Injury of peripheral nerve is associated with the development of post-traumatic neuroma at the end of the proximal stump, often being the origin of neuropathic pain. This type of pain is therapy-resistant and therefore extremely nagging for patients. We examined the influence of the microcrystallic chitosan gel applied to the proximal stump of totally transected sciatic nerve on the neuroma formation and neuropathic pain development in rats. In 14 rats, right sciatic nerve was transected and the distal stump was removed to avoid spontaneous rejoining. In the chitosan (experimental) group (n = 7), the proximal stump was covered with a thin layer of the microcrystallic chitosan gel. In control animals (n = 7), the cut nerve was left unsecured. Autotomy, an animal model of neuropathic pain, was monitored daily for 20 weeks following surgery. Then, the animals were perfused transcardially and the proximal stumps of sciatic nerves were dissected and subjected to histologic evaluation. The presence, size, and characteristics of neuromas as well as extraneural fibrosis were examined. In chitosan group, the incidence and the size of the neuroma were markedly reduced, as compared with the control group; however, there was no difference in autotomy behavior between groups. In addition, extraneural fibrosis was significantly reduced in chitosan group when compared to the control group. The results demonstrate beneficial influence of microcrystallic chitosan applied to the site of nerve transection on the development of post-traumatic neuroma and reduction of extraneural fibrosis, however without reduction of neuropathic pain.
Loss of pancreatic β–cell is a critical factor in the pathogenesis of type 1 diabetes and it also occurs in type 2. TXNIP (thioredoxin – interacting protein), also known as vitamin D3-upregulated protein 1, or thioredoxin-binding-protein-2, regulates this process and modulates cellular redox balance. TXNIP is localized primarily in the nucleus, but under oxidative stress it moves to mitochondria, where it interacts with mitochondrial thioredoxin 2. Overexpression of TXNIP induced by hyperglycaemia is typical for diabetes and insulin resistance and leads to apoptosis of pancreatic β– cell, cardiomyopathy, metabolic disorders and multiple harmful effects. It activates NLRP3 inflamasomme and IL–1β, a cytokine involved in type 2 diabetes and insulin resistance. TXNIP influences peroxisome proliferator-activated receptor alpha transcriptional activity, expression of glucose transporter–1, nitric oxide production in endothelium and insulin production in β–cells. TXNIP overexpression leads to diabetic retinopathy, nephropathy, atherosclerosis, it occurs in cancers and autoimmune diseases, while its deficiency protects β cells. Reduction of TXNIP is an important target in diabetes treatment. In this mechanism insulin, metformin and inhibitors of dipeptydylopeptydase IV are involved. It has been observed that calcium channel blockers (CCB) used in hypertension also inhibit TXNIP expression in cardiomyocytes. L–type channels identification in pancreatic β-cells revealed that CCB inhibit TXNIP expression also in β–cells. For the first time, verapamil was distinguished as an agent that not only inhibits TXNIP expression in pancreatic β-cells, but also enhances β cell survival and function, and possibly prevents diabetes.
SummaryThe anterior cerebral artery is a common location of intracranial aneurysms. The standard coil embolization technique is limited by its inability to occlude wide-neck aneurysms. Stent deployment across the aneurysm neck supports the coil mass inside the aneurysmal sac, and furthermore, has an effect on local hemodynamic and biologic changes. In this article, various management strategies and techniques as well as angiographic outcomes and complications related to stent-assisted endovascular treatment of anterior communicating artery aneurysms are presented. This treatment method is safe and associated with low morbidity and mortality rates.
Background. Spinal cord injury (SCI) is an important cause of impairment of sensory and motor nerve function. It has been shown that free-radical species play an important role in the pathogenesis of acute tissue trauma after SCI. There are no proven pharmacological therapies that provide neuroprotection and stimulate axonal growth after trauma.
The aim of this study was to assess 17-β-estradiol (E 2 ) influence on sciatic nerve regeneration after injury followed by a repair with chitosan conduit in ovariectomized female rats.The study was performed in 2 groups (n = 16) of rats: OVChit -after excision of a fragment of the sciatic nerve, a chitosan conduit was implanted; OVChitE10 group -additionally to chitosan conduit, shape-memory terpolymer rods based on poly(L-lactide-co-glycolideco-trimethylene carbonate) releasing 17-β-estradiol for 20 weeks were implanted.The mean number of regenerating axons and mean fiber area were significantly greater in 17-β-estradiol-treated animals. In this group, the infiltrate of leukocytes was diminished. The presence of 17-β-estradiol receptors alpha and beta in motoneurons in the spinal cord were discovered. This may indicate the location where 17-β-estradiol affects the regeneration of the injured nerve.Estradiol released from the terpolymer rods for 20 weeks could enhance, to some extent, sciatic nerve regeneration after injury, and diminish the inflammatory reaction. In the future, 17-β-estradiol entrapped in terpolymer rods could be used in the repair of injured peripheral nerves, but there is a need for further studies.
Pineal parenchymal tumors (PPTs) in children and adolescents are uncommon and more data on their biological activity and behavior are still needed. The aim of our study was to estimate the expression and prognostic value of some proteins regulating apoptosis and cell cycle as well as being markers of cellular differentiation in PPTs. Tumor specimens obtained from 27 patients who underwent surgical treatment for PPTs were evaluated in immuno-histochemical analysis. The expression of Bcl-2, Bax, p53, NSE (neuron specific enolase), GFAP (glial fibrillary acidic protein), beta-III tubulin and nestin were studied. Co-localization of two chosen antibodies (e.g. Bcl-2/Bax, BCl-2/NSE, p53/NSE, etc.) was also made with a scanning confocal microscope. Histopathological examination revealed: 15 pineocytomas, 1 intermediately differentiated PPT and 11 pineoblastomas. For further analysis two groups were created: Group I: patients with pineocytoma or intermediately differentiated PPTs (16 cases) Group II: patients with pineoblastoma (11 cases). A statistically significant positive correlation between patients' survival time and tubulin and NSE expression was found. Bcl-2, p53 and nestin correlated negatively with survival time.
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