White Bars Research Articles

Artifact-reduced simultaneous MRI of multiple rats with liver cancer using PROPELLER

To explore simultaneous magnetic resonance imaging (MRI) for multiple hepatoma-bearing rats in a single session suppressing motion- and flow-related artifacts to conduct preclinical cancer research efficiently. Our institutional Animal Experimental Committee approved this study. We acquired PROPELLER (periodically rotated overlapping parallel lines with enhanced reconstruction) T2 - and diffusion-weighted images of the liver in one healthy and 11 N1-S1 hepatoma-bearing rats in three sessions using a 3-T clinical scanner and dedicated multiarray coil. We compared tumor volumes on MR images and those on specimens, evaluated apparent diffusion coefficients (ADC) of the tumor, and compared them to previously reported values. Each MRI session took 39-50 minutes from anesthesia induction to the end of scans for four rats (10-13 minutes per rat). PROPELLER provided artifact-reduced T2 - and diffusion-weighted images of the rat livers. Tumor volumes on MR images ranged from 0.04-1.81 cm(3) and were highly correlated with those on specimens. The ADC was 1.57 ± 0.37 × 10(-3) mm(2) /s (average ± SD), comparable to previously reported values. PROPELLER allowed simultaneous acquisition of artifact-reduced T2 - and diffusion-weighted images of multiple hepatoma-bearing rats. This technique can promote high-throughput preclinical MR research for liver cancer.

Glycemic response in healthy rats fed with composite cereal bars

AbstractThree composite cereal bars containing white maize, blue maize, or unripe banana flours were prepared. The glycemic response in rats feed with a dose available carbohydrates, and the bars effect on a glucose tolerance test were evaluated. A dose of 0.85 g/kg was used in the experiments with the three bars. The experiment with a glucose load showed that rats previously fed with blue maize and unripe banana bars showed reduced glycemic response, probably as consequence of glucose entrapment within the food matrix and produce a slow release. The effect was more pronounced for the unripe banana bar. The groups fed with equivalent load of available carbohydrates from the various bars exhibited lower and slower glycemic responses than a control group administered only with a glucose load. The white maize bar elicited a maximal blood glucose level at 30 min postprandial, blue maize at 45 min and unripe banana bar at 60 min. Bars inducing variable glycemic response may be prepared following the proper choice of functional ingredients.

The Amphiphilic Oxygen Carrier Perfluorohexyloctane Improves Oxygenation of Ischemic Pig Pancreases and Increases the Quality of Isolated Islets Compared to Perfluorodecalin

Introduction: Ischemia is one of the most critical variables for success or failure of islet isolation and islet transplantation. Prolonged cold storage is associated with reduced yield and decreased viability of isolated islets. Technical equipment for continuous vascular oxygen supply during cold storage of retrieved organs is expensive and requires trained personnel for operation. In the present study we assessed the efficiency of the amphiphilic compound perfluorohexyloctane (F6H8) to provide oxygen during static cold storage of pancreases retrieved from adult non-heartbeating pigs for subsequent islet isolation. Methods: Pancreases (n=10) were explanted after 15 min of warm ischemia and dissected ex-situ into the connecting and spleenic lobe. After intraductal perfusion with cold UW-solution the pancreatic segments were immersed in oxygen-precharged F6H8 or perfluorodecalin (PFD) and stored on ice for 9-10 hours until processing for islet isolation and purification. After culture at 37°C for 2-3 days islets were subjected to extensive quality assessment. All data are presented as mean ± SEM and were analysed by Wilcoxon test. Results: Pancreatic segments stored in oxygen-precharged F6H8 had a significantly higher intrapancreatic pO2 compared to preoxygenated PFD (10.1±3.9 vs. 1.6±1.1 mm Hg, p< 0.05). This finding corresponds to the significantly increased ATP content in islets isolated from segments stored in F6H8 (290±60 vs 203±31 pg/ng DNA, p< 0.01). Although freshly isolated islet yield per gram trimmed tissue did not significantly differ between F6H8 and PFD (3020±330 vs. 2940±270 IEQ/g) significantly more islets were recovered after culture when isolated from F6H8-stored lobes (57±6 vs. 39±6%, p< 0.01). Lower viability (76±3 vs. 82±3%, p< 0.05) measured in islets after PFD storage correlated with their inability to downregulate insulin release after switching from high (20 mmol/L) to basal (2 mmol/L) glucose concentration during static glucose incubation (Fig. 1).[Figure 1]Figure 1. Insulin release of islets isolated from ischemic porcine pancreatic segments after 9-10 hours of cold storage in oxygenprecharged PFD or F6H8. Islets were sequentially stimulated by 2 (white bars), 20 (grey bars) and again 2 mmol/L of glucose. *p< 0.05, **p< 0.01 as indicated. Conclusions: In the case that pig races, suitable for successful islet isolation, are locally not available, pancreas preservation for subsequent islet isolation can be significantly improved utilizing oxygen-precharged F6H8 for organ shipment. The same applies if pathogen-free pig pancreases have to be processed in institutions highly experienced in pig islet isolation.

