RESUMEN

Global cerebral ischemia induces selective acute neuronal injury of the CA1 region of the hippocampus. The type of cell death that ensues may include different programmed cell death mechanisms namely apoptosis and necroptosis, a recently described type of programmed necrosis. We investigated whether necroptosis contributes to hippocampal neuronal death following oxygen-glucose deprivation (OGD), an in vitro model of global ischemia. We observed that OGD induced a death receptor (DR)-dependent component of necroptotic cell death in primary cultures of hippocampal neurons. Additionally, we found that this ischemic challenge upregulated the receptor-interacting protein kinase 3 (RIP3) mRNA and protein levels, with a concomitant increase of the RIP1 protein. Together, these two related proteins form the necrosome, the complex responsible for induction of necroptotic cell death. Interestingly, we found that caspase-8 mRNA, a known negative regulator of necroptosis, was transiently decreased following OGD. Importantly, we observed that the OGD-induced increase in the RIP3 protein was paralleled in an in vivo model of transient global cerebral ischemia, specifically in the CA1 area of the hippocampus. Moreover, we show that the induction of endogenous RIP3 protein levels influenced neuronal toxicity since we found that RIP3 knock-down (KD) abrogated the component of OGD-induced necrotic neuronal death while RIP3 overexpression exacerbated neuronal death following OGD. Overexpression of RIP1 also had deleterious effects following the OGD challenge. Taken together, our results highlight that cerebral ischemia activates transcriptional changes that lead to an increase in the endogenous RIP3 protein level which might contribute to the formation of the necrosome complex and to the subsequent component of necroptotic neuronal death that follows ischemic injury.

Asunto(s)

Apoptosis/fisiología , Isquemia Encefálica/patología , Hipocampo/patología , Hipoxia/metabolismo , Neuronas/patología , Proteína Serina-Treonina Quinasas de Interacción con Receptores/metabolismo , Regulación hacia Arriba/fisiología , Animales , Anticuerpos/farmacología , Apoptosis/efectos de los fármacos , Isquemia Encefálica/metabolismo , Células Cultivadas , Modelos Animales de Enfermedad , Maleato de Dizocilpina/farmacología , Embrión de Mamíferos , Glucosa/deficiencia , Hipocampo/citología , Hipoxia/patología , Imidazoles/farmacología , Indoles/farmacología , L-Lactato Deshidrogenasa/metabolismo , Neuronas/efectos de los fármacos , Fármacos Neuroprotectores/farmacología , Ratas , Ratas Sprague-Dawley , Proteína Serina-Treonina Quinasas de Interacción con Receptores/genética , Factor de Necrosis Tumoral alfa/inmunología , Factor de Necrosis Tumoral alfa/metabolismo , Regulación hacia Arriba/efectos de los fármacos

RESUMEN

Human respiratory syncytial virus (HRSV) is an important cause of respiratory disease. The majority of studies addressing the importance of virus co-infections to the HRSV-disease have been based on the detection of HRSV by RT-PCR, which may not distinguish current replication from prolonged shedding of remnant RNA from previous HRSV infections. To assess whether co-detections of other common respiratory viruses are associated with increased severity of HRSV illnesses from patients who were shedding viable-HRSV, nasopharyngeal aspirates from children younger than 5 years who sought medical care for respiratory infections in Ribeirão Preto (Brazil) were tested for HRSV by immunofluorescence, RT-PCR and virus isolation in cell culture. All samples with viable-HRSV were tested further by PCR for other respiratory viruses. HRSV-disease severity was assessed by a clinical score scale. A total of 266 samples from 247 children were collected and 111 (42%) were HRSV-positive. HRSV was isolated from 70 (63%), and 52 (74%) of them were positive for at least one additional virus. HRSV-positive diseases were more severe than HRSV-negative ones, but there was no difference in disease severity between patients with viable-HRSV and those HRSV-positives by RT-PCR. Co-detection of other viruses did not correlate with increased disease severity. HRSV isolation in cell culture does not seem to be superior to RT-PCR to distinguish infections associated with HRSV replication in studies of clinical impact of HRSV. A high rate of co-detection of other respiratory viruses was found in samples with viable-HRSV, but this was not associated with more severe HRSV infection.

