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PubMed2001

Arthropod phylogeny based on eight molecular loci and morphology.

The interrelationships of major clades within the Arthropoda remain one of the most contentious issues in systematics, which has traditionally been the domain of morphologists. A growing body of DNA sequences and other types of molecular data has revitalized study of arthropod phylogeny and has inspired new considerations of character evolution. Novel hypotheses such as a crustacean-hexapod affinity were based on analyses of single or few genes and limited taxon sampling, but have received recent support from mitochondrial gene order, and eye and brain ultrastructure and neurogenesis. Here we assess relationships within Arthropoda based on a synthesis of all well sampled molecular loci together with a comprehensive data set of morphological, developmental, ultrastructural and gene-order characters. The molecular data include sequences of three nuclear ribosomal genes, three nuclear protein-coding genes, and two mitochondrial genes (one protein coding, one ribosomal). We devised new optimization procedures and constructed a parallel computer cluster with 256 central processing units to analyse molecular data on a scale not previously possible. The optimal 'total evidence' cladogram supports the crustacean-hexapod clade, recognizes pycnogonids as sister to other euarthropods, and indicates monophyly of Myriapoda and Mandibulata.

Animals↗

PubMed1999

Guidelines for arterial hypertension: the echocardiography controversy.

While the recent evolution of guidelines for arterial hypertension also includes the need to evaluate coexistent cardiovascular risk factors and target organ damage in the base work-up for arterial hypertension, it does not include echocardiography systematically, because there is no evidence that information on LV geometry and function can modify management strategy in every circumstance, and there is concern about the technical variability of repeated echocardiographic examinations in the individual patient. The present issue of the Journal publishes a paper showing that adherence to the 1993 World Health Organization - International Society of Hypertension recommendations leaves untreated a proportion of patients with 'mild hypertension' who instead would have been treated if decision was also based on echocardiographic information on LV geometry. These findings challenge the most recent positions of national Societies, reserving the indication for echocardiography to patients with high risk (the vast majority). The present study appears indeed to reinforce the notion that echocardiographic examination might be very important in patients in whom, based on guidelines adherence, no pharmacological treatment would be required, whereas, based on the present evidence, echocardiographic information might be less important and perhaps superfluous for decision making in patients assigned to a high risk score, for whom aggressive treatment has been already scheduled.

Antihypertensive Agents↗

PubMed1996

Multiple roles of carbonic anhydrase in cellular transport and metabolism.

Carbonic anhydrase (CA) is a central enzyme to both transport and metabolic processes at the cellular level. In metabolically active tissue such as muscle, CA in the cytoplasm and on the sarcolemma appears to be important in facilitating CO2 transport out of the cell. Membrane-associated CA, with an extracellular orientation, also appears to be important in acidifying the outer boundary layer through the catalyzed hydration of excreted CO2. This facilitates cellular ammonia transport by providing H+ ions for the protonation of NH3, thus maintaining the trans-membrane NH3 gradient. Mitochondrial CA is known to supply HCO3- for the initial reactions of gluconeogenesis and ureagenesis in mammalian tissues, but systematic comparative studies of CA as a metabolic enzyme are lacking. CA probably evolved as an enzyme of trans-membrane facilitated CO2 transport and took on a secondary metabolic role later in metazoan evolution.

Animals↗

PubMed2001

[Diabetic foot: a public health problem too often underestimated. Consequences and therapeutic possibilities].

The clinical screening of diabetic patients at risk for foot ulcer should be regularly performed by all physicians and health professionals in charge of these patients. In addition, the high risk patient should be also educated to detect high risk foot lesions. This step represents the first strategy in order to prevent this too frequent complication of diabetes mellitus. The amputation which represents the most dramatic evolution of foot ulcer, has profound psychosocial, economic and functional effects on diabetic patients. For these reasons a global strategy should be developed in order to reduce the incidence of diabetic foot ulcer. A systematic follow-up strategy in high risk patients is highly recommended. The patient education is one of the most important step for the success of this strategy.

