RESUMO
The acaricidal effect of 14 strains of Metarhizium anisopliae sensu lato isolated from soil of livestock farms in the Mexican tropics was evaluated against larvae and engorged females, and during the laying and hatching of eggs of Rhipicephalus microplus (Ixodida: Ixodidae). For each fungal strain, the larvae mortality percentage was evaluated through a larval immersion test, while the reproductive efficiency indices in engorged females were measured using adult immersion tests at a dose of 1 × 108 conidia/ml. All strains of M. anisopliae (s.l.) proved to be highly effective against R. microplus larvae (66-100%) and engorged females (100%). The strains also showed a good effect in inhibiting egg laying (16.45-56.38%) and a moderate effect in decreasing egg hatching (5.24-32.68%). Two strains demonstrated to be effective against all development phases of R. microplus in an integrated manner.
Assuntos
Metarhizium , Rhipicephalus , Animais , Feminino , Rhipicephalus/microbiologia , Gado , Larva/microbiologia , Controle Biológico de Vetores , ReproduçãoRESUMO
The cattle tick Rhipicephalus microplus (Acari: Ixodidae) has demonstrated its ability to increase its distribution raising spatially its importance as a vector for zoonotic hemotropic pathogens. In this study, a global ecological niche model of R. microplus was built in different scenarios using Representative Concentration Pathway (RCP), Socio-Economic Pathway (SSP), and a climatic dataset to determine where the species could establish itself and thus affect the variability in the presentation of the hemotropic diseases they transmit. America, Africa and Oceania showed a higher probability for the presence of R. microplus in contrast to some countries in Europe and Asia in the ecological niche for the current period (1970-2000), but with the climate change, there was an increase in the ratio between the geographic range preserved between the RCP and SSP scenarios obtaining the greatest gain in the interplay of RCP4.5-SSP245. Our results allow to determine future changes in the distribution of the cattle tick according to the increase in environmental temperature and socio-economic development influenced by human development activities and trends; this work explores the possibility of designing integral maps between the vector and specific diseases.
Assuntos
Doenças dos Bovinos , Ixodidae , Rhipicephalus , Infestações por Carrapato , Humanos , Bovinos , Animais , Mudança Climática , Infestações por Carrapato/veterináriaRESUMO
The southern cattle tick Rhipicephalus microplus is a major problem for the cattle industry in tropical and subtropical areas worldwide. Chemical products are commonly applied to control it; however, their indiscriminate use has resulted in the appearance of resistant lineages. In the last decades, plants have been used as an alternative to conventional acaricidal drugs, as several plant compounds repel activity, decrease the reproductive potential and reduce the survival rate of ticks. For this reason, the in vitro efficacy of hexanic and hydroalcoholic extracts of Randia aculeata, Moringa oleifera and Carica papaya were evaluated against the larvae and engorged females of R. microplus. Larval packet tests and adult immersion tests were performed with seven concentrations of each of the extracts. The extracts obtained with hydroethanolic solution (polar solvent) exhibited a higher acaricidal activity than extracts prepared with n-hexane (non-polar solvent). Hydroethanolic extracts of R. aculeata seed and shell showed the highest larvicidal activity against R. microplus (100 and 91% mortality, respectively) at a concentration of 100 mg/mL. Randia aculeata (seed and shell), M. oleifera and C. papaya treatments at the same concentration (100 mg/mL) also resulted in adult mortality of 85, 75, 66 and 55%, respectively. The adult immersion test showed that hydroethanolic extracts derived from R. aculeata seed significantly reduced the index of egg laying and increased the percentage inhibition of oviposition of female ticks at a concentration of 100 mg/mL. These results indicate that the tested extracts exhibit acaricidal activity and could be considered as potential agents for the development of alternative natural acaricides against R. microplus.