Asunto(s)

Coinfección/virología , Virus ARN/aislamiento & purificación , Infecciones del Sistema Respiratorio/virología , Virosis/virología , Brasil , Preescolar , Coinfección/patología , Femenino , Técnica del Anticuerpo Fluorescente , Humanos , Lactante , Recién Nacido , Masculino , Nasofaringe/virología , Infecciones del Sistema Respiratorio/patología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Índice de Severidad de la Enfermedad , Cultivo de Virus , Virosis/patología

RESUMEN

External cervical resorption (ECR) is a sequela of dentoalveolar trauma that may cause functional, esthetic, and psychologic alterations. The aim of this study was to report a successful multidisciplinary treatment approach performed in a 12-year-old patient who presented with posttraumatic ECR associated with extensive opened cavity, pulp necrosis, and periapical lesion of tooth number 9, with an initial unfavorable prognosis. Crown lengthening was done to enable restoration of vestibular surface with resin composite, forming a barrier that allowed endodontic treatment. Afterwards, a prefabricated fiberglass post was cemented and esthetic restoration was performed using the adhesive technique and direct composite veneer. Reconstructive periodontal surgery was performed to correct irregular gingival contour. After treatment and successive follow-up sessions, it was concluded that although the tooth had been indicated for extraction, low invasive direct techniques were effective to recover function and esthetics and to maintain the tooth in the oral cavity.

Asunto(s)

Incisivo/lesiones , Grupo de Atención al Paciente , Resorción Radicular/terapia , Niño , Resinas Compuestas/química , Alargamiento de Corona/métodos , Caries Dental/complicaciones , Materiales Dentales/química , Necrosis de la Pulpa Dental/complicaciones , Restauración Dental Permanente/métodos , Coronas con Frente Estético , Estética Dental , Femenino , Estudios de Seguimiento , Gingivoplastia/métodos , Vidrio/química , Humanos , Planificación de Atención al Paciente , Enfermedades Periapicales/complicaciones , Técnica de Perno Muñón/instrumentación , Tratamiento del Conducto Radicular/métodos , Fracturas de los Dientes/complicaciones , Resultado del Tratamiento

RESUMEN

The GluA4-containing Ca(2+)-permeable α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid receptors (Ca-AMPARs) were previously shown to mediate excitotoxicity through mechanisms involving the activator protein-1 (AP-1), a c-Jun N-terminal kinase (JNK) substrate. To further investigate JNK involvement in excitotoxic pathways coupled to Ca-AMPARs we used HEK293 cells expressing GluA4-containing Ca-AMPARs (HEK-GluA4). Cell death induced by overstimulation of Ca-AMPARs was mediated, at least in part, by JNK. Importantly, JNK activation downstream of these receptors was dependent on the extracellular Ca(2+) concentration. In our quest for a molecular link between Ca-AMPARs and the JNK pathway we found that the JNK interacting protein-1 (JIP-1) interacts with the GluA4 subunit of AMPARs through the N-terminal domain. In vivo, the excitotoxin kainate promoted the association between GluA4 and JIP-1 in the rat hippocampus. Taken together, our results show that the JNK pathway is activated by Ca-AMPARs upon excitotoxic stimulation and suggest that JIP-1 may contribute to the propagation of the excitotoxic signal.

Asunto(s)

Proteínas Adaptadoras Transductoras de Señales/metabolismo , Calcio/metabolismo , Activación Enzimática/fisiología , MAP Quinasa Quinasa 4/metabolismo , Receptores AMPA/metabolismo , Transducción de Señal/fisiología , Animales , Western Blotting , Electroforesis en Gel de Poliacrilamida , Activación Enzimática/efectos de los fármacos , Agonistas de Aminoácidos Excitadores/farmacología , Células HEK293 , Humanos , Inmunoprecipitación , Ácido Kaínico/farmacología , Masculino , Ratas , Ratas Wistar , Receptores AMPA/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Transfección

RESUMEN

Imipenem-resistant Pseudomonas aeruginosa is a leading cause of hospital-acquired pneumonia. Aiming to determine the risk factors associated for hospital-acquired pneumonia due to imipenem-resistant Pseudomonas aeruginosa, we undertook a retrospective case-case-control study. Patients admitted to a 14-bed medical-surgical intensive care unit from a university-affiliated hospital with hospital-acquired pneumonia caused by imipenem-resistant Pseudomonas aeruginosa strains and by imipenem-susceptible Pseudomonas aeruginosa strains were matched to control patients by time under risk and comorbidities. A total of 58 resistant cases, 47 susceptible cases and 237 controls were evaluated. The risk factors independently associated to hospital-acquired pneumonia caused by imipenem-resistant Pseudomonas aeruginosa were: duration of hospitalisation, Acute Physiological and Chronic Health Evaluation II score, male gender receipt of haemodialysis, receipt of piperacillin-tazobactam and receipt of third-generation cephalosporins.

