RESUMO
The rat lungworm Angiostrongylus cantonensis is a zoonotic parasite and the main cause of eosinophilic meningitis in the world. Its main source of nutrients originates from the degradation of host hemoglobin in blood-feeding helminths, such as A. cantonensis. The purpose of this study was to analyze the ultrastructure of the intestinal cells by using of transmission electron microscopy (TEM). A. cantonensis worms obtained from Rattus norvegicus (norway rats) from endemic area were used for TEM. The ultrastructural analysis was performed using fragments cut from the middle part of the worms, and the TEM study revealed the cells with microvilli and nuclei containing areas of loose and condensed chromatin and the presence of macrovesicles and microvesicles of digestion and it was observed in this study that intestinal epithelium is look like a syncytium. The ultrastructural aspects of the intestinal cells surface of A. Cantonensis the indicate that the intestinal epithelium is a multinucleate mosaic or syncytium.
RESUMO
Healthcare-associated infections cause significant patient morbidity and mortality, and contribute to growing healthcare costs, whose effects may be felt most strongly in developing countries. Active surveillance systems, hospital staff compliance, including hand hygiene, and a rational use of antimicrobials are among the important measures to mitigate the spread of healthcare-associated infection within and between hospitals. Klebsiella pneumoniae is an important human pathogen that can spread in hospital settings, with some forms exhibiting drug resistance, including resistance to the carbapenem class of antibiotics, the drugs of last resort for such infections. Focusing on the role of patient movement within and between hospitals on the transmission and incidence of enterobacteria producing the K. pneumoniae Carbapenemase (KPC, an enzyme that inactivates several antimicrobials), we developed a metapopulation model where the connections among hospitals are made using a theoretical hospital network based on Brazilian hospital sizes and locations. The pathogen reproductive number, R0 that measures the average number of new infections caused by a single infectious individual, was calculated in different scenarios defined by both the links between hospital environments (regular wards and intensive care units) and between different hospitals (patient transfer). Numerical simulation was used to illustrate the infection dynamics in this set of scenarios. The sensitivity of R0 to model input parameters, such as hospital connectivity and patient-hospital staff contact rates was also established, highlighting the differential importance of factors amenable to change on pathogen transmission and control.
Assuntos
Infecção Hospitalar/epidemiologia , Resistência a Múltiplos Medicamentos , Hospitais/estatística & dados numéricos , Transferência de Pacientes/estatística & dados numéricos , Brasil/epidemiologia , Humanos , Unidades de Terapia Intensiva , Testes de Sensibilidade Microbiana , PrevalênciaRESUMO
In response to pathogens, the higher vertebrate innate immune system activates pro-inflammatory caspase-1 which is responsible for the processing and secretion of several important cytokines involved in the host's defence against infection. To date, caspase-1 has been described in few teleost fish, and its activity has been demonstrated through substrate cleavage and inhibition by pharmacological agents. In this study, the detection of the active form of caspase-1 during the immune response in salmonid fish is described, where two antibodies were produced. These antibodies differentially recognize the structural epitopes of the inactive pro-caspase-1 and the processed active form of the caspase. Firstly, caspase-1 activation was demonstrated in vitro by ELISA, Western blotting and immunocytochemistry in rainbow trout macrophages exposed to different pathogen-associated molecular patterns plus the pathogen Aeromonas hydrophila. This activity was clearly abrogated by a caspase inhibitor and seems to be unrelated to IL-1ß secretion. Caspase-1 activation was then validated in vivo in gill cells from fish challenged with Aeromonas salmonicida. These results represent the first demonstration of caspase-1 activation in salmonids, and the first evidence of the putative regulatory role which this protease plays in inflammatory response in this fish group, as described for some other teleosts and mammals.