Assuntos
Acaricidas , Ixodidae , Plantas Medicinais , Rhipicephalus , Animais , Larva , Extratos Vegetais/farmacologiaRESUMO
Zoonotic tick-borne diseases, including those caused by Rickettsia species, continue to have serious consequences for public health worldwide. One such disease that has emerged as a major problem in several countries of the American continent is the Rocky Mountain Spotted Fever (RMSF) caused by the bacterium Rickettsia rickettsii. Several tick species are capable of transmitting R. rickettsia, including Amblyomma cajennense, A. aureolatum, A. imitator, Rhipicephalus sanguineus, Dermacentor andersoni, D. variabilis and possibly A. americanum. Despite previous reports in Mexico linking new outbreaks of RMSF to the presence of these tick species, no robust measures have tackled transmission. In the present study, we amplified R. rickettsii from 109 test DNA samples extracted from ticks collected from several animals and humans of Tamaulipas, Mexico, between November 2015 and December 2017. Our analysis revealed the presence of R. rickettsii in six samples and these findings contribute to a spatial distribution map that is intended to minimize the risk of transmission to humans.
Assuntos
Ixodidae/microbiologia , Rickettsia rickettsii/isolamento & purificação , Animais , Humanos , México , Febre Maculosa das Montanhas Rochosas , Estados UnidosRESUMO
The genus Leptospira encompass 22 species of spirochaetes, with ten pathogenic species that have been recorded in more than 160 mammals worldwide. In the last two decades, the numbers of records of these agents associated with bats have increased exponentially, particularly in America. Although order Chiroptera represents the second most diverse order of mammals in Mexico, and leptospirosis represents a human and veterinary problem in the country, few studies have been conducted to identify potential wildlife reservoirs. The aim of this study was to detect the presence and diversity of Leptospira sp. in communities of bats in an endemic state of leptospirosis in Mexico. During January to September 2016, 81 bats of ten species from three localities of Veracruz, Mexico, were collected with mist nets. Kidney samples were obtained from all specimens. For the detection of Leptospira sp., we amplified several genes using specific primers. Amplicons of the expected size were submitted to sequencing, and sequences recovered were compared with those of reference deposited in GenBank using the BLAST tool. To identify their phylogenetic position, we realized a reconstruction using maximum-likelihood (ML) method. Twenty-five samples from three bat species (Artibeus lituratus, Choeroniscus godmani and Desmodus rotundus) showed the presence of Leptospira DNA. Sequences recovered were close to Leptospira noguchii, Leptospira weilii and Leptospira interrogans. Our results include the first record of Leptospira in bats from Mexico and exhibit a high diversity of these pathogens circulating in the state. Due to the finding of a large number of positive wild animals, it is necessary to implement a surveillance system in populations of the positive bats as well as in related species, in order to understand their role as carriers of this bacterial genus.
Assuntos
Quirópteros/microbiologia , Leptospira/isolamento & purificação , Leptospirose/veterinária , Animais , DNA Bacteriano/genética , Reservatórios de Doenças/microbiologia , Rim/virologia , Leptospira/classificação , Leptospirose/epidemiologia , Leptospirose/microbiologia , México/epidemiologia , Filogenia , Reação em Cadeia da Polimerase/veterinária , RNA Ribossômico 16S/genéticaRESUMO
Biofilms correspond to complex communities of microorganisms embedded in an extracellular polymeric matrix. Biofilm lifestyle predominates in Pseudomonas aeruginosa, an opportunistic Gram negative pathogen responsible for a wide spectrum of infections in humans, plants and animals. In this context, anti-biofilm can be considered a key strategy to control P. aeruginosa infections, thereby more research in the field is required. On the other hand, Lactobacillus species have been described as beneficial due to their anti-biofilm properties and their consequent effect against a wide spectrum of pathogens. In fact, biofilm-forming Lactobacilli seem to be more efficient than their planktonic counterpart to antagonise pathogenic bacteria. In this work, we demonstrated that Lactobacillus kunkeei, a novel Lactobacillus species isolated from honeybee guts, can form biofilms in vitro. In addition, the L. kunkeei biofilm can, in turn, inhibit the formation of P. aeruginosa biofilms. Finally, we found that L. kunkeei strains attenuate infection of P. aeruginosa in the Galleria mellonella model, presumably by affecting P. aeruginosa biofilm formation and/or their stability. Since L. kunkeei presents characteristics of a probiotic, this work provides evidence arguing that the use of this Lactobacillus species in both animals (including insects) and humans could contribute to impair P. aeruginosa biofilm formation.
