Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 282
Filtrar
Mais filtros

Intervalo de ano de publicação
1.
J Insect Sci ; 22(3)2022 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-35596588

RESUMO

The expansion of Integrated Pest Management (IPM), including biological control, has had several positive consequences for the agricultural environment and participants in the production chain. To enable successful operation and applications of biological control, production of insects used for rearing natural enemies (parasitoids and predators) must be optimized to reduce time and costs and improve production both qualitatively and quantitatively. The present study evaluated the effect of wheat varieties, the main component of artificial diets for Ephestia kuehniella, on the reproductive performance and biological parameters of this flour moth, which is used for mass production of Trichogramma spp. (Hymenoptera: Trichogrammatidae) and other parasitoids and predators. Four varieties of wheat were compared: BRS 327, BRS Marcante, BRS Parrudo, and KBR, with and without the addition of corn E. kuehniella reared on 97% BRS 327 wheat flour + 3% nutritional yeast had the best biological parameters and substitution of corn for about half of the wheat increased the number of eggs per female.


Assuntos
Himenópteros , Mariposas , Animais , Dieta , Feminino , Farinha , Humanos , Óvulo , Triticum , Zea mays
2.
Int J Cosmet Sci ; 43(1): 11-19, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32886359

RESUMO

OBJECTIVE: Product aesthetics and sensory performance can strongly influence a cosmetic product's acceptance by consumers. However, classic sensory analysis is time-consuming, expensive and does not provide information on the target group's preference. In the previous phase of this project, we had untrained consumers evaluate six cosmetic emulsions based on their aesthetics using a check-all-that-apply (CATA) survey. In this project, our goals were to quantitatively characterize the rheology and textural properties of the six cosmetic emulsions containing green, bio-derived emollients and identify statistical relationships between the consumers' description of products and the instrumental measurements. METHODS: Six emulsions were prepared-three with olive oil and three with heptyl undecylenate as an emollient. Four sensory-like attributes, namely firmness, work of shear, stickiness and adhesiveness, were tested using a texture analyser. Rheological characterization included continuous flow testing and oscillatory measurements. Droplet size and stability were also evaluated. Statistical relationships were quantified between measurements in this study and sensory survey results published previously. RESULTS: The textural and rheological results indicated that the emulsions were different-as designed. The texture and rheology measurements had analogous grouping outcomes to the consumers' discrimination. Emulsions 1 and 2 were the firmest, hardest to spread, stickiest and had the highest viscosity, while Emulsions 5 and 6 were the least firm, easiest to spread, less sticky than Emulsions 1 and 2, and had the lowest viscosity. Emulsions 3 and 4 fell in between the other two groups. Using olive oil instead of heptyl undecylenate as an emollient increased firmness, spreading, stickiness, viscosity and droplet size of the emulsions in every case-when comparing emulsions within each pair. All six emulsions had a shear-thinning behaviour. Viscosity and firmness directly correlated for the emulsions. Emulsions were visually stable at room temperature over the course of 6 months and viscosity remained relatively constant over this period also. CONCLUSION: Certain sensory attributes can be reliably predicted with instrumental measurements. Identifying and quantifying sensory-texture-rheology relationships can contribute to achieving appropriate product characteristics tailored to suit market needs.


Assuntos
Cosméticos/química , Emolientes/química , Percepção , Reologia , Química Verde
3.
Acta Neurol Scand ; 136(3): 212-216, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28032330

RESUMO

OBJECTIVES: Cerebrospinal fluid (CSF) from some patients with amyotrophic lateral sclerosis (ALS) has been demonstrated to significantly reduce the neuronal viability of primary cell cultures of motor neurons. We aimed to study the potential clinical consequences associated with the cytotoxicity of CSF in a cohort of patients with ALS. METHODS: We collected CSF from thirty-one patients with ALS. We analysed cytotoxicity by incubating it into the primary cultures of motor cortex neurons. Neural viability was quantified after 24 hours using the colorimetric MTT reduction assay. All patients were followed up from the moment of diagnosis to death, and a complete evaluation during disease progression and survival was performed, including gastrostomy and respiratory assistance. RESULTS: Twenty-one patients (67.7%) presented a cytotoxic CSF. There were no significant differences between patients with and without cytotoxicity regarding mean time from symptom onset to the diagnosis, from the diagnosis to death, from the diagnosis to respiratory assistance with BIPAP, from diagnosis to gastrostomy and from the onset of symptoms to death. In Cox regression analysis, bulbar onset, but not cytotoxicity, gender or age at onset, was associated with a lower risk of survival. CONCLUSIONS: Cerebrospinal fluid cytotoxicity was not associated with differential survival rates. This suggests that the presence of cytotoxicity in CSF, measured through neuronal viability in primary cultures of motor cortex neurons, could reflect different mechanisms of the disease, but it does not predict disease outcome.


