Innovative minimally invasive options to treat drug-resistant epilepsies.

Despite the regular discovery of new molecules, one-third of epileptic patients are resistant to antiepileptic drugs. Only a few can benefit from resective surgery, the current gold standard. Although effective in 50-70% of cases, this therapy remains risky, costly, and can be associated with long-term cognitive or neurological side effects. In addition, patients are increasingly reluctant to have a craniotomy, emphasizing the need for new less invasive therapies for focal drug-resistant epilepsies. Here, we review different minimally invasive approaches already in use in the clinic or under preclinical development to treat drug-resistant epilepsies. Localized thermolesion of the epileptogenic zone has been developed in the clinic using high-frequency thermo-coagulations or magnetic resonance imaging-guided laser or ultrasounds. Although less invasive, they have not yet significantly improved the outcomes when compared with resective surgery. Radiosurgery techniques have been used in the clinic for the last 20years and have proven efficiency. However, their efficacy is not better than resective surgery, and various side effects have been reported as well as the potential risk of sudden unexpected death associated with epilepsy. Recently, a new strategy of radiosurgery has emerged using synchrotron-generated X-ray microbeams: microbeam radiation therapy (MRT). The low divergence and high-flux of the synchrotron beams and the unique tolerance to MRT by healthy brain tissues, allows a precise targeting of specific brain regions with minimal invasiveness and limited behavioral or functional consequences in animals. Antiepileptic effects over several months have been recorded in animal models, and histological and synaptic tracing analysis suggest a reduction of neuronal connectivity as a mechanism of action. The possibility of transferring this approach to epileptic patients is discussed in this review.

Perioperative FOLFOX 4 Versus FOLFOX 4 Plus Cetuximab Versus Immediate Surgery for High-Risk Stage II and III Colon Cancers: A Phase II Multicenter Randomized Controlled Trial (PRODIGE 22).

BACKGROUND: Perioperative chemotherapy has proven valuable in several tumors, but not in colon cancer (CC). OBJECTIVE: The aim of this study was to evaluate the efficacy and safety of perioperative chemotherapy in patients with locally advanced nonmetastatic CC. METHODS: This is a French multicenter randomized phase II trial in patients with resectable high-risk T3, T4, and/or N2 CC on baseline computed tomography (CT) scan. Patients were randomized to receive either 6 months of adjuvant FOLFOX after colectomy (control) or perioperative FOLFOX for 4 cycles before surgery and 8 cycles after (FOLFOX peri-op). In RAS wild-type patients, a third arm testing perioperative FOLFOX-cetuximab was added. Tumor Regression Grade (TRG1) of Ryan et al was the primary endpoint. Secondary endpoints were toxicity, perioperative morbidity, and quality of surgery. RESULTS: A total of 120 patients were enrolled. At interim analysis, the FOLFOX-cetuximab arm was stopped (lack of efficacy). The remaining 104 patients (control, n = 52; FOLFOX preop n = 52) represented our intention-to-treat population. In the FOLFOX perioperative group, 96% received the scheduled 4 cycles before surgery. R0 resection and complete mesocolic excision rate were 94% and 93%, respectively. Overall mortality and morbidity rates were similar in both groups. Perioperative FOLFOX chemotherapy did not improve major pathological response rate (TRG1 = 8%) but was associated with a significant pathological regression (TRG1-2 = 44% vs 8%, P < 0.001) and a trend to tumor downstaging as compared to the control group. CT scan criteria were associated with a 33% rate of overstaging in control group. CONCLUSIONS: Perioperative FOLFOX for locally advanced resectable CC is feasible with an acceptable tolerability but is not associated with an increased major pathological response rate as expected. However, perioperative FOLFOX induces pathological regression and downstaging. Better preoperative staging tools are needed to decrease the risk of overtreating patients.

Anomalous water dynamics in brain: a combined diffusion magnetic resonance imaging and neutron scattering investigation.

