Clinically-relevant animal cervical spinal cord injury (SCI) models are essential for developing and testing potential therapies; however, producing reliable cervical SCI is difficult due to lack of satisfactory methods of vertebral stabilization. The conventional method to stabilize the spine is to suspend the rostral and caudal cervical spine via clamps attached to cervical spinous processes. However, this method of stabilization fails to prevent tissue yielding during the contusion as the cervical spinal processes are too short to be effectively secured by the clamps (Figure 1). Here we introduce a new method to completely stabilize the cervical vertebra at the same level of the impact injury. This method effectively minimizes movement of the spinal column at the site of impact, which greatly improves the production of consistent SCIs. We provide visual description of the equipment (Figure 2-4), methods, and a step-by-step protocol for the stabilization of the cervical 5 vertebra (C5) of adult rats, to perform laminectomy (Figure 5) and produce a contusive SCI thereafter. Although we only demonstrate a cervical hemi-contusion using the NYU/MASCIS impactor device, this vertebral stabilization technique can be applied to other regions of the spinal cord, or be adapted to other SCI devices. Improving spinal cord exposure and fixation through vertebral stabilization may be valuable for producing consistent and reliable injuries to the spinal cord. This vertebral stabilization method can also be used for stereotactic injections of cells and tracers, and for imaging using two-photon microscopy in various neurobiological studies.

This study was performed to select suitable indicator for scheduling the irrigation of jujube ( Ziziphus jujuba Mill. ) grown in the Loess Plateau. The relationships between plant-based indicators and soil matrix potential as well as meteorological factors of jujube under deficit irrigation compared with well irrigation were determined. The results showed that maximum daily trunk shrinkage increased and maximum daily trunk diameter, gas conductance and midday leaf water potential decreased in response to higher and lower soil matrix potential, respectively. However, the maximum daily trunk shrinkage signal intensity to noise ratio was highest in response to higher and lower soil matrix potential. Besides, the maximum daily trunk shrinkage correlated well with reference evapotranspiration and vapor pressure deficit (r 2 = 0.702 and 0.605 respectively). When the soil water potential was greater than -25kPa or less than –40 kPa, maximum daily trunk shrinkage values showed increasing trend, suggesting that Jujube might be subject to water stress. Based on this, the suitable soil water potential values of pear-jujube in anthesis and setting periods were identified between -40 kPa and - 25 kPa and the values can conduct precise irrigation of jujube in the Loess Plateau. Keywords: Water stress, water status indicators, soil water potential, Jujube ( Ziziphus jujuba Mill. ), anthesis, fruit setting periods African Journal of Biotechnology Vol. 9(35), pp. 5694-5703, 30 August, 2010

ABSTRACT Periodontitis is a chronic human inflammatory disease initiated and sustained by dental plaque microorganisms. A major contributing pathogen is Porphyromonas gingivalis , a gram-negative bacterium recognized by Toll-like receptor 2 (TLR2) and TLR4, which are expressed by human gingival epithelial cells (HGECs). However, it is still unclear how these cells respond to P. gingivalis and initiate inflammatory and immune responses. We have reported previously that HGECs produce a wide range of proinflammatory cytokines, including interleukin-6 (IL-6), IL-8, granulocyte-macrophage colony-stimulating factor, tumor necrosis factor alpha (TNF-α), and IL-1β. In this study, we show that IL-1β has a special role in the modulation of other inflammatory cytokines in HGECs challenged with P. gingivalis . Our results show that the increased production of IL-1β correlates with the cell surface expression of TLR4, and more specifically, TLR4-normal HGECs produce fourfold more IL-1β than do TLR4-deficient HGECs after challenge. Moreover, blocking the IL-1β receptor greatly reduces the production of “secondary” proinflammatory cytokines such as IL-8 or IL-6. Our data indicate that the induction of IL-1β plays an important role in mediating the release of other proinflammatory cytokines from primary human epithelial cells following challenge with P. gingivalis , and this process may be an inflammatory enhancement mechanism adopted by epithelial cells.

Spinal cord injury causes progressive secondary tissue degeneration, leaving many injured people with neurological disabilities. There are no satisfactory neuroprotective treatments. Protein tyrosine phosphatases inactivate neurotrophic factor receptors and downstream intracellular signaling molecules. Thus, we tested whether the peroxovanadium compound potassium bisperoxo(1,10-phenanthroline)oxovanadate (V) [bpV(phen)], a stable, potent and selective protein tyrosine phosphatase inhibitor, would be neuroprotective after a thoracic spinal cord contusion in adult rats. Intrathecal bpV(phen) infusions through a lumbar puncture rescued dorsal column sensory axons innervating the nucleus gracilis and white matter at the injury epicenter. At the most effective dose, essentially all of these axons and most of the white matter at the epicenter were spared (vs ∼60% with control infusions). bpV(phen) treatments started 4 h after contusion were fully effective. This treatment greatly improved and normalized sensorimotor function in a grid-walking test and provided complete axonal protection over 6 weeks. The treatment rescued sensory-evoked potentials that disappeared after dorsal column transection. bpV(phen) affected early degenerative mechanisms, because the main effects were seen at 7 d and lasted beyond the treatment period. The neuroprotection appeared to be mediated by rescue of blood vessels. bpV(phen) reduced apoptosis of cultured endothelial cells. These results show that a small molecule, used in a clinically relevant manner, reduces loss of long-projecting axons, myelin, blood vessels, and function in a model relevant to the most common type of spinal cord injury in humans. They reveal a novel mechanism of spinal cord degeneration involving protein tyrosine phosphatases that can be targeted with therapeutic drugs.

