Synaptic communication mediates the assembly of a self-organizing circuit that controls reproduction.

Migration of gonadotropin-releasing hormone (GnRH) neurons from their birthplace in the nasal placode to their hypothalamic destination is critical for vertebrate reproduction and species persistence. While their migration mode as individual GnRH neurons has been extensively studied, the role of GnRH-GnRH cell communication during migration remains largely unexplored. Here, we show in awake zebrafish larvae that migrating GnRH neurons pause at the nasal-forebrain junction and form clusters that act as interhemisphere neuronal ensembles. Within the ensembles, GnRH neurons create an isolated, spontaneously active circuit that is internally wired through monosynaptic glutamatergic synapses into which newborn GnRH neurons integrate before entering the brain. This initial phase of integration drives a phenotypic switch, which is essential for GnRH neurons to properly migrate toward their hypothalamic destination. Together, these experiments reveal a critical step for reproduction, which depends on synaptic communication between migrating GnRH neurons.

S100A7: from mechanism to cancer therapy.

Within the tumor, malignant and stromal cells support each other by secreting a wide variety of growth factors and cytokines, allowing tumor growth and disease progression. The identification and regulation of those key factors in this crosstalk has opened the opportunity to develop new therapeutic strategies that not only act on the tumor cells but also on the stroma. Among these factors, S100A7 protein has gained interest in the last years. With key roles in cell motility its expression correlates with increased tumor growth, angiogenesis and metastatic potential. This work aims to deepen in the role played by extracellular S100A7 in the tumor microenvironment, offering a new integrative insight of its mechanism of action on each cellular compartment (tumor, endothelial, immune and fibroblast). As a result, we demonstrate its implication in cell migration and invasion, and its important contribution to the formation of a proinflammatory and proangiogenic environment that favors tumor progression and metastasis. Furthermore, we define its possible role in the pre-metastatic niche formation. Considering the relevance of S100A7 in cancer progression, we have developed neutralizing monoclonal antibodies, reporting for the first time the proof of principle of this promising therapeutic strategy for cancer treatment.

Assessment of Mycoplasma hyopneumoniae-induced Pneumonia using Different Lung Lesion Scoring Systems: a Comparative Review.

Mycoplasma hyopneumoniae is the primary aetiological agent of swine enzootic pneumonia (EP) and one of the major contributors to the porcine respiratory disease complex (PRDC). Gross lung lesions in pigs affected by EP consist of cranioventral pulmonary consolidation (CVPC), usually distributed bilaterally in the apical, intermediate, accessory and cranial parts of the diaphragmatic lobes. Several lung scoring methods are currently in place for the evaluation of CVPC. The aims of this study were (1) to review the lung lesion scoring systems used to assess pneumonia associated with M. hyopneumoniae infection, and (2) to evaluate eight of these scoring systems by applying them to the lungs of 76 pigs with experimentally-induced M. hyopneumoniae pneumonia. A significant correlation between all lung lesion scoring systems was observed and the coefficients of determination in a regression analysis were very high between each pair-wise comparison, except for a unique scoring system based on image analysis. A formula of equivalence between lung scoring methods was developed in order to compare the results obtained with these methods. The present review provides a basis for comparison (even retrospectively) of lesions evaluated using different lung scoring systems.

S100P antibody-mediated therapy as a new promising strategy for the treatment of pancreatic cancer.

Despite progresses in diagnosis and treatment, pancreatic cancer continues to have the worst prognosis of all solid malignant tumors. Recent evidences suggest that the metastasis-promoting protein S100P stimulates pancreatic tumor proliferation, survival, invasion and metastasis progression through extracellular functions. Moreover, its expression is strongly correlated with poor prognosis in patients with several types of cancer although the entire molecular mechanism responsible for the diverse biological functions is not fully understood. We showed that extracellular S100P stimulates pancreatic carcinoma BxPC3 cell line by promoting cell proliferation. We also demonstrated that S100P induces, in this cell line, the phosphorylation of IκBα and the secretion of matrix metalloproteinase 9 (MMP-9). In addition, treatment with S100P protected cells from injuries induced by the cytotoxic agent Gemcitabine. On the basis of these results, we developed function-blocking anti-S100P monoclonal antibodies (mAbs) that abolished all of its in vitro activities. Furthermore, in vivo treatment with the candidate 2H8 antibody decreased tumor growth and liver metastasis formation in a subcutaneous and orthotopic BxPC3 tumor model. We conclude here that a therapeutic strategy blocking the extracellular activity of S100P by means of specific mAbs could be an attractive therapeutic approach as a single agent or in combination with target-directed or chemotherapeutic drugs to treat pancreatic cancer.