Water diffusion is an optimal tool for investigating the architecture of brain tissue on which modern medical diagnostic imaging techniques rely. However, intrinsic tissue heterogeneity causes systematic deviations from pure free-water diffusion behaviour. To date, numerous theoretical and empirical approaches have been proposed to explain the non-Gaussian profile of this process. The aim of this work is to shed light on the physics piloting water diffusion in brain tissue at the micrometre-to-atomic scale. Combined diffusion magnetic resonance imaging and first pioneering neutron scattering experiments on bovine brain tissue have been performed in order to probe diffusion distances up to macromolecular separation. The coexistence of free-like and confined water populations in brain tissue extracted from a bovine right hemisphere has been revealed at the micrometre and atomic scale. The results are relevant for improving the modelling of the physics driving intra- and extracellular water diffusion in brain, with evident benefit for the diffusion magnetic resonance imaging technique, nowadays widely used to diagnose, at the micrometre scale, brain diseases such as ischemia and tumours.

Prognostic factors in patients treated with second-line chemotherapy for advanced gastric cancer: results from the randomized prospective phase III FFCD-0307 trial.

AIM: The aim of this study was to determine prognostic factors in patients treated with second-line therapy (L2) for locally advanced or metastatic gastric and gastro-esophageal junction (GEJ) adenocarcinoma in a randomized phase III study with predefined L2. METHODS: In the FFCD-0307 study, patients were randomly assigned to receive in L1 either epirubicin, cisplatin, and capecitabine (ECX arm) or fluorouracil, leucovorin, and irinotecan (FOLFIRI arm). L2 treatment was predefined (FOLFIRI for the ECX arm and ECX for the FOLFIRI arm). Chi square tests were used to compare the characteristics of patients treated in L2 with those of patients who did not receive L2. Prognostic factors in L2 for progression-free survival (PFS) and overall survival (OS) were analyzed using a Cox model. RESULTS: Among 416 patients included, 101/209 (48.3%) patients in the ECX arm received FOLFIRI in L2, and 81/207 (39.1%) patients in the FOLFIRI arm received ECX in L2. Patients treated in L2, compared with those who only received L1 had : a better ECOG score (0-1: 90.4% versus 79.7%; p = 0.0002), more frequent GEJ localization (40.8% versus 27.6%; p = 0.005), and lower platelet count (median: 298000 versus 335000/mm3; p = 0.02). In multivariate analyses, age < 60 years at diagnosis (HR 1.49, 95% CI 1.09-2.03, p = 0.013) and ECOG score 2 before L2 (HR 2.62, 95% CI 1.41-4.84, p = 0.005) were the only significant poor prognostic factors for OS. CONCLUSION: Age ≥ 60 years at diagnosis and ECOG score 0/1 before L2 were the only favorable prognostic factors for OS.

FOLFIRINOX as induction treatment in rectal cancer patients with synchronous metastases: Results of the FFCD 1102 phase II trial.

AIM OF THE STUDY: The optimal therapeutic strategy in patients with rectal cancer and synchronous unresectable metastases remains unknown. We evaluated the efficacy of FOLFIRINOX induction therapy in this setting. PATIENTS AND METHODS: Chemotherapy-naïve patients received at least 8 cycles of FOLFIRINOX. The primary end-point was the 4-month disease control (4 m DC) rate. Tumour responses were centrally reviewed and assessed by computed tomography scan for metastases (Response Evaluation Criteria in Solid Tumours criteria) and magnetic resonance imaging for rectal tumorus. With a Simon 2-stage design and a targeted (H1) 4 m DC > 75%, 65 patients were enrolled from July 2012 to February 2015: male, 78%; median age, 61 years; performance status, 0-1, 98%; liver metastases, 92%; ≥2 metastatic sites, 63%. RESULTS: Fifty-six (85%) of the 65 patients received the 8 planned FOLFIRINOX cycles. The primary objective was achieved (4 m DC rate: 94%; 95% confidence interval [CI], 86.3-97.8). Primary tumour symptoms decreased from 72% at baseline to 10% at 4 months. Response rate was 86%, and a >70% primary tumour volume decrease was seen in 63% of patients. Forty-four patients (68%) had at least one grade 3 side-effect; no toxic deaths occurred. Median follow-up was 35.0 months (95% CI, 31.3-43.7). Median progression-free survival and overall survival were 10.9 m (95% CI, 8.8-12.9) and 33.4 m (95% CI, 22.6-38.2), respectively. CONCLUSION: Upfront FOLFIRINOX is feasible and allows good local and distant control. It therefore offers the opportunity to choose the best therapeutic strategy for each patient and to personalise treatment according to the local and distant efficacy results of this induction step. TRIAL REGISTRATION: Clinicaltrials.gov, NCT01674309.