Amputation, Surgical↗

PubMed1991

Role of 5 alpha-reductase inhibitors in the treatment of advanced prostatic carcinoma.

Everything we know about the biology of the prostate supports the concept that DHT is the obligate androgen responsible for normal and hyperplastic growth. Whether this selectivity is maintained during malignant transformation is unknown. The consistent emergence of androgen-insensitive disease highlights the spectrum of biologic evolution this cancer is capable of. If the tumor is dependent only on DHT for neoplastic growth, the unique characteristics of a 5 alpha-reductase inhibitor offer several potential actions that warrant a systematic evaluation.

5-alpha Reductase Inhibitors↗

PubMedDate not supplied

[Ribonucleases and proteins related to it, as well as ribonuclease inhibitors of proteinaceous nature].

The recent discovery of unexpected functional diversity of different RNA molecules and some products of their degradation renewed the interest in ribonucleases. This review mainly presents recent systematized data on animal ribonucleases, including pyrimidine-specific ribonucleases, angiogenin, eosinophil-derived neurotoxin, eosinophil cationic protein, and lectins from frog eggs. The relationship between amino acid sequences and possible pathways of the evolution of this protein superfamily is discussed, as well as properties and primary structures of protein ribonuclease inhibitors.

Amino Acid Sequence↗

PubMed1998

[Effects of advance information given by sensory cues on the duration and precision of a pointing movement in Parkinson's disease].

The aim of the present study was to investigate Parkinsonians' ability to process and use the explicit and implicit advance information available about a motor task they are preparing to perform. For this purpose, the performances of 13 Parkinsonians were compared with those of 11 control subjects in a double stimulus reaction time task. The explicit information was provided by a preparatory auditory signal (S1), and the implicit information was conveyed by the probability that the imperative signal (S2) would be consistent with S1 in a given series of trials. Each subject performed 3 successive RT tasks under the following conditions: an oriented cue condition, a neutral cue condition and a primed condition. The results show that the movement times of the Parkinsonians were longer than those of the control subjects, and that they lengthened with the clinical evolution of the disease. Neither the explicit nor the implicit advance information had any effect on the control subjects' performance variables; nor did they affect the Parkinsonians' movement times or pointing areas. The Parkinsonians' systematic errors increased however in the case of primed responses. The fact that the patients' bradykinesia was associated with fairly accurate pointing performances suggests that in Parkinson's disease, a change of voluntary movement performance strategy may occur, involving greater reliance on visual cues.

Acoustic Stimulation↗

PubMed2001

Evolution of body-wall musculature in the Platyhelminthes (Acoelomorpha, Catenulida, Rhabditophora).

In an effort to understand the phylogeny of the Platyhelminthes, the patterns of body-wall musculature of flatworms were studied using fluorescence microscopy and Alexa-488-labeled phalloidin. Species of the Catenulida have a simple orthogonal gridwork of longitudinal and circular muscles. Members of the Rhabditophora have the same gridwork of musculature, but also have diagonal muscles over their entire body. Although a few species of Acoelomorpha possessed a simple orthogonal grid of musculature, most species typically have distinctly different patterns of dorsal and ventral body-wall musculature that include sets of longitudinal, circular, U-shaped, and several kinds of diagonal muscles. Several distinct patterns of musculature were identified, including 8 patterns in 11 families of acoels. These patterns have proven to be useful in clarifying the phylogeny of the Acoelomorpha, particularly with regard to the higher acoels. Patterns of musculature as well as other morphological characters are used here for revisions of acoel systematics, including the return of Eumecynostomum sanguineum (Mecynostomidae) to the genus Aphanostoma (Convolutidae), the revision of the family Childiidae, and the formation of a new family, Actinoposthiidae.

Animals↗

PubMed2006

Evolution of spin-wave excitations in ferromagnetic metallic manganites.