Contribution of Hematopoietically-Derived Progenitors to the Central Nervous System in Mixed Chimeric Mice

Introduction: Microglia are resident immune cells of the central nervous system (CNS) and work to maintain a homeostatic environment to allow for proper neuronal functioning. Previous studies suggest microglia originate both from a neural progenitor cell population and possibly a myeloid progenitor. This study aims to establish a working model to both quantitatively and qualitatively determine the contribution of hematopoietically-derived myeloid precursors to the CNS microglia population in a non-disease state. Methods: Normal C57BL/6 mice were treated with Busulfan (150mg/10g weight; days -2 & -1) followed by administration of syngeneic green fluorescent protein (GFP+) positive bone marrow cells (1× and 20×106) to create hematopoietic chimeras. Peripheral chimerism in the blood was assessed at 24 hours, 48 hours, and biweekly post bone marrow transplant (BMT) using flow cytometric analysis. Mice were saline perfused, brains extracted and split along the midsagittal plane to allow for both flow cytometic analysis and immunoflourescent imaging of each animal at 48 hours, and one, seven, eighteen and twenty-four weeks post BMT. 30μm tissue sections were obtained with a freezing microtome and microglia were identified with anti-mouse Iba-1 primary and Alexa Fluor 594 fluorescent secondary antibodies. Results: By four weeks post-BMT, stable peripheral chimerism was established across multiple cell lineages, including greater than 90% GFP+ donor cells in the myeloid lineages. Both flow cytometric and immunoflourescent data demonstrate that GFP+ donor cells contribute to the CNS by seven weeks post-BMT, as seen by the appearance of GFP+ cells within the Mac1+ CD45mid population (˜3-5%). Figure 1 presents immunofluorescent staining of week 7 brain tissue within the left prefrontal cortex of a chimeric mouse: Panel A represents Iba-1+ labeled microglia cells; Panel B represents GFP+ cells; and Panel C represents a merged image showing double positive cells in yellow as the newly infiltrated donor-derived microglia. White scale bars represent 50μm.Figure: [Iba1+ GFP+ in mixed chimera]Conclusion: This study demonstrates a novel experimental model that utilizes a non-irradiation conditioning protocol to establish chimerism and allows for simultaneous quantitative and qualitative analysis of the microglia population within the CNS tissue. These data demonstrate by both flow cytometric and immunofluorescent analysis that hematopoietically-derived progenitors can contribute to the CNS, and may appear as early as seven weeks post-BMT.

Studying the Tailgating Issues and Exploring Potential Treatment

A human factors study consisting of a vehicle headway analysis and a questionnaire survey was conducted in Rhode Island (RI) to investigate tailgating issues and possible means for tailgating treatment. Vehicle headways were collected from highway surveillance videos and serious tailgating issues were identified on RI highways. The results of the questionnaire survey further confirmed the observations made in the vehicle headway analysis that most RI drivers maintained insufficient vehicle headways on highways. Among a few tailgating treatments presented in the survey, most subjects preferred a system consisting of equally spaced, white horizontal bars marked on pavement and overhead graphic-aided dynamic message signs.

