Number of results to display per page
Search Results
4862. Chromosomal studies on Greek populations of four small rodent species
- Creator:
- Mitsainas, George P., Rovatsos, Michail Th., Karamariti, Irene, and Giagia-Athanasopoulou, Eva B.
- Type:
- article and TEXT
- Subject:
- Myoxus glis, Dryomys nitedula, Spermophilus citellus, Myodes glareolus, karyotype, and heterochromatin
- Language:
- English
- Description:
- The results of a karyological study on the dormice Myoxus glis (2n=62) and Dryomys nitedula (2n=48), the ground squirrel Spermophilus citellus/i> (2n=40) and the red bank vole Myodes glareolus (2n=56) from Greece are presented. A part from the clarification of their diploid chromosome number, a more elaborate study of their karyotype was conducted and the G- and C- banding patterns are provided for the first time in Greek populations of these species. In particular, heterochromatin distribution in D. nitedula seems to be more extensive than previously thought, contrasting M. glis, in which heterochromatin seems to be absent. On the other hand, the Y chromosome of M. glareolus was found to be a fully heterochromatic submetacentric. In overall, the comparison of our karyological results, with those of other Eurasian populations reinforce the belief that the karyotypes of the studied species are conservative, displaying small degrees of variation, usually restricted to the size and morphology of the sex chromosomes.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/
4863. Chromosome analysis of Proteocephalus osculatus (Cestoda: Proteocephalidea)
- Creator:
- Petkevičiūtė, Romualda
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Language:
- English
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
4864. Chromosome mapping of 28S ribosomal genes in 11 species of Cassidinae (Coleoptera: Chrysomelidae)
- Creator:
- Lopes, Amália T., Fernandes, Flávia R., and Schneider, Marielle C.
- Type:
- article, model:article, and TEXT
- Subject:
- Coleoptera, Chrysomelidae, Cassidini, Mesomphaliini, constitutive heterochromatin, diploid number, nucleolar organizer region, and rDNA genes
- Language:
- English
- Description:
- In this study, we examined for the first time the distribution of the 28S ribosomal genes in beetles of the subfamily Cassidinae. More than 55% of the species in this subfamily have a similar karyotype, 2n = 16 + Xyp. For this work, we selected species belonging to the tribes Cassidini and Mesomphaliini, which have, respectively, the most conserved and diversified karyotype characteristics within the Cassidinae. An analysis of 11 species revealed that rDNA sites on one pair of autosomes is the most frequent pattern, occurring in 10 species. This condition occurs in the seven genera examined and in species of both of the tribes, Cassidini and Mesomphaliini. Nevertheless, the differences in the locations of 28S rDNA were more pronounced in the tribe Cassidini and among species with similar karyotype characteristics. On the other hand, in Mesomphaliini, the increase in the diploid number was not accompanied by an increase in the number of ribosomal sites. Moreover, the comparison of the number and localization of major rDNA sites with the distribution of constitutive heterochromatin indicates that there is no direct correlation between the dispersion of constitutive heterochromatin and 28S rDNA genes in Cassidinae.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
4865. Chromosome polymorphism in Polish populations of northern birch mouse Sicista betulina
- Creator:
- Fedyk, Stanisław, Chętnicki, Włodzimierz, L. Ruprecht, Andrzej, and Cichocki, Jan
- Type:
- article and TEXT
- Subject:
- variability of karyotype and chromosome evolution
- Language:
- English
- Description:
- Somatic chromosomes of 17 northern birch mice, Sicista betulina, originating from lowland and Tatra Mountain populations were studied. In the whole studied material constant diploid number of chromosomes (2n = 32) was found. Polymorphism of a pair of large-sized autosomes was found; acrocentric, subtelocentric and submetacentric chromosomes in homozygous or heterozygous state form the polymorphic pair. Consequently, chromosome arm number (NF) varies within 60 and 62. In this regard Polish populations of northern birch mouse differ from those of more eastward distribution (NF = 63–64).
