Tick-borne pathogens infecting dogs from a highland swamp area / [Infecção em cães por patógenos transmitidos por carrapatos em uma área de brejo de altitude]

Objetivou-se neste estudo relatar a frequência e a identidade de patógenos transmitidos por carrapatos em cães residentes de uma área caracterizada por brejo de alta altitude. Amostras sanguíneas (n=203) foram coletadas e molecularmente analisadas via PCR (Babesia spp., Hepatozoon spp., Anaplasma spp. e Ehrlichia spp.) e sequenciamento de DNA. De todas as amostras analisadas, 8,87% (18/203) foram positivas a algum patógeno transmitido por carrapato. Especificamente, 5,42% (11/203) e 3,45% (7/203) foram positivos a Anaplasma platys e Ehrlichia canis, respectivamente. Este estudo fornece, pela primeira vez, evidência científica de infecção de cães por esses patógenos nessa área de alta altitude e reforça o provável papel de R. sanguineus s.l. como vetor de A. platys, principalmente considerando.se que muitos animais positivos eram infestados por essa espécie de carrapato.(AU)

Prevalence of infection by Cryptosporidium spp. in calves and associated risk factors in Northeastern Brazil / [Prevalência da infecção por Cryptosporidium spp. e fatores de risco associados em bezerros do Nordeste do Brasil]

Cryptosporidium spp. are zoonotic protozoa, frequently associated with diarrhea in calves, which are responsible for important economic losses. The aim of this study was to assess the prevalence of infection by Cryptosporidium spp. and its associated risk factors among calves raised in a milk production region of Northeastern Brazil. Fecal samples (n = 385) were obtained from young animals (up to ten months old) and evaluated by means of centrifugal fecal sedimentation in formalin-ether followed by the modified Ziehl-Neelsen staining technique. In addition, Odds Ratio (OR) was calculated to evaluate associations between variables and infection by these protozoa. Out of all samples analyzed, 25.7% (99/385) scored positive for the presence of Cryptosporidium spp. Contact with other species (goat and sheep) (OR = 3.33; p = 0.000), use of a semi-intensive rearing system (OR = 1.70; p = 0.024) and absence of hygienic conditions (fecal contamination of food and water) (OR = 1.64; p = 0.029) were considered to be risk factors. Data herein reported shows that the implementation of hygienic-sanitary measures on the farms studied, it is imperative to reduce Cryptosporidium spp. infection and consequently the economic impact caused by this pathogen.(AU)

Cryptosporidium spp. são protozoários zoonóticos frequentemente associados à diarreia em bezerros e responsáveis por importantes perdas econômicas. O objetivo deste estudo foi avaliar a prevalência e os fatores de risco associados à infecção por Cryptosporidium spp. em bezerros de propriedades leiteiras no Nordeste do Brasil. Amostras fecais (n = 385) foram obtidas de animais jovens (até 10 meses de idade) e avaliadas por centrífugo-sedimentação em formol éter, seguida da técnica de coloração de Ziehl-Neelsen modificada. A Odds Ratio (OR) foi calculada para avaliar a associação entre variáveis e infecção pelos protozoários. De todas as amostras analisadas, 25,7% (99/385) apresentaram oocistos de Cryptosporidium spp. Contato com outras espécies (caprino e ovino) (OR = 3,33; p = 0,000), sistema semi-intensivo de criação (OR = 1,70; p = 0,024) e ausência de condições higiênicas (contaminação fecal do alimento e da água) (OR = 1,64; p = 0,029) foram considerados fatores de risco. Com base nos resultados, é imprescindível a adoção de medidas higiênico-sanitárias nas fazendas estudadas, a fim de reduzir infecção por Cryptosporidium spp. e o impacto econômico causado por esse patógeno.(AU)

Ectoparasites infesting animals living in close contact with human beings: a real trouble for One Health perspective? / [Ectoparasitos infestando animais que vivem em contato próximo com seres humanos: um problema real para a perspectiva Saúde Única?]

