Stress signalling in acellular slime moulds and its detection by conspecifics

Unicellular organisms live in unpredictable environments. Therefore, they need to continuously assess environmental conditions and respond appropriately to survive and thrive. When subjected to rapid changes in their environment or to cellular damages, unicellular organisms such as bacteria exhibit strong physiological reactions called stress responses that can be sensed by conspecifics. The ability to detect and use stress-related cues released by conspecifics to acquire information about the environment constitutes an adaptive survival response by prompting the organism to avoid potential dangers. Here, we investigate stress signalling and its detection by conspecifics in a unicellular organism, Physarum polycephalum. Slime moulds were subjected to either biotic (i.e. nutritional) or abiotic (i.e. chemical and light) stressors or left undisturbed while they were exploring a homogeneous environment. Then, we observed the responses of slime moulds facing a choice between cues released by stressed clone mates and cues released by undisturbed ones. We found that slime moulds actively avoided environments previously explored by stressed clone mates. These results suggest that slime moulds, like bacteria or social amoeba, exhibit physiological responses to biotic and abiotic stresses that can be sensed by conspecifics. Our results establish slime moulds as a promising new model to investigate the use of social information in unicellular organisms. This article is part of the theme issue 'Signal detection theory in recognition systems: from evolving models to experimental tests'.

A Business Rules Design Framework for a Pharmaceutical Validation and Alert System

Objectives: Several alert systems have been developed to improve the patient safety aspects of clinical information systems (CIS). Most studies have focused on the evaluation of these systems, with little information provided about the methodology leading to system implementation. We propose here an ‘agile’ business rule design framework (BRDF) supporting both the design of alerts for the validation of drug prescriptions and the incorporation of the end user into the design process.

Methods: We analyzed the unified process (UP) design life cycle and defined the activities, subactivities, actors and UML artifacts that could be used to enhance the agility of the proposed framework. We then applied the proposed framework to two different sets of data in the context of the Georges Pompidou University Hospital (HEGP) CIS.

Results: We introduced two new subactivities into UP: business rule specification and business rule instantiation activity. The pharmacist made an effective contribution to five of the eight BRDF design activities. Validation of the two new subactivities was effected in the context of drug dosage adaption to the patients’ clinical and biological contexts. Pilot experiment shows that business rules modeled with BRDF and implemented as an alert system triggered an alert for 5824 of the 71,413 prescriptions considered (8.16%).

Conclusion: A business rule design framework approach meets one of the strategic objectives for decision support design by taking into account three important criteria posing a particular challenge to system designers: 1) business processes, 2) knowledge modeling of the context of application, and 3) the agility of the various design steps.

Stromal SLIT2 impacts on pancreatic cancer-associated neural remodeling

Pancreatic ductal adenocarcinoma (PDA) is a critical health issue in the field of cancer, with few therapeutic options. Evidence supports an implication of the intratumoral microenvironment (stroma) on PDA progression. However, its contribution to the role of neuroplastic changes within the pathophysiology and clinical course of PDA, through tumor recurrence and neuropathic pain, remains unknown, neglecting a putative, therapeutic window. Here, we report that the intratumoral microenvironment is a mediator of PDA-associated neural remodeling (PANR), and we highlight factors such as 'SLIT2' (an axon guidance molecule), which is expressed by cancer-associated fibroblasts (CAFs), that impact on neuroplastic changes in human PDA. We showed that 'CAF-secreted SLIT2' increases neurite outgrowth from dorsal root ganglia neurons as well as from Schwann cell migration/proliferation by modulating N-cadherin/β-catenin signaling. Importantly, SLIT2/ROBO signaling inhibition disrupts this stromal/neural connection. Finally, we revealed that SLIT2 expression and CAFs are correlated with neural remodeling within human and mouse PDA. All together, our data demonstrate the implication of CAFs, through the secretion of axon guidance molecule, in PANR. Furthermore, it provides rationale to investigate the disruption of the stromal/neural compartment connection with SLIT2/ROBO inhibitors for the treatment of pancreatic cancer recurrence and pain.

Dual roles of hemidesmosomal proteins in the pancreatic epithelium: the phosphoinositide 3-kinase decides

Given the failure of chemo- and biotherapies to fight advanced pancreatic cancer, one major challenge is to identify critical events that initiate invasion. One priming step in epithelia carcinogenesis is the disruption of epithelial cell anchorage to the basement membrane which can be provided by hemidesmosomes (HDs). However, the existence of HDs in pancreatic ductal epithelium and their role in carcinogenesis remain unexplored. HDs have been explored in normal and cancer pancreatic cells, and patient samples. Unique cancer cell models where HD assembly can be pharmacologically manipulated by somatostatin/sst2 signaling have been then used to investigate the role and molecular mechanisms of dynamic HD during pancreatic carcinogenesis. We surprisingly report the presence of mature type-1 HDs comprising the integrin α6β4 and bullous pemphigoid antigen BP180 in the human pancreatic ductal epithelium. Importantly, HDs are shown to disassemble during pancreatic carcinogenesis. HD breakdown requires phosphoinositide 3-kinase (PI3K)-dependent induction of the matrix-metalloprotease MMP-9, which cleaves BP180. Consequently, integrin α6β4 delocalizes to the cell-leading edges where it paradoxically promotes cell migration and invasion through S100A4 activation. As S100A4 in turn stimulates MMP-9 expression, a vicious cycle maintains BP180 cleavage. Inactivation of this PI3K-MMP-9-S100A4 signaling loop conversely blocks BP180 cleavage, induces HD reassembly and inhibits cell invasion. We conclude that mature type-1 HDs are critical anchoring structures for the pancreatic ductal epithelium whose disruption, upon PI3K activation during carcinogenesis, provokes pancreatic cancer cell migration and invasion.

