Plasmin enhances cell surface tissue factor activity in mesothelial and endothelial cells

BACKGROUND

Mesothelial cells that line the thoracic cavity play an important role in maintaining the local balance between procoagulant and fibrinolytic activity, a role akin to the endothelial cells in blood vessels. The mechanism(s) responsible for increased tissue factor (TF) expression in mesothelial cells in response to injury are at present unclear.

OBJECTIVE

To investigate whether plasmin or thrombin, two major proteases that may be generated on the pleural surface upon injury, induce TF expression in human pleural mesothelial cells (HMC) and elucidate the underlying mechanism(s).

METHODS

Confluent monolayers of HMC and human umbilical vein endothelial cells (HUVEC) were exposed to plasmin or thrombin for varying time periods and TF expression was analyzed by measuring its activity in a factor Xa generation assay, TF antigen levels by immunoblot analysis and TF mRNA by Northern blot analysis.

RESULTS

Both plasmin and thrombin treatments increased cell surface TF activity in HMC by 3- to 4-fold. In contrast to thrombin, plasmin-induced TF activity is not dependent on the de novo synthesis of TF. In HUVEC, plasmin had a minimal effect on unperturbed HUVEC whereas it markedly increased TF activity of activated HUVEC. Plasmin treatment neither affected anionic phospholipid levels at the cell surface nor released protein disulfide isomerase, an oxidoreductase protein that was newly described to play a role in TF activation. Plasmin cleaved cell-associated TFPI.

CONCLUSION

Thrombin up-regulates TF activity in HMC through the transcriptional activation of TF whereas plasmin increases TF activity by inactivating the cell-associated TFPI by a limited proteolysis.

Evidence of short-range screening in shock-compressed aluminum plasma

We have investigated the angular variation in elastic x-ray scattering from a dense, laser-shock-compressed aluminum foil. A comparison of the experiment with simulations using an embedded atom potential in a molecular dynamics simulation shows a significantly better agreement than simulations based on an unscreened one-component plasma model. These data illustrate, experimentally, the importance of screening for the dense plasma static structure factor.

Optimization of magneto-optical Kerr setup: analyzing experimental assemblies using Jones matrix formalism

We present a comparative study on an experimental and theoretical optimization of magneto-optical Kerr setups based on photoelastic modulation and phase sensitive detector methodology. The first and second harmonics, I omega,2 omega, of the reflected light intensity are measured for a CoO/Co magnetic reference film. The magnetic field dependence of the optical off-diagonal Fresnel reflection coefficients rps and rsp follows the sample magnetization. Different Kerr setups provide various dependencies of I omega,2 omega on the reflection coefficients and, hence, on the Kerr ellipticity epsilon K and rotation theta K. Jones matrix formalism has been used to analyze the impact of a systematic variation of relative analyzer and polarizer orientations with respect to each other and with respect to the retardation axis of the modulator involved in longitudinal Kerr setups for incoming s-polarized light. We find one particular setup which maximizes I(omega) as well as I2 omega and maximizes the signal-to-noise ratio. Inefficient setups are characterized by I omega,2 omega intensities involving large nonmagnetic contributions of rp and rs.

Compton scatter profiles for warm dense matter

In this paper, we discuss the possibility of using x-ray Compton scattering as a probe of the outer electronic structure of ions immersed in warm dense matter. It is proposed that the x-ray free-electron lasers currently under construction will provide an ideal tool for this, with the main pulse being used to create a uniform well-defined sample and the third harmonic providing a clean monochromatic probe. We model the plasma photon scatter spectrum by combining self-consistent finite-temperature electronic structure calculations with molecular dynamics simulations of the ion-ion structure factor. In particular, we present bound-free Compton profiles that are more accurate that those obtained using form factor or impulse approximations.