The number of domestic animals living with human beings is rapidly increasing in parallel with an enhanced risk of transmission of their parasites and the pathogens they might carry. The aim of this study was to assess the occurrence of hematophagous arthropods infesting domestic animals from Northeastern Brazil and to remark the implications of their occurrence on the epidemiology and control of selected veterinary and human diseases. From January 2017 to April 2019, ectoparasites infesting domestic cats, dogs and horses were collected for their respective hosts and identified. Overall, ectoparasites were sampled from 86 domestic animals, living in different anthropic settings. A total of 401 specimens (344 ticks and 57 fleas) were collected from different hosts [i.e., 10 (2.49%), 96 (23.94%) and 295 (73.57%) from cats, dogs and horses, respectively]. Two flea (i.e., Ctenocephalides canis and Ctenocephalides felis) and 5 tick species (i.e., Amblyomma ovale, Amblyomma sculptum, Dermacentor nitens, Rhipicephalus microplus and Rhipicephalus sanguineus sensu lato) were identified. This study provides data on the ectoparasite fauna infesting domestic animals from Northeastern Brazil. The diagnosis and treatment of these parasites should not be underestimated, considering the role that hematophagous arthropods display as vectors of pathogens of medical and veterinary concern.(AU)

O número de animais domésticos infestados por ectoparasitos vivendo em estreito contato com seres humanos está aumentando, elevando o risco de infecção pelos patógenos transmitidos por vetores. Objetivou-se neste estudo avaliar a ocorrência de ectoparasitos infestando animais do nordeste do Brasil e discutir as implicações desse parasitismo na epidemiologia e no controle de doenças de importância médico-veterinária. De janeiro de 2017 a abril de 2019, artrópodes foram coletados de gatos, cães e cavalos, e identificados morfologicamente. Ectoparasitos foram removidos de 86 animais infestados provenientes de áreas urbanas e rurais. Foram identificados 401 espécimes (344 carrapatos e 57 pulgas) coletados de diferentes hospedeiros (10 (2,49%), 96 (23,94%) e 295 (73,57%) de gatos, cães e cavalos, respectivamente. Duas espécies de pulgas (Ctenocephalides canis e Ctenocephalides felis) e cinco espécies de carrapatos (Amblyomma ovale, Amblyomma sculptum, Dermacentornitens, Rhipicephalus microplus e Rhipicephalus sanguineus sensu lato) foram identificadas. Este estudo fornece informações sobre a ectofauna de animais domésticos do nordeste do Brasil. Portanto, o diagnóstico e o tratamento desses parasitos não devem ser subestimados, considerando que os artrópodes aqui relatados podem veicular patógenos de importância médico-veterinária.(AU)

Microfilaremia by Cercopithifilaria bainae in a dog from the central western region of Brazil: case report / Microfilaremia por Cercopithifilaria bainae em um cão da região Centro-Oeste do Brasil: relato de caso

Cercopithifilaria bainae is a nematode belonging to the family Onchocercidae that parasitizes the subcutaneous tissue of dogs. Its transmission occurs through the tick Rhipicephalus sanguineus and its geographical distribution overlaps that of this vector. The present study reports the detection of microfilaremia by C. bainae in an eight-year-old male dog that presented anorexia, hyperthermia, motor incoordination, mydriasis, a nodule in the left testicle and concomitant infection by Ehrlichia sp. Blood samples were analyzed using microscopy, PCR and DNA sequencing. Microfilariae measuring 150±5.5µm in length and 7±1.8µm in width were retrieved. The DNA sequence exhibited 98% identity with C. bainae sequences available in Genbank. This is the first report of microfilaremia by C. bainae in a dog in the central western region of Brazil.(AU)

Cercopithifilaria bainae é um nematoide pertencente à família Onchocercidae, que parasita o tecido subcutâneo de cães. Sua transmissão ocorre pelo carrapato Rhipicephalus sanguineus, e sua distribuição geográfica se sobrepõe ao espalhamento desse vetor. O presente estudo relata a detecção de microfilaremia por C. bainae em um cão macho de oito anos que apresentava anorexia, hipertermia, incoordenação motora, midríase e nódulo no testículo esquerdo e infecção concomitante por Ehrlichia sp. A coleta de sangue foi realizada, e o material analisado por meio dos exames de microscopia, PCR e sequenciamento de DNA. Microfilárias medindo 150±5,5µm de comprimento e 7±1,8µm de largura foram recuperadas. A sequência de DNA obtida mostrou 98% de identidade com sequências de C. bainae disponíveis no Genbank. Este é o primeiro relato de microfilaremia de C. bainae em um cão na região Centro-Oeste do Brasil.(AU)

Dairy cows fed on tropical legume forages: effects on milk yield, nutrients use efficiency and profitability.

