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At least 19 recordsLinked to original sources
PubMed1988

Comparative evolution: latent potentials for anagenetic advance.

One of the principles that has emerged from experimental evolutionary studies of microorganisms is that polymorphic alleles or new mutations can sometimes possess a latent potential to respond to selection in different environments, although the alleles may be functionally equivalent or disfavored under typical conditions. We suggest that such responses to selection in microorganisms serve as experimental models of evolutionary advances that occur over much longer periods of time in higher organisms. We propose as a general evolutionary principle that anagenic advances often come from capitalizing on preexisting latent selection potentials in the presence of novel ecological opportunity.

Animals↗
PubMed1985

Compared evolution of plasma fibronectin and angiotensin-converting enzyme levels in septic ARDS.

Serum angiotensin converting enzyme (serum ACE) levels and plasma fibronectin levels were measured daily in 46 septic patients during a ten day period. Thirty-eight patients developed ARDS; 28 survived (group 1), ten died (group 2), eight patients had no features of ARDS and survived (group 3). Sequential measurements of ACE and fibronectin levels were compared and plotted against indexes of respiratory impairment: PaO2 max Qs/Qt, static compliance and VD/VA ratio. These indexes were taken as criteria of weaning from controlled ventilation. During ARDS (groups 1 and 2), serum ACE levels decreased and were closely correlated with the severity of lung injury. Persistently decreased levels after eight days were consistent with continuing injury or lack of endothelial repair. On the other hand, plasma fibronectin levels increased throughout the study in survivors (group 1 and 3) and decreased in the group with fatal ARDS only (group 2). These results indicate that serum ACE levels might be a good index of endothelial injury and repair during ARDS and fibronectin a better index for evolution of sepsis and vital prognosis.

Fibronectins↗
PubMed1992

Crypthecodinium and Tetrahymena: an exercise in comparative evolution.

Nucleotide sequences have been determined for the highly variable D2 region of the large rRNA molecule for over 60 strains of dinoflagellates. These strains were selected from a worldwide collection that represents all the known sibling species (compatibility groups, Mendelian species) in the sibling swarm referred to as Crypthecodinium cohnii. A phylogenetic tree has been constructed from an analysis of the variations in a length of about 180 bases, using PHYLOGEN string analysis programs. The Crypthecodinium tree is compared with the previously published but here augmented tree constructed upon the same rRNA region for the sibling species of a worldwide collection of ciliated protozoa related to the genus Tetrahymena. The first reported sequence of Lambornella clarki, the parasite of tree-hole mosquitoes, is included. The dinoflagellate species complex is much more homogeneous with respect to ribosomal variation. The mean number of differences among sequences from different Crypthecodinium species is about 7, in comparison with 22 differences among the ciliate species examined. Moreover, all the diversity in the dinoflagellates can be explained by base substitutions, whereas insertions and deletions are common in the ciliates. The dinoflagellates are also much more uniform with respect to nutritional and genetic economies. The two complexes differ also in the relationship between molecular variations and breeding compatibility. All tetrahymenine sibling species thus far examined are monomorphic in the D2 region, but several dinoflagellate species are polymorphic. Several different dinoflagellate species, moreover, have identical D2 regions. This kind of ribosomal identity of incompatible strains is found in these ciliates only in one tight cluster of species--Group C. The tetrahymenine swarm is apparently much older than the Crypthecodinium swarm, and the dinoflagellate species produce incompatible progeny species much more readily than do the ciliates, perhaps by the acquisition of mutations that potentiate incompatibility in sympatric populations.

Animals↗
PubMed1992

Comparative evolution of mipafox-induced delayed neuropathy in rats and hens.

