Surface-enhanced Raman scattering (SERS) applied to cancer diagnosis and detection of pesticides, explosives, and drugs

The inelastic scattering of light, Raman scattering, presents a very low cross section. However, the signal can be amplified by several orders of magnitude, leading to the so-called surface-enhanced Raman scattering (SERS) phenomenon. Basically, the SERS effect is achieved when the target molecule (analyte) is adsorbed onto metallic nanoparticles, usually noble metals. This article presents an overview of the applications of SERS to cancer diagnosis and the detection of pesticides, explosives, and drugs (illicit and pharmacological). SERS is routinely applied nowadays to detect and identify analytes at very low concentrations, including for single-molecule detection. However, the application of SERS as an analytical tool requires reliable and reproducible SERS substrates, in terms of enhancement factors, which depends on the size, shape, and aggregation of the metallic nanoparticles. Therefore, the production of reliable and reproducible SERS substrates is a challenge in the field. Besides, the metallic nanoparticles can also induce changes in the system by possible interactions with the analyte under investigation, which must be taken into account. This review will present work in which, under certain specific experimental conditions, SERS has been analytically applied.

A mini review of Candida species in hospital infection: epidemiology, virulence factor and drugs resistance and prophylaxis

The introduction of more efficient diagnostic methods, new techniques in surgery and transplantation, antibiotics and chemotherapeutics more potent and novel materials for prostheses, catheters and probes significantly increased the life expectancy and quality of life of critically ill patients, on the other hand, hospital-acquired infections emerged as important iatrogenic complications. Invasive infections are a growing problem in public health hospitals in Brazil and worldwide. Among the various etiological agents found in the hospital environment, the genus Candida has been the third most frequently isolated pathogen. In general, invasive fungal infections are associated with high morbidity and mortality, difficulties in diagnosis, antimicrobial resistance, length of hospital stay and increased hospital costs. This mini review of the literature describes about epidemiology of hospital infection of Candida species, as well as its virulence factors and drugs resistance

Study of the interaction between cardiolipin bilayers and methylene blue in polymer-based Layer-by-Layer and Langmuir films applied as membrane mimetic systems

An increase of the reports involving mimetic systems has been observed. Briefly, these systems use biological phospholipids to exploit specific interactions between membrane-models and drugs. Here, the Layer-by-Layer (LbL) and Langmuir techniques were used to investigate the interaction between cardiolipin (CLP-negative phospholipid) and a cationic-like drug methylene blue (MB). Supported by a cationic polyelectrolyte (PAH), LbL films containing PAH/(CLP + MB) and PAH/(CLP + MB + AgNP) were grown up to 14 bilayers. The optical microscopy analysis revealed a decrease of the CLP vesicle sizes in the presence of MB as a possible consequence of the MB action onto the mechanical properties of the CLP membrane. From FTIR spectra, changes mainly related to peak position and band intensity and shape were observed in the spectra from PAH/CLP when in the presence of MB. The latter supports that the interactions between the phosphate and amine charged groups from CLP and PAH, respectively, established during the LbL film fabrication, besides the CLP hydrocarbon environment, are influenced by the presence of MB. Using the micro-Raman technique, a chemical mapping was build based on MB spectrum by resonance Raman scattering (RRS) and surface-enhanced resonance Raman scattering (SERRS). The later phenomenon was activated by Ag nanoparticles (AgNPs) trapped within the LbL film allowing collecting spectra for a single bilayer of PAH/(CLP + MB + AgNP). A rough estimation showed a SERRS amplification of 10(3) in comparison to RRS spectra. As a complementary approach, Langmuir films of CLP in the presence of co-spread MB were investigated through surface pressure vs mean molecular area (pi-A) isotherms. The results showed that for concentrations of MB below 100 mol%, the drug is expelled to water subphase for high values of surface pressure (condensed phase). For concentration at 100% and higher, the MB keeps bound to CLP floating monolayer. (C) 2010 Elsevier B.V. All rights reserved.