Two trials with multiparous dairy cows were conducted. Experiment 1 tested the effects of increasing forage proportion in the diet (500, 600, and 700 g/kg DM) when a mixed sorghum (Sorghum bicolor) and jackbean (Cannavalia ensiformis) silage was used as forage. Experiment 2 studied the substitution of sorghum silage and soybean meal by jackbean silage or fresh cowpea (Vigna unguiculata) forage in the diet. All diets were iso-energetic and iso-proteic. In each experiment, 30 cows were used and separated into three groups. In experiment 1, there were no differences in dry matter intake (DMI), milk yield (MY), or apparent total tract digestibility (aTTd) among the three diets, but milk fat content increased with increasing forage proportion, even though the similar neutral detergent fiber of all diets. Nitrogen use efficiency was highest in the diet containing 600 g forage/kg DM, and some evidence was observed for a better profitability with this forage proportion. In experiment 2, feeding legumes increased DMI despite no effects on aTTd. Milk yield increased in line with DMI, with a larger increase for the fresh cowpea. Nitrogen use efficiency and milk composition were not affected by the diets. The increased MY and lower feed costs increased the economic benefits when feeding legumes, particularly when feeding fresh cowpea. Feeding fresh cowpea or jackbean silage to dairy cows appears to be an alternative to soybean as protein source, ideally at a forage proportions of 600 g/kg DM, without altering milk yield and quality and increasing the farm profitability.

Potential role of ATP-binding cassette transporters against acaricides in the brown dog tick Rhipicephalus sanguineus sensu lato.

ATP-binding cassette (ABC) transporters have been shown to be involved in pesticide detoxification in arthropod vectors and are thought to contribute to the development of drug resistance. Little is currently known about the role they play in ticks, which are among the more important vectors of human and animal pathogens. Here, the role of ABC transporters in the transport of fipronil and ivermectin acaricides in the tick Rhipicephalus sanguineus (Ixodida: Ixodidae) was investigated. Larvae were treated with acaricide alone and acaricide in combination with a sub-lethal dose of the ABC transporter inhibitor cyclosporine A. The LC50 doses and 95% confidence intervals (CIs) estimated by mortality data using probit analysis were 67.930 p.p.m. (95% CI 53.780-90.861) for fipronil and 3741 p.p.m. (95% CI 2857-4647) for ivermectin. The pre-exposure of larvae to a sub-lethal dose of cyclosporine A reduced the LC50 dose of fipronil to 4.808 p.p.m. (95% CI 0.715-9.527) and that of ivermectin to 167 p.p.m. (95% CI 15-449), which increased toxicity by about 14- and 22-fold, respectively. The comparison of mortality data for each separate acaricide concentration showed the synergic effect of cyclosporine A to be reduced at higher concentrations of acaricide. These results show for the first time a strong association between ABC transporters and acaricide detoxification in R.sanguineus s.l.

Atividade in vitro do extrato hidroalcoólico de Lippia sidoides Cham sobre larvas de terceiro estádio de nematódeos gastrintestinais (família Trichostrongylidae) de caprinos / In vitro activity of the hydroalcoholic extract of Lippia sidoides Cham on buoyant larvae of third-stage gastrointestinal nematodes (family Trichostrongylidae) of goats

Avaliou-se in vitro a atividade larvicida do extrato hidroalcóolico de alecrim pimenta (Lippia sidoides Cham) sobre larvas de terceiro estádio de nematoides gastrintestinais de caprinos. Os resultados encontrados demonstraram que a concentração de 500 mg mL-1 apresentou atividade efetiva e com capacidade de ação de 95,89%, demonstrando desta forma a possibilidade do uso terapêutico anti-helmíntico para esse extrato.