Electronic Healthcare Record and clinical research in cardiovascular radiology. HL7 CDA and CDISC ODM interoperability

Integrating clinical research data entry with patient care data entry is a challenging issue. At the G. Pompidou European Hospital (HEGP), cardiovascular radiology reports are captured twice, first in the Electronic Health Record (EHR) and then in a national clinical research server. Informatics standards are different for EHR (HL7 CDA) and clinical research (CDISC ODM). The objective of this work is to feed both the EHR and a Clinical Research Data Management System (CDMS) from a single multipurpose form. We adopted and compared two approaches. First approach consists in implementing the single "care-research" form within the EHR and aligning XML structures of HL7 CDA document and CDISC ODM message to export relevant data from EHR to CDMS. Second approach consists in displaying a single "care-research" XForms form within the EHR and generating both HL7 CDA document and CDISC message to feed both EHR and CDMS. The solution based on XForms avoids overloading both EHR and CDMS with irrelevant information. Beyond syntactic interoperability, a perspective is to address the issue of semantic interoperability between both domains.

Scaling of the structural relaxation in simulated liquid silica

A scaling law for the alpha relaxation time tau , involving the ratio of a density-dependent energy to the thermal energy, has been found to hold in many fragile glass-forming liquids. This scaling has been recently linked to a local quantity n{loc}(rho,T) relating the variation of tau with density to its variation with temperature. In many fragile liquids, the variation of n{loc}(rho,T) is weak enough to take it as constant over the experimental temperature and density domain. We show that simulated liquid silica has an opposite behavior; close to T{g}, n{loc} is negative for moderate densities and exhibits a significant variation with rho and T, reaching positive values for higher temperature and/or densities. Moreover, those variations linearly correlate to a measure of the bonding properties of the liquid.

Continuous supercritical synthesis and dielectric behaviour of the whole BST solid solution

In this study we show that pure and well crystallized nanoparticles of Ba(x)Sr(1-x)TiO(3) (BST) can be synthesized over the entire range of composition through the hydrolysis and further crystallization of alkoxide precursors under supercritical conditions. To our knowledge, this is the first time that the whole ferroelectric solid solution has been produced in a continuous way, using the same experimental conditions. The composition of the powder can be easily controlled by adjusting the feed solution composition. The powders consist of soft-aggregated monocrystalline nanoparticles with an average particle size ranging from approximately 20 to 40 nm. Ferroelectric ceramics with accurately adjustable Curie temperature (100-390 K) can thus be obtained by sintering.

Novel synergistic mechanism for sst2 somatostatin and TNFα receptors to induce apoptosis: crosstalk between NF-κB and JNK pathways

Somatostatin is a multifunctional hormone that modulates cell proliferation, differentiation and apoptosis. Mechanisms for somatostatin-induced apoptosis are at present mostly unsolved. Therefore, we investigated whether somatostatin receptor subtype 2 (sst2) induces apoptosis in the nontransformed murine fibroblastic NIH3T3 cells. Somatostatin receptor subtype 2 expression induced an executioner caspase-mediated apoptosis through a tyrosine phosphatase SHP-1 (Src homology domain phosphatase-1)-dependent stimulation of nuclear factor kappa B (NF-kappaB) activity and subsequent inhibition of the mitogen-activated protein kinase JNK. Tumor necrosis factor alpha (TNFalpha) stimulated both NF-kappaB and c-Jun NH2-terminal kinase (JNK) activities, which had opposite action on cell survival. Importantly, sst2 sensitized NIH3T3 cells to TNFalpha-induced apoptosis by (1) upregulating TNFalpha receptor protein expression, and sensitizing to TNFalpha-induced caspase-8 activation; (2) enhancing TNFalpha-mediated activation of NF-kappaB, resulting in JNK inhibition and subsequent executioner caspase activation and cell death. We have here unraveled a novel signaling mechanism for a G protein-coupled receptor, which directly triggers apoptosis and crosstalks with a death receptor to enhance death ligand-induced apoptosis.

Physiology of somatostatin receptors

Since its discovery three decades ago as an inhibitor of GH release from the pituitary gland, somatostatin has attracted much attention because of its functional role in the regulation of a wide variety of physiological functions in the brain, pituitary, pancreas, gastrointestinal tract, adrenals, thyroid, kidney and immune system. Its actions include inhibition of endocrine and exocrine secretions, modulation of neurotransmission, motor and cognitive functions, inhibition of intestinal motility, absorption of nutrients and ions and vascular contractility. In addition, the peptide controls the proliferation of normal and tumor cells. Its action is mediated by a family of G protein-coupled receptors [somatostatin receptor (SSTR)1-SSTR5] that are widely distributed in normal and cancer cells. Direct antitumor activities, mediated through SSTR expressed in tumor cells, include blockade of autocrine/paracrine growth-promoting hormone and growth factor production, inhibition of growth factor-mediated mitogenic signals and induction of apoptosis. Indirect antitumor effects include inhibition of growth-promoting hormone and growth factor secretion, and antiangiogenic actions. Many human tumors express more than one SSTR subtype, with SSTR2 being predominant. These receptors represent the molecular basis for the clinical use of somatostatin analogs in the treatment of endocrine tumors and their in vivo localization. This review covers the present knowledge in SSTR biology and signaling.

Sinus CT scans and mediator release in nasal secretions after nasal challenge with cypress pollens

BACKGROUND

Involvement of paranasal sinuses has been suggested in allergic rhinitis but not clearly demonstrated.