Asunto(s)

Antibacterianos/farmacología , Infección Hospitalaria/etiología , Imipenem/farmacología , Unidades de Cuidados Intensivos , Neumonía Bacteriana/etiología , Infecciones por Pseudomonas/microbiología , Pseudomonas aeruginosa/efectos de los fármacos , Estudios de Casos y Controles , Infección Hospitalaria/microbiología , Farmacorresistencia Bacteriana , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neumonía Bacteriana/microbiología , Factores de Riesgo

RESUMEN

Cells preferentially expressing GluR4-containing alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) receptors are particularly sensitive to excitotoxicity mediated through non-N-methyl-D-aspartate receptors. However, the excitotoxic signalling pathways associated with GluR4-containing AMPA receptors are not known. In this work, we investigated the downstream signals coupled to excitotoxicity mediated by Ca2+-permeable GluR4-containing AMPA receptors, using a HEK 293 cell line constitutively expressing the GluR4flip subunit of AMPA receptors (HEK-GluR4). Glutamate stimulation of GluR4-containing AMPA receptors decreased cell viability, in a calcium-dependent manner, when the receptor desensitisation was prevented with cyclothiazide. The excitotoxic stimulation mediated through GluR4-containing AMPA receptors increased activator protein-1 (AP-1) DNA-binding activity. Inhibition of the AP-1 activity by overexpression of a c-Jun dominant-negative form protected HEK-GluR4 cells against excitotoxic damage. Taken together, the results indicate that overactivation of Ca2+-permeable GluR4-containing AMPA receptors is coupled to a death pathway mediated, at least in part, by the AP-1 transcription factor.

Asunto(s)

Calcio/metabolismo , Aminoácidos Excitadores/toxicidad , Ácido Glutámico/toxicidad , Receptores AMPA/metabolismo , Factor de Transcripción AP-1/metabolismo , 6-Ciano 7-nitroquinoxalina 2,3-diona/farmacología , Benzotiadiazinas/farmacología , Línea Celular , Supervivencia Celular/efectos de los fármacos , ADN/metabolismo , Relación Dosis-Respuesta a Droga , Antagonistas de Aminoácidos Excitadores/farmacología , Humanos , Subunidades de Proteína , Receptores AMPA/efectos de los fármacos , Receptores AMPA/genética , Transducción de Señal/efectos de los fármacos , Factores de Tiempo

RESUMEN

The aim of this work was to investigate whether excitotoxicity induced by overstimulation of different ionotropic glutamate receptors could trigger different intracellular signaling cascades. Cultured chick neuronal retina cells, essentially amacrine-like, were particularly sensitive to the toxicity induced by non-NMDA glutamate receptor agonists. One hour stimulation with 100 microM kainate induced a reduction of cell viability of about 44%, as assessed by the MTT test 24 hr after stimulation. Kainate-induced toxicity was mediated through AMPA receptors. Glutamate (100 microM, 1 hr) reduced cell viability by 26%, essentially acting through N-methyl-D-aspartate receptors. Five hours after stimulation, neuronal retina cells had an apoptotic-like nuclear morphology. In retinal neurons, the excitotoxic stimulation, with either glutamate or kainate, induced a calcium-dependent enhancement of the DNA-binding activity of the activating protein-1 (AP-1) transcription factor, which was maximal 2 hr after stimulation. Glutamate induced a greater increase in the AP-1 DNA-binding activity than did kainate. Supershift assays using antibodies directed against different members of the Fos and Jun protein families showed that the AP-1 complex in retinal neurons includes proteins of the Fos family, namely, Fra-2, c-Jun, and Jun D. The DNA-binding activity of the nuclear factor-kappaB transcription factor was not significantly changed upon excitotoxic stimulation with any agonist. Stimulation of glutamate receptors with 100 microM kainate or 100 microM glutamate for 2 min was sufficient to induce the activation of the extracellular signal-regulated kinase (ERK). Inhibition of the ERK activation with the MEK inhibitors U 0126 and PD 98059 increased the toxicity induced by kainate but was without effect on the toxicity induced by glutamate. These results indicate that, although stimulation with both glutamate receptor agonists increased ERK phosphorylation, only kainate-induced ERK activation correlates with the activation of a survival signaling pathway. Our results suggest that, in chick embryo retinal neurons, the signaling pathways that mediate excitotoxic cell death and neuroprotection are stimulus specific.

