Mem Inst Oswaldo Cruz
November 2024
Background: Acanthamoebae are causative agents of severe and complicated human infections without a standard effective therapy to date. Therefore, the research is focused on the development of new amoebicidal drugs based on the natural products. Plants of the family Lamiaceae are typical with several phenolic secondary metabolites that make them interesting in medical point of view.
View Article and Find Full Text PDFGene flow between species may last a long time in plants. Reticulation inevitably causes difficulties in phylogenetic reconstruction. In this study, we looked into the genetic divergence and phylogeny of 20 Lilium species based on multilocus analyses of 8 genes of chloroplast DNA (cpDNA), the internally transcribed nuclear ribosomal DNA (nrITS) spacer and 20 loci extracted from the expressed sequence tag (EST) libraries of L.
View Article and Find Full Text PDFSoil nutrients, dormant axillary meristem availability, and competition can influence plant tolerance to damage. However, the role of potential bud banks (adventitious meristems initiated only after injury) is not known. Examining Central European field populations of 22 species of short-lived monocarpic herbs exposed to various sources of damage, we hypothesized that: (1) with increasing injury severity, the number of axillary branches would decrease, due to axillary meristem limitation, whereas the number of adventitious shoots (typically induced by severe injury) would increase; (2) favorable environmental conditions would allow intact plants to branch more, resulting in stronger axillary meristem limitation than in unfavorable conditions; and (3) consequently, adventitious sprouting would be better enabled in favorable than unfavorable conditions.
View Article and Find Full Text PDFA protease secreted in Bacillus pumilus KMM 62 culture liquid on different growth stages was isolated using ion-exchange chromatography. On the basis of pattern of specific chromogenic substrates hydrolysis and inhibitory analysis the protease was classified as subtilisin like serine protease. The molecular weight ofprotease is 31 kDa.
View Article and Find Full Text PDFWe studied plus-maze behavior of inbred Krushinskii-Molodkina, Wistar, and black-hooded rats (originating from the Long-Evans outbred strain) differing by predisposition to audiogenic seizures. The severity of audiogenic seizures partially correlated with anxiety and negatively correlated with the total level of locomotor activity in the elevated plus-maze. The anxiety parameters in Krushinskii-Molodkina rats were evaluated after injection of anticonvulsant levetiracetam and anxiolytic afobazol.
View Article and Find Full Text PDFThe novel antiepileptic drug levetiracetam (keppra, 80 mg/kg, i.p.) produces a pronounced anticonvulsant effect on all parameters of the audiogenic locomotion response in Wistar rats, leading to the prevention of acoustic seizures approximately in 50% animals.
View Article and Find Full Text PDFBackground And Aims: Adventitious sprouting from the hypocotyle and roots in monocarpic herbs has been confirmed in previous experimental studies as a means to avoid bud limitation after severe injury in annual and biennial plants. Data regarding the role of adventitious sprouting in natural populations, however, were lacking. The aim of the present study was to assess whether adventitious sprouting occurs in natural populations and how it is affected by plant size, plant injury, plant cover and environmental characteristics.
View Article and Find Full Text PDFZh Vyssh Nerv Deiat Im I P Pavlova
January 2009
The duration and severity of cataleptic freezing after audiogenic seizures were investigated in rats of several genotypes with different predisposition to audiogenic epilepsy. These genotypes were the Krushinsky-Molodkina strain (KM--the audiogenic seizure prone strain), the Wistar and two new substrains selected from hybrids KM x Wistar for high ("4") and low ("0") audiogenic seizure susceptibility. The drug injections, which modulated the audiogenic fit severity, induced the changes in catalepsy too.
View Article and Find Full Text PDFThe new antiepileptic drug levetiracetam (LVT) at doses of 40 and 80 mg/kg exhibits a pronounced anticonvulsant effect, influencing all the parameters of audiogenic epileptiform seizures (AES) in Krushinsky-Molodkina (KM) rats. The latent period of the motor reaction was increased 3-15 times compared to control, and the intensity of single convulsive episodes was significantly decreased. Changes were also detected in the profile of the first stage of motor activity, and the "two-wave" reaction was observed in 50-80% of animals.
View Article and Find Full Text PDFFolia Microbiol (Praha)
January 2008
The Staphylococcus strains acquired from scrapings from hospital environments were identified to the species level based on their biochemical properties. From the monitored sample the Staphylococcus epidermidis strains were selected for more accurate typing and tested on their virulence factor and ribotyped. The biotyping of S.
View Article and Find Full Text PDFThe influence of the cultivation conditions on Bacillus pumilus KMM 62 growth and effectiveness of the production of a subtilisin-like serine proteinase were investigated. Enzyme accumulation in the culture fluid reached the maximum value after 32 and 46-48 h of growth; it depends on the composition of the nutrient medium. The ratio of the concentrations of two main components of the medium, peptone and inorganic phosphate, which was optimal for enzyme biosynthesis was determined by multifactor experiments.
