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INTRODUCTION: Brachial plexus reconstruction with free functional muscle transfers (FFMT) has become a reliable tool in the armamentarium of brachial plexus surgeon (Potter and Ferris, The Journal of hand surgery, European volume, 2017, 42,693-9). The successful execution of performing FFMT relies on favourable motor nerves for coaptation and appropriate vessels for microvascular anastomoses. Due to shared traumatic aetiology, subclavian and axillary vascular injury (SAVI) can coexist with the brachial plexus palsy and may pose a surgical dilemma with such FFMT execution. METHOD: We performed a retrospective study of 100 consecutive patients who presented to our hospital with brachial plexus injury over a 10-year period. Patient records were reviewed for concomitant SAVI and subsequent treatment that was required for both vascular (SAVI) and brachial plexus injuries (BPI). RESULTS: Concomitant BPI and SAVI occurred in 27% of patients. Open injuries predicted significantly higher rates of SAVI as well as complete plexus palsy. Complete plexus palsy was associated at a higher rate in the SAVI group compared to the non-SAVI group. CONCLUSION: Coexistence of SAVI and BPI is frequent. Complete plexus palsy and SAVI are more common in open injuries in this study. Complete plexus palsy is the most common indication for FFMT in BPI. Surgical execution of FFMT is more challenging in the setting of previous SAVI and requires careful consideration of the microsurgical plan. We recommend that all patients with previous SAVI or potential need for FFMT in this setting undergo vascular imaging at the time of acute injury and prior to any free flap reconstructive procedures.
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Traumatismos do Braço , Plexo Braquial , Lesões do Sistema Vascular , Plexo Braquial/cirurgia , Humanos , Incidência , Paralisia , Estudos Retrospectivos , Lesões do Sistema Vascular/complicações , Lesões do Sistema Vascular/epidemiologia , Lesões do Sistema Vascular/cirurgiaRESUMO
No abstract present.
Assuntos
Plasticidade Celular , Linfócitos T , Tolerância Imunológica , Transdução de SinaisRESUMO
BACKGROUND: Cancer is a multistep process involving genetic and epigenetic changes in the somatic genome. Genetic mutations as well as environmental factors lead to the initiation, promotion, and progression of cancer. Metastasis allows cancer cells to spread via circulatory and lymphatic systems; secondary tumorigenesis typically leads to a fatal outcome. Recent experimental evidence suggests that Cancer Stem Cells (CSCs) play a pivotal role in tumor progression. A tumor is heterogeneous and composed of different cell types. CSCs are a subpopulation of tumor cells possessing abilities to self-renew and differentiate. OBJECTIVE: The aim of this study was to present repurposed drugs, and potential candidates, that can serve as anticancer medications intended to target resistant cancer cells, i.e. CSCs. METHODS: Research publications, FDA filings, and patents have been reviewed for repurposed drugs or drug combinations that can act to improve cancer treatment and care. RESULTS: Drugs that act against CSCs include ones approved for treatment of diabetes (metformin & thiazolidinediones), parasitic diseases (chloroquine, niclosamide, mebendazole & pyrvinium), psychotic disorders (thioridazine, clomipramine & phenothiazines), alcoholism (disulfiram), lipid disorder (statins), inflammatory diseases (tranilast, auranofin, acetaminophen & celecoxib), antibiotics (azithromycin), and other disorders. Current research findings advocate the existence of beneficial effects by combining these repurposed drugs, and also through their complementary use with conventional cancer therapies. CONCLUSION: Repurposing FDA-approved medications towards cancer care, by targeting the resistant CSCs, will allow for a quicker, cheaper development and approval process. A larger drug library available to physicians will allow for increased efficacy during both first-line and recurrent cancer treatments.