Assuntos
Biofilmes/crescimento & desenvolvimento , Lactobacillus/fisiologia , Mariposas/microbiologia , Probióticos , Pseudomonas aeruginosa/fisiologia , Animais , Lactobacillus/crescimento & desenvolvimento , Pseudomonas aeruginosa/crescimento & desenvolvimentoRESUMO
Water buffaloes (Bubalus bubalis) were introduced to Mexico at the end of the last century. In Mexico, buffaloes are commonly pastured together with cattle; however few studies have been done on buffalo herd health in Mexico. We hypothesized that a better knowledge of the epidemiology of infections shared between cattle and buffaloes may improve herd profitability and promote buffalo production in areas unsuitable to cattle farming. This study aimed to determine the prevalence of antibodies against bovine herpes virus - 1 (BoHV1) in water buffaloes raised on six farms from the state of Veracruz, Mexico. Of 368 buffaloes sampled, 217 (59%) were seropositive for BoHV-1. Age was identified as a risk factor for BoHV-1 infection with buffaloes older than 5 years being the most likely to be infected. Animals more than 7 years old had the highest prevalence (86.0%). Females and males had similar seroprevalence rates. Females with history of abortion had higher prevalence of antiBoHV-1 antibodies than those with no record of abortion. Buffaloes and cattle were raised together in only one of the six farms under study. Interaction with cattle was not a risk factor for BoHV-1 seropositivity. This study showed that BoHV-1 is prevalent among buffalo herds in the state of Veracruz, Mexico. Buffaloes appear to play an important role in the epidemiology of BoHV-1 infection in parts of Mexico when there is no apparent risk of interaction with cattle. Animal health programs established to mitigate the burden caused by BoHV-1 must take into consideration buffaloes when this bovid species is part of the agroecosystem shared with cattle.
RESUMO
Activation of the growth hormone (GH) secretagogue receptor (GHS-R) by synthetic GH releasing peptides (GHRP) or its endogenous ligand (Ghrelin) stimulates GH release. Though much is known about the signal transduction underlying short-term regulation, there is far less information on the mechanisms that produce long-term effects. In the current report, using an enzyme-linked immunosorbent assay for GH detection and whole-cell patch-clamp recordings, we assessed the long-term actions of such regulatory factors on voltage-activated Ca(2+) currents in bovine somatotropes (BS) separated on a Percoll gradient and detected by immunohistochemistry. After 24 h of treatment with Ghrelin (10 nM) or GHRP-6 (100 nM) enhanced BS secretory activity; GH secretion stimulated by GHS through the activation of GHS-R because treatment with the antagonist of GHS-R (D-Lys3-GHRP-6, 10 µM) blocked the GH secretion, and the effect was dose and time dependent (24, 48, and 72 h). GH secretion stimulated by GHRP-6 was abolished by nifedipine (0.5 µM), a blocker of L-type HVA Ca(2+) channels, and KN-62 (10 µM), an inhibitor of Ca(2+)/CaM-KII. After 72 h in culture, all recorded BS exhibited two main Ca(2+) currents: a low voltage-activated (LVA; T-type) and a high voltage-activated (HVA; mostly dihydropyridine-sensitive L-type) current. Interestingly, HVA and LVA channels were differentially upregulated by Ghrelin. Chronic treatment with the GHS induced a significant selective increase on the Ba(2+) current through HVA Ca(2+) channels, and caused only a small increase of currents through LVA channels. The stimulatory effect on HVA current density was accompanied by an augment in maximal conductance with no apparent changes in the kinetics and the voltage dependence of the Ca(2+) currents, suggesting an increase in the number of functional channels in the cell membrane. Lastly, in consistency with the functional data, quantitative real-time RT-PCR revealed transcripts encoding for the Cav1.2 and Cav1.3 pore-forming subunits of L-type channels. The treatment with Ghrelin significantly increased the Cav1.3 subunit expression, suggeting that the chronic stimulation of the GHS receptor with Ghrelin or GHRP-6 increases the number of voltage-gated Ca(2+) channels at the cell surface of BS.