Oleate prevents saturated-fatty-acid-induced ER stress, inflammation and insulin resistance in skeletal muscle cells through an AMPK-dependent mechanism.

AIMS/HYPOTHESIS: Although the substitution of saturated fatty acids with oleate has been recommended in the management of type 2 diabetes mellitus, the mechanisms by which oleate improves insulin resistance in skeletal muscle cells are not completely known. Here, we examined whether oleate, through activation of AMP-activated protein kinase (AMPK), prevented palmitate-induced endoplasmic reticulum (ER) stress, which is involved in the link between lipid-induced inflammation and insulin resistance. METHODS: Studies were conducted in mouse C2C12 myotubes and in the human myogenic cell line LHCN-M2. To analyse the involvement of AMPK, activators and inhibitors of this kinase and overexpression of a dominant negative AMPK construct (K45R) were used. RESULTS: Palmitate increased the levels of ER stress markers, whereas oleate did not. In palmitate-exposed cells incubated with a lower concentration of oleate, the effects of palmitate were prevented. The induction of ER stress markers by palmitate was prevented by the presence of the AMPK activators AICAR and A-769662. Moreover, the ability of oleate to prevent palmitate-induced ER stress and inflammation (nuclear factor-kappa B [NF-κB] DNA-binding activity and expression and secretion of IL6) as well as insulin-stimulated Akt phosphorylation and 2-deoxyglucose uptake was reversed in the presence of the AMPK inhibitor compound C or by overexpression of a dominant negative AMPK construct. Finally, palmitate reduced phospho-AMPK levels, whereas this was not observed in oleate-exposed cells or in palmitate-exposed cells supplemented with oleate. CONCLUSIONS/INTERPRETATION: Overall, these findings indicate that oleate prevents ER stress, inflammation and insulin resistance in palmitate-exposed skeletal muscle cells by activating AMPK.

[Value of brain perfusion SPECT in the follow-up of patients surgically treated for chronic adult hydrocephalus syndrome]. / Valor del SPECT de perfusión cerebral en el seguimiento del tratamiento quirúrgico de pacientes con hidrocefalia crónica del adulto.

OBJECTIVE: The aim of this study was to characterize regional cerebral blood flow in patients with Adult Hydrocephalus Syndrome (AHS) and to evaluate the changes in brain perfusion after surgical derivation treatment. PATIENTS AND METHODS: 20 patients with AHS (age: 72 +/- 14, 12 men) were studied before and six months after surgery. All patients underwent a brain perfusion SPECT (99mTc-HMPAO) prior to surgery and at 6 months post-surgery. Semi-quantitative analysis was done for brain uptake: 0=Normal, 1=Mild, 2=Moderate, 3= Severe, 4=No uptake. The severity of ventricular dilatation was assessed by classifying the intensity and extension of subcortical defects: 0=Normal, 1=Mild, 2=Moderate, 3=Severe. The scores of the pre- and post-surgical studies were compared using the Student-t test. RESULTS: A global reduction of brain uptake was observed (mean score 12.85), mainly in frontal, parietal and temporal lobes, with a significant improvement in post surgical studies (mean score 6, p<0,001). After surgery, 16 (80%) of the 20 patients improved brain uptake. In relationship to subcortical uptake, 5 patients showed mild defects, 9 moderate defects and 6 patients presented severe uptake reduction. In post-surgical studies 15 (75%) patients improved almost one degree in the subcortical score and 65% of the patients showed a normal or mild subcortical uptake reduction. CONCLUSIONS: Brain perfusion SPECT is useful in patients with AHS, detecting brain perfusion defects and evaluating cerebral blood flow improvement after shunt operation.

