CT angiography of pulmonary embolism: diagnostic criteria and causes of misdiagnosis.

Computed tomographic (CT) pulmonary angiography is becoming the standard of care at many institutions for the evaluation of patients with suspected pulmonary embolism. This pathologic condition, whether acute or chronic, causes both partial and complete intraluminal filling defects, which should have a sharp interface with intravascular contrast material. In acute pulmonary embolism that manifests as complete arterial occlusion, the affected artery may be enlarged.

The active site and substrate-binding mode of 1-aminocyclopropane-1-carboxylate oxidase determined by site-directed mutagenesis and comparative modelling studies.

The active site and substrate-binding mode of MD-ACO1 (Malus domestica Borkh. 1-aminocyclopropane-1-carboxylate oxidase) have been determined using site-directed mutagenesis and comparative modelling methods. The MD-ACO1 protein folds into a compact jelly-roll motif comprised of eight a-helices, 12 b-strands and several long loops.

Cluster Analyzer for Transcription Sites (CATS): a C++-based program for identifying clustered transcription factor binding sites.

Summary: We have developed a program, Cluster Analyzer for Transcription Sites (CATS), which identifies clusters of transcription factor binding sites in any genome sequence. The program searches for clusters of the consensus sequence for DNA binding within a window (length of DNA). The window size and the cluster size (number of consensus sequences within a given window) can be varied.

Crosstalk between the EGFR and LIN-12/Notch pathways in C. elegans vulval development.

The Caenorhabditis elegans vulva is an important paradigm for cell-cell interactions in animal development. The fates of six vulval precursor cells are patterned through the action of the epidermal growth factor receptor-mitogen-activated protein kinase (EGFR-MAPK) inductive signaling pathway, which specifies the 1 degrees fate, and the LIN-12/Notch lateral signaling pathway, which specifies the 2 degrees fate. Here, we provide evidence that the inductive signal is spatially graded and initially activates the EGFR-MAPK pathway in the prospective 2 degrees cells.

Presenilin-mediated modulation of capacitative calcium entry.

We studied a novel function of the presenilins (PS1 and PS2) in governing capacitative calcium entry (CCE), a refilling mechanism for depleted intracellular calcium stores. Abrogation of functional PS1, by either knocking out PS1 or expressing inactive PS1, markedly potentiated CCE, suggesting a role for PS1 in the modulation of CCE. In contrast, familial Alzheimer's disease (FAD)-linked mutant PS1 or PS2 significantly attenuated CCE and store depletion-activated currents.

Process extension and intracellular Ca2+ in cultured murine oligodendrocytes.

Previous investigations have shown that phorbol esters stimulate process extension in oligodendrocytes (OL), likely by the activation of protein kinase C (PKC). In this report, we demonstrate that treatment of OL with 4beta-phorbol-12, 13-dibutyrate (PDB; 0.1-1 microM) resulted in an increase in intracellular Ca2+ concentration ([Ca2+]i) from 94+/-2 nM (mean+/-S.

Effects of calcium depletion and repletion on serum insulin-like growth factor I and binding protein levels in weanling rats.

Previous studies in a weanling rat model indicated that dietary calcium depletion not only stimulated osteoclastic resorption but also inhibited bone formation. The present study sought to test whether the depletion-associated inhibition of bone formation is related to a reduction in serum insulin-like growth factor-I (IGF-I) and/or an increase in its binding proteins (IGFBPs). Twenty male weanling rats were divided into two weight-matched groups.

Effects of phorbol ester on intracellular Ca2+ and membrane currents in cultured human microglia.

The effects of protein kinase C (PKC) activation by phorbol ester on intracellular Ca2+ concentration ([Ca2+]i) and membrane currents in human microglia grown in culture were investigated. Treatment of microglia with phorbol myristate acetate (PMA) resulted in a large increase in [Ca2+]i in cells loaded with fura-2. The increased levels of [Ca2+]i were not altered following removal of the phorbol ester.

Dose-response study of dehydroepiandrosterone sulfate on dentate gyrus long-term potentiation.

Neurosteroids are produced peripherally by endocrine glands, as well as enzymatically in the glia from steroid hormone substrates. GABA receptor sites and Ca2+ channel currents are prime targets for neurosteroid actions, and their effects are concentration dependent. For this reason, and the fact that treatment with one of them, sulfated dehydroepiandrosterone (DHEAS), improves performance in tasks involving memory in aged rats, we explored the effect of this hormone on dentate gyrus long term potentiation (LTP) in a dose-response mode.

Mechanism of mitogenic action of aluminum ion on human bone cells: potential involvement of the insulin-like growth factor regulatory system.

Aluminum ion at micromolar concentrations significantly stimulated the [3H]thymidine incorporation into human TE85 osteosarcoma cell DNA. Cells treated with mitogenic concentrations of aluminum ion for 48 h showed biphasic stimulation in secretion of IGFs (insulin-like growth factors) into the conditioned medium. Treatment of the human osteosarcoma TE85 cells with mitogenic doses of aluminum ion for 24 h also markedly and reproducibly increased the steady-state level of IGF-II mRNA in a dose-dependent, biphasic manner.

Human astrocytes and cytokines: tumor necrosis factor alpha and interferon gamma do not promote astrocytic proliferation.

Astrocyte cell cultures were established from human fetal brains and exposed to human recombinant tumor necrosis factor alpha (TNF alpha) and human recombinant interferon gamma (IFN gamma), and the proliferative response was assessed by bromodeoxyuridine-immunostaining technique. TNF alpha showed an inhibitory activity, while IFN gamma induced a slight increase in the number of astrocytes undergoing cell division. However, in both experiments differences were not statistically significant.

Conversion of skeletal tartrate-sensitive acid phosphatases into tartrate-resistant isoenzymes in vitro.

1. Chicken skeletal tartrate-sensitive (TsACP) and -resistant (TrACP) acid phosphatase isoenzymes could be separated from each other by carboxylmethyl-sepharose ion exchange chromatography. 2.

Aluminum stimulates the proliferation and differentiation of osteoblasts in vitro by a mechanism that is different from fluoride.

Micromolar concentrations of aluminum sulfate consistently stimulated [3H]thymidine incorporation into DNA and increased cellular alkaline phosphatase activity (an osteoblastic differentiation marker) in osteoblast-line cells of chicken and human. The stimulations were highly reproducible, and were biphasic and dose-dependent with the maximal stimulatory dose varied from experiment to experiment. The mitogenic doses of aluminum ion also stimulated collagen synthesis in cultured human osteosarcoma TE-85 cells, suggesting that aluminum ion might stimulate bone formation in vitro.

The synthesis of some lipophilic tetra-arylborates for use in membrane electrode preparation.

Synthetic methods for preparing four lipophilic tetra-arylborates considered suitable candidates for use in membrane electrodes are described. Qualitative precipitation tests were performed with several cations. The sodium salts of the four tetra-arylborates were found to have limited stability but the cesium salts were relatively stable.

Evidence that tartrate-resistant acid phosphatases from osteoclastomas and hairy cell leukemia spleen are members of a multigene family.

1. Osteoclasts and hairy cell leukemia spleen both contain large amounts of a band 5-tartrate-resistant acid phosphatase (TrACP). 2.