RESUMO
El 3 por ciento de todas las lesiones en trauma tiene un componente vascular. Con los conflictos armados del siglo pasado se lograron grandes avances en este campo. A partir de la Guerra de Vietnam gracias a las mejoras en el manejo prehospitalario, traslado de pacientes, y avances en técnica quirúrgica se lograron tasas de sobrevida y de amputaciones que se han mantenido estables hasta la fecha. El diagnóstico de lesiones vasculares en extremidades se realiza con el examen físico, sin embargo las lesiones de vasos torácicos y abdominales requieren de imágenes de apoyo, siempre que el paciente se encuentre estabilizado, generalmente tomografía axial computada. La mayoría de las lesiones vasculares son por trauma penetrante, comprometiendo principalmente las extremidades. Con el desarrollo de los procedimientos invasivos vasculares en los últimos años se ha observado un aumento de lesiones vasculares iatrogénicas. Hoy en día muchos pacientes con trauma vascular son manejados por vía endovascular.
3 percent of all injuries in trauma have a vascular component. With the armed conflicts of the last century great progress was made in this field. From the Vietnam War, due to improvements in prehospital management, transfer of patients, and advances in surgical technique, survival and amputations rates achieved back then have been stable to date. The diagnosis of vascular injuries in extremities is performed by physical examination, however injuries of thoracic and abdominal vessels require imaging support, provided the patient is stabilized, usually axial computed tomography. Most vascular injuries are penetrating trauma, compromising mainly the extremities. The development of vascular invasive procedures in recent years have seen an increase in iatrogenic vascular injuries. Today, many patients with vascular trauma are managed by endovascular surgery.
Assuntos
Humanos , Ferimentos e Lesões , Lesões do Sistema Vascular/diagnóstico , Lesões do Sistema Vascular , Traumatismos Torácicos , Ferimentos PenetrantesRESUMO
El esfuerzo del científico Moisés Santiago Bertoni por sistematizar parte de la riqueza que tiene el Paraguay, se refleja en la Stevia rebaudiana Bertoni, (Ka'a He'ê), una planta que hace parte de la identidad como nación, pero que al mismo tiempo, luego de un siglo, sigue siendo promisoria como elemento fundamental para la implementación de un modelo de desarrollo sostenible en áreas rurales.
The effort of the scientific Moisés Santiago Bertoni to systematize part of the richness of Paraguay is reflected in the Stevia rebaudiana Bertoni, (Ka'a He'ê). This plant makes part of the identity of the nation but at the same time, after a century, is still promising as an essential element for the implementation of a sustainable development model in rural areas.
Assuntos
Edulcorantes , SteviaRESUMO
El uso de fleboesclerosis para el tratamiento de las várices es una antigua técnica con un rango de indicaciones claramente establecido, que ha recobrado vigencia en este último tiempo. Como toda técnica invasiva presenta complicaciones inherentes al fármaco: pigmentación de la piel, trombosis venosa profunda, embolia pulmonar, o dependientes de la técnica de punción, donde la más temida es la necrosis por inyección arterial del medio esclerosante. Se presenta un caso clínico de necrosis distal de extremidad inferior, con pérdida del antepié, y manejado con trombólisis en forma tardía. Se describen las opciones terapéuticas, remarcándose la importancia de realizar terapias invasivas por profesionales adecuadamente entrenados en las técnicas y manejo de sus complicaciones, las que si se presentan, deben ser abordadas por un especialista a la brevedad, ya que es la única manera de evitar exéresis o grandes pérdidas de tejido
Assuntos
Humanos , Feminino , Idoso , Necrose Tubular Aguda , Escleroterapia , Varizes , Pé , Necrose Tubular Aguda , Soluções Esclerosantes , Estreptoquinase , Terapia TrombolíticaRESUMO
Fifty years of geomorphologic change in Damas Island, Quepos, Costa Rica, were studied from a photographic record that is available since 1947. Coastal dynamics were accelerated by the El Niño Phenomenon in 1997 which was simultaneous with the August-September astronomical tide, one of the highest in the 4-5 year cycle. Additionally, waves with high energy were present in some periods of these months. Processes were enough to break the island in two blocks and to initialize erosion and transport sediment that continues to date. The frequency of tropical storms and the wave energy will be greater in the next years increasing sediment instability processes in parts of the island. Two topographic profiles have shown that the island is not in equilibrium and that adding all the possible mareographic components it will be prone to continued erosion. The marine habitats around the island should be changing because the fresh and salt water input has been modified, specially because alteration in the Parrita and Paquita hydrological river basins, and its effects on the sediments of this system.
