Abrupt (< 1 day), acute (< 1 week), and early (< 1 month) vessel closure at the angioplasty site. Morphologic observations and causes of closure in 130 necropsy patients undergoing coronary angioplasty

While abundant clinical and angiographic data are available regarding features of acute or abrupt closure at the site of balloon angioplasty, little morphologic information is available. This study discusses morphologic-histologic causes for acute closure after angioplasty in 130 necropsy patients. Intimal-medial flaps, elastic recoil, and primary thrombosis were the three leading morphologic causes for closure. Data were subdivided into time categories: abrupt (< 1 day), acute (< 1 week), and early (< 1 month). Intimal-medial flaps remained the most common cause for angioplasty closure despite time from angioplasty to documented occlusion. Morphologic recognition of types and frequencies of angioplasty closure are discussed, and specific mechanical, pharmacologic, or combined treatments are reviewed.     

Cytochrome P450 and dependent activities in unexposed and PAH-exposed terrestrial annelids

The cytochrome P450 system of the oligochaetes Eisenia f. fetida (tiger worm) and Enchytraeus crypticus (pot worm) was analysed using ethoxy-, pentoxy- and benzoxyresorufin as substrates for monooxygenase activity. Whole body microsomes of the earthworm E.f. fetida displayed PentROD activity in the range from 0.26 to 1.05 pmol mg protein-1 min-1 and BenzROD activity in the range from 0.14 to 0.30 pmol mg protein-1 min-1. Exposure of the animals for up to four weeks to 100 mg fluoranthene or benzo[a]pyrene kg-1 soil (dry weight) did not induce significant changes in the activity of these monooxygenases. In E. crypticus EROD activity was in the range from 2.10 to 6.18 pmol mg protein-1 min-1 and PentROD activity in the range from 1.75 to 4.78 pmol mg protein-1 min-1. Short-term exposure to BaP by feeding reduced the EROD activity significantly by 45%, but did not effect PentROD activity. After long-term (8 weeks) exposure to BaP in the agar-agar medium EROD activity was not changed but PentROD had decreased to zero. In both species cytochrome P420 and NADPH-cytochrome C reductase activity were present. In E.f. fetida microsomes are associated with the giant haemoglobin. Both can be separated by gel filtration on a Sepharose B2 column or by hydrophobic interaction chromatography after solubilisation with cholate. NADPH-cytochrome C reductase elutes together with haemoglobin. Cytochrome P420 is eluted with Emulgen 911 and can be further purified by ion exchange chromatography using HA-Ultrogel. By SDS-PAGE of the purified microsomal proteins three protein bands are visualised in the range of cytochrome P450 displaying an apparent molecular mass of 54, 56 and 58 kDa. Only the 54-kDa protein interacts weakly with perch (Perca fluviatilis) CYP1A antibodies, while two proteins with an apparent molecular mass of 65 and 71 kDa give a strong antibody signal.     

Equilibrium distribution of water in the two-phase system supercritical carbon dioxide–textile

When natural fibres are dyed in supercritical carbon dioxide, the addition of a small amount of water increases coloration. For a process design it is important to know how much water has to be added to obtain a desired humidity of both textile and carbon dioxide. In this work a thermodynamic model is proposed to calculate the distribution of water over the textile phase and the supercritical phase as a function of pressure and temperature. The phase equilibrium is described with Raoult's law for non-ideal fluids. The absorbed water in the textile is a condensed phase and is modelled here as a non-ideal liquid, using the NRTL-equation. The non-ideality of the supercritical phase is described by a solubility enhancement factor, a new equation derived from statistical thermodynamics. Although the model is applied to cotton, viscose, silk and wool, it can be used for all water absorbing textiles.     

