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PubMedDate not supplied

Relationship between serum total sialic acid and C-reactive protein in silicosis.

Serum total sialic acid and C-reactive protein (CRP) were studied in 68 patients with silicosis divided into 3 groups according to the evolutive stage of disease. The results were compared with the data obtained in a control group of 35 healthy subjects. The changes in serum total sialic acid levels were in parallel with those of CRP in silicosis. Patients in stage III had the highest mean values of serum total sialic acid (p < 0.01) and of CRP (p < 0.001). Linear regression analysis revealed a close positive correlation between serum total sialic acid and CRP levels in silicosis (r = 0.86, p < 0.01).

Adult↗

PubMed2006

Geographic structure of pollinator communities, reproductive assurance, and the evolution of self-pollination.

Reproductive assurance is often invoked as an explanation for the evolution of self-fertilization in plants. However, key aspects of this hypothesis have received little empirical support. In this study, I use geographic surveys of pollinator communities along with functional studies of floral trait variation to examine the role of pollination ecology in mating system differentiation among populations and subspecies of the annual plant Clarkia xantiana. A greenhouse experiment involving 30 populations from throughout the species' range indicated that variation in two floral traits, herkogamy and protandry, was closely related to levels of autofertility and that trait variation was partitioned mainly among populations. Emasculation experiments in the field showed that autonomous selfing confers reproductive assurance by elevating fruit and seed production. Surveys of pollinator communities across the geographic range of the species revealed that bee pollinator abundance and community composition differed dramatically between populations of the outcrossing subspecies xantiana and the selfing subspecies parviflora despite their close proximity. Specialist bee pollinators of Clarkia were absent from selfing populations, but they were the most frequent visitors to outcrossing populations. Moreover, within the outcrossing subspecies xantiana, there was a close correspondence between specialist abundance and population differentiation in herkogamy, a key mating system trait. This spatial covariation arose, in part, because geographically peripheral populations had reduced herkogamy, higher autofertility, and lower pollinator abundance compared to central populations of xantiana. Finally, I detected strong spatial structure to bee communities both across the range of the species and within the outcrossing subspecies. In both cases, spatial structure was stronger for specialist bees compared to generalist bees, and pollinator communities varied in parallel with population variation in herkogamy. These results provide evidence that mating system differentiation parallels spatial variation in pollinator abundance and community composition at both broad and more restricted spatial scales, consistent with the hypothesis that pollinator abundance and reproductive assurance are important drivers of plant mating system evolution.

Adaptation, Biological↗

PubMed2006

The Mediterranean diet in a world context.

OBJECTIVE: To put the debate on the Mediterranean diet in context by highlighting historical and prospective changes in the level and composition of food consumption in the world and key Mediterranean countries. DESIGN: Data from FAO's food balance sheets are used to illustrate historical evolution. Projections to 2030 are presented from FAO's recent and ongoing work on exploring world food and agriculture futures. SETTING: International. RESULTS AND CONCLUSIONS: Many developing countries are undergoing diet transitions bringing them closer to the diets prevalent in the richer countries, i.e. with more energy-dense foods. There follows an increase in the incidence of diet-related non-communicable diseases, which are superimposed on the health problems related to undernutrition that still afflict them. In parallel, many low-income countries are making little progress towards raising food consumption levels necessary for good nutrition and food security. Wider adoption of food consumption patterns akin to those of the Mediterranean diet hold promise of contributing to mitigate adverse effects of such diet transitions. However, the evolution of food consumption in the Mediterranean countries themselves is not encouraging, as these countries have also followed the trend towards higher shares of energy-dense foods. Possible policy responses to these problems include measures to raise awareness of the benefits of healthier diets and/or to change relative food prices in favour of such diets (by taxing fattening foods) or, at the extreme, making individuals who follow 'bad' diets, and thus are prone to associated diseases, bear a higher part of the consequent costs borne by the public health systems (tax fat people).

Developing Countries↗

PubMed2006

Chromosomal evolution of elements B and C in the Sophophora subgenus of Drosophila: evolutionary rate and polymorphism.