Adult male Long-Evans rats and White Leghorn hens were given 30 mg/kg mipafox ip. Administration of this organophosphorus ester resulted in > or = 89% inhibition of brain and spinal cord neurotoxic esterase activity in both species 4 hr after dosing. Our sequential, comparative study of the bilateral mipafox-induced neuropathy in the medulla and cervical spinal cord in hens and rats demonstrated that the rats had well-developed, vacuolar axonopathic lesions in the fasciculus gracilis by post-dosing day 7. Severely affected rats with such lesions were noted through day 21, but not subsequently (days 28 and 35). The hen had a slower developing, but more severe, consistent and longer lasting neuropathy than the rat. In these birds, lesions in the medulla and rostral cervical spinal cord levels were more extensive, involving large regions of both the spinocerebellar tracts and fasciculus gracilis. Neuropathic changes, including myelinated fiber axonopathy and Wallerian-like degeneration, were prominent from days 14 - 35 in hens, and were associated with prominent gliosis in the later stages.

Animals↗
PubMed1992

Comparative evolution of P-M system and infection by the sigma virus in French and Spanish populations of Drosophila melanogaster.

In 1983, an extensive survey of populations of D. melanogaster was started in a southern French region (Languedoc) in two non-Mendelian systems: the P-M system of transposable elements and the hereditary Rhabdovirus sigma. Unexpectedly fast-evolving phenomena were observed and interesting correlations were noted, giving similar geographical pattern to the region in both systems. For these reasons, the analysis was continued and extended towards the north (Rhône Valley) and the south (Spain). In the P-M system, all the Languedoc populations evolved from 1983 to 1991 towards the Q type which is characteristic of the Rhône Valley populations. In contrast, M' strains are currently observed in the southernmost French populations and in all Spanish ones, so that there is a clear pattern in their geographical distribution. The frequency of flies infected by the sigma virus dramatically increased from 1983 to 1988 in Languedoc; this increase was clearly correlated with some viral characteristics. But, in northern France, similar characteristics did not trigger any increase in the frequency of infected flies. The data presented here show that the distinctive features of Languedoc extend northwards through the Rhône Valley up to Lyon and disappears southwards before the Spanish border.

Alleles↗
PubMed1992

Morphology, behavior, and evolution: comparative kinematics of aquatic feeding in salamanders.

The kinematics of aquatic prey capture were studied in species representing six salamander families (Ambystomatidae, Amphiumidae, Cryptobranchidae, Dicamptodontidae, Proteidae, and Sirenidae) to test the hypothesis that the process of aquatic prey capture is similar in these families. Seven variables were digitized from high-speed video records of prey capture, and a nested analysis of variance was performed to test for both significant individual within taxon and among taxa effects. The time-to-peak head angle and gape variables showed no taxon effect, while the other five variables exhibited highly significant differences among taxa. Cryptobranchus and Siren showed the most divergent kinematic pattern from the other taxa in a multivariate analysis of all variables, while Ambystoma, Dicamptodon, and Amphiuma tended to have similar overall patterns of head movement. These results show that kinematic patterns during aquatic feeding are not conserved across salamander taxa, and that phylogenetic differentiation in head morphology has been accompanied by novelties in feeding function. The feeding mechanisms of Cryptobranchus and Amphiuma have a bidirectional hydrodynamic design with kinematic correlates that are similar to kinematic characteristics of aquatic feeding in turtles and transformed ambystomatid salamanders. A general framework is presented as an aid to understanding the interrelationships among muscle activity patterns, morphology, and behavior (kinematic patterns). By considering the distribution of taxa in three multivariate spaces, corresponding to three of the levels at which one might analyze a behavior (kinematics, morphology, and motor pattern), it is possible to identify patterns of correspondence among the levels, which aid in understanding the evolution of behavior.

Animals↗
PubMedDate not supplied

[Aging and atherosclerosis of human aorta. Comparative evolution of seven glycosyl-transferases and of lactate-dehydrogenase (author's transl)].

Seven glycosyl-transferases and the lactico-dehydrogenase from human aortas were assayed. These aortas were divided in five classes according to the age and in five steps according to the atherogenesis. These enzymic activities do not show any parallelism in their evolution; their variation with age and with atherogenesis is quite different. For example, the N-acetylgalactosaminyl-transferase activity increases with atherogenesis whereas it diminishes with age; on the other hand the lactate-dehydrogenase activity increases with age and decreases with atherogenesis; the sialyl-transferase activity is nearly constant during adulthood while it hardly declines with atherogenesis. These assays suggest: 1) an effect of energy metabolism on the glycosyl-transferase activities; 2) a qualitative and quantitative variation of the glycosaminoglycans biosynthesis; 3) a structural modification of the glucidic part of the glycoproteins which can induce the formation of antigenic sites.

