Short neuropeptide F in integrated insect physiology. / 昆虫生理中短神经肽Fçš„åŠŸèƒ½ç ”ç©¶è¿›å±•.

The short neuropeptide F (sNPF) family of peptides is a multifunctional group of neurohormones involved in the regulation of various physiological processes in insects. They have been found in a broad spectrum of species, but the number of isoforms in the precursor molecule varies from one to four. The receptor for sNPF (sNPFR), which belongs to the G protein-coupled receptor family, has been characterized in various insect orders and was shown to be an ortholog of the mammalian prolactin-releasing peptide receptor (PrPR). The sNPF signaling pathway interacts with other neurohormones such as insulin-like peptides, SIFamide, and pigment-dispersing factors (PDFs) to regulate various processes. The main physiological function of sNPF seems to be involved in the regulation of feeding, but the observed effects are species-specific. sNPF is also connected with the regulation of foraging behavior and the olfactory system. The influence of sNPF on feeding and thus energy metabolism may also indirectly affect other vital processes, such as reproduction and development. In addition, these neurohormones are involved in the regulation of locomotor activity and circadian rhythm in insects. This review summarizes the current state of knowledge about the sNPF system in insects.

Differential Effects of Invasive Anodal Trans-spinal Direct Current Stimulation on Monosynaptic Excitatory Postsynaptic Potentials, Ia Afferents Excitability, and Motoneuron Intrinsic Properties Between Superoxide Dismutase Type-1 Glycine to Alanine Substitution at Position 93 and Wildtype Mice.

In presymptomatic amyotrophic lateral sclerosis (ALS), spinal motoneurons (MNs) have reduced firing patterns and synaptic excitation levels. Preliminary data indicated that in the SOD1 G93A mouse model of ALS, monosynaptic excitatory postsynaptic potentials (EPSPs) evoked in spinal MN by Ia proprioceptive afferent stimulation could be facilitated by trans-spinal direct current stimulation (tsDCS). However, which element of the Ia afferent-MN circuit is affected by tsDCS, and whether tsDCS-induced EPSP facilitation is a general phenomenon or specific to the superoxide dismutase type-1 (SOD1) Glycine to Alanine substitution at position 93 (G93A) mutation, remain to be determined. In this study, we have applied 15-minute tsDCS to the lumbar segments of presymptomatic SOD1 and wildtype (WT) mice and explored its impact on MN passive membrane properties, EPSP amplitude, and Ia afferent activity. While anodal tsDCS induced short-lasting EPSP facilitation in both SOD1 and WT mice, Ia afferent activity and passive membrane properties were altered only in SOD1 mice. Interestingly, EPSP amplitudes of SOD1 mice remained facilitated for at least 1 h after current application, but no long-lasting effect was observed in WT mice. Moreover, anodal tsDCS failed to induce any long-lasting changes in MN passive membrane properties in both SOD1 and WT mice. Conversely, cathodal tsDCS decreased Ia afferent induced EPSP amplitudes only during current application in SOD1 MNs, and no significant effects on Ia afferents excitability were observed. Our findings indicate the high susceptibility of SOD1 MNs to tsDCS and highlight the potential of this neuromodulation technique for the treatment of ALS.

Influence of Artemisia annua L. on toll-like receptor expression in brain of mice infected with Acanthamoeba sp.

The treatment of acanthamoebiasis is a still a problem. Our previous studies showed that the application of extracts from Artemisia annua L. significantly prolonged the survival of mice infected by Acanthamoeba. This plant has medicinal properties in the treatment of human parasitic diseases. The aim of this study was to evaluate the effects of A. annua on expression of Toll-like receptors (TLRs) 2 and 4 in brain of mice with Acanthamoeba infection. Mice were infected with Acanthamoeba sp. strain Ac309 (KY203908) by intranasal inoculation without and after application of A. annua extract. The administration of extract from A. annua significantly reduced the level of expression of TLR2 and modified the level of expression of TLR4. A. annua extract is a natural substance that is well tolerated in animals and may be considered as a combination therapy in treatment of acanthamoebiasis. Our study suggested that A. annua extract may be used as an alternative therapeutic tool.

Hygiene pests as vectors for parasitic and bacterial diseases in humans

Diseases transmitted by hygiene pests remain a very serious problem in spite of fast developments in science and medicine. The present study focuses on pests carrying germs that pose a threat to human health and life. The quick pace of life, the need to satisfy human needs and mass production of food sometimes result in flagrant sanitary, hygienic and epidemiological deficiencies. These irregularities are conducive to hygiene pests, which, when not held in check by proper control measures, may act more efficiently and quickly.

Evaluation of the effectiveness of tea tree oil in treatment of Acanthamoeba infection.