The locations of 77 markers along the chromosomal elements B (41 markers) and C (36 markers) of Drosophila subobscura, D. pseudoobscura, and D. melanogaster were obtained by in situ hybridization on polytene chromosomes. In comparisons between D. subobscura and D. pseudoobscura, 10 conserved segments (accounting for 32% of the chromosomal length) were detected on element B and eight (17% of the chromosomal length) on element C. The fixation rate of paracentric inversions inferred by a maximum likelihood approach differs significantly between elements. Muller's element C (0.17 breakpoints/Mb/million years) is evolving two times faster than element B (0.08 breakpoints/Mb/million years). This difference in the evolutionary rate is paralleled by differences in the extent of chromosomal polymorphism in the corresponding lineages. Element C is highly polymorphic in D. subobscura, D. pseudoobscura, and in other obscura group species such as D. obscura and D. athabasca. In contrast, the level of polymorphism in element B is much lower in these species. The fixation rates of paracentric inversions estimated in the present study between species of the Sophophora subgenus are the highest estimates so far reported in the genus for the autosomes. At the subgenus level, there is also a parallelism between the high fixation rate and the classical observation that the species of the Sophophora subgenus tend to be more polymorphic than the species of the Drosophila subgenus. Therefore, the detected relationship between level of polymorphism and evolutionary rate might be a general characteristic of chromosomal evolution in the genus Drosophila.

Animals↗

PubMed1996

[Features and evolution of postoperative pain in patients undergoing thoracotomy].

We examined in this perspective study 30 patients (15 males and 15 females) who undergone classic thoracotomy for lung or mediastinal diseases, without postoperative complications. Intensity and different qualitative components of postoperative pain have been evaluated in the 1st, 3rd, 5th, the day after last pleural drainage removal and 2 months after the operation. All patients answered a schedule adherent to Questionario Italiano del Dolore (QUID). Pain became less intense chiefly with drainage removal with the same time trend for both sex (parallel curves). Pain is probably stronger in women. From a qualitative point of view, the sensorial component is the same in both sexes. Affective and evaluative component is greater in women: in other words, women realize more than men the painful stimulus and are more troubled. A computerized analysis of answers to a questionnaire like QUID or, better, its evolution, may be helpful for a more effective pharmacological choice between pure analgesics, sedative analgesics and ataractic drugs.

Analgesics↗

PubMedDate not supplied

[Morphogenesis of the genital system in the superfamily Tylenchoidea (Nematoda)].

Morphogenesis of the genital system of 14 species of nematodes of the superfamily Tylenchoidea was studied. The evolution of the genital system of females in the superfamily was considered. The initial type for the group is a paired gonade of the females. In different families the reduction of the hind branch of the gonade proceeds in parallel. During ontogenesis the development of the posterior part of the trophicogenital department and the gonade branch restrains. In the family Pratylenchidae this phenomenon is associated with the shortening of the body during the transition to endoparasitism; in the family Tylenchidae the phenomenon is connected with the acquiring of the streamline form suitable for living in humid biotopes. In the family Anguinidae takes place the hypertrophy of the female genital system connected with the transition to the cavitary endoparasitism. A new technique for making preparations of nematodes is suggested.

Biological Evolution↗

PubMed2003

Cardiac chamber formation: development, genes, and evolution.

Concepts of cardiac development have greatly influenced the description of the formation of the four-chambered vertebrate heart. Traditionally, the embryonic tubular heart is considered to be a composite of serially arranged segments representing adult cardiac compartments. Conversion of such a serial arrangement into the parallel arrangement of the mammalian heart is difficult to understand. Logical integration of the development of the cardiac conduction system into the serial concept has remained puzzling as well. Therefore, the current description needed reconsideration, and we decided to evaluate the essentialities of cardiac design, its evolutionary and embryonic development, and the molecular pathways recruited to make the four-chambered mammalian heart. The three principal notions taken into consideration are as follows. 1) Both the ancestor chordate heart and the embryonic tubular heart of higher vertebrates consist of poorly developed and poorly coupled "pacemaker-like" cardiac muscle cells with the highest pacemaker activity at the venous pole, causing unidirectional peristaltic contraction waves. 2) From this heart tube, ventricular chambers differentiate ventrally and atrial chambers dorsally. The developing chambers display high proliferative activity and consist of structurally well-developed and well-coupled muscle cells with low pacemaker activity, which permits fast conduction of the impulse and efficacious contraction. The forming chambers remain flanked by slowly proliferating pacemaker-like myocardium that is temporally prevented from differentiating into chamber myocardium. 3) The trabecular myocardium proliferates slowly, consists of structurally poorly developed, but well-coupled, cells and contributes to the ventricular conduction system. The atrial and ventricular chambers of the formed heart are activated and interconnected by derivatives of embryonic myocardium. The topographical arrangement of the distinct cardiac muscle cells in the forming heart explains the embryonic electrocardiogram (ECG), does not require the invention of nodes, and allows a logical transition from a peristaltic tubular heart to a synchronously contracting four-chambered heart. This view on the development of cardiac design unfolds fascinating possibilities for future research.