Remoção de diclofenaco, ibuprofeno, naproxeno e paracetamol em filtro ecológico seguido por filtro de carvão granular biologicamente ativado

O filtro ecológico representa uma promissora tecnologia de tratamento, em razão desta não necessitar da aplicação de produtos químicos, além de sua constatada eficiência. Nele, estabelece-se entre os seres vivos a relação de cadeia alimentar. Inicialmente uma matriz aquosa foi acrescida de quatro fármacos (diclofenaco, naproxeno, ibuprofeno e paracetamol) e posteriormente analisada por cromatografia líquida de alta eficiência para avaliar a remoção desses compostos pelo filtro ecológico seguido pelo filtro de carvão granular biologicamente ativado. Parâmetros, entre eles turbidez, coliformes totais e termotolerantes, cor aparente e cor verdadeira, foram mensurados para verificar a eficiência dos filtros. Houve remoção de 97,43% do diclofenaco, 85,03% do ibuprofeno: 94,11% do naproxeno e 84,07% do paracetamol.

Preparation of different basic Si-MCM-41 catalysts and application in the Knoevenagel and Claisen-Schmidt condensation reactions

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Ischemia and reperfusion in skin flaps: effects of mannitol and vitamin C in reducing necrosis area in a rat experimental model

OBJETIVO: Neste trabalho foi padronizado modelo experimental de isquemia e reperfusão em retalho cutâneo em ratos no qual estudou-se possibilidade de uma solução antioxidante, composta por Ringer lactato, vitamina C e manitol de reduzir a área de necrose. MÉTODOS: O modelo consistiu de levantamento de retalho cutâneo axial de 6,0 x 3,0cm, submetido à isquemia de 8 horas e reperfusão de 7 dias. Os animais foram divididos em quatro grupos: grupos S1, S2 (10 animais cada), C e T (14 animais cada). Nos grupos S1 e S2 todos os procedimentos dos demais grupos foram efetuados, exceto a isquemia e reperfusão: S1 recebeu apenas Ringer lactato e S2 a solução antioxidante. Os grupos C e T foram submetidos à isquemia. O grupo C recebeu somente Ringer lactato e o grupo T a solução antioxidante. No 7(0) dia de pós-operatório as áreas de necrose e pele viável do retalho foram delineadas em decalque de acetato, os quais foram por sua vez analisados em sistema computadorizado KS-300 (Carl Zeiss). RESULTADOS: A análise estatística mostrou que não houve diferenças significativas entre o grupo tratado e controle quanto à área de necrose. CONCLUSÃO: Concluiu-se que o modelo experimental é consistente, determinando área de necrose limitada e uniforme nos animais não tratados e que as drogas usadas, nessa posologia e modo de aplicação, não foram efetivas em diminuir a área de necrose no modelo experimental em questão.

Kinetics and crystal structure of human purine nucleoside phosphorylase in complex with 7-methyl-6-thio-guanosine

Purine nucleoside phosphorylase (PNP) catalyzes the reversible phosphorolysis of nucleosides and deoxynucleosides, generating ribose 1-phosphate and the purine base, which is an important step of purine catabolism pathway. The lack of such an activity in humans, owing to a genetic disorder, causes T-cell impairment, and drugs that inhibit this enzyme may have the potential of being utilized as modulators of the immunological system to treat leukemia, autoimmune diseases, and rejection in organ transplantation. Here, we describe kinetics and crystal structure of human PNP in complex with 7-methyl-6-thio-guanosine, a synthetic substrate, which is largely used in activity assays. Analysis of the structure identifies different protein conformational changes upon ligand binding, and comparison of kinetic and structural data permits an understanding of the effects of atomic substitution on key positions of the synthetic substrate and their consequences to enzyme binding and catalysis. Such knowledge may be helpful in designing new PNP inhibitors. © 2005 Elsevier Inc. All rights reserved.

