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Panagiotis Mizerakis Panagiota Stathopoulou George Tsiamis Mohammed N. Baeshen Jazem A. Mahyoub Ahmed M. Elazzazy Stamatia Bellou Eleni Sakoulogeorga Irene-Eva Triantaphyllidou Theodora Mazioti Panagiotis Katsoris George Aggelis 《Annals of microbiology》2017,67(10):643-654
The bacterial diversity of the outflows of Polichnitos (Lesvos, Greece) hot spring has been investigated. Cyanobacteria showing high sequence homologies with Phormidium sp. and Cyanobacterium aponinum were found. Members of the Alphaproteobacteria closely related to Rhodobium sp. Albidovulum sp., Rhodobacter sp., Microvigra sp., Nitratireductor sp. and Phaeobacter sp. Gammaproteobacteria, Betaproteobacteria and Firmicutes were represented by members of Idiomarina sp., Marinobacter sp., Shinella sp., Bacillus sp. and Clostridium sp. with sequence homologies ranging from 92% to 100%. Members of the Bacteroidetes and Planctomycetes were represented by sequences of novel phylogenetic linkages exhibiting 87–90% sequence homology with type strains. When the hot spring consortium was cultivated in bioreactor repeated batch culture under photo-autotrophic growth conditions at temperature < 30 °C, Cyanobacterium sp. dominated over Phormidium sp. Cyanobacterium sp. seems to have biotechnological potential since its extracellular broth exhibited a strong insecticidal activity against larvae of Aedes aegypti (a vector of important human diseases) and significant anti-cancer activity against the PC3 human prostate cancer cell line, while its toxicity against human endothelial cells was relatively low. 相似文献
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Hormonal regulation of spermatogenesis and spermiogenesis 总被引:1,自引:0,他引:1
Sofikitis N Giotitsas N Tsounapi P Baltogiannis D Giannakis D Pardalidis N 《The Journal of steroid biochemistry and molecular biology》2008,109(3-5):323-330
Normal testicular function is dependent upon hormones acting through endocrine and paracrine pathways both in vivo and in vitro. Sertoli cells provide factors necessary for the successful progression of spermatogonia into spermatozoa. Sertoli cells have receptors for follicle stimulating hormone (FSH) and testosterone which are the main hormonal regulators of spermatogenesis. Hormones such as testosterone, FSH and luteinizing hormone (LH) are known to influence the germ cell fate. Their removal induces germ cell apoptosis. Proteins of the Bcl-2 family provide one signaling pathway which appears to be essential for male germ cell homeostasis. In addition to paracrine signals, germ cells also depend upon signals derived from Sertoli by direct membrane contact. Somatostatin is a regulatory peptide playing a role in the regulation of the proliferation of the male gametes. Activin A, follistatin and FSH play a role in germ cell maturation during the period when gonocytes resume mitosis to form the spermatogonial stem cells and differentiating germ cell populations. In vitro cultures systems have provided evidence that spermatogonia in advance stage of differentiation have specific regulatory mechanisms that control their fate. This review article provides an overview of the literature concerning the hormonal pathways regulating spermatogenesis. 相似文献
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Sandra A. Tenaglia Tom M. McLellan Panagiota P. Klentrou 《European journal of applied physiology and occupational physiology》1999,80(2):76-83
In this study we examined the influence of menstrual cycle phase and oral contraceptive use on thermoregulation and tolerance during uncompensable heat stress. Eighteen women (18-35 years), who differed only with respect to oral contraceptive use (n = 9) or non-use (n = 9), performed light intermittent exercise at 40 degrees C and 30% relative humidity while wearing nuclear, biological and chemical protective clothing. Their responses were compared during the early follicular (EF, days 2-5) and mid-luteal (ML, days 19-22) phases of the menstrual cycle. Since oral contraceptives are presumed to inhibit ovulation, a quasi-early follicular (q-EF) and quasi-mid-luteal (q-ML) phase was assumed for the users. Estradiol and progesterone measurements verified that all subjects were tested during the desired phases of the menstrual cycle. Results demonstrated that rectal temperature (Tre) was elevated in ML compared with EF among the non-users at the beginning and throughout the heat-stress trial. For the users, Tre was higher in q-ML compared with q-EF at the beginning, and for 75 min of the heat-stress exposure. Tolerance times were significantly longer during EF [128.1 (13.4) min, mean (SD)] compared with ML [107.4 (8.6) min] for the nonusers, indicating that these women are at a thermoregulatory advantage during the EF phase of their menstrual cycle. For the users, tolerance times were similar in both the q-EF [113.0 (5.8) min] and q-ML [116.8 (11.2) min] phases and did not differ from those of the non-users. It was concluded that oral contraceptive use had little or no influence on tolerance to uncompensable heat stress, whereas tolerance was increased during EF for non-users of oral contraceptives. 相似文献