Assuntos
Esclerose Lateral Amiotrófica/líquido cefalorraquidiano , Líquido Cefalorraquidiano/metabolismo , Neurônios Motores/metabolismo , Adulto , Idoso , Esclerose Lateral Amiotrófica/metabolismo , Esclerose Lateral Amiotrófica/patologia , Biomarcadores/líquido cefalorraquidiano , Células Cultivadas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neurônios Motores/patologia
4.
Chaos ; 24(2): 024404, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24985458

RESUMO

Many sleep centres try to perform a reduced portable test in order to decrease the number of overnight polysomnographies that are expensive, time-consuming, and disturbing. With some limitations, heart rate variability (HRV) has been useful in this task. The aim of this investigation was to evaluate if inclusion of symbolic dynamics variables to a logistic regression model integrating clinical and physical variables, can improve the detection of subjects for further polysomnographies. To our knowledge, this is the first contribution that innovates in that strategy. A group of 133 patients has been referred to the sleep center for suspected sleep apnea. Clinical assessment of the patients consisted of a sleep related questionnaire and a physical examination. The clinical variables related to apnea and selected in the statistical model were age (p < 10(-3)), neck circumference (p < 10(-3)), score on a questionnaire scale intended to quantify daytime sleepiness (p < 10(-3)), and intensity of snoring (p < 10(-3)). The validation of this model demonstrated an increase in classification performance when a variable based on non-linear dynamics of HRV (p < 0.01) was used additionally to the other variables. For diagnostic rule based only on clinical and physical variables, the corresponding area under the receiver operating characteristic (ROC) curve was 0.907 (95% confidence interval (CI) = 0.848, 0.967), (sensitivity 87.10% and specificity 80%). For the model including the average of a symbolic dynamic variable, the area under the ROC curve was increased to 0.941 (95% = 0.897, 0.985), (sensitivity 88.71% and specificity 82.86%). In conclusion, symbolic dynamics, coupled with significant clinical and physical variables can help to prioritize polysomnographies in patients with a high probability of apnea. In addition, the processing of the HRV is a well established low cost and robust technique.


Assuntos
Frequência Cardíaca/fisiologia , Apneia Obstrutiva do Sono/diagnóstico , Apneia Obstrutiva do Sono/fisiopatologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Intervalos de Confiança , Bases de Dados como Assunto , Eletrocardiografia , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Dinâmica não Linear , Curva ROC , Apneia Obstrutiva do Sono/diagnóstico por imagem , Inquéritos e Questionários , Ultrassonografia , Adulto Jovem
5.
Neurologia ; 29(6): 346-52, 2014.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-24144827

RESUMO

INTRODUCTION: The neurotoxic effects of cerebrospinal fluid (CSF) from patients with amyotrophic lateral sclerosis (ALS) have been reported by various authors who have attributed this neurotoxicity to the glutamate in CSF-ALS. MATERIAL AND METHODS: Cultures of rat embryonic cortical neurons were exposed to CSF from ALS patients during an incubation period of 24 hours. Optical microscopy was used to compare cellular changes to those elicited by exposure to 100µm glutamate, and confocal microscopy was used to evaluate immunohistochemistry for caspase-3, TNFα, and peripherin. RESULTS: In the culture exposed to CSF-ALS, we observed cells with nuclear fragmentation and scarce or null structural modifications to the cytoplasmic organelles or to plasma membrane maintenance. This did not occur in the culture exposed to glutamate. The culture exposed to CSF-ALS also demonstrated increases in caspase-3, TNFα, and in peripherin co-locating with caspase-3, but not with TNFα, suggesting that TNFα may play an early role in the process of apoptosis. CONCLUSIONS: CFS-ALS cytotoxicity is not related to glutamate. It initially affects the nucleus without altering the cytoplasmic membrane. It causes cytoplasmic apoptosis that involves an increase in caspase-3 co-located with peripherin, which is also overexpressed.


Assuntos
Esclerose Lateral Amiotrófica/líquido cefalorraquidiano , Líquido Cefalorraquidiano/metabolismo , Ácido Glutâmico/farmacologia , Neurônios Motores/efeitos dos fármacos , Animais , Células Cultivadas , Líquido Cefalorraquidiano/química , Citotoxinas/farmacologia , Humanos , Neurônios Motores/citologia , Neurônios Motores/metabolismo , Ratos
6.
J Food Prot ; 85(7): 1044-1052, 2022 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-35512125