Eye diseases caused by amoebae from the genus Acanthamoeba are usually chronic and severe, and their treatment is prolonged and not very effective. The difficulties associated with therapy have led to attempts at finding alternative treatment methods. Particularly popular is searching for cures among drugs made of plants. However, no substances with total efficacy in treating Acanthamoeba keratitis have been identified.Results of our semi in vivo studies of tea tree oil simulating eyeball infection demonstrated 100% effectiveness in the case of both trophozoites and cysts of amoebae from the genus Acanthamoeba. The action of tea tree oil indicates that this is the first substance with a potential ability to quickly and effectively remove the amoebae from the eye. Tea tree oil has the ability to penetrate tissues, which allows it to destroy amoebae in both the shallow and deep layers of the cornea. The present research into the use of tea tree oil in the therapy of Acanthamoeba infection is the first study of this type in parasitology. It offers tremendous potential for effective treatment of Acanthamoeba keratitis and other diseases caused by these protozoa.

THE USE OF EXTRACTS FROM PASSIFLORA SPP. IN HELPING THE TREATMENT OF ACANTHAMOEBIASIS.

Chronic progressive diseases of the central nervous system such as granulomatous amoebic encephalitis, amoebic keratitis, amoebic pneumonitis and also skin infections caused by free-living amoebae (Acanhamoeba spp.) are a significant challenge for pharmacotherapy. This is due to the lack of effective treatment because of encystation, which makes the amoebae highly resistant to anti-amoebic drugs. A very inter- esting and promising source of future drugs in this area are plant materials obtained not only from the habitat but also from plant in vitro culture as an alternative source of biomaterials. Alcoholic extracts from leaves of Passiflora incarnata, P. caerulea, P. alata (Passifloraceae) and from callus cultures were evaluated in vito for amoebicidal activity. Phytochemical analysis showed that all extracts contained phenolic compounds including flavonoids? Biological study revealed that all extracts showed amoebostatic and amoebicidal properties in concentrations from 4 to 12 mg/mL. Extracts of P. alata leaf and callus showed the most effective activities (IC5, 4.01 mg/mL, IC,5 7.29 mg/mL, respectively) after 48 h of exposure, which was correlated with the highest concentration of total phenolics and flavonoids in comparison with other extracts.

Artemisia annua L. as a plant with potential use in the treatment of acanthamoebiasis.

The treatment of acanthamoebiasis is a great problem. Most cerebral invasions end with death, and the treatment of ocular invasions is usually long-lasting and not very effective. Numerous plant extracts and substances isolated from plants, which are effective against trophozoites or cysts, have been studied in the treatment of acanthamoebiasis. However, no agents that are simultaneously effective against both developing forms of amoebae have been discovered yet. It seems that such a plant which fulfils both tasks is Artemisia annua L. Our studies showed that water, alcohol and chloroform extracts from the herb A. annua L. can be applied in general and local treatment or in combined therapy with antibiotics in the treatment of acanthamoebiasis. Extracts from this plant show not only in vitro but also in vivo effects. Studies carried out on experimental animals infected with amoebae show that the application of these extracts significantly prolongs the survival of the animals.

Parasitic diseases in humans transmitted by vectors.

Despite the considerable progress of medicine, parasitic diseases still pose a great threat to human health and life. Among parasitic diseases, those transmitted by vectors, mainly arthropods, play a particular role. These diseases occur most frequently in the poorest countries and affect a vast part of the human population. They include malaria, babesiosis, trypanosomiasis, leishmaniasis and filariasis. This study presents those vector-transmitted diseases that are responsible for the greatest incidence and mortality of people on a global scale. Attention is focused primarily on diseases transmitted by mosquitoes, flies, Hemiptera and ticks.

Genotypic characterization of amoeba isolated from Acanthamoeba keratitis in Poland.

Free-living amoebae belonging to the genus Acanthamoeba are the causative factor of many diseases. Among others, they cause Acanthamoeba keratitis (AK), a condition that usually occurs in contact lens wearers, though it is also observed in non-wearers. The number of diagnosed cases of AK increased more than eightfold during 8 years in the USA, and a proportional increase in frequency also occurred in Poland and Europe. Cases of AK are usually diagnosed late, and their therapy is difficult and rarely successful. AK is an uncommon diagnosis in Poland. The increased number of positive cases observed in our laboratory may reflect the growing at-risk population of contact lens wearers. Acanthamoeba as a genus of facultative human parasites is currently classified into 17 genotypes. Isolates belonging to seven genotypes were found to be associated with AK. One genotype in particular, T4, was found to be overrepresented in human disease. The main finding of our study is that in Poland, AK is almost always associated with the T4 genotype.

Hyperglycaemia and intramitochondrial glycogen granules in the brain of mice. Ultrastructural study.

The mechanism of cytotoxic effects of hyperglycaemia on the brain has not yet been explained and the proposed hypotheses are not fully convincing. In the present study, we aimed to assess the effect of high doses of glucose on the ultrastructure of the mice brain. The results, which are in agreement with the literature data, show that the administration of a single high dose of glucose, as well as its chronic application, leads to accumulation of glycogen granules in the cytoplasm of astrocytes. A new observation is the detection of glycogen granules in the ultrastructurally changed mitochondria of astrocytes as well as in the mitochondria of some synapses. Our hypothesis assumes that excess of glucose may cause an increase in the vulnerability of the brain mitochondria. This in turn may enable glucose and cytoplasmic enzymes to penetrate into the mitochondria and they therein synthesise glycogen. Mitochondrial dysfunction may in turn lead to neurodegeneration by apoptotic process.