28 research outputs found

    Molecular diversity of anthracnose pathogen populations associated with UK strawberry production suggests multiple introductions of three different Colletotrichum species.

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    Fragaria × ananassa (common name: strawberry) is a globally cultivated hybrid species belonging to Rosaceae family. Colletotrichum acutatum sensu lato (s.l.) is considered to be the second most economically important pathogen worldwide affecting strawberries. A collection of 148 Colletotrichum spp. isolates including 67 C. acutatum s.l. isolates associated with the phytosanitary history of UK strawberry production were used to characterize multi-locus genetic variation of this pathogen in the UK, relative to additional reference isolates that represent a worldwide sampling of the diversity of the fungus. The evidence indicates that three different species C. nymphaeae, C. godetiae and C. fioriniae are associated with strawberry production in the UK, which correspond to previously designated genetic groups A2, A4 and A3, respectively. Among these species, 12 distinct haplotypes were identified suggesting multiple introductions into the country. A subset of isolates was also used to compare aggressiveness in causing disease on strawberry plants and fruits. Isolates belonging to C. nymphaeae, C. godetiae and C. fioriniae representative of the UK anthracnose pathogen populations showed variation in their aggressiveness. Among the three species, C. nymphaeae and C. fioriniae appeared to be more aggressive compared to C. godetiae. This study highlights the genetic and pathogenic heterogeneity of the C. acutatum s.l. populations introduced into the UK linked to strawberry production

    An aberrant anterior lobe of the left lung in human

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    In some rare cases the human lung may shows variable accessory fissures that separate aberrant lung lobes. This case report describes an accessory fissure of the left lung of a 67-year-old Caucasian female cadaver that crossed the mediastinal, apical and anterior costal surfaces and thus it separates the organ into a small upper-medial-anterior lung lobe (lobus minimus) from a much larger aberrant lobe (lobus magnus). At the pulmonary hilum the artery, vein and bronchus of the small aberrant lobe were clearly visible. In the field of radiography the existence of such aberrant fissures and lobes have to be known in order to separate between simple anatomic variation of the lungs and a number of lung pathologies

    Formation of ultrapotassic magma via crustal contamination and hybridization of mafic magma: an example from the Stomanovo monzonite, Central Rhodope Massif, Bulgaria

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    Generally all orogenic ultrapotassic rocks are formed after melting of metasomatized sub-continental lithospheric mantle via subducted crustal mica-bearing lithologies. Here we present another possible model, based on the study of the small Stomanovo ultrapotassic monzonite porphyry intrusion in the Central Rhodope Massif, Bulgaria. The monzonite dated at 30.50 ± 0.46 Ma is intruded into the voluminous Oligocene (31.63 ± 0.40 Ma) Bratsigovo–Dospat ignimbrite. The monzonite hosts both normally and reversely zoned clinopyroxene phenocrysts. The normally zoned clinopyroxene is characterized by gradually diminishing core-to-rim Mg no. (89–74), whereas the reversely zoned clinopyroxene has green Fe-rich cores (Mg no. 71–55) mantled by normally zoned clinopyroxene (Mg no. 87–74). Neither the core of the normally zoned clinopyroxene nor the Fe-rich green cores are in equilibrium with the host monzonite. This ultrapotassic monzonite shows more radiogenic Sr isotopes ((87Sr/86Sr)i = 0.71066) and ϵNd(t) = −7.8 to −8.0 that are distinct from the host ignimbrites with (87Sr/86Sr)i = 0.70917–0.70927 and ϵNd(t) = −4.6 to −6.5. The Sr–Nd isotopic data and the presence of copious zircon xenocrysts from the underlying metamorphic basement suggest extensive crustal assimilation. Our observations indicate that the Stomanovo ultrapotassic monzonite formed after extensive lower or middle crustal fractional crystallization from an evolved magma producing cumulates. The process was followed by hybridization with primitive mantle-derived magma and subsequent continuous crustal contamination. We suggest that instead of inheriting their high K2O and large-ion lithophile element enrichments from slab-derived/metasomatic fluids, the Stomanovo ultrapotassic monzonite may owe some of its unusually high alkalinity to the assimilation of potassium-rich phases from the Rhodope Massif basement rocks

    A comparative light-microscopic morphological study of the postnatal changes in the myocardium of the left and right ventricles in rat

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    According to literature data, age-related remodelling of the myocardium is related to the development of hypertrophy of the cardiomyocytes and interstitial fibrosis. In the present study, we observed accumulation of collagen in the walls of the vessels, interstitium and perivascular zones in Wistar rats from various age groups. Normally, the bundles of cardiomyocytes and the separate cells are surrounded by thin layers of peri- and endomysium. In the aging myocardium, hypertrophy of cardiomyocytes, transformation of fibroblasts into myofibroblasts and accumulation of extracellular matrix proteins in the interstitium are observed. Histological analyses of aging rat hearts show progressive loss of cardiomyocytes due to necrosis and apoptosis. Thus, preserved cardiac muscle cells undergo a process of compensatory hypertrophy. In our study, we investigated postnatal changes in the myocardium of 15 adult male Wistar rats, distributed in the following age groups: 2 weeks, 1, 3, 6 and 12 months old. We used routine haematoxylin and eosin staining and Mallory`s trichrome stain in order to analyse morphological changes in the aging myocardium in the wall of the left and right ventricle, as well as changes undergone by cardiomyocytes. In conclusion, it can be stated that by aging, heart morphology becomes impaired at organ level, as well as at individual cardiomyocyte level. Aging of myocardium is a dynamic process, characterized by hypertrophy of cardiomyocytes, reduced capillary density and increased deposition of collagen. Considering the functional dissimilarities between the left and right ventricle (a more pronounced effect of the afterload on the left ventricle), processes in the left ventricle follow a more dynamic pattern and reactive fibrosis occurs earlier. Changes in the right ventricle occur at a relatively smooth pace