Assuntos
Antineoplásicos/farmacologia , Neoplasias/tratamento farmacológico , Células-Tronco Neoplásicas/efeitos dos fármacos , Animais , Reposicionamento de Medicamentos , Resistencia a Medicamentos Antineoplásicos , Epigênese Genética , Humanos , Mutação , Neoplasias/genética , Neoplasias/patologia , Patentes como AssuntoRESUMO
BACKGROUND: Predicting cup size after reduction mammaplasty is a challenge well recognized by plastic surgeons. This study presents a method whereby the weight of tissue to be excised can be predicted on the basis of the initial and desired cup size. METHODS: Breast density was calculated from resection specimens. Cup volumes of a specific range of bra style were then measured by filling the bra cups with modeling clay on a mannequin and the volume measured via water displacement. These data were then correlated to breast tissue volume and weight. RESULTS: The average breast tissue density calculated was 0.98 g/ml (SD = 0.05). Bra cup volume measurements showed a steady progression according to both cup and band sizes. A table was constructed to predict the weight of tissue required for excision to achieve the desired change in cup size. CONCLUSION: These results can assist plastic surgeons in predicting the amount of breast tissue to excise to achieve a given cup size. A secondary use of these results is a breast volume guide for implant planning.
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Diet and microbiota each have a direct impact on many chronic, inflammatory, and metabolic diseases. As the field develops, a new perspective is emerging. The effects of diet may depend on the microbiota composition of the intestine. A diet that is rich in choline, red meat, dairy, or egg may promote the growth, or change the composition, of microbial species. The microbiota, in turn, may produce metabolites that increase the risk of cardiovascular disease. This article reviews our current understanding of the effects of the molecule trimethylamine-N-oxide (TMAO) obtained from food or produced by the microbiota. We review the mechanisms of actions of TMAO, and studies that associate it with cardiovascular and chronic kidney diseases. We introduce a novel concept: TMAO is one among a group of selective uremic toxins that may rise to high levels in the circulation or accumulate in various organs. Based on this information, we evaluate how TMAO may harm, by exacerbating inflammation, or may protect, by attenuating amyloid formation, in autoimmune diseases such as rheumatoid arthritis.
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Artrite Reumatoide/fisiopatologia , Doenças Autoimunes/fisiopatologia , Dieta , Metilaminas/farmacologia , Microbiota/fisiologia , Amiloide/metabolismo , Animais , Doenças Cardiovasculares/etiologia , Disbiose/fisiopatologia , Intolerância à Glucose , Humanos , Inflamação/etiologia , Metilaminas/metabolismo , Insuficiência Renal Crônica , Fatores de RiscoRESUMO
We took an experimental database mining analysis to determine the expression of 28 co-signaling receptors in 32 human tissues in physiological/pathological conditions. We made the following significant findings: 1) co-signaling receptors are differentially expressed in tissues; 2) heart, trachea, kidney, mammary gland and muscle express co-signaling receptors that mediate CD4+T cell functions such as priming, differentiation, effector, and memory; 3) urinary tumor, germ cell tumor, leukemia and chondrosarcoma express high levels of co-signaling receptors for T cell activation; 4) expression of inflammasome components are correlated with the expression of co-signaling receptors; 5) CD40, SLAM, CD80 are differentially expressed in leukocytes from patients with trauma, bacterial infections, polarized macrophages and in activated endothelial cells; 6) forward and reverse signaling of 50% co-inhibition receptors are upregulated in endothelial cells during inflammation; and 7) STAT1 deficiency in T cells upregulates MHC class II and co-stimulation receptors. Our results have provided novel insights into co-signaling receptors as physiological regulators and potentiate identification of new therapeutic targets for the treatment of sterile inflammatory disorders.
