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PubMed2005

[Self-evaluation of the quality of life of children aged 6 to 12 years old: analysis of the concept and development of a prototype tool].

The objective of this work was to assess the quality of life of children aged 6 to 12 years old. The authors present the different conceptual and operational steps which lead to the construction of a prototype tool. It was a generic tool composed of 63 items which covered the classically described areas of life. Its originality was due to the method of construction used which included children's involvement, to the pictorial representation of real-life situations for children, and to its adaptation for gender. The evaluation of this tool showed a good level of acceptability but statistical analysis revealed some metrological inadequacies leading to the reconsideration of the initial concepts and their methods of exploration. Therefore a new tool was constructed whose validation is presented in a second article in the next issue.

Child↗
PubMed1998

Karnofsky's score modified for cats.

The index of Karnofsky evaluating quality of life was originally developed by David A. Karnofsky in 1948. It determines the ability of a patient to carry on normal activities in life by using a scale from 0 to 100%. This index was modified for the cat. The index enables judgment of life quality and well-being in cats which is very difficult to interpret. Objectivity is given by a classification orientated in details concerning general condition as well as eating, playing, sleeping, and social behavior.

Animals↗
PubMed2002

A cardiovascular life history. A life course analysis of the original Framingham Heart Study cohort.

AIMS The objective of this paper is to measure the potential burden of cardiovascular disease within the original Framingham Heart Study cohort by transforming its well-described epidemiological measures into time-based health policy measures, such as life years lost to or lived with the disease. METHODS AND RESULTS We constructed multi-state life tables of the Framingham Heart Study cohort to calculate dwelling times with a history of cardiovascular disease. Age-specific probabilities determined transitions from healthy through disease to death. For this synthetic cohort, from age 50 men (women) live on average 26 (32) years; 20 (26) free of cardiovascular disease. Allowing occupancy of more than one disease state, 50-year-old males (females) live 2 X 9 (1 X 2) years with a history of myocardial infarction, 0 X 93 (1 X 2) with a history of stroke, and 0 X 67 (0 X 93) with congestive heart failure. Having ever suffered acute myocardial infarction, stroke or congestive heart failure, life expectancy is reduced by 9 (13), 12 (15) or 16 (16) years, respectively in 60-year-old men (women). CONCLUSIONS Transforming occurrence probabilities into time-based health measures, the prevalence of cardiovascular disease is remarkable: from age 50, 20% of remaining life expectancy is lived with the disease. Such measures are integral to appropriate health planning and assessment of the potential population health value of various treatment and prevention strategies.

Adult↗
PubMed2006

Global phylogeny determined by the combination of protein domains in proteomes.

The majority of proteins consist of multiple domains that are either repeated or combined in defined order. In this study, we survey the combination of protein domains defined at fold and fold superfamily levels in 185 genomes belonging to organisms that have been fully sequenced and introduce a method that reconstructs rooted phylogenomic trees from the content and arrangement of domains in proteins at a genomic level. We find that the majority of domain combinations were unique to Archaea, Bacteria, or Eukarya, suggesting most combinations originated after life had diversified. Domain repeat and domain repeat within multidomain proteins increased notably in eukaryotes, mainly at the expense of single-domain and domain-pair proteins. This increase was mostly confined to Metazoa. We also find an unbalanced sharing of domain combinations which suggests that Eukarya is more closely related to Bacteria than to Archaea, an observation that challenges the widely assumed eukaryote-archaebacterial sisterhood relationship. The occurrence and abundance of the molecular repertoire (interactome) of domain combinations was used to generate phylogenomic trees. These global interactome-based phylogenies described organismal histories satisfactorily, revealing the tripartite nature of life, and supporting controversial evolutionary patterns, such as the Coelomata hypothesis, the grouping of plants and animals, and the Gram-positive origin of bacteria. Results suggest strongly that the process of domain combination is not random but curved by evolution, rejecting the null hypothesis of domain modules combining in the absence of natural selection or an optimality criterion.

Animals↗
PubMed1976

The origin and evolution of protein superfamilies.

The organization of proteins into superfamilies based primarily on their sequences is introduced: examples are given of the methods used to cluster the related sequences and to elucidate the evolutionary history of the corresponding genes within each superfamily. Within the framework of this organization, the amount of sequence information currently and potentially available in all living forms can be discussed. The 116 superfamilies already sampled reflect possibly 10% of the total number. There are related proteins from many species in all of these superfamilies, suggesting that the origin of a new superfamily is rare indeed. The proteins so far sequenced are so rigorously conserved by the evolutionary process that we would expect to recognize as related descendants of any protein found in the ancestral vertebrate. The evolutionary history of the thyrotropin-gonadotropin beta chain superfamily is discussed in detail as an example. Some proteins are so constrained in structure that related forms can be recognized in prokaryotes and eukaryotes. Evolution in these superfamilies can be traced back close to the origin of life itself. From the evolutionary tree of the c-type cytochromes the identity of the prokaryote types involved in the symbiotic origin of mitochondria and chloroplasts begins to emerge.