Assuntos
Caspase 1/metabolismo , Doenças dos Peixes/imunologia , Infecções por Bactérias Gram-Negativas/veterinária , Macrófagos/efeitos dos fármacos , Oncorhynchus mykiss/imunologia , Moléculas com Motivos Associados a Patógenos/farmacologia , Aeromonas hydrophila/imunologia , Animais , Ativação Enzimática/efeitos dos fármacos , Ativação Enzimática/imunologia , Doenças dos Peixes/enzimologia , Brânquias/efeitos dos fármacos , Brânquias/enzimologia , Infecções por Bactérias Gram-Negativas/enzimologia , Infecções por Bactérias Gram-Negativas/imunologia , Macrófagos/enzimologia , Macrófagos/imunologia , Macrófagos/microbiologia , Oncorhynchus mykiss/microbiologiaRESUMO
La enfermedad de Paget mamaria es una patología poco común en la mama, sin embargo, tiene gran importancia por su alta asociación a carcinoma mamario y porque requiere de un alto índice de sospecha. Se presenta el caso de una mujer de 56 años con enfermedad de Paget mamaria con focos microscópicos de invasión y compromiso linfonodal masivo. Se realiza una revisión de esta patología, con especial énfasis en la sospecha, diagnóstico, manejo, estadificación, tratamiento y pronóstico desde el punto de vista médico y quirúrgico.
Assuntos
Humanos , Feminino , Pessoa de Meia-Idade , Carcinoma Ductal de Mama/cirurgia , Carcinoma Ductal de Mama/patologia , Doença de Paget Mamária/cirurgia , Doença de Paget Mamária/patologia , Neoplasias da Mama/cirurgia , Neoplasias da Mama/patologia , Carcinoma in Situ , Doença de Paget Mamária/diagnóstico , Doença de Paget Mamária/etiologia , Excisão de Linfonodo , Mastectomia , Estadiamento de Neoplasias , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/etiologia , Prognóstico , Mamilos/patologiaRESUMO
La Gangrena de Fournier es una enfermedad infecciosa caracterizada por una fascitis necrotizante de evolución fulminante que afecta a la región perineal, genital o perianal, presentando una rápida progresión y alta letalidad, siendo la etiología identificable en un 95 por ciento de los casos. La enfermedad ha sido descrita en ambos géneros, con edad promedio de presentación de 40 años y una mayor prevalencia en hombres, con una relación 10:1. La variedad de manifestaciones clínicas dificulta el diagnóstico, el que es fundamentalmente clínico. El tratamiento debe ser oportuno y agresivo, contemplando tres pilares fundamentales: manejo hidroelectrolítico y nutricional, antiobioterapia de amplio espectro y desbridamiento quirúrgico amplio. En este artículo presentamos una revisión sistemática actualizada de la literatura acerca de esta interesante entidad patológica, con especial énfasis en la epidemiología, etiología, presentación clínica, diagnóstico y tratamiento.
Assuntos
Humanos , Gangrena de Fournier/diagnóstico , Gangrena de Fournier/terapia , Fasciite Necrosante , Gangrena de Fournier/etiologia , PrognósticoRESUMO
El cáncer de piel no melanoma es la neoplasia más frecuente en el ser humano, sin embargo su incidencia es aún mayor en individuos trasplantados usuarios de inmunosupresión prolongada, representado en ellos el 95 por ciento de los cánceres de piel, con un comportamiento más agresivo y mayor probabilidad de recidiva. A diferencia de la población general, en la cual el cáncer basocelular es el más común, en estos pacientes el carcinoma de células escamosas es el más habitual. El papel del tratamiento inmunosupresor en la génesis del cáncer de piel no melanoma es vastamente reconocido. Los cánceres de piel resultan tanto de una disminución de la actividad inmunológica, como de los efectos oncogénicos directos vinculados a algunos inmunosupresores. La carga tumoral específica parece estar vinculada con el tipo, dosis y duración de la inmunosupresión. En este artículo presentamos una revisión sistemática actualizada de la literatura acerca de esta interesante entidad patológica, con especial énfasis en la epidemiología, factores de riesgo, patogénesis y terapia.
