Methylene blue-related corneal edema and iris discoloration / Edema de córnea e descoloração de íris associados ao azul de metileno

ABSTRACT We report the case of a 70-year-old female patient who developed corneal edema and iris discoloration following the inadvertent use of 1% methylene blue instead of 0.025% trypan blue to stain the anterior capsule during cataract phacoemulsification surgery. Copious irrigation was performed upon realization of incorrect dye use. Corneal edema and iris discoloration developed during the early postoperative period and persisted at 24-months follow-up. However, keratoplasty was not required. The intracameral use of 1% methylene blue has a cytotoxic effect on the corneal endothelium and iris epithelium. Copious irrigation for at least 30 min using an anterior chamber maintainer may improve outcomes.

RESUMO Paciente do sexo feminino com 70 anos de idade desenvolveu edema da córnea e descoloração da íris após o uso inadvertido de 1% de azul de metileno em vez de 0,025% de azul tripano para corar a cápsula anterior do cristalino durante a cirurgia de catarata por facoemulsificação. Foi realizada irrigação abundante quando detectou-se que o corante incorreto tinha sido usado. Edema da córnea e descoloração íris que ocorreu no período pós-operatório precoce persistiu durante 24 meses de seguimento; no entanto, a ceratoplastia não foi necessária. O uso intracameral de 1% de azul de metileno tem efeitos citotóxicos sobre o endotélio da córnea e epitélio da íris. A irrigação abundante durante pelo menos 30 minutos, utilizando um mantenedor de câmara anterior pode resultar em um prognóstico melhor.

Desenvolvimento e testes in vitro de um novo corante para terapia fotodinâmica em Periodontia / Development and in vitro tests of a new dye for photodynamic therapy in Periodontics

A terapia fotodinâmica antimicrobiana (Antimicrobial Photodynamic Therapy - aPDT) tem sido utilizada em Periodontia para redução bacteriana de bolsas periodontais na forma de tratamento adjuvante da raspagem e alisamento radicular. Seu efeito em cirurgias periodontais é pouco estudado. Pesquisas recentes têm procurado descobrir novos fotossensibilizadores para aumento da efetividade dessa terapia. O objetivo do presente estudo foi testar in vitro um novo corante à base de corantes fenotiazínicos para uso em aPDT, quanto à sua biocompatibilidade e efetividade em eliminar bactérias. Foram realizados testes para avaliar a desmineralização e desgaste causados pelo corante em esmalte e dentina bovinos, bem como o tempo de aplicação ideal para se conseguir efeitos semelhantes ao ácido cítrico; comportamento óptico dos novos corantes em relação aos corantes convencionais; teste de biocompatibilidade de fragmentos de raiz humana, tratados pelo corante, em culturas de fibroblastos gengivais humanos; efetividade dos novos corantes sozinhos ou associados ao laser na eliminação de S. aureus e E. coli. Nos experimentos de desmineralização e biocompatibilidade foi utilizado um laser vermelho (660nm, 30mW, 45J/cm2, 30s) e nos experimentos com bactérias laser vermelho (660nm, 100mW, 45J/cm2, 12s). As análises estatísticas foram realizadas com testes paramétricos e não paramétricos (p<0,05). Os resultados mostraram que o novo corante promoveu desmineralização em esmalte (perda de dureza 55,5% e desgaste 10,33μm) e dentina (perda de dureza 65,9% e desgaste 8,37μm) bovinos de forma semelhante ao ácido cítrico, sendo 180s, o tempo mais adequado. Nos ensaios ópticos, observou-se que o novo corante à base de azul de toluidina (NCTBO) reduziu a banda de absorção para 575nm e teve uma fotodegradação mais rápida, enquanto que à base de azul de metileno (NCMB) o pico manteve-se em 660nm com fotodegradação lenta. O crescimento de fibroblastos gengivais humanos sobre superfícies de raiz...