Ciguatoxins activate specific cold pain pathways to elicit burning pain from cooling

Ciguatoxins are sodium channel activator toxins that cause ciguatera, the most common form of ichthyosarcotoxism, which presents with peripheral sensory disturbances, including the pathognomonic symptom of cold allodynia which is characterized by intense stabbing and burning pain in response to mild cooling. We show that intraplantar injection of P-CTX-1 elicits cold allodynia in mice by targeting specific unmyelinated and myelinated primary sensory neurons. These include both tetrodotoxin-resistant, TRPA1-expressing peptidergic C-fibres and tetrodotoxin-sensitive A-fibres. P-CTX-1 does not directly open heterologously expressed TRPA1, but when co-expressed with Na(v) channels, sodium channel activation by P-CTX-1 is sufficient to drive TRPA1-dependent calcium influx that is responsible for the development of cold allodynia, as evidenced by a large reduction of excitatory effect of P-CTX-1 on TRPA1-deficient nociceptive C-fibres and of ciguatoxin-induced cold allodynia in TRPA1-null mutant mice. Functional MRI studies revealed that ciguatoxin-induced cold allodynia enhanced the BOLD (Blood Oxygenation Level Dependent) signal, an effect that was blunted in TRPA1-deficient mice, confirming an important role for TRPA1 in the pathogenesis of cold allodynia.

Human phase response curve to a 1 h pulse of bright white light

The phase resetting response of the human circadian pacemaker to light depends on the timing of exposure and is described by a phase response curve (PRC). The current study aimed to construct a PRC for a 1 h exposure to bright white light (∼8000 lux) and to compare this PRC to a <3 lux dim background light PRC. These data were also compared to a previously completed 6.7 h bright white light PRC and a <15 lux dim background light PRC constructed under similar conditions. Participants were randomized for exposure to 1 h of either bright white light (n=18) or <3 lux dim background light (n=18) scheduled at 1 of 18 circadian phases. Participants completed constant routine (CR) procedures in dim light (<3 lux) before and after the light exposure to assess circadian phase. Phase shifts were calculated as the difference in timing of dim light melatonin onset (DLMO) during pre- and post-stimulus CRs. Exposure to 1 h of bright white light induced a Type 1 PRC with a fitted peak-to-trough amplitude of 2.20 h. No discernible PRC was observed in the <3 lux dim background light PRC. The fitted peak-to-trough amplitude of the 1 h bright light PRC was ∼40% of that for the 6.7 h PRC despite representing only 15% of the light exposure duration, consistent with previous studies showing a non-linear duration–response function for the effects of light on circadian resetting.

Impairment of GABAB receptor dimer by endogenous 14-3-3ζ in chronic pain conditions

In the central nervous system, the inhibitory GABAB receptor is the archetype of heterodimeric G protein-coupled receptors (GPCRs). However, the regulation of GABAB dimerization, and more generally of GPCR oligomerization, remains largely unknown. We propose a novel mechanism for inhibition of GPCR activity through de-dimerization in pathological conditions. We show here that 14-3-3ζ, a GABAB1-binding protein, dissociates the GABAB heterodimer, resulting in the impairment of GABAB signalling in spinal neurons. In the dorsal spinal cord of neuropathic rats, 14-3-3ζ is overexpressed and weakens GABAB inhibition. Using anti-14-3-3ζ siRNA or competing peptides disrupts 14-3-3ζ/GABAB1 interaction and restores functional GABAB heterodimers in the dorsal horn. Importantly, both strategies greatly enhance the anti-nociceptive effect of intrathecal Baclofen in neuropathic rats. Taken together, our data provide the first example of endogenous regulation of a GPCR oligomeric state and demonstrate its functional impact on the pathophysiological process of neuropathic pain sensitization.

