Does spinal block through tattooed skin cause histological changes in nervous tissue and meninges?: an experimental model in rabbits

Although there is no documented evidence that tattoo pigments can cause neurological complications, the implications of performing neuraxial anesthesia through tattooed skin are unknown. In this study, we aimed to assess whether spinal puncture performed through tattooed skin of rabbits determines changes over the spinal cord and meninges. In addition, we sought to evaluate the presence of ink fragments entrapped in spinal needles. Thirty-six young male adult rabbits, each weighing between 3400 and 3900 g and having a spine length between 38.5 and 39 cm, were divided by lot into 3 groups as follows: GI, spinal puncture through tattooed skin; GII, spinal puncture through tattooed skin and saline injection; and GIII, spinal puncture through skin free of tattoo and saline injection. After intravenous anesthesia with ketamine and xylazine, the subarachnoid space was punctured at S1-S2 under ultrasound guidance with a 22-gauge 2½ Quincke needle. Animals in GII and GIII received 5 μL/cm of spinal length (0.2 mL) of saline intrathecally. In GI, the needle tip was placed into the yellow ligament, and no solution was injected into the intrathecal space; after tattooed skin puncture, 1 mL of saline was injected through the needle over a histological slide to prepare a smear that was dyed by the Giemsa method to enable tissue identification if present. All animals remained in captivity for 21 days under medical observation and were killed by decapitation. The lumbosacral spinal cord portion was removed for histological analysis using hematoxylin-eosin stain. None of the animals had impaired motor function or decreased nociception during the period of clinical observation. None of the animals from the control group (GIII) showed signs of injuries to meninges. In GII, however, 4 animals presented with signs of meningeal injury. The main histological changes observed were focal areas of perivascular lymphoplasmacyte infiltration in the pia mater and arachnoid. There was no signal of injury in neural tissue in any animal of both groups. Tissue coring containing ink pigments was noted in all GI smears from the spinal needles used to puncture the tattooed skin. On the basis of the present results, intrathecal injection of saline through a needle inserted through tattooed skin is capable of producing histological changes over the meninges of rabbits. Ink fragments were entrapped inside the spinal needles, despite the presence of a stylet.

Proteomic analysis of the rare Uracoan rattlesnake Crotalus vegrandis venom: evidence of a broad arsenal of toxins

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Crystal structure of Staphylococcus aureus exfoliative toxin D-like protein: structural basis for the high specificity of exfoliative toxins

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Thrombocytopenia and platelet hypoaggregation induced by Bothrops asper snake venom Toxins involved and their contribution to metalloproteinase-induced pulmonary hemorrhage

Thrombocytopenia and platelet dysfunction occur in patients bitten by Bothrops sp snakes in Latin America. An experimental model was developed in mice to study the effects of B. asper venom in platelet numbers and function. Intravenous administration of this venom induces rapid and prominent thrombocytopenia and ex vivo platelet hypoaggregation. The drop in platelet numbers was primarily due to aspercetin, a protein of the C-type lectin family which induces von Willebrand factor-mediated platelet aggregation/agglutination. In addition, the effect of class P-III hemorrhagic metalloproteinases on the microvessel wall also contributes to thrombocytopenia since jararhagin, a P-III metalloproteinase, reduced platelet counts. Hypoaggregation was associated with the action of procoagulant and defibrin(ogen)ating proteinases jararacussin-1 (a thrombin-like serine proteinase) and basparin A (a prothrombin activating metalloproteinase). At the doses which induced hypoaggregation, these enzymes caused defibrin(ogen)ation, increments in fibrin(ogen) degradation products and D-dimer and prolongation of the bleeding time. Incubation of B. asper venom with batimastat and α 2-macroglobulin abrogated the hypoaggregating activity, confirming the role of venom proteinases in this effect. Neither aspercetin nor the defibrin(ogen)ating and hypoaggregating components induced hemorrhage upon intravenous injection. However, aspercetin, but not the thrombin-like or the prothrombin-activating proteinases, potentiated the hemorrhagic activity of two hemorrhagic metalloproteinases in the lungs. © 2005 Schattauer GmbH, Stuttgart.

Development and in vitro skin delivery of dexamethasone acetate-loaded surfactant-based systems

