Subcellular second messenger networks drive distinct repellent-induced axon behaviors.

Second messengers, including cAMP, cGMP and Ca are often placed in an integrating position to combine the extracellular cues that orient growing axons in the developing brain. This view suggests that axon repellents share the same set of cellular messenger signals and that axon attractants evoke opposite cAMP, cGMP and Ca changes. Investigating the confinement of these second messengers in cellular nanodomains, we instead demonstrate that two repellent cues, ephrin-A5 and Slit1, induce spatially segregated signals.

Non invasive jacketed telemetry in socially-housed rats for a combined assessment of respiratory system, electrocardiogram and activity using the DECRO system.

Respiratory and cardiovascular systems are among the vital organ systems that should be studied in safety pharmacology core battery test. Non-invasive jacketed external telemetry technology that enables concomitant monitoring of both systems has been available and used widely for non-rodent species. Recently, the DECRO system, a miniaturized technology system in line with the "3Rs" principles, has been developed to provide a similar approach in rats.

cAMP-Dependent Co-stabilization of Axonal Arbors from Adjacent Developing Neurons.

Axonal arbors in many neuronal networks are exuberant early during development and become refined by activity-dependent competitive mechanisms. Theoretical work proposed non-competitive interactions between co-active axons to co-stabilize their connections, but the demonstration of such interactions is lacking. Here, we provide experimental evidence that reducing cyclic AMP (cAMP) signaling in a subset of retinal ganglion cells favors the elimination of thalamic projections from neighboring neurons, pointing to a cAMP-dependent interaction that promotes axon stabilization.

SpiCee: A Genetic Tool for Subcellular and Cell-Specific Calcium Manipulation.

Calcium is a second messenger crucial to a myriad of cellular processes ranging from regulation of metabolism and cell survival to vesicle release and motility. Current strategies to directly manipulate endogenous calcium signals lack cellular and subcellular specificity. We introduce SpiCee, a versatile and genetically encoded chelator combining low- and high-affinity sites for calcium.

Approaches to Manipulate Ephrin-A:EphA Forward Signaling Pathway.

Erythropoietin-producing hepatocellular carcinoma A (EphA) receptors and their ephrin-A ligands are key players of developmental events shaping the mature organism. Their expression is mostly restricted to stem cell niches in adults but is reactivated in pathological conditions including lesions in the heart, lung, or nervous system. They are also often misregulated in tumors.

SponGee: A Genetic Tool for Subcellular and Cell-Specific cGMP Manipulation.

cGMP is critical to a variety of cellular processes, but the available tools to interfere with endogenous cGMP lack cellular and subcellular specificity. We introduce SponGee, a genetically encoded chelator of this cyclic nucleotide that enables in vitro and in vivo manipulations in single cells and in biochemically defined subcellular compartments. SponGee buffers physiological changes in cGMP concentration in various model systems while not affecting cAMP signals.

Cytokine profile in human eyes: contribution of a new cytokine combination for differential diagnosis between intraocular lymphoma or uveitis.

Primary intraocular lymphoma (PIOL), also called primary vitreoretinal lymphomas, often masquerades as uveitis. This misdiagnosis can result in subsequent brain involvement and oculocerebral lymphoma (OCL). In this study, we sought to characterize the helper T-cell type 1 (Th1)/Th2 cytokine profile in vitreous samples from patients with PIOL, OCL, uveitis and controls with non-inflammatory disease.

Making and using calcium-selective mini- and microelectrodes.

Detection and measurement of intracellular calcium concentration ([Ca(2+)](i)) have relied on various methods, the popularity of which depends on their ease of use and applicability to different cell types. Historically, Ca(2+)-selective electrodes have been used concomitantly with absorption indicators such as arsenazo-III, but their interest has been eclipsed by the introduction of a large number of fluorescent calcium probes with calcium sensitivities varying from the nanomolar to the micromolar range such as fura-2, indo-1, fluo-4, and many others. In this chapter, we emphasize the utility of Ca(2+)-selective electrodes and show that their use is complementary to use of fluorescent indicators; indeed, each method has advantages and disadvantages.