RESUMO

ABSTRACT: Tomatoes (Solanum lycopersicum) are one of the most commonly consumed fruits worldwide. The fruit can become contaminated with Salmonella and Listeria monocytogenes at various stages of the production and supply chain, and these pathogens may survive under various storage conditions. The effects of relative humidity, temperature, and duration of storage on the attachment and survival of both pathogens on the surface of tomatoes were investigated. Fresh whole Roma tomatoes were inoculated with a cocktail of Salmonella or L. monocytogenes strains and stored at 5, 12, 25, 30, or 35°C for up to 10 days. Every day during storage, relative humidity and temperature were measured and tomatoes were removed to enumerate pathogens cells that were loosely attached (LA; cells were detached from the tomato surface by rinsing) and strongly attached (SA; sonication was required to detach cells from the tomato surface). The attachment strength (SR) was calculated to express the proportion of surviving SA cells on the tomato surface. The initial levels of Salmonella and L. monocytogenes on the tomato surface after inoculation were 6.6 and 6.5 log CFU per tomato for LA cells and 5.1 and 5.6 log CFU per tomato for SA cells, respectively. For both pathogens, the LA levels were higher (P < 0.05) than the SA levels. The LA and SA levels differed significantly as a function of temperature, relative humidity, and duration of storage. The SR for Salmonella was affected by storage time but not temperature, whereas the SR for L. monocytogenes was affected by storage time and temperature and relative humidity (P < 0.05). An understanding of the attachment and survival of Salmonella and L. monocytogenes on tomatoes stored under various temperature conditions may be useful for preventing or reducing the establishment of pathogens and for designing improved decontamination methods.


Assuntos
Listeria monocytogenes , Salmonella enterica , Solanum lycopersicum , Contagem de Colônia Microbiana , Microbiologia de Alimentos , Umidade , Salmonella , Temperatura
7.
Am J Physiol Cell Physiol ; 300(3): C610-23, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21160033

RESUMO

Modulation of high-threshold voltage-dependent calcium channels by neurotransmitters has been the subject of numerous studies in cultures of neurons and chromaffin cells. However, no studies on such modulation exist in chromaffin cells in their natural environment, the intact adrenal medullary tissue. Here we performed such a study in voltage-clamped chromaffin cells of freshly prepared mouse adrenal slices under the whole cell configuration of the patch-clamp technique. The subcomponents of the whole cell inward Ca(2+) current (I(Ca)) accounted for 49% for L-, 28% for N-, and 36% for P/Q-type channels. T-type Ca(2+) channels or residual R-type Ca(2+) currents were not seen. However, under the perforated-patch configuration, 20% of I(Ca) accounted for a toxin-resistant R-type Ca(2+) current. Exogenously applied ATP and methionine-enkephalin (Met-enk) inhibited I(Ca) by 33%. Stop-flow and Ca(2+) replacement by Ba(2+), which favored the release of endogenous ATP and opioids, also inhibited I(Ca), with no changes in activation or inactivation kinetics. This inhibition was partially voltage independent and insensitive to prepulse facilitation. Furthermore, in about half of the cells, suramin and naloxone augmented I(Ca) in the absence of exogenous application of ATP/Met-enk. No additional modulation of I(Ca) was obtained after bath application of exogenous ATP and opioids to these already inhibited cells. Augmentation of I(Ca) was also seen upon intracellular dialysis of guanosine 5'-[ß-thio]diphosphate (GDPßS), indicating the existence in the intact slice of a tonic inhibition of I(Ca) in resting conditions. These results suggest that in the intact adrenal tissue a tonic inhibition of I(Ca) exists, mediated by purinergic and opiate receptors.


Assuntos
Trifosfato de Adenosina/metabolismo , Medula Suprarrenal/metabolismo , Canais de Cálcio/metabolismo , Membrana Celular/metabolismo , Células Cromafins/metabolismo , Peptídeos Opioides/metabolismo , Trifosfato de Adenosina/farmacologia , Medula Suprarrenal/efeitos dos fármacos , Animais , Bário/farmacologia , Cálcio/metabolismo , Cálcio/farmacologia , Membrana Celular/efeitos dos fármacos , Células Cromafins/efeitos dos fármacos , Encefalina Metionina/metabolismo , Encefalina Metionina/farmacologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Inibição Neural/efeitos dos fármacos , Inibição Neural/fisiologia , Peptídeos Opioides/farmacologia , Técnicas de Cultura de Órgãos
8.
Eur J Neurosci ; 33(1): 69-81, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21091801

RESUMO

We investigated the effects of muscarinic acetylcholine receptor (mAChR) activation on GABAergic synaptic transmission in rat hippocampal neurons. Current-clamp recordings revealed that methacholine produced membrane depolarization and action potential firing. Methacholine augmented the bicuculline-sensitive and GABA(A) -mediated frequency of spontaneous inhibitory postsynaptic currents (sIPSCs); the action of methacholine had a slow onset and longer duration. The increase in methacholine-evoked sIPSCs was completely inhibited by atropine and was insensitive to glutamatergic receptor blockers. Interestingly, methacholine action was not inhibited by intracellular perfusion with GDP-ß-S, suggesting that muscarinic effects on membrane excitability and sIPSC frequency are mainly presynaptic. McN-A-343 and pirenzepine, selective agonist and antagonist of the m1 mAChR subtype, respectively, neither enhanced sIPSCs nor inhibited the methacholine effect. However, the m3-m5 mAChR antagonist 4-DAMP, and the m2-m4 mAChR antagonist himbacine inhibited the methacholine effect. U73122, an IP(3) production inhibitor, and 2APB, an IP(3) receptor blocker, drastically decreased the methacholine effect. Recording of miniature events revealed that besides the effect exerted by methacholine on membrane firing properties and sIPSC frequency, muscarinic receptors also enhanced the frequency of mIPSCs with no effect on their amplitude, possibly modulating the molecular machinery subserving vesicle docking and fusion and suggesting a tight colocalization at the active zone of the presynaptic terminals. These data strongly suggest that by activating presynaptic m2, m3, m4 and m5 mAChRs, methacholine can increase membrane excitability and enhance efficiency in the GABA release machinery, perhaps through a mechanism involving the release of calcium from the endoplasmic reticulum.