Topical corticosteroids, e.g., dexamethasone acetate (DMA), are extensively used to treat cutaneous inflammatory disorders even though their use is correlated with potential local and systemic side effects. The objective of this study was to develop and test the topical delivery of DMA-loaded surfactant based systems in vitro; these studies could guarantee a suitable delivery and therapeutic efficacy, as well as minimize DMA's side effects. A phase diagram was constructed using polyoxypropylene (5) polyoxyethylene (20) cetyl alcohol as the surfactant (S), isopropyl myristate as the oil phase (O) and water (W). The systems were characterized using polarization light microscopy (PLM), as well as rheological and small angle X-ray scattering (SAXS) measurements. Depending on the concentration of the constituents, it was possible to obtain microemulsions (MEs) and liquid crystalline mesophases (lamellar and hexagonal). These types of arrangement were verified using PLM measurements. The SAXS results revealed that increasing the W/S ratio led to ME, as well as lamellar (LAM) and hexagonal (HEX) arrangements. The MEs displayed typical Newtonian behavior while the LAM and HEX phases exhibited pseudoplasticity and plasticity, respectively. The MEs displayed excellent drug solubilization that was approximately 10-fold higher than was observed with the individual components. The in vitro cutaneous permeation studies using pig ear skin and analysis of the mechanical parameters (hardness, compressibility, cohesiveness and adhesiveness) were carried out with a HEX phase and O/W emulsion. The HEX phase achieved better drug permeation and retention in the skin while its mechanical properties were suitable for skin administration. PPG-5-CETETH-20-based systems may be a promising platform delivering DMA and other topical corticosteroids through the skin.

Surfactant-based transdermal system for fluconazole skin delivery

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Tuberculin Skin Testing in White-Tailed Deer (Odocoileus virginianus)

The comparative cervical skin test for antemortem diagnosis of tuberculosis was done 169 times on 116 different white-tailed deer of known Mycobacterium bovis infection status. The sensitivity and specificity were 97 and 81%, respectively. The magnitude of change in skin thickness at test sites was not significantly influenced by dosage of inoculum, dissemination of the disease process, or repeated skin testing. However, the magnitude of change in skin thickness was significantly greater in deer infected for less than 109 days than in deer infected for more than 109 days. As used in the present study, the comparative cervical skin test is a sensitive method of antemortem diagnosis of M. bovis infection in white-tailed deer.

Skin lesions on blue whales off southern Chile: Possible conservation implications?

We report on three types of skin lesions in a population of blue whales, Balaenoptera musculus, off the northwestern coast of Isla Grande de Chiloe, Chile. These lesions were: (1) cookie-cutter shark, Isistius brasilensis, bites, (2) vesicular or blister lesions, and (3) a tattoo-like skin disease. The presence of these lesions was determined by the examining photos collected in 2006 and 2007 for a blue whale photo-identification project. We examined 289 photographs of 68 individuals for lesions. The cookie-cutter shark lesions are common on these blue whales and similar to those reported from other species of cetaceans. Skin peeling or shedding was observed on some whales and is believed to be a normal condition. Based on the photographs examined to date the vesicular lesions are more common than the tattoo-like lesions. The tattoo-like skin lesions was observed just on a single whale in 2007. The blister lesions were common on whales in both 2006 and 2007. The presence of blister lesions in both years may indicate that this “disease” will be present in the population for a long time. It is unknown if these lesions contribute to mortality of blue whales frequenting Chilean waters, but the tattoo-like skin lesions if shown to be a pox virus could cause neonatal and calf mortality. Additional investigations are needed that, as a minimum, must include the histological and genetic examination of the two types of disease from live or dead whales, especially the tattoo-like skin lesions. Until this work is undertaken, it will be impossible to determine if these lesions pose a conservation risk to the blue whales off Chile.

Nitric oxide is responsible for oxidative skin injury and modulation of cell proliferation after 24 hours of UVB exposures

Nitric oxide (NO) is produced by various mammalian cells and plays a variety of regulatory roles in normal physiology and in pathological processes. This article provides evidence regarding the participation of NO in UVB-induced skin lesions and in the modulation of skin cell proliferation following UVB skin irradiation. Hairless mice were subjected to UVB irradiation for 3 hours and the skin evaluated immediately, 6 and 24 hours postirradiation. The skin lipid peroxidation, and NO levels evaluated by chemiluminescence and inducible nitric oxide synthase (iNOS) and nitrotyrosine immunolabelling increased significantly 24 hours after irradiation and decreased under the treatment with aminoguanidine (AG). On the other hand, cell proliferation markers, PCNA and VEGF showed a strong labelling index when AG was used. The data indicate that NO mediates, at least in part, the lipid peroxidation and protein nitration and also promotes the down regulation of factors involved in cell proliferation. This work shows that the NO plays an important role in the oxidative stress damage and on modulation of cell proliferation pathways in UVB irradiated skin.

Transforming growth factor beta and apoptosis in leprosy skin lesions: possible relationship with the control of the tissue immune response in the Mycobacterium leprae infection

The course of leprosy depends of the host immune response which ranges from the lepromatous pole (LL) to the tuberculoid pole (TT). A comparative study was conducted in 60 patients with the LL and TT The results showed a mean expression of TGF-beta of 339 +/- 99.4 cells/field for TT and of 519.2 +/- 68.2 cells/field for LL. Frequency of apoptosis was 6.3 +/- 1.8 in TT and 14.0 +/- 6.1 in LL. A correlation (p = 0.0251) between TGF-beta and caspase-3 in the LL was found. This finding indicates a role of TGF-beta and apoptosis in the immune response in leprosy. (C) 2012 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Gamma Radiation Effects on Peanut Skin Antioxidants

