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PubMed2002

Cytotoxic mycosis fungoides evolving from pityriasis lichenoides chronica in a seventeen-year-old girl. Report of a case.

Pityriasis lichenoides chronica and its acute form, pityriasis lichenoides et varioliformis acuta, are skin diseases of unknown origin, that probably represent a hypersensitivity reaction to an infective agent. Pityriasis lichenoides is often a benign disorder but, because of the presence of a clonal T cell population detected both in the chronic and acute forms, some authors have suggested that it may belong to the group of primary cutaneous T cell lymphomas. Although various studies have clearly documented no significant association between pityriasis lichenoides and malignant lymphomas, cases of long-standing pityriasis lichenoides evolving into mycosis fungoides have been described. Herein we report the case of a girl suffering from pityriasis lichenoides since the age of 11 years, subsequently developing a CD45RO+, CD8+, TIA-1+ mycosis fungoides.

Adolescent↗

PubMed2004

Keeping sensory cells and evolving neurons to connect them to the brain: molecular conservation and novelties in vertebrate ear development.

The evolution of the mechanosensory cellular module and the molecular details that regulate its development has included morphological modifications of these cells as well as the formation of larger assemblies of mechanosensory cell aggregates among metazoans. This has resulted in a wide diversity of mechanosensory organs. The wide morphological diversity of organs, including the associated morphological modifications of the mechanosensory cells, suggests parallel evolution of these modules and their associated organs. This morphological diversity is in stark contrast to the molecular conservation of developmental modules across phyla. These molecular data suggest that the evolution of mechanosensory transduction might have preceded that of distinct cellular differentiation. However, once a molecular network governing development of specialized cells involved in mechanosensory transduction evolved, that molecular network was preserved across phyla. Present data suggest that at least the common ancestor of triploblastic organisms, perhaps even the common diploblastic ancestor of bilaterian metazoans, had molecular and cellular specializations for mechanosensation. It is argued that the evolution of multicellular organs dedicated to specific aspects of mechanosensation, such as gravity and sound perception, are evolutionary transformations that build on this conserved molecular network for cellular specialization, but reflect distinct morphological solutions. We propose that the sensory neurons, connecting the craniate ear with the brain, are a derived feature of craniates, and possibly chordates, that came about through diversification of the lineage forming mechanosensory cells during development. This evolutionarily late event suggests a heterochronic shift, so that sensory neurons develop in mammals prior to mechanosensory hair cells. However, sensory neuron development is connected to hair cell development, likely in a clonal relationship. The theme of cellular conservation is reiterated in two examples of chordate otic diversification: the evolution of the horizontal canal system and the evolution of the basilar papilla/cochlea. It is suggested that here again, cellular multiplication and formation of a special epithelium predates the functional transformation to an 'organ' system for horizontal angular acceleration and sound pressure reception, respectively. Overall, evolution of the vertebrate ear needs to be understood as an interplay between and utilization of two gene networks or modules. One is at the level of the molecularly and developmentally conserved mechanosensory cellular module. The other is an increased complexity in the morphology of both adult mechanosensory cells and organs by the addition of end-stage and novel features and associated gene networks to detect specific aspects of mechanosensory stimuli.

Animals↗

PubMed2006

Evolving paradigms for neuroprotection: molecular identification of ischemic penumbra.

Ischemic penumbra defines the existence of tissue at risk of infarction and which is, hence, potentially salvageable and the target for current stroke reperfusion and neuroprotective therapies. Penumbral tissue evolves toward irreversibly damaged tissue at different rates in individual stroke patients yielding different therapeutic windows depending on the individual duration of risk of infarction of this tissue. An accurate identification of the penumbra is then necessary in order to individualize the window of opportunity for therapeutic interventions. Imaging techniques, although helpful, may not give the most accurate information as to the existence of penumbra given that the threshold for identification of penumbra varies depending on the technique used. A better identification of the true penumbral tissue might be based on the cascade of molecular events that are responsible for the evolution of the penumbra toward infarcted tissue. Multiple penumbras can be defined in molecular terms taking into account which vessel is occluded, the time of evolution of the ischemia, the degree of the ischemia, and the sensitivity to ischemia of the different cells. Future studies are necessary to clarify whether the enhancement of cytoprotective mechanisms, and/or the block of cytotoxic mechanisms confirming the existence of penumbra at different times of ischemic evolution, are effective neuroprotective strategies.

