Existence of nitric oxide synthase in rat hippocampal pyramidal cells.

It has been proposed that nitric oxide (NO) serves as a key retrograde messenger during long-term potentiation at hippocampal synapses, linking induction of long-term potentiation in postsynaptic CA1 pyramidal cells to expression of long-term potentiation in presynaptic nerve terminals. However, nitric oxide synthase (NOS), the proposed NO-generating enzyme, has not yet been detected in the appropriate postsynaptic cells. We here demonstrate specific NOS immunoreactivity in the CA1 region of hippocampal sections by using an antibody specific for NOS type I and relatively gentle methods of fixation. NOS immunoreactivity was found in dendrites and cell bodies of CA1 pyramidal neurons. Cultured hippocampal pyramidal cells also displayed specific immunostaining. Control experiments showed no staining with preimmune serum or immune serum that was blocked with purified NOS. These results demonstrate that CA1 pyramidal cells contain NOS, as required were NO involved in retrograde signaling during hippocampal synaptic plasticity.     

Common and rare alleles of the serotonin transporter gene,SLC6A4, associated with Tourette's disorder

To evaluate the hypothesis that functionally over‐expressing alleles of the serotonin transporter (SERT) gene (solute carrier family 6, member 4, SLC6A4) are present in Tourette's disorder (TD), just as we previously observed in obsessive compulsive disorder (OCD), we evaluated TD probands (N = 151) and controls (N = 858). We genotyped the refined SERT‐linked polymorphic region 5‐HTTLPR/rs25531 and the associated rs25532 variant in the SLC6A4 promoter plus the rare coding variant SERT isoleucine‐to‐valine at position 425 (I425V). The higher expressing 5‐HTTLPR/rs25531 L_A allele was more prevalent in TD probands than in controls (χ² = 5.75; P = 0.017; odds ratio [OR], 1.35); and, in a secondary analysis, surprisingly, it was significantly more frequent in probands who had TD alone than in those who had TD plus OCD (Fisher's exact test; P = 0.0006; OR, 2.29). Likewise, the higher expressing L_AC haplotype (5‐HTTLPR/rs25531/rs25532) was more frequent in TD probands than in controls (P = 0.024; OR, 1.33) and also in the TD alone group versus the TD plus OCD group (P = 0.0013; OR, 2.14). Furthermore, the rare gain‐of‐function SERT I425V variant was observed in 3 male siblings with TD and/or OCD and in their father. Thus, the cumulative count of SERT I425V becomes 1.57% in OCD/TD spectrum conditions versus 0.15% in controls, with a recalculated, family‐adjusted significance of χ² = 15.03 (P < 0.0001; OR, 9.0; total worldwide genotyped, 2914). This report provides a unique combination of common and rare variants in one gene in TD, all of which are associated with SERT gain of function. Thus, altered SERT activity represents a potential contributor to serotonergic abnormalities in TD. The present results call for replication in a similarly intensively evaluated sample. © 2013 Movement Disorder Society     

Use of <Emphasis Type="Italic">MET3</Emphasis> promoters for regulated gene expression in <Emphasis Type="Italic">Ashbya gossypii</Emphasis>

A central tool for gene function analysis is the construction mutant strains. This can be done conveniently in A. gossypii using PCR-based tools. The deletion of essential genes can be performed since initial transformants are sheltered in a heterokaryotic mycelium, which contains nuclei with both wild type and mutant alleles. The analysis of mutant phenotypes in A. gossypii is regularly started by germinating spores, which contain only one nucleus. Thus, selection can be used to identify mutant germ cells and germlings. However, such an analysis yields only mutant mycelia if the deleted gene is not essential. We describe the use of the regulatable Saccharomyces cerevisiae and A. gossypii MET3 promoters as novel tools to regulate gene expression in A. gossypii. Conditional expression was tested using GFP and lacZ-reporter genes. Regulation of MET3 promoters was found to be dependent on methionine but not on cysteine and down-regulation to about 1/10 of the initial expression levels was achieved. We used the A. gossypii WAL1 and CYK1 genes as models to demonstrate that MET3 promoters could regulate the expression of these genes and reveal their mutant phenotypes depending on the presence or absence of methionine. Finally, we show that the AgMET3 promoter contains two Cpf1-binding sites and that AgCPF1 can complement the S. cerevisiae cpf1 methionine auxotrophy.     

