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At least 127 records · Page 7Linked to original sources
PubMed1989

In vitro studies of interactions between frequent and unique mRNAs and cytoplasmic factors from brain tissue of several species of wild timber voles of northern Eurasia, Clethrionomys glareolus, Clethrionomys frater and Clethrionomys gapperi: a new criticism to a modern molecular-genetic concept of biological evolution.

As a result of the complex comparative neurochemical study of the translation machinery functioning in the brain cells of three conventionally "phylogenetically related" species of wild timber voles (Clethrionomys glareolus, Clethrionomys frater and Clethrionomys gapperi), it has been found that the cytoplasm of brain cells of the latter contain an oligonucleotide (oligoribonucleotide) factor(s) with mol. weight below 1.0 KD which is able completely and highly selectively to inhibit the translation directed by mRNA which are species-specific templates and which were isolated from analogical tissue (brain) of "closely related" organisms. This phenomenon was found for the first time using special Cell-Free Translation Systems (CFTS) of very different variants of their composition consisting of the following main components: Post-Mitochondrial Supernatant (PMS), total cytoplasmic poly(A)+ mRNA or a species-specific poly(A)+ mRNA isolated form the PMS by affinity chromatography on the columns with the anti-mRNA1-FAB-(CNBr)-Sepharose, or purified 9S or 11S globin or histone specific mRNAs, respectively, and, finally a few samples of the CFTS used contain the additions of high or low molecular weight cytosolic compounds isolated from S150 fraction by ultrafiltration on Diaflo UM2 membrane with an exclusion limit of 1.0 KD. All CFTs components listed were isolated separately from the brain tissue of each organism studied. A new complex way for construction and using of the CFTS leads to an adequately documented conclusion which suggested the existence of special, so far uncharacterized in detail, cytoplasmic oligoribonucleotide factor(s) for efficient blocking for the cytoplasmic expression of "evolutionally renovated part" of genome; i.e., these factors seem to be sufficiently powerful suppressors of the translation of every mRNA template if the latter is not usual for the cell type containing the cytoplasmic suppressors mentioned in the case of a "so-called" newly found (perhaps, due to spontaneous but nonlethal mutagenesis) genes expression at the level of mRNA functioning in the cytoplasm. All findings and ideas of the paper are under discussion.

Animals↗
PubMed1990

[Technical and biological evolution of medically assisted procreation (MAP)].

Compared to IUI (to which one knows that an ovulation induction must not be associated and where 6 cycles must not be exceeded), in vitro fertilization has undergone an important evolution. It has now become ambulatory. Its evolution has been marked by the use of LH-RH agonists, the vaginal route for the echographic puncture and freezing of the embryos. The two progresses expected are: in the short term, the mastering of the retrograde catheterization of the tube, to enable the embryo replacement in sterilities of healthy tubes and, in middle term, a better assessment of the quality of the conceptus to carry out a selective embryo transfer and to reduce the rate of multiple pregnancies.

Clomiphene↗
PubMed1979

[Clinical and biological evolution of myasthenia gravis after thymectomy in a 13-year-old girl].

A 13-year-old girl suffering from rhumatoid arthritis developed a myasthenia gravis. Her circulating anti-acetylcholine receptor antibodies were observed before and after thymectomy. Surgical removal of the thymus was followed by complete clinical remission associated with a progressive decrease of the antibody level; these antibodies did not disappear completely even as late as 2 years after the operation.

Acetylcholine↗
PubMed1977

[Clinical study and evolution of various biological parameters (Pb, ALA-D, FEP) in 14 cases after ingestion of lead containing beverages].

Clinical and biological evolution is reported in 14 individuals (adults, teenagers, children) who had ingested lead-containing beverages stored in glazed pottery. There are marked differences between adults and children regarding the half lives of lead in blood. Almost two years after the discovery of the risk, abnormal amounts of Pb, ALA-D and FEP remain in the absence of any other clinical disturbance. The hazard of glazed pottery is reemphasized.

Adolescent↗
PubMed2006

Human evolution: humanistic selection and looking to the future.

Cultural evolution has predominated over biological evolution in modern man (Homo sapiens sapiens). Cultural evolution differs from biological evolution not only by inheritance of acquired characteristics but also, as is proposed in the present essay, by another kind of selection mechanism. Whereas selection in biological evolution is executed according to a criterion of reproductive success (the natural selection), selection in cultural evolution appears to be carried out according to human and humanistic criteria (success or fitness in meeting human needs, interests and humanistic values--"humanistic selection"). Many humanistic needs or values do not seem to be prerequisite for reproductive success, yet some of them (e.g. a need for freedom) seem to be inborn. Innateness, humanistic selection (decisive at a community level) and hierarchy of some human needs, interests and values appear to give cultural evolution a generally upward trend although long periods of stagnation or even regression may occur. Modern humans appear to be still at the early stage of their cultural evolution. A further cultural evolution of man appears to be, in contrast to biological evolution, predictable (with an optimistic outlook) and testable. The problem is that the hopeful result of this test will probably be known only in the fairly remote future provided that this species will not become extinct before that.

Biological Evolution↗
PubMed2002

Errors drive the evolution of biological signalling to costly codes.

Reduction of costs in biological signalling seems an evolutionary advantage, but recent experiments have shown signalling codes shifted to signals of high cost with an underutilization of low-cost signals. Here I derive a theory for efficient signalling that includes both errors and costs as constraints and I show that errors in the efficient translation of biological states into signals can shift codes to higher costs, effectively performing a quality control. The statistical structure of signal usage is predicted to be of a generalized Boltzmann form that penalizes signals that are costly and sensitive to errors. This predicted distribution of signal usage against signal cost has two main features: an exponential tail required for cost efficiency and an underutilization of the low-cost signals required to protect the signalling quality from the errors. These predictions are shown to correspond quantitatively to the experiments in which gathering signal statistics is feasible as in visual cortex neurons.

Animal Communication↗