[A functional interpretation of various morphological formations in the cerebral cortex from the aspect of evolution].
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Biological Evolution↗
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In vitro analysis of the cellular resistance to chemotherapeutic BCNU.
Our assays in vitro show that BCNU inhibits cell proliferation in the C6 cell line experimental glioma and is dose-dependent, starting from 0.5 microgram/ml of the drug with just an hour of exposure. For every tested concentration of BCNU it is shown that, from the fifth day after exposure, cellular resistance appeared. This resistance is justified by the capacity of cell DNA reparation. A study of the clonogenic capacity of the C6 cells exposed to BCNU also shows the appearance of cellular resistance for doses of 0.5 microgram/ml and 1 microgram/ml. Furthermore, the exposure of C6 cell cultures to BCNU at these levels produces a cellular evolution towards more differentiated morphological patterns.
Carmustine↗
Cell type-specific differences in metabolic activation of N-nitrosodiethylamine by human lung cancer cell lines.
The metabolism of N-nitrosodiethylamine (NDEA) and its modulation by inhibitors of cytochrome P450 and prostaglandin H synthetase enzymes was investigated in seven well-differentiated early-passage human lung cancer cell lines. NDEA metabolism was assessed by covalent binding and evolution of carbon dioxide. Morphological diagnosis of cell lines was done by light and electron microscopy. Two cell lines (NCI-H69, NCI-H128) with characteristics of small-cell cancer did not metabolize NDEA. Two cells lines (NCI-H322) with features of adenocarcinoma, comprised of Clara cells, and (NCI-H727), with features of pulmonary endocrine cells, were more potent than all other cell lines in metabolizing NDEA. A cell line divided from an adenocarcinoma but comprised of alveolar type-II cells (NCI-H358) metabolized NDEA predominantly via prostaglandin H synthetase. Similarly, several cell lines with features of well-differentiated pulmonary endocrine cells (NCI-H727, NCI-H460) metabolized NDEA via prostaglandin H synthetase, while the cell line comprised of Clara cells (NCI-H322) activated the nitrosamine by cytochrome P450 but not by prostaglandin H synthetase. Although cancer cells may react differently from normal cells to xenobiotics, our data provide substantial evidence for the hypothesis that--as in the hamster--Clara cells and pulmonary endocrine cells are potential major targets of NDEA carcinogenesis in human lung. It is of particular interest that different cell types activate the nitrosamine via different enzyme systems.
Adenocarcinoma↗
[Process of mandibular ossification in mice and evolutionary morphology (experimental study by means of vital staining)].
The injection in vivo of red alizarin S. in young mice during the post-natal period, enabled to show the mechanisms that were modeling the mandible during its development (by apposition-resorption). So it was possible to study : the processes of ossification involved in the eruption of the teeth, the modifications of the bony relief and the alterations of the mandibular angle. It has been attempted to find the links between these phenomena and muscular excitation, function and behaviour. The study of the osseous - muscular - mandibular anatomical set provided a good example of the principle described in Evolutionary morphology: "The comparatively free evolution of the elements in the anatomical set that they constitute (Sakka, 1973)."
Animals↗
Voluntary hip dislocation in Down's syndrome: report of two cases.
Two cases of monolateral voluntary hip dislocation in Down's syndrome are reported. No surgical procedure was permitted by the family in either case, thus showing the natural evolution of the joint morphology. In the case observed a year after the onset of hip dislocation CT Scan already showed an initial smoothing of the posterior acetabular wall. In the other case, after a 9 year follow-up, the voluntary hip dislocation was followed by progressive subluxation and fixed dislocation at the end. This suggests that only early surgical treatment can prevent this outcome.
Child↗
[Morphological variants of alcoholic hyalin and possible ways of its evolution].
Possible ways of alcohol hyalin evolution were studied by repeated electron microscopic examinations of the livers of 2 patients with acute alcoholic hepatitis Four types of ultrastructure of alcoholic hyalin were found: parallely oriented fibrillae, randomly oriented fibrillae, fine granular and large granular (spotlike) substance. Examinations of the material from repeated biopsies showed fibrillar hyalin to be "young" and to turn into "old" hyalin of granular structure. The evolution of alcoholic hyalin from fibrillar to granular is accompanied by hepatocyte necrosis and leukotaxic effect.