Assessment of myocardial salvage after ischemia and reperfusion using magnetic resonance imaging and spectroscopy

To test the hypothesis that contrast-enhanced magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) can differentiate reversible from irreversible myocardial injury, these modalities were used to study ischemia and reperfusion in a rat model. The presence of ischemia and reperfusion were confirmed with radiolabeled microspheres (n = 6). Groups of animals were subjected to either 16 (n = 17), 30 (n = 14), 60 (n = 11), or 90 (n = 14) minutes of left coronary artery (LCA) occlusion and 60 minutes reperfusion. After albumin-gadolinium (Gd)-DTPA injection, contrast-enhanced, T1-weighted, spin-echo proton images were acquired at baseline and every 16 minutes during LCA occlusion and reperfusion. In separate experiments, 31phosphorus (31P) spectra were acquired at similar time points during ischemia and reperfusion. After 16 minutes occlusion, normally perfused myocardium enhanced significantly compared with ischemic myocardium on MRI (104 +/- 7.9% vs. 61 +/- 11.0%, p less than 0.05, n = 5, mean +/- SEM, % of baseline value). MRS showed reduced phosphocreatine (PCr) and adenosine triphosphate (ATP) (58.8 +/- 2.4%, p less than or equal to 0.01; 81.4 +/- 2.4, p less than or equal to 0.01, n = 12). After 16 or 30 minutes ischemia, reflow resulted in uniform MRI signal intensity of the ischemic zone compared with normal myocardium (93.5 +/- 11.3 vs. 80.9 +/- 7.0, p = NS, n = 11, % of baseline value at 30 minutes reperfusion) and PCr recovery on MRS (94.3 +/- 4.0%, p = NS, n = 20, % baseline value at 30 minutes reflow). After 60 and 90 minutes ischemia, reflow resulted in marked enhancement of reperfused compared with normal myocardium on MRI (254.0 +/- 30.0 vs. 78.3 +/- 9.2, p less than or equal to 0.01, n = 10) and no recovery of PCr on MRS (64.1 +/- 3.0, p = NS, n = 14). Triphenyltetrazolium chloride (TTC) staining revealed transmural myocardial infarction (MI) in all hearts subjected to 60 or 90 minutes ischemia and reflow, and small nontransmural MIs in only 2/11 hearts subjected to 16 or 30 minutes ischemia and reperfusion. Thus, 1) MRI with albumin-Gd-DTPA is useful for identifying myocardial ischemia by enhancing the contrast between normally perfused and ischemic myocardia; 2) MRI with albumin-Gd-DTPA is useful for identifying reperfusion after myocardial ischemia; and 3) after reperfusion, reversible can be distinguished from irreversible myocardial injury by characteristic findings on MRI and MRS.     

The joint impact of donor and recipient parameters on the outcome of heart transplantation in Germany after graft allocation

Organ shortage in heart transplantation (HTx) results in increased use of grafts from donors with substantial risk factors. It is discussed controversially which donor characteristics may be detrimental. Therefore, we evaluated the joint impact of donor‐ and patient‐related risk factors in HTx on patient survival by multiple analysis in a nationwide multicentre study after donor selection was carried out. The research database consists of data concerning hearts donated and transplanted in Germany between 2006 and 2008 as provided by Deutsche Stiftung Organtransplantation and the BQS Institute. Multiple Cox regression (significance level 5%, hazard ratio [95% CI]) was conducted (n = 774, recipient age ≥ 18 years). Survival was significantly decreased by donor age (1.021 [1.008–1.035] per year), nontraumatic cause of death (1.481 [1.079–2.034]), troponin >0.1 ng/ml (2.075 [1.473–2.921]), ischaemia time (1.197 [1.041–1.373] per hour), recipient age (1.017 [1.002–1.031] per year) and in recipients with pulmonary vascular resistance ≥320 dyn*s*cm^?5 (1.761 [1.115–2.781]), with ventilator dependency (3.174 [2.211–6.340]) or complex previous heart surgery (1.763 [1.270–2.449]). After donor selection had been conducted, multiple Cox regression revealed donor age, nontraumatic cause of death, troponin and ischaemia time as well as recipient age, pulmonary hypertension, ventilator dependency and previous complex heart surgery as limiting risk factors concerning patient survival.     

Three-dimensional MR imaging of pulmonary vessels and parenchyma with NC100150 injection (Clariscan)

The influence of increasing doses of NC100150 Injection (Clariscantrade mark) and echo times on visualization of pulmonary vessels and parenchyma was evaluated. The effects of 0.5, 1, 2, 4, and 8 mg Fe/kg NC100150 Injection and echo times (TE) of 1.1, 1.8, 2. 2, and 4.3 msec were determined in six dogs using breath-hold three-dimensional (3D) spoiled gradient-echo magnetic resonance (MR) sequence. At 2 mg Fe/kg and TE of 1.1 msec, the signal-to-noise ratio of the central pulmonary arteries and parenchyma was significantly increased (5.3 +/- 2.2 to 50.3 +/- 2.4) and (2.2 +/- 0. 9 to 6.4 +/- 1.1), respectively. Using the TE of 1.1 msec, signal intensity in the main arteries continued to increase with increasing dose. Moreover, the enhancement of pulmonary parenchyma and microvasculature had a positive dose response. 3D MR imaging with ultrashort echo time and 2 mg Fe/kg NC100150 Injection produces angiograms with strong vascular contrast and allows qualitative assessment of pulmonary parenchyma and microvasculature.     

Early detection of regional cerebral ischemia in cats: comparison of diffusion- and T2-weighted MRI and spectroscopy

Diffusion-weighted MR images were compared with T2-weighted MR images and correlated with 1H spin-echo and 31P MR spectroscopy for 6-8 h following a unilateral middle cerebral and bilateral carotid artery occlusion in eight cats. Diffusion-weighted images using strong gradient strengths (b values of 1413 s/mm2) displayed a significant relative hyperintensity in ischemic regions as early as 45 min after onset of ischemia whereas T2-weighted spin-echo images failed to clearly demonstrate brain injury up to 2-3 h postocclusion. Signal intensity ratios (SIR) of ischemic to normal tissues were greater in the diffusion-weighted images at all times than in either TE 80 or TE 160 ms T2-weighted MR images. Diffusion- and T2-weighted SIR did not correlate for the first 1-2 h postocclusion. Good correlation was found between diffusion-weighted SIR and ischemic disturbances of energy metabolism as detected by 31P and 1H MR spectroscopy. Diffusion-weighted hyperintensity in ischemic tissues may be temperature-related, due to rapid accumulation of diffusion-restricted water in the intracellular space (cytotoxic edema) resulting from the breakdown of the transmembrane pump and/or to microscopic brain pulsations.     

Lorsque maternité et cancer se rencontrent : influence réciproque de deux processus antagonistes

This article deals with the question of psychological impact of the discovery of a cancer disease in women experiencing the perinatal period. The authors first review the scientific literature on the convergence between cancer and motherhood. They present then their understanding on this topic by describing and discussing two qualitative case studies that illustrate the hypothesis of a mutual influence between these two antagonistic processes: psychic adjustment to the disease and the motherhood process.     

Quantitative tissue oxygen measurement in multiple organs using 19F MRI in a rat model

Measurement of individual organ tissue oxygen levels can provide information to help evaluate and optimize medical interventions in many areas including wound healing, resuscitation strategies, and cancer therapeutics. Echo planar ¹⁹F MRI has previously focused on tumor oxygen measurement at low oxygen levels (pO₂) <30 mmHg. It uses the linear relationship between spin‐lattice relaxation rate (R₁) of hexafluorobenzene (HFB) and pO₂. The feasibility of this technique for a wider range of pO₂values and individual organ tissue pO₂ measurement was investigated in a rat model. Spin‐lattice relaxation times (T₁= 1/R₁) of hexafluorobenzene were measured using ¹⁹F saturation recovery echo planar imaging. Initial in vitro studies validated the linear relationship between R₁ and pO₂ from 0 to 760 mmHg oxygen partial pressure at 25, 37, and 41°C at 7 Tesla for hexafluorobenzene. In vivo experiments measured rat tissue oxygen (ptO2) levels of brain, kidney, liver, gut, muscle, and skin during inhalation of both 30 and 100% oxygen. All organ ptO₂ values significantly increased with hyperoxia (P < 0.001). This study demonstrates that ¹⁹F MRI of hexafluorobenzene offers a feasible tool to measure regional ptO2 in vivo, and that hyperoxia significantly increases ptO2 of multiple organs in a rat model. Magn Reson Med, 2011. © 2011 Wiley Periodicals, Inc.