In Vitro and In Vivo Activities of Ruthenium(II) Phosphine/Diimine/Picolinate Complexes (SCAR) against Mycobacterium tuberculosis

Rifampicin, discovered more than 50 years ago, represents the last novel class of antibiotics introduced for the first-line treatment of tuberculosis. Drugs in this class form part of a 6-month regimen that is ineffective against MDR and XDR TB, and incompatible with many antiretroviral drugs. Investments in R&D strategies have increased substantially in the last decades. However, the number of new drugs approved by drug regulatory agencies worldwide does not increase correspondingly. Ruthenium complexes (SCAR) have been tested in our laboratory and showed promising activity against Mycobacterium tuberculosis. These complexes showed up to 150 times higher activity against MTB than its organic molecule without the metal (free ligand), with low cytotoxicity and high selectivity. In this study, promising results inspired us to seek a better understanding of the biological activity of these complexes. The in vitro biological results obtained with the SCAR compounds were extremely promising, comparable to or better than those for first-line drugs and drugs in development. Moreover, SCAR 1 and 4, which presented low acute toxicity, were assessed by Ames test, and results demonstrated absence of mutagenicity. © 2013 Pavan et al.

Falência hepática aguda: caracterização e quantificação dos tipos celulares envolvidos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Drug addictions and sexual violence in childhood and adolescence: analyzing life stories

The sexual abuse suffered in childhood and adolescence, in addition to damage to physical and psychological health of the victim, is considered as an important risk factor for alcohol and drugs addiction, development of psychopathology and psychosocial damage in adulthood. In addition to the pain and humiliation that are submitted by the abuse, children and adolescents also experience shame and guilt which require them to adopt coping strategies to endure those feelings. The use of psychoactive substances is a recognized way of dealing with the pains of living. This work, which is of narrative style, analyses and discusses, through five case reports, chemical dependency as a result of sexual abuse suffered in childhood and/or adolescence. The eight subjects in this study are male and have suffered sexual violence in this age period of life. Their ages range from 23 years to 39 years, and all are admitted to a therapeutic community in a city in the interior of Sao Paulo state, in Brazil, for treatment of chemical dependency, being met by the Department of Psychology. The reasons for the choice of the participants for treatment modality for patients are: difficult to stop using drugs, even unwilling to take it, they have easy access to it; the feeling of losing control over their lives; by successive losses as a result of drug use, and for fear that their lives had a tragic ending. With the exception of two participants, the others do not classify that as a child suffered sexual violence. However, all attribute that facilitated their entry into the world of drugs. Seven participants experienced such violence in childhood (between 7 years and 9 years) and adolescence (age 14). The attackers were people closed to the victims—in the case of two victims, their families, with the exception of one participant who was raped by a stranger. Six participants declared themselves as homosexual. Another participant does not claim to be homosexual, but presents difficulties in terms of sexuality. Two participants are HIV positive. The start of psychoactive substances use occurred during adolescence (12 years to 17 years). The participants see drugs as an anesthetic to the pain of the soul, a way to get pleasure, but they get charged expensively, as it increases the feeling of emptiness, guilt, helplessness, worthlessness and hopelessness. Although participants have sought help to deal with addiction, it is noted that throughout the life course the issue of sexual violence was not treated. It was noted that the patients have a double stigma in society: the issue of drugs addiction and the orientation of sexual desire, because the majority of participants are homosexual. The results reinforce the need for effective action geared to accommodate the victims of sexual violence and effective preventive measures to prevent children and adolescents from being abused.

Fish immunology: the modification and manipulation of the innate immune system: Brazilian studies

The understanding of fish immune system structure and function is essential for the development of new technologies and products to improve productivity. This is the first review on immune system of fish with Brazilian studies. Aquaculture in Brazil has shown massive growth in recent years due to methods of culture intensification. However, these procedures led to disease outbreaks, as well as the chemotherapy and the misuse of antibiotics. A viable alternative to avoid the use of chemicals and prevent economic losses is the administration of immunostimulants and prebiotcs, which act by increasing the innate immune system. In Brazil there is a lack of studies on fish immune system, except by some groups that have studied the effects of the immunostimulants administration in various species.

