Peter Hristov
Bulgarian Academy of Sciences
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Featured researches published by Peter Hristov.
Cancer Letters | 1997
Peter Hristov; Lubomir Petrov; Elevter M. Russanov
The mechanism of sonodynamic action in tumor cells is poorly investigated. It is known that ultrasound generates free radicals in phosphatidylcholine liposomes used as a membrane model. The participation of lipid peroxidation products in the mechanisms of physiological suppression of cell multiplication has been investigated for some tumor cells. In the present work ultrasound-induced lipid peroxidation in Ehrlich ascitic tumor cells was studied. Ultrasonication increased the level of lipid peroxidation quantified by the TBARS method in homogenates from Ehrlich ascitic tumor cells. Changes in the fatty acid composition of lipids from Ehrlich ascitic tumor cells irradiated by sonication were observed. TBARS production obtained by ultrasound was compared to TBARS production obtained by widely used chemical inductors. The free-radical processes evoked by ultrasound are of interest in antitumor therapy.
Infection, Genetics and Evolution | 2011
Denitsa Teofanova; Vaia Kantzoura; Stephen Walker; Georgi Radoslavov; Peter Hristov; Georgios Theodoropoulos; Ilia Bankov; Alan Trudgett
The genetic diversity of liver fluke populations in three different countries from Eastern Europe (Greece, Bulgaria, and Poland) was determined and compared with available data from other countries. Specifically, SNPs from regions of two nuclear genes, 28S rDNA, β-tubulin 3 and an informative region of the mitochondrial genome were examined. Two major lineages for the 28S rDNA gene based on the highly polymorphic 105th nucleotide position were found. These lineages were widely and almost equally spread not only through the countries studied but also in other investigated geographical areas. Two basic lineages and additional haplotypes were defined for the mtDNA gene region which consisted of the cytochrome c oxidase subunit III gene, transfer RNA histidine gene and cytochome b gene. The basic lineages were observed within Greek, Bulgarian, and Polish Fasciola hepatica populations but the distribution of additional haplotypes differed between the populations from the three countries. For the β-tubulin 3 gene multiple polymorphic sites were revealed but no explicit clades. The SNPs were spread unequally in all studied geographical regions with an evident distinction between the Greek and Polish specimens. Additional genotypes for the 28S rDNA region as well as haplotypes of the mtDNA region that were typical for the Greek or Polish populations were observed. Significant polymorphisms for β-tubulin 3 gene were displayed with decreasing percentage of presence within populations from Greece to Poland. There was an amino acid substitution in β-tubulin 3 protein found only among Polish specimens. It is hypothesized that genotypic differences between Greek, Bulgarian, and Polish liver fluke populations are due to territorial division and genetic drift in past epochs.
Systematic Parasitology | 2015
Borislav Stoyanov; Boyko Neov; Plamen Pankov; Georgi Radoslavov; Peter Hristov; Boyko B. Georgiev
The genus Aphalloides Dollfus, Chabaud & Golvan, 1957 consists of two species parasitic in the body cavity of sand gobies. Its systematic position in the superfamily Opisthorchioidea Looss, 1899 is unresolved and it has been placed by various authors in three families, i.e. Cryptogonimidae Ward, 1917, Heterophyidae Leiper, 1909 and Opisthorchiidae Looss, 1899. Its type-species, Aphalloidescoelomicola Dollfus, Chabaud & Golvan, 1957, is here reported from the Caucasian dwarf goby Knipowitschia caucasica (Berg) in the lagoon Atanasovsko Lake, Black Sea coast of Bulgaria (new geographical record). The species is redescribed based on light and scanning electron microscopy demonstrating some characters typical for the Cryptogonimidae but also characters distinguishing it from the other genera of the family such as the lack of tegumental spines and the presence of a short excretory vesicle, which does not extend into the forebody. Phylogenetic analysis of the D2-D3 expansion segments of the 28S rRNA gene suggests phylogenetic relationships of Aphalloidescoelomicola with the cryptogonimid Centrovarium lobotes (MacCallum, 1895). These data support the affiliation of the genus Aphalloides to the family Cryptogonimidae. The peculiar morphology of the species in the genus is explained by their unusual life-cycles characterised by progenetic development; sand gobies being simultaneously second intermediate and definitive hosts.