Animals↗

PubMed2005

Plant genome analysis: the state of the art.

Plants are the basis for the survival of all "higher" organisms on Earth. Development of molecular genetics tools has allowed analysis of the structure, evolution, and function of whole plant genomes, rather than individual genes. DNA-based markers were instrumental in constructing detailed genetic maps of model plants and all major crop species. These molecular maps were the basis of physical maps and the first plant whole genome sequences. Comparative analysis based on genetic, cytogenetic, and physical maps and DNA sequence information provided new insights into the evolution of plant nuclear and organellar genomes. Mapping factors controlling Mendelian and quantitative traits made possible the cloning and functional characterization of novel genes, which function in plant development, adaptation to biotic and abiotic stress, or in the formation of other agronomic characters. The parallel analysis of all transcripts, proteins, and metabolites present in plant cells or tissues has generated information that may lead to a better integrated understanding of genome function. Postfunctional analysis of natural variation of gene function and its effects on phenotype is envisaged to provide new diagnostic and therapeutic molecular tools for applications in plant breeding, adaptation, and ecology.

DNA, Plant↗

PubMed2000

Evolution of placentation among squamate reptiles: recent research and future directions.

Squamate reptiles are uniquely suited to study of evolution of reproductive mode and pattern of embryonic nutrition. Viviparous species have evolved from oviparous ancestors on numerous occasions, patterns of nutritional provision to embryos range widely from lecithotrophy, at one end of a continuum, to placentotrophy at the other, and structure and function of the maternal-embryonic relationship is highly constrained resulting in parallel evolutionary trajectories among taxa. Embryos of oviparous species primarily receive nourishment from yolk, but also mobilize a significant quantity of calcium from the eggshell. Most viviparous species also are predominantly lecithotrophic, yet all viviparous species are placentotrophic to some degree. Similarities in embryonic development and nutritional pattern between oviparous species and most viviparous species suggest that the pattern of nutrition of oviparous squamates is an exaptation for the evolution of viviparity and that placentotrophy and viviparity evolve concomitantly. The few species of squamates that rely substantially on placentotrophy have structural modifications of the interface between the embryo and mother that are interpreted as adaptations to enhance nutritional exchange. Recent studies have extended understanding of the diversity of embryonic nutrition and placental structure and have resulted in hypotheses for transitions in the evolution of placentotrophy, yet data are available for few species. Indirect tests of these hypotheses, by comparison of structural-functional relationships among clades in which viviparity has evolved, awaits further study of the reproductive biology of squamates.

Animals↗

PubMed1996

Elevated serum aminoterminal procollagen type-III-peptide parallels collagen accumulation in rats with secondary biliary fibrosis.