The antimicrobial photodynamic therapy (aPDT) is used in Periodontics for reduction of bacteria in periodontal pockets as an adjuvant treatment to scaling and root planning. Recent researches aim at finding new photosensitizers in order to improve its effectiveness. The aim of this study was to test in vitro the biocompatibility and efficiency of eliminating bacteria of a new phenothiazine-based dye for aPDT in Periodontics. The following tests were performed: magnitude of demineralization and wear in bovine dentin and enamel fragments; the ideal time of application to obtain results similar to citric acid conditioning; optic behavior of new dye compared to conventional dyes; biocompatibility of human root fragments treated by the new dye in human gingival fibroblasts culture; effectiveness of the new dye in elimination of S. aureus and E. coli. In the experiments of demineralization and biocompatibility a red laser (660nm, 30mW, 45J/cm2, 30s) was applied, while in the microbiology experiments the parameters were changed (660nm, 100mW, 45J/cm2, 12s). The statistical analysis were done with parametric and non-parametric tests (p<0.05). The results showed that the new dye promoted demineralization in bovine enamel (surface hardness loss 55.5% and wear 10.33μm) and dentin (surface hardness loss 65.9% and wear 8.37μm). The demineralization was similar to citric acid and the ideal time of application was 180s. The optic tests showed that the toluidine blue-based new dye (TBOND) diminished the absorption band to 575nm and had a faster photodegradation. The methylene blue-based new dye (MBND) maintained a peak of absorption in 660nm and had a slower photodegradation. Growth of human gingival fibroblasts onto human root surfaces was similar to those treated with regular dyes (3.07 x 2.6 cells after 72h). The TBOND when used alone, reduced E. coli and S. aureus in 59.6% e 54.6%, respectively. When associated to laser, the reduction of E. coli was 52.6%. The MBND...

Evaluation of the safety of intracameral trypan blue injection on corneal tissue using oxidative stress parameters and apoptotic activity: an experimental study / Avaliação da segurança de injeção de azul de tripan intracameral no tecido da córnea utilizando parâmetros de estresse oxidativo e atividade apoptótica: um estudo experimental

Purpose: The present experimental study aimed to investigate the effects of intracameral trypan blue (TB) on oxidative stress parameters and apoptosis in corneal tissue. Methods: Thirty rats were randomly assigned to three groups of 10 rats each: the sham group (Group 1); control group (Group 2); and treatment group (Group 3). The control group was administered 0.01 cc of balanced salt solution. The treatment group was administered 0.006 mg/0.01 cc of TB. The total antioxidant status (TAS) and total oxidant status (TOS) in corneal tissue and blood were measured and the oxidative stress index (OSI) was calculated. Finally, corneal tissue histopathology was evaluated using staining for caspase-3 and -8, and apoptotic activity was examined. Results: The TAS, TOS and OSI levels in the blood samples were not significantly different (p>0.05 for all). Compared with the sham and control groups, the TOS and OSI levels in corneal tissue were significantly different in the treatment group (p<0.05 for all). No significant difference was observed between the sham group and the control group (p>0.05). Immunohistochemical staining for caspase-3 and caspase-8 demonstrated higher apoptotic activity in the TB group than in the sham and control groups. Conclusion: The present study showed that intracameral TB injection is safe systematically but may be toxic to corneal tissue, as demonstrated using oxidative stress parameters and histopathological evaluation. .

Objetivo: Este estudo experimental tem como objetivo investigar os efeitos do azul de tripan intracameral (TB) sobre parâmetros de estresse oxidativo e apoptose no tecido da córnea. Métodos: Trinta ratos foram divididos aleatoriamente em três grupos de 10 animais cada: grupo simulação (Grupo 1); grupo controle (Grupo 2); e grupo tratamento (Grupo 3). No grupo controle foi administrado 0,01 cc de solução salina balanceada (BSS). No grupo tratamento foi administrado 0,006 mg/0,01 cm de TB. O estado antioxidante total ( TAS) e estado oxidante total ( TOS) no tecido da córnea e sangue foram medidos e o índice de estresse oxidativo (OSI) foi calculado. Finalmente, histopatologia do tecido da córnea foi avaliada por meio da coloração para caspase-3 e -8; atividade apoptótica também foi examinada. Resultados: Os níveis de TAS, TOS e OSI das amostras de sangue não foram significativamente diferentes (p>0,05 para todos). Em comparação com os grupos simulação e controle, os níveis de TOS e OSI no tecido da córnea foram significativamente diferentes no grupo tratamento (p<0,05 para todos). Não houve diferença significativa entre o grupo simulção e o grupo controle (p>0,05). A coloração imuno-histoquímica com a caspase-3 e caspase-8 demonstrou maior atividade apoptótica no grupo tratamento do que nos grupos controle e simulação. Conclusão: Este estudo mostrou que a injeção intracameral TB é segura sistematicamente, mas pode ser tóxica ao tecido da córnea, como demonstrado através de parâmetros de estresse oxidativo e avaliação histopatológica. .