AIMS

To investigate the relationship between intermittent allergic rhinitis and computerized tomography (CT).

METHODS

Twenty patients with intermittent rhinitis and sensitized to cypress pollens underwent unilateral nasal provocation tests (NPTs) using increasing concentrations of cypress pollens out of the pollen season. Sinus CT-scans were carried out just before a NPT and 24 h later. Nasal lavage was carried out just before a NPT, 30 min after a positive challenge and again 24 h later. Leucotriene C4/D4, intracellular adhesion molecule-1 and eosinophil cationic protein were measured in nasal secretions.

RESULTS

Thirteen patients (65%) showed an alteration in their CT-scans after allergen challenge. Ten of them showed sinus changes controlateral to their allergenic provocation. Radiological changes mainly affected the osteomeatal complex and the ethmoid sinuses. Pre-existing abnormalities (13 of 20 cases) mainly concerned the maxillary sinuses. There was no correlation between CT-scan abnormalities and levels of mediators released in nasal secretions.

CONCLUSIONS

We have shown that nasal allergen challenge can produce radiological changes in the paranasal sinuses. This mainly concerned the ethmoid sinuses.

Somatostatin receptors and regulation of cell proliferation

Somatostatin is an inhibitory neuropeptide, which acts on various targets throughout the body to regulate a variety of physiological functions including inhibition of endocrine and exocrine secretions, modulation of neurotransmission, motor and cognitive functions, inhibition of intestinal motility, absorption of nutrients and ions, vascular contractility and inhibition of normal and tumour cell proliferation. It exerts its effects through interaction with five somatostatin receptors (sst1-sst5), which belong to the family of G-protein-coupled receptors with seven transmembrane spanning domains and are variably expressed in a variety of tumours such as gastroenteropancreatic tumours, pituitary tumours, and carcinoid tumours. This review covers the present knowledge regarding the molecular mechanisms involved in somatostatin antineoplastic activity. Evidence that sst2 receptor acts as a tumour suppressor is also discussed.

[Value of thoracic CT in the management of severe hemoptysis]

PURPOSE

To assess the value of thoracic CT in the management of patients with severe hemoptysis.

PATIENTS AND METHODS

Between January 1997 and January 2001, 62 patients were investigated for severe hemoptysis (>300 ml/24H). The protocol, performed before angiography and embolization, included bronchial fiberoptic examination (BFE) followed by thoracic spiral CT-angiography. Data recorded at CT and BFE were the presence and location of bleeding, the etiology of hemoptysis and the therapeutic modality.

RESULTS

Nine patients with life-threatening hemoptysis directly underwent bronchial embolization. CT was available in the 53 remaining patients. No abnormality was found in 4 patients. CT assessed the presence (n=49) and the location (n=38) of the bleeding. The etiology was determined in 49 patients. BFE was feasible in 38/53 patients. BFE assessed the presence (n=38) and location (n=15) of the bleeding. The etiology was determined in 12 cases of bronchial tumour. The available findings of CT and BFE for the presence and the location of the bleeding were concordant. Comparing fiberoptic examination and thoracic CT, the percentages of localized bleedings (39% and 72%) and demonstrated etiologies (32% and 92%), were significantly different (p<0,005 and p<0.0001 respectively).

CONCLUSION

Although retrospective and limited by the small number of cases, our study provides arguments to perform thoracic CT before bronchial fiberoptic examination for the management of severe hemoptysis.

[Intracranial primary epidermoid carcinoma]

We report a case of intracranial primitive epidermoid carcinoma localized in the right temporal fossa in a 40-year-old man. The patient was submitted to surgical removal of his tumor and radiotherapy. Unfortunately, the survival time was six weeks after the operation. Clinical, radiological, anatomopathological features and the interest of the radiotherapy are discussed.

Expression and meaning of medical language: building an epistemological framework for the study of semantic distance

The use of language for communication purposes introduces a semantic gap in data processing. We have developed a new tool called semantic distance to overcome this gap. A previous presentation of our tool was based on an empirical approach. Here, we examine the properties and theoretical foundation of semantic distance from a rationalistic perspective. We present an epistemological framework to explain the meaning of semantic distance. As a tool, the purpose of semantic distance is the exchange of data or knowledge based on linguistic expressions between software components. We propose a review of the relationship between language and its representation for data processing based on the underlying philosophical assumptions. Description logic is a new paradigm in the medical informatics community to express relations between terms in "is-a" hierarchies. The utility of semantic distance is compared to description logic for communication purposes in different use cases.

Reversible amiodarone-induced lung disease: HRCT findings

The aim of this study was to describe thoracic high-resolution computed tomography (HRCT) findings of reversible amiodarone-induced lung disease (AILD). The thoracic HRCT of 20 symptomatic patients who were considered as having reversible AILD by the medical staff of our institution were retrospectively reviewed. The patient-selection criteria used were the development of new respiratory symptoms while receiving amiodarone, the exclusion of other respiratory and cardiac diseases, and the decrease of both respiratory symptoms and radiological abnormalities after cessation of amiodarone and corticotherapy. The CT data recorded were those usually sought infiltrative lung diseases. The radiological findings using chest film (n=20) and HRCT (n=4) follow-up was noted. All patients had ground-glass opacities, associated with consolidations (n=4), thin intralobular reticulations (n=5), or both (n=11), with a subpleural (n=18) or central (n=2) location. Eight patients had high-density areas and 13 had pleural thickening (n=13). Bronchial abnormalities included dilation (n=16) and wall thickening (n=19). After therapeutic management, the radiological follow-up showed complete (n=17) or incomplete (n=3) improvement. Ground-glass opacities associated with thin intralobular reticulations and/or subpleural consolidations and bronchial abnormalities are common HRCT findings in reversible AILD.

