potential biomarkers for diagnosing tuberculous pleurisy.     

Extracellular matrix metabolism by chondrocytes 7. Evidence that L-glutamine is an essential amino acid for chondrocytes and other connective tissue cells

THe incorporation of [³H]glycine into acid-insoluble protein and of [³H]acetate into glysoaminoglycans by cultured chick chondrocytes was stimulated by the addition of L-glutamine to the incubation medium. The effect of exogenous L-glutamine on protein synthesis was studied further by examining changes in the sedimentation patterns on sucrose gardients of ribosomes isolated from chondrocytes incubated in presence and absence of L-glutamine. It was found that the absence of L-glutamine caused a disaggregation of poly-ribosomes that was reversed by the addition of this amino acid to the culture medium. No detectable glutamine synthetase activity could be measured in avian articular cartilage. These results indicate that L-glutamine is an essential amino acid for cartilage in that an extracellular supply of this amino acid is required for the maintenance of protein and glycosaminoglycan synthesis. A dependence on L-glutamine was also demonstrated for other avain connective tissues.     

Synthesis and transport of the organic matrix of the spicules in the gorgonian Leptogorgia virgulata (Lamarck) (Coelenterata: Gorgonacea)

Summary The sequence of the synthesis and transport of the organic matrix of spicules has been elucidated in the gorgonian Leptogorgia virgulata by use of ³H-aspartic acid as the tracer in electron-microscopic autoradiography. The entire process of matrix synthesis and transport takes approximately 2 h. It seems that the protein moiety of the organic matrix is synthesized in the RER prior to 5 min following the initial 10 min incubation in the tracer. At the 5 min chase the label is moving from the RER to the Golgi complexes where the carbohydrate moiety of the matrix is presumed to be synthesized. At the 5 to 15 min chases the label is transported out of the Golgi complexes via Golgi vesicles. This phase continues for 30 min. From 60 to 120 min the ³H-aspartic acid moves to the spicules. After 120 min the majority of the label has moved into the spicules. Silver grain counts over both multivesicular and electron-dense bodies remain at relatively low and constant levels over 4 h indicating that neither organelle is involved in the synthesis and transport of the organic matrix.Contribution No 512; Belle W. Baruch Institute for Marine Biology and Coastal Research, University of South Carolina, Columbia, South Carolina 29208, USA     

Trichoderma reesei sequences that bind to the nuclear matrix enhance transformation frequency

Three DNA fragments, trs1, 2 and 3, were isolated from the Trichoderma reesei genome on the basis of their ability to promote autonomous replication of plasmids in Saccharomyces cerevisiae. Each trs element bound specifically to the isolated T. reesei nuclear matrix in vitro, and two of them bound in vivo, indicating that they are matrix attachment regions (MARs). A similar sequence previously isolated from Aspergillus nidulans (ans1) was also shown to bind specifically to the T. reesei nuclear matrix in vitro. The T. reesei MARs are AT-rich sequences containing 70%, 86% and 73% A+T over 2.9, 0.8 and 3.7 kb, respectively for trs1, 2 and 3. They exhibited no significant sequence homology, but were shown to contain a number of sequence motifs that occur frequently in many MARs identified in other eukaryotes. However, these motifs occurred as frequently in the trs elements as in randomly generated sequences with the same A+T content. trs1 and 3 were shown to be present as single copies in the T. reesei genome. The presence of the trs elements in transforming plasmids enhanced the frequency of integrative transformation of T. reesei up to five fold over plasmids without a trs. No evidence was obtained to suggest that the trs elements promoted efficient replication of plasmids in T. reseei. A mechanism for the enhancement of transformation frequency by the trs elements is proposed. Received: 1 March 1997 / Accepted: 13 May 1997     

Glioma-Derived miRNA-Containing Extracellular Vesicles Induce Angiogenesis by Reprogramming Brain Endothelial Cells

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Three-dimensional perfused cell culture

Compelling evidence suggests the limitation and shortcomings of the current and well established cell culture method using multi-well plates, flasks and Petri dishes. These are particularly important when cell functions are sensitive to the local microenvironment, cell–cell and cell–extracellular matrix interactions. There is a clear need for advanced cell culture systems which mimic in vivo and more physiological conditions. This review summarises and analyses recent progress in three dimensional (3D) cell culture with perfusion as the next generation cell culture tools, while excluding engineered tissue culture where three dimensional scaffold has to be used for structural support and perfusion for overcoming mass transfer control. Apart from research activities in academic community, product development in industry is also included in this review.     

Comparing Stochastically Restricted Linear Estimators in a Regression Model

Conditions for superiority of the minimum dispersion estimator over another with respect to the covariance matrix are derived when the vector parameter of a regression model is subject to competing stochastic restrictions. The restrictions may also consist both of a deterministic part and a stochastic part.     

Variants of the Varimax Rotation Method

In the present paper we present an example proving that the Varimax rotation method commonly used in factor analysis (see H. F. KAISER, 1958) need not give a unique solution. We also show that changing the original algorithm more than one local maximum of the criterion “V” can be achieved. Hence the loadings of factors and practical interpretations of solutions are affected in this way.