Optimization of physical and nutritional parameters for hyaluronidase production by <i> Streptococcus mitis</i>

The effect of some physical and nutritional parameters were studied for the optimum production of extracellular enzyme hyaluronidase employing Streptococcus mitis MTCC*2695 by submerged fermentation. The effects of initial pH, incubation temperature and time, inoculum level and age of inoculum were studied. The maximum enzymatic activity was obtained with an initial pH 5.8, incubation temperature 37°, incubation time for 48 h and inoculum level 6% with inoculum age 24 h. The effect of different carbon and nitrogen sources and antibiotics were studied. The results indicated that sucrose and ammonium chloride showed the highest enzymatic activity among various carbon and nitrogen sources. Antibiotic clarithromycin showed strong inhibitory effect on hyaluronidase production.

Reactive oxygen species induced by shear stress mediate cell death in Bacillus subtilis

Exposure of Bacillus subtilis to a shear rate of 1,482/s leads to a rapid loss of cell viability after 10 h of growth. Biochemical and molecular evidences provided below strongly suggest that cell death under high shear results from an apoptosis-like process similar to that described in eukaryotes, with activation of a caspase-3-like protease (C(3)LP) followed by DNA fragmentation. Shear stress leads to an increase in specific intracellular reactive oxygen species (siROS), possibly through activation of NADH oxidase (NOX). The formation of siROS precedes the activation of C(3)LP and DNA fragmentation, thus establishing siROS as the molecular link between shear stress and apoptosis-like cell death. A model is proposed in which NOX is viewed as being strategically placed on the plasma membrane of B. subtilis that senses and converts a mechanical force arising from shear stress into a chemical signal leading to activation of C(3)LP, DNA fragmentation, and thus, apoptosis-like cell death.

Characterization of a Novel Polymeric Scaffold for Potential Application in Tendon/Ligament Tissue Engineering

Unlike braided fabrics, knitted scaffolds have been proven to favor deposition of collagenous connective tissue matrix, which is crucial for tendon/ligament reconstruction. But cell seeding of such scaffolds often requires a gel system, which is unstable in a dynamic situation, especially in the knee joint. This study developed a novel, biodegradable nano-microfibrous polymer scaffold by electrospinning PLGA nanofibers onto a knitted PLGA scaffold in order to provide a large biomimetic surface for cell attachment. Porcine bone marrow stromal cells were seeded onto either the novel scaffolds by pipetting a cell suspension (Group I) or the knitted PLGA scaffolds by immobilizing in fibrin gel (Group II). Cell attachment at 36 hours, cell proliferation and extracellular matrix synthesis at 1 week, and mechanical properties over 2 weeks were investigated. Cell attachment was comparable and cell proliferation was faster in Group I. Moreover, cellular function was more actively exhibited in Group I, as evident by the higher expression of collagen I, decorin, and biglycan genes. Thus, this novel scaffold, facilitating cell seeding and promoting cell proliferation, function, and differentiation, could be applied with promise in tissue engineering of tendon/ligament.

Macro-level and genetic-level responses of Bacillus subtilis to shear stress

Responses of bacterial (Bacillus subtilis) cells under different shear levels, from both the macro and genetic viewpoints, have been presented. The responses were studied using a novel, couette flow bioreactor (CFB), in which the entire cultivation can be performed under defined shear conditions. Oxygen supply, the normal limiting factor for entire cultivations under defined shear conditions, has been achieved by passing air through a poly(tetrafluoroethylene) (PTFE) membrane fixed on the inner cylinder of the CFB. More importantly, analyses of the oxygen transfer capabilities as well as the shear rates show that in this CFB, the effects of defined shear can be studied without interference from the effects of oxygen supply. Further, the shake flask can be used as a proper control for studying the shear effects, mainly because the shear rate in the shake flask under normal shaker operating conditions of 190 rpm has been estimated to be a negligible 0.028 s(-1) compared to a value of 445 s(-1) at the lowest rpm employed in the CFB. At the macro level the cell size decreased by almost 50% at 1482 s(-1) compared to that at 0.028 s(-1), the growth rate increased by 245%, and the maximum cell concentration increased by 190% when the shear rate was increased from 0.028 to 1482 s(-1). The specific intracellular catalase level increased by 335% and protease by 87% at 1482 s(-1) as compared to the control cultures at a shear rate 0.028 s(-1). In addition, the specific intracellular reactive oxygen species level (siROS) at the highest shear rate was 9.3-fold compared to the control conditions. At the genetic level we have established the involvement of the transcription factor, sigma(B), in the bacterial responses to shear stress, which was unknown in the literature thus far; the sigma(B) expression correlated inversely with the siROS. Further, through experiments with ROS quenchers, we showed that ROS regulated sigma(B) expression under shear.