Assuntos
Humanos , Terapia de Imunossupressão/efeitos adversos , Neoplasias Cutâneas/etiologia , Neoplasias Cutâneas/terapia , Transplante de Órgãos/efeitos adversos , Carcinoma Basocelular , Carcinoma de Células Escamosas , Neoplasias Cutâneas/epidemiologia , Fatores de RiscoRESUMO
Los pólipos son una de las afecciones más comunes que afectan al colon y recto y se encuentran en una proporción importante entre la población adulta. Aunque la mayoría de los pólipos son benignos, se halla bien fundada la idea de que existe una relación entre ciertos pólipos y el cáncer, es por ese motivo que surge como objetivo general, determinar la incidencia de pólipos colorectales diagnosticados endoscopicamente y sus resultados de anatomía patológica de los pacientes atendidos en el Instituto Gastroenterológico Boliviano Japonés, durante el periodo de tiempo abarcado entre el 15 de julio 2006 y 15 de julio 2008. Este estudio es de tipo descriptivo transversal, con una muestra de 1 19 pacientes diagnosticados y registrados con pólipos intestinales en el lugar y período de tiempo anteriormente mencionados; del cual obtuvimos los siguientes resultados: 73 pacientes (61%) correspondieron al sexo femenino, el intervalo de edad más afectado fue 45-65 años con 41 pacientes (34%), 55 pacientes ( 46%) presentaron pólipos en recto, 95 pacientes (80%) presentaron un solo pólipo; la colonoscopia fue el método diagnóstico de mayor uso en 80 pacientes (67%), 54 pacientes (45%) de los casos presentaron pólipos Yamada I; la polipectomía endoscópica fue la conducta realizada en 92 pacientes (77%), 77 pacientes (65%) resultaron con pólipos adenomatosos, y de estos 62 pacientes (81%) fueron adenomatosos tubulares, 42 pacientes (35%) presentaron displasia, 68 pacientes (57%) de los anteriores correspondieron a displasia leve; y 1 paciente (1%) de los casos fueron diagnosticados con adenocarcinoma.
Polyps are one of the most common conditions affecting the colon and rectum and are found in a significant proportion of the adult population.Although most polyps are benign, is well-founded the idea that exists a relationship between sme polyps and cancer, that's why our general objective is to determine the incidence of endoscopically diagnosed colorectal polyps and anatomical results pathology of patients treated in Bolivian Japanesse Gastroenterological Institute during the period comprised between 15 July 2006 and 15 July 2008. This study is a descriptive, cross-sectional, using a sample of 119 patients diagnosed and registered with intestinal polyps in the place and time mentioned above, which we obtained the following results: 73 patients (61%) were females, the interval of most affected age was 45-65 years with 41 patients (34%), 55 patients (46%) had polyps in the rectum, 95 patients (80%) of patients had one polyp, colonoscopy was the most widely used diagnostic method in 80 patients (67%), 54 patients (45%) cases Yamada I polyps, endoscopic polypectomy was the conduct performed in 92 patients (77%), 77 patients (65%) were adenomatous polyps, and these 62 patients (81 %) were adenomatous tubular, 42 patients (35%) had dysplasia, 68 patients (57%) of the above are small dysplasia and 1 patient (1 %) cases were diagnosed with cancer.
RESUMO
Chagas disease is a major public health problem in Bolivia. In the city of Cochabamba, 58% of the population lives in peripheral urban districts ("popular zones") where the infection prevalence is extremely high. From 1995 to 1999, we studied the demographics of Chagas infections in children from five to 13 years old (n = 2218) from the South zone (SZ) and North zone (NZ) districts, which differ in social, environmental, and agricultural conditions. Information gathered from these districts demonstrates qualitative and quantitative evidence for the active transmission of Trypanosoma cruzi in urban Cochabamba. Seropositivity was high in both zones (25% in SZ and 19% in NZ). We observed a high risk of infection in children from five to nine years old in SZ, but in NZ, a higher risk occurred in children aged 10-13, with odds ratio for infection three times higher in NZ than in SZ. This difference was not due to triatomine density, since more than 1,000 Triatoma infestans were captured in both zones, but was possibly secondary to the vector infection rate (79% in SZ and 37% in NZ). Electrocardiogram abnormalities were found to be prevalent in children and pre-adolescents (SZ = 40%, NZ = 17%), indicating that under continuous exposure to infection and re-infection, a severe form of the disease may develop early in life. This work demonstrates that T. cruzi infection should also be considered an urban health problem and is not restricted to the rural areas and small villages of Bolivia.