Mapping of brain tissue hematocrit in glioma and acute stroke using a dual autoradiography approach.

Hematocrit (Hct) determines the ability of blood to carry oxygen. While changes in systemic Hct are known to impact stroke or tumor control, changes in local (tissue) Hct (tHct) induced by these diseases have however received little attention. In this study, we evaluate tHct in acute stroke and in glioma models using a new approach to map tHct across the brain, a dual isotope autoradiography, based on injections of 125I-labeled albumin and 99mTc-lalbeled red blood cells in the same animal. For validation purpose, tHct was mapped in the rat brain (i) under physiological conditions, (ii) following erythropoietin injection, and (iii) following hemodilution. Then, tHct was then mapped in stroke (middle cerebral artery occlusion) and tumor models (9LGS and C6). The mean tHct values observed in healthy brains (tHct = 29 ± 1.3%), were modified as expected by erythropoietin (tHct = 36.7 ± 2.6%) and hemodilution (tHct = 24.2 ± 2.4%). Using the proposed method, we observed a local reduction, spatially heterogeneous, in tHct following acute stroke (tHct = 19.5 ± 2.5%) and in both glioma models (9LGS: tHct = 18.5 ± 2.3%, C6: tHct = 16.1 ± 1.2%). This reduction and this heterogeneity in tHct observed in stroke and glioma raises methodological issues in perfusion imaging techniques where tHct is generally overlooked and could impact therapeutic strategies.

Geriatric analysis from PRODIGE 20 randomized phase II trial evaluating bevacizumab + chemotherapy versus chemotherapy alone in older patients with untreated metastatic colorectal cancer.

BACKGROUND: Older patients have frailty characteristics that impair the transposition of treatment results found in younger patients. Predictive factors are needed to help with treatment choices for older patients. The PRODIGE 20 study is a randomized phase II study that evaluated chemotherapy associated with bevacizumab (BEV) or not (CT) in patients aged 75 years or older. PATIENTS AND METHODS: Patients underwent a geriatric assessment at randomization and at each evaluation. The predictive value of geriatric and oncologic factors was determined for the primary composite end-point assessing safety and efficacy of treatment (BEV or CT) simultaneously and also progression-free survival (PFS) and overall survival (OS). RESULTS: 102 patients were randomized (51 BEV and 51 CT; median age 80 years [range 75-91]). On multivariate analysis, baseline normal independent activity of daily living (IADL) score and no previous cardiovascular disease predicted the primary end-point. High (versus low) baseline Köhne score predicted short PFS and baseline Spitzer quality of life (QoL) score <8, albumin level ≤35 g/L, CA19.9 >2 LN levels above normal and high baseline Köhne score predicted short OS. Survival without deteriorated QoL and autonomy was similar with BEV and CT. On subgroup analyses, the benefit of bevacizumab seemed to be maintained in patients with baseline impaired IADL or nutritional status. CONCLUSION: Normal IADL score was associated with a good efficacy and safety of both BEV and CT. Köhne criteria may be relevant prognostic factors in older patients. Adding bevacizumab to chemotherapy does not impair patient autonomy or QoL.

Fungal Planet description sheets: 785-867.