Intracellular reactive oxygen species mediate suppression of sporulation inBacillus subtilis under shear stress

Sporulation is an important cellular response to stress that is also significant from a bioreactor operation viewpoint. While sporulating organisms are known to show an enhanced sporulation response under several stress situations, the sporulation response to shear stress has not been investigated thus far. Such a study could be of interest since shear stress, to a greater or lesser degree, is always present in bioreactor operation. In this article, we investigate the sporulation extents of the Gram-positive bacteria Bacillus subtilis at various defined shear levels. We show that, contrary to expectations, shear inhibits sporulation. We found an inverse correlation between the shear rate-dependent specific intracellular reactive oxygen species level (siROS), and the sporulation extent. A 10-fold increase in siROS resulted in about 17-fold decrease in sporulation extent. The involvement of reactive oxygen species (ROS) in sporulation was unknown thus far. Further, through experiments that specifically increased and reduced intracellular ROS (iROS), we established that siROS is responsible for the inhibition of sporulation under shear stress. In addition, we found that shear induced siROS regulated the expression levels of the general stress proteins Ctc and sigma(B). Based on the above, we hypothesize that siROS may regulate suppression of sporulation under high shear by altering sigma(B) and Ctc expression levels, and a model for the same is presented.

Neonatal aortic arch thrombosis masquerading as coarctation of the aorta

We report two neonates with thrombosis of the aortic arch and isthmus diagnosed by echocardiography. Neonatal transient protein C deficiency was present in one patient and the other patient had severe perinatal asphyxia. Both patients presented with markedly reduced left ventricular function and severe aortic obstruction. In one infant, the thrombus was successfully removed surgically, and the second infant died due to serious complications of perinatal asphyxia.

Induced reactive oxygen species improve enzyme production from Aspergillus niger cultivation

Intracellular reactive oxygen species (iROS) induction by HOCl was used as a novel strategy to improve enzyme productivities in Aspergillus niger growing in a bioreactor. With induced iROS, the specific intracellular activities of alpha-amylase, protease, catalase, and glucose oxidase were increased by about 170%, 250%, 320%, and 260%, respectively. The optimum specific iROS level for achieving maximum cell concentration and enzyme production was about 15 mmol g cell-1. The type of iROS inducing the enzyme production was identified to be a derivative of the superoxide radical.

Coding DNA sequences: statistical distributions

The base distributions in coding DNA sequences (CDS) are investigated. We explore the scaling properties of the 4-dimensional directed random walk and compare them with that for the DNA sequences. Inference from these observation are, however, contradicted by alternate analysis using factorial moments. To resolve this conflict we look directly at the nucleotide base distributions. In all the cases the base distributions change from gaussian to non-gaussian as the scale size is increased. The CDS, therefore, have nucleotide distributions different from the random.

Graft copolymerization of acrylonitrile and ethyl methacrylate comonomers on cellulose using ceric ions