Assuntos
Hipocampo/citologia , Neurônios/fisiologia , Isoformas de Proteínas/metabolismo , Receptores Muscarínicos/metabolismo , Receptores Pré-Sinápticos/metabolismo , Potenciais Sinápticos/fisiologia , Ácido gama-Aminobutírico/metabolismo , Potenciais de Ação/fisiologia , Animais , Células Cultivadas , Antagonistas de Aminoácidos Excitatórios/farmacologia , Feminino , Hipocampo/fisiologia , Inositol 1,4,5-Trifosfato/metabolismo , Receptores de Inositol 1,4,5-Trifosfato/metabolismo , Cloreto de Metacolina/farmacologia , Agonistas Muscarínicos/farmacologia , Antagonistas Muscarínicos/farmacologia , Neurônios/citologia , Neurônios/efeitos dos fármacos , Técnicas de Patch-Clamp , Fosfatidilinositol 3-Quinases/metabolismo , Gravidez , Ratos , Ratos Sprague-Dawley , Receptores Nicotínicos/metabolismo , Potenciais Sinápticos/efeitos dos fármacos , Transmissão Sináptica/efeitos dos fármacos , Transmissão Sináptica/fisiologia
9.
Nat Cell Biol ; 2(2): 57-61, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10655583

RESUMO

Activation of calcium-ion (Ca2+) channels on the plasma membrane and on intracellular Ca2+ stores, such as the endoplasmic reticulum, generates local transient increases in the cytosolic Ca2+ concentration that induce Ca2+ uptake by neighbouring mitochondria. Here, by using mitochondrially targeted aequorin proteins with different Ca2+ affinities, we show that half of the chromaffin-cell mitochondria exhibit surprisingly rapid millimolar Ca2+ transients upon stimulation of cells with acetylcholine, caffeine or high concentrations of potassium ions. Our results show a tight functional coupling of voltage-dependent Ca2+ channels on the plasma membrane, ryanodine receptors on the endoplasmic reticulum, and mitochondria. Cell stimulation generates localized Ca2+ transients, with Ca2+ concentrations above 20-40 microM, at these functional units. Protonophores abolish mitochondrial Ca2+ uptake and increase stimulated secretion of catecholamines by three- to fivefold. These results indicate that mitochondria modulate secretion by controlling the availability of Ca2+ for exocytosis.


Assuntos
Medula Suprarrenal/metabolismo , Sinalização do Cálcio , Cálcio/metabolismo , Células Cromafins/metabolismo , Mitocôndrias/metabolismo , Acetilcolina/farmacologia , Medula Suprarrenal/citologia , Animais , Transporte Biológico , Cafeína/farmacologia , Canais de Cálcio , Carbonil Cianeto m-Clorofenil Hidrazona/farmacologia , Catecolaminas/metabolismo , Bovinos , Membrana Celular/metabolismo , Células Cromafins/citologia , Clonazepam/análogos & derivados , Clonazepam/farmacologia , Retículo Endoplasmático/metabolismo , Potássio/farmacologia , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Trocador de Sódio e Cálcio/antagonistas & inibidores , Tiazepinas/farmacologia
10.
Osteoarthritis Cartilage ; 18 Suppl 1: S24-7, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20399898

RESUMO

The antiinflammatory and antiapoptotic effects of chondroitin sulfate (CS) are being used to treat osteoarthritis. Recent evidence has revealed that those peripheral effects of CS may also have therapeutic interest in diseases of the central nervous system (CNS). We review here such evidence. Perineuronal nets (PNNs) formed by chondroitin sulfate proteoglycans (CSPGs) may have a neuroprotective action against oxidative stress potentially involved in neurodegeneration. On the other hand, in human neuroblastoma SH-SY5Y cells CS has antioxidant and neuroprotective effects by activating the signaling pathway PKC/PI3K/Akt and inducing the antioxidant enzyme hemoxygenase-1. Consistent with this is the observation that protein kinase C (PKC) blockade overcomes inhibition of neurite outgrowth elicited by CSPGs. In addition, CS protects cortical neurons against excytotoxic death by phosphorylation of intracellular signals and the suppression of caspase-3 activation. Of interest is the finding that a disaccharide derived from CSPG degradation (CSGP-DS) protects neurons against toxicity both in vitro and in vivo. Furthermore, CSGP-DS efficiently protects against neuronal loss in experimental autoimmune encephalomyelitis and uveitis, decreases secretion of tumor necrosis factor-alpha (TNF-alpha) and block necrosis factor kappa B (NF-kappaB) translocation. In conclusion, CS may have neuroprotective properties linked to its antioxidant and antiinflammatory effects.