Novel species of fungi described in this study include those from various countries as follows: Angola, Gnomoniopsis angolensis and Pseudopithomyces angolensis on unknown host plants. Australia, Dothiora corymbiae on Corymbia citriodora, Neoeucasphaeria eucalypti (incl. Neoeucasphaeria gen. nov.) on Eucalyptus sp., Fumagopsis stellae on Eucalyptus sp., Fusculina eucalyptorum (incl. Fusculinaceae fam. nov.) on Eucalyptus socialis, Harknessia corymbiicola on Corymbia maculata, Neocelosporium eucalypti (incl. Neocelosporium gen. nov., Neocelosporiaceae fam. nov. and Neocelosporiales ord. nov.) on Eucalyptus cyanophylla, Neophaeomoniella corymbiae on Corymbia citriodora, Neophaeomoniella eucalyptigena on Eucalyptus pilularis, Pseudoplagiostoma corymbiicola on Corymbia citriodora, Teratosphaeria gracilis on Eucalyptus gracilis, Zasmidium corymbiae on Corymbia citriodora. Brazil, Calonectria hemileiae on pustules of Hemileia vastatrix formed on leaves of Coffea arabica, Calvatia caatinguensis on soil, Cercospora solani-betacei on Solanum betaceum, Clathrus natalensis on soil, Diaporthe poincianellae on Poincianella pyramidalis, Geastrum piquiriunense on soil, Geosmithia carolliae on wing of Carollia perspicillata, Henningsia resupinata on wood, Penicillium guaibinense from soil, Periconia caespitosa from leaf litter, Pseudocercospora styracina on Styrax sp., Simplicillium filiforme as endophyte from Citrullus lanatus, Thozetella pindobacuensis on leaf litter, Xenosonderhenia coussapoae on Coussapoa floccosa. Canary Islands (Spain), Orbilia amarilla on Euphorbia canariensis. Cape Verde Islands, Xylodon jacobaeus on Eucalyptus camaldulensis. Chile, Colletotrichum arboricola on Fuchsia magellanica. Costa Rica, Lasiosphaeria miniovina on tree branch. Ecuador, Ganoderma chocoense on tree trunk. France, Neofitzroyomyces nerii (incl. Neofitzroyomyces gen. nov.) on Nerium oleander. Ghana, Castanediella tereticornis on Eucalyptus tereticornis, Falcocladium africanum on Eucalyptus brassiana, Rachicladosporium corymbiae on Corymbia citriodora. Hungary, Entoloma silvae-frondosae in Carpinus betulus-Pinus sylvestris mixed forest. Iran, Pseudopyricularia persiana on Cyperus sp. Italy, Inocybe roseascens on soil in mixed forest. Laos, Ophiocordyceps houaynhangensis on Coleoptera larva. Malaysia, Monilochaetes melastomae on Melastoma sp. Mexico, Absidia terrestris from soil. Netherlands, Acaulium pannemaniae, Conioscypha boutwelliae, Fusicolla septimanifiniscientiae, Gibellulopsis simonii, Lasionectria hilhorstii, Lectera nordwiniana, Leptodiscella rintelii, Parasarocladium debruynii and Sarocladium dejongiae (incl. Sarocladiaceae fam. nov.) from soil. New Zealand, Gnomoniopsis rosae on Rosa sp. and Neodevriesia metrosideri on Metrosideros sp. Puerto Rico, Neodevriesia coccolobae on Coccoloba uvifera, Neodevriesia tabebuiae and Alfaria tabebuiae on Tabebuia chrysantha. Russia, Amanita paludosa on bogged soil in mixed deciduous forest, Entoloma tiliae in forest of Tilia × europaea, Kwoniella endophytica on Pyrus communis. South Africa, Coniella diospyri on Diospyros mespiliformis, Neomelanconiella combreti (incl. Neomelanconiellaceae fam. nov. and Neomelanconiella gen. nov.) on Combretum sp., Polyphialoseptoria natalensis on unidentified plant host, Pseudorobillarda bolusanthi on Bolusanthus speciosus, Thelonectria pelargonii on Pelargonium sp. Spain, Vermiculariopsiella lauracearum and Anungitopsis lauri on Laurus novocanariensis, Geosmithia xerotolerans from a darkened wall of a house, Pseudopenidiella gallaica on leaf litter. Thailand, Corynespora thailandica on wood, Lareunionomyces loeiensis on leaf litter, Neocochlearomyces chromolaenae (incl. Neocochlearomyces gen. nov.) on Chromolaena odorata, Neomyrmecridium septatum (incl. Neomyrmecridium gen. nov.), Pararamichloridium caricicola on Carex sp., Xenodactylaria thailandica (incl. Xenodactylariaceae fam. nov. and Xenodactylaria gen. nov.), Neomyrmecridium asiaticum and Cymostachys thailandica from unidentified vine. USA, Carolinigaster bonitoi (incl. Carolinigaster gen. nov.) from soil, Penicillium fortuitum from house dust, Phaeotheca shathenatiana (incl. Phaeothecaceae fam. nov.) from twig and cone litter, Pythium wohlseniorum from stream water, Superstratomyces tardicrescens from human eye, Talaromyces iowaense from office air. Vietnam, Fistulinella olivaceoalba on soil. Morphological and culture characteristics along with DNA barcodes are provided.