Factor H-related Protein 4 Activates Complement by Serving as a Platform for the Assembly of Alternative Pathway C3 Convertase via Its Interaction with C3b Protein

Human complement factor H-related protein (CFHR) 4 belongs to the factor H family of plasma glycoproteins that are composed of short consensus repeat (SCR) domains. Although factor H is a well known inhibitor of the alternative complement pathway, the functions of the CFHR proteins are poorly understood. CFHR4 lacks SCRs homologous to the complement inhibitory domains of factor H and, accordingly, has no significant complement regulatory activities. We have previously shown that CFHR4 binds C-reactive protein via its most N-terminal SCR, which leads to classical complement pathway activation. CFHR4 binds C3b via its C terminus, but the significance of this interaction is unclear. Therefore, we set out to clarify the functional relevance of C3b binding by CFHR4. Here, we report a novel role for CFHR4 in the complement system. CFHR4 serves as a platform for the assembly of an alternative pathway C3 convertase by binding C3b. This is based on the sustained ability of CFHR4-bound C3b to bind factor B and properdin, leading to an active convertase that generates C3a and C3b from C3. The CFHR4-C3bBb convertase is less sensitive to the factor H-mediated decay compared with the C3bBb convertase. CFHR4 mutants containing exchanges of conserved residues within the C-terminal C3b-binding site showed significantly reduced C3b binding and alternative pathway complement activation. In conclusion, our results suggest that, in contrast to the complement inhibitor factor H, CFHR4 acts as an enhancer of opsonization by promoting complement activation.

Thermoreversible Hyaluronan Hydrogels Support Mesenchymal Stem Cells Discogenic Differentiation in Vitro and Ex Vivo

Introduction Hyaluronan is a proteoglycan widely present in the nucleus pulposus (NP) of the intervertebral disk (IVD). Recently, thermoreversible hyaluronan (HA) based hydrogels, which are injectable, minimally invasive, allow for encapsulation and maintenance of viable cells and promote re-differentiation of NP cells, have been developed.1 While it is known that hyaluronan is recognized by mesenchymal stem cells (MSCs)2 and can induce anabolic pathways, growth factors may further support MSC differentiation in HA-based hydrogels. Therefore, the objectives of the present work were: (i) to assess whether the addition of growth factors3 could support MSC differentiation towards the disk cell phenotype in HA based hydrogels and (ii) to determine if MSC preconditioning (culture under “chondrogenic” conditions) would improve the survival rate and differentiation potential of MSC supplemented to an IVD cultured ex vivo. Materials and Methods Hydrogel Thermoreversible HA-based hydrogels were prepared by grafting a thermoreversible segment poly (N-isopropylacrylamide) (pNIPAM) on a functionalized HA backbone, as previously described.1 In vitro Human bone marrow-derived MSCs (P2-P4) were cultured for 7 days in HA-pNIPAM hydrogel under hypoxic conditions (5% O2) in chondrogenic medium, with or without recombinant human growth and differentiation factor-5 (rhGDF-5) supplementation. Cell viability, DNA, and glycosaminoglycans (GAG) content were quantified by Live-dead, Picogreen, and 1,9 dimethylmethylene blue assays, respectively. Gene expression analysis was performed to assess the disc-like differentiation of MSCs. The expression of collagen type I and II (COL1 and COL2) aggrecan (ACAN), cytokeratin-19, sox-9, cluster of differentiation 24 (CD24), hyaluronan synthase I and II (HAS1 and HAS2), forkhead box protein F1 (FOXF1) and carbonic anhydrase 12 (CA12) was analyzed with 18s as endogenous control. Ex Vivo Bovine caudal IVDs were excised and nucleotomy performed through the endplate (Fig. 1A,B). MSCs were either suspended in HA-pNIPAM and directly supplied to the IVDs or precultured (under hypoxic conditions and with supplementation of GDF-5) for 1 week in HA-pNIPAM and then supplied to the IVDs. After 1 week of culture, gene expression analyses were performed using the same markers as for the in vitro study. Statistics After confirming the normality of the data distribution, one-way analysis of variance with Bonferroni posthoc was performed ( p &lt; 0.05). Results MSC viability was maintained&gt;90% over 1 week of culture in the HA-pNIPAM hydrogel both in vitro and ex vivo. DNA and GAG did not show significant variation over the 7 days of in vitro culture. Gene expression revealed 10–100-fold upregulation of the transcription factor SOX9 and 100–1000, fold upregulation of COL2, while COL1 was only slightly enhanced. The expression of the potential NP cell marker KRT19 was also increased. With the addition of rhGDF-5, an improved COL2/COL1 expression ratio was found. No significant differences were found for the other genes. Ex vivo cultures of nucleotomized discs supplemented with MSCs in HA-pNIPAM confirmed the positive effect of the hydrogel and the IVD environment on MSC differentiation towards the disc-like phenotype (Fig. 1C), with upregulation of collagen type II ( p &lt; 0.05), CD24, and FOX-F1. No significant differences were found for the other genes. Preculture of MSCs before the supplementation in the IVD did not enhance MSC differentiation. Figure 1 Bovine IVD after nucleotomy: (A) top view and (B) view of the nucleotomized area. (C) Gene expression of human MSCs after 1 week of culture in bovine IVDs normalized to the mRNA levels at day 0 of culture: human MSCs were either suspended in HA-pNIPAM and directly supplied to bovine IVDs (white bars) or precultured for 1 week in HA-pNIPAM hydrogel and then supplied to bovine IVDs (grey bars);* p &lt; 0.05, outliers. Conclusion The thermoreversible hyaluronan-based hydrogel was able to induce human MSC differentiation toward a “disc-like” phenotype without the addition of growth factors, although GDF-5 supplementation resulted in an improved gene expression profile. Preculture of MSCs before the supplementation in the IVD is not required with the thermoreversible hyaluronan-based hydrogel. Therefore, this type of hydrogel could be an appropriate carrier for MSCs supplementation to compromised discs. Investigations are ongoing to evaluate its biomechanical behavior under loading. Acknowledgements This study was partially supported by a NASS Research Grant. I confirm having declared any potential conflict of interest for all authors listed on this abstract Yes Disclosure of Interest None declared Peroglio M, et al. European Spine Journal (Epub ahead of print) Zhu H et al. Stem cells 2006; 24:928–935 Gantenbein-Ritter B, et al. European Spine Journal 2011;20(6):962–971