Assuntos
Anti-Inflamatórios/uso terapêutico , Antioxidantes/uso terapêutico , Proteoglicanas de Sulfatos de Condroitina/uso terapêutico , Sulfatos de Condroitina/uso terapêutico , Fármacos Neuroprotetores/uso terapêutico , Animais , Humanos , Doenças Neurodegenerativas/prevenção & controle , Plasticidade Neuronal/efeitos dos fármacos
11.
Neotrop Entomol ; 49(2): 250-257, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31797306

RESUMO

Huanglongbing (HLB), the most destructive citrus disease worldwide, was first recorded in Brazil in 2004, and since then, more than 50 million trees identified with this disease have been eliminated. The disease is managed mainly by controlling the psyllid vector Diaphorina citri Kuwayama, 1908 (Hemiptera: Liviidae). Although the presence of the insect in commercial citrus groves is low, HLB infection rates increase in areas bordering the groves. The disease is transmitted by psyllids from host citrus plants in areas outside the managed groves, such as abandoned or organic groves and residential trees, and from orange jasmine plants in urban settings. In order to provide information to support HLB control, this study evaluated the biotic and abiotic variables that affect the dynamics of D. citri populations after releases of the parasitoid wasp Tamarixia radiata (Waterston, 1922) (Hymenoptera: Eulophidae) in external sources of HLB inocula. The study was divided into two parts. After releasing the parasitoids in non-commercial areas, we determined the following: (a) the variables that significantly affected the number of nymphs collected on shoots in the same non-commercial area; (b) the variables that significantly affected the number of adult psyllids collected in a neighboring commercial citrus area. Our results indicated that the number of nymphs in external areas was affected only by the host plant and rainfall. However, periodic parasitoid releases significantly reduced the number of adult psyllids collected in the commercial area. The results indicate that the release of parasitoids in external sources of inocula has the potential to maximize actions for D. citri control, contributing to the reduction of psyllid populations in commercial areas. Consequently, this strategy may help to manage the disease infection without an increase in insecticide use.


Assuntos
Hemípteros/parasitologia , Controle Biológico de Vetores , Vespas/fisiologia , Animais , Brasil , Citrus , Hemípteros/microbiologia , Doenças das Plantas/microbiologia
12.
J Chromatogr A ; 1616: 460784, 2020 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-31864726

RESUMO

Micellar liquid chromatography (MLC) is a reversed-phase mode with mobile phases containing an organic solvent and a micellised surfactant. Most procedures developed in MLC are implemented in the isocratic mode, since the general elution problem in chromatography is less troublesome. However, gradient elution may be still useful in MLC to analyse mixtures of compounds within a wide range of polarities, in shorter times. MLC using gradients is attractive to determine by direct injection moderate to low polar compounds in physiological samples. In these analyses, the use of initial micellar conditions (isocratic or gradient) with a fixed amount of surfactant above the critical micellar concentration, keeping the organic solvent content low, will provide better protection of the column against the precipitation of the proteins in the physiological fluid. Once the proteins are swept away, the elution strength can be increased using a positive gradient of organic solvent to reduce the analysis time. This may give rise to the transition from the micellar to the submicellar mode, since micelles are destroyed at sufficiently high concentration of organic solvent. In this work, several retention models covering extended solvent domains in MLC are developed and tested, and applied to investigate the performance in isocratic, linear and multi-linear gradient separations. The study was applied to the screening of ß-adrenoceptor antagonists in urine samples, using mobile phases prepared with sodium dodecyl sulphate and 1-propanol. Predicted chromatograms were highly accurate in all situations, although suffered of baseline problems and minor shifts for peaks eluting close to a steep gradient segment. Two columns (C18 and C8) were investigated, with the C8 column being preferable owing to the smaller amount of adsorbed surfactant.


Assuntos
Técnicas de Química Analítica/métodos , Cromatografia Líquida , Micelas , Solventes/química , 1-Propanol/química , Antagonistas Adrenérgicos beta/análise , Antagonistas Adrenérgicos beta/urina , Adsorção , Humanos , Indicadores e Reagentes , Dodecilsulfato de Sódio/química , Tensoativos/química
13.
Iran J Vet Res ; 21(2): 92-96, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32849886