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Theodora Manolakou Valeria Kaltezioti Niki Prakoura Panagiotis Kavvadas Simone Reichelt-Wurm Harikleia Gakiopoulou Miriam Banas Bernhard Banas Maja T. Lindenmeyer Clemens D. Cohen Peter Boor Sonja Djudjaj Dimitrios T. Boumpas Christos Chatziantoniou Aristidis Charonis Panagiotis K. Politis 《Journal of cellular and molecular medicine》2023,27(9):1192-1205
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Panagiota Koskinioti Antonios A. Augustinos Danilo O. Carvalho Muhammad Misbah-ul-Haq Gulizar Pillwax Lucia Duran de la Fuente Gustavo Salvador-Herranz Rafael Argils Herrero Kostas Bourtzis 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2021,376(1818)
Aedes aegypti is the primary vector of arthropod-borne viruses including dengue, chikungunya and Zika. Vector population control methods are reviving to impede disease transmission. An efficient sex separation for male-only releases is crucial for area-wide mosquito population suppression strategies. Here, we report on the construction of two genetic sexing strains using red- and white-eye colour mutations as selectable markers. Quality control analysis showed that the Red-eye genetic sexing strains (GSS) is better and more genetically stable than the White-eye GSS. The introduction of an irradiation-induced inversion (Inv35) increases genetic stability and reduces the probability of female contamination of the male release batches. Bi-weekly releases of irradiated males of both the Red-eye GSS and the Red-eye GSS/Inv35 fully suppressed target laboratory cage populations within six and nine weeks, respectively. An image analysis algorithm allowing sex determination based on eye colour identification at the pupal stage was developed. The next step is to automate the Red-eye-based genetic sexing and validate it in pilot trials prior to its integration in large-scale population suppression programmes.This article is part of the theme issue ‘Novel control strategies for mosquito-borne diseases’. 相似文献
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Darviri Christina Artemiadis Artemios Tigani Xanthi Darvyri Panagiota Gnardellis Charalambos 《Sleep and biological rhythms》2018,16(2):253-258
Sleep and Biological Rhythms - There is apt evidence in favor of a significant association between sleep and mortality. So far, most studies examine sleep problems using comprehensive,... 相似文献
199.
Panagiota Moutevelis-Minakakis Maria Filippakou Charalambos Sinanoglou George Kokotos 《Journal of peptide science》2006,12(6):377-382
N-benzyloxycarbonyl-protected alpha- or beta-amino alcohols, easily prepared from alpha- and beta-amino acids, were converted into aldehydes and directly reacted with (triphenyl phosphoranylidene) acetonitrile, leading to unsaturated nitriles. Treatment of nitriles with NaN(3) and ZnBr(2) produced unsaturated gamma- and delta-amino tetrazoles, which were deprotected and converted to the corresponding saturated compounds by catalytic hydrogenation. For the case of delta-amino tetrazole, the methylation of the acidic moiety occurred after treatment with CH(2)N(2), leading to the N(1)- and N(2)-methylated constitutional isomers, which were separated by column chromatography and hydrogenated. 相似文献
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Panagiota?T. Foteinou Joseph?L. Greenstein Raimond?L. Winslow 《Biophysical journal》2015,109(4):838-849
Oxidative stress and calcium (Ca2+)/calmodulin (CaM)-dependent protein kinase II (CaMKII) both play important roles in the pathogenesis of cardiac disease. Although the pathophysiological relevance of reactive oxygen species (ROS) and CaMKII has been appreciated for some time, recent work has shown that ROS can directly oxidize CaMKII, leading to its persistent activity and an increase of the likelihood of cellular arrhythmias such as early afterdepolarizations (EADs). Because CaMKII modulates the function of many proteins involved in excitation-contraction coupling, elucidation of its role in cardiac function, in both healthy and oxidative stress conditions, is challenging. To investigate this role, we have developed a model of CaMKII activation that includes both the phosphorylation-dependent and the newly identified oxidation-dependent activation pathways. This model is incorporated into our previous local-control model of the cardiac myocyte that describes excitation-contraction coupling via stochastic simulation of individual Ca2+ release units and CaMKII-mediated phosphorylation of L-type Ca2+ channels (LCCs), ryanodine receptors and sodium (Na+) channels. The model predicts the experimentally measured slow-rate dependence of H2O2-induced EADs. Upon increased H2O2, simulations suggest that selective activation of late Na+ current (INaL), although it prolongs action potential duration, is not by itself sufficient to produce EADs. Similar results are obtained if CaMKII effects on LCCs and ryanodine receptors are considered separately. However, EADs emerge upon simultaneous activation of both LCCs and Na+ channels. Further modeling results implicate activation of the Na+-Ca2+ exchanger (NCX) as an important player in the generation of EADs. During bradycardia, the emergence of H2O2-induced EADs was correlated with a shift in the timing of NCX current reversal toward the plateau phase earlier in the action potential. Using the timing of NCX current reversal as an indicator event for EADs, the model identified counterintuitive ionic changes—difficult to experimentally dissect—that have the greatest influence on ROS-related arrhythmia propensity. 相似文献