Amino Acid Sequence↗
PubMed2004

Incorporation of nonnatural amino acids into proteins.

The genetic code is established by the aminoacylation of transfer RNA, reactions in which each amino acid is linked to its cognate tRNA that, in turn, harbors the nucleotide triplet (anticodon) specific to the amino acid. The accuracy of aminoacylation is essential for building and maintaining the universal tree of life. The ability to manipulate and expand the code holds promise for the development of new methods to create novel proteins and to understand the origins of life. Recent efforts to manipulate the genetic code have fulfilled much of this potential. These efforts have led to incorporation of nonnatural amino acids into proteins for a variety of applications and have demonstrated the plausibility of specific proposals for early evolution of the code.

Amino Acids↗
PubMedDate not supplied

Chemistry between the stars.

Life--as we know it--is a chemical process, based on water and carbon compounds. Complex organic molecules are made primarily from the biogenic elements--carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur--that formed deep within massive ancient stars. How did these elements travel from their stellar birthplaces across time and space to make up the life-form that is reading these words? In this article, we'll take a look at the chemical processes that set the stage for the origin of life.

Astronomical Phenomena↗
PubMedDate not supplied

Life forms of Pteridophyta, their origin and evolution.

The following separation of the main growth forms of Pteridophyta is proposed: thin-rhizomatous, creeping-rosetted, ascending-rosetted, vertical-rosetted, and arborescent. Each of these can be divided into life forms according to a series of morphological and other characters. The most primitive growth form of Pteridophyta is acknowledged as the thin-rhizomatous. In the course of evolution toward polymerization and integration of fronds, the group of arborescent Pteridophyta were transformed into shoot plants, initially of the Cycas type. Water ferns (Salviniaceae) and seed ferns (Pteridospermae) are known as the arbitrary type of Lycopsida which did not reach the state of shot structure of the body. In this respect, Equisetales occupy an intermediate position. It may be assumed that in the evolution of plants, the change in their life forms was of paramount significance.

Biological Evolution↗
PubMed2005

Life-history evolution and the origin of multicellularity.

The fitness of an evolutionary individual can be understood in terms of its two basic components: survival and reproduction. As embodied in current theory, trade-offs between these fitness components drive the evolution of life-history traits in extant multicellular organisms. Here, we argue that the evolution of germ-soma specialization and the emergence of individuality at a new higher level during the transition from unicellular to multicellular organisms are also consequences of trade-offs between the two components of fitness-survival and reproduction. The models presented here explore fitness trade-offs at both the cell and group levels during the unicellular-multicellular transition. When the two components of fitness negatively covary at the lower level there is an enhanced fitness at the group level equal to the covariance of components at the lower level. We show that the group fitness trade-offs are initially determined by the cell level trade-offs. However, as the transition proceeds to multicellularity, the group level trade-offs depart from the cell level ones, because certain fitness advantages of cell specialization may be realized only by the group. The curvature of the trade-off between fitness components is a basic issue in life-history theory and we predict that this curvature is concave in single-celled organisms but becomes increasingly convex as group size increases in multicellular organisms. We argue that the increasingly convex curvature of the trade-off function is driven by the initial cost of reproduction to survival which increases as group size increases. To illustrate the principles and conclusions of the model, we consider aspects of the biology of the volvocine green algae, which contain both unicellular and multicellular members.

Animals↗
PubMed2002

Genes, culture, and aging flies--what the lab can and cannot tell us about natural genetic variation for senescence.

Model organisms cultured in the lab provide a powerful way to explore basic biological processes. However, lab culture can select for high early fecundity and dramatically shorten the life-span of lab organisms. Studies that use these short-lived organisms to identify aging-related genes might identify genes that simply restore the organism's original life-span. These results might not be fully relevant to wild populations. Experiments that reduce selection for shorter life-span or seek genes in naturally long-lived cohorts should lead to a more accurate understanding of aging.

Aging↗
PubMedDate not supplied

Life history and the early origins of health differentials.