BACKGROUND/AIMS: The aminoterminal procollagen type-III-peptide, which can be released during collagen type III deposition, has been suggested as a serum marker of fibrogenesis in patients with chronic liver disease. However, longitudinal studies correlating procollagen type-III-peptide concentrations in serum with the evolution of liver fibrosis are still needed. The purpose of the present study was to prove the significance of procollagen type-III-peptide concentrations in serum as a non-invasive marker of liver fibrogenesis in an animal model that best resembles progressive human liver fibrosis. METHODS: In 88 female Wistar rats the biliary system was occluded by double ligation of the choledochal duct followed by retrograde injection of a mixture of prolamine/ethanole (Ethibloc). Sixteen rats served as controls. Groups of 8-10 rats were sacrificed at days 2, 7, 14, 21, 30, 32, 35, 60 and 90 after bile duct occlusion. In the groups histological staging (fibrosis score), determination of total liver hydroxyproline, measurement of serum procollagen type-III-peptide and routine liver function tests were performed. RESULTS: First histological signs of liver fibrosis were seen as early as 7 days after bile duct occlusion. Progressive fibrosis was paralleled by an increase of serum procollagen type-III-peptide. There was a significant correlation between serum procollagen type-III-peptide and histological stages of fibrosis (r = 0.80; p < 0.0001) as well as between serum procollagen type-III-peptide and hydroxyproline in total liver tissue (r = 0.85; p < 0.0001) CONCLUSIONS: These results indicate that: (1) complete bile duct occlusion in rats produces progressive hepatic fibrosis resembling human secondary biliary fibrosis, and (2) procollagen type-III-peptide concentrations in serum reflect ongoing collagen formation in the liver unrelated to serum markers of cholestasis and inflammation.

Animals↗

PubMed2004

Evolution of dietary specialization and chemical defense in poison frogs (Dendrobatidae): a comparative analysis.

Defensive mechanisms, including noxious or toxic substances, are favored by predation-driven natural selection. The acquisition of noxious/toxic substances can be either endogenous, in which the substances are produced by the organism, or exogenous, in which the substances are produced by another organism and are sequestered. Evidence indicates that the defensive skin alkaloids of Neotropical poison frogs (Dendrobatidae) have an exogenous source: a diet of ants and other small alkaloid-containing arthropods, which we term the diet-toxicity hypothesis. A critical prediction of the diet-toxicity hypothesis is that independent origins of dietary specialization will be found to be correlated with independent origins of skin alkaloids. We tested this prediction in an integrated framework using comparative methods with new and published data on feeding ecology and chemical defense for 15 species of dendrobatids in five genera. We found a significant correlation between alkaloid profiles and degree of dietary specialization. This reveals a recurring association of dietary specialization and alkaloid sequestration in dendrobatids, which suggests parallel evolutionary trends in the origins of defensive mechanisms.

Alkaloids↗

PubMed2005

Variability of ribosomal RNA genes in Rauwolfia species: parallelism between tissue culture-induced rearrangements and interspecies polymorphism.

An analysis of 18S-25S and 5S rRNA genes in intact plants and cultured tissues of some Rauwolfia species was performed to compare these sequences variability occurred as a result of the species evolution in nature and that induced by tissue culture. The restriction fragment length polymorphism of 18S-25S and 5S rDNA was found both in intact plants of various Rauwolfia species and in long-term Rauwolfia serpentina tissue cultures. In addition, changes in the amount of 18S-25S rRNA genes were observed in long-term R. serpentina tissue cultures. The results demonstrate that rDNA variability observed in intact plants as well as in long-term cultures is attributed to differences in the same regions of ribosomal RNA genes.

DNA, Ribosomal↗

PubMed2001

Magnetic order in the Ising model with parallel dynamics.

It is discussed how the equilibrium properties of the Ising model are described by an Hamiltonian with an antiferromagnetic low temperature behavior if only an heat bath dynamics, with the characteristics of a Probabilistic cellular automaton, is assumed to determine the temporal evolution of the system.

Journal Article↗

PubMed2005

Independent recruitment of a conserved developmental mechanism during leaf evolution.

Vascular plants evolved in the Middle to Late Silurian period, about 420 million years ago. The fossil record indicates that these primitive plants had branched stems with sporangia but no leaves. Leaf-like lateral outgrowths subsequently evolved on at least two independent occasions. In extant plants, these events are represented by microphyllous leaves in lycophytes (clubmosses, spikemosses and quillworts) and megaphyllous leaves in euphyllophytes (ferns, gymnosperms and angiosperms). Our current understanding of how leaves develop is restricted to processes that operate during megaphyll formation. Because microphylls and megaphylls evolved independently, different mechanisms might be required for leaf formation. Here we show that this is not so. Gene expression data from a microphyllous lycophyte, phylogenetic analyses, and a cross-species complementation experiment all show that a common developmental mechanism can underpin both microphyll and megaphyll formation. We propose that this mechanism might have operated originally in the context of primitive plant apices to facilitate bifurcation. Recruitment of this pathway to form leaves occurred independently and in parallel in different plant lineages.