RESUMO

BACKGROUND: Analgesic and hemodynamic effects of ketamine in subanesthetic doses during surgical anesthesia and postoperative, are due to the action on the N-methyl-D-aspartate receptors (NMDAR). AIMS: To evaluate the intraoperative cardiorespiratory effects provided by ketamine compared to lidocaine, both administered epidurally, in bitches submitted to ovariohysterectomy. METHODS: Thirty-six dogs of different breeds were used in a randomized, prospective, and blinded clinical trial. Two groups were formed: GKET (ketamine 3 mg/kg, n=18) and GLIDO (lidocaine 4 mg/kg, n=18). Animals were premedicated with acepromazine 0.05 mg/kg intravenous. Anesthesia was induced with propofol 5 mg/kg intravenous. Anesthetic maintenance was performed with isoflurane in 100% oxygen. Every 5 min during surgery, heart rate (HR), respiratory rate (RR), esophageal temperature (°C), oxygen saturation (SPO2), end tidal carbon dioxide (ETCO2) and mean arterial pressure (MAP) were monitored. RESULTS: Cardiorespiratory variables during anesthesia were within normal ranges. Heart rate was significantly higher at 5 (108 ± 12 vs 95 ± 11) and 10 (110 ± 11 vs 97 ± 11) min in GKET compared to GLIDO after the start of surgery (P=0.03 and P=0.01, respectively). Mean arterial pressure was higher in GKET, (100 ± 23, 105 ± 35, and 103 ± 35 mmHg) in comparison with GLIDO (66 ± 7, 74 ± 10, and 67 ± 9 mmHg) at 20, 25 and 30 min (P=0.01, P=0.004, and P=0.002, respectively). Mild hypothermia at 25 (36.5 1.3C) and 30 (36.5 1.4C) min in the GKET was recorded. CONCLUSION: Epidural administration of ketamine provides better hemodynamic stability, compared to the use of epidural lidocaine.

14.
J Cell Biol ; 144(2): 241-54, 1999 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-9922451

RESUMO

The presence and physiological role of Ca2+-induced Ca2+ release (CICR) in nonmuscle excitable cells has been investigated only indirectly through measurements of cytosolic [Ca2+] ([Ca2+]c). Using targeted aequorin, we have directly monitored [Ca2+] changes inside the ER ([Ca2+]ER) in bovine adrenal chromaffin cells. Ca2+ entry induced by cell depolarization triggered a transient Ca2+ release from the ER that was highly dependent on [Ca2+]ER and sensitized by low concentrations of caffeine. Caffeine-induced Ca2+ release was quantal in nature due to modulation by [Ca2+]ER. Whereas caffeine released essentially all the Ca2+ from the ER, inositol 1,4, 5-trisphosphate (InsP3)- producing agonists released only 60-80%. Both InsP3 and caffeine emptied completely the ER in digitonin-permeabilized cells whereas cyclic ADP-ribose had no effect. Ryanodine induced permanent emptying of the Ca2+ stores in a use-dependent manner after activation by caffeine. Fast confocal [Ca2+]c measurements showed that the wave of [Ca2+]c induced by 100-ms depolarizing pulses in voltage-clamped cells was delayed and reduced in intensity in ryanodine-treated cells. Our results indicate that the ER of chromaffin cells behaves mostly as a single homogeneous thapsigargin-sensitive Ca2+ pool that can release Ca2+ both via InsP3 receptors or CICR.


Assuntos
Cálcio/metabolismo , Células Cromafins/metabolismo , Retículo Endoplasmático/metabolismo , Equorina , Animais , Cafeína/farmacologia , Bloqueadores dos Canais de Cálcio/farmacologia , Bovinos , Células Cromafins/efeitos dos fármacos , Histamina/farmacologia , Microscopia Confocal , Rianodina/farmacologia , Tapsigargina/farmacologia
15.
Rev Gastroenterol Mex (Engl Ed) ; 84(4): 427-433, 2019.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-30292584

RESUMO

INTRODUCTION AND OBJECTIVE: Eosinophilic esophagitis is a chronic, immune-mediated disease described in case series and publications worldwide. Over the past twenty years, the authors of different studies have attempted to evaluate its incidence and prevalence. The objetive of the present study was to estimate the prevalence of eosinophilic esophagitis in a group of children seen at 36 pediatric gastroenterology centers in ten Latin American countries. MATERIALS AND METHODS: A multicenter, observational, and cross-sectional study was conducted that estimated the period prevalence of eosinophilic esophagitis in children seen at outpatient consultation and that underwent diagnostic upper gastrointestinal endoscopy for any indication at 36 centers in 10 Latin American countries, within a 3-month time frame. RESULTS: Between April and June 2016, 108 cases of eosinophilic esophagitis were evaluated. Likewise, an average of 29,253 outpatient consultations and 4,152 diagnostic upper gastrointestinal endoscopies were carried out at the 36 participating centers. The period prevalence of eosinophilic esophagitis in the population studied (n=29,253) was 3.69 cases×1,000 (95% CI: 3.04 to 4.44), and among the children that underwent routine upper gastrointestinal endoscopy (n=4,152), it was 26x1,000 (95% CI: 22.6 to 29.4). CONCLUSIONS: The general period prevalence of eosinophilic esophagitis in a group of children evaluated at 36 Latin American pediatric gastroenterology centers was 3.69×1,000, and in the children that underwent endoscopy, it was 26×1,000. There was important prevalence variability between the participating countries and centers. The present analysis is the first study conducted on the prevalence of pediatric eosinophilic esophagitis in Latin America.