cAMP neuropeptide agonists induce pituitary suppressor of cytokine signaling-3: novel negative feedback mechanism for corticotroph cytokine action

The hypothalamo-pituitary-adrenal (HPA) axis maintains a homeostatic response to stress, infection, or neoplasia. Inflammatory cytokines, including leukemia inhibitory factor (LIF), stimulate the HPA axis either directly at the pituitary corticotroph, or indirectly through induction of CRH or sympathetic noradrenergic neurons, and mediate the immuno-neuroendocrine interface. Unrestrained HPA axis activation leads, however, to immunosuppression. Because suppressor of cytokine signaling-3 (SOCS-3) is a potent inhibitor of LIF-activated HPA axis, and dynamic interactions between hypothalamus-derived cAMP-inducing neuropeptides and proinflammatory cytokines occur at the corticotroph level, we investigated SOCS-3 expression in response to peptides that stimulate cAMP including CRH, pituitary adenylate cyclase-activating polypeptide, and epinephrine. (Bu)2cAMP mediates induction of SOCS-3 promoter activity (6.7-fold +/- 0.5, P < 0.001) and SOCS-3 gene expression (4-fold +/- 0.8, P < 0.005) in a PKA-dependent manner. LIF and cAMP-inducing agents are additive on SOCS-3 promoter activity (22-fold +/- 2.6, LIF + (Bu)2cAMP vs. 7.3-fold +/- 0.6, LIF alone, P < 0.05) and on SOCS-3 transcription (11.3-fold +/- 2.1, LIF + (Bu)2cAMP vs. 9.3-fold +/- 1, LIF alone, P < 0.05), suggesting alternate pathways for LIF and cAMP-mediated corticotroph signaling. Similarly, LIF and CRH or pituitary adenylate cyclase-activating polypeptide are additive for SOCS-3 promoter activity and transcription (P < 0.05). Whereas signal transducer and activator of transcription 3 binding to the SOCS-3 promoter mediates LIF action, several SOCS-3 promoter regions containing cAMP-responsive elements are required for cAMP-PKA effect. Thus, both classes of POMC-inducing agents, cytokines as well as cAMP-inducing central peptides, regulate SOCS-3, providing a further level of negative HPA axis control during inflammation. These results indicate a sensitive intracellular autoregulation of corticotroph function.

Asymmetric alkene epoxidation with chromium oxo salen complexes. A systematic study of salen ligand substituents

[structure: see text]. In the stoichiometric asymmetric epoxidation of E-beta-methylstyrene with cationic chromium-salen oxo complexes, enantioselectivity is increased by halo-substitution at the 3,3'- and 6,6'-positions and decreased at the 4,4'- and 5,5'-positions on the salen rings. Addition of triphenylphosphine oxide significantly increases selection with 3,3'- or 5,5'-substituents but not with 4,4'- or 6,6'-substituents. Use of nitrate counterion is beneficial in most cases. The results are discussed with respect to the mode of stereoselection in metal-salen epoxidations.

Antiproliferative effect of somatostatin and analogs

Over the past decade, antiproliferative effects of somatostatin and analogs have been reported in many somatostatin receptor-positive normal and tumor cell types. Regarding the molecular mechanisms involved, somatostatin or analogs mediate their action through both indirect and direct effects. Somatostatin acts through five somatostatin receptors (SSTR1-5) which are variably expressed in normal and tumor cells. These receptors regulate a variety of signal transduction pathways including inhibition of adenylate cyclase, regulation of ion channels, regulation of serine/threonine and tyrosine kinases and phosphatases. This review focuses on recent advances in biological mechanisms involved in the antineoplastic activity of somatostatin and analogs.

SOCS proteins: modulators of neuroimmunoendocrine functions. Impact on corticotroph LIF signaling

Several members of the newly characterized family of suppressor of cytokine signaling (SOCS) proteins-such as SOCS-1, SOCS-3, and CIS-act as negative regulators of the cytokine-induced Jak-STAT signaling cascade. The expression of SOCS proteins is stimulated by a variety of cytokines and hormones in a tissue-specific manner. This article reviews our current understanding of SOCS proteins and their role as modulators of neuroimmunoendocrine functions, for example, in signaling of leptin, growth hormone, and prolactin, specially focusing on the impact of SOCS proteins on corticotroph leukemia inhibitory factor (LIF) signaling. LIF, a member of the gp130 sharing cytokine family, modulates pituitary development, POMC gene expression, and ACTH secretion. Current data on the negative autoregulatory function of the suppressor of cytokine signaling, SOCS-3, in LIF-induced POMC gene expression and ACTH secretion are extensively discussed.

Direct regulation of pituitary proopiomelanocortin by STAT3 provides a novel mechanism for immuno-neuroendocrine interfacing

Neuroendocrine ACTH secretion responds to peripheral inflammatory and stress signals. We previously demonstrated that the proinflammatory cytokine, leukemia inhibitory factor (LIF), affects the hypothalamo-pituitary-adrenal axis (HPA) by stimulating in vitro and in vivo pituitary proopiomelanocortin (POMC) gene expression and ACTH secretion and by potentiating the action of hypothalamic corticotropin releasing hormone (CRH). Whereas pathways shown thus far to regulate POMC expression exclusively involve cAMP or calcium, we here describe a direct and indirect STAT3-dependent regulation of POMC transcription by LIF. Using progressive 5'-deletions of POMC promoter, we identified a LIF-responsive -407/-301 region that contains two juxtaposed sequences within -399/-379 related to a STAT3 DNA-binding motif. Each sequence within -399/-379 separately corresponds to a low-affinity and direct binding site for STAT3, but, in combination, these sequences bind STAT3 cooperatively and with high affinity. Moreover, LIF-activated STAT3 indirectly mediates LIF corticotroph action by inducing and potentiating CRH-induced c-fos and JunB expression and binding to the POMC AP-1 element. We therefore conclude that both a direct and indirect route mediate LIF-induced STAT3 activation of POMC transcription. Demonstration of STAT3-dependent regulation of the POMC gene represents a powerful mechanism for immuno-neuroendocrine interfacing and implies a direct stimulation of ACTH secretion by inflammatory and stress-derived STAT3-inducing cytokines.