Development of technologies aiding large-tissue engineering

Apoptosis associated oligonucleosomal fragmentation of DNA can result from the activation of endonucleases that exhibit different pH optima and are either sensitive or insensitive to divalent cations. DNA fragmentation due to activation of cation sensitive endonucleases occurs in the absence of a change in intracellular pH whereas intracellular acidification is a feature of apoptosis characterized by activation of cation insensitive acidic endonuclease. We have reported earlier that somatostatin (SST) induced DNA fragmentation and apoptosis is signaled in a receptor subtype selective manner uniquely via human somatostatin receptor subtype 3 (hSSTR3). In the present study we investigated the pH dependence and cation sensitivity of endonuclease induced in hSSTR3 expressing CHO-K1 cells by the SST agonist octreotide (OCT) and its effect on intracellular pH. We show that OCT induced apoptosis is associated with selective stimulation of a divalent cation insensitive acidic endonuclease. The intracellular pH of of cells undergoing OCT induced apoptosis was 0.9 pH units lower than that of control cells. The effect of OCT on endonuclease and pH was inhibited by orthovanadate as well as by pretreatment with pertussis toxin, suggesting that hSSTR3 initiated cytotoxic signaling is protein tyrosine phosphatase mediated and is G protein dependent. These findings suggest that intracellular acidification and activation of acidic endonuclease mediate wild type p53 associated apoptosis signaled by hormones acting via G protein coupled receptors.     

Duodenoesophageal reflux induces esophageal adenocarcinoma without exogenous carcinogen

Central nervous system (CNS) disease is a major feature of simian immunodeficiency virus (SIV) infection of macaques. To define the spectrum of CNS lesions in SIV-infected macaques and the potential associations with viral strain and disease course, we performed a retrospective analysis of necropsies on 124 macaques with SIV-induced AIDS. Histologic evidence of CNS disease was observed in 71 (57.3%) of the 124 animals. SIV encephalitis was the most common CNS lesion occurring in 43.7% (31/71) of the animals with CNS disease and 25% of all animals. The incidence of SIVE correlated significantly with shortened survival (P=0.0207). In addition, SIVE was seen in 42.9% (15/35) of rapid progressors (animals that died within 200 days) compared to only 18% (16/89) of normal progressors (animals that lived longer than 200 days) (P=0.011). Animals with SIVE had higher viral loads in peripheral blood than those that did not, but this difference did not reach statistical significance. Similarly, while animals infected with uncloned SIVmac251 had a higher incidence of SIVE (27.5%; 14/51) than animals infected with molecularly cloned SIVmac239 and its T-cell tropic derivatives (18.5%; 10/54) this difference was not statistically significant. In this study rapid disease progression and SIVE were highly correlated making separation of viral determinants of virulence from those of neurovirulence difficult.     

Mechanism of action of the nongenotoxic peroxisome proliferators: role of the peroxisome proliferator-activator receptor alpha

Peroxisome proliferators are a diverse group of chemicals that include several therapeutically used drugs (e.g., hypolipidemic agents), plasticizers and organic solvents used in the chemical industry, herbicides, and naturally occurring hormones. As the name implies, peroxisome proliferators cause an increase in the number and size of peroxisomes in the liver, kidney, and heart tissue of susceptible species, such as rats and mice. Long-term administration of peroxisome proliferators can cause liver cancer in these animals, a response that has been the central issue of research on peroxisome proliferators for many years. Peroxisome proliferators are representative of the class of nongenotoxic carcinogens that cause cancer through mechanisms that do not involve direct DNA damage. The fact that humans are frequently exposed to these agents makes them of particular concern to government regulatory agencies responsible for assuring human safety. Whether frequent exposure to peroxisome proliferators represents a hazard to humans is unknown; however, increased cancer risk has not been shown to be associated with long-term therapeutic administration of the hypolipidemic drugs gemfibrozil, fenofibrate, and clofibrate. To make sound judgments regarding the safety of peroxisome proliferators, the validity of extrapolating results from rodent bioassays to humans must be based on the agents' mechanism of action and species differences in biologic activity and carcinogenicity. The peroxisome proliferator-activated receptor alpha (PPARalpha), a member of the nuclear receptor superfamily, has been found to mediate the activity of peroxisome proliferators in mice. Gene-knockout mice lacking PPARalpha are refractory to peroxisome proliferation and peroxisome proliferator-induced changes in gene expression. Furthermore, PPARalpha-null mice are resistant to hepatocarcinogenesis when fed a diet containing a potent nongenotoxic carcinogen WY-14,643. Recent studies have revealed that humans have considerably lower levels of PPARalpha in liver than rodents, and this difference may, in part, explain the species differences in the carcinogenic response to peroxisome proliferators.     

