RESUMO: A associação entre herbicidas e demais pesticidas pode causar reflexos tanto no manejo de plantas daninhas quanto de cultivadas. O objetivo deste trabalho foi avaliar a resposta da associação de diferentes herbicidas com inseticidas ou fungicidas pertencentes a diferentes grupos químicos sobre o desenvolvimento e rendimento de grãos de trigo, cultivar ORS Vintecinco. O delineamento experimental foi o de blocos ao acaso com três repetições. O experimento foi constituído por 33 tratamentos: testemunha sem aplicação, aplicação dos herbicidas 2,4-D (1.005 g e.a. ha-1), bentazon (756 g i.a. ha-1), metsulfuron-methyl (3 g i.a. ha-1) e pyroxsulam (16 g i.a. ha-1), de forma isolada ou associados com os inseticidas chlorfluazuron (15 g i.a. ha-1), chlorpyrifos (720 g i.a. ha-1), deltamethrin (5 g i.a. ha-1) e methomyl (5 g i.a. ha-1), ou com os fungicidas azoxystrobin (100 g i.a. ha-1), carbendazim (250 g i.a. ha-1) e propiconazole (190 g i.a. ha-1). Avaliou-se a tolerância relativa (TR), a massa da parte aérea seca (MPAS) das plantas e os componentes de rendimento e rendimento de grãos. De modo geral, pyroxsulam apresentou maior número de interações sinérgicas com os inseticidas e fungicidas utilizados, reduzindo dessa forma a TR e MPAS das plantas, destacando-se a associação pyroxsulam + chlorpyrifos pelo menor nível de TR (45%) e maior redução de MPAS (52%). Todas as associações de herbicidas com o inseticida chlorpyrifos e a maioria das associações com o fungicida propiconazole resultaram em redução do rendimento de grãos em relação à aplicação isolada dos mesmos herbicidas ou à testemunha sem aplicação.

ABSTRACT: The combination of herbicides and other pesticides can influence weed and crop management. This study aimed to evaluate the response of the combination of different herbicides with insecticides or fungicides of different chemical groups on the development and yield of wheat grains of the cultivar ORS Vintecinco. The experimental design was a randomized block design with three replications. The experiment consisted of 33 treatments, as follows: control without application and application of the herbicides 2,4-D (1,005 g a.e. ha-1), bentazon (756 g a.i. ha-1), metsulfuron-methyl (3 g a.i. ha-1), and pyroxsulam (16 g a.i. ha-1), isolated or combined with the insecticides chlorfluazuron (15 g a.i. ha-1), chlorpyrifos (720 g a.i. ha-1), deltamethrin (5 g a.i. ha-1), and methomyl (5 g a.i. ha-1) or with the fungicides azoxystrobin (100 g a.i. ha-1), carbendazim (250 g a.i. ha-1), and propiconazole (190 g a.i. ha-1). Relative tolerance (RT), shoot dry matter (SDM), yield components, and grain yield were evaluated. In general, pyroxsulam had the highest number of synergistic interactions with insecticides and fungicides, reducing RT and SDM, especially the combination pyroxsulam + chlorpyrifos due to a lower RT level (45%) and higher SDM reduction (52%). All combinations of herbicides with the insecticide chlorpyrifos and most of the combinations with the fungicide propiconazole led to a reduction of grain yield when compared to their isolated application or to control without application.

The present study evaluated electrocardiographic alterations in rats with epilepsy submitted to an acute myocardial infarction (AMI) model induced by cardiac ischemia and reperfusion. Rats were randomly divided into two groups: control (n=12) and epilepsy (n=14). It was found that rats with epilepsy presented a significant reduction in atrioventricular block incidence following the ischemia and reperfusion procedure. In addition, significant alterations were observed in electrocardiogram intervals during the stabilization, ischemia, and reperfusion periods of rats with epilepsy compared to control rats. It was noted that rats with epilepsy presented a significant increase in the QRS interval during the stabilization period in relation to control rats (P<0.01). During the ischemia period, there was an increase in the QRS interval (P<0.05) and a reduction in the P wave and QT intervals (P<0.05 for both) in rats with epilepsy compared to control rats. During the reperfusion period, a significant reduction in the QT interval (P<0.01) was verified in the epilepsy group in relation to the control group. Our results indicate that rats submitted to an epilepsy model induced by pilocarpine presented electrical conductivity alterations of cardiac tissue, mainly during an AMI episode.