Neutron scattering results are presented for spin-wave excitations of three ferromagnetic metallic A1-xA'xMnO3 manganites (where A and A' are rare- and alkaline-earth-metal ions), which when combined with previous work elucidate the systematics of the interactions as a function of carrier concentration x, on-site disorder, and strength of the lattice distortion. The long-wavelength spin dynamics show only a very weak dependence across the series. The ratio of fourth to first neighbor exchange (J4/J1) that controls the zone boundary magnon softening changes systematically with x, but does not depend on the other parameters. None of the prevailing models can account for these behaviors.

Journal Article↗

PubMed1987

Antitropical distribution and evolution in the Indo-West Pacific Ocean.

Antitropical distributions of continental shelf, Indo-West Pacific species are probably not due to transgression of the tropics during the glacial periods, isothermic submergence, island integration, rising Neogene temperatures, or the Mesozoic dispersal of fragments from a Pacific continental mass. Characteristics of common antitropical patterns, plus information from systematic works on a variety on a variety of animal and plant groups, indicate that the long discarded "relict theory" of Theel (1885) appears to best fit the evidence, for it provides a mechanism whereby antitropical distribution may be brought about. The relict theory is compatible with the concept that the East Indies part of the Indo-West Pacific has been functioning as a center of evolutionary origin. It suggests that antitropical and associated disjunct patterns are produced as an older species, that has spread out to occupy a broad range, loses ground and gradually becomes supplanted by a younger species that had subsequently evolved in the East Indies. As this process goes on, the older species becomes restricted to a few isolated localities on the fringe of its original range. These isolates are often found to the north and south of the equatorial region but may include relict populations at the western edge of the Indian Ocean.

Animals↗

PubMed2006

An RNA-centered view of eukaryotic cells.

Emerging evidence suggests that the introns and intergenic sequences of the genomes of higher eukaryotes (the "junk" DNA) codes for a vast, RNA-based, genetic regulatory network. It is believed that this network is responsible for the variety and complexity of terrestrial life. We conjecture that this regulatory network is more properly viewed as an RNA "community", composed of a rich and largely unexplored biochemical web of RNA interactions. Viewed as an RNA-community, we hypothesize that the RNA regulatory network of higher eukaryotes can re-wire itself, and employ various and evolvable mutational strategies in response to external pressures. Thus, we argue that much evolutionary change is due to intracellular, RNA-mediated learning processes. Successful strategies and pathways are then recorded (hard-wired) into the DNA genome via reverse transcriptase. We present evidence, which is consistent with this viewpoint, and make specific theorems, which could be used to test the utility of our framework. If essentially correct, the RNA-community view of eukaryotic cells could reconcile measured point mutation and gene duplication rates with actual rates of evolutionary change. Futhermore, the RNA-community view of eukaryotic cells suggests that agent-based modeling techniques, used in mathematical economics, game theory, and neuroscience, will likely be as useful in understanding the functioning of eukaryotic cells as the pathway-based approaches of systems biology. We conclude this paper by arguing that a sufficient amount of biological knowledge has been accumulated to initiate a systematic program of experimental and computational studies of the origins and macroevolution of terrestrial life.

Animals↗

PubMed2005

Molecular phylogeny of the benthic shallow-water octopuses (Cephalopoda: Octopodinae).

Octopus has been regarded as a "catch all" genus, yet its monophyly is questionable and has been untested. We inferred a broad-scale phylogeny of the benthic shallow-water octopuses (subfamily Octopodinae) using amino acid sequences of two mitochondrial DNA genes: Cytochrome oxidase subunit III and Cytochrome b apoenzyme, and the nuclear DNA gene Elongation Factor-1alpha. Sequence data were obtained from 26 Octopus species and from four related genera. Maximum likelihood and Bayesian approaches were implemented to estimate the phylogeny, and non-parametric bootstrapping was used to verify confidence for Bayesian topologies. Phylogenetic relationships between closely related species were generally well resolved, and groups delineated, but the genes did not resolve deep divergences well. The phylogenies indicated strongly that Octopus is not monophyletic, but several monophyletic groups were identified within the genus. It is therefore clear that octopodid systematics requires major revision.