RESUMO
PURPOSE: To assess the seroprevalence of IgG and IgM specific for parvovirus B19 (B19) and its association with aplastic crisis developing in patients with different haematological disorders. PATIENTS AND METHODS: Fifty-three serum samples were evaluated, 24 from patients with aplastic crisis and 29 from others without such crises, all of them suffering from different haematological diseases diagnosed at the University Hospital of Maracaibo and the Zulia State Blood Bank, in Venezuela; 15 samples from healthy blood donors were examined as well. Indirect immunofluorescence technique was used in the study. Lymphocyte subsets were quantified in 10 of the patients with aplastic crisis by means of cytofluorometry. Serum proteins were assessed by electrophoresis in all samples. The statistical analysis was performed according to Student's t test and chi square, by applying the statix 4.0 and SAS programmes. RESULTS: Positive IgG was found in 20 of the 24 patients with aplastic crisis (83.3%), 20 of the 29 without crisis (68.9%) and 7 of the 15 healthy controls (46.6%). Positive IgM was found only in 2 of the 24 patients with aplastic crisis (8.3%). Both the patients without aplastic crises and the control groups were negative for PB19 IgM. The average CD4 and CD8 T lymphocyte count and the CD4-CD8 index in the patients studied were 454 CD4 cells/microL, 1,006 CD8 cells/microL and 0.5%, significantly different from the control group, whose figures were 860 CD4 cells/microL, 546 CD8 cells/microL and 1.6%. The average B lymphocyte count of the patients (628 cells/microL) was higher than that of the control group (349 cells/microL). The average NK cell count in the patient was 174 cells/microL, slightly below the control group (221 cells/microL). Mild beta-globulin decrease was found in the electrophoretic study of the serum proteins of the patients, along with significant increase of the total protein and the gammaglobulin fraction with regard to the control group. CONCLUSIONS: Higher PB19 IgG seropositivity was seen in the patients with aplastic crisis with respect to the control group, suggesting wider exposition to the virus among them with regard to the healthy population. Specific PB19 IgM was detected in 2 patients with immunodeficiency and aplastic crisis. A significant decrease of the CD4 and CD8 T-lymphocyte subsets, along with decreased CD4-CD8 quotient, were found in the aplastic crisis group, and an impairment of the immune response to the viral challenge can be inferred form this. The alterations of the serum proteins, together with the increased B lymphocytes, might suggest a polyclonal activation of these cells. The absence of other known lymphotropic viruses in most of the patients studied (50) show that the alterations found here are related to recent or past B19 infection.
Assuntos
Bancos de Sangue , Doadores de Sangue , Parvovirus B19 Humano/isolamento & purificação , Anemia Aplástica/prevenção & controle , Anticorpos Antivirais/análise , Bancos de Sangue/normas , Eletroforese das Proteínas Sanguíneas , Feminino , Técnica Indireta de Fluorescência para Anticorpo , Humanos , Imunoglobulina G/análise , Imunoglobulina M/análise , Masculino , Infecções por Parvoviridae/epidemiologia , Venezuela/epidemiologiaRESUMO
La hemorragia digestiva baja masiva sigue siendo un problema difícil de resolver, a pesar de los avances en técnicas diagnósticas. Los tumores de intestino delgado constituyen sólo el 1-3 porciento de los tumores del tracto digestivo, y las lesiones intestinales en general conforman el 5 por ciento del total de las causas de hemorragias digestivas bajas. A pesar de su baja frecuencia, estos tumores, cuando se oresentan, plantean dificultad en su diagnóstico y tratamiento. Dado lo infrecuente de su aparición y por el desafío diagnóstico y terapéutico que plantean, se presentan dos casos de leiomiomas de yeyuno que debutaron como hemorragia digestiva masiva de origen desconocido y que fueron resueltas finalmente en forma quirúrgica
Assuntos
Humanos , Feminino , Pessoa de Meia-Idade , Hemorragia Gastrointestinal/etiologia , Neoplasias do Jejuno/complicações , Leiomioma/complicações , Neoplasias do Jejuno/patologia , Neoplasias do Jejuno/cirurgia , Leiomioma/patologia , Leiomioma/cirurgiaRESUMO
A case of essential thrombocytemia treated with alpha interferon is reported, with hematological remission, but as a side effect hypertriglyceridemia is relevant. It was normalized when alpha interferon was stopped. This is the first case of essential thrombocythemia in Venezuela treated with biological modifiers, with hematological remission, but with hypertriglyceridemia as side effect.