Peanut skin, which is removed in the peanut blanching process, is rich in bioactive compounds with antioxidant properties. The aims of this study were to measure bioactive compounds in peanut skins and evaluate the effect of gamma radiation on their antioxidant activity. Peanut skin samples were treated with 0.0, 5.0, 7.5, or 10.0 kGy gamma rays. Total phenolics, condensed tannins, total flavonoids, and antioxidant activity were evaluated. Extracts obtained from the peanut skins were added to refined-bleached-deodorized (RBD) soybean oil. The oxidative stability of the oil samples was determined using the Oil Stability Index method and compared to a control and synthetic antioxidants (100 mg/kg BHT and 200 mg/kg TBHQ). Gamma radiation changed total phenolic content, total condensed tannins, total flavonoid content, and the antioxidant activity. All extracts, gamma irradiated or not, presented increasing induction period (h), measured by the Oil Stability Index method, when compared with the control. Antioxidant activity of the peanut skins was higher than BHT. The present study confirmed that gamma radiation did not affect the peanut skin extracts' antioxidative properties when added to soybean oil.

Charcot foot: Skin temperature as a good clinical parameter for predicting disease outcome

Twenty-eight diabetics presenting with acute Charcot foot were immobilized and the temperature difference between limbs measured at each month. All patients had monthly follow-up visits for a year and the relapse rate was zero. We found that skin temperature is a good parameter to ensure safe immobilization withdrawal. (C) 2011 Elsevier Ireland Ltd. All rights reserved.

The imbalance between Treg and Th17 cells caused by FTY720 treatment in skin allograft rejection

OBJECTIVES: FTY720 modulates CD4(+)T cells by the augmentation of regulatory T cell activity, secretion of suppressive cytokines and suppression of IL-17 secretion by Th17 cells. To further understand the process of graft rejection/acceptance, we evaluated skin allograft survival and associated events after FTY720 treatment. METHODS: F1 mice (C57BL/6xBALB/c) and C57BL/6 mice were used as donors for and recipients of skin transplantation, respectively. The recipients were transplanted and either not treated or treated with FTY720 by gavage for 21 days to evaluate the allograft survival. In another set of experiments, the immunological evaluation was performed five days post-transplantation. The spleens, axillary lymph nodes and skin allografts of the recipient mice were harvested for phenotyping (flow cytometry), gene expression (real-time PCR) and cytokine (Bio-Plex) analysis. RESULTS: The FTY720 treatment significantly increased skin allograft survival, reduced the number of cells in the lymph nodes and decreased the percentage of Tregs at this site in the C57BL/6 recipients. Moreover, the treatment reduced the number of graft-infiltrating cells and the percentage of CD4(+) graft-infiltrating cells. The cytokine analysis (splenocytes) showed decreased levels of IL-10, IL-6 and IL-17 in the FTY720-treated mice. We also observed a decrease in the IL-10, IL-6 and IL-23 mRNA levels, as well as an increase in the IL-27 mRNA levels, in the splenocytes of the treated group. The FTY720-treated mice exhibited increased mRNA levels of IL-10, IL-27 and IL-23 in the skin graft. CONCLUSIONS: Our results demonstrated prolonged but not indefinite skin allograft survival by FTY720 treatment. This finding indicates that the drug did not prevent the imbalance between Tr1 and Th17 cells in the graft that led to rejection.

Liquid Crystal Nanodispersions Enable the Cutaneous Delivery of Photosensitizer for Topical PDT: Fluorescence Microscopy Study of Skin Penetration

Topical photodynamic therapy (PDT) has been applied to almost all types of nonmelanoma skin cancer and numerous superficial benign skin disorders. Strategies to improve the accumulation of photosensitizer in the skin have been studied in recent years. Although the hydrophilic phthalocyanine zinc compound, zinc phthalocyanine tetrasulfonate (ZnPcSO4) has shown high photodynamic efficiency and reduced phototoxic side effects in the treatment of brain tumors and eye conditions, its use in topical skin treatment is currently limited by its poor skin penetration. In this study, nanodispersions of monoolein (MO)-based liquid crystalline phases were studied for their ability to increase ZnPcSO4 uptake by the skin. Lamellar, hexagonal and cubic crystalline phases were prepared and identified by polarizing light microscopy, and the nanodispersions were analyzed by dynamic light scattering. In vitro skin penetration studies were performed using a Franz's cell apparatus, and the skin uptake was evaluated in vivo in hairless mice. Aqueous dispersions of cubic and hexagonal phases showed particles of nanometer size, approximately 224 +/- 10 nm and 188 +/- 10 nm, respectively. In vitro skin retention experiments revealed higher fluorescence from the ZnPcSO4 in deeper skin layers when this photosensitizer was loaded in the hexagonal nanodispersion system when compared to both the cubic phase nanoparticles and the bulk crystalline phases (lamellar, cubic and hexagonal). The hexagonal nanodispersion showed a similar penetration behavior in animal tests. These results are important findings, suggesting the development of MO liquid crystal nanodispersions as potential delivery systems to enhance the efficacy of topical PDT.