Amino Acid Sequence↗

PubMed2003

PCR amplification and sequencing of ITS1 rDNA of Culicoides arakawae.

The first internal transcribed spacer (ITS1) of nuclear ribosomal DNA from Culicoides arakawae was amplified by PCR, cloned and sequenced. The wDNAsis software was used to analyze the ITS1 sequences of C. arakawae and other nine species of Culicoides, which were obtained from GenBank and EMBL databases. For all species, the lengths of the ITS1 were 316-469 bp, and the G+C contents were 26.79-34.53%. Based on the lengths of the ITS1 sequences, the 10 Culicoides species could be divided into two groups. The first group consisted of C. arakawae, C. albicans, C. cubitalis, C. pulicaris and C. punctatus, and the second group comprised C. impunctatus, C. nubeculosus, C. variipennis, C. grisescens and C. imicola. The lengths for the first group were 316-347 bp and the second group were 457-469 bp. C. arakawae belonged to the first group by its ITS1 sequence length. Sequence analysis revealed that C. arakawae was genetically more similar to the first group than it was to the second group, consistent with results based on sequence length. The alignment of ITS1 (the alignment length was 500 bp including the gaps) sequences showed that there was a highly conserved region, which was between 288 and 388 bp, except for a few insertions and substitutions. These findings have important implications for the molecular identification of C. arakawae, for studying its molecular genetics and epidemiology, and for studying the molecular systematics of Culicoides.

Animals↗

PubMed2002

Multilocus isozyme systems in African lungfish, Protopterus annectens: distribution, differential expression and variation in dipnoans.

Distribution of ADH, ALP, FBALD, GAPDH, G3PDH, G6PDH, GPI, LDH, MDH, PGM, and SOD was identified in retina, heart, muscle, liver, kidney, gills, brain, gut, lung and ovary of the African lungfish. Data are compared with patterns previously described in dipnoans and other vertebrates. The number of loci expressed for all enzymes was found to be similar to those of diploid Actinopterygii. Differences in the number of loci expressed in Amphibia were found for ALP, sG3PDH, GPI, LDH, MDH and SOD. Differences in tissue distribution were noted in ALP due to the absence of an intestinal-specific form typical of teleostean fish, amphibians, reptiles and birds, and in GPI and MDH, due to the tissue expression, as in primitive fish. There were also differences in LDH, where a third locus (LDH-C*) was expressed in the gills of Protopterus annectens and not in the retina or liver tissues, as in teleosts. LDH-A4 was most common in all the tissues. Major differences were noted in the tissue patterns of protein expression in the three dipnoans compared. As expected, the least divergence was found between the two species belonging to the same family (Lepidosirenidae). The highest index of divergence was observed between Neoceratodus forsteri and Lepidosiren paradoxa, belonging to the families Ceratontidae and Lepidosirenidae, respectively. The divergence is revealed by changes at the enzyme and morphological levels. These results suggest that P. annectens occupies an interesting systematic position, its biochemical characteristics distinguishing it from N. forsteri, L. paradoxa, the advanced fish and amphibians.

Animals↗

PubMed2003

Combined support for wholesale taxic atavism in gavialine crocodylians.

Morphological and molecular data sets favor robustly supported, contradictory interpretations of crocodylian phylogeny. A longstanding perception in the field of systematics is that such significantly conflicting data sets should be analyzed separately. Here we utilize a combined approach, simultaneous analyses of all relevant character data, to summarize common support and to reconcile discrepancies among data sets. By conjoining rather than separating incongruent classes of data, secondary phylogenetic signals emerge from both molecular and morphological character sets and provide solid evidence for a unified hypothesis of crocodylian phylogeny. Simultaneous analyses of four gene sequences and paleontological data suggest that putative adaptive convergences in the jaws of gavialines (gavials) and tomistomines (false gavials) offer character support for a grouping of these taxa, making Gavialinae an atavistic taxon. Simple new methods for measuring the influence of extinct taxa on topological support indicate that in this vertebrate order fossils generally stabilize relationships and accentuate hidden phylogenetic signals. Remaining inconsistencies in minimum length trees, including concentrated hierarchical patterns of homoplasy and extensive gaps in the fossil record, indicate where future work in crocodylian systematics should be directed.