MR Vascular Fingerprinting in Stroke and Brain Tumors Models.

In this study, we evaluated an MRI fingerprinting approach (MRvF) designed to provide high-resolution parametric maps of the microvascular architecture (i.e., blood volume fraction, vessel diameter) and function (blood oxygenation) simultaneously. The method was tested in rats (n = 115), divided in 3 models: brain tumors (9 L, C6, F98), permanent stroke, and a control group of healthy animals. We showed that fingerprinting can robustly distinguish between healthy and pathological brain tissues with different behaviors in tumor and stroke models. In particular, fingerprinting revealed that C6 and F98 glioma models have similar signatures while 9 L present a distinct evolution. We also showed that it is possible to improve the results of MRvF and obtain supplemental information by changing the numerical representation of the vascular network. Finally, good agreement was found between MRvF and conventional MR approaches in healthy tissues and in the C6, F98, and permanent stroke models. For the 9 L glioma model, fingerprinting showed blood oxygenation measurements that contradict results obtained with a quantitative BOLD approach. In conclusion, MR vascular fingerprinting seems to be an efficient technique to study microvascular properties in vivo. Multiple technical improvements are feasible and might improve diagnosis and management of brain diseases.

Cell-based therapy for traumatic brain injury.

Traumatic brain injury is a major economic burden to hospitals in terms of emergency department visits, hospitalizations, and utilization of intensive care units. Current guidelines for the management of severe traumatic brain injuries are primarily supportive, with an emphasis on surveillance (i.e. intracranial pressure) and preventive measures to reduce morbidity and mortality. There are no direct effective therapies available. Over the last fifteen years, pre-clinical studies in regenerative medicine utilizing cell-based therapy have generated enthusiasm as a possible treatment option for traumatic brain injury. In these studies, stem cells and progenitor cells were shown to migrate into the injured brain and proliferate, exerting protective effects through possible cell replacement, gene and protein transfer, and release of anti-inflammatory and growth factors. In this work, we reviewed the pathophysiological mechanisms of traumatic brain injury, the biological rationale for using stem cells and progenitor cells, and the results of clinical trials using cell-based therapy for traumatic brain injury. Although the benefits of cell-based therapy have been clearly demonstrated in pre-clinical studies, some questions remain regarding the biological mechanisms of repair and safety, dose, route and timing of cell delivery, which ultimately will determine its optimal clinical use.

[Initial experience of first 225 flexible ureteroscopy with laser lithotripsy in a primary care hospital]. / Expérience initiale de 225 premiers cas d'urétéroscopie souple laser dans un centre hospitalier périphérique.

INTRODUCTION: During the last decade, the advent of flexible ureteroscopy with laser lithotripsy has revolutionized the management of upper urinary tract stones. Our center is a primary care hospital that is equipped with this technology since January 2011. This study reported our initial experience of first 225 cases. MATERIEL AND METHODS: This study is a descriptive, retrospective and monocentric analysis. The first 225 cases, operated consecutively by 3 surgeons during 26 months, were analyzed. We have used 2 flexible ureteroscopes (1 digital, 1 optical). Laser source was an Holmium laser (Stonelight) at a power of 5 watts. RESULTS: The mean age was 53 years (± 10.2) and the mean stones size was 11 mm (2.3). In 49% of cases, ureteroscopy was chosen for the first, without prior treatment. In 59% of cases, ureteroscopy was used after failure of other treatment (ESWL in 70% of cases). The mean operative time was 72 minutes (± 16.6) and the mean length of stay was 2.6 days (± 0.8). The first session of ureteroscopy was a success in 93% of cases without residual fragments after 1 month. The frequency of postoperative complications was estimated at 8% (Clavien I and II). CONCLUSION: Flexible ureteroscopy with laser lithotripsy was a safe and effective technique, allowing the treatment of all upper urinary tract stones, especially on failure of other treatment. Its place in the first intention is widespread in our exercise, especially among obese patients, patients on anticoagulant therapy or with stone of the lower pole.