    A correlation between postnatal changes in the expression of nitric oxide synthase (NOS) in the rat myocardium and its morphological characteristics

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    The constitutive production of nitric oxide (NO) by the different isoforms of the enzyme nitric oxide synthase (NOS) is a major factor in the regulation of cardiac function under physiological and pathological conditions alike. As such, it affects various manifestations of the process of myocardial aging in the postnatal period, includ­ing hypertrophy and fibrosis of the ventricles and their remodelling, impaired relaxation and decreased cardiac output. The aim of the present study was to establish whether a correlation exists between changes in the expres­sion of neuronal NOS (nNOS) and the morphological characteristics of the myocardium during various periods of postnatal development. We used fifteen male Wistar rats, distributed in five age groups - 2 weeks old, 1 month old, 3 months old, 6 months old, and 12 months old, each group containing 3 animals. We used routine haematox­ylin and eosin staining and specific immunohistochemical staining for nNOS. During the early postnatal period (1-3 months), we observed a normal histological appearance of the cardiomyocytes and the interstitial space. As aging progressed (6-12 months), we reported the presence of cardiomyocytic hypertrophy, with narrowing of the interstitial space, focal myocytolysis and pronounced accumulation of collagen fibres. The immunohistochemi­cal staining for nNOS revealed that enzyme activity intensified over the course of postnatal development. It was distributed heterogeneously in the various layers of the myocardium and we noted differences in the enzyme ex­pression between the left and the right ventricle.In conclusion, the increased expression of nNOS in senescent rats probably represents a protective mechanism against age-related hypertrophy of the cardiomyocytes. Further studies could possibly establish the importance of regional differences in enzyme expression within the myocardium

    Quantitative characteristics of the myocardium and the cardiomyocytes during different stages of the postnatal development in Wistar rats

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    Until recently there was a consensus that the growth of the heart during the foetal and postnatal development of the rat is primarily due to hyperplasia of the cardiomyocytes but at a certain moment during the early postnatal development of the heart, cardiomyocyte hyperplasia ceases and during the late postnatal period, heart growth occurs due to hypertrophy of the cardiac muscle cells. For this reason, in healthy rats, no significant changes in the number and size of cardiomyocytes are observed. The mean size of the cardiomyocytes increases in correlation with body growth during the postnatal development and these cells also possess the ability for additional hypertrophy in response to increased workload. While studying cell size, most authors measure the diameter of the cells in transverse histological slides by adopting a cylindrical model of the cell. The diameter is measured either directly in the individual cells or is determined indirectly.In the present study, the quantitative data on the morphology of the free wall of the left and right ventricle in Wistar rats have been obtained during the analysis of the hearts of 15 male rats, divided into five groups: two-week-old; one-month-old; three-month-old; six-month-old; twelve-month-old. For morphometric analysis we used five slides of the heart of each animal by randomly selecting zones in the material where there were no massive tears. The morphometric characteristics are presented and organized through schemes and diagrams, demonstrating the dynamics in the following quantitative indices: thickness of the free wall of the left and right ventricle (μm), transverse section of the cardiomyocytes (μm2) cardiomyocytic density (number of cells/mm2). The changes observed in these indices reflect a tendency for age-related hypertrophy. They are more dynamic and start earlier in the left ventricle and occur in a significantly smoother pattern in the right ventricle

    A comparative quantitative analysis of postnatal changes in cardiomyocites in normotensive and spontaneously hypertensive rats

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    Differences between the size of cardiomyocytes from normotensive and hypertensive hearts have been studied by a small number of authors and have been limited to measurements of the cellular diameter, length and cross-sec­tional area. The aim of the present study was to analyse a broader range of morphometric markers in order to as­sess the size of the cardiac muscle cells and to compare the obtained data between normotensive Wistar rats and spontaneously hypertensive rats. Results were obtained by studying the hearts of 15 male normotensive Wistar rats, distributed in five age groups: 2 weeks old, 1, 3, 6, and 12 months old, each group containing three animals, as well as 6 spontaneously hypertensive rats, distributed in two age groups: 1 month old (young) and 6 months old (adult), each group containing three animals. With the advance in age, the thickness of the free wall of the ven­tricles and the cross-sectional area of cardiomyocytes from both ventricles increased, as did the cross-section­al area of cardiomyocytic nuclei. Conversely, a decrease in the cardiomyocytic density was noted. These chang­es were more pronounced in the left ventricle of both normotensive and spontaneously hypertensive rats but oc­curred at an earlier age and were better expressed in the group of spontaneously hypertensive rats. The morpho­metric markers analysed in the present study represent a statistically significant assessment, which illustrates the differences between hypertrophy and remodelling of the myocardium induced by advancing age under normo­tensive conditions and those initiated by arterial hypertension