Peritoneal response to abdominal surgery: the role of equine abdominal adhesions and current prophylactic strategies

Intra-abdominal adhesions constitute a significant clinical and surgical problem that can lead to complications such as pain and bowel occlusion or subocclusion. These adhesions are frustrating and potentially fatal, representing a major postoperative complication in abdominal surgery. It is estimated that 32% of horses undergoing laparotomy will present clinical symptoms due to adhesions, but the true prevalence is not known because a large proportion of animals with postoperative recurrent colics are medically treated or submitted to euthanasia without necropsy. Adhesions are highly cellular, vascularized, dynamic structures that are influenced by complex signaling mechanisms. Understanding their pathogenesis could assist in applying better therapeutic strategies and in developing more effective antiadhesion products. Currently, there are no definitive strategies that prevent adhesion formation, and it is difficult to interpret the results of existing studies due to nonstandardization of an induction model and evaluation of their severity. The best clinical results have been obtained from using minimally traumatic surgical techniques, anti-inflammatory agents, antimicrobials, anticoagulants, and mechanical separation of serosal surfaces by viscous intraperitoneal solutions or physical barriers. This paper aims to review adhesion formation pathogenesis, guide the understanding of major products and drugs used to inhibit adhesion formation, and address their effectiveness in the equine species.

Uso de medicações por via subaracnóidea no tratamento da dor crônica

JUSTIFICATIVA E OBJETIVOS: A dor crônica é um desafio para a Medicina atual. Novos métodos e medicamentos têm sido propostos com o intuito de controlar os sintomas álgicos. A via de administração subaracnóidea tem se mostrado como uma alternativa viável e segura, embora necessite continuamente ser objeto de estudo de muitos pesquisadores. O objetivo deste trabalho é fazer uma revisão dos medicamentos disponíveis no arsenal terapêutico já consagrados pelo uso e os que se mostram promissores na atualidade para a prática clínica diária. CONTEÚDO: Nesta revisão são avaliados vários fármacos que apresentam ação analgésica quando utilizada via neuroeixo. Opióides, anestésicos locais, agonistas alfa2-adrenérgicos, antagonistas dos aminoácidos excitatórios e inibitórios, acetilcolina, inibidores da acetilcolinesterase, bloqueadores dos canais de cálcio, adenosina, serotonina, antidepressivos tricíclicos e inibidores da síntese de prostaglandinas são analisados no que concerne aos seus efeitos farmacológicos, incluindo os indesejáveis. CONCLUSÕES: Muitos avanços foram registrados no controle dos sintomas álgicos após a utilização das substâncias citadas por via raquidiana, onde certamente algumas serão aproveitadas e enriquecerão o arsenal terapêutico e outras relegadas temporária ou definitivamente. Entretanto, ainda serão necessários muitos estudos clínicos e experimentais para que estes conhecimentos possam ser incorporados e utilizados com segurança pelos profissionais que lidam com o tratamento da dor crônica.

Lupus eritematoso sistêmico: novo fator de risco para aterosclerose?

OBJETIVO: Avaliar a prevalência de eventos cardiovasculares (ECV) secundários à aterosclerose em pacientes com lupus eritematoso sistêmico (LES) e correlacioná-los aos tradicionais fatores de risco, tempo de doença e drogas utilizadas na terapia. MÉTODOS: Estudo retrospectivo através da coleta e análise dos dados contidos nos prontuários de pacientes com diagnóstico confirmado há no mínimo dois anos e seguidos desde 1992. Foram considerados ECV: angina do peito (AP), IAM e acidente vascular cerebral (AVC) de causa não relacionada à atividade do LES. Foram computados os fatores de risco para aterosclerose e dados sobre tratamento. RESULTADOS: Foram analisados 71 prontuários. A média de idade dos pacientes foi de 34,2±12,7 anos; 68 mulheres e três homens; 58 caucasóides (81,6%). Dez (14,08%) apresentaram ECV. Os pacientes nos quais os eventos cardiovasculares foram observados apresentavam idade mais elevada (42,7 vs 32,8 anos p=0,0021) e maior tempo de doença (10,8 vs 7,2 anos p=0,011). Os tradicionais fatores de risco, as doses diárias e cumulativas de esteróides, imunossupressores e antimaláricos não apresentaram diferença estatística significante entre pacientes que apresentaram ou não ECV. CONCLUSÃO: A prevalência de secundários à aterosclerose no LES foi semelhante ao da literatura, 14,08%. Os tradicionais fatores de risco não mostraram associação com a ocorrência ou não de ECV no LES. Os pacientes nos quais os eventos cardiovasculares foram observados apresentavam idade mais elevada e maior tempo de doença. É precoce estabelecer-se que o LES possa ser um fator independente no desenvolvimento da aterosclerose.