Permeability of different groups of maxillary teeth after 38 percent hydrogen peroxide internal bleaching

This study evaluated the influence of internal tooth bleaching with 38 percent hydrogen peroxide (H2O2) on the permeability of the coronal dentin in maxillary anterior teeth and premolars. Seventy teeth (14 per group) were used: central incisors (CI), lateral incisor (LI), canines (C), first premolars (1PM) and second premolars (2PM). Pulp chamber access and transversal sectioning at 2 mm from the cementoenamel junction were performed and the specimens were divided into 2 groups (n= 7): a) no treatment and b) bleaching with 38 percent H2O2. The bleaching agent was applied to the buccal surface and to the pulp chamber for 10 min. This procedure was repeated 3 times. The specimens were processed histochemically with copper sulfate and rubeanic acid, sectioned longitudinally, and digitalized in a scanner. The area of stained dentin was measured using Image Tool software. Data were analyzed statistically by ANOVA and Tukey's HSD test (?=0.05). There was statistically significant difference (p<0.001) among the untreated groups, CI (0.23 ± 0.26) having the lowest permeability and LI (10.14 ± 1.89) the highest permeability. Among the bleached groups, dentin permeability was increased in all groups of teeth except for 2PM. It may be concluded that bleaching with 38 percent H2O2 affected dentin permeability near the pulp chamber in maxillary anterior teeth and in first and second premolars.

Este estudo avaliou a influência do clareamento interno com peróxido de hidrogênio (H2O2) a 38 por cento na permeabilidade da dentina coronária de dentes anteriores superiores e pré-molares superiores. Quatorze incisivos centrais (IC), incisivos laterais (IL), caninos (C), primeiros (1PM) e segundos (2PM) pré-molares foram seccionados transversalmente e distribuídos em 2 grupos (n=7) sendo: G1: não receberam tratamento e, G2: clareados com aplicação de gel na face vestibular e câmara pulpar por 10 min, repetido 3 vezes. Os espécimes foram processados histoquimicamente por meio de imersão em sulfato de cobre e ácido rubeânico e digitalizados em escaner. A área corada foi aferida (Programa Image Tool). Os dentes que não receberam tratamento, apresentaram diferença estatisticamente significante (p<0,001), sendo o ICS (0,23 ± 0,26) e o ILS (10,14 ± 1,89) os grupo com os menores e os maiores valores de permeabilidade, respectivamente. Quando clareados, a permeabilidade coronária dos grupos dentais foi aumentada, exceto no grupo do 2PM. Concluiu-se que a permeabilidade da dentina coronária nos dentes anteriores superiores e primeiros pré-molares foi alterada pelo clareamento dental interno.

Risco de contaminacão do corante azul de tripano após primeira utilizacão / Risk of contamination of trypan blue dye after first use

OBJETIVOS: Determinar o potencial risco de contaminacão do frasco de azul de tripano (AT) depois de utilizado pela primeira vez e estocado em diferentes condicões de temperatura e umidade, assim como identificar os possíveis fatores de contaminacão, microrganismos mais freqüentemente envolvidos e simultaneamente avaliar as propriedades bacteriostáticas e bactericidas do corante. MÉTODOS: Realizado estudo experimental, prospectivo, em que 30 frascos de AT foram divididos em três grupos (A: controle, B: armazenamento em geladeira e C: armazenamento em armário). O corante era aspirado e semeado em placas de ágar sangue e tubo de ágar Sabouraud. No grupo A o AT foi semeado apenas logo após a abertura dos frascos (tempo zero - T0), nos grupos B e C ocorreu semeadura nos T0, T1 (1 dia), T2 (2 dias), T7 (7 dias) e T10 (10 dias) após abertura dos frascos. No 10º dia os frascos dos grupos B e C também foram submetidos a um raspado do lado interno do frasco após abertura. Concomitantemente foi realizado teste de acão inibitória do corante AT para estudo da atividade bacteriostática e bactericida. RESULTADOS: As semeaduras realizadas no T0 não apresentaram contaminacão. Entre os T1 e T10 mais o raspado houve apenas 1 frasco contaminado armazenado em geladeira. O microrganismo encontrado foi o Aspergillus niger. Foi comprovado que o corante não apresenta acão bactericida e bacteriostática para as bactérias testadas. CONCLUSÕES: Nas condicões do estudo não houve contaminacão dos frascos armazenados em armário e 1 frasco (10 por cento) armazenado em geladeira apresentou contaminacão após abertura e uso inicial. A fonte de contaminacão talvez seja o lado externo do produto. O AT não apresenta propriedades bactericidas e bacteriostáticas para as bactérias testadas e na concentracão utilizada.