The in vitro larvicidal activity of the hydroalcoholic extract of rosemary pepper (Lippia sidoides Cham) was evaluated on buoyant larvae of third-stage gastrointestinal gastrointestinal nematodes of goats. The results demonstrated that the concentration of 500 mg mL-1 presented effective activity, with a capacity of action of 95.89%, thus demonstrating the possibility of anthelmintic therapeutic use for this extract.

Avaliação in vitro do extrato hidroalcoólico (EHA) de alecrim pimenta (Lippia sidoides Cham. ) sobre o desenvolvimento de ovos de nematódeos gastrointestinais (Trichostrongylidae) / In vitro evaluation of alecrim pimenta (Lippia sidoides Cham. ) hydroalcoholic extract (HAE) on the development of gastrointestinal nematode (Trichostrongylidae) eggs

Atualmente a fito medicina vem sendo usada no controle de diversas doenças parasitárias particularmente as parasitoses gastrointestinais. Objetivou-se com este estudo avaliar a eficácia do extrato hidroalcoólico (EHA) de Lippia sidoides Cham sobre o desenvolvimento de ovos de nematódeos gastrointestinais. O efeito ovicida foi determinado através de análise probabilística, modelo logístico, utilizados os softwares R versão 2.2.1 e EPI6. Foram obtidos ovos embrionados em fezes de cabras naturalmente infectadas com nematóides Trichostrongylidae e o número de ovos fecais foi determinado usando-se a técnica modificada de McMaster. Cinquenta μL da suspensão contendo 40 ovos foram transferidas a placas de poliestireno e incubadas com 12 concentrações diferentes do EHA sendo avaliada durante 72 horas a temperatura ambiente. Os resultados demonstraram diferentes eficácias para o fito medicamento com menor taxa de desenvolvimento de ovos na concentração de 500 mg mL-1 . Conclui-se que o EHA pode ter papel importante sobre o desenvolvimento in vitro de ovos de nematóides gastrintestinais, revelando atividade ovicida.

Phytomedicine has been currently used in the control of several parasitic diseases, particularly gastrointestinal ones. The aim of this study was to evaluate the efficacy of the hydroalcoholic extract (HAE) from Lippia sidoides Cham. on the development of gastrointestinal nematode eggs. The ovicidal effect was determined through probabilistic analysis, logistic model, by using the programs R version 2.2.1 and Epi InfoTM 6. Embryonated eggs were obtained from feces of goats naturally infected with Trichostrongylidae nematodes and the fecal egg count was determined by using the modified McMaster technique. Fifty microliters of the suspension containing 40 eggs were transferred to polystyrene plates and incubated with 12 different HAE concentrations, and evaluations were performed during 72h at room temperature. The results demonstrated different efficacy of extracts, with lower egg development rate at 500 mg mL-1. In conclusion, HAE may play an important role on the in vitro development of gastrointestinal nematode eggs, indicating ovicidal activity.

Molecular detection of anaplasma platys in a naturally-infected cat in Brazil

Following the accidental finding of inclusion bodies similar to Anaplasma platys in a stained blood smear from a cat, DNA analysis of the 16S rRNA gene was performed and 100 percent identity was found with different strains of A. platys. These data confirm that cats are susceptible to parasitism by A. platys.

Molecular detection of Anaplasma platys in a naturally-infected cat in Brazil.

Following the accidental finding of inclusion bodies similar to Anaplasma platys in a stained blood smear from a cat, DNA analysis of the 16S rRNA gene was performed and 100% identity was found with different strains of A. platys. These data confirm that cats are susceptible to parasitism by A. platys.