[Eight years of experience in robot-assisted partial nephrectomy: oncological and functional outcomes]. / Huit ans d'expérience en néphrectomie partielle robot-assistée: résultats carcinologiques et fonctionnels.

INTRODUCTION: Partial nephrectomy (PN) is currently the reference treatment for renal tumors of less than 4 cm in size (T1a). Laparoscopic PN is difficult to perform, with the main consequence being an increase in warm ischemia time and morbidity. In facilitating the surgical procedure, robotics combines the benefits of minimally invasive and conservative surgery. We report here 8 years of experience with 110 robot-assisted partial nephrectomies (RAPN). The objective of this study was to analyze the oncological and functional outcomes. PATIENTS AND METHODS: Between March 2005 and September 2012, 110 patients underwent RAPN. The epidemiological and surgical data and the oncological and functional outcomes were retrospectively collected and analyzed. RESULTS: Seventy-six men and 34 women underwent surgery. The mean age was 59.6 ± 14.2 years. Mean operative time was 141.3 ± 36.1 minutes with a warm ischemia time of 21.2 ± 8.8 minutes. Mean hospital stay was 5.3 ± 2.2 days. Mean tumor size was 27.4 ± 9.8mm with 82.7% malignant tumors, of which 62.7% were clear cell carcinomas. Surgical margins were healthy in 100% of cases. After a mean follow-up of 28.7 ± 18.5 months, no recurrence was noted. On a functional level, there was no short-term or medium-term impairment of renal function. The frequency of postoperative complications was estimated as 12% including 7% of surgical complications (3 arterial pseudoaneurysms, 4 episodes of bleeding from the cut surface and 1 conversion to laparotomy). CONCLUSION: Robotics brought surgeon dexterity, meticulousness and precision. These qualities are essential in conservative renal surgery and made RAPN a safe and effective technique that gives good short and medium-term oncological and functional results.

The histidine triad nucleotide binding 1 protein is involved in nicotine reward and physical nicotine withdrawal in mice.

Smoking rates among individuals with schizophrenia are significantly higher than the general population. One possible explanation for this comorbidity is that there are shared genes and biological pathways between smoking and schizophrenia. The histidine triad nucleotide binding protein 1 (HINT1) is a potential candidate, as genetic association and expression studies implicate the gene in both schizophrenia and nicotine dependence; however, the behavioral role of HINT1 in nicotine dependence is unknown. Thus, the goal of the current study was to determine the behavioral role of HINT1 in nicotine dependence. We tested male HINT1 wild-type (+/+) and knockout (-/-) mice in the nicotine conditioned place preference (CPP) test of reward, a nicotine withdrawal model assessing both physical and affective signs, and the nicotine withdrawal conditioned place aversion (CPA) test. HINT1 -/- mice failed to develop a significant nicotine CPP and physical withdrawal signs (hyperalgesia and somatic signs) were attenuated in HINT1 -/- mice. Conversely, HINT1 -/- mice developed a significant nicotine withdrawal CPA similar to their ++ counterparts. Overall, our data support a role for the HINT1 gene in mediating behaviors associated with nicotine reward and physical nicotine withdrawal, and provide insight into the role of HINT1 in nicotine dependence-like behaviors.

Acute behavioral effects of nicotine in male and female HINT1 knockout mice.

Human genetic association and brain expression studies, and mouse behavioral and molecular studies implicate a role for the histidine triad nucleotide-binding protein 1 (HINT1) in schizophrenia, bipolar disorder, depression and anxiety. The high comorbidity between smoking and psychiatric disorders, schizophrenia in particular, is well established. Associations with schizophrenia and HINT1 are also sex specific, with effects more predominant in males; however, it is unknown if sex differences associated with the gene extend to other phenotypes. Thus, in this study, using a battery of behavioral tests, we elucidated the role of HINT1 in acute nicotine-mediated behaviors using male and female HINT1 wild-type (+/+) and knockout (-/-) mice. The results show that male HINT1 -/- mice were less sensitive to acute nicotine-induced antinociception in the tail-flick, but not hot-plate test. At low nicotine doses, male and female HINT1 -/- mice were less sensitive to nicotine-induced hypomotility, although the effect was more pronounced in females. Baseline differences in locomotor activity observed in male HINT1 +/+ and -/- mice were absent in females. Nicotine did not produce an anxiolytic effect in male HINT1 -/- mice, but rather an anxiogenic response. Diazepam also failed to induce an anxiolytic response in these mice, suggesting a general anxiety phenotype not specific to nicotine. Differences in anxiety-like behavior were not observed in female mice. These results further support a role for HINT1 in nicotine-mediated behaviors and suggest that alterations in the gene may have differential effects on phenotype in males and females.