Assuntos
Hipertrigliceridemia/induzido quimicamente , Fatores Imunológicos/efeitos adversos , Interferon-alfa/efeitos adversos , Trombocitemia Essencial/terapia , Adulto , Alopurinol/uso terapêutico , Feminino , Humanos , Hidroxiureia/uso terapêutico , Fatores Imunológicos/uso terapêutico , Interferon-alfa/uso terapêutico , Indução de Remissão , Trombocitemia Essencial/sangueRESUMO
Malnutrition in children is a well known critical factor that determines immunocompetence changes with altered immune response and higher risk to many diseases, especially in developing countries. Moreover, it is related to increased morbi-mortality rates mainly due to infections. For those reasons, 12 undernourished children, age 5 to 24 months were studied along 8 weeks at the Nutritional Recovery Center of Chiquinquira Hospital in Maracaibo, Venezuela. There were 5 cases of kwashiorkor, 5 marasmatics, 1 mixed marasmus/kwashiorkor and 1 case with moderate malnutrition. After a control blood sample was taken and cutaneous tests were done, a nutritional recovery program was began. At regular time intervals and at the end of the study, tests were done again by measuring seric immunoglobulins (IgG, IgA, IgM), secretory IgA (IgAs), C3 and C4 complement, lymphocytic sub-populations, and auto antibodies; cutaneous hipersensitivity tests were also done. As a control group, 10 apparently healthy children of matching age and sex were also studied with the same parameters. Results show that basal seric Igs did not differ significantly from the control group and did not change along the recovery program period, but there was a significant decrease in IgAs at all times of the study. C4 did not change and C3 was lower than control (p < 0.05) but returned to normal value at the end of the recovery period. CD3 and CD4 lymphocytes showed the same pattern. Only two patients showed positive skin tests and auto antibodies were not detected. It is concluded that there is indeed an altered immune competence with low levels of C3, IgAs, and CD3-CD4 lymphocytes that is reversible after nutritional recovery.
Assuntos
Distúrbios Nutricionais/imunologia , Antígenos CD/sangue , Humanos , Imunoglobulinas/sangue , Lactente , Estudos Longitudinais , Distúrbios Nutricionais/sangue , Distúrbios Nutricionais/terapiaRESUMO
Presentamos un nuevo modelo de inducción de pancreatitis aguda en ratas basado en el modelo del asa duodenal pero que, a diferencia de aquel, produce una pancreatitis de caracter obstructivo y no por reflujo. A 24 ratas Sprague-Dawley machos, se les indujo PA, introduciendo a través de una duodenotomía un tubo de polietileno que produce obstrucción de los conductos biliar y pancreático, manteniendo el tránsito alimentario desde el estómago hacia distal. El 100 porciento de las ratas presentó una pancreatitis de caracter necrohemorrágico con alteración de los parámetros bioquímicos e histopatológicos. Hemos desarrollado un nuevo modelo de PA de tipo obstructivo en ratas, en el cual postulamos una serie de mecanismos de producción, entre los cuales estarían involucrados los radicales libres de oxígeno (RLO), contribuyendo al desarrollo de eventos a diferentes niveles, que llevarían a daño celular irreversible. Resta aún dilucidar en qué momento comienza a producirse los cambios propios de la PA y si la PA intersticial y necrohemorrágica son estadios evolutivos de una misma entidad patológica o son enfermedades diferentes
Assuntos
Animais , Ratos , Pancreatite/fisiopatologia , Radicais Livres , Pâncreas/patologia , Ratos Sprague-DawleyRESUMO