Estándares e indicadores para evaluar la atención de enfermería en unidades psiquiátricas / standard and indicators to evaluate the attention of nursing in psychiatric units

El estándar es una declaración explícita de calidad, para determinar su grado de cumplimiento es necesario contar con indicadores, determinando el margen entre el desempeño ideal y el real en los procesos y los resultados de satisfacción de los usuarios. La medición de la calidad de la atención de enfermería es tan importante como extensa, las unidades psiquiátricas no pueden estar ajenas a esto; siendo que la salud mental es factor importante para el desarrollo progresivo y armónico de la sociedad, la inexistencia de estándares e indicadores atenta contra la salud física del paciente, el equilibrio emocional del trabajador, la economía familiar del enfermo y los gastos de la institución; en este sentido se validaron instrumentos con enfoque de sistema, que se sirvan de guía para evaluar la atención de enfermería en unidades psiquiátricas, a través de procedimientos específicos de enfermería: baño de regadera, alimentación y ministración de medicamentos por vía oral y descanso y sueño; utilizando la Técnica Delphi y Alpha de Cronbach, demostrando que éstos permitirán planear acciones eficientes y eficaces que mejoren la atención de enfermería en psiquiatría, luego que obtuvieron la confiabilidad necesaria para ser utilizados a nivel nacional y ser referentes a nivel internacional.

The standard is an explicit declaration of quality, to determine its execution degree it is necessary to have indicators, determining the margin between the ideal acting and the real one in the processes and the results of the users' satisfaction. The mensuration of the quality of the nursing attention is as important as extensive, the psychiatric units cannot be unaware to this; being that the mental health is important factor for the progressive and harmonic development of the society, the nonexistence of standard and indicators attempt against the patient's physical health, the worker's emotional balance, the sick person family economy and the expenses of the institution; in this sense instruments were validated with focus of system that you/they are served as guide to evaluate the nursing attention in psychiatric units, through specific procedures of nursing: watering-can bathroom, feeding and ministración of medications for by oral route and I rest and dream; using the Technical Delphi and Alpha of Cronbach, demonstrating that these will allow efficient and effective actions that improve the nursing attention in psychiatry, to drift then that they obtained the necessary dependability to be used at national level and to be relating at international level.

[Isolated trigeminal neuropathy associated with a fatty tumor of Meckel's cavum]. / Neuropatía aislada del nervio trigémino asociada a tumor graso en el cavum de Meckel.

INTRODUCTION: In recent years there has been increasing interest in isolated trigeminal sensory neuropathy. We present a case with an unusual association of this neuropathy and a fatty tumour of Meckel's cavum. CLINICAL CASE: A 24 year old man consulted for occasional episodes (during the previous two months) of dysesthesia of the right maxillary region. These were self-limiting and lasted only a few minutes. There was no lacrimation, apparent trigger factor, conjunctival injection or reduction in level of consciousness. There were no abnormal findings either on general or on full neurological examination. On cranial CT there was no signal from the tip of the right petrous temporal bone, but no space-occupying lesion nor pathological uptake of contrast material. On cranial MR there was an extra-axial lesion in the superior part of the tip of the right petrous temporal bone of 2 x 2 cm, localized to Meckel's cavum and right cavernous sinus, with a small lobule in the right lateral part of the prepontine cisterna. CONCLUSIONS: Trigeminal sensory neuropathy has been described in association with different connective tissue disorders, infections of the central nervous system, vascular dilatations and very varied types of tumours, particularly meningioma. The commonest site for lesions related to this clinical condition is the posterior fossa. A tumour in Meckel's cavum is rarely found in relation to this diagnosis, and from our review of the literature, involvement of fatty tumours seems to be rare.

Dysfunctional glucocorticoid receptor with a single point mutation ablates the CCAAT/enhancer binding protein-dependent growth suppression response in a steroid-resistant rat hepatoma cell variant.