Assuntos
Doença de Chagas/transmissão , Conhecimentos, Atitudes e Prática em Saúde , Insetos Vetores/parasitologia , Triatoma/parasitologia , Trypanosoma cruzi/isolamento & purificação , Adolescente , Animais , Bolívia/epidemiologia , Gatos , Bovinos , Doença de Chagas/diagnóstico , Doença de Chagas/epidemiologia , Criança , Pré-Escolar , Cães , Feminino , Humanos , Masculino , Densidade Demográfica , Prevalência , Coelhos , Fatores de Risco , Estudos Soroepidemiológicos , Ovinos , Fatores Socioeconômicos , População UrbanaRESUMO
Chagas disease is a major public health problem in Bolivia. In the city of Cochabamba, 58 percent of the population lives in peripheral urban districts ("popular zones") where the infection prevalence is extremely high. From 1995 to 1999, we studied the demographics of Chagas infections in children from five to 13 years old (n = 2218) from the South zone (SZ) and North zone (NZ) districts, which differ in social, environmental, and agricultural conditions. Information gathered from these districts demonstrates qualitative and quantitative evidence for the active transmission of Trypanosoma cruzi in urban Cochabamba. Seropositivity was high in both zones (25 percent in SZ and 19 percent in NZ). We observed a high risk of infection in children from five to nine years old in SZ, but in NZ, a higher risk occurred in children aged 10-13, with odds ratio for infection three times higher in NZ than in SZ. This difference was not due to triatomine density, since more than 1,000 Triatoma infestans were captured in both zones, but was possibly secondary to the vector infection rate (79 percent in SZ and 37 percent in NZ). Electrocardiogram abnormalities were found to be prevalent in children and pre-adolescents (SZ = 40 percent, NZ = 17 percent), indicating that under continuous exposure to infection and re-infection, a severe form of the disease may develop early in life. This work demonstrates that T. cruzi infection should also be considered an urban health problem and is not restricted to the rural areas and small villages of Bolivia.
Assuntos
Adolescente , Animais , Gatos , Bovinos , Criança , Pré-Escolar , Cães , Feminino , Humanos , Masculino , Coelhos , Doença de Chagas/transmissão , Conhecimentos, Atitudes e Prática em Saúde , Insetos Vetores/parasitologia , Triatoma/parasitologia , Trypanosoma cruzi/isolamento & purificação , Bolívia/epidemiologia , Doença de Chagas/diagnóstico , Doença de Chagas/epidemiologia , Densidade Demográfica , Prevalência , Fatores de Risco , Estudos Soroepidemiológicos , Ovinos , Fatores Socioeconômicos , População UrbanaRESUMO
Tuberculosis control is hampered by the widespread increase in multidrug resistance. Rapid drug susceptibility testing would greatly aid in the adequate treatment of the disease. This study evaluates the usefulness of the colorimetric method using Alamar Blue for the rapid detection of resistance to rifampicin and isoniazid in 63 clinical isolates of Mycobacterium tuberculosis in Peru. Results obtained by receiver operating characteristic curve analysis and measures of gain in certainty showed greater diagnostic accuracy than with the gold standard, the proportion method on Löwenstein-Jensen medium.
Assuntos
Mycobacterium tuberculosis/classificação , Kit de Reagentes para Diagnóstico , Tuberculose Resistente a Múltiplos Medicamentos/diagnóstico , Antituberculosos/administração & dosagem , Técnicas de Tipagem Bacteriana , Colorimetria/métodos , Farmacorresistência Bacteriana , Feminino , Humanos , Masculino , Testes de Sensibilidade Microbiana , Mycobacterium tuberculosis/isolamento & purificação , Peru , Estudos de Amostragem , Sensibilidade e Especificidade , Fatores de Tempo , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológicoRESUMO
Objetivo: Conocer las variables clínicas y de laboratorio de más frecuente presentación en pacientes con preeclampsia (PE) de dos hospitales de la Quinta Región. Pacientes y Métodos: Estudio prospectivo caso-control. Se estudiaron 44 mujeres con PE sin patología asociada divididas en dos grupos; uno con 25 embarazadas con PE moderada (PEM) y otro de 19 con PE severa (PES), y grupo control de 30 embarazadas normales. Resultados: El índice de masa corporal basal fue de 24,1 ± 4 para el grupo control, 25,8 ± 5 para el grupo con PEM y 26,1 ± 4 para el grupo PES, diferencias no significativas. La sintomatología clínica fue más frecuente en las pacientes con PES. Los valores de transaminasas y uricemia de ambos grupos con PE fueron mayores y los de plaquetas significativamente menores a los del grupo control. No hubo diferencia significativa en los valores de creatininemia y hematocrito. La proteinuria fue mayor en las pacientes con PES pero en la mayoría de estos se situó en rangos de 0,35 a 1,5 g/l. El Apgar de los recién nacidos fue similar en todos los grupos. Conclusiones: La sintomatología clínica es útil para la detección de PES. Valores de uricemia mayores de 4 mg/dl más cifras tensionales elevadas son altamente sugerente de PE. Un número importante de pacientes con PES presentó proteinuria inferior a 3 g/l, por lo que la ausencia de cifras mayores no debiera excluir la presencia de PES.