Adult↗
[Toxoplasmosis in agriculture workers exposed to the risk of contamination].
Five-hundred-and-eighty-eight cattle and agricultural workers were surveyed. One-hundred-and-fifty of them were randomly selected, and they underwent leukograms and absolute eosinophil counts for enabling the study of their hematologic state. A 55% positivity rate was obtained among patients studied through the toxoplasmin intradermoreaction technique from Czechoslovakia. Historical and morphologic aspects, biological characteristics, evolutive cycle, pathologic characteristics, clinical manifestations, as well as the epidemiology of Toxoplasma gondii are reviewed.
Agricultural Workers' Diseases↗
[Surface microscopic patterns of an experimental model of surgically induced carcinogenesis].
An experimental model of carcinogenesis is developed by authors, using internal urinary diversion in Wistar rats. Results show the transformation of normal digestive pattern, discovering proliferative-inflammatory changes at the first time which after go to an histiotypical tumorous pattern. They conclude at the carcinogenicity of the presented surgical model and is described the evolution of the superficial morphological pattern during the tumorigenic process.
Animals↗
[Myocardial hypertrophy and arterial hypertension].
Myocardial hypertrophy in different cardiac diseases is considered to be an adaptive mechanism to the increase of hemodynamic load which might restore to normal radius/wall thickness ratio and consequently to normalize wall stress. However, it has been widely demonstrated that beside the hemodynamic load, other factors contribute to the development of myocardial hypertrophy. It has been shown that in hypertensive patients, functional abnormalities (increased contribution of atrial systole to total diastolic filling, increased isovolumic relaxation period, prolonged diastolic duration, slowed ventricular filling and altered diastolic distensibility) precede the development of myocardial hypertrophy. Thus, in hypertensive patients, sign and symptoms of heart failure could be manifested in absence of myocardial hypertrophy, and might be exclusively due to diastolic dysfunction (with normal systolic function). Systolic function might be involved and compromised late when focal myocardial cell death and fibrosis occur and consequently ¿adequate¿ hypertrophy is shifted to ¿inadequate¿. This evolution is accompanied by morphological and functional changes of the myocardium similar to those encountered in dilated cardiomyopathy. Impairment of systolic function in ¿inadequate¿ hypertrophy is also due to structural changes; altered ratio between sarcomers and mitochondria, increased intercapillary distance, sarcoplasmatic reticulum dysfunction, increase of collagene component with a consequent increment of wall rigidity, hypertrophy of arterial tunica media, which alters coronary flow and coronary reserve. The progression of these morpho-functional abnormalities is a very slow process, in which adaptive mechanism mediated by several enzymes and contractile protein, contribute to maintain myocardial viability. However, over the long course, disseminated focal myocardial cell necrosis and fibrosis, which is an evolving process, is considered to be the main responsible factor for the irreversible myocardial damage and systolic dysfunction in advanced myocardial inadequate hypertrophy.
Cardiomegaly↗
[Pancreatic and extrapancreatic fluid collections following acute and chronic pancreatitis].
Intra- or extrapancreatic liquid collections are common complications for acute and chronic pancreatitis, with variable morphologic features and possible evolution toward complications. A total of 31 liquid collections (pseudocysts, ascites and/ or enzymatic pleurisy) in 22 patients are presented. The study assems the etiology, the diagnostic methods and the treatment of the liquid collections. The preferred surgical treatment is either cysto-digestive anastomosis or distal pancreatic resections. Also some new therapeutic modalities are analyzed percutaneous or endoscopic drainage.
Acute Disease↗
Human evolution: taxonomy and paleobiology.
This review begins by setting out the context and the scope of human evolution. Several classes of evidence, morphological, molecular, and genetic, support a particularly close relationship between modern humans and the species within the genus Pan, the chimpanzee. Thus human evolution is the study of the lineage, or clade, comprising species more closely related to modern humans than to chimpanzees. Its stem species is the so-called 'common hominin ancestor', and its only extant member is Homo sapiens. This clade contains all the species more closely-related to modern humans than to any other living primate. Until recently, these species were all subsumed into a family, Hominidae, but this group is now more usually recognised as a tribe, the Hominini. The rest of the review sets out the formal nomenclature, history of discovery, and information about the characteristic morphology, and its behavioural implications, of the species presently included in the human clade. The taxa are considered within their assigned genera, beginning with the most primitive and finishing with Homo. Within genera, species are presented in order of geological age. The entries conclude with a list of the more important items of fossil evidence, and a summary of relevant taxonomic issues.