We used glucocorticoid-resistant and -sensitive hepatoma cell variants to characterize the mechanism of hepatoma cell resistance to the growth inhibitory effects of glucocorticoids. BDS1 hepatoma cells express transcriptionally active glucocorticoid receptors and undergo a stringent G1 cell cycle arrest in response to glucocorticoids that is dependent on the induced expression of the CCAAT/enhancer binding protein alpha (C/EBPalpha) transcription factor. In contrast, EDR1 hepatoma cells, which express normal levels of glucocorticoid receptors, fail to growth arrest or express C/EBPalpha when treated with glucocorticoids. Ectopic expression of wild-type rat glucocorticoid receptors into EDR1 cells restored the growth suppression response, suggesting a defect in the EDR1 receptor. DNA sequence analysis revealed a single point mutation causing a cysteine-to-tyrosine substitution at amino acid position 457 (C457Y-GR) in the zinc finger region of the glucocorticoid receptor that mediates both receptor-DNA and receptor-protein interactions. Glucocorticoid activation of the alpha1-acid glycoprotein (AGP) promoter, a liver acute-phase response gene, requires receptor-DNA binding as well as an interaction with C/EBPalpha. In contrast to the wild-type glucocorticoid receptor, ectopic expression of C/EBPalpha in EDR1 cells, or coexpression of C/EBPalpha along with the C457Y-GR into receptor-deficient EDR3 cells was required to partially restore glucocorticoid responsiveness of the AGP promoter by the EDR1 glucocorticoid receptor. Constitutive expression of the wild-type glucocorticoid receptor, but not the C457Y-GR mutant, was sufficient to restore the glucocorticoid growth suppression response to receptor-deficient EDR3 cells. Thus, we have identified a glucocorticoid-resistant hepatoma cell variant with a single point mutation in the zinc finger region of the glucocorticoid receptor gene that ablates the glucocorticoid growth suppression response and attenuates transcriptional activation of the AGP promoter.

[Carotidynia as a form of presentation of paraxysmal hemicrania]. / Carotidinia como forma de presentación de la hemicránea paroxística.

INTRODUCTION: Paroxysmal hemicrania is a well-defined clinical condition about which many articles have been published. Attempts have been made to explain the response of this illness to indomethacin, suggesting its possible cervical origin. In some patients it is set off by stimulation of certain trigger zones situated in this region. The exceptional radiation of the pain seen in our patient clearly supports this theory. CLINICAL CASE: A 34 year old man with a past history of a similar but briefer episode 5 years previously presented to us. He complained of repeated episodes of stabbing pain with no obvious cause. The pain started at the base of the neck and radiated along the right carotid vessels to the cheek, base of the nose and ipsilateral eye. This was accompanied by injection of the conjunctivae, tears, nasal congestion and nasal discharge. Each episode lasted 15 to 30 minutes and was repeated 20 to 25 times a day without any particular relation to the time of day. The neurological examination, MR and angio-MR were normal. Before being seen by us he had been treated with prednisone and verpamil without effect. Indomethacin at a dose of 100 mg/day controlled the problem completely. CONCLUSIONS: We report a case of paroxysmal hemicrania with a spontaneous description of pain starting at the base of the neck and radiating along the carotid vessels. We consider this clinical description to be of interest since it supports the theories of a cervicogenic origin of this type of headache.

Role of the CCAAT/enhancer binding protein-alpha transcription factor in the glucocorticoid stimulation of p21waf1/cip1 gene promoter activity in growth-arrested rat hepatoma cells.

The preceding paper (Cha, H. H., Cram, E. J., Wang, E. C., Huang, A. J., Kasler, H. G., and Firestone, G. L. (1998) J. Biol. Chem. 273, 0000-0000(478563) defined a glucocorticoid responsive region within teh promoter of the p21 CDK inhibitor gene that contains a putative DNA-binding site for the transcription factor CCAAT/ enhancer binding protein-alpha (C/EBP alpha). Wild type rat BDS1 hepatoma cells as well as as4 hepatoma cells, which express antisense sequences to C/EBP alpha and ablate its protein production, were utilized to investigate the role of this transcription factor in the glucocorticoid regulation of p21 gene expression. The stimulation of p21 protein levels and promoter activity, as well as inhibition of CDK2-mediated retinoblastoma protein phosphorylation, by the synthetic glucocorticoid, dexamethasone, required the expression of C/EBP alpha. Overexpression of C/EBP alpha in as4 cells rescued the dexamethasone responsiveness of the p21 promoter. Site-directed mutagenesis of the p21 promoter revealed that dexamethasone stimulation of p21 promoter activity required the C/EBP consensus DNA-binding site. Furthermore, in glucocorticoid receptor-defective EDR1 hepatoma cells, dexamethasone failed to stimulate C/EBP alpha and p21 protein expression and promoter activities. Our results have established a functional link between the glucocorticoid receptor signaling pathway that mediates a G1 cell cycle arrest of rat hepatoma cells and the transcriptional control of p21 by a cascade that requires the steroid induction of C/EBP alpha gene expression.