Antirrhinum↗

PubMed1993

Non-discrete biomolecular computing: an approach to computational complexity.

General principles of information processing at the molecular level inherent in simple biological and biomolecular entities can be used to elaborate essentially new non-discrete information-processing devices. These principles are: giant parallelism of information processing; processing mechanisms based on complicated non-linear dynamics; high efficiency of information transformations; considerable behavioral complexity of computational (pseudoelementary) primitives; and the possibility of variation and evolution of the molecular components of information-processing devices, including the possibility of evolutionary learning. Problems of high computational complexity are currently of great practical importance. Non-discrete biomolecular information-processing devices seem to be able to solve effectively some classes of problems of high computational complexity.

Biomedical Engineering↗

PubMed1999

Rule-based programming paradigm: a formal basis for biological, chemical and physical computation.

A rule-based programming paradigm is described as a formal basis for biological, chemical and physical computations. In this paradigm, the computations are interpreted as the outcome arising out of interaction of elements in an object space. The interactions can create new elements (or same elements with modified attributes) or annihilate old elements according to specific rules. Since the interaction rules are inherently parallel, any number of actions can be performed cooperatively or competitively among the subsets of elements, so that the elements evolve toward an equilibrium or unstable or chaotic state. Such an evolution may retain certain invariant properties of the attributes of the elements. The object space resembles Gibbsian ensemble that corresponds to a distribution of points in the space of positions and momenta (called phase space). It permits the introduction of probabilities in rule applications. As each element of the ensemble changes over time, its phase point is carried into a new phase point. The evolution of this probability cloud in phase space corresponds to a distributed probabilistic computation. Thus, this paradigm can handle tor deterministic exact computation when the initial conditions are exactly specified and the trajectory of evolution is deterministic. Also, it can handle probabilistic mode of computation if we want to derive macroscopic or bulk properties of matter. We also explain how to support this rule-based paradigm using relational-database like query processing and transactions.

Algorithms↗

PubMed2001

Atypical "benign" partial epilepsy of childhood or pseudo-lennox syndrome. Part II: family study.

Atypical benign partial epilepsy of childhood (ABPE = Pseudo-Lennox syndrome) shows semiologic parallels to Lennox-Gastaut syndrome, however--besides the lack of tonic seizures--it has an entirely different etiology and prognosis. Recently Hahn et al [17] investigated the long-term evolution of 43 cases with ABPE. Symptomatology, EEG findings, and course were found to overlap with Rolandic epilepsy, Landau-Kleffner syndrome and ESES. The incidence of seizures in relatives was determined in the whole series investigated by Hahn et al [17]. Five of 56 siblings suffered from seizures (3 Rolandic seizures; one febrile convulsions; one unclassified). Three fathers reported grand mal. In 29 families of the series of Hahn et al EEG recordings were performed: 22 brothers, 19 sisters and 16 pairs of parents. In 29% of the siblings a sharp wave focus was demonstrable. The rate rose to 40% when only siblings investigated at the age of maximum expression (3 to 10 years) were considered. Sharp wave foci were mostly multifocal and indistinguishable from those observed in siblings of children with Rolandic epilepsy. Photoparoxysmal response and generalized spikes and waves during rest and hyperventilation were also found to be significantly elevated (26% and 13% respectively). We conclude that ABPE is a subgroup of idiopathic partial epilepsy of childhood (representing a less benign part of a spectrum) that has to be ranked in a continuum with Rolandic epilepsy. The different clinical phenotype might be caused by a higher expressivity of the identical genetic trait, possibly facilitated by other genetic or acquired factors. Genetic heterogeneity represents another possibility.

Adult↗

PubMed1997

Evolution of computer-based information systems and networks to support integrated health care delivery systems.

As health care delivery systems become more integrated with an emphasis on community wellness and prevention, well-developed information infrastructures will be needed to support their activities. The article introduces several previously published independent models for the evolution of integrated delivery systems, computer-based patient records (CPRs), and health information networks as well as a summary model that illustrates the relationship among these entities and their somewhat parallel development.

Chronic Disease↗