Administration of pilocarpine causes epilepsy in rats if status epilepticus (SE) is induced at an early age. To determine in detail the electrophysiological patterns of the epileptogenic activity in these animals, 46 Wistar rats, 7-17 days old, were subjected to SE induced by pilocarpine and electro-oscillograms from the cortex, hippocampus, amygdala, thalamus and hypothalamus, as well as head, rostrum and vibrissa, eye, ear and forelimb movements, were recorded 120 days later. Six control animals of the same age range did not show any signs of epilepsy. In all the rats subjected to SE, iterative spike-wave complexes (8.1 ± 0.5 Hz in frequency, 18.9 ± 9.1 s in duration) were recorded from the frontal cortex during absence fits. However, similar spike-wave discharges were always found also in the hippocampus and, less frequently, in the amygdala and in thalamic nuclei. Repetitive or single spikes were also detected in these same central structures. Clonic movements and single jerks were recorded from all the rats, either concomitantly with or independently of the spike-wave complexes and spikes. We conclude that rats made epileptic with pilocarpine develop absence seizures also occurring during paradoxical sleep, showing the characteristic spike-wave bursts in neocortical areas and also in the hippocampus. This is in contrast to the well-accepted statement that one of the main characteristics of absence-like fits in the rat is that spike-wave discharges are never recorded from the hippocampal fields.

In this study, the behavioral and electroencephalographic (EEG) analysis of seizures induced by the intrahippocampal injection in rats of granulitoxin, a neurotoxic peptide from the sea anemone Bunodosoma granulifera, was determined. The first alterations occurred during microinjection of granulitoxin (8 µg) into the dorsal hippocampus and consisted of seizure activity that began in the hippocampus and spread rapidly to the occipital cortex. This activity lasted 20-30 s, and during this period the rats presented immobility. During the first 40-50 min after its administration, three to four other similar short EEG seizure periods occurred and the rats presented the following behavioral alterations: akinesia, facial automatisms, head tremor, salivation, rearing, jumping, barrel-rolling, wet dog shakes and forelimb clonic movements. Within 40-50 min, the status epilepticus was established and lasted 8-12 h. These results are similar to those observed in the acute phase of the pilocarpine model of temporal lobe epilepsy and suggest that granulitoxin may be a useful tool not only to study the sodium channels, but also to develop a new experimental model of status epilepticus.

The purpose of this study was to investigate the effect of the level of injury on the serum level of norepinephrine (Nor) and epinephrine (Epi) at rest and after maximal exercise in individuals with paraplegia. Twenty-six male spinal cord-injured subjects with complete paraplegia for at least 9 months were divided into two groups of 13 subjects each according to the level of injury, i.e., T1-T6 and T7-T12. Serum Nor and Epi concentrations were measured by HPLC-ECD, at rest (PRE) and immediately after a maximal ergospirometric test (POST). Statistical analysis was performed using parametric and non-parametric tests. Maximal heart rate, peak oxygen uptake, and PRE and POST Nor were lower in the T1-T6 than in the T7-T12 group (166 ± 28 vs 188 ± 10 bpm; 18.0 ± 6.0 vs 25.8 ± 4.1 ml kg-1 min-1; 0.54 ± 0.26 vs 0.99 ± 0.47 nM; 1.48 ± 1.65 vs 3.07 ± 1.44 nM). Both groups presented a significant increase in Nor level after exercise, while only the T7-T12 group showed a significant increase in Epi after exercise (T1-T6: 0.98 ± 0.72 vs 1.11 ± 1.19 nM; T7-T12: 1.24 ± 1.02 vs 1.89 ± 1.57 nM). These data show that individuals with paraplegia above T6 have an attentuated catecholamine release at rest and response to exercise as compared to subjects with injuries below T6, which might prevent a better exercise performance in the former group.