Monochromatic minibeam radiotherapy: theoretical and experimental dosimetry for preclinical treatment plans.

Monochromatic x-ray minibeam radiotherapy is a new radiosurgery approach based on arrays of submillimetric interlaced planar x-ray beams. The aim of this study was to characterize the dose distributions obtained with this new modality when being used for preclinical trials. Monte Carlo simulations were performed in water phantoms. Percentage depth-dose curves and dose profiles were computed for single incidences and interleaved incidences of 80 keV planar x-ray minibeam (0.6 × 5 mm) arrays. Peak to valley dose ratios were also computed at various depths for an increasing number of minibeams. 3D experimental polymer gel (nPAG) dosimetry measurements were performed using MRI devices designed for small animal imaging. These very high spatial resolution (50 µm) dose maps were compared to the simulations. Preclinical minibeams dose distributions were fully characterized. Experimental dosimetry correlated well with Monte Carlo calculations (Student t-tests: p > 0.1). F98 tumor-bearing rats were also irradiated with interleaved minibeams (80 keV, prescribed dose: 25 Gy). This associated preclinical trial serves as a proof of principle of the technique. The mean survival time of irradiated glioma-bearing rats increased significantly, when compared to the untreated animals (59.6 ± 2.8 days versus 28.25 ± 0.75 days, p < 0.001).

Involvement of A2A receptors in anxiolytic, locomotor and motivational properties of ethanol in mice.

We have shown previously that mice lacking the adenosine A2A receptor (A2AR) generated on a CD1 background self-administer more ethanol and exhibit hyposensitivity to acute ethanol. We aimed to investigate if the increased propensity of A2A(-/-) mice to consume ethanol is associated with an altered sensitivity in the motivational properties of ethanol in the conditioned place preference (CPP) and conditioned taste aversion (CTA) paradigms and with an altered development of sensitization to the locomotor effects of ethanol. We also tested their sensitivity to the anxiolytic effects of ethanol. Our results show that A2A(-/-) mice produced on a CD1 background displayed a reduced ethanol-induced CPP and an increased sensitivity to the anxiolytic and locomotorstimulant effects of ethanol, but they did not show alteration in ethanol-induced CTA and locomotor sensitization. Ethanol-induced CPP, ethanol consumption and the locomotor effects of ethanol were also tested in A2A(-/-) mice produced on a C57BL/6J background. Our results emphasized the importance of the genetic background because alteration in ethanol consumption and preference, ethanol-induced CPP and locomotor-stimulant effects were not found in knockout mice produced on the alcohol-preferring C57BL/6J genetic background. Finally, the A2AR agonist, 2-p-(2-carboxyethyl)-phenylethylamino-50-N-ethylcarboxamidoadenosine hydrochloride (CGS 21680), reduced ethanol consumption and preference in C57BL/6J mice. In conclusion, A2AR deficiency in mice generated on a CD1 background leads to high ethanol consumption that is associated with an increased sensitivity to the locomotor-stimulant/anxiolytic effects of ethanol and a decrease in ethanol-induced CPP.

A model of the dual effect of gadopentetate dimeglumine on dynamic brain MR images.

An optimized dynamic gradient echo sequence with two echoes is used to obtain data that can be analyzed with indicator dilution theory as well as with pharmacokinetic theory. Taking advantage of the simultaneity of T(*)(2) and T(1) information, both theories can be employed and merged to interpret consistently the observed effects of the redistribution of a contrast agent (gadopentetate dimeglumine) into the tissue from first pass onward. The regional cerebral blood volume (rCBV) and the exchange rate of the contrast agent between the vascular and the interstitial space through the blood-brain barrier are analyzed for each pixel in a two-step algorithm. Two values for rCBV are obtained with different weighting for the microvascular fraction of the blood volume. Because the analysis, called PELEAKAN, is capable of separating effects related to perfusion (through intravascular blood volume) and to leakage in places where the blood-brain barrier is damaged, it is an appropriate tool for evaluating these parameters in brain tumors, and we show clinical examples of this analysis in brain tumor patients.