Spectrum of threats to nests of Yellow-wattled Lapwing Vanellus malabaricus in Kurukshetra outskirts-a case study

It is one thing that Red-wattled Lapwing Vanellus indicus is, rather a common bird on the outskirts of wheat harvested fields in outskirts of Kurukshetra, yet, Yellow-wattled Lapwing V. malabaricus (Boddaert, 1783) is an uncommon bird and seen rarely and that too with efforts and serious search. On the top of this, the bird is confronting most difficult conditions for its even rare existence. It is characterized by the presence of bright Yellow fleshy lappets above and in front of eyes. Black wings show off a white bar in flight. It has a little shorter staturecompared with that of Red-wattled Lapwing. Yellow-wattled Lapwing is available in only very specific spots like Sushant City, Harman City and Sector-8 in isolated conditions as single, double or 6-8 in Kurukshetra environs. Only one nest of Yellow-wattled Lapwing was observed on 28 April, 2011 in Sushant city in Kurukshetra. The nest was stuffed with straws and not by Pebbles. The clutch size was 4. It is pertinent to mention that all the four eggs hatched successfully on 24-25 May, 2011. Present observations suggest its’ alarming destruction in the last 5-8 years (2003-11). Now it has been pushed in a very delicate position wherefrom its extinction in a silent manner is sure, sooner than latter.

Review of Case-Mix Corrected Survival Curves

Survival is an end point of immense interest in cardiothoracic research. In observational studies, the comparison of survival between groups of patients is usually accomplished using a toolbox that includes Kaplan-Meier survival curves and the Cox model. The Cox model yields comparisons between groups adjusted for case-mix differences, whereas the Kaplan-Meier is a plot of survival over time without adjustment. During the past decade, new methods have emerged for case-mix adjustment of survival curves and are increasingly being used in cardiothoracic research. The purpose of this report is to describe, illustrate, and review several approaches to case-mix adjusted survival (or event-free) curves.