Radiology on Internet: advice in consulting websites and evaluating their quality

Services offered by Internet are increasing continually and 15,000 medical websites covering all the specialties are available presently. Finding relevant information with a spider-web organization is difficult. We recommend starting with hierarchical lists which propose a selection of sites corresponding to medical specialties. We give our selection of important radiological websites dealing with image databases, case reports, radioanatomy and continuing medical education. While surfing the Web, an evaluation of the quality of websites is necessary. We used quality criteria proposed by Darmoni to rate the quality of ten websites. The global quality is good; help pages and external links are the main noticed shortcomings. All webmasters should pay attention to quality criteria and show visible marks of Darmoni criteria on their home page. To be able to foresee which Internet options should be developed, we evaluated our website and sent a questionnaire to our users. Clinical cases are the most requested facilities; they could be used for continuing medical education.

Signal transduction of somatostatin receptors negatively controlling cell proliferation

Somatostatin acts as an inhibitory peptide of various secretory and proliferative responses. Its effects are mediated by a family of G-protein-coupled receptors (sst1-5) that can couple to diverse signal transduction pathways such as inhibition of adenylate cyclase and guanylate cyclase, modulation of ionic conductance channels, and protein dephosphorylation. The five receptors bind the natural peptide with high affinity but only sst2, sst5 and sst3 bind the short synthetic analogues. Somatostatin negatively regulates the growth of various normal and tumour cells. This effect is mediated indirectly through inhibition of secretion of growth-promoting factors, angiogenesis and modulation of the immune system. Somatostatin can also act directly through sst receptors present on target cells. The five receptors are expressed in various normal and tumour cells, the expression of each receptor being receptor subtype and cell type specific. According to the receptor subtypes, distinct signal transduction pathways are involved in the antiproliferative action of somatostatin. Sst1, 4 and 5 modulate the MAP kinase pathway and induce G1 cell cycle arrest. Sst3 and sst2 promote apoptosis by p53-dependent and -independent mechanisms, respectively.

[Interventional radiology of the thorax]

Interventional radiology of the thorax includes a wide variety of diagnostic and/or therapeutic procedures. Transthoracic needle biopsy is a widely used technique. Generall, computed tomography is used to guide the puncture, less commonly fluoroscopy or in exceptional cases ultrasound. Targets include parenchymatous, pleural and mediastinal lesions. The biopsy specimen is used for cytology, histology, bacteriology, mycology and parasitology studies. Needle biopsy is also the first step in more complex procedures: drainage of thoracic collections, inserting harpoons, thoracic sympatholysis, palliative treatment of aspergillomas. Bronchial arteriography with embolization is an effective emergency symptomatic treatment for severe hemoptysis. Endovascular vaso-occlusion procedures can be used for rare arteriovenous pulmonary fistulas. Superior vena cava obstruction can be treated, usually in a palliative procedure, by installing an endovascular endoprosthesis.

Using semantic distance for the efficient coding of medical concepts

OBJECTIVE

To use the notion of semantic distance to find the nearest neighbors of a medical concept in a controlled vocabulary.

MATERIAL AND METHOD

392 concepts from the cardiovascular chapter of the ICD-10 were projected on the axes of SNOMED III. Distances were measured on each axis and the resulting distance was found using a Lp norm.

RESULTS

The distance between a set of ischemic diseases and a set of non-ischemic diseases was significant (p < 0.0001). Our method was validated by finding the k nearest neighbors of ten different diagnoses from the ICD-10 cardiovascular chapter.

DISCUSSION

The availability of SNOMED-RT should improve our method. Several more steps are necessary to provide an ideal coding tool.

Acute murine cytomegalovirus infection: a model for determining antiviral activity against CMV induced hepatitis

Acute intraperitoneal infection of weanling BALB/c mice with murine cytomegalovirus (MCMV) resulted in an inoculum titer-dependent weight loss, mortality and elevation of plasma transaminases (ALT: alanine transaminase and AST: aspartate transaminase). Three days post infection (p.i.) with 10(4.85) plaque forming units (pfu) there was 90% mortality with a mean death day p.i. of 4.1 +/- 0.2. Plasma levels of ALT and AST were elevated 24- and 15-fold, respectively. Organ titers of virus (log10 pfu/g tissue) were 6.16 in the liver, 6.05 in the spleen, 4.0-4.7 in the lung, heart, kidney and intestine and undetectable in the muscle and brain. Organ concentrations (units/g wet-weight) of ALT were highest in the liver, whilst for AST the highest levels were found in the heart. The concentrations of ALT but not AST were reduced (35-55%) in the infected liver; the concentrations of ALT and AST were not changed in other infected organs. There were excellent correlations (r > 0.95) between viral titers in the liver, increases of plasma ALT and depletion of liver ALT. HPMPC and ganciclovir administered either p.o. or s.c. reduced mortality, increases in plasma transaminases and viral burdens in the liver and prevented depletion of liver ALT. HPMPC was approximately 10-fold more potent than ganciclovir. These results strongly suggest that intraperitoneal infection of the BALB/c mouse with MCMV represents an animal model of CMV hepatitis that can be monitored by measuring plasma ALT.