Adolescent↗
PubMed1975

[Comparative evolution of blood antibodies in cattle infested with hypodermosis and treated with different insecticides (author's transl)].

Immunological response to hypodermosis is studied by a passive hemagglutination method in three groups of cattle naturally infested during the spring of 1972. In the autumn, one group was treated with fenthion and another with niclofolan, a drug generally used for distomatosis, but also efficient in hypodermosis and free from side-effects. The third group served as a control. Two kinds of immunological response are observed after use of the insecticide. In the group treated with fenthion, there is a rapid drop in antibodies during the 3 days following treatment; this increases for the next 2 months up to a very low level, which is stable for 3 months (fig. 3, 4, 5). During the same period, antibodies in the control group increase regularly to reach a maximum in April or May (fig. 1, 2). The immunological response of the host is closely related to the antigenic stimulation of the larvae. In the group treated with niclofolan, the slow drop in antibodies suggests that there is a parallel drop in the number of larvae during the month following treatment. A study of the other group shows that larvae are affected in the 24 hours following fenthion administration. This agent, as well as all organophosphorous compounds, are well-known to act efficiently on larvae and have anaphylactic-type side-effects on the host. The massive degradation of larvae should have induced an important antigenic reaction, but no increase in the antibodies of the host is observed; there is a even rapid drop in the number of larvae immediately after treatment. This fact is investigated further by experiments on guinea pig: the role of antigen-antibody complexes is studied by passive anaphylaxis. It appears that shock reactions, following use of organophosphorous insecticides, have a true-hyper-sensitivity origin, and are increased by the intrinsic toxicity of the first instar larvae.

Animals↗
PubMedDate not supplied

[Evolution of the neocortex. The principle of a double afferent supply in mammalian evolution].

Comparative electrophysiological data are presented on the role of thalamic, hypothalamic and hippocampal structures in organization and activity of different neocortical formations at various steps of evolution. It was shown that higher mammals have double afferent supply of associative zones of the new cortex from the thalamic and hypothalamic nuclei, exhibiting significant increase in the degree of their convergence pattern.

Afferent Pathways↗
PubMed1991

[Mixed mullerian tumours of the endometrium. Retrospective study, with prognostic aims, comparing their evolution to that of adenocarcinomas of the endometrium].

Mixed Mullerian Tumours (MMT) of the endometrium have a bad reputation as far as prognosis is concerned. We have studied 34 cases of MMT treated between 1976 and 1988 and have compared their outcome with a matched series of 68 cases of adenocarcinoma (ADC). These were taken out of 880 cases of ADC treated during this period of time after matching them for the stage, the type of treatment, the year of treatment and the age of the patient. The curves of survival and the totals of survival were determined using Kaplan-Meier's method and also compared using Logrank's test. The 5-years overall survival was 18% for MMT as against 55% for ADC (p less than 0.001). The difference was equally significant statistically in terms of specific survival without recurrences. The 16 patients in stages I and II who were treated with the same protocol as used for ADC were matched against 32 cases of ADC taken out of the 680 cases ADC in stages I and II and treated by the same protocol (84%). After five years MMT had a higher number of survivors (35% overall, 45% with specific survival and 35% without recurrences), but the difference with survival of ADC was as significant (respectively 75, 85, 85%). Recurrences of MMT were frequent (62%), with metastases in 9 out of 10 and early (50%), in every respect opposed with recurrences of ADC (16%) which were in three out of five cases localized and late (after 10 months). These figures make one have to think of modifying the way MMT is treated. External pelvic radiotherapy should be carried out before any other treatment. The place for other methods of therapy is to be discussed.

Adenocarcinoma↗