View Article and Find Full Text PDFPublished data on the mechanisms involved in the action of levetiracetam (LVT, 2S-(oxo-1-pyrrolidinyl)butanoic acid amide), a widely used agent for the adjunctive therapy of partial epilepsy of different genesis, have been analyzed. A unique profile of the anticonvulsant action of LVT was already revealed at the screening stage: this agent was not effective in the traditional tests, but it demonstrated a pronounced protective effect in kindling models and in the experiments on mice sensitive to the audiogenic convulsions. Now it is commonly accepted that the LVT mode of action is different from that of the other known antiepileptic drugs.
View Article and Find Full Text PDFProteinases secreted during the early and late stationary phases have been isolated from the culture liquid of Bacillus amyloliquefaciens H2 using CM-cellulose ion-exchange chromatography with subsequent FPLC on a Mono S column. Considering the character of hydrolysis of specific chromogenic substrates and the type of inhibition, these enzymes were identified as subtilisin-like proteinases. The molecular weight of both proteinases is 29 kD.
View Article and Find Full Text PDFWe demonstrated high sensitivity of the brain neurotransmitter system to high-molecular-weight heparin in Wistar rats. Single and repeated administration of heparin modulated the content of monoamines and neurotransmitter amino acids in the hippocampus, striatum, and cerebral cortex. Antistress activity of high-molecular-weight heparin and its positive effects on memory under experimental conditions suggest that this preparation in low doses can be used in the therapy of neurological and age-related diseases.
View Article and Find Full Text PDFB. intermedius have been shown previously to secrete two serine proteinases: glutamyl endopeptidase 2 and subtilisin 2 during the late stationary phase, with maximal levels of the enzymes activities recorded at the 40th and 44th hours of growth, respectively. In the current study, we analyzed the impact of various culture medium components on biosynthesis of these proteinases.
View Article and Find Full Text PDFWe evaluated the role of nitric oxide and lipid peroxidation in the pathophysiological mechanisms of seizures in genetically epilepsy prone (GEP) rats and DBA/2 mice with genetically determined audiogenic epilepsy. In rats and mice acoustic stimulation led to locomotor activation followed by clonic-tonic seizures. The contents of nitric oxide and lipid peroxidation products at the peak of seizures markedly surpassed the control level.
View Article and Find Full Text PDFThe dynamics of excitatory (glutamate, aspartate) and inhibitory (GABA, glycine) neurotransmitter amino acid contents in the cerebrospinal fluid were studied in 110 patients with hemispheric ischemic insult. These studies revealed significant increases in the levels of glutamate and aspartate in the first six hours of illness, and the level and duration of these changes correlated with the severity of the insult. Peak GABA and glycine levels were seen at the end of the first day after strokes, reflecting the delayed activation of the mechanisms of protective inhibition.
View Article and Find Full Text PDFThe effect of cyclic GABA derivative TZ-146 on the content of catecholamines, serotonin, their metabolites, and neurotransmitter amino acids in rat hypothalamus and brain stem was studied by high-performance liquid chromatography with electrochemical detection. Opposite changes in the content of homovanillic acid, aspartate, glutamate, and glycine in the examined structures were accompanied by inhibition of dopamine metabolism. Possible participation of cerebral glutamatergic system in the effect of TZ-146 is discussed.
View Article and Find Full Text PDFZh Nevrol Psikhiatr Im S S Korsakova
April 1999
The dynamics of the levels of both excitatory (aspartate, glutamate) and inhibitory (GABA, glycine) neurotransmitter amino acids was estimated in cerebrospinal fluid of 110 patients with hemispheric ischemic stroke. A significant increase of the contents of glutamate and aspartate was found beginning with the first 6 hours of the disease onset. The degree and duration of such elevation correlated with severity of the stroke.
View Article and Find Full Text PDFPhys Rev B Condens Matter
July 1996
The morphofunctional state of different links of the sympathoadrenal system under the action of neuroleptics haloperidol and sulpiride was studied on the model of immobilization stress in rats. The drugs were shown to possess the effect of the pharmacological correction of hormone content in the adrenals and the level of the neuromediator activity of the adrenergic nerves at different stages of immobilization stress. The data obtained indicate the anti-stress action of the studied neuroleptics.
View Article and Find Full Text PDFThe antistress affect of the substance P1-4 N-terminal fragment (ARG-Pro-Lys-Pro, 100 mkg/kg, i.p.) has been studied on the model of immobilization stress in rats.
View Article and Find Full Text PDFBiull Eksp Biol Med
March 1988
The mediator activity of the peripheral catecholaminergic systems (the adrenergic nerves of dura mater and the concentrations of noradrenaline and adrenaline in the adrenals of rats) during dynamic and immobilization stress was investigated with the help of fluorescent microscopy and spectrofluorometry. Neuropeptides--dalargin and another enkephalin analog--were injected intraperitoneally, 150 mg/kg. A visible antistress action of these neuropeptides has been demonstrated, it was more marked after treatment with dalargin.
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