Extraction of heparin and heparin-like substance from marine mesogastropod mollusc Turritella attenuata (Lamarck, 1779).

Heparin was extracted from marine gastropod T. attenuata through the sequential precipitation with methanol and ethanol. The metachromatic dye method using toluidine blue was used to estimate colorimetrically the amount of heparin present in the sample. The anticoagulant activity of the sample was calculated as per United States of Pharmacopoeia standard procedure using sheep blood. After the purification, samples were analyzed, for the presence of heparin, with agarose-gel electrophoresis and HPLC and the mobility of the sample and the peak respectively were compared with standard heparin. The results of the present study shall help in finding out alternate source.

Comparative immunogenecity of foot and mouth disease virus antigens in FMD-haemorrhagic septicaemia combined vaccine and FMD vaccine alone in buffalo calves.

Humoral immune response was evaluated by monitoring the serum antibody titres and virus specific IgM titres against Foot and Mouth Disease (FMD) virus antigens in serum samples obtained from different groups of calves inoculated with combined vaccine or FMD vaccine alone, on 0, 7, 14, 21, 28, 42 and 56 days post-vaccination (DPV). The cellular immune response was monitored by MTT based lymphoproliferation in peripheral blood mononuclear cell cultures. Higher liquid phase blocking (LPB) ELISA antibody titres were observed in calves receiving combined vaccine as compared to calves immunized with FMD vaccine alone with the peak titres in both the groups obtained on 21 days post-vaccination. However, the virus specific IgM titres were significantly higher in group of calves inoculated with combined vaccine than FMD vaccine alone. The lymphoproliferative responses against FMDV types O, A22 and Asia 1 in the groups receiving combined vaccine and FMD vaccine alone started increasing gradually after day 14 and reached peak levels on 28 DPV followed by a gradual decline subsequently. The group receiving combined vaccine showed higher proliferative responses on in vitro stimulation with FMD virus type O, whereas, with FMD virus type Asia 1, the responses were significantly higher on 14 and 21 DPV as compared to the group immunized with FMD vaccine alone. However, in the group receiving combined vaccine, the responses on in vitro stimulation with FMD virus type A22 were significantly higher than FMD vaccine alone group on all DPV except on 42 DPV.

Effect of metanil yellow and malachite green on DNA synthesis in N-nitrosodiethylamine induced preneoplastic rat livers.

Metanil yellow (MY) and malachite green (MG) are textile dyes, which, despite the ban occurs unsrupulously as food colouring agents. Accordingly they constitute a serious public health hazard and are of sufficient environmental concern. We have earlier reported that both MY and MG have tumor enhancing effects on the development of hepatic preneoplastic lesions induced by N-nitrosodiethylamine in rats. In order to understand the possible mechanisms by which MY and MG enhance tumor development, in this study we have tested the effects of MY and MG on DNA synthesis and PCNA expression in preneoplastic hepatic lesions during N-nitrosodiethylamine (DEN) induced hepatocarcinogenesis in male Wistar (WR) rats. Rats were administered 200 ppm DEN through drinking water for a period of one month. Administration of DEN for a period of one month showed an upregulation of cell cycle regulatory proteins namely cyclin D1, CDK4, cyclin E and CDK2. Accordingly, in other experiments, the animals were further administered MY and MG for a period of one month following one month DEN treatment. The effects of MY and MG were monitored on the basis of cell proliferation markers--DNA synthesis and PCNA expression both by immunohistochemical and immunoblotting. Following DEN administration, MY, MG and PB showed stimulation of DNA synthesis and increased PCNA expression when compared with either the corresponding controls or only DEN treated animals. In the present study, enhancing effect of MY, MG and PB on the cell proliferation markers during DEN-induced hepatic preneoplasia in rats was observed.