This study examined whether duraplasty after acute cervical laceration spinal cord injury (SCI) in a rat model could (1) improve cerebrospinal fluid (CSF) circulation adjacent to the injury; (2) minimize connective tissue scarring; and (3) reduce post-traumatic inflammation and cystic cavitation. Following a transverse dural/arachnoid incision and C5-6 dorsal spinal hemisection, a 5-mm(2) cadaveric dura mater allograft was placed over the lesion and fixed with fibrin glue (n = 12). Control animals received an identical dural/arachnoid incision and cervical dorsal hemisection without dural repair (n = 12). At 1, 5, and 10 weeks post-injury, plain film myelograms were obtained to characterize CSF circulation, and stereological methods were used to compare the extent of tissue sparing between the two groups. Immunohistochemical studies were performed to assess the degree of inflammation (ED-1), connective tissue scarring (laminin and type IV collagen), and reactive astrogliosis (GFAP). Our results indicate that dural allograft can improve CSF flow adjacent to the site of injury, which may be due to reduced meningeal fibrosis/scarring at the lesion site. Stereological analysis demonstrated that duraplasty resulted in a significant reduction in lesion volume at each time-point (P < 0.01) associated with a nearly complete attenuation of post-traumatic cystic cavitation (p < 0.001). Immunofluorescence studies demonstrated that duraplasty reduced the infiltration of ED-1-positive macrophages/microglia into and surrounding the lesion site, which may be responsible for the marked reduction in secondary injury following duraplasty. We conclude that duraplasty following acute spinal cord laceration may (1) improve CSF flow by limiting meningeal fibrosis; (2) reduce connective tissue scar formation; and (3) attenuate macrophage accumulation and progressive secondary injury.

Several recent studies in animals as well as humans support the notion that bone marrow (BM)-derived cells participate in brain regeneration. However, the identity of the specific cell type responsible for regeneration remains unknown. Recent work from our laboratory revealed that BM contains a highly mobile population of CXCR4+ cells that express mRNA for various markers of early tissue-committed stem cells (TCSC) and which are distinct from hematopoietic stem cells (HSC) (Leukemia 2004: 18;29–40). In this study we investigated whether BM also contains a mobile pool of TCSC destined to differentiate into neural cells. The TCSC were isolated from bone marrow by employing chemotactic gradient to SDF-1 or by FACS sorting and subsequently evaluated for a presence of early neural markers by i) real time RT-PCR analysis (nestin, GFAP), ii) immunohistochemical staining (nestin, beta-III tubulin), and iii) by employing functional in vitro assays to study ability of these purified cells to form neurospheres. Our data demonstrate that TCSC for neural cells (i) are present in significant amounts in BM harvested from young (1–2 month-old) while being barely detectable in older (1-year-old) mice; ii) reside in populations of murine BM-derived non-adherent non-hematopoietic Sca-1+ CD45− cells and in population of human CXCR4+ CD34+ AC133+ CD45− BMMNC, iii) are mobilized from BM into peripheral blood (PB) during pharmacological mobilization or 24 hours after Bengal-rose induced stroke in mice; iv) SDF-1 is highly upregulated in damaged brain tissue, and v) TCSC are chemoattracted for potential brain regeneration in SDF-1-CXCR4, dependent manner. Thus, we conclude that bone marrow is a potential source of TCSC for brain repair and since purified CD45+ HSC neither express neuronal markers nor differentiate in vitro into neurospheres, we provide for a first time evidence that neural TCSC residing in bone marrow but not “plastic” HSC account for neural differentiation of BM-derived cells. Furthermore, our observation that the number of marrow derived mobile/circulating neural TCSC is the highest in BM of young animals and decreases with age provides a novel insight into aging and may explain why the brain regeneration process becomes less effective in older individuals. Finally, these observations provide rationale for further studies aimed at optimizing therapeutic brain regeneration by BM-derived neural TCSC.

目的观察在培养的神经干细胞内是否有发育调控分子--音猬因子(sonic hedgehog)功能受体--斑片(patched)表达. 方法神经干细胞克隆在体外培养传代后,用patched的特异性引物对培养的神经干细胞进行RT-PCR分析,PCR产物经克隆测序后,用地高辛标记克隆的探针,对神经干细胞进行原位杂交分析. 结果神经干细胞克隆内大量的细胞均可表达sonic hedgehog的功能受体patched,patched阳性细胞间未见明显差别,克隆边缘与中央的patched分布也未见明显差别. 结论 sonic hedgehog信号传导路可能在神经干细胞的增殖与分化过程中起重要作用.

Topiramate, a structurally novel anticonvulsant, and phenytoin were evaluated in a rat model of ischemia-induced epilepsy. In this model a transient global cerebral ischemia is induced by cardiac compression. By precisely controlling the experimental conditions the procedure causes reproducible neurological deficits that include audiogenic epileptic seizures. The seizures can be broadly separated into three types reflecting the degree of severity: wild running, clonic seizures, and tonic extension seizures of the forelimbs and hindlimbs. Topiramate and phenytoin blocked all three types of seizures. Calculated ED50 values for topiramate 1 hr after oral administration were 8.2, 13.0 and 36.1 mg/kg for blockade of tonic extension seizures, clonic seizures and wild running, respectively. Corresponding ED50 values for phenytoin were 5.0, 10.8 and 20.7 mg/kg. These results support the concept that the anticonvulsant activity of these drugs is due primarily to an ability to block the spread of seizures.