An Ultrasonically Powered Implantable Microprobe for Electrolytic Ablation.

Electrolytic ablation (EA) is a promising nonthermal tumor ablation technique that destroys malignant cells through induction of a locoregional pH change. EA is typically performed by inserting needle electrodes inside the tumor followed by application of direct current (DC), thus inducing electrolysis and creating localized pH changes around the electrodes. In this paper, we report an ultrasonically powered implantable EA microprobe that may increase the clinical relevance of EA by allowing wireless control over device operation (capability to remotely turn the device on and off) and providing flexibility in treatment options (easier to administer fractionated doses over a longer period). The wireless EA microprobe consists of a millimeter-sized piezoelectric ultrasonic receiver, a rectifier circuit, and a pair of platinum electrodes (overall size is 9 × 3 × 2 mm3). Once implanted through a minimally invasive procedure, the microprobe can stay within a solid tumor and be repeatedly used as needed. Ultrasonic power allows for efficient power delivery to mm-scale devices implanted deep within soft tissues of the body. The microprobe is capable of producing a direct current of 90 µA at a voltage of 5 V across the electrodes under low-intensity ultrasound (~200 mW/cm2). The DC power creates acidic (pH < 2) and alkaline (pH > 12.9) regions around the anode and the cathode, respectively. The pH change, measured using tissue-mimicking agarose gel, extends to 0.8 cm3 in volume within an hour at an expansion rate of 0.5 mm3/min. The microprobe-mediated EA ablative capability is demonstrated in vitro in cancer cells and ex vivo in mouse liver.

Triamcinolone acetonide protects the rat retina from STZ-induced acute inflammation and early vascular leakage.

Streptozotocin (STZ) has been commonly used to induce in vivo and in vitro hyperglycemic diabetes and its toxicity leads to inflammation and vascular injury. Triamcinolone acetonide (TA), as an anti-angiogenic/anti-inflammatory drug, is clinically used to improve the visual acuity in neovascular and edematous ocular diseases. The aim of this study was to investigate the effect of TA on early inflammation and vascular leakage in the retina of STZ-induced hyperglycemic rats. Hyperglycemia was induced in 8-week-old male Sprague-Dawley (SD) rats by a single intraperitoneal injection of STZ (65 mg/kg); only rats with blood glucose levels >13.9 mmol/l 1 day after STZ injection were included in STZ-hyperglycemic group. Sex- and age-matched SD rats injected with buffer were used as the control group. One day before STZ and buffer injection, 2 microl TA (4 mg/ml in saline) and 2 microl saline were intravitreal-injected into the right and the left eyes of rats, respectively. Retinal vascular leakage was measured using the Evans-blue method. Changes in pro-inflammatory target genes, such as tumor necrotic factor (TNF)-alpha, intracellular adhesion molecule (ICAM)-1, and vascular endothelial growth factor (VEGF) were assessed by immunoblottings, immunostaining, and ELISA analyses. Vascular hyperleakage and up-regulation of most pro-inflammatory genes peaked within a few days after STZ injection and had recovered. However, these changes were blocked by TA pretreatment. Our data suggest that TA controls STZ-induced early vascular leakage and temporary pro-inflammatory signals in the rat retina.

Triamcinolone suppresses retinal vascular pathology via a potent interruption of proinflammatory signal-regulated activation of VEGF during a relative hypoxia.

We examined the effect of triamcinolone acetonide (TA), a corticosteroid, on the relationship between vascular pathophysiology and vascular endothelial growth factor (VEGF) activation in the retina of a rat model of oxygen-induced retinopathy (OIR). OIR was induced by exposure of hyperoxia (80% oxygen) to Sprague-Dawley (SD) rats from P2 to P14 and then returned to normoxic conditions. TA was intravitreal-injected once into the right eye of OIR rats at P15. Effects of TA on vascular pathophysiology or changes of various genes in response to hypoxia and/or proinflammation under hypoxic retina were assessed by the Evans-blue method, fluorescein isothiocyanate-dextran (FITC-D) infusion, immunoblotting, and ELIZA. TA not only reduced retinal neovascularization and vascular leakage in the OIR-rat retina, but also blocked the induction of hypoxia-response proinflammatory genes before it negatively controlled VEGF activation. These findings suggest a potential that TA suppresses retinal neovascular pathophysiology via proinflammation-mediated activation of VEGF during hypoxia.

Contact dermatitis in Korean dental technicians.

The high risk of occupational contact dermatitis in dental personnel are well accepted throughout the world. There are few reports concerning occupational skin disease in dental personnel in Korea. The purposes of this study were to investigate the frequency, characteristics and causative factors of contact dermatitis in Korean dental technicians. Recording of personal history, physical examination and patch tests with the Korean standard series and dental screening series were performed in 49 dental technicians. Most of the subjects were exposed to a variety of compounds, including acrylics, metals, plaster, alginate, etc. 22 (44.9%) subjects had contact dermatitis, present or past, and the site involved was the hand in all 22. The most common clinical feature of hand dermatitis was itching (77.3%); scaling, fissuring and erythema were other common clinical features. Metals, including potassium dichromate (24.5%), nickel sulfate (18.4%), mercury ammonium chloride (16.3%), cobalt chloride (12.2%) and palladium chloride (10.2%), showed high positive rates in patch test results of 49 dental technicians. 7 positive reactions to the various acrylics were found in 3 subjects. In our study, the frequency and clinical features of the contact dermatitis showed a similarity to other reports, though the patch test results were somewhat different; a higher patch-positive reaction to metals and a relatively lower patch-positive reaction to acrylics than the patch test results reported in Europe.

Ethanol decreases the expression of mitochondrial cytochrome c oxidase mRNA in the rat.