Assuntos
Esofagite Eosinofílica/epidemiologia , Adolescente , Criança , Pré-Escolar , Estudos Transversais , Feminino , Gastroenterologia , Hospitais Especializados , Humanos , Lactente , América Latina/epidemiologia , Masculino , Prevalência
16.
Eur J Neurosci ; 27(5): 1097-110, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18312591

RESUMO

The role of postsynaptic nicotinic receptors for acetylcholine (nAChRs) in mediating fast neurotransmission processes in the CNS is controversial. Here we have studied the modulation of synaptic transmission by an agonist (choline) and an allosteric modulator (5-OH-indole) of alpha7 nAChRs in rat hippocampal neuronal cultures. Choline evoked a fast inactivating inward current, causing neuron depolarization and action potential discharge, thereby enhancing the spontaneous postsynaptic current activity (sPSCs). This effect was markedly enhanced when both choline and 5-OH-indole were applied together and was blocked by the selective alpha7 nAChR antagonist methyllycaconitine. This choline action was suppressed by the GABA(A) receptor antagonist bicuculline, while the glutamatergic receptor antagonist kynurenic acid had no effect. Frequency, but not amplitude or area, of both excitatory and inhibitory miniature postsynaptic currents (mEPSCs and mIPSCs) were drastically reduced when Ca(2+) influx was blocked by Cd(2+). Additionally, nAChR activation did not modify the mIPSCs. These data suggest that Ca(2+) influx through the highly Ca(2+)-permeablealpha7 nAChRs was insufficient to directly activate neurotransmitter release, suggesting that a tight colocalization of this receptor with secretory hot spots is unlikely. In a few cases, the activation of alpha7 AChRs led to a suppression of spontaneous synaptic transmission. This effect may be related to the potentiation of GABAergic interneurons that inhibit the spontaneous activity of neurons making synapses with the cell under study. We suggest that GABA release is modulated by alpha7 nAChRs. Thus, selective allosteric modulators of alpha7 nAChRs could have potential therapeutic applications in brain disorders such as epilepsy and schizophrenia and in alterations of cognition and sensory processing.


Assuntos
Hipocampo/fisiologia , Interneurônios/fisiologia , Receptores Nicotínicos/fisiologia , Transmissão Sináptica/fisiologia , Ácido gama-Aminobutírico/fisiologia , Regulação Alostérica/efeitos dos fármacos , Regulação Alostérica/fisiologia , Animais , Células Cultivadas , Feminino , Antagonistas GABAérgicos/farmacologia , Hipocampo/efeitos dos fármacos , Interneurônios/efeitos dos fármacos , Gravidez , Ratos , Ratos Sprague-Dawley , Transmissão Sináptica/efeitos dos fármacos , Receptor Nicotínico de Acetilcolina alfa7
17.
Int J Oral Maxillofac Surg ; 37(1): 1-7, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17822881

RESUMO

This literature review was performed to analyse the outcomes of clinical studies of alveolar distraction osteogenesis (DO) listed by PUBMED between January 1996 and December 2006. A PUBMED search identified 128 articles on alveolar DO. Twenty articles covering 209 cases were analysed, considering location, device and procedural parameters, rate of augmentation, aspect of final implant placement and follow up. The mean latency period was 7.26+/-2.31 days, distraction rate 0.71+/-0.27 mm/day, rate of augmentation 6.88+/-2.52 mm and consolidation period 12.22+/-5.58 weeks. A total of 469 implants were placed and followed post loading for an average of 14.19+/-11.03 months, with a survival rate of 97%. Of the different procedural parameters, only the difference between mean consolidation period for failed (8.10+/-2.51 weeks) and successful (12.43+/-5.62 weeks) implants was statistically significant (P=0.01). Use of DO may be advantageous in terms of the success rate of implants placed in augmented sites, but there is still a lack of sufficient data based on long-term follow up. Future experimental studies should evaluate the application of different methods with a view to shortening the overall treatment period and improving the performance of implants placed in distracted alveolar ridges.