Genotoxic evaluation of the effect of Thuya occidentalys tinctures

Three tinctures samples from extracts of the popular medicinal plant Thuya occidentalis were tested in vitro through two short term tests for measuring the activity of genotoxic chemicals. Using the Salmonella/mammalian-microsome (Mutatest) assay and the SOS-chromotest (induction of beta-galactosidase in Escherichia coli), none of the extract was effective in inducing mutagenesis or beta-galactosidase synthesis (as an indicator of general and early sign of DNA damage), even with metabolization

Role of bradykinin in postprandial hypotension in humans

A transient significant decrease in mean arterial blood pressure (MAP) from 107 + ou - 3 to 98 + ou - 3 mmHg (P<0.05) was observed in elderly (59-69 years of age), healthy volunteers 25-30 min following ingestion of a test meal. In young volunteers (22-34 years of age), a postprandial decrease of MAP from 88 + ou - 3 to 83 + ou - 4 mmHg was also noted but it was not statistically significant. A 40 per cent decrease in bradykinin (BK) content of circulatory high molecular weight kininogen had previously been observed in human subjects given the same test meal. We presently demonstrate by specific ELISA that the stable pentapeptide metabolite (1-5 BK) of BK increases from 2.5 + ou - 1.0 to 11.0 + ou - 2.5 pg/ml plasma (P<0.05) in elderly volunteers and from 2.0 + ou - 1.0 to 10.3 + ou - 3.2 pg/ml plasma (P<0.05) in young volunteers 3 h following food intake. This result suggests that ingestion of food stimulates BK release from kininogen in normal man. Postprandial splanchnic vasodilatation, demonstrated by a decrease of plasma half-life of intravenously administered indocyanine green (ICG), a marker of mesenteric blood flow to the liver, from 4.4 + ou - 0.4 to 3.0 + ou - 0.1 min (P<0.05) in young volunteers and from 5.2 + ou - 1.0 to 4.0 + ou - 0.5 min (P<0.05) in elderly volunteers, accompanied BK release. The participation of BK in this response was investigated in subjects given the BK-potentiating drug captopril prior to food intake. Postprandial decreases of ICG half-lives were not changed by this treatment in either young or elderly subjects, a result which may indicate that BK released following food intake plays no role in postprandial splanchnic vasodilatation in normal man.

Effects of trypan blue on the action of adrenergic agonists in the guinea-pig isolated atrium.

It has been reported that trypan blue, a diazo dye with polyamphipathic structure, can inhibit the coupling of receptors to G-proteins. The present study was carried out to investigate the effect of trypan blue on the actions of adrenoceptor agonists in the guinea-pig atrium. Trypan blue (10 and 100 microM) antagonized the positive inotropic effects of isoprenaline and dobutamine by shifting their concentration-response curves to the right. With the selective beta 2-adrenoceptor agonist, salbutamol, there was a reduction of response in the presence of trypan blue. Therefore, we concluded that trypan blue diminish the response to beta-adrenoceptor agonists possibly via decoupling receptors from Gs. Trypan blue and similar agents, due to their unique mode of action, can be used as tools for the investigation of the mechanism of receptor-G protein coupling in the whole tissue preparation.

Toxicidad en dosis repetidas del Oncidium luridum Lindl / Toxicity by repeated doses of Oncidium luridum Lindl

Se realizó un estudio de toxicidad subcrónica en ratas Wistar mediante la administración oral de una tintura de orquídea silvestre. La experiencia duró 45 días; se realizó examen físico diario individual y se controló semanalmente el consumo de agua, alimentos y peso corporal. Se midieron algunas variables sanguíneas al inicio de la experiencia y final de ésta que nos sirvieron como marcadores fisiológicos de órganos y sistemas. Se realizó necropsia a todos los animales, tomando muestras de los principales órganos para su histología. Durante la evolución no se apreciaron signos de intoxicación. Se observó disminución de la variable hemoglobina y aumento de los niveles de glucosa en sangre en todos los grupos, lo cual consideramos que no guarda relación con el producto. Además, se observó que el nivel de colesterol se mantuvo elevado en los grupos controles, no sucedió así con los grupos experimentales. La histología no arrojó lesiones tóxicas