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/
4866. Chromozomální podivnost ptakopyska
- Creator:
- Robovský, Jan
- Type:
- article, model:article, and TEXT
- Language:
- Czech
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
4867. Chromozomová teritoria
- Creator:
- Heneberg, Petr
- Type:
- article and TEXT
- Language:
- Czech
- Description:
- V rozporu s vžitými představami nevlají interfázní chromozomy náhodně jádrem. Jsou organizovány do chromozomálních teritorií sloužících k efektivní regulaci genové exprese, ale majících za následek i vznik řady nádorových onemocnění. and Contrary to previous views, interphase chromosomes do not flutter randomly across the nucleus. They are organized into chromosomal territories utilized for effective regulation of gene expression, but also responsible for the onset of many cancers.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/
4868. Chronic and acute effects of different antihypertensive drugs on femoral artery relaxation of L_NAME hypertensive rats
- Creator:
- Sládková, M., Kojšová, S., Lýdia Jendeková, and Oľga Pecháňová
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, hypertenze, hypertension, L_NAME-induced hypertension, indapamide, hydrochlorothiazide, captopril, femoral artery, vasorelaxation, 14, and 612
- Language:
- English
- Description:
- We aimed to compare the effects of chronic and acute administration of structurally different antihypertensives, diuretics - indapamide and hydrochlorothiazide, ACE inhibitor - captopril and indapamide+captopril combination on endothelium-dependent relaxation of femoral artery isolated from nitric oxide (NO)-deficient rats. In the chronic experiment, femoral artery was isolated from Wistar rats receiving L-NAME (40 mg/kg/day) solely or with indapamide (1 mg/kg/day), hydrochlorothiazide (10 mg/kg/day), captopril (10 mg/kg/day), and indapamide+captopril combination for seven weeks. In the acute in vitro experiment, the incubation medium with femoral artery isolated from L-NAMEhypertensive rats was supplemented with investigated antihypertensives in the same concentration 10-4 mol/l. Interestingly, chronic L-NAME treatment did not cause a reduction of vasorelaxation. Indapamide+captopril elevated relaxation above the control level and completely prevented blood pressure increase induced by L-NAME. Acute incubation with captopril only or indapamide+captopril improved relaxation of femoral artery isolated from L-NAMEhypertensive rats, while the incubation with all antihypertensives increased vasorelaxation of femoral artery isolated from control Wistar rats. In conclusion, NO might be involved in the indapamide- and hydrochlorothiazide-induced improvement of vasorelaxation, while different vasorelaxing factors (prostacyclin, EDHF) contribute to the captoprilinduced improvement of vasorelaxation. During the chronic treatment additive and synergic effects of indapamide and captopril may contribute to the prevention of hypertension and increase of vasorelaxation., M. Sládková, S. Kojšová, L. Jendeková, O. Pecháňová., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
4869. Chronic atropine administration diminishes the contributon of vasoactive intestinal polypeptide to heart rate regulation
- Creator:
- Jitka Kuncová, Faitová, Š., Capouch, J., Milan Štengl, and Jana Slavíková
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Experimentální medicína, fyziologie, polypeptidy, srdeční síně, potkan, physiology, polypeptides, atria of heart, Rattus norvegicus, vasoactive intestinal polypeptide, atropine, vagus nerve stimulation, 14, and 616-092
- Language:
- English
- Description:
- Vasoactive intestinal polypeptide (VIP) is implicated in the modulation of vagal effects on the heart rate. In this study, the impact of acute and chronic atropine administration on VIP levels in rat heart atria was investigated in relation to heart rate in the course of vagus nerves stimulation. Anaesthetised control and atropinised (10 mg/kg/day for 10 days) rats pretreated with metipranolol and phentolamine that were either given or not a single dose of atropine were subjected to bilateral vagus nerve stimulation (30 min: 0.7 mA, 20 Hz, 0.2 ms). VIP concentrations in the atria were determined afte reach stimulation protocol. In control rats with or without single atropine administration, the heart rate upon vagal stimulation was higher than in atropinised animals with or without single atropine dose, respectively. VIP concentrations in the control atria were significantly decreased after the stimulation; the decrease was comparable both in the absence and presence of a single dose of atropine. Compared to controls, VIP levels were significantly decreased after chronic atropine treatment and they were not further reduced by vagal stimulation and single atropine administration. Administration of VIP antagonist completely abolished the differences in the heart rate upon vagal stimulation between control and atropinised groups. In conclusion, the data indicate that chronic atropine administration affects VIP synthesis in rat heart atria and consequently it modifies the heart rate regulation., J. Kuncová, Š. Faitová, J. Capouch, M. Štengl, J. Slavíková., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
4870. Chronic cigarette smoking alters circulating sex hormones and neuroactive steroids in premenopausal women
- Creator:
- Michaela Dušková, Kateřina Šimůnková, Hill, M., Velíková, M., Kubátová, J., Lyudmila Kantcheva, Hana Kazihnitková, Hruškovičová, H., Pospíšilová, H., Rácz, B., Salátová, M., Veronika Cirmanová, Eva Králíková, Luboslav Stárka, and Antonín Pařízek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie člověka, human physiology, smoking, menstrual cycle, luteal phase, follicular phase, sex hormones, neuroactive steroids, 14, and 612
- Language:
- English
- Description:
- a1_Chronic smoking alters the circulating levels of sex hormones and possibly also the neuroactive steroids. However, the data available is limited. Therefore, a broad spectrum of free and conjugated steroids and related substances was quantified by GC-MS and RIA in premenopausal smokers and in age-matched (38.9±7.3 years of age) non-smokers in the follicular (FP) and luteal phases (LP) of menstrual cycle (10 non-smokers and 10 smokers, in the FP, and 10 non-smokers and 8 smokers in the LP). Smokers in both phases of the menstrual cycle showed higher levels of conjugated 17-hydroxypregnenolone, 5α-dihydroprogesterone, conjugated isopregnanolone, conjugated 5α-pregnane-3β,20α-diol, conjugated androstenediol, androstenedione, testosterone, free testosterone, conjugated 5α-androstane-3α/β,17β-diols, and higher free testosterone index. In the FP, the smokers exhibited higher levels of conjugated pregnenolone, progesterone, conjugated pregnanolone, lutropin, and a higher lutropin/follitropin ratio, but lower levels of cortisol, allopregnanolone, and pregnanolone. In the LP, the smokers exhibited higher levels of free and conjugated 20α-dihydropregnenolone, free and conjugated dehydroepiandrosterone, free androstenediol, 5α-dihydrotestosterone, free and conjugated androsterone, free and conjugated epiandrosterone, free and conjugated etiocholanolone, 7α/β-hydroxy-dehydroepiandrosterone isomers, and follitropin but lower levels of estradiol and sex hormone binding globulin (SHBG) and lower values of the lutropin/follitropin ratio. In conclusion, chronic cigarette smoking augments serum androgens and their 5α/β-reduced metabolites (including GABAergic substances) but suppresses the levels of estradiol in the LP and SHBG and may induce hyperandrogenism in female smokers., a2_The female smokers had pronouncedly increased serum progestogens but paradoxically suppressed levels of their GABA-ergic metabolites. Further investigation is needed concerning these effects., M. Dušková ... [et al.]., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public