A study of bone marrow neoangiogenesis in chronic lymphocytic leukemia patients.

Objective: To use a purely geometric data-unravelling method to identify, without a priori, direct links of neoangiogenesis with known clinicobiologic variables in 23 untreated chronic lymphocytic leukemia (CLL) patients at the time of marrow sampling.

Study Design: We measured neovascular surface density (CD34 endothelial marker) in the 10 most labeled fields (hVA), cellularity (CA) and the percentage of avascular fields (AVF) in bone marrow biopsy specimens from 34 patients with CLL. Vascular endothelial growth factor (VEGF) was assayed in thawed serum samples from 8 of the 23 untreated patients (12 Rai stage 0, 6 Rai stage I-II, 5 Binet stage B-C).

Caspase-independent type III programmed cell death in chronic lymphocytic leukemia: the key role of the F-actin cytoskeleton.

Background: Programmed cell death has been traditionally related with caspase activation. However, it is now accepted that caspase-independent forms of programmed cell death also regulate cell death. In chronic lymphocytic leukemia, CD47 ligation induces one of these alternative forms of cell death: type III programmed cell death.

Drp1 mediates caspase-independent type III cell death in normal and leukemic cells.

Ligation of CD47 triggers caspase-independent programmed cell death (PCD) in normal and leukemic cells. Here, we characterize the morphological and biochemical features of this type of death and show that it displays the hallmarks of type III PCD. A molecular and biochemical approach has led us to identify a key mediator of this type of death, dynamin-related protein 1 (Drp1).

IL-10 measurement in aqueous humor for screening patients with suspicion of primary intraocular lymphoma.

Purpose: To determine the value of IL-10 measurement in aqueous humor (AH) for screening in primary intraocular lymphoma (PIOL).

Methods: One hundred consecutive diagnostic or therapeutic vitrectomies were performed in patients with uveitis. During surgery, 100 microL of both AH and pure vitreous was taken.

Biological diagnosis of primary intraocular lymphoma.

Primary intraocular lymphoma (PIOL) is a rare presentation of lymphoma that is particularly difficult to recognize. In our institution, 36 cases of PIOL were diagnosed between March 1997 and July 2002. The recognition of lymphoma cells by cytology with or without immunophenotyping on slides generated a strong suspicion of the diagnosis in 34 of 36 cases.

Novel flow-cytometric analysis based on BCD5+ subpopulations for the evaluation of minimal residual disease in chronic lymphocytic leukaemia.

We describe a new flow-cytometric analysis using quadruple labelling with anti-CD19, CD20, CD5, CD79b monoclonal antibodies and sequential gating. We determined a novel criteria defined by BCD5+CD79b-/low/total BCD5+ cells ratio (BCD5+R), and compared it with the previous definition of phenotypic remission, based on CD19+CD5+ coexpression, and with complementarity-determining region 3 polymerase chain reaction (CDR3 PCR) and clonotypic PCR (cPCR). A series of 54 peripheral blood samples from 21 chronic lymphocytic leukaemia (CLL) patients in complete haematological remission and a series of 16 from normal volunteers were analysed.

Sildenafil and vardenafil, types 5 and 6 phosphodiesterase inhibitors, induce caspase-dependent apoptosis of B-chronic lymphocytic leukemia cells.

Type 4 phosphodiesterase (PDE4) inhibitors reportedly induce apoptosis in chronic lymphocytic leukemia (CLL) cells. Following clinical improvement of one previously untreated CLL patient with sildenafil therapy, we evaluated the in vitro induction of apoptosis in CLL cells by 4 PDE5/6 inhibitors, including sildenafil, vardenafil, zaprinast, and methoxyquinazoline (MQZ). After 24 hours of culture, the various PDE inhibitors differed in their ability to induce apoptosis, with zaprinast displaying no killing effect.

