RESUMO
The leishmaniases are a group of diseases caused by the protozoan parasite belonging to the genus Leishmania. In the New World, although dogs are considered the main parasite reservoir, in the last two decades, several studies have confirmed the role of cats (Felis catus) in the epidemiology of the disease and feline leishmaniasis (FeL) is now considered to be an emerging disease. The present review summarizes the current knowledge about FeL, focusing on important immunopathological aspects, epidemiology, and diagnostic methods applied for felines in Brazil. Cats are infected with the same species of Leishmania found in dogs (i.e., Leishmania infantum). Like dogs, skin lesions are the most common in cats with clinical FeL, mainly affecting the cephalic region and less frequently the legs which may be accompanied by generalized signs or visceral involvement. Information on the immune response of cats to Leishmania infection is scarce; however, efficient infection control is seen in most cases. For diagnosis, generally, the same methods as those in dogs are used, mainly serological tools. But there is a lack of studies focusing the performance of these methods for diagnosing FeL. The estimated overall prevalence of FeL in Brazil is 8%, with L. infantum being the most prevalent species. However, infections with Leishmania braziliensis and Leishmania amazonensis have also been reported. In conclusion, although there has been an increase in the publication related to FeL in Brazil in recent years, there is a lack of research relating immune response and diagnosis of these animals. Cats have been shown to be competent hosts for Leishmania parasites, and their role in the epidemiology of the disease cannot be underestimated, especially in areas of Brazil where the disease is historically endemic.
Assuntos
Doenças do Gato , Doenças do Cão , Leishmania infantum , Leishmaniose Visceral , Leishmaniose , Animais , Brasil , Gatos , CãesRESUMO
In order to find new alternatives for vector control and personal protection, we evaluated the larvicidal and repellent activity of essentials oils from plants found in the Northeast of Brazil against Aedes aegypti Linnaeus mosquitoes. The plants tested include Xylopia laevigata, Xylopia frutescens, and Lippia pedunculosa and their major compounds, piperitenone oxide, and (R)-limonene. The essential oil of L. pedunculosa and its major volatile compounds were shown to be toxic for Ae. aegypti larvae with a LC50 lower than 60 ppm. The essential oil of plants from the Xylopia genus, on the other hand, showed no activity against Ae. aegypti, proving to be toxic to mosquito larvae only when concentrations were higher than 1000 ppm. All plants tested provided some degree of protection against mosquitoes landing, but only the essential oil of L. pedunculosa and the volatile compound piperitenone oxide suppressed 100% of mosquitoes landing on human skin, in concentrations lower than 1%. Among the plants studied, the essential oil of L. pedunculosa and its volatiles compounds have shown the potential for the development of safe alternative for mosquito larvae control and protection against Ae. aegypti mosquito bites.
Assuntos
Aedes , Inseticidas/toxicidade , Óleos Voláteis/toxicidade , Animais , Brasil , Humanos , Larva , Lippia , Controle de Mosquitos , XylopiaRESUMO
Leishmania spp are the causative agents of a spectrum of diseases termed leishmaniasis that affect mammals, including humans and dogs. Although reactive nitrogen species are employed in the control of parasitism by the immune system, it is known that Leishmania can withstand this oxidative stress. As the mechanism by which these species are resistant to nitric oxide (NO) is poorly understood, the main objective of this study was to evaluate the expression of glyceraldehyde 3-phosphate dehydrogenase (GAPDH) in Leishmania amazonensis and Leishmania chagasi promastigotes showing natural resistance to NO. GAPDH transcript levels were quantified by real-time polymerase chain reaction amplification, and GAPDH activity (assessed by levels of NADH oxidation) was measured by spectrophotometry. The level of nitration in total protein was assessed by immunoblotting. The results demonstrated an increase in GAPDH expression in resistant isolates of both species compared to susceptible isolates. The increase in GAPDH expression led to an increase in the activity of GAPDH in L. amazonensis human isolates resistant to NO. The pattern of protein nitration did not differ between sensitive and resistant isolates. Our results suggest that changes in expression of GAPDH may be responsible, at least in part, to natural resistance to NO found in human and canine Leishmania spp.