Assuntos
Tolerância Imunológica/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Receptores de Antígenos Quiméricos/imunologia , Linfócitos T/imunologia , Animais , Células Apresentadoras de Antígenos/imunologia , Células Apresentadoras de Antígenos/metabolismo , Antígeno B7-1/genética , Antígeno B7-1/imunologia , Antígenos CD40/genética , Antígenos CD40/imunologia , Diferenciação Celular/genética , Expressão Gênica/imunologia , Perfilação da Expressão Gênica , Humanos , Tolerância Imunológica/genética , Ativação Linfocitária/genética , Ativação Linfocitária/imunologia , Macrófagos/imunologia , Macrófagos/metabolismo , Camundongos , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos Quiméricos/genética , Transdução de Sinais/genética , Linfócitos T/metabolismoRESUMO
The tumor microenvironment is complex with the cancer stem cell (CSC) as a member within its community. This population possesses the capacity to self-renew and to cause cellular heterogeneity of the tumor. CSCs are resistant to conventional anti-proliferative drugs. In order to be curative, it is imperative that CSCs must be eliminated by cancer therapy. A variety of dietary phytochemicals and repositioned drugs can act synergistically with conventional anti-cancer agents. In this review, we advocate the development of a novel approach, namely combination therapy by incorporating both phytochemicals and repositioned drugs to target CSCs. We cover select dietary phytochemicals (curcumin, resveratrol, EGCG, genistein) and repurposed drugs (metformin, niclosamide, thioridazine, chloroquine). Five of the eight (curcumin, resveratrol, EGCG, genistein, metformin) are listed in "The Halifax Project", that explores "the concept of a low-toxicity 'broad-spectrum' therapeutic approach that could simultaneously target many key pathways and mechanisms" [1]. For these compounds, we discuss their mechanisms of action, in which models their anti-CSC activities were identified, as well as advantages, challenges and potentials of combination therapy.
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Antineoplásicos/farmacologia , Neoplasias/tratamento farmacológico , Células-Tronco Neoplásicas/efeitos dos fármacos , Compostos Fitoquímicos/farmacologia , Antineoplásicos/química , Antineoplásicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Suplementos Nutricionais , Reposicionamento de Medicamentos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Sinergismo Farmacológico , Humanos , Compostos Fitoquímicos/química , Compostos Fitoquímicos/uso terapêutico , Microambiente Tumoral/efeitos dos fármacosAssuntos
Falso Aneurisma/diagnóstico por imagem , Paralisia/etiologia , Artérias da Tíbia/diagnóstico por imagem , Neuropatia Tibial/etiologia , Adolescente , Falso Aneurisma/complicações , Fíbula/diagnóstico por imagem , Fíbula/lesões , Humanos , Imageamento por Ressonância Magnética , Masculino , Paralisia/diagnóstico , Fraturas da Tíbia/complicações , Fraturas da Tíbia/diagnóstico por imagem , Neuropatia Tibial/diagnósticoRESUMO
Globally, a body of comparative case-control studies suggests that rheumatoid arthritis (RA) patients are more prone to developing hearing loss (HL). However, experimental evidence that supports this hypothesis is still lacking because the human auditory organ is not readily accessible. The aim of this study was to determine the association between bone damage to the ossicles of the middle ear and HL, using a widely accepted murine model of collagen-induced arthritis (RA mice). Diarthrodial joints in the middle ear were examined with microcomputer tomography (microCT), and hearing function was assessed by auditory brainstem response (ABR). RA mice exhibited significantly decreased hearing sensitivity compared to age-matched controls. Additionally, a significant narrowing of the incudostapedial joint space and an increase in the porosity of the stapes were observed. The absolute latencies of all ABR waves were prolonged, but mean interpeak latencies were not statistically different. The observed bone defects in the middle ear that were accompanied by changes in ABR responses were consistent with conductive HL. This combination suggests that conductive impairment is at least part of the etiology of RA-induced HL in a murine model. Whether the inner ear sustains bone erosion or other pathology, and whether the cochlear nerve sustains pathology await subsequent studies. Considering the fact that certain anti-inflammatories are ototoxic in high doses, monitoring RA patients' auditory function is advisable as part of the effort to ensure their well-being.