To evaluate the molecular and cellular bases of effects of ethanol on the brain, we utilized a differential display-polymerase chain reaction. Several cDNA fragments were differentially expressed in the hippocampus of control vs. ethanol-treated rats. One of these genes was homologous to the rat mitochondrial cytochrome c oxidase mRNA. Northern blot analysis revealed that the expression of this message in the whole hippocampus was clearly lower after ethanol treatment. Using in situ hybridization, we also found that cytochrome c oxidase mRNA expression, especially in the CA1 and CA3 of the hippocampal regions, was significantly decreased by ethanol treatment. As cytochrome c oxidase is related to oxidative stress, the present study suggests that ethanol might affect the brain through modulation of an oxidative stress reaction.

Estudo clínico e laboratorial da neurocisticercose em Brasília

Este trabalho teve como objetivo analisar clínica e laboratorialmente pacientes com sintomatologia neurológica residentes em Brasília, identificando aqueles cujos sintomas eram decorrentes da neurocisticercose. Foram examinados 520 doentes, sendo 428 com epilepsia; 29 com hipertensäo intracraniana; e 63 com cefaléia resistente de causa näo identificada e/ou com calcificaçöes no estudo radiológico de crânio. Classificou-se a neurocisticercose nas seguintes formas: epiléptica; hipertensiva, subdividida nas formas hidrocefálica, pseudo-tumoral e tumoral; com cefaléia; apoplética; psíquica e raquidiana. Foram identificados 67 pacientes (12,9%) com neurocisticercose, sendo 35 (6,7%) com o diagnóstico confirmado por apresentarem um ou ambos testes imunológicos reagentes no líquor ou cistos intracranianos (Grupo A) e 32 (6,1%) por mostrarem calcificaçöes intracranianas e ambos testes imunológicos näo-reagentes no líquor (Grupo B). Entre os enfermos com cistos, 18,2% tiveram os testes imunológicos näo reagentes no líquor. As formas clínicas mais freqüentemente encontradas foram a epiléptica, quer seja isolada ou associada, surgiu em 62,7% dos pacientes e a hipertensiva, que foi encontrada em 34,3%. Foi observada maior freqüência da forma hipertensiva no Grupo A e da forma epiléptica no Grupo B. Encontraram-se ainda 13,4% dos doentes com a forma apoplética (associada ou isolada), 60% com cefaléia, 4,5% com a forma psíquica e 1,5% com a forma raquidiana...

Estudo clinico e laboratorial da neurocisticercose em Brasilia

Este trabalho teve como objetivo analisar clinica e laboratorialmente pacientes com sintomatologia neurologica residentes em Brasilia, identificando aqueles cujos sintomas eram decorrentes da neurocisticercose. Foram examinados 520 doentes, sendo: 428 com epilepsia; 29 com hipertensao intracraniana; e 63 com cefaleia persistente de causa nao identificada e/ou com calcificacao no estudo radiologico de cranio. Classificou-se a neurocisticercose nas seguintes formas: epileptica; hipertensiva, subdividida nas formas hidrocefalica, pseudotumoral e tumoral; com cefaleia; apopletica; psiquica e raquidiana. Foram identificados 67 pacientes (12,9 por cento) com neurocisticercose, sendo 35 (6,7 por cento) com o diagnostico confirmado por apresentarem um ou ambos testes imunologicos reagente no liquor ou cistos intracranianos (Grupo A) e 32 (6,1 por cento) por mostrarem calcificacoes intracranianas e ambos testes imunologicos nao-reagentes no liquor (Grupo B). Entre os enfermos com cistos, 18,2 por cento tiveram os testes imunologicos nao-reagentes no liquor. As formas clinicas mais frequentemente encontradas foram a epileptica, quer seja isolada ou associada, surgiu em 62,7 por cento dos pacientes e a hipertensiva, que foi encontrada em 34,3 por cento. Foi observada maior frequencia da forma hipertensiva no Grupo A e da forma epileptica no Grupo B. Encontraram-se ainda 13,4 por cento com a forma apopletica (associada ou isolada), 6,0 por cento com cefaleia, 4,5 por cento com a forma psiquica e 1,5 por cento com a forma raquidiana. Nos pacientes epilepticos, ambos os testes imunologicos foram reagentes no soro em 4,2 por cento e mostraram resultados discordantes em 4,0 por cento. Entre os 53 doentes que realizaram os testes imunologicos no liquor, 15,1 por cento foram reagentes e 1,9 por cento mostrou resultados discordantes entre os dois testes. Surgiu correlacao entre a presenca de anticorpos anti-Cysticercus no liquor e a faixa etaria de inicio dos sintomas. A epilepsia parcial ocorreu em maior frequencia nos pacientes com o liquor reagente. Ambos os testes imunologicos foram reagentes no liquor em 41,2 por cento dos doentes com a forma hidrocefalica, 12,5 por cento daqueles com a forma pseudotumoral e 50,0 por cento dos com a forma tumoral da cisticercose. Estes testes tiveram resultados discordantes no liquor em 27,6 por cento dos pacientes com hipertensao intracraniana, sendo que 20,7 por cento deles apresentavam a forma pseudotumoral. Uma ou ambas reacoes imunologicas foram reagentes no liquor em 52,9 por cento dos enfermos com hidrocefalia e 87,5 por cento daqueles com a forma pseudotumoral. A sorologia reagente predominou no sexo masculino nas formas hidrocefalica e tumoral e no feminino na forma pseudotumoral. Este estudo permitiu-nos concluir que a neurocisticercose tem grande prevalencia em Brasilia, apresentando-se em diferentes formas clinicas e mostrando sintomatologia polimorfa.