[Web radiology servers: advices for users, their development and evaluation of the quality of sites]

Sites available on the Internet are constantly increasing and over 15,000 medical websites covering all medical sub-specialties are now available. Finding relevant information on the web may be time consuming and difficult. We suggest that new users begin by accessing servers where lists of available sites are grouped under headings such as medical sub-specialties. We will list a selection of useful radiological websites providing image databases, case reports, radiological anatomy and continuing medical education. While surfing on the web, an evaluation of the quality of the websites is necessary. We used the quality criteria proposed by Darmoni to rate the quality of ten websites. The overall quality was good, but the lack of help options and external links were the main pitfalls that we noted. All webmasters should pay attention to quality criteria and show the Darmoni criteria on their homepage. In order to evaluate which internet options should be developed, we evaluated our own website and submitted a questionnaire to our users. Clinical cases were the most requested feature, they could be used for continuing medical education.

Inhibitory roles for SHP-1 and SOCS-3 following pituitary proopiomelanocortin induction by leukemia inhibitory factor

Leukemia inhibitory factor (LIF) is a pleiotropic cytokine that stimulates the hypothalamo-pituitary-adrenal (HPA) axis through JAK-STAT activation. We show here that LIF-induced JAK2 and STAT3 tyrosine phosphorylation is transient, disappearing within 20 and 40 minutes, respectively. LIF activates the SH2 domain-containing tyrosine phosphatase, SHP-1, with maximal stimulation observed at 30 minutes. SHP-1 is constitutively associated with JAK2, and LIF induces recruitment of phosphorylated STAT3 to this complex. Overexpression of wild-type or dominant negative forms of SHP-1 shows decreased or increased LIF-induced proopiomelanocortin (POMC) promoter activity, respectively. LIF-induced JAK2 and STAT3 dephosphorylation is delayed until after 60 minutes in cells that overexpress the mutant SHP-1. In addition, SOCS-3, a negative regulator of LIF signaling, binds to JAK2 after 60 minutes of LIF stimulation, after which the complex is degraded by the proteasome. SOCS-3 overexpression blocks LIF-induced JAK2 tyrosine phosphorylation, confirming a role for SOCS-3 in deactivating JAK2 by direct association. Using SOCS-3 fusion proteins, we also define regions of the SOCS-3 protein that are critical for inhibition of LIF-induced POMC promoter activity. Corticotrophic signaling by LIF is thus subject to 2 forms of negative autoregulation: dephosphorylation of JAK2 and STAT3 by the SHP-1 tyrosine phosphatase, and SOCS-3-dependent inactivation of JAK2.

[Embolization treatment of a traumatic adrenal hemorrhage]

We report a case of adrenal hemorrhage in a blunt abdominal trauma after a motor vehicle crash. The patient was treated by a percutaneous embolization without any complication.

Autoregulation of pituitary corticotroph SOCS-3 expression: characterization of the murine SOCS-3 promoter

Pituitary corticotroph SOCS-3 is a novel intracellular regulator of leukemia inhibitory factor (LIF)-mediated proopiomelanocortin gene expression and adrenocorticotropic hormone (ACTH) secretion, inhibiting LIF-activated Janus kinase-signal transducers and activators of transcription (STAT) signaling in a negative autoregulatory loop. We now demonstrate in corticotroph AtT-20 cells that LIF-stimulated endogenous SOCS-3 mRNA expression is blocked in stable transfectants of SOCS-3 wild type or in dominant negative STAT-3 mutants, respectively. We characterized approximately 3.8-kb genomic 5' sequence of murine SOCS-3, including approximately 2.9-kb sequence upstream of the transcription start site (+1), which was determined by 5' rapid amplification of cDNA ends and RNase protection assay. Different 5' constructs were cloned into the pGL3Basic vector, and luciferase activity was assayed in transiently transfected ACTH-secreting corticotroph AtT-20 cells. A STAT-1/STAT-3 binding element, located at nucleotides -72 to -64, was essential for LIF stimulation of SOCS-3 promoter activity. LIF induced 10-fold increased luciferase activity in a wild-type construct spanning -2757 to +929 bases. However, deletion or point mutation of the STAT-1/STAT-3 binding element abrogated LIF action (2- to 3-fold). Electrophoretic mobility-shift assay analysis confirmed specific binding of STAT-1 and STAT-3 to this region. These results characterize the genomic 5' region of murine SOCS-3 and identify an important STAT-1/STAT-3 binding element therein. Thus, LIF-stimulated SOCS-3 gene expression is at least in part mediated by STAT-3 and STAT-1. The cytokine inhibitor SOCS-3 acts in a negative loop to autoregulate its own gene expression, thus limiting its accumulation in the corticotroph cell. These results demonstrate a mechanism for corticotroph plasticity with rapid "on" and "off" ACTH induction in response to neuro-immuno-endocrine stimuli, such as LIF.

Bronchial aneurysms mimicking aortic aneurysms: endovascular treatment in two patients

Bronchial artery dilatation and aneurysm formation is a potential complication of local inflammation, especially in bronchiectasis. When the bronchial artery has an ectopic origin from the inferior segment of the aortic arch, aneurysms may mimick aortic aneurysms. Despite this particular location, endovascular treatment is possible. We report two such aneurysms that were successfully embolized with steel coils.