Stimulation of Ca2+ influx in rat pituitary cells under exposure to a 50 Hz magnetic field.

The effect of exposure of single rat pituitary cells to 50 Hz sine wave magnetic fields of various strengths on the intracellular free Ca2+ concentration ([Ca2+]i), was studied by using dual-emission microfluorimetry, using indo-1 as probe. A 30 min exposure of the cells to vertical 50 microT peak magnetic field triggered a long-lasting increase in [Ca2+]i from a basal value of about 185 +/- 4 nM to 326 +/- 41 nM (S.E.; n = 150). The vertical and horizontal components of the static magnetic field were 57 and 15 microT, respectively. The 50 Hz ambient magnetic field was always below 0.1 microT rms. The effect was observed both at 25 +/- 2 degrees C and at 37 +/- 2 degrees C. Responsive cells, for which [Ca2+]i rose to values above 309 nM, were identified as lactotrophs and represented 29% of the total pituitaries. [Ca2+]i increase, for the most part, was due to Ca2+ influx through voltage-dependent dihydropiridine-sensitive calcium channels inhibited by PN 200-110. However, neither Ca2+ channel blockers nor removal of Ca2+ from the external medium during exposure completely prevented the field-induced [Ca2+]i increase. Additional experiments using an MTT colorimetric assay showed that alteration of Ca2+ homeostasis of lactotrophs was associated with impairment of some mitochondrial processes.

The joining of germ-line V alpha to J alpha genes replaces the preexisting V alpha-J alpha complexes in a T cell receptor alpha, beta positive T cell line.

To determine whether T cell receptor genes follow the same principle of allelic exclusion as B lymphocytes, we have analyzed the rearrangements and expression of TCR alpha and beta genes in the progeny of the CD3+, CD4-/CD8- M14T line. Here, we show that this line can undergo secondary rearrangements that replace the pre-existing V alpha-J alpha rearrangements by joining an upstream V alpha gene to a downstream J alpha segment. Both the productively and nonproductively rearranged alleles in the M14T line can undergo secondary rearrangements while its TCR beta genes are stable. These secondary recombinations are usually productive, and new forms of TCR alpha polypeptides are expressed in these cells in association with the original C beta chain. Developmental control of this V alpha-J alpha replacement phenomenon could play a pivotal role in the thymic selection of the T cell repertoire.

Rearrangement and expression of T cell receptor and immunoglobulin loci in immortalized CD4-CD8- T cell lines.

Injection of newborn mice with mixtures of wild-type moloney murine leukemia (Mo-MuLV) virus and other recombinant retroviruses harboring the myc oncogene alone or in combination with the H-ras oncogene resulted in a 100% incidence of lymphatic leukemias from which permanent cell lines could be established in vitro. These cells are immunoglobulin (Ig)-, Thy-1+BP- and CD8-CD4- indicating that they are early thymocytes. Such transformed pre-T lines lack retroviral myc and ras genes but occasionally possess proviral insertion near to their endogenous myc and pim genes. We show that both Ig heavy chain (Igh) and T cell receptor (TcR) genes are rearranged in most of these lines. In some cases, a primary recombination was followed by a secondary rearrangement at the same locus. We show that VT gamma genes can rearrange outside of their known cluster suggesting that TcR gamma diversification in such pre-T cells may be different to that in more mature T cells. Ig D-JH recombinations may precede TcR gene recombination in these early T cell lines, and some but not all express sterile Cmu transcripts. Some of these lines express surface heterodimers that appear composed of alpha and beta chains that can be immunoprecipitated with a monoclonal anti-T3 antibody but not with the anti-V beta 8 monoclonal antibody F23.1. This established pre-T cell line represents novel biological material for the dissection of T cell development and function analogous to A-MuLV transformed pre-B cells.