Glucocorticoid-stimulated CCAAT/enhancer-binding protein alpha expression is required for steroid-induced G1 cell cycle arrest of minimal-deviation rat hepatoma cells.

By genetic correlation with the growth-suppressible phenotype and direct functional tests, we demonstrate that the glucocorticoid-stimulated expression of the CCAAT/enhancer-binding protein alpha (C/EBP alpha) transcription factor is required for the steroid-mediated G1 cell cycle arrest of minimal-deviation rat hepatoma cells. Comparison of C/EBP alpha transcript and active protein levels induced by the synthetic glucocorticoid dexamethasone in glucocorticoid growth-suppressible (BDS1), nonsuppressible receptor-positive (EDR1) and nonsuppressible receptor-deficient (EDR3) hepatoma cell proliferative variants revealed that the stimulation of C/EBP alpha expression is a rapid, glucocorticoid receptor-mediated response associated with the G1 cell cycle arrest. Consistent with the role of C/EBP alpha as a critical intermediate in the growth suppression response, maximal induction of transcription factor mRNA occurred within 2 h of dexamethasone treatment whereas maximal inhibition of [3H] thymidine incorporation was observed 24 h after steroid treatment. As a direct functional approach, ablation of C/EBP alpha protein expression and DNA-binding activity by transfection of an antisense C/EBP alpha expression vector blocked the dexamethasone-induced G1 cell cycle arrest of hepatoma cells but did not alter general glucocorticoid responsiveness. Transforming growth factor beta induced a G1 cell cycle arrest in C/EBP alpha antisense transfected cells, demonstrating the specific involvement of C/EBP alpha in the glucocorticoid growth suppression response. Constitutive expression of a conditionally activated form of C/EBP alpha caused a G1 cell cycle arrest of BDS1 hepatoma cells in the absence of glucocorticoids. In contrast, overexpression of C/EBP beta or C/EBP delta had no effect on hepatoma cell growth. Taken together, these results demonstrate that the steroid-induced expression of C/EBP alpha is necessary to mediate the glucocorticoid G1 cell cycle arrest of rat hepatoma cells and implicates a role for this transcription factor in the growth control of liver-derived epithelial tumor cells.

Early events in tissues during infection with pathogenic (SIVmac239) and nonpathogenic (SIVmac1A11) molecular clones of simian immunodeficiency virus.

The extent of virus replication, tissue distribution, localization of virus within tissues, and the presence of pathological lesions was examined early after experimental infection of rhesus monkeys with simian immunodeficiency virus (SIV). Three strains of SIV were used: molecularly cloned pathogenic SIVmac239; molecularly cloned nonpathogenic SIVmac1A11; and uncloned pathogenic SIVmac. The major targets of infection in all animals at 2 weeks postinoculation were the thymus and spleen. The distribution of virus within lymphoid organs varied with the viral inoculum: nonpathogenic SIVmac1A11 was present primarily within lymphoid follicles and in the thymic cortex; SIVmac239 was present primarily within periarteriolar lymphoid sheaths in the spleen, the paracortex of lymph nodes, and the medulla of the thymus; uncloned SIVmac was present in all these areas but tended to parallel the distribution of SIVmac239. Animals inoculated with nonpathogenic SIVmac1A11 had fewer SIV-positive cells by in situ hybridization and after 13 weeks postinoculation, virus was undetectable in any tissue from these animals. No significant pathological abnormalities were recognized in animals inoculated with this nonpathogenic virus. In contrast, nearly half of the animals inoculated with either SIVmac or SIVmac239 developed significant pathological lesions, including opportunistic infections by 13 weeks postinoculation, highlighting the virulence of these viruses. Our results indicate marked differences in tissue distribution between pathogenic and nonpathogenic molecular clones of SIV during the acute phase of infection. The most striking differences were the absence of SIVmac1A11 from the central nervous system and thymic medulla. The prominent early involvement of the thymus suggests that infection of this organ is a key event in the induction of immune suppression by SIV.