Asunto(s)

Células Amacrinas/metabolismo , Apoptosis/fisiología , Agonistas de Aminoácidos Excitadores/farmacología , Sistema de Señalización de MAP Quinasas/fisiología , Neurotoxinas/farmacología , Receptores de Glutamato/metabolismo , Factores de Transcripción/metabolismo , Células Amacrinas/efectos de los fármacos , Células Amacrinas/embriología , Animales , Apoptosis/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/fisiología , Células Cultivadas/efectos de los fármacos , Células Cultivadas/metabolismo , Embrión de Pollo , Inhibidores Enzimáticos/farmacología , Antagonistas de Aminoácidos Excitadores/farmacología , Ácido Glutámico/metabolismo , Ácido Glutámico/farmacología , Ácido Kaínico/farmacología , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Proteínas Quinasas Activadas por Mitógenos/antagonistas & inhibidores , Proteínas Quinasas Activadas por Mitógenos/metabolismo , FN-kappa B/efectos de los fármacos , FN-kappa B/metabolismo , Receptores AMPA/agonistas , Receptores AMPA/antagonistas & inhibidores , Receptores AMPA/metabolismo , Receptores de Glutamato/efectos de los fármacos , Receptores de N-Metil-D-Aspartato/agonistas , Receptores de N-Metil-D-Aspartato/antagonistas & inhibidores , Receptores de N-Metil-D-Aspartato/metabolismo , Factor de Transcripción AP-1/efectos de los fármacos , Factor de Transcripción AP-1/metabolismo , Factores de Transcripción/efectos de los fármacos

RESUMEN

The epidermal proteins from staged Apis mellifera pupae and pharate adults and the progress of cuticular pigmentation until adult eclosion were used as parameters to study integument differentiation under hormonal treatment. Groups of bees were treated at the beginning of the pupal stage with the juvenile hormone analog pyriproxyfen (PPN) or as pharate adults with 20-hydroxyecdysone (20E). Another group was treated with both hormones applied successively at these same developmental periods. Controls were maintained without treatment. The epidermal proteins, separated by SDS-PAGE and identified by silver staining, were studied at seven intervals during the pupal and pharate adult stages. The initiation and progress of cuticular pigmentation was also monitored and compared to controls. The results showed that PPN reduced the interval of expression of some epidermal proteins, whereas 20E had an antagonistic effect, promoting a prolongation in the time of expression of the same proteins. In PPN-treated bees, cuticular pigmentation started precociously, whereas in 20E-treated individuals this developmental event was postponed. The double hormonal treatment restored the normal progress of cuticular pigmentation and, to a large extent, the temporal epidermal protein pattern. These results are discussed in relation to the 20E titer modulation and morphogenetic hormone interaction.

RESUMEN

The interactions of sulfonated chloroaluminum phthalocyanine (AlPcSn) with human low-density lipoproteins (LDL) were studied in vitro in human plasma and in an isolated LDL fraction, in order to understand the potential effects of the sensitizer against LDL. The AlPcSn added to plasma distributes in all lipoproteins as observed by the drastic color changes of the separated fractions by ultracentrifugation. In isolated LDL, incubation with AlPcSn causes fluorescence quenching of the apoprotein tryptophan residues. Furthermore, AlPcSn incorporates in liposomes, with a lipid composition similar to the external monolayer of human LDL, as indicated by absorbance spectroscopy. The photosensitizing properties of AlPcSn in LDL particles were studied on the basis of the fluorescence quenching of previously incorporated cis-parinaric acid (PnA), used as an oxidation probe, and of O2 consumption. The photooxidation of either PnA or LDL lipids is highly dependent on irradiation time and on the dye concentration. Moreover, photooxidation of LDL proceeds only during the illumination period. After stopping the illumination and upon addition of Cu2+ to the LDL solution, the oxidative rate is resumed, probably due to hydroperoxide cleavage and formation of species able to propagate the oxidative reaction. Thus, our data indicate that AlPcSn distributes in human plasma lipoproteins and, in isolated LDL, it can interact either with the lipid phase or the apoprotein. The photooxidation of LDL induced by AlPcSn seems to involve singlet oxygen as the main reactive species in the degradative process.

