Gsx1 promotes locomotor functional recovery after spinal cord injury.

Promoting residential cells, particularly endogenous neural stem and progenitor cells (NSPCs), for tissue regeneration represents a potential strategy for the treatment of spinal cord injury (SCI). However, adult NSPCs differentiate mainly into glial cells and contribute to glial scar formation at the site of injury. Gsx1 is known to regulate the generation of excitatory and inhibitory interneurons during embryonic development of the spinal cord. In this study, we show that lentivirus-mediated expression of Gsx1 increases the number of NSPCs in a mouse model of lateral hemisection SCI during the acute stage. Subsequently, Gsx1 expression increases the generation of glutamatergic and cholinergic interneurons and decreases the generation of GABAergic interneurons in the chronic stage of SCI. Importantly, Gsx1 reduces reactive astrogliosis and glial scar formation, promotes serotonin (5-HT) neuronal activity, and improves the locomotor function of the injured mice. Moreover, RNA sequencing (RNA-seq) analysis reveals that Gsx1-induced transcriptome regulation correlates with NSPC signaling, NSPC activation, neuronal differentiation, and inhibition of astrogliosis and scar formation. Collectively, our study provides molecular insights for Gsx1-mediated functional recovery and identifies the potential of Gsx1 gene therapy for injuries in the spinal cord and possibly other parts of the central nervous system.

Risk Factors Predicting Positive Margins at Primary Wide Local Excision of Cutaneous Melanoma.

BACKGROUND: A small percentage of patients will have positive histological margins after primary wide local excision (WLE) of cutaneous melanoma (CM). Risk factors that predict marginal involvement at WLE remain unclear. OBJECTIVE: To identify risk factors associated with positive margins after WLE of CM. MATERIALS AND METHODS: A retrospective review of patients treated at a single institution for CM with sentinel lymph node biopsy from 1997 to 2011 was conducted. RESULTS: Positive margins occurred in 6% of patients. Patients with positive margins were older (72.4 vs 60.7, p < .001), had thicker tumors (3.6 vs 1.9 mm, p < .001), and often involved the head and neck region (p < .001). Patients with positive margins at WLE had positive margins on initial biopsy (p = .012) and a higher rate of a melanoma in situ component on initial biopsy (24% vs 11%, p = .02). The 5-year local recurrence rate was significantly different between those with positive and negative margins at WLE (16.0% vs 6.9%; p = .047). CONCLUSION: Positive margins after WLE are uncommon. When a patient has multiple risk factors for positive margins at WLE, histologically clear margins should be obtained through mapped serial excision or Mohs micrographic surgery.

A Simple Metric for Determining Resolution in Optical, Ion, and Electron Microscope Images.

A resolution metric intended for resolution analysis of arbitrary spatially calibrated images is presented. By fitting a simple sigmoidal function to pixel intensities across slices of an image taken perpendicular to light-dark edges, the mean distance over which the light-dark transition occurs can be determined. A fixed multiple of this characteristic distance is then reported as the image resolution. The prefactor is determined by analysis of scanning transmission electron microscope high-angle annular dark field images of Si. This metric has been applied to optical, scanning electron microscope, and helium ion microscope images. This method provides quantitative feedback about image resolution, independent of the tool on which the data were collected. In addition, our analysis provides a nonarbitrary and self-consistent framework that any end user can utilize to evaluate the resolution of multiple microscopes from any vendor using the same metric.

Stimulation of murine intestinal secretion by daily genistein injections: gender-dependent differences.

BACKGROUND/AIMS: The effect of daily injections with genistein (naturally occurring phytoestrogen) on intestinal chloride (Cl(-)) secretion was measured with Ussing chamber short circuit current (I(sc), µA/cm(2)), in C57BL/6J male and female mice, using 600 mg/kg genistein/day (600G), 300 mg/kg genistein/day (300G), 150 mg/kg genistein/day (150G) or genistein-free vehicle control (0G) for 1- or 2-weeks. METHODS AND RESULTS: Injecting with 600G elicited significant increases in basal I(sc) in females after 1-week (ñ70 µA/cm(2), n=15, p < 0.05) and in males after 2-weeks (ñ80 µA/cm(2), n=5, p < 0.05) compared to their 0G counterparts. Chloride-free ringer significantly reduced basal I(sc) by 65% in 600G males and 72% in 600G females, suggesting that Cl(-) was the major anion comprising the genistein-stimulated secretion. The forskolin-stimulated (10 µM) I(sc) was significantly inhibited by the CFTR chloride channel inhibitors, glibenclamide (500 µM) and CFTR(inh)-172 (100 µM) in 600G males and females, suggesting some contribution by genistein-dependent CFTR-mediated Cl(-) secretion. We found no associated changes in intestinal morphology, nor change in total CFTR protein with 600G. There was a 5% increase in apical/subapical ratio in 600G males compared to controls (no change in females). CONCLUSION: These data suggest that male and female mice both exhibit increased Cl- secretion with 600G, however, the mechanisms mediating this are gender-dependent.

Calcaneal osteochondroma.

Osteochondromas are essentially the most common primary bone tumors. These benign cartilage producing neoplasms are generally asymptomatic and have a relatively small potential for adverse effects. HME, the familial form of this tumor, is associated with a greater incidence of complications, the most significant of which is sarcomatous degeneration to secondary chondrosarcomas. Various imaging techniques can be used to characterize these lesions, but in the absence of symptoms or signs of complications, plain-film radiography is usually sufficient for diagnosis as this tumor has a characteristic radiographic appearance. Once this benign tumor is identified and more serious forms of tumor are ruled out, treatment is generally not needed. If a malignancy is suspected, however, complete surgical excision is the preferred treatment as this usually ensures long term survival.

Long range molecular wire behaviour in a metal complex of DNA.

M-DNA is a complex of metal ions such as Zn(2+) with duplex DNA. Previous results showed that the fluorescence of a donor fluorophore was quenched when an acceptor fluorophore was placed at the opposite end of a short M-DNA duplex. In order to investigate further the molecular wire behaviour of M-DNA, 30-mer duplexes were constructed with fluorescein as donor and rhodamine, pyrene and the cyanine dyes, Cy5 and Cy5.5 as acceptors. Good quenching was observed in all cases even though the efficiency of resonance energy transfer was calculated to be < 5%. The distance dependence of quenching was investigated by preparing doubly-labelled duplexes ranging in length from 20 to 1,000 base pairs. Upon formation of M-DNA significant quenching of the fluorescence of the donor fluorophore was observed in duplexes up to 500 base pairs in length. The amount of quenching decreased with increasing length of the duplexes with a shallow distance dependence. The results are consistent with an electron transfer mechanism in which the electron hops between metal centers. This process can occur efficiently over long distances.