Effect of short-term octreotide therapy and total parenteral nutrition on the development of biliary sludge and lithiasis.

Background/aims: Both total parenteral nutrition and long-term octreotide treatment (> 2 months) may induce biliary sludge and lithiasis. However, the lithogenic capacity of the combination of the two treatments in the short-term is unknown. This study was undertaken to evaluate the lithogenic capacity of short-term octreotide treatment (< 1 month) in patients with acute pancreatitis who are also receiving total parenteral nutrition, and to determine the evolution of patients who develop biliary sludge and/or lithiasis.

Prognostic relevance of a scoring system based on clinical and biological parameters in early chronic lymphocytic leukemia.

Introduction: Among patients with indolent form of B-cell chronic lymphocytic leukemia, some of them will progress into more advanced stages. To better define this subpopulation of patients, we attempted to define some parameters capable of predicting a pejorative clinical outcome.

Materials And Methods: Eighty-eight previously untreated patients with B-cell chronic lymphocytic leukemia in Binet stage A were analysed to study the prognostic value of simple serological variables: soluble CD23 (sCD23), beta2 microglobulin (beta2m), lactate-dehydrogenase activities and albumin level.

Increased basal contractility of cardiomyocytes overexpressing protein kinase C epsilon and blunted positive inotropic response to endothelin-1.

Objective: Protein kinase C (PKC) is thought to be involved in the regulation of the mammalian cardiac excitation-contraction coupling process by vasoactive peptides like endothelin-1 (ET-1). However, the demonstration of a causal link between activation of specific PKC isoforms and the increase in contractility mediated by ET-1 is still inferential.

Methods: By means of adenovirus-mediated gene transfer, we specifically overexpressed PKC epsilon in cultured adult rabbit ventricular myocytes (Ad-PKC epsilon).

Pharmacologic evaluation of isometric contraction-relaxation coupling indexes in rabbit ventricular muscle.

Investigations of the coupling between contraction and relaxation (contraction-relaxation [CRC] process) in isometric conditions are essential in determining whether pharmacologic interventions or cardiac diseases specifically modify isometric relaxation (intrinsic lusitropic effect) or change it in proportion with the accompanying changes in contractility (or inotropy). For this purpose, the CRC process is quantified by various indexes, derived from differentiation and/or curve fitting the whole or relaxation phase of the isometric twitch, one of the most used being tau, the time constant of the final iso(volu)metric phase of relaxation. Nevertheless, the possible redundancy and validity of such indexes have not been thoroughly investigated.

In situ study of the sarcoplasmic reticulum function in control and mdx mouse diaphragm muscle.

Sarcoplasmic reticulum (SR) calcium handling in diaphragm was compared between mdx mice (7-8 weeks old) and age-matched controls. The total SR Ca2+ load was released from the SR by rapidly cooling muscle bundles from 22 to -1 degree C. The plateau amplitude of the rapid cooling contracture (RCC) was considered as an index of the SR Ca2+ content.

Changes in resting membrane potential induced by active sensitization in the guinea-pig vas deferens.

Smooth muscles hyperresponsiveness is a common feature in anaphylaxis and allergic diseases. The aim of the present work was to investigate whether the enhanced reactivity of sensitized guinea-pig vas deferens was associated with changes in the resting membrane potential (Er) of the smooth muscle cells. Active sensitization was performed by subcutaneous injection of egg albumen.

Quantification of apoptosis by the Abbott CD4000 hematology analyzer.

We propose a simple and fast method of detecting apoptosis using an automated hematology analyzer. Detection is based on cellular optical light scatter properties and demonstration of the membrane fragility which characterizes cells undergoing the process of apoptosis. As part of it's routine leucocyte differential analysis, the Abbott Cell-Dyn 4000 collects multi-angle cellular light scatter data.