Antimetabolite-induced increases in the invasive capacity of murine leukaemia L1210 cells

Pretreatment of murine leukaemia L1210 cells with non-lethal concentrations of various antimetabolites increased the in vitro invasive capacity of these cells into monolayers of rat embryo fibroblasts. The increase in invasive capacity was partly correlated with the induced cell cycle arrest. The concomitant increase in cell surface fucosylation and inhibition of invasion with sulphate indicate a role for glycoproteins in this process. Our results suggest that treatment with antimetabolites may lead to a more aggressive phenotype by altering cell surface properties.     

Real-time detection of colored objects in multiple camera streams with off-the-shelf hardware components

We describe RTblob, a high speed vision system that detects objects in cluttered scenes based on their color and shape at a speed of over 800 frames/s. Because the system is available as open-source software and relies only on off-the-shelf PC hardware components, it can provide the basis for multiple application scenarios. As an illustrative example, we show how RTblob can be used in a robotic table tennis scenario to estimate ball trajectories through 3D space simultaneously from four cameras images at a speed of 200 Hz.     

hp-version finite elements for the space-time domain

A bilinear formulation of elasto-dynamics is offered which includes, as a special case, Hamilton's law of varying action. However, the more general bilinear formulation has several advantages over Hamilton's law. First, it admits a larger class of initial-value and boundary-value problems. Second, in its variational form, it offers physical insight into the so-called trailing terms of Hamilton's law. Third, numerical applications (i.e., finite elements in time) can be proven to be convergent under correct application of the bilinear formulation, whereas they can be demonstrated to diverge for specific problems under Hamilton's law. Fourth, the bilinear formulation offers automatic convergence of the natural velocity end conditions; while these must be constrained in present applications of Hamilton's law. Fifth, the bilinear formulation can be implemented in terms of a Larange multiplier that gives an order of magnitude improvement in the convergence of velocity. This implies that, in this form, the method is a hybrid finite-element approach.List of symbols b arbitrary constant - A _i, A _i vector of integrals, i = 0, j - A() linear operator on - () Hamilton's form of A - B (u, ) bilinear operator u, - B (u, ) Hamilton's form of B - B _i,j , B _ij , B _ij matrix of integrals - C constant, N/m - c number of floating-point operations per coef. evaluation - f, f(x) force per unit length, N/m - F, F ₀, F _L forces, N - J number of functions in series for û - k spring rate per unit length, N/m² - K spring rate, N/m - K _max maximum value of K - L _a Lagrangian, non-dimensional - L length of beam, m - m mass per unit length, kg/m - M mass, kg - M _max maximum value of M - n number of functions in series for - N number of elements in domain - p momentum density, kg/sec - P, P ₀, P _T momentum, kg-m/sec - q _i generalized coordinates - r _j coefficients of _j - t time, sec - t ₀, t ₁ limits of action integral, Hamilton's law - T end of time period, sec - u solution for displacement, m - û approximation to u, m - u ₀ initial value for u, m - test function, m - limited class of , m - x spatial coordinate, m - flapping angle, rad - Lock number - time increment, sec - Lagrange multiplier - longitudinal stiffness EA, N (Eqs. 1–18) - advance ratio of rotor (Eqs. 33–34 and figures) - _i , _r polynomial functions - non-dimensional time, azimuth angle - () variation of ( ) - W virtual work - ( ) d ( )/dx - ( .) d ( )/dt - (*) d/d - [ ] matrix - { } column vector - row vector