Animals↗
Phylogeny of the ectomycorrhizal mushroom genus Alnicola (Basidiomycota, Cortinariaceae) based on rDNA sequences with special emphasis on host specificity and morphological characters.
Alnicola (=Naucoria, pro parte) is a mushroom genus of strictly temperate, obligately ectomycorrhizal species, traditionally included in the family Cortinariaceae. Most Alnicola spp. are primarily host specific on Alnus, although a few are mycobionts of Salix or other hosts. The different species of Alnicola exhibit unique morphological (cystidia, pileipellis) and cytological (dikaryotic or monokaryotic hyphae) characters. This makes the genus Alnicola of particular interest for studying the evolution of host specificity and morphological characters in ectomycorrhizal basidiomycetes. We used a combination of classical morphological and phylogenetic methods (rDNA ITS and LSU sequences) to address the following questions: (i) Is Alnicola monophyletic? And (ii) Are characters like host specificity or microscopical structures synapomorphic for certain clades? The study included nearly all currently known European Alnicola sp. Our results demonstrated that, on one hand, the genus Alnicola is polyphyletic, with sistergroup relationships to Hebeloma, Anamika or the clades /Hymenogaster I and /Hymenogaster II. On the other hand, Alnicola splits into three well-supported clades corresponding to the sections Alnicola, Submelinoides, and Salicicolae. The strict host-specificity to Alnus is a derived character and has occurred at least twice. The following morphological characters are synapomorphic for defined clades: the spindle-shaped hymenial cystidia for sect. Alnicola, the hymeniform pileipellis for sect. Submelinoides, and monocaryotic/clampless hyphae for sect. Salicicolae and its sistergroup /Hymenogaster II. As a taxonomical consequence, polyphyly of Alnicola implies that the sects. Submelinoides and Salicicolae need to be segregated from Alnicola.
Basidiomycota↗
Evolvability.
Evolvability is an organism's capacity to generate heritable phenotypic variation. Metazoan evolution is marked by great morphological and physiological diversification, although the core genetic, cell biological, and developmental processes are largely conserved. Metazoan diversification has entailed the evolution of various regulatory processes controlling the time, place, and conditions of use of the conserved core processes. These regulatory processes, and certain of the core processes, have special properties relevant to evolutionary change. The properties of versatile protein elements, weak linkage, compartmentation, redundancy, and exploratory behavior reduce the interdependence of components and confer robustness and flexibility on processes during embryonic development and in adult physiology. They also confer evolvability on the organism by reducing constraints on change and allowing the accumulation of nonlethal variation. Evolvability may have been generally selected in the course of selection for robust, flexible processes suitable for complex development and physiology and specifically selected in lineages undergoing repeated radiations.
Animals↗
Dendritic to globular morphology transition in ternary alloy solidification.
The evolution of solidification microstructures in ternary metallic alloys is investigated by adaptive finite element simulations of a general multicomponent phase-field model. A morphological transition from dendritic to globular growth is found by varying the alloy composition at a fixed undercooling. The dependence of the growth velocity and of the impurity segregation in the solid phase on the composition is analyzed and indicates a smooth type of transition between the dendritic and globular growth structures.
Journal Article↗
Functional behavior of primary rat liver cells in a three-dimensional perfused microarray bioreactor.
We have previously described the design and operation of a microfabricated bioreactor that supports perfused 3D culture of liver cells and facilitates evolution of tissue-like morphological structures. Here, we describe the functional viability of cells maintained in this microarray bioreactor and examine the influence of different seeding protocols on the evolution of structure and function in comparison with static culture. Primary rat hepatocytes were seeded into the perfusion reactors either as single-cell suspensions immediately after isolation or as spheroidal aggregates formed over a 2- to 3-day period. Initial studies in which cells were cultured for 7 days postisolation revealed significantly greater functional activity and morphological stability of cells that were preaggregated for up to 3 days before seeding in the reactor, compared with direct seeding of single cells. Total albumin secretion and urea genesis rates in single-cell reactor cultures declined significantly during this initial culture period while remaining constant in preaggregated reactor cultures. Longer term studies indicate that rates of albumin secretion and urea genesis are maintained at constant levels through 15 days postisolation. These metabolic rates are an order of magnitude higher than observed for the same preaggregated structures cultured statically with comparable medium ratio and exchange conditions. The metabolic function data are supported by light microscopy images showing viable tissue structures, and electron microscopy images that reveal tight junctions, glycogen storage, and bile canaliculi.