An Abnormally Colored Redbanded Rockfish, Sebastes babcocki

Four species of eastern North Pacific rockfishes of the genus Sebastes are easily distinguished from their congeners by the coloration characteristic of broad lateral banding. These species are the Tiger Rockfish, S. nigrocinctus; Treefish, S. serriceps; Flag Rockfish, S. rubrivinctus; and Redbanded Rockfish, S. babcocki. These species are shown to be closely related and have been placed in the Sebastichthys clade by Hyde and Vetter (2007). The Tiger Rockfish and Treefish are distinguished by differences in their general body form and coloration of the banding pattern. The Treefish invariably exhibits alternating black, brown, or dark green and yellow bars, and the lips are distinctly pink to red (rarely without coloration). The Tiger Rockfish manifests greater variation in banding with the darker bars being primarily red, but can vary from reddish-black to reddish-brown. The alternating lighter bars are mainly white, but occasionally show a reddish hue. The Flag and Redbanded rockfishes possess alternating red and white bars (Love et al., 2002). The general similarity in body shape and color pattern between the latter two species was cause for them to be considered conspecific from shortly after the year of description of S. babcocki (Thompson, 1915) until Rosenblatt and Chen (1972) clarified the distinction of these species and pointed out a number of meristic and morphological characteristics that definitively separate these two species. The Flag Rockfish was described in the late 1800’s (Jordan and Gilbert, 1880). On 10 February 2004, a uniformly red rockfish (Fig. 1) was encountered by Diane Haas, then a Fishery Technician with the Pacific States Marine Fisheries Commission, during routine sampling of commercial groundfishes. The F/V Alex Kevin D had unloaded three market categories of groundfishes: Longspine Thornyhead, Sebastolobus altivelis; Shortspine Thornyhead, S. alascanus; and Blackgill Rockfish, Sebastes melanostomus, which were to be sampled. The uniformly red rockfish was included in the Blackgill Rockfish market category, where a 50 pound cluster was randomly selected from a total landing of 764 pounds. The species composition of the cluster consisted of Blackgill Rockfish, one Rosethorn Rockfish, S. helvomaculatus, and the uniformly red rockfish. Also present in the landing, but not included in the sample, were at least two Rougheye Rockfish, S. aleutianus, (from California the species is now considered as Blackspotted Rockfish, Sebastes melanostictus [Orr and Hawkins, 2008]). The fishes were taken in Monterey Bay (ca. 36u479 N, 122u079 W) by commercial longline gear on the continental slope at a depth of 200–260 fathoms (366–475 meters). The red rockfish was not immediately identifiable with any of the red-colored, outer shelf-upper slope rockfishes normally encountered off central California and was Bull. Southern California Acad. Sci. 111(1), 2012, pp. 22–24 E Southern California Academy of Sciences, 2012

Phagosomes Induced by Cytokines Function as anti-Listeria Vaccines

Phagosomes are critical compartments for innate immunity. However, their role in the protection against murine listeriosis has not been examined. We describe here that listericidal phago-receptosomes are induced by the function of IFN-γ or IL-6 as centralized compartments for innate and adaptive immunity because they are able to confer protection against murine listeriosis. These phago-receptosomes elicited LLO(91-99)/CD8(+)- and LLO(189-201)/CD4(+)-specific immune responses and recruited mature dendritic cells to the vaccination sites controlled by T cells. Moreover, they present exceptional features as efficient vaccine vectors. First, they compartmentalize a novel listericidal STAT-1-mediated signaling pathway that confines multiple innate immune components to the same environment. Second, they show features of MHC class II antigen-loading competent compartments for cathepsin-D-mediated LLO processing. Third, murine cathepsin-D deficiencies fail to develop protective immunity after vaccination with listericidal phago-receptosomes induced by IFN-γ or IL-6. Therefore, it appears that the connection of STAT-1 and cathepsin-D in a single compartment is relevant for protection against listeriosis.