Current epidemiologic models concerning the fetal origins of later health risk are evaluated from the perspectives of evolutionary and developmental biology. Claims of adaptive value for and biological status of fetal programming are critically examined. Life history theory is applied to identify key trade-offs in adaptive strategies that constrain developmental design to use information from the environment to guide ontogeny and establish cost-benefit trade-offs that weigh early survival advantage against remote or unlikely future costs. Expectable environments of evolutionary adaptedness, particularly of gestation, are characterized and their impact on human adaptive design discussed. The roles of neuroendocrine mechanisms in scaffolding life course development, negotiating ongoing cost-benefit trade-offs, and mediating their long-term impacts on function and health are reviewed in detail. Overviews of gestational biology and the postnatal physiologic, cognitive-affective, and behavioral effects of gestational stress identify a shared central role for the hypothalamic-pituitary-adrenal (HPA) axis. Rather than merely mediating stress responses, the axis emerges an agent of resource allocation that draws a common thread among conditions of gestation, postnatal environments, and functional and health-related outcomes. The preponderance of evolutionary and developmental analysis identifies environments as agents on both sides of the health risk equation, by influencing vulnerabilities and capacities established in early and later life course development, and determining exposures and demands encountered over the life course.

Adaptation, Physiological↗
PubMed2001

[Ontogenetic origin of the human individual from his genome].

Diverse propositions about the ontogenetic origin of a live organism, specially human beings, are examined. Unambiguous and objective propositions about this origin are that a live organism is an ontogenetically programmed and integrated organisation, that the origin condition has the greater influence on other processes, that in pluricellular organisms, no organ or tissue can be considered critical to establish origins and that the origin must be established by endogenous elements. Several hypotheses about the origin of life are discarded. The integration between oocyte cytoplasm and the genetic material that it receives, that culminates in the first genome replication, is proposed as the process that gives origin to the individual. This process occurs in all living organisms.

Embryonic and Fetal Development↗
PubMedDate not supplied

Remarks on the chemical conditions on the surface of the primitive earth and the probability of the evolution of life.

The inner planets were formed from smaller objects that had no gases associated with them. These objects contained relatively small amounts of water and carbon in a form similar to that found in carbonaceous chondrites. The first forms of life must have originated during the time when the water reacted with the carbon (and also with nitrides, phosphides, etc.), while the hydrogen formed by this reaction was continuously lost from the gravitational field of the Earth. About 10-44 atoms of carbon reacted with water during less than 10-17 s. The crucial question is whether some form of life will always develop under these conditions, or whether the origin of life is an improbable, perhaps an immensely improbable event. At present it is still impossible to answer this question.

Biological Evolution↗
PubMedDate not supplied

Cultural sensitivity in end-of-life discussions.

Cultural origins influence the way patients and health care providers think about care and treatment at the end-of-life. With increasing ethnic diversity there is greater chance that clinical encounters will occur between individuals of different backgrounds, therefore there is greater risk of misunderstanding. Health care providers should be mindful of cultural differences when informing patients, discussing advance care planning, responding to requests for assistance in dying, and responding to requests for limiting treatment.

Advance Directives↗
PubMed1987

Bacterial viruses, prophages, and plasmids, reconsidered.

Prophages and plasmids offer to the bacterial cells generalized access to each other's genes. The result is an extremely rich, available gene bank. It has successfully supported the original bacterial life since its beginnings and therefore it has conditioned all bacterial cells. Thus, most of the basic mechanisms for the living world, the richest variety of new genes, and particularly the improved ways of using DNA as an extremely adaptable genetic material happened in bacteria with the help of prophages and plasmids. This fact has profoundly marked all the biosphere. The ancestor of the nucleus probably started as an accumulation of prophages and plasmids integrated in the growing "chromosome" of the outer symbiont of the first eukaryotes. Many bacterial vestiges were probably retained in eukaryotes, mostly those related to the dominant and lasting role of small replicons in all their bacterial precursors. These vestiges may, for example, serve as an endogenic source for some DNA viruses in eukaryotes. The other animal and plant viruses seem to derive directly or indirectly from prophages or plasmids. In the case of RNA viruses they may have originated from probable RNA small replicons present in the first forms of life on earth. Some confusion arose in biology, as viruses were discovered first and therefore their most probable ancestors, the plasmids and the prophages which were discovered later, were thought to be viruslike, or viruses, as is the case with prophages.

Bacteria↗
PubMed2001

;Evolution of Photosynthesis' (1970), re-examined thirty years later.