Assuntos
Humanos , Feminino , Gravidez , Recém-Nascido , Gravidez/estatística & dados numéricos , Pré-Eclâmpsia/diagnóstico , Pré-Eclâmpsia/epidemiologia , Índice de Massa Corporal , Hematócrito/estatística & dados numéricos , Hipertensão/diagnóstico , Hipertensão/epidemiologia , Transaminases/sangueAssuntos
Doença de Chagas/epidemiologia , Doenças Endêmicas , Adolescente , Adulto , Distribuição por Idade , Idoso , Brasil/epidemiologia , Doença de Chagas/mortalidade , Criança , Pré-Escolar , Hospitalização/estatística & dados numéricos , Humanos , Lactente , Recém-Nascido , Pessoa de Meia-IdadeRESUMO
La deficiencia de hierro es la carencia nutricional más frecuente y la principal causa de anemia en el niño. En un estudio a escala nacional (1974-1975) la prevalencia de anemia en preescolares fue de 18,8 por ciento. Para evaluar la nutrición de hierro, se seleccionaron 96 niños sanos (2 a 5 años) de la comuna La Pintana. Previo consentimiento informado, se obtuvo una muestra de sangre para medir hemoglobina, volumen corpuscular medio, protoporfirina libre eritrocitaria y ferritina sérica. Ninguno de los niños presentó anemia ferropriva o eritropoyesis deficiente en hierro. Sólo un 5,2 por ciento de los sujetos tenía una depleción de los depósitos de hierro. 99 por ciento y 69 por ciento de los niños consumían diariamente pan y leche fortificada (Leche Purita Cereal). Es altamente probable que la mejoría de la nutrición de hierro de los niños se deba al consumo de alimentos fortificados con hierro: harina de trigo y la Leche Purita Cereal distribuida por el Programa Nacional de Alimentación Complementaria
Assuntos
Humanos , Masculino , Pré-Escolar , Feminino , Anemia Ferropriva , Anemia Ferropriva , Chile , Estudos Transversais , Ferritinas , Alimentos Fortificados , Hemoglobinas , Ferro , Estado Nutricional , Protoporfirinas , Fenômenos Fisiológicos da Nutrição do LactenteRESUMO
OBJECTIVE: To assess the prevalence of intermittent claudication in the aged population of Bambuí, Brazil, and to identify the factors associated with this disease. METHODS: Population-based cross-sectional study of the aged population (>/= 60 years of age) of Bambuí. Participants were interviewed and examined, after written consent. Intermittent claudication was defined based on a standardized questionnaire. Analysis was performed using multiple logistic regression. RESULTS: Of the 1,742 elderly living in Bambuí, 1,485 (85.2%) were enrolled in the study. Thirty-seven individuals (2.5%) with intermittent claudication were identified: 28 (1.9%) males and 9 (0.6%) females. Their age brackets were: 16 (1.08%) individuals between 60 and 69 years of age, 17 (1.15%) between 70 and 79 years, and 4 (0.27%) >/= 80 years. A significant association between intermittent claudication and the following characteristics was found: male sex (OR=5.1; CI 2.4-11.0), smokers (OR=3.1; CI 1.2-8.5), ex-smokers (OR=3.4; CI 1.3-8.7), and more than 2 hospital admissions in the last 12 months (OR=2.8; CI 1.1-7.2). CONCLUSION: Disease prevalence was similar to that of other countries. The association between intermittent claudication and smoking strengthens the significance of tobacco in peripheral artery disease pathogenesis. The association of intermittent claudication and a higher number of hospital admissions suggests greater morbidity in the elderly affected.