Valor del SPECT de perfusión cerebral en el seguimiento del tratamiento quirúrgico de pacientes con hidrocefalia crónica del adulto / Brain perfusion spect in patients with chronic adult hydrocephalus syndrome. Pre- and post-surgical study

Objetivo: Evaluar el estado de la perfusión cerebral en pacientes con hidrocefalia crónica del adulto (HCA) y los cambios producidos en la misma tras la derivación de líquido cefalorraquideo (LCR).Material y métodos: Se han evaluado 20 pacientes diagnosticados de HCA (edad: 72 ñ 14; 12 hombres) tratados quirúrgicamente. A todos los pacientes se les realizó un SPECT de perfusión cerebral (99mTc-HMPAO) pre-operatorio y a los 6 meses de la intervención quirúrgica. Se realizó un análisis semicuantitativo del grado de captación en las diferentes regiones cerebrales: 0 = normal; 1 = leve; 2 = moderado; 3 = severo; 4 = ausencia de captación. La hipoactividad subcortical secundaria a la dilatación ventricular se cuantificó en cuatro grados: 0 = normal; 1 = leve; 2 = moderado; 3 = severo. Se compararon los valores obtenidos en el primer y segundo estudio (t-Student).Resultados: Se observó una reducción global de la captación en prácticamente todos los lóbulos (puntuación media 12,85), predominantemente en los lóbulos frontal, temporal y parietal, que mejoró significativamente de forma global y para cada uno de los territorios analizados en el estudio postoperatorio (puntuación media 6, p < 0,001). De los 20 pacientes estudiados 16 (80 por ciento) mejoraron la captación cortical y 4 no presentaron cambios. Respecto a la hipoactividad subcortical, 5 pacientes presentaron un grado leve, 9 presentaban grado moderado y 6 un grado severo. En el estudio postoperatorio 15 (75 por ciento) pacientes mejoraron al menos un grado de captación y un 65 por ciento pasaron a un grado normal o leve de dilatación. Conclusiones: El SPECT de perfusión cerebral es una técnica que permite valorar las alteraciones de la perfusión ocasionadas por la HCA y objetivar la recuperación que produce la implantación de una derivación de LCR (AU)

Comparison of two nimodipine formulations in healthy volunteers.

The objective of this study was to assess the pharmacokientic parameters of regular nimodipine (Bayer), 30 mg, given every 6 h and nimodipine AP (nimodipine in micro particles with programmed action contained in tablets, developed by Biocontrolled-Leti Group Laboratories), 120 mg, given every 24 h. Subjects (19 healthy volunteers, five female; 14 male: age: 21 +/- 0.7 years) received one formulation over 5 days. Then, after a washout period of 7 days, the other formulation was given. The analyst was blinded to the relationship in formulation received. Antecubital blood samples were taken before the first tablet was taken and after 15, 45, 60 min and 2, 4, 6, 8, 12, 13, 18 and 24 h on day 1 and five of each formulation. Nimodipine blood levels were analysed by HPLC. At steady-state regular nimodipine reached a C-max of 10.208 +/- 0.317 ng/ml, at a t-max of 1 h; minimum concentration 6 h after dosage was 1.2929 +/- 0.411 ng/ml, half-life was estimated in 2.9 h. Meanwhile nimodipine AP 120 mg reach a C-max of 11.885 +/- 0.403 ng/ml; a t-max of 1 h with a minimum concentration 24 h after the last dose of 4.2387 +/- 0.353 ng/ml (P < 0.001). Apparent half-life was calculated in 17.8 h (P < 0.001). Area under the curve for the 24 h period was 143.76 ng/ml/min for regular nimodipine and 183.7 ng/ml/min for nimodipine AP 120 mg (P < 0.001), indicating better bioavailability. In conclusion nimodipine in AP formulation 120 mg produced similar peak plasma levels (C-max) than regular nimodipine, but with higher trough (C-min) values and stable plasma levels with one administration every 24 h. This formulation would be more suitable when nimodipine chronic therapy is indicated.

[Quantification of myocardial ischemia in regions dependent on occluded coronary arteries in patients without previous infarction]. / Cuantificación de la isquemia miocárdica en regiones dependientes de arterias coronarias ocluidas de pacientes sin infarto previo.