The graft copolymerization of acrylonitrile and ethyl methacrylate from their binary mixtures onto cellulose has been carried out in the presence of Ce(IV) ions in acidic media at 30 +/- 0.1 degrees C. The graft copolymerization has shown an increasing trend on increasing the feed molarity of the comonomers and on increasing the reaction time. The analysis of grafted cellulose prepared with different feed compositions (f(AN)) has clearly indicated the existence of the synergistic effect of ethyl methacrylate on acrylonitrile which normally shows poor affinity for grafting on cellulose while used individually. The elemental analysis and IR data were used to determine the composition of grafted copolymers and reactivity ratios (r(1), r(2)) of the monomers using the Mayo and Lewis method. The reactivity ratios for acrylontrile and ethyl methacrylate have been found to be 0.68 and 1.15, respectively, which supported the alternate arrangement of the monomer blocks of individual monomers in the grafted chains. The rate of grafting has shown a square dependence on the concentration of the comonomers within the studied range of feed molarity from 0.5 to 2.5 mol dm(-3). The grafting data were used to calculate the number of grafted chains (N(g)), frequency of grafting (G(F)) per molecule of the cellulose and efficiency of grafting (G(E)). The variation in these parameters as a function of feed molarity, feed composition, and ceric ion concentration has been determined. The rate of ceric ion disappearance as a function of feed molarity and reaction time has provided strong support to consider the participation of ceric ions in the formation of free radicals at the backbone of the cellulose. On the basis of the experimental observations, reaction steps for grafting of monomers on cellulose have been proposed.

Cytokeratin 19 immunoreactivity in the diagnosis of papillary thyroid carcinoma: a note of caution

To evaluate the expression of cytokeratin (CK) 19, we stained sections obtained from formalin-fixed, paraffin tissue blocks of 35 thyroid tumors (follicular adenoma [FA], 20; papillary thyroid carcinoma [PTC], 10 follicular variant [FV] and 5 usual type) and scored the extent of staining as follows: 1+ (<5% positively stained cells), 2+ (5%-25% positively stained cells), 3+ (25%-75% positively stained cells), and 4+ (>75% positively stained cells). All 15 PTCs (including 10 FV-PTCs) were CK19 positive: 14 were 4+ and 1 (FV-PTC) was 2+. All 20 FAs also were CK19 positive: 15 were 1+, 1 was 2+, 4 were 3+, and none was 4+. In the FAs that were scored 1+, reactivity usually was confined to follicular cells lining cystically dilated atrophic follicles that lacked the typical nuclear features of PTC. The remaining FAs showed more diffuse reactivity, which was, however, less intense than that observed in the PTCs. Thus, immunoreactivity for CK19 is not specific for PTC, although we acknowledge that the extent and intensity of staining are considerably greater in this tumor than in FA. There were no significant differences in staining for CK19 between nonneoplastic follicles adjacent to PTCs and those adjacent to FAs.

Improvement in enzyme productivities from mold cultivations using the liquid-phase oxygen supply strategy

Cultivations of Aspergillus niger cells in which oxygen was provided through the liquid-phase oxygen supply strategy (which involves the need-based decomposition of H2O2 pulses to yield the necessary oxygen) were studied. Concentrations of H2O2 in the range of 1 to 5 mM were found to be suitable for use in cultivations. The growth rate constant of 0.17 h(-1) obtained in the H2O2-based cultivation, was comparable to that obtained in the cultivation with aeration; however, the maximum cell concentration in the H2O2-based cultivation was 124% of that obtained in cultivation with aeration. Maximum concentrations of catalase, protease and glucose oxidase obtained in the H2O2-based cultivation, were 240%, 172%, and 124% respectively, of those obtained in the cultivation with aeration. Further, the specific enzyme levels (units per gram cell) of catalase and protease obtained in the H2O2-based cultivation were 172% and 156% of those obtained in the cultivation with aeration, whereas, the specific glucose oxidase levels were comparable. In addition, the oxygen profiles inside the pellets ofA. niger during both the modes of oxygen supply were described using mathematical models. Studies to elucidate the mechanism of oxygen availability showed that the decomposition of the H2O2 supplied in the extracellular space occurred intracellularly, as well as extracellularly, to yield oxygen. Also, the proton motive force (PMF) was found to be involved in the process of oxygen availability from H2O2 to A. niger cells.

Metastatic prostatic adenocarcinoma within a primary solid papillary carcinoma of the male breast

We report the case of a 78-year-old man who developed a breast mass 12 months after hormonal therapy for palliation of prostatic adenocarcinoma. On histologic and immunohistochemical examination, the breast tumor revealed a unique collision tumor composed of metastatic prostatic adenocarcinoma and solid papillary breast carcinoma.