Assuntos
Artrite Experimental/patologia , Artrite Reumatoide/patologia , Colágeno/toxicidade , Ossículos da Orelha/patologia , Perda Auditiva/patologia , Animais , Artrite Reumatoide/complicações , Audição , Perda Auditiva/complicações , Camundongos , Camundongos Endogâmicos DBA , Limiar Sensorial , Microtomografia por Raio-XRESUMO
INTRODUCTION: Development of non-invasive molecular imaging techniques that are based on cellular changes in inflammation has been of active interest for arthritis diagnosis. This technology will allow real-time detection of tissue damage and facilitate earlier treatment of the disease, thus representing an improvement over X-rays, which detect bone damage at the advanced stage. Tracing apoptosis, an event occurring in inflammation, has been a strategy used. PSVue 794 is a low-molecular-weight, near-infrared (NIR)-emitting complex of bis(zinc2+-dipicolylamine) (Zn-DPA) that binds to phosphatidylserine (PS), a plasma membrane anionic phospholipid that becomes flipped externally upon cell death by apoptosis. In this study, we evaluated the capacity of PSVue 794 to act as an in vivo probe for non-invasive molecular imaging assessment of rheumatoid arthritis (RA) via metabolic function in murine collagen-induced arthritis, a widely adopted animal model for RA. METHODS: Male DBA/1 strain mice were treated twice with chicken collagen type II in Freund's adjuvant. Their arthritis development was determined by measuring footpad thickness and confirmed with X-ray analysis and histology. In vivo imaging was performed with the NIR dye and the LI-COR Odyssey Image System. The level of emission was compared among mice with different disease severity, non-arthritic mice and arthritic mice injected with a control dye without the Zn-DPA targeting moiety. RESULTS: Fluorescent emission correlated reliably with the degree of footpad swelling and the manifestation of arthritis. Ex vivo examination showed emission was from the joint. Specificity of binding was confirmed by the lack of emission when arthritic mice were given the control dye. Furthermore, the PS-binding protein annexin V displaced the NIR dye from binding, and the difference in emission was numerically measurable on a scale. CONCLUSIONS: This report introduces an economical alternative method for assessing arthritis non-invasively in murine models. Inflammation in feet and ankles can be measured longitudinally using the PSVue 794 probe for cell death and with a commonly available multipurpose imager. This technique provides metabolic and functional information that anatomical measurement of footpad swelling or visual determination of arthritic index cannot. It also may decrease the number of animals required per experiment because tissue damage will not necessarily require evaluation by harvesting joints for histology.
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Artrite Experimental/diagnóstico , Carboxiliases , Diagnóstico por Imagem/métodos , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Animais , Artrite Experimental/induzido quimicamente , Colágeno Tipo II/toxicidade , Masculino , Camundongos , Camundongos Endogâmicos DBARESUMO
Infection is the outcome of a contest between a pathogen and its host. In the disease leishmaniasis, the causative protozoan parasites are harbored inside the macrophages. Leishmania species adapt strategies to make the infection chronic, keeping a balance between their own and the host's defense so as to establish an environment that is favorable for survival and propagation. Activation of peroxisome proliferator-activated receptor (PPAR) is one of the tactics used. This ligand-activated nuclear factor curbs inflammation to protect the host from excessive injuries by setting a limit to its destructive force. In this paper, we report the interaction of host PPARs and the pathogen for visceral leishmaniasis, Leishmania donovani, in vivo and in vitro. PPAR expression is induced by parasitic infection. Leishmanial activation of PPARγ promotes survival, whereas blockade of PPARγ facilitates removal of the parasite. Thus, Leishmania parasites harness PPARγ to increase infectivity.