[Environmental isolation of Vibrio cholerae 01 in continental waters of the Province of Seville]. / Aislamiento ambiental de Vibrio cholerae 01 en aguas continentales de la provincia de Sevilla.

BACKGROUND: Many bibliographical references suggest reserves of Vibrio cholerae in the aquatic world, strains of both the serovariety no 01 and 01 having been isolated in different parts of the globe in fresh and extensive salt waters. METHODS: Samples were taken monthly from January to May and from October to December, and every fortnight from June to September. The method of isolation applied is in accordance with the standard set down by the Institute of Health Carlos III, with some specific modifications. RESULTS: During the period 90/91, routine analyses carried out by the Andalusian Service of Health of waters from the area of the Continental Basin in the province of Seville showed the presence of Vibrio cholerae 01. In the same way, during the complete annual cycle Vibrio cholerae no 01 was also isolated. CONCLUSIONS: These isolations did not coincide with outbreaks or individual cases of cholera, so the authors, in agreement with what is described in the bibliography, consider that Vibrio cholerae no 01 forms a part of certain aquatic environments, which is in direct relation to environmental isolations of the serovariety 01.

Viral determinants of simian immunodeficiency virus (SIV) virulence in rhesus macaques assessed by using attenuated and pathogenic molecular clones of SIVmac.

To identify viral determinants of simian immunodeficiency virus (SIV) virulence, two pairs of reciprocal recombinants constructed from a pathogenic (SIVmac239) and a nonpathogenic (SIVmac1A11) molecular clone of SIV were tested in rhesus macaques. A large 6.2-kb fragment containing gag, pol, env, and the regulatory genes from each of the cloned (parental) viruses was exchanged to produce one pair of recombinant viruses (designated SIVmac1A11/239gag-env/1A11 and SIVmac239/1A11gag-env/239 to indicate the genetic origins of the 5'/internal/3' regions, respectively, of the virus). A smaller 1.4-kb fragment containing the external env domain of each of the parental viruses was exchanged to create the second pair (SIVmac1A11/239env/1A11 and SIVmac239/1A11env/239) of recombinant viruses. Each of the two parental and four recombinant viruses was inoculated intravenously into four rhesus macaques, and all 24 animals were viremic by 4 weeks postinoculation (p.i.). Virus could not be isolated from peripheral blood mononuclear cells (PBMC) of any animals infected with SIVmac1A11 after 6 weeks p.i. but was consistently isolated from all macaques inoculated with SIVmac239 for 92 weeks p.i. Virus isolation was variable from animals infected with recombinant viruses; SIVmac1A11/239gag-env/1A11 and SIVmac239/1A11env/239 were isolated most frequently. Animals inoculated with SIVmac239 had 10 to 100 times more virus-infected PBMC than those infected with recombinant viruses. Three animals infected with SIVmac239 died with simian AIDS (SAIDS) during the 2-year observation period after inoculation, and the fourth SIVmac239-infected animal had clinical signs of SAIDS. Two animals infected with recombinant viruses died with SAIDS; one was infected with SIVmac239/1A11gag-env/239, and the other was infected with SIVmac1A11/239gag-env/1A11. The remaining 18 macaques remained healthy by 2 years p.i., and 13 were aviremic. One year after inoculation, peripheral lymph nodes of some of these healthy, aviremic animals harbored infected cells. All animals seroconverted within the first few weeks of infection, and the magnitude of antibody response to SIV was proportional to the levels and duration of viremia. Virus-suppressive PBMC were detected within 2 to 4 weeks p.i. in all animals but tended to decline as viremia disappeared. There was no association of levels of cell-mediated virus-suppressive activity and either virus load or disease progression. Taken together, these results indicate that differences in more than one region of the viral genome are responsible for the lack of virulence of SIVmac1A11.