Comparison of Additional Versus No Additional Heparin During Therapeutic Oral Anticoagulation in Patients Undergoing Percutaneous Coronary Intervention

Uninterrupted oral anticoagulation (OAC) therapy can be the preferred strategy in patients with atrial fibrillation at moderate to high risk of thromboembolism undergoing percutaneous coronary intervention (PCI). To evaluate the need for additional heparins in addition to therapeutic peri-PCI OAC, we assessed bleeding complications and major adverse cardiac and cerebrovascular events in 414 consecutive patients undergoing PCI during therapeutic (international normalized ratio 2 to 3.5) periprocedural OAC. Patients were divided into those with no (n = 196) and with (n = 218) additional use of periprocedural heparins. No differences in major adverse cardiac and cerebrovascular events (4.1% vs 3.2%, p = 0.79) or major bleeding (1.0% vs 3.7%, p = 0.11) were detected, but access site complications (5.1% vs 11.0%, p = 0.032) were less frequent in those without additional heparins. When adjusted for propensity score, patients with additional heparins had a higher risk of access site complications (odds ratio 2.6, 95% confidence interval 1.1 to 6.1, p = 0.022) without any increased risk of any other adverse event. Analysis of 1-to-1 propensity-matched pairs showed a significantly higher risk of access site complication in patients receiving additional AC (13.1% vs 5.7%, p = 0.049). In conclusion, therapeutic warfarin treatment seems to provide sufficient AC for PCI. Additional heparins are not needed and may increase access site complications.

The upright posture improves plantar stepping and alters responses to serotonergic drugs in spinal rats

Recent studies on the restoration of locomotion after spinal cord injury have employed robotic means of positioning rats above a treadmill such that the animals are held in an upright posture and engage in bipedal locomotor activity. However, the impact of the upright posture alone, which alters hindlimb loading, an important variable in locomotor control, has not been examined. Here we compared the locomotor capabilities of chronic spinal rats when placed in the horizontal and upright postures. Hindlimb locomotor movements induced by exteroceptive stimulation (tail pinching) were monitored with video and EMG recordings. We found that the upright posture alone significantly improved plantar stepping. Locomotor trials using anaesthesia of the paws and air stepping demonstrated that the cutaneous receptors of the paws are responsible for the improved plantar stepping observed when the animals are placed in the upright posture.We also tested the effectiveness of serotonergic drugs that facilitate locomotor activity in spinal rats in both the horizontal and upright postures. Quipazine and (±)-8-hydroxy-2-(dipropylamino)tetralin hydrobromide (8-OH-DPAT) improved locomotion in the horizontal posture but in the upright posture either interfered with or had no effect on plantar walking. Combined treatment with quipazine and 8-OH-DPAT at lower doses dramatically improved locomotor activity in both postures and mitigated the need to activate the locomotor CPG with exteroceptive stimulation. Our results suggest that afferent input from the paw facilitates the spinal CPG for locomotion. These potent effects of afferent input from the paw should be taken into account when interpreting the results obtained with rats in an upright posture and when designing interventions for restoration of locomotion after spinal cord injury.

In Vitro and In Vivo Proof of Tolerance After Two-Step Haploidentical Bone Marrow and Kidney Transplantation of the Same Donor

In Vitro and In Vivo Proof of Tolerance After Two-Step Haploidentical Bone Marrow and Kidney Transplantation of the Same Donor

Cohesin-SA1 deficiency drives aneuploidy and tumourigenesis in mice due to impaired replication of telomeres

Cohesin is a protein complex originally identified for its role in sister chromatid cohesion, although increasing evidence portrays it also as a major organizer of interphase chromatin. Vertebrate cohesin consists of Smc1, Smc3, Rad21/Scc1 and either stromal antigen 1 (SA1) or SA2. To explore the functional specificity of these two versions of cohesin and their relevance for embryonic development and cancer, we generated a mouse model deficient for SA1. Complete ablation of SA1 results in embryonic lethality, while heterozygous animals have shorter lifespan and earlier onset of tumourigenesis. SA1-null mouse embryonic fibroblasts show decreased proliferation and increased aneuploidy as a result of chromosome segregation defects. These defects are not caused by impaired centromeric cohesion, which depends on cohesin-SA2. Instead, they arise from defective telomere replication, which requires cohesion mediated specifically by cohesin-SA1. We propose a novel mechanism for aneuploidy generation that involves impaired telomere replication upon loss of cohesin-SA1, with clear implications in tumourigenesis.