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Acute inflammation follows defined phases of induction, inflammation and resolution, and resolution occurs by an active process that requires cyclooxygenase-2 (COX-2) activity. This study aims to address whether this paradigm extends to recognized model of chronic inflammation. We demonstrated that murine collagen-induced arthritis follows a similar sequential course. Interestingly, COX-2 and its metabolite, the presumably proinflammatory PGE(2), are present in the joints during resolution, and blocking COX-2 activity and PGE(2) production within this period perpetuated, instead of attenuated, inflammation. Repletion with PGE(2) analogs restored homeostasis, and this function is mediated by the proresolving lipoxygenase metabolite, lipoxin A(4), a potent stop signal. Thus, the study provided in vivo evidence for a natural, endogenous link between the cyclooxygenase-lipoxygenase pathways and showed that PGE(2) serves as a feedback inhibitor essential for limiting chronic inflammation in autoimmune arthritis. These findings may explain the enigma regarding why COX-2 inhibitors are palliative rather than curative in humans, because blocking resolution may mitigate the benefit of preventing induction.
Assuntos
Artrite Experimental/metabolismo , Artrite Experimental/fisiopatologia , Ciclo-Oxigenase 2/metabolismo , Dinoprostona/metabolismo , Mediadores da Inflamação/farmacologia , Lipoxinas/biossíntese , Animais , Artrite Experimental/imunologia , Artrite Reumatoide/imunologia , Artrite Reumatoide/metabolismo , Artrite Reumatoide/fisiopatologia , Inibidores de Ciclo-Oxigenase/farmacologia , Inflamação/imunologia , Inflamação/metabolismo , Inflamação/fisiopatologia , Lipoxinas/fisiologia , Masculino , Camundongos , Nitrobenzenos/farmacologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sulfonamidas/farmacologiaRESUMO
Parasitic infections induce a magnitude of host responses. At the opposite ends of the spectrum are those that ensure the host's needs to eliminate the invaders and to minimize damage to its own tissues. This review analyzes how parasites would manipulate immunity by activating the immunosuppressive nuclear factor, peroxisome proliferator-activated receptors (PPARs) with type 2 cytokines and free fatty acids from arachidonic acid metabolism. PPARs limit the action of type 1 immunity, in which classically activated macrophages act through the production of proinflammatory signals, to spare the parasites. They also favor the development of alternately activated macrophages which control inflammation so the host would not be destroyed. Possibly, the nuclear factors hold a pivotal role in the establishment of chronic infection by delicately balancing the pro- and anti-inflammatory signaling mechanisms and their ligands may be used as combination therapeutics to limit host pathology.
Assuntos
Evasão da Resposta Imune/imunologia , Doenças Parasitárias/metabolismo , Receptores Ativados por Proliferador de Peroxissomo/metabolismo , Animais , Humanos , Imunidade , Ligantes , Doenças Parasitárias/imunologiaRESUMO
The phytochemical curcumin, from the Indian spice turmeric, has many biological properties, including anti-inflammatory and anti-carcinogenic activities. We have examined the effects of curcumin on the rat C6 glioma cell line. Treated and control cells were analyzed by Hoechst 33342 dye and flow cytometry. We observed a decrease in the side population (SP) of C6 cells after daily curcumin treatment of the C6 cells. Direct incubation of curcumin to C6 cells during the Hoechst assay also decreased SP. Since SP has been associated with stem cell populations, curcumin may be a dietary phytochemical with potential to target cancer stem cells.