Adaptation, Biological↗

PubMed1983

Species concept and taxonomic principles.

Based on the species concept of changing versus unchanging, the present work deals with the following two problems: First, why would the taxonomic system reflect evolutionary history? Second, how is this effected? Species are changing in the sense that each species has its own characteristics and there is no complete identity between any two species. On the other hand, species are unchanging and each one conserves a set of ancestral characters which allocates its taxonomic position, and this is the reason why the taxonomic system reflects evolutionary history. The taxonomic system is constructed to reflect evolutionary history mainly through the process of character analysis. Combining the viewpoints of cladistics and evolutionary systematics, the writer proposes six rules for character analysis which will provide the basis for analyzing evolutionary history.

Animals↗

PubMed2004

On the central role of studies on the kidney in the recognition, conceptual evolution, and understanding of hypertension.

Elevated arterial pressure had long been surmised from the strength of the pulse. Its association with contracted kidneys and hypertrophied hearts was described by Richard Bright (1789-1858). Microscopic observations of the narrowed and obliterated vasculature initially observed in the kidneys of Bright's disease, and subsequently throughout the body, launched clinical research into hypertension. The description of these findings in the absence of symptoms of kidney disease led to the recognition of primary hypertension. Ultimately, the systematic recording of the blood pressure with a pneumatic cuff and mercury manometer established the significance of hypertension as a distinct disease entity. Subsequent experimental studies established the central role of the kidney in hypertension through the renin-angiotensin system and extracellular volume control. This finding provided the basis for the introduction of diuretics and angiotensin converting enzyme inhibitors, two of the most important and valuable antihypertertensive drugs now available. Thus, the study of kidney disease and function has played a pivotal role in the conceptual evolution of the understanding of hypertension as a disease, the identification of its mechanisms, and the development of clinically useful antihypertensive medications.

Glomerulonephritis↗

PubMed1984

Amino acid sequences of lower vertebrate parvalbumins and their evolution: parvalbumins of boa, turtle, and salamander.

One major parvalbumin each was isolated from the skeletal muscle of two reptiles, a boa snake, Boa constrictor, and a map turtle, Graptemys geographica, while two parvalbumins were isolated from an amphibian, the salamander Amphiuma means. The amino acid sequences of all four parvalbumins were determined from the sequences of their tryptic peptides, which were ordered partially by homology to other parvalbumins. Phylogenetic study of these and 16 other parvalbumin sequences revealed that the turtle parvalbumin belongs to beta lineage, while the salamander sequences belong, one each, to the alpha and beta lineages defined by Goodman and Pechère (1977). Boa parvalbumin, however, while belonging to the beta lineage, clusters within the fish in all reasonably parsimonious trees. The most parsimonious trees show many parallel or back mutations in the evolution of many parvalbumin residues, although the residues responsible for Ca2+ binding are very well conserved. These most parsimonious trees show an actinopterygian rather than a crossoptyrigian origin of the tetrapods in both the alpha and beta groups. One of two electric eel parvalbumins is evolving more than 10 times faster than its paralogous partner, suggesting it may be on its way to becoming a pseudogene. It is concluded that varying rates of amino acid replacement, much homoplasy, considerable gene duplication, plus complicated lineages make the set of parvalbumin sequences unsuitable for systematic study of the origin of the tetrapods and other higher-taxa divergence, although it may be suitable within a genus or family.

Amino Acid Sequence↗