Critical role for STAT3 in murine pituitary adrenocorticotropin hormone leukemia inhibitory factor signaling

Leukemia inhibitory factor (LIF) is a pleiotropic neuroimmune cytokine that promotes corticotroph cell differentiation and induces proopiomelanocortin (POMC) mRNA expression and adrenocorticotropin hormone (ACTH) secretion. However, molecular mechanisms for this induction remain elusive. We therefore developed ACTH-secreting AtT20 transformants for wild-type or mutated STAT3, a cytokine signaling molecule, to address whether STAT3 is a determinant of LIF-mediated ACTH regulation. We show that these mutants act in a dominant negative manner by blocking endogenous STAT3 tyrosine phosphorylation or STAT3 DNA binding. Attenuation of STAT3 activity in the dominant negative AtT20 clones prevented LIF from promoting transcriptional activation of the POMC promoter (2.1-fold), whereas this LIF action was enhanced (7.7-fold; p < 0.05) in wild-type STAT3-overexpressing clones in comparison to mock-transfected cells (4.5-fold). However, wild-type or dominant negative STAT3-overexpressing clones showed comparable (4-fold) POMC induction after treatment with cyclic adenosine monophosphate (cAMP), an alternate inducer of POMC transcription, indicating the STAT3 specificity for LIF signaling. Moreover, dominant negative inactivation of STAT3 activity resulted in abrogation of LIF-induced POMC mRNA levels and ACTH secretion, confirming the in vivo role of STAT3 in LIF-mediated corticotroph action. Chemical or molecular blockade of the mitogen-activated protein kinase pathway did not affect LIF-mediated corticotroph function. These results indicate that STAT3 is a critical intrapituitary component of the LIF-mediated neuroimmunoendocrine interface in corticotroph cells.

[Contribution of high-resolution volume computed tomography (HRVCT) for the exploration of diffuse pulmonary infiltrative disorders]

AIM

To assess high-resolution volume computed tomography (HRVCT) for the investigation of diffuse pulmonary infiltrative disorders.

PATIENTS AND METHODS

Thirty patients with diffuse interstitial disease (idiopathic fibrosis n = 7, silicosis n = 4, asbestosis n = 5, sarcoidosis n = 7, histiocytosis n = 2, lymphangitis carcinomatosa n = 2, tuberculosis n = 1, bronchiolitis obliterans n = 1) were explored using high-resolution computed tomography (HRCT) and HRVCT. All diagnoses were proven by fiberscopy, bronchoalveolar lavage and respiratory function tests and/or lung biopsy. The HRVCT protocol consisted of spiral tomography using 10 mm slices. Data were processed with a Windows Advantage workstation (GE Milwaukee). Two readers compared multiprojection volume reconstruction (MPVR) using maximal intensity projection (MIP) and minimal intensity projection (MINIP) displays with millimetric HRCT slices acquired at the same volume.

RESULTS

Micronodules were detected better with HRVCT than with HRCT. MIP mode enabled better distinction between nodules and vessels. MINIP mode enabled better detection of cysts in the pulmonary parenchyma than HRCT. The honeycomb aspect of pulmonary fibrosis was differentiated better than super-infected central-lobar emphysema. MINIP mode enabled detection of ground glass opacities which were not visible on HRCT. Certain anomalies were however detected only on HRCT. HRVCT was very sensitive to movement effects which altered image quality, particularly in the MINIP mode.

CONCLUSION

HRVCT is a new and promising approach for investigating diffuse pulmonary infiltrative disorders.

[Cervical epidural injection technic under computed tomography guidance in the treatment of cervicobrachial neuralgia]

Epidural injections of corticosteroids in the cervical spine can provide effective treatment of cervicobrachial neuralgia. This technique is mainly described by anesthesiologists who perform injections without imaging control. We demonstrate that this infiltration can be easily performed under CT-guidance by radiologists.

Dose and duration-dependence of ganciclovir treatment against murine cytomegalovirus infection in severe combined immunodeficient mice

The present study investigates the full dose-response curve and treatment duration dependence of ganciclovir (GCV) against murine cytomegalovirus (MCMV) infection in severe combined immunodeficiency (SCID) mice. Animals inoculated intraperitoneally with 6.3 x 10(3) pfu of MCMV per mouse developed typical wasting syndrome rapidly and died around day 12 post-inoculation. Once-daily treatment with subcutaneous GCV for 5 days dose dependently delayed MCMV-induced wasting syndrome and mortality at a dose range of 1-80 mg/kg per day, whereas a dose of 160 mg/kg per day induced reversible side-effects. The effect of GCV treatment on mean death day (MDD) was significantly correlated to reductions of viral titers in the lung (r = 0.969, P < 0.05). Treatment duration dependence was examined at the dose of GCV at 80 mg/kg per day for 1, 5, 8 and 12 days. The protective duration, over vehicle-treated mice, was constantly 3-4 days plus the duration of GCV treatment, as evidenced by the delay of viral replication, wasting syndrome and death. At a sub-optimally effective dose of 10 mg/kg per day of GCV, maximum protection was achieved with a 8-day treatment regimen. Prolongation of this treatment to 12 days failed to further delay mean death day and wasting syndrome that started on day 10, indicative of insufficient suppression of viral replication. Treatment with a single dose of GCV failed to show a complete dose-response curve since only minimal protective effects were observed at the dose of 80 mg/kg while side-effects were associated with the dose of 160 mg/kg. The treatment duration dependence and requirement for sufficient dosage of GCV against CMV infection observed in the current model are consistent with clinical observations. It also suggests that 5 8 days treatment duration may be a good balance considering the opportunity for identifying active compounds and speeding up the turnaround time in drug evaluations.

