NADPH-d and Fos reactivity in the rat spinal cord following experimental spinal cord injury and embryonic neural stem cell transplantation

AimsThe aim of this study is to determine the role of nitric oxide (NO) in neuropathic pain and the effect of embryonic neural stem cell (ENSC) transplantation on NO content in rat spinal cord neurons following spinal cord injury (SCI).Main methodsNinety adult male Sprague–Dawley rats were divided into 3 groups (n = 30, each): control (laminectomy), SCI (hemisection at T12–T13 segments) and SCI + ENSC. Each group was further divided into sub-groups (n = 5 each) based on the treatment substance (L-NAME, 75 mg/kg/i.p.; l-arginine, 225 mg/kg/i.p.; physiological saline, SF) and duration (2 h for acute and 28 days for chronic groups). Pain was assessed by tail flick and Randall–Selitto tests. Fos immunohistochemistry and NADPH-d histochemistry were performed in segments 2 cm rostral and caudal to SCI.Key findingsTail-flick latency time increased in both acute and chronic L-NAME groups and increased in acute and decreased in chronic l-arginine groups. The number of Fos (+) neurons decreased in acute and chronic L-NAME and decreased in acute l-arginine groups. Following ENSC, Fos (+) neurons did not change in acute L-NAME but decreased in the chronic L-NAME groups, and decreased in both acute and chronic l-arginine groups. NADPH-d (+) neurons decreased in acute L-NAME and increased in l-arginine groups with and without ENSC transplantation.SignificanceThis study confirms the role of NO in neuropathic pain and shows an improvement following ENSC transplantation in the acute phase, observed as a decrease in Fos(+) and NADPH-d (+) neurons in spinal cord segments rostral and caudal to injury.     

Acid-bile, antibiotic resistance and inhibitory properties of propionibacteria isolated from Turkish traditional home-made cheeses

In this study, a total of 29 Propionibacterium spp. were isolated from traditional home-made Turkish cheese samples. As a result of the identification, isolates were identified as Propionibacterium freudenreichii subsp. freudenreichii (15 strains), Propionibacterium jensenii (12), and Propionibacterium thoenii (2). All isolates and 5 reference strains were examined for their abilities to survive at pH 2.0, 3.0, 4.0, 5.0 and in the presence of 0.06, 0.15 and 0.30% bile salts, their influence on the growth of food-borne and spoilage bacteria, as well as their sensitivity against 11 selected antibiotics. Only seven propionibacteria strains survived in both the acidic and bile salt environments. Propionibacterium spp. strains strongly inhibited growth of the Escherichia coli ATCC 11229 and Shigella sonnei Mu:57 strains (91%). All propionibacteria strains were sensitive to a majority of the antibiotics used in the investigations. Overall, dairy propionibacteria showed high antibacterial activity, resistance to pH 4.0, 5.0, high resistance to bile salts and will provide an alternative source to Lactobacillus and Bifidobacterium as probiotic culture.     

A new electrochemical method for the production of stable ascorbate free radicals

A new method for the production of ascorbate free radicals is established. The radical is produced from ascorbate in deionized water by applying constant potential electrolysis under a nitrogen atmosphere. Prior to electrolysis, a cyclic voltammogram (CV) of the ascorbic acid was obtained. Electrolysis potentials were selected as the oxidation peak potential of the ascorbic acid obtained by CV. The detection of the radical was done by electron spin resonance (esr) and uv spectroscopies.     

Incorporating spatial criteria in optimum reserve network selection

Considering the spatial location of sites that are to be selected for inclusion in a protected reserve network may be necessary to facilitate dispersal and long-term persistence of species in the selected sites. This paper presents an integer programming (IP) approach to the reserve network selection problem where spatial considerations based on intersite distances are taken into account when selecting reserve sites. The objective is to reduce the fragmentation of preserved sites and design a compact reserve network. Two IP formulations are developed which minimize the sum of pairwise distances and the maximum intersite distance between all sites in the reserve network, respectively, while representing all species under consideration. This approach is applied to a pond invertebrate dataset consisting of 131 sites containing 256 species in Oxfordshire, UK. The results show that significant reductions in reserve fragmentation can be achieved, compared with spatially unrestricted optimum reserve selection, at the expense of a small loss in reserve efficiency.     

Changes in end-expiratory lung volume during sleep in patients with occlusive apnea

Eight patients with occlusive sleep apnea were monitored during non-rapid-eye-movement (NREM) sleep to study the factors that contribute to negative inspiratory pressure generation and thus upper airway occlusion. End-expiratory lung volume assessed by respiratory inductive plethysmography [sum of end-expiratory levels (SUM EEL)] increased early and decreased late during the ventilatory phases (P less than 0.0001, one-way analysis of variance). Inspiratory change in esophageal pressure (Pes) and peak inspiratory diaphragmatic and genioglossal electromyograms (EMGdi and EMGge) decreased while the inspiratory pressure generated for a given diaphragmatic activity (Pes/EMGdi) increased during the preapneic phase (P less than 0.0001, for all). Multiple regression analysis with Pes/EMGdi as the dependent variable (R2 = 0.90) indicated that both the changes in SUM EEL and EMGge significantly contributed to the model (P less than 0.008 and 0.004, respectively). These results indicate that end-expiratory lung volume fluctuates during NREM sleep in patients with occlusive apnea and suggest that these changes along with the changes in upper airway muscle activity contribute to the generation of negative inspiratory pressure, leading to the passive collapse of the upper airways.