Assuntos
Expressão Gênica/efeitos dos fármacos , Gliceraldeído 3-Fosfato Desidrogenase (NADP+)/genética , Leishmania infantum/genética , Leishmania/genética , Estágios do Ciclo de Vida/efeitos dos fármacos , Óxido Nítrico/farmacologia , Proteínas de Protozoários/genética , Meios de Cultura , Resistência a Medicamentos , Gliceraldeído 3-Fosfato Desidrogenase (NADP+)/metabolismo , Leishmania/efeitos dos fármacos , Leishmania/enzimologia , Leishmania/crescimento & desenvolvimento , Leishmania infantum/efeitos dos fármacos , Leishmania infantum/enzimologia , Leishmania infantum/crescimento & desenvolvimento , NAD/metabolismo , Óxido Nítrico/metabolismo , Oxirredução , Proteínas de Protozoários/metabolismo , Nitrito de Sódio/química , Nitrito de Sódio/farmacologiaRESUMO
No new publication appeared in the past year on early stage ovarian cancer. The current GOG study will help determine the relative benefits and toxicities of intraperitoneal P32 versus cyclophosphamide and cisplatin in this group of patients. Recent studies in advanced ovarian carcinoma suggest a modest additional benefit for multidrug regimens, but cisplatin and cyclophosphamide remains an acceptable first line treatment for stage III and IV disease. Additional information on the use of carboplatin in advanced disease has been published, and this agent is now accepted as part of standard first line treatment programs. Platinum-based chemotherapy continues to be the mainstay of treatment for recurrent disease. With the commercial availability of taxol, a new salvage treatment is now available. Taxol will be increasingly studied as a part of front-line therapy as well as its role in the salvage setting. Altretamine and ifosfamide appear to have activity even in some patients with platinum-resistant disease, but these drugs will not likely have a major impact on ovarian cancer treatment. The use of high-dose chemotherapy with autologous bone marrow or peripheral stem cell support offers an exciting and potentially beneficial approach for patients with poor prognosis disease. The use of intraperitoneal chemotherapy and biologic agents continues to be problematic, and additional improvements are needed before they are considered useful outside of a research setting. With the exception of P32 for early stage disease, radiation therapy is likely to continue to play a minor role in the treatment of ovarian cancer. Few studies involving non-epithelial ovarian carcinomas were published during the past year. A definitive report was published demonstrating the activity of cisplatin-based chemotherapy (BEP) in patients with advanced dysgerminoma. Chemotherapy which preserves fertility provides an effective alternative to irradiation. Cisplatin-based chemotherapy was active in mixed mullerian tumors of the ovary although the prognosis of these patients was worse than patients with epithelial ovarian cancer. Concurrent chemotherapy added to irradiation has not improved survival over radiotherapy alone in patients with cancer of the uterine cervix. Patients still failed locally and distantly. Extended field irradiation to involved paraaortic lymph nodes with weekly cisplatin generated promising pilot data. Randomized trials evaluating the use of neoadjuvant chemotherapy prior to pelvic radiotherapy showed no benefit and increased toxicity. Ifosfamide alone or in combination regimens is an active drug but with serious side effects which require careful monitoring.(ABSTRACT TRUNCATED AT 400 WORDS)
Assuntos
Neoplasias dos Genitais Femininos/terapia , Terapia Combinada , Neoplasias do Endométrio/terapia , Feminino , Neoplasias dos Genitais Femininos/patologia , Humanos , Estadiamento de Neoplasias , Neoplasias Ovarianas/terapia , Ensaios Clínicos Controlados Aleatórios como Assunto , Neoplasias do Colo do Útero/terapiaRESUMO
With improved screening and education, a greater proportion of breast cancer is detected at an early stage. Although the prognosis for many of these patients is excellent following definitive local therapy alone, some subsets of node-negative patients have a 30% chance of eventually developing metastatic disease that will be incurable with current therapy. Thus, an increasing proportion of early-stage patients are being offered some form of adjuvant therapy, with the expectation of improved relapse-free survival, and possibly improved overall survival. Efforts have been made to base the selection of patients for adjuvant therapy on specific prognostic factors. Meanwhile, the scope and complexity of putative prognostic factors continues to widen, and now includes such items as the presence of occult microscopic metastases, DNA ploidy and proliferative fraction, cytogenetic abnormalities, oncogene expression, growth factor receptors, and expression of hormonally regulated proteins. In addition, there is now a considerable range of options with regard to the composition, dose intensity, and sequence of multimodality therapy. Data regarding the classification, significance, and interpretation of prognostic factors is reviewed together with the development, current status, and recommendations regarding adjuvant therapy for patients with early-stage breast cancer. For 1991, the National Cancer Institute (NCI) has estimated that 175,000 new cases of breast cancer will be diagnosed in American women. It is also estimated that 44,500 women will die of breast cancer. Unfortunately, the age-adjusted death rate from breast cancer has shown no overall change from 1930 through 1987. However, effective screening techniques continue to identify an increasing percentage of early-stage tumors, which should exceed 50% of all new tumors in 1991. Ultimately, our understanding of environmental and genetic risk factors may identify new ways to reduce the impact of this disease. In the interim, development and application of effective systemic adjuvant chemotherapy and hormonal therapy has become increasingly important. There is no question that a greater proportion of patients with less extensive disease are now being offered some form of adjuvant therapy. Meanwhile, selection of patients for adjuvant therapy, and choice among specific adjuvant regimens, has remained controversial. Analysis of multiple prognostic factors is performed not only in the context of cooperative investigational trials, but more often in the offices of individual physicians caring for individual patients. Tumor biopsies can now be routinely sent to specialized laboratories for performance of complex assays with potential prognostic information, although interpretation of these results with reference to a specific patient is often uncertain.(ABSTRACT TRUNCATED AT 400 WORDS)