Madin-Darby canine kidney and other epithelial cell lines (e.g. Caco-2, MCF-10A and MCF-7) develop intracellular vacuoles composed of apical membrane displaying microvilli (VACs) when impaired from forming normal cell-to-cell contacts. In a previous publication, we showed that VACs are rapidly exocytosed upon treatment with 8-Br-3',5'-cyclic adenosine monophosphate (8-Br-cAMP), a membrane-permeable analog of cAMP, and that this exocytosis correlates with variations in the cellular cAMP concentration in response to the cell-cell contacts. In the present work, we tested the hypothesis that cAMP may be a positive modulator of the 'constitutive' exocytic pathway. To mimic conditions in cells with incomplete intercellular contacts, the intracellular levels of cAMP were decreased by means of two independent approaches: (i) pores were induced in the plasma membrane with the polypeptidic antibiotic subtilin, thus allowing small molecules (including cAMP) to permeate and move out of the cytoplasm; and (ii) adenylate cyclase and protein kinase A were blocked with specific inhibitors. In all cases, the intracellular levels of cAMP were measured and, in porated cells, equilibrated to simulate the corresponding physiological intracellular concentrations. The decrease in cAMP within the physiological range resulted in a decreased rate of transport of an apical marker of the constitutive pathway (influenza virus hemagglutinin) from the trans-Golgi network to the apical plasma membrane. Likewise, the delivery of a number of cellular apical proteins to the plasma membrane was retarded at low cAMP concentrations. The inhibitors of adenylate cyclase failed to block basolateral delivery of vesicular stomatitis virus G protein. This differential modulatory effect may represent a differentiation-dependent control of the insertion of apical membrane in epithelial cells.
Assuntos
Proteínas de Bactérias , AMP Cíclico/fisiologia , Exocitose , Glicoproteínas de Membrana , Proteínas de Membrana/metabolismo , Peptídeos , 8-Bromo Monofosfato de Adenosina Cíclica/farmacologia , Adenosina/análogos & derivados , Adenosina/farmacologia , Inibidores de Adenilil Ciclases , Adenilil Ciclases/metabolismo , Animais , Antibacterianos/farmacologia , Bacteriocinas , Transporte Biológico , Linhagem Celular , Polaridade Celular , AMP Cíclico/análogos & derivados , AMP Cíclico/farmacologia , Proteínas Quinases Dependentes de AMP Cíclico/antagonistas & inibidores , Cães , Epitélio , Exocitose/efeitos dos fármacos , Glicoproteínas de Hemaglutininação de Vírus da Influenza , Hemaglutininas Virais/metabolismo , Rim , Microvilosidades/metabolismo , Tionucleotídeos/farmacologia , Vacúolos/metabolismo , Vidarabina/farmacologia , Proteínas do Envelope Viral/metabolismoRESUMO
PURPOSE: Some genetic factors associated to the HLA system phenotypes may allegedly predispose to the development of infection in patients exposed to the human immunodeficiency virus (HIV). So the aim of this study was to assess if certain HLA antigens are positive or negative risk factors in the development of AIDS in Zulia State. PATIENTS AND METHODS: A total of 62 samples were studied, 31 from HIV seropositive subjects and 31 form healthy individuals. The patients were subclassified into four groups in accordance with Atlanta's CDC guidelines. Tests for histocompatibility including HLA-A-B-C, DR and DQ typing were performed with Terasaki's technique. VIH positivity was determined by ELISA and confirmed by Western Blot. The statistical evalub1p4n was performed with the chi 2 test for antigen frequency comparison, the relative risk (RR) was estimated with the Ryder and Svelgaard test, and the inferential analysis was made by means of non-parametric statistics. RESULTS: Most patients were included in CDC's groups II and IV, 48.4% and 29.0%, respectively. Increased B35 and DQw2 and decreased B39 and DR2 antigens were found when comparing the HLA distribution in the sample and the antigenic frequency of the population. RR > 1 was observed in the infected patients A for A1, A3, A10, A11, B5, B7, B12, B14, B35, B61, CW4, DR4, DRW52 and DQW2 HLA antigens. A positive association between symptomatic infected patients and antigen B35 was present (X = 7.045). CONCLUSION: The findings reported here suggest that antigen B35 is a major risk factor for the development of AIDS.