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Antineoplásicos Fitogênicos/farmacologia , Curcumina/farmacologia , Glioma/tratamento farmacológico , Células-Tronco Neoplásicas/efeitos dos fármacos , Animais , Benzimidazóis/farmacocinética , Diferenciação Celular/efeitos dos fármacos , Processos de Crescimento Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Citometria de Fluxo , Corantes Fluorescentes/farmacocinética , Glioma/metabolismo , Glioma/patologia , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Fenótipo , Ratos , Verapamil/farmacologiaRESUMO
Inflammation is considered the underlying cause of numerous disorders, and the practice of taking antiinflammatories as diet supplements has become increasingly prevalent. This study addresses the bioavailablity of a well-established dietary antiinflammatory, curcumin, and examines its effect on adaptive immunity. Visceral leishmaniasis is a major parasitic disease which protection relies on cell-mediated immunity and production of nitric oxide. We found that long-term, low-dose, oral consumption of curcumin activates peroxisome proliferator-activated receptor-gamma, deactivates type 1 response, inhibits inducible nitric oxide synthase, and interferes with adaptive immunity to exacerbate the pathogenesis of Leishmania donovani infection in vivo. These in vivo effects can be correlated to activities on infected residential macrophages in vitro. Therefore, when reactive radicals generated from inflammation play the dominant role in elimination of pathogens, excessive use of the antioxidative supplements may compromise microbial defense. Nonetheless, it should be noted with equal importance that our finding, conversely, also strengthens the prospect that curcumin may alleviate type 1 response disorders.
Assuntos
Anti-Inflamatórios/farmacologia , Curcumina/farmacologia , Modelos Animais de Doenças , Imunidade Celular/efeitos dos fármacos , Leishmaniose Visceral/patologia , Animais , Citocinas/metabolismo , Ensaio de Imunoadsorção Enzimática , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C3H , Óxido Nítrico Sintase Tipo II/antagonistas & inibidores , PPAR gama/agonistas , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
The green tea polyphenol epigallocatechin-3-gallate (EGCG) has cancer chemopreventive properties against various types of cancers. The compound is known to attack various targets in transformed cells. In this report, we examined the action of EGCG on ovarian cancer cells. Eight ovarian cancer cell lines were tested (SKOV3, CAOV3, OVCAR3, OVCAR10, A2780, CP70, C30, and C200) and showed IC50s for EGCG at the micromolar range, including ones that are resistant to the chemotherapeutic drug cisplatin. The ovarian cancer cells were sensitive to H2O2 at similar concentrations, and EGCG treatment led to enhanced intracellular H2O2. Neutralization with pyruvate, a scavenger of H2O2, suggests that the toxicity of EGCG may be mediated by oxidative stress from the free radical. Addition of Tempol, a superoxide dismutase mimetic, demonstrates that H2O2 might be generated endogenously from superoxide. The toxicity of cisplatin and the development of cisplatin resistance are major obstacles in treatment of ovarian cancer. We found that addition of EGCG amplified the toxicity of cisplatin. EGCG increased cisplatin potency by three to six-fold in SKOV3, CAOV3, and C200 cells, the latter being a cell line induced to have several hundred fold resistant to cisplatin above the parental line. Our findings suggest that EGCG may accentuate oxidative stress to inhibit growth of ovarian cancer cells and sensitize them to cisplatin.
Assuntos
Catequina/análogos & derivados , Proliferação de Células/efeitos dos fármacos , Cisplatino/farmacologia , Peróxido de Hidrogênio/metabolismo , Antineoplásicos/farmacologia , Antioxidantes/farmacologia , Catequina/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Óxidos N-Cíclicos/farmacologia , Relação Dose-Resposta a Droga , Resistencia a Medicamentos Antineoplásicos , Sinergismo Farmacológico , Feminino , Fluoresceínas/química , Fluoresceínas/metabolismo , Humanos , Peróxido de Hidrogênio/farmacologia , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/metabolismo , Neoplasias Ovarianas/patologia , Ácido Pirúvico/farmacologia , Marcadores de SpinRESUMO
Upon Leishmania infection, macrophages are activated to produce nitrogen and oxygen radicals simultaneously. It is well established that the infected host cells rely on nitric oxide (NO) as the major weapon against the intracellular parasite. In India where leishmaniasis is endemic, the spice turmeric is used prolifically in food and for insect bites. Curcumin, the active principle of turmeric, is a scavenger of NO. This report shows that curcumin protects promastigotes and amastigotes of the visceral species, Leishmania donovani, and promastigotes of the cutaneous species, L. major, against the actions of S-nitroso-N-acetyl-D,L-penicillamine (SNAP) and DETANONOate, which release NO, 3-morpholino-sydnonimine hydrochloride (SIN-1), which releases NO and superoxide, and peroxynitrite, which is formed from the reaction of NO with superoxide. Thus, curcumin, as an antioxidant, is capable of blocking the action of both NO and NO congeners on the Leishmania parasite.
Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Curcumina/farmacologia , Leishmania donovani/efeitos dos fármacos , Leishmania major/efeitos dos fármacos , Molsidomina/análogos & derivados , Doadores de Óxido Nítrico/farmacologia , Óxido Nítrico/metabolismo , Penicilamina/análogos & derivados , Animais , Leishmania donovani/crescimento & desenvolvimento , Leishmania major/crescimento & desenvolvimento , Camundongos , Camundongos Endogâmicos BALB C , Molsidomina/farmacologia , Óxido Nítrico/farmacologia , Compostos Nitrosos/farmacologia , Penicilamina/farmacologia , Ácido Peroxinitroso/farmacologiaRESUMO
Convenient and economical assays capable of screening many compounds are vital to advance the development of drug therapy. This is particularly important for many of the infections that occur mainly in the Third World. The development of such a spectrofluorometric assay for the protozoan parasite Leishmania is presented here. Using multimeric (four monomers) green fluorescent protein (GFP), Leishmania amazonensis promastigotes were generated with brightness measurable in 96-well microtiter plates. The promastigotes maintained the parental characteristics, were infective to murine macrophages and to mice, and the level of GFP fluorescence corresponded to the number of inoculated cells. The feasibility of using this assay for testing drugs kinetically and in a concentration-dependent manner, under microplate culture condition, was demonstrated with amphotericin B and the herbicide oryzalin, respectively. This assay is the first to allow a real-time analysis of antileishmanial agents with live promastigotes. The method of expressing multimeric GFP for in vitro drug screening is likely to be extendable to many species of parasitic protozoa.
Assuntos
Leishmania/efeitos dos fármacos , Proteínas Luminescentes/genética , Testes de Sensibilidade Parasitária/métodos , Espectrometria de Fluorescência/métodos , Sulfanilamidas , Anfotericina B/farmacologia , Animais , Dinitrobenzenos/farmacologia , Citometria de Fluxo/métodos , Expressão Gênica , Proteínas de Fluorescência Verde , Leishmania/genética , Leishmania/crescimento & desenvolvimento , Estágios do Ciclo de Vida , Proteínas Luminescentes/biossíntese , Camundongos , Camundongos Endogâmicos BALB C , TransfecçãoRESUMO
The polyphenolic compounds curcumin and quercetin increased sensitivity of ovarian cancer cells (CAOV3 and SKOV3) to cisplatin. The effect was obtained when the compounds were added simultaneously with cisplatin, as well as when they were added 24 h before. High serum levels of certain cytokines, for example interleukin-6 (IL-6), have been associated with poor prognosis and cisplatin resistance in various forms of cancer. Furthermore, it has been hypothesized that cytokines may increase proliferation, metastasis, and stimulate production of detoxification enzymes and multi-drug resistant proteins. Curcumin inhibits the production of many cytokines. The two ovarian cell lines differ significantly in IL-6 production, and correspondingly the high producer, CAOV3, was less susceptible to cisplatin. Curcumin inhibited the production of IL-6 in this cell suggesting that one of the mechanisms for synergy between cisplatin and curcumin was by reducing the autologous production of IL-6. However, the synergy was also observed in the low IL-6 producer, SKOV3, indicating that the action was most probably a result of multiple targeting. In sum, this study suggests that the compounds, curcumin and quercetin, potentially may be useful for enhancing drug sensitivity in certain cancer.