Visual responsiveness of central-complex neurons in the desert locust Schistocerca gregaria

Event Abstract Back to Event Visual responsiveness of central-complex neurons in the desert locust Schistocerca gregaria Tobias Bockhorst1*, Ronny Rosner1 and Uwe Homberg1 1 Philipps-University Marburg, Biology, Germany The central complex is a set of midline-spanning neuropils in the insect brain playing an increasingly apparent role in motor control and visual integration, particularly visual object discrimination, visual place learning, and spatial orientation (1-4). In the desert locust, central-complex neurons were shown to represent the electric field vector of polarized light in a polarotopic gradient which may act as a sky compass for navigation during long-distance migrations (5,6). We performed intracellular recordings with subsequent tracer injections to measure the responsiveness of polarization-sensitive and other identified central-complex neurons to a variety of unpolarized light signals displayed in the left medio-lateral visual field. Flashes of different spectral composition served to test general light sensitivity while a variety of object-like light patterns was used to screen for more complex spatio-temporal tuning. Patterns most frequently presented comprise white or black bars varied in length and edge orientation, displayed either stationary or translating. The trajectory of translating bars and its relation to edge orientation were altered as well. In central-complex neurons hitherto encountered, stimulus correlated changes in spiking pattern ranged from stereotypical light responses to more complex and subtle modulations that appeared indicative of movement sensitivity or tuning to object positions. Additional data and further analysis is required to assess the consistency of these putative responses as well as their distance to occasionally complex background activity. In contrast, complementary recordings from optic-lobe- and descending neurons invading the medial protocerebrum showed substantially stronger and more reliable responses which confirms that these stimuli are generally adequate for the locust visual system and might be of behavioral significance. It remains to be shown whether central-complex neurons are involved in processing visual stimuli as applied in the present account or largely bypassed to establish more direct pathways for mediating fast behavioral responses.

Malignant mesothelioma in Metsovo, Greece, from domestic use of asbestos: 30 years later

To the Editors: Malignant mesothelioma (MM) is a devastating disease, almost exclusively due to inhalation of asbestos fibres, and with higher risk for amphiboles [1]. Mediterranean regions, such as Turkey, Cyprus and Corsica, and others, such as New Caledonia [2], have experienced epidemics of MM as a result of nonoccupational, “domestic” exposure to tremolite asbestos and fibrous erionite [3]. In 1987, we reported on the very high incidence, 300 times higher than expected, of MM in the area of Metsovo, a complex of small villages in the prefecture of Ioannina in north-west Greece [4]. This, in conjunction with the previously noted very frequent pleural calcifications among Metsovites [5], led to the discovery of the culprit, a tremolite asbestos-containing whitewash (“luto” in the local dialect) [6]. The material was used by practically all households until 1940–1950. After that, it was gradually substituted by modern materials that did not contain asbestos. In 1980, luto was used by only 18% of builders and by 1990 it had been abandoned altogether (fig. 1) [7]. In 1996, we reported that the incidence of MM in the period 1985–1994 declined to one-third compared with the period 1980–1984, and we attributed the reduction to the abandonment of the use of luto. As a result, we concluded that the “Metsovo mesothelioma epidemic” would decline by 2020–2030 [8]. Figure 1– Percentage of Metsovo (Greece) households using luto from 1940–1990 (•) and the decline in Metsovo malignant mesothelioma (MM) cases between 1980 and 2009 in 5-yr (white bars) and 10-yr intervals (grey bars). In the …