Assuntos
Processo Alveolar/cirurgia , Implantação Dentária Endóssea/métodos , Falha de Restauração Dentária , Osteogênese por Distração/métodos , Humanos , Fatores de Tempo , Resultado do Tratamento
18.
J Econ Entomol ; 111(1): 120-126, 2018 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-29267899

RESUMO

The fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), cannot survive prolonged periods of freezing temperatures, thereby limiting where it can overwinter in North America. Climate change is anticipated to reduce the frequency of freeze days in Florida over the decades, with the potential consequence of a significant expansion of the overwintering range, whose northern limit in North America was assessed between 27 and 28°N in the last century. To assess this possibility, the development of the fall armyworm on corn leaves, one of the main host plants in the United States, was determined at five constant temperatures ranging from 14 to 30°C. Based on the development time, the thermal constant and the lower threshold temperature were used to estimate the number of generations of fall armyworm at 42 locations in the state of Florida, from 2006 to 2016. Maps were constructed to provide a visual description of the interpolated data, using GIS (Geographic Information System). The highest number of generations was observed in the counties farther south, an area that showed the highest temperatures during the years and plays a strategic role in maintaining fall armyworm populations in corn fields. Additionally, we conclude that in the absence of freeze periods, the northern limit for fall armyworm overwintering should be between 28 and 29°N.


Assuntos
Mudança Climática , Cadeia Alimentar , Spodoptera/crescimento & desenvolvimento , Zea mays , Animais , Florida , Larva/crescimento & desenvolvimento , Estações do Ano , Temperatura , Zea mays/crescimento & desenvolvimento
19.
Neurologia (Engl Ed) ; 33(4): 211-223, 2018 May.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-27570180

RESUMO

INTRODUCTION: Cerebrospinal fluid (CSF) from amyotrophic lateral sclerosis (ALS) patients induces cytotoxic effects in in vitro cultured motor neurons. MATERIAL AND METHODS: We selected CSF with previously reported cytotoxic effects from 32 ALS patients. Twenty-eight adult male rats were intracerebroventricularly implanted with osmotic mini-pumps and divided into 3 groups: 9 rats injected with CSF from non-ALS patients, 15 rats injected with cytotoxic ALS-CSF, and 4 rats injected with a physiological saline solution. CSF was intracerebroventricularly and continuously infused for periods of 20 or 43days after implantation. We conducted clinical assessments and electromyographic examinations, and histological analyses were conducted in rats euthanised 20, 45, and 82days after surgery. RESULTS: Immunohistochemical studies revealed tissue damage with similar characteristics to those found in the sporadic forms of ALS, such as overexpression of cystatinC, transferrin, and TDP-43 protein in the cytoplasm. The earliest changes observed seemed to play a protective role due to the overexpression of peripherin, AKTpan, AKTphospho, and metallothioneins; this expression had diminished by the time we analysed rats euthanised on day 82, when an increase in apoptosis was observed. The first cellular changes identified were activated microglia followed by astrogliosis and overexpression of GFAP and S100B proteins. CONCLUSION: Our data suggest that ALS could spread through CSF and that intracerebroventricular administration of cytotoxic ALS-CSF provokes changes similar to those found in sporadic forms of the disease.


Assuntos
Esclerose Lateral Amiotrófica/líquido cefalorraquidiano , Encéfalo/patologia , Líquido Cefalorraquidiano/metabolismo , Infusões Intraventriculares , Medula Espinal/patologia , Adulto , Esclerose Lateral Amiotrófica/patologia , Animais , Células Cultivadas , Líquido Cefalorraquidiano/química , Citotoxinas/farmacologia , Modelos Animais de Doenças , Humanos , Masculino , Neurônios Motores/citologia , Neurônios Motores/efeitos dos fármacos , Neurônios Motores/metabolismo , Ratos
20.
Neuroscience ; 145(3): 866-72, 2007 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-17291692

RESUMO

Although alpha7-receptors are considered the main target for neuroprotection, other receptor subtypes (alpha4beta2 or alpha3beta4) have also been implicated. Hence, we have used alpha7-transgenic mice, to study the hypothesis that alpha7-receptors play a dominant role in mediating neuroprotection in an in vitro model of ischemia. We have used rat and mouse hippocampal slices to establish the model of nicotinic neuroprotection against oxygen and glucose deprivation (OGD). Neuronal damage caused by OGD during 1 h plus 3 h re-oxygenation, was quantified by measuring lactate dehydrogenase (LDH) release from hippocampal slices. In rat hippocampal slices, OGD increased over twofold basal LDH release. Such increase was reduced when treated with 10-100 microM nicotine; maximal protection afforded by nicotine amounted to 46%. This neuroprotection was antagonized by the non-selective nicotinic receptor for acetylcholine (nAChR) blocker mecamylamine (10 microM). In hippocampal slices from wild-type control mice, nicotine (100 microM) decreased by 54.4% LDH release evoked by OGD plus re-oxygenation. In contrast, nicotine failed to exert neuroprotection in alpha7 knockout mice. This finding reinforces the view that the hippocampal neuroprotective effects of nicotine are predominantly linked to alpha7 receptors.


Assuntos
Glucose/fisiologia , Nicotina/farmacologia , Oxigênio/fisiologia , Receptores Nicotínicos/deficiência , Receptores Nicotínicos/genética , Animais , Feminino , Hipocampo/patologia , L-Lactato Desidrogenase/análise , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Neurônios/patologia , Oxirredução , Ratos , Ratos Sprague-Dawley , Receptor Nicotínico de Acetilcolina alfa7
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA