Effect of Chronic Manganese Treatment on Adenosine Tissue Levels and Adenosine A2a Receptor Binding in Diverse Regions of Mouse Brain

In the present study the effects of chronic manganese (Mn) treatment on adenosine A_2a receptor binding in mouse brain have been assessed. Male albino mice were divided in two groups: In the Mn-treated group, the animals were injected intraperitoneally (i.p.) with MnCl₂ (5 mg/kg/day) five days per week during 9 weeks; in the control group, they were injected likewise with a saline solution. A significant decrease of the Kd without alteration of Bmax in the cerebellum and, an increase of the Kd and Bmax in hippocampus of mice treated with Mn were found. Also, an increase of Kd in frontal cortex was observed. The binding parameters in caudate nucleus, olfactory bulb and hypothalamus were not altered by Mn. A significant decrease in the adenosine concentration in caudate nucleus, olfactory bulb and hypothalamus, without significant changes in hippocampus, frontal cortex and cerebellum was also detected. These findings suggest that chronic administration of Mn could affect adenosine receptor function and turnover, depending on the brain region analyzed.     

High Intensity Light Increases Olfactory Bulb Melatonin in Venezuelan Equine Encephalitis Virus Infection

In mice infected with the Venezuelan equine encephalomyelitis (VEE) virus and exposed to high intensity light (2500 lux) with a 12 h light: 12 h dark photoperiod, a significant increase in the levels of melatonin in the olfactory bulb was observed. The significance of these findings deserves further studies to understand the mechanisms involved in this effect since the olfactory bulbs have been proposed as first portal for VEE virus entry into the CNS. The increase in melatonin content could represent one of the mechanisms of defense against the viral attack.     

Masseter muscle activity during vestibular stimulation in man

Experimental data report that vestibular afferents affect trigeminal system activity. The aim of this work was to evaluate whether static vestibular stimulation affects the excitability of trigeminal motoneurons in man. In order to assess this, voluntary EMG activity of masseter muscles as well as duration and latency of the early and late components of EMG exteroceptive silent period were evaluated while keeping the subject in vertical position and during 20 degrees static tilt. The experiments were performed on ten adult subjects with no orofacial, neurologic and otologic disorders. Each subject sat on a chair, which kept the complex head-jaw-neck-trunk and the limbs securely fixed, in order to minimize any interference due to the activation of somatosensory and proprioceptive afferents from these districts. The subjects were instructed to contract masseter muscles at 25% of their maximum bite force and the isometric force monitoring was used as visual feedback. Exteroceptive silent period (ESP) of masseter EMG was elicited by electrically stimulating the inferior inter-incisal gum. Results showed that static vestibular stimulation induced asymmetrical responses on voluntary masseter muscle activity, which was reduced to 70.3 +/- 16.1% (mean +/- S.D.) of the control value during ipsilateral tilt and increased to 128.8 +/- 13.0% during contralateral tilt. The duration of the early (ESP1) and late (ESP2) silent periods was also affected: during ipsilateral tilt ESP1 and ESP2 duration increased to 130.0 +/- 3.5% and to 122.1 +/- 2.1% of control, respectively; during contralateral tilt it was reduced to 76.8 +/- 1.2% and to 83.0 +/- 1.7% of control, respectively. On the contrary, changes in latencies were not significant. These data evidenced an asymmetrical effect exerted on trigeminal motor activity by static tilt. Since the influence of all receptors which could be activated by static tilt, except that arising from the macular ones, was minimized in this study, it is likely that the observed effects, induced by static tilt on masseter muscle activity, were of macular origin.     

Spatial and Temporal Deposition of Adhesive Extracellular Polysaccharide Capsule and Fimbriae by Hyphomonas Strain MHS-3

Hyphomonas strain MHS-3, a member of a genus of primary colonizers of surfaces immersed in marine water, synthesizes two structures that mediate adhesion to solid substrata, namely, capsular exopolysaccharide and fimbriae. Specific stains, gold-labelled lectins, and monoclonal antibodies, along with transmission electron microscopy of synchronized populations, revealed that both structures are polarly and temporally expressed. The timed synthesis and placement of the fimbriae and capsule correlated with the timing and locus of MHS-3 adhesion.     

Nitrogen distribution and leaf area indices in relation to photosynthetic nitrogen use efficiency in savanna grasses

Leaf photosynthetic characteristics, distribution patterns of nitrogen content per unit leaf area (n_L) and leaf area production per unit n_Lwere measured in natural stands of a C₄ grass (Hyparrhenia rufa) from the seasonal savannas and of a C₄grass (Paspalum fasciculatum) and two C₃grasses (Leersia hexandra and Hymenachne amplexicaulis) from the flooded savannas in central Venezuela. Daily rates of canopy photosynthesis (P_cD) as well as the optimal leaf area production per unit n_Lat which P_cDfor a given total amount of nitrogen in the canopy (i.e., canopy-PNUE) is maximized were also calculated. The C₃and C₄species from the flooded savannas had similar light saturated rates of photosynthesis per unit n_L(i.e. leaf-PNUE) and similar canopy-PNUEs which was in strong contrast with previous studies. Especially H. rufa but also L. hexandra and H. amplexicaulis had leaf- and canopy-PNUEs which were considerably higher than the values calculated for most other species with the same photosynthetic pathway (i.e., C₃or C₄). In contrast to previous studies, differences in the light gradient in the canopy between stands only partially explained differences in N distribution. Measured leaf area indices were greater and the average n_L values were consequently smaller than the calculated optima. There was, however, a very strong linear correlation between the optimal and actual average n_Lindicating that even though the model overestimated average n_L, it did predict the differences in leaf area production per unit nitrogen – the inverse average n_L– very well. This result strongly indicates that leaf area production per unit of leaf nitrogen increases with leaf-PNUE and decreases with the extinction coefficient for light. Grass species from seasonal savannas have extremely high leaf-PNUEs and thus optimally produce large amounts of leaf area per unit n_L. This helps explain how stands of these species may have high leaf area indices and achieve high photosynthetic productivity despite the very low nutrient availability at which they grow.     

Cardiac myofilament regulation by protein phosphatase type 1alpha and CapZ.

Myofilament regulation by protein kinases is well characterized, but relatively little is known about protein phosphatase control of myofilaments. Increased protein phosphatase type 1 (PP1) activity observed in failing hearts underscores the need for investigation of this intracellular signal, including the elements that regulate its activity. The Z-disc protein CapZ controls protein kinase C (PKC) regulation of cardiac myofilaments, but whether this effect is specific to PKC, or CapZ plays a general role in intracellular signalling, is not known. We sought to determine how the alpha isoform of PP1 (PP1alpha) regulates murine cardiac myofilaments and whether CapZ influences PP1alpha-dependent regulation of cardiac myofilaments. Immunoblot analysis showed PP1alpha binding to cardiac myofilaments. Exogenous PP1alpha increased myofilament Ca2+ sensitivity and maximal actomyosin Mg2+-ATPase activity while dephosphorylating myosin binding protein C, troponin T, troponin I, and myosin light chain 2. Extraction of CapZ decreased myofilament-associated PP1alpha and attenuated the effects of PP1alpha on myofilament activation. PP1alpha-dependent dephosphorylation of myofilament proteins was reduced with CapZ extraction, except for troponin I. Extracting CapZ after PP1alpha treatment allowed most of the PP1alpha-dependent effects on myofilament activation to remain, indicating that CapZ removal modestly desensitizes cardiac myofilaments to dephosphorylation. Our results demonstrate myofilament regulation by PP1alpha and support the concept that cardiac Z-discs are vital components in intracellular signalling.     

Tensor GSVD of Patient- and Platform-Matched Tumor and Normal DNA Copy-Number Profiles Uncovers Chromosome Arm-Wide Patterns of Tumor-Exclusive Platform-Consistent Alterations Encoding for Cell Transformation and Predicting Ovarian Cancer Survival

The number of large-scale high-dimensional datasets recording different aspects of a single disease is growing, accompanied by a need for frameworks that can create one coherent model from multiple tensors of matched columns, e.g., patients and platforms, but independent rows, e.g., probes. We define and prove the mathematical properties of a novel tensor generalized singular value decomposition (GSVD), which can simultaneously find the similarities and dissimilarities, i.e., patterns of varying relative significance, between any two such tensors. We demonstrate the tensor GSVD in comparative modeling of patient- and platform-matched but probe-independent ovarian serous cystadenocarcinoma (OV) tumor, mostly high-grade, and normal DNA copy-number profiles, across each chromosome arm, and combination of two arms, separately. The modeling uncovers previously unrecognized patterns of tumor-exclusive platform-consistent co-occurring copy-number alterations (CNAs). We find, first, and validate that each of the patterns across only 7p and Xq, and the combination of 6p+12p, is correlated with a patient’s prognosis, is independent of the tumor’s stage, the best predictor of OV survival to date, and together with stage makes a better predictor than stage alone. Second, these patterns include most known OV-associated CNAs that map to these chromosome arms, as well as several previously unreported, yet frequent focal CNAs. Third, differential mRNA, microRNA, and protein expression consistently map to the DNA CNAs. A coherent picture emerges for each pattern, suggesting roles for the CNAs in OV pathogenesis and personalized therapy. In 6p+12p, deletion of the p21-encoding CDKN1A and p38-encoding MAPK14 and amplification of RAD51AP1 and KRAS encode for human cell transformation, and are correlated with a cell’s immortality, and a patient’s shorter survival time. In 7p, RPA3 deletion and POLD2 amplification are correlated with DNA stability, and a longer survival. In Xq, PABPC5 deletion and BCAP31 amplification are correlated with a cellular immune response, and a longer survival.     

First-In-Human,Double-Blind,Placebo-Controlled,Randomized, Dose-Escalation Study of BG00010, a Glial Cell Line-Derived Neurotrophic Factor Family Member,in Subjects with Unilateral Sciatica

ObjectiveTo evaluate the safety, tolerability, and pharmacokinetics of single doses of BG00010 (neublastin, artemin, enovin) in subjects with unilateral sciatica.MethodsThis was a single-center, blinded, placebo-controlled, randomized Phase 1 sequential-cohort, dose-escalation study (ClinicalTrials.gov identifier {"type":"clinical-trial","attrs":{"text":"NCT00961766","term_id":"NCT00961766"}}NCT00961766; funded by Biogen Idec). Adults with unilateral sciatica were enrolled at The Royal Adelaide Hospital, Australia. Four subjects were assigned to each of eleven cohorts (intravenous BG00010 0.3, 1, 3, 10, 25, 50, 100, 200, 400, or 800 μg/kg, or subcutaneous BG00010 50 μg/kg) and were randomized 3:1 to receive a single dose of BG00010 or placebo. The primary safety and tolerability assessments were: adverse events; clinical laboratory parameters and vital signs; pain as measured by a Likert rating scale; intra-epidermal nerve fiber density; and longitudinal assessment of quantitative sensory test parameters. Blood, serum, and plasma samples were collected for pharmacokinetic and pharmacodynamic assessments. Subjects were blinded to treatment assignment throughout the study. The investigator was blinded to treatment assignment until the Data Safety Review Committee review of unblinded data, which occurred after day 28.ResultsBeyond the planned enrollment of 44 subjects, four additional subjects were enrolled into to the intravenous BG00010 200 μg/kg cohort after one original subject experienced mild generalized pruritus. Therefore, a total of 48 subjects were enrolled between August 2009 and December 2011; all were included in the safety analyses. BG00010 was generally well tolerated: in primary analyses, the most common treatment-emergent adverse events were changes in temperature perception, pruritus, rash, or headache; no trends were observed in clinical laboratory parameters, vital signs, intra-epidermal nerve fiber density, or quantitative sensory testing. BG00010 was not associated with any clear, dose-dependent trends in Likert pain scores. BG00010 was rapidly distributed, with a prolonged terminal elimination phase.ConclusionsThese data support the development of BG00010 for the treatment of neuropathic pain.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT00961766","term_id":"NCT00961766"}}NCT00961766