I have re-examined my 1970 article 'Evolution of Photosynthesis' (Olson JM, Science 168: 438-446) to see whether any of my original proposals still survive. My original conviction that the evolution of photosynthesis was intimately connected with the origin of life has been replaced with the realization that photosynthesis may have been invented by the Bacteria after their divergence from the Archea. The common ancestor of all extant photosynthetic bacteria and cyanobacteria probably contained bacteriochlorophyll a, rather than chlorophyll a as originally proposed, and may have carried out CO(2) fixation instead of photoassimilation. The first electron donors were probably reduced sulfur compounds and later ferrous iron. The common ancestor of all extant reaction centers was probably similar to the homodimeric RC1 of present-day green sulfur bacteria (Chlorobiaceae) and heliobacteria. In the common ancestor of proteobacteria and cyanobacteria, the gene for the primordial RC1 was apparently duplicated and one copy split into two genes, one for RC2 and the other for a chlorophyll protein similar to CP43 and CP47 in extant cyanobacteria and chloroplasts. Homodimeric RC1 and homodimeric RC2 functioned in series as in the Z-scheme to deliver electrons from Fe(OH)(+) to NADP(+), while RC1 and/or RC2 separately drove cyclic electron flow for the production of ATP. In the line of evolution leading to proteobacteria, RC1 and the chlorophyll protein were lost, but RC2 was retained and became heterodimeric. In the line leading to cyanobacteria, both RC1 and RC2 replaced bacteriochlorophyll a with chlorophyll a and became heterodimeric. Heterodimeric RC2 further coevolved with a Mn-containing complex to utilize water as the electron donor for CO(2) fixation. The chlorophyll-protein was also retained and evolved into CP43 and CP47. Heliobacteria are the nearest photosynthetic relatives of cyanobacteria. The branching order of photosynthetic genes appears to be (1) proteobacteria, (2) green bacteria (Chlorobiaceae plus Chloroflexaceae), and (3) heliobacteria plus cyanobacteria.

Journal Article↗
PubMed2001

The course of postpartum psychiatric disorders in women and their partners.

This study examined the course of postpartum psychiatric disorders in a community sample of mothers and their partners to determine whether sociodemographic variables, life stress, and psychiatric history were related to persistence of mental health problems. At 6 months postpartum, 48 index couples where the wife had a psychiatric disorder at 2 months postpartum and 50 control couples with no such diagnosis underwent diagnostic interviews and completed questionnaires on psychological symptoms, life stress, and treatment history. The results indicate that at follow-up, 54% of the index mothers still had a psychiatric diagnosis, as did 60% of their partners who had had a psychiatric diagnosis at 2 months postpartum. Socioeconomic status, country of origin, and life stress were related to persistence, as were diagnosis and timing of onset of the disorder. About a third of the parents were referred for treatment. It is concluded that for many families, postpartum psychiatric disorders are not a transient phenomenon.

Depression, Postpartum↗
PubMed2000

Longitudinal study of the influence of life events and personality status on diagnostic change in three neurotic disorders.

It has been known for many years that diagnosis within the neurotic spectrum of disorders is temporally unstable and also that life events can be major precipitants of change in symptoms. Reasons for this instability could include inherent inadequacy of current diagnostic practice, the influence of life events as an agent of diagnostic shift, and an innate course of disorder with features dependent on the stage at which disorder presents (e.g., development of panic to agoraphobia). These possibilities were examined in a prospective study that was initially a randomised controlled trial. Two hundred ten patients recruited from primary care psychiatric clinics with DSM-III diagnosed dysthymic, generalised anxiety, and panic disorders were randomly allocated to either drug treatment (mainly antidepressants), cognitive-behaviour therapy, or self-help therapy over a 2 year period, irrespective of original diagnosis. Life events were recorded by using a standard procedure over the period 6 months before starting treatment and at five occasions over 2 years; 181 (86%) of the patients had follow-up data and 76% maintained compliance with the original treatment allocated over the 2 years; and 155 of the 181 patients (86%) had at least one diagnostic change in this period. There was no difference in the number of diagnostic changes between the three original diagnostic groups, but dysthymic disorder changed more frequently to major depressive episode than did GAD or panic disorder (20; 11; 12) (%) and panic disorder changed more frequently to agoraphobia (with or without panic) than did dysthymia or GAD (18; 8; 6) (%). There was no relationship between loss events and depressive diagnoses or between addition events and anxiety diagnoses, but greater numbers of conflict events were associated with diagnostic change. More life events were associated with the flamboyant and dependent personality disorders, reinforcing other evidence that many life events are internally generated by personality characteristics and cannot be regarded as truly independent.

Cognitive Behavioral Therapy↗