ZooKeys | 2014
Sevdan Nedelchev; Milka Elshishka; Stela Lazarova; Georgi Radoslavov; Peter Hristov; Vlada Peneva
Abstract An unknown species belonging to the genusCalcaridorylaimus Andrássy, 1986 was collected from the litter of broadleaf forests dominated by Castanea sativa Mill. and mixed with Quercus daleshampii Ten. and Fagus sylvatica L. on Belasitsa Mountain, south-western Bulgaria. Calcaridorylaimus castaneae sp. n. is characterised by its long body (1.4–2.1 mm), lip region practically not offset, vulva transverse, short odontostyle (14.5–16 μm) and tail (75.5–110.5 μm, c=14.7–23.6; c’=2.9–4.4) in females and 38–46 μm long spicules with small spur before their distant end in males. It is most similar to C. andrassyi Ahmad & Shaheen, 2004, but differs in having transverse vs pore-like vulva and shorter spicules (38–46 μm vs 52–57 μm). An identification key to the species of the genus Calcaridorylaimus is proposed. Phylogenetic analyses were performed on 18S and D2-D3 expansion domains of 28S rRNA genes by Neighbor-Joining, Maximum Likelihood and Bayesian Inference methods. The phylograms inferred from 18S sequences showed closest relationships of the new species with some species belonging to the genus Mesodorylaimus. However, insufficient molecular data for members of both genera do not allow the phylogenetic relationships of Calcaridorylaimus and the new species described herein to be elucidated.
Animal Genetics | 2015
Peter Hristov; Denitsa Teofanova; Boyko Neov; Georgi Radoslavov
The Bulgarian Grey cattle (BGC) and theShorthorn Rhodopean cattle (SRC) are Balkan indigenousbreeds that are part of the Podolian and Brachicerous(Busha) cattle groups respectively. Concerning the mtDNAdiversity of Balkan cattle breeds, previous studies focusedon Busha cattle and Grey cattle populations.
Mitochondrial DNA | 2017
Peter Hristov; Nikolai Spassov; Nikolai Iliev; Georgi Radoslavov
Abstract Neolithic/Chalcolithic livestock domestication is an important issue for understanding the mode of life and economics of ancient human communities. The Balkans appears to be a crucial point for clarifying the socio-economical interrelations between the Oldest Middle Eastern/Anatolian and newly formed cultures in Europe. Two main hypotheses regarding the early history of cattle domestication, from their ancestor – the aurochs, have been discussed: multipoint domestication centers or single point origin and subsequent worldwide dissemination. In this study, we provide molecular data about the Balkan aurochs for the first time as well as additional information for the Neolithic/Chalcolithic cattle populations in this geographic location. A total of seventeen samples from different ancient settlements were analyzed according to D-loop control region. The results did not show different genetic profile of wild and domestic populations. All haplotypes were found to belong to the basic macro-haplogroup T. The majority of specimens (n = 14) were defined to form a new Balkan-specific T6 haplogroup. Only two of the ancient samples analyzed were assigned to the T3 haplotype predominating in Europe. We attempt to throw new light on the earliest cattle domestication events in Europe, thus, the results presented are discussed in two directions: (a) The possibility of local independent domestication processes in Neolithic South-Eastern Europe; (b) The single point domestication in the Middle East and subsequent cattle dissemination in Europe. Our data does not exclude the possibility for independent domestication events followed by a second wave of parallel dissemination of cattle herds via the Mediterranean route.
Archive | 2012
Peter Hristov; Denitsa Teofanova; Ivan Mehandzhiyski; Lyuben Zagorchev; Georgi Radoslavov
© 2012 Hristov et al., licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Application of Milk Proteins Genetic Polymorphism for Selection and Breeding of Dairy Cows in Bulgaria
Journal of Apicultural Research | 2017
Georgi Radoslavov; Peter Hristov; Rositsa Shumkova; Ivan Mitkov; Daniela Sirakova; Maria Bouga
In this study, we present for the first time SNPs analysis of a coI mitochondrial DNA (mtDNA) gene segment of the local Rhodopa Mountain honey bee, A. m. rodopica, that is well investigated, based on morpho-ethological and biochemical studies. The analysis was performed on adult honey bee workers that were sampled from 29 colonies that are under the control of the Bulgarian National Beekeeping Association. Our data are compared with analogous studies obtained from other A. mellifera subspecies, and we describe a specific characteristic duplication of the coI gene for the Rhodopes honey bee that can be applied as a genetic marker to discriminate the local Bulgarian honey bees and to support the related conservation activities.
Archive | 2012
Denitsa Teofanova; Peter Hristov; Aneliya Yoveva; Georgi Radoslavov
Parasitic diseases are huge problem for human and veterinary medicine and for economy, agriculture and wildlife management. One of these diseases is fasciolosis, which is caused by two trematode species, Fasciola hepatica (liver fluke) and Fasciola gigantica. Only F. hepatica is a concern in Europe and Americas but the distribution of both species overlaps in many areas of Africa and Asia (Mas-Coma et al., 2005). F. hepatica occurs mostly in cattle, sheep and wild ruminants. Recently, worldwide losses in animal productivity due to fasciolosis were estimated at over US
Biotechnology & Biotechnological Equipment | 2012
Peter Hristov; Denitsa Teofanova; Ivan Mehandzhiyski; A. Yoveva; Georgi Radoslavov
3.2 billion per annum (Spithill et al., 1999). The infection of humans has been regarded as accidental for many years. However, fasciolosis is now recognized as an emerging human disease: the World Health Organization (WHO, 2006) has estimated that 2.4 million people are infected with F. hepatica and a further 180 million are at risk of infection (Mas-Coma et al., 1999).