Assuntos
Claudicação Intermitente/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Brasil/epidemiologia , Estudos Transversais , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Prevalência , Estudos Prospectivos , Fatores de Risco , Inquéritos e QuestionáriosRESUMO
The in vitro activity of thiabendazole on Ascaris lumbricoides eggs, which were recovered from uteri of worm excreted after chemotherapeutic treatment, was studied. Four concentrations of the drug were used: 1 - 2.5 - 5 - and 10 ppm during 24, 48 and 72 hours of exposure. Subsequently, the eggs were centrifuged, washed three times and H(2)SO(4)0.1N was added. The eggs were maintained in an incubator for 20 days at 28 degrees C. Finally, the percentage of embryonated eggs was determined under a lightmicroscope at a 100X magnification. After 48 and 72 hours of thiabendazole exposure, at a concentration of 10ppm, the drug showed complete inhibition of egg embryonation.
Assuntos
Antinematódeos/farmacologia , Ascaris lumbricoides/efeitos dos fármacos , Tiabendazol/farmacologia , Animais , Contagem de Ovos de ParasitasRESUMO
BACKGROUND: The prevalence of Chagas' disease is decreasing in Brazil. Due to cohort effect, the disease might remain a public health problem for some time among older individuals. The present burden of Trypanosoma cruzi infection for the elderly living in areas where the transmission has been interrupted has not been studied. METHODS: The prevalence of T. cruzi infection and its association with indicators of health status and health services use were assessed among the elderly living in one of the oldest endemic areas in Brazil (Bambuí, MG). Seropositivity was determined by blood tests (IHA and ELISA) performed in 85.6% of all residents aged 60+ (1496/1742) and in 83.1% of sampled residents aged 5-59 years (1212/1458). RESULTS: Seropositivity showed a cohort effect, with no cases below 20 years and high prevalence among those aged 60+ years (37.7%). After adjustment for confounders, seropositivity was associated with self-rated health reasonable (OR = 1.43; 95% CI : 1.03-1.98) and bad/very bad (OR = 1.89; 95% CI : 1.30-2.75), staying in bed in past 2 weeks (OR = 1.88; 95% CI : 1.21-2.92), hospitalization in past 12 months (OR = 1.41; 95% CI : 1.05-1.89) and use of 5+ prescribed medications in past 3 months (OR = 1.75; 95% CI : 1.15-2.59). IMPLICATIONS: Our results are an example of how survival of individuals with past exposure to infectious disease may lead to a different picture of ageing in the developing world. Policy makers need to consider the extra burden imposed by increasing rates of non-infectious disease among the elderly (as observed in Brazil) including the consequences of T. cruzi infection in areas where the infection was widespread in the past.
Assuntos
Doença de Chagas/epidemiologia , Adolescente , Adulto , Fatores Etários , Idoso , Brasil/epidemiologia , Doença de Chagas/transmissão , Criança , Pré-Escolar , Estudos de Coortes , Fatores de Confusão Epidemiológicos , Estudos Transversais , Interpretação Estatística de Dados , Ensaio de Imunoadsorção Enzimática , Indicadores Básicos de Saúde , Testes de Hemaglutinação , Humanos , Entrevistas como Assunto , Pessoa de Meia-Idade , Prevalência , Análise de Sobrevida , População UrbanaRESUMO
In the female genital tract, spermatozoa must undergo capacitation and acrosome reaction prior to fertilization. A number of factors may induce physiological acrosome reaction assayed in vitro. The aims of this study are to determine the inductive effect of the preovulatory follicular fluid on the sperm acrosomal status in the equine, once some characteristics of the follicular fluid during folliculogenesis had been evaluated. The spermatozoa were obtained from cauda epididymes of adult stallion. Follicular fluid was taken from mare ovarian follicles classified according to their diameter. In these fluids, total protein, progesterone, estradiol and osmolarity were determined. Afterwards, the effect of preovulatory follicular fluid (50) upon induction of the acrosomic reaction in stallion capacitated spermatozoa was assayed. Results show that during folliculogenesis the ratio progesterone/estrogen is below 1. In large preovulatory follicles, there is a sharp increase of progesterone, reaching a ratio progesterone/estrogen close to 4. Protein concentration and osmolarity increase together with follicular development, being osmolarity very high at the preovulatory stage. Follicular fluid--in vitro--increases the percentage of spermatozoa with acrosome reaction, maintaining high rates of vitality and motility. The characteristics of follicular fluid undergo dynamic changes during the folliculogenesis, such as steroid level, protein concentration and osmolarity. These events may play a role in the reproductive process in vivo, considering that in vitro the follicular fluid is a very effective inductor of the acrosome reaction, with optimum levels of vitality and motility.(AU)