Pituitary corticotroph SOCS-3: novel intracellular regulation of leukemia-inhibitory factor-mediated proopiomelanocortin gene expression and adrenocorticotropin secretion

As pituitary leukemia-inhibitory factor (LIF) mediates neuroimmune signals to the hypothalamo-pituitary-adrenal axis, we tested the role of intracellular SOCS-3 in corticotroph function. SOCS-3, a cytokine-inducible protein of the suppressor of cytokine signaling (SOCS) family, is expressed in the murine pituitary in vivo. After i.p. injection of LIF (5.0 micrograms/mouse) or interleukin-1 beta (0.1 microgram/mouse) pituitary SOCS-3 mRNA was stimulated 9-fold and 6-fold, respectively. Also, in corticotroph AtT-20 cells LIF and interleukin-1 beta both potently stimulated SOCS-3 mRNA expression. In AtT-20 cells, stable overexpression of SOCS-3 inhibits basal and LIF-stimulated ACTH secretion in comparison to mock-transfected AtT-20 cells (basal: 4426 +/- 118 vs. 4973 +/- 138 pg/ml, P < 0.05; LIF-induced: 5511 +/- 172 vs. 9308 +/- 465 pg/ml, P < 0.001). Stable overexpression of SOCS-3 cDNA in AtT-20 cells also resulted in a significant 50% decrease of LIF-induced POMC mRNA levels (P < 0.05) and POMC promoter activity (P < 0.001), respectively. Western blot analysis revealed an inhibition of LIF-stimulated gp130 and STAT-3 phosphorylation in SOCS-3 overexpressing AtT-20 cells. Thus, SOCS-3 inhibits the Janus kinase (JAK) and signal transducers and activators of transcription (STAT) pathway, which is known to mediate LIF-stimulated ACTH secretion and POMC gene expression. In conclusion, SOCS-3 functions as an intracellular regulator of POMC gene expression and ACTH secretion, acting as a negative feedback mediator of the cytokine-mediated neuro-immuno-endocrine interface.

sst2 somatostatin receptor mediates negative regulation of insulin receptor signaling through the tyrosine phosphatase SHP-1

We have previously reported in Chinese hamster ovary (CHO) cells expressing sst2 that activation of the sst2 somatostatin receptor inhibits insulin-induced cell proliferation by a mechanism involving stimulation of a tyrosine phosphatase activity. Here we show that the tyrosine phosphatase SHP-1 was associated with the insulin receptor (IR) at the basal level. Activation of IR by insulin resulted in a rapid and transient increase of tyrosine phosphorylation of IR, its substrates IRS-1 and Shc, and also of SHP-1. This was then followed by a rapid dephosphorylation of these molecules, which was related to the insulin-induced increase of SHP-1 association to IR and of SHP-1 activity. On the other hand, addition to insulin of the somatostatin analogue, RC160, resulted in a higher and faster increase of SHP-1 association to IR directly correlated with an inhibition of phosphorylation of IR and its substrates, IRS-1 and Shc. RC160 also induced a higher and more sustained increase in SHP-1 activity. Furthermore, RC160 completely suppressed the effect of insulin on SHP-1 phosphorylation. Finally, in CHO cells coexpressing sst2 and a catalytically inactive mutant SHP-1, insulin as well as RC160 could no longer stimulate SHP-1 activity. Overexpression of the SHP-1 mutant prevented the insulin-induced signaling to be terminated by dephosphorylation of IR, suppressed the inhibitory effect of RC160 on insulin-induced IR phosphorylation, and abolished the cell proliferation modulation by insulin and RC160. Our results suggest that SHP-1 plays a role in negatively modulating insulin signaling by association with IR. Furthermore, somatostatin inhibits the insulin-induced mitogenic signal by accelerating and amplifying the effect of SHP-1 on the termination of the insulin signaling pathway.

Acute myeloid leukemia cells with low P-glycoprotein expression and high rhodamine 123 efflux capacity display high clonogenicity

This study was designed to correlate the clonogenic capacity of acute myeloid leukemia (AML) cells with P-glycoprotein (P-gp) expression level and P-gp-mediated efflux capacity. Fifty AML cell samples were tested for P-gp expression using MRK16 monoclonal antibody and flow cytometry. Among them, 12 samples were selected for sorting experiments according to the following two criteria: their clonogenic capacity in methylcellulose in the presence of 5637 conditioned medium, and the heterogeneity of P-gp distribution in leukemic cells. For each of these 12 samples, leukemic cells which displayed the highest P-gp expression level (P-gp++) and P-gp- leukemic cells were sorted after MRK16 staining and seeded into methylcellulose for primary clonogenic assay. In each case, the number of CFU-L in the P-gp fraction was significantly higher than that of the P-gp++ fraction (P < 0.01); the median number of CFU-L for 10(5) seeded cells being 147 (range 3-1855) and 495 (range 60-4100) for P-gp++ and P-gp- populations, respectively. Furthermore, in order to correlate clonogenic capacity and P-gp function, AML cells were stained with rhodamine 123 (Rh 123), washed and then sorted after 4 h incubation at 37 degrees C in Rh 123-free media on the basis of their residual fluorescence intensity before plating. For each of six samples, we found that the number of CFU-L in the AML cell fraction which displayed the most efficient Rh 123 efflux capacity (Rh 123dull) was significantly higher compared to that of the AML cell fraction which displayed high residual fluorescence signal (Rh 123bright) (P = 0.05); the median number of CFU-L for 10(5) seeded cells being 1025 (range 250-2240) and 296 (range 11-838) for Rh 123dull and Rh 123bright populations, respectively. Altogether this study suggests that, for an individual AML cell population, the clonogenic fraction is preferentially recruited in AML cells which display low P-gp expression and high P-gp-mediated efflux capacity.