INTRODUCTION AND OBJECTIVES: The aim of this study is to assess myocardial ischemia in regions with no infarction dependent occluded coronary arteries. PATIENTS AND METHODS: 149 patients with proved coronary artery disease and without previous myocardial infarction were studied by 99mTc-MIBI SPECT (long protocol) and coronary angiography. The extent of the uptake reversibility was quantified in 3 regions (antero-septal, inferior and lateral) of the polar maps, assessing the percentage of each region that had a > 10% difference resulting from the rest uptake minus the stress uptake. The regions dependent on one occluded artery were compared to those dependent on non-occluded arteries. In the regions dependent on one occluded artery a comparison was also made between those which had a good collateral circulation and those which did not. RESULTS: Fifty-four out of 149 patients (36%) had at least one occluded coronary artery (20 anterior descending, 22 right and 27 circumflex coronary arteries). In the visual analysis, reversible defects were observed in all patients with occlusion of the anterior descending and the right coronary artery, but only in half of the occlusions of the circumflex coronary artery. The extent of this reversibility was significantly higher in the regions dependent on occluded arteries and was highly variable, though lower when good collateral circulation was present. CONCLUSIONS: Reversible defects were always observed in the occlusions of the left anterior descending and right coronary arteries, but only in half of those of the circumflex artery. The extent of the ischemia was higher in the regions dependent on one occluded coronary artery, mainly when there was an absence of good collateral circulation.

Expression of death-related genes and their relationship to loss of apoptosis in T1 ductal breast carcinomas.

Expression of the death-related proteins (DRPs) Bcl-2, Bax, Bcl-x and Bak that regulate cell survival and death was examined using immuno-histochemical methods in a group of 142 T1 (<2 cm) ductal breast carcinomas. Immunostaining results were correlated with loss of apoptosis and clinicopathological parameters such as histological grade (HG) and lymph node involvement. Expression of anti-apoptotic proteins Bcl-2 and Bcl-x was found in 57.0% and 62.75% of tumors, respectively. Bcl-2 expression, but not Bcl-x expression, was related to loss of apoptosis. Expression of the apoptotic proteins Bax and Bak was present in 58% of Bcl-2-negative tumors and associated significantly with an increase in apoptosis. Expression of these DRPs was associated significantly with the HG of the tumors: Bcl-2 and Bak expression was predominant in HG I/II tumors, whereas expression of Bcl-xL and Bax was commonly observed in HG III tumors, as occurs for p53 over-expression. Our results suggest that the loss or gain of apoptosis is regulated tightly in T1 breast carcinomas through the expression of different effectors along with tumor cell differentiation.

Treatment of acute myocardial infarction with recombinant tissue-type plasminogen activator.

In Ireland, to date, coronary thrombolytic therapy has been confined almost exclusively to the use of streptokinase. However, a large body of evidence suggests that, in comparison to streptokinase, the agent recombinant tissue-type plasminogen activator (rt-PA) may be more effective in lysing coronary thrombi and achieving coronary reperfusion and causes fewer disturbances of the coagulation system. With these considerations in mind, we undertook a study to explore the future potential role of rt-PA in our particular clinical practice. Sixteen patients presenting to our centre with clinical and ECG features suggestive of acute myocardial infarction were treated with rt-PA and heparin infusion within 3.8 +/- 1.3 (mean +/- SD) [range 0.6 - 5.3] hours of the onset of their symptoms. Reperfusion, as assessed by clinical, electrocardiographic and biochemical criteria, was achieved in 15 of these 16 patients. One patient developed reocclusion that was successfully treated with repeat thrombolytic therapy. Follow up coronary angiography, performed in eight patients, confirmed successful reperfusion in seven. One patient developed an intracranial haemorrhage. The result of this pilot study highlight the importance of considering thrombolytic therapy in all patients presenting with suspected acute myocardial infarction (AMI). Our observations also suggest that rt-PA is very effective in restoring myocardial perfusion in patients with AMI who present at an early stage. As with all thrombolytic agents, it may be associated with haemorrhagic complications. Determination of the precise role of rt-PA, as opposed to other thrombolytic agents, awaits the results of ongoing clinical trials.