Albumins↗
Merkel cell carcinoma: squamous and atypical fibroxanthoma-like differentiation in successive local tumor recurrences.
Merkel cell carcinoma (MCC) is a rare, frequently lethal, primary neuroendocrine carcinoma of the skin. Histopathologically, it appears as a dermal nodule of small, undifferentiated malignant cells. Historically, MCC was considered to be an eccrine carcinoma. Recognition of its neuroendocrine features later led to the hypothesis that it arose from Merkel cells in the skin, although recent evidence revisits the question of an epithelial origin. We present a case of MCC arising on the temple of a 78-year-old male, in association with an actinic keratosis. Three years later, a local tumor recurrence showed a mixed malignancy comprising small cell neuroendocrine and large cell squamoid components. A further recurrence at the site two years later, after local radiotherapy, revealed a bizarre pleomorphic large cell morphology with retention of immunohistochemical features of a neuroendocrine carcinoma. Evolution to a bizarre pleomorphic large cell neoplasm has been recorded in malignant tumors treated by radiotherapy, but is unique for MCC. The association of this MCC with an actinic keratosis and the development of squamoid differentiation in a local recurrence support the link between MCC and epithelial neoplasia. In addition, its evolution to an atypical fibroxanthoma-like morphology is of interest, because some view atypical fibroxanthomas as bizarre variants of squamous cell carcinoma.
Aged↗
A morphological and morphometric study of the prosimian lung: the lesser bushbaby Galago senegalensis.
The lung of the lesser bushbaby (Galago senegalensis) has been investigated morphologically and morphometrically using the transmission and scanning electron microscopes. Grossly and microscopically, the bushbaby lung was found to be essentially similar to that of the other primates and the mammals in general. Subtle morphometric differences were, however, observed, with the bushbaby lung being generally structurally less sophisticated than that of the other primates on which comparable data are available, except for man. The weight-specific surface area of the blood-gas (tissue) barrier in G. senegalensis was 25 cm2 g-1. The thickness of the blood-gas barrier was 0.355 micron and the weight specific total anatomical pulmonary diffusing capacity 0.045 mlO2 sec-1 mbar1 kg-1. The morphological similarity of the galago lung to that of man gives sufficient grounds to justify its possible use in human pulmonary studies but caution has been called for in the general utilisation of primate tissues without first establishing their morphological characteristics, just because the primates are taken to be evolutionally close to man. The dearth of morphological studies on the various organ systems of the prosimians is pointed out.
Animals↗
Phylogeny and evolution of Orchis and allied genera based on ITS DNA variation: morphological gaps and molecular continuity.
Phylogenetic relationships among members of genus Orchis and allied genera Aceras, Anacamptis, Barlia, Dactylorhiza, Gymnadenia, Himantoglossum, Neotinea, Ophrys, Platanthera, and Serapias were inferred from nucleotide sequence variation in the internal transcribed spacer (ITS) regions of nuclear ribosomal DNA. Sequences were subjected to various alignments by changing the gap opening and extension parameters. After a preliminary parsimony analysis, the alignment with the lowest homoplasy indicators was chosen as optimal. The phylogenetic analysis, carried out on the optimal alignment by using Gennaria as an outgroup and a total of 31 taxa, showed that all the genera considered in this study are nested in Orchis despite their distinct morphological features. Genus Orchis is divided into two major clades, each of which includes one or more of the other genera in this study. The resulting phylogenetic hypothesis does not match previous conclusions based on vegetative and floral morphology of the taxa involved but is congruent with isoenzyme, karyological, and chloroplast DNA restriction data. Our results indicate that floral morphology is highly flexible and current generic and infrageneric limits are artificial. Even if some floral characters closely correspond to the molecular data, most are highly homoplastic and thus unsuitable for phylogenetic reconstruction. Various traits pertaining to floral morphology may be interpreted as a result of ecological convergence related to pollinator-mediated selection; such characters can undergo drastic modifications without correspondingly dramatic genetic changes.
Base Sequence↗