Asunto(s)

Indoles/sangre , Lipoproteínas LDL/sangre , Lipoproteínas LDL/metabolismo , Compuestos Organometálicos/sangre , Fármacos Fotosensibilizantes/sangre , Humanos , Unión Proteica , Espectrometría de Fluorescencia

RESUMEN

BACKGROUND: The development of new small guiding catheters with large internal lumen has allowed their use in routine coronary angioplasty. OBJECTIVES: The aim of this study is to present the technical characteristics, results and complication rates obtained with the use of 6 French guiding catheters compared with those obtained with the use of 8 French. METHODS: During a 23 month period, a total of 355 consecutive patients was enrolled in this study. Coronary angioplasty was performed in 177 of them using a 6F guiding catheter and 178 using an 8F. RESULTS: We found no differences in technical characteristics between both groups: Radiation time (15.7 +/- 14 min vs 16.2 +/- 14 min), guiding catheter to patient ratio (1.1 +/- 0.3 vs 1.06 +/- 0.2), number of balloon catheters per patient (1.2 +/- 0.7 vs 1.36 +/- 0.7). There were no differences in the results obtained (Success 93% in 6F group vs 91% in 8F), major complication rates (Death 0.5% vs 1.6%, CABG 1.1% vs 2.2% or AMI 0% vs 2.2%), or peripheral complications. CONCLUSIONS: In coronary angioplasty, with the use of 6F guiding catheters the same results can be achieved as with the use of larger catheters without an increase in technical difficulties or in complication rates.

Asunto(s)

Angioplastia Coronaria con Balón/instrumentación , Cateterismo Cardíaco , Anciano , Diseño de Equipo , Femenino , Humanos , Masculino , Persona de Mediana Edad

RESUMEN

In this study we determined the changes in the intracellular free Ca2+ concentration, associated with the inhibitory modulation of the exocytotic release of GABA by GABAB receptor activation in rat cerebrocortical synaptosomes. We observed that SK&F 97541 and (-)baclofen both act as agonists of the presynaptic GABAB receptors in modulating GABA release and Ca2+ influx due to KCl (10 mM) depolarization, but SK&F 97541 is more potent than (-)baclofen in modulating both Ca2+ influx and GABA release. Thus, activation of GABAB receptors by either SK&F97541 (10 microM) or by (-)baclofen (100 microM) caused about 18% inhibition of the increase in [Ca2+]i, due to KCl depolarization, and inhibited the [3H]GABA release by about 30%. The pharmacological similarities of the GABAB receptor activation in producing inhibition of both calcium channel mediated influx of Ca2+ and transmitter release suggest that presynaptic inhibition of GABA release by GABAB receptor activation may result, at least in part, from inhibition of Ca2+ influx through P-type (or possibly Q-type) Ca2+ channels, sensitive to omega-Agatoxin IVA (200 nM). Furthermore, modulation of GABA release of GABAB receptors was abolished by preincubation with pertussis toxin, suggesting that a pertussis toxin sensitive G protein may be the coupling factor between GABAB receptors and the voltage-dependent Ca2+ channels associated with the exocytotic release of GABA in rat cerebrocortical nerve terminals.

Asunto(s)

Calcio/metabolismo , Corteza Cerebral/metabolismo , Terminales Presinápticos/metabolismo , Receptores de GABA-B/metabolismo , Sinaptosomas/metabolismo , Ácido gamma-Aminobutírico/metabolismo , Animales , Canales de Calcio/metabolismo , Electrofisiología , Agonistas del GABA/farmacología , Membranas Intracelulares/metabolismo , Concentración Osmolar , Toxina del Pertussis , Potasio/farmacología , Ratas , Ratas Wistar , Sinaptosomas/efectos de los fármacos , Sinaptosomas/fisiología , Factores de Virulencia de Bordetella/farmacología

RESUMEN

O objetivo das equipes volantes de Saúde é dar atendimento a populaçäo da zona rural do Município de Säo Paulo. A equipe volante é constituída por um médico, um auxiliar de enfermagem, um atendente de enfermagem e um motorista, sendo o transporte da mesma efetuado por veículo tipo furgäo que leva também vacinas, medicamentos, suplemento alimentar, material e prontuários necessários ao atendimento. Os locais de atendimento säo fixos, indicados e cedidos pela comunidade, obedecendo a uma frequência semanal de 1 até 3 vezes por semana, de acordo com a demanda. Esse projeto foi implantado em dezembro de 1980 e vem sendo avaliado continuamente

Asunto(s)

Grupo de Atención al Paciente , Estrategias de Salud Locales , Salud Rural , Brasil