Animals↗

PubMed1995

Chromosomal painting shows that "marked chromosomes" in lesser apes and Old World monkeys are not homologous and evolved by convergence.

Cytogeneticists have long held that the single pair of metacentric, NOR-bearing "marked chromosomes" in lesser apes (Hylobatidae) and Old World monkeys (Cercopithecidae) are homologous. Hylobatids have sometimes been excluded from Hominoidea (great apes and humans) and phylogenetically allied with the lower primates, primarily on the basis of this shared "trait." However, in situ hybridization of human chromosome-specific DNA probes to chromosomes of Hylobates lar, H. syndactylus, H. concolor, Cercopithecus aethiops, Macaca fuscata, Colobus guereza, and Presbytis cristata showed that the so-called "marked chromosomes" in Hylobatidae and Cercopithecidae evolved by convergence. Therefore, "marked chromosomes" cannot be used to exclude gibbons from Hominoidea or to link Hylobatidae with monkeys. Chromosomal painting is a powerful tool to resolve problems of chromosomal homology and helps eliminate phylogenetic errors due to confusing convergence with homology. Chromosomal painting improves the confidence in using cytogenetic data for evolutionary studies, especially in phylogeny and taxonomy.

Animals↗

PubMed1988

Characterization of transformed cell lines evolving from a normal C3H line.

The development of transformed cell lines evolving from an embryo fibroblastic C3H primary culture was followed before and after the ageing crisis using different techniques. By flow cytometry, alteration of subpopulations having different DNA content and altered metabolic activity was observed after the crisis, with the trend to assume a near tetraploid DNA index at higher passages. The fibrin clot retractile activity was lost in all cases during the ageing crisis, but the outcome did not present uniform values of growth characteristics or chromosome number and tumorigenicity appeared to be a nonstable property of the transformed cell lines.

Animals↗

PubMed1990

Does the extent of the zone at risk after coronary artery occlusion influence the percentage of the zone that evolves to infarction?

To examine whether the extent of the zone at risk for infarction after coronary artery occlusion influences the percentage of the zone that evolves to necrosis in the absence of intervention, 99mTc-labeled albumin microspheres were injected into the left atrium 1 min after coronary occlusion in 34 dogs. Six hours after occlusion, the left ventricle was cut into 3-mm-thick slices for triphenyltetrazolium chloride staining and autoradiography. The extent of myocardial necrosis and hypoperfused zone was measured by planimetry and expressed as a percentage of the total volume of the left ventricle. The extent of myocardial necrosis and hypoperfused zone varied widely from 8 to 40% and 14 to 43% of the left ventricle, respectively. However, there was a close correlation between infarct size (IS, percent of left ventricle) and the extent of hypoperfused zone (HZ, percent of left ventricle): IS = 0.89x (HZ) - 0.21 (r = 0.909, SEE = 3.02, p less than 0.01). The ratio of infarct size to the extent of hypoperfused zone was 87.9 +/- 2.3%. Dogs with large hypoperfused zones (greater than or equal to 30% of the left ventricle) had a significantly greater ratio of infarct size to the extent of the hypoperfused zone (95.3 +/- 2.4%, n = 11, p less than 0.05) than dogs with small hypoperfused zones (less than 30% of the left ventricle; 84.3 +/- 3.0%, n = 23). Moreover, the ratio was greater than or equal to 90% in all but one dog (91%) with large hypoperfused zones, but in only 10 of 23 dogs (43%) with small hypoperfused zones (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1984

Acquired hemoglobin H disease in a case of refractory anemia with excess of blasts (RAEB) evolving into acute nonlymphoid leukemia.

A new case of refractory anemia with excess of blasts (RAEB) with acquired Hemoglobin H disease (HbH) evolving into acute nonlymphoid leukemia (ANLL) is reported. In this patient, both family and personal history were negative for alpha thalassemia. At time of diagnosis of RAEB, 'golf ball' erythrocytic inclusions, typical of HbH, were found. The cellulose acetate electrophoresis (pH 8.9) revealed a fast moving band, corresponding to HbH. An evolution into ANLL, M1 subtype, 25 months later, has been documented.

Aged↗

PubMed1992

A typology of alcoholism in Taiwan aborigines: a study on evolving process of community cases.

Thirty-one habitual drinkers with a personal, familial, social complication were screened from a Taiwan aborigine community. Each was given an in-depth descriptive semistructured interview. The interview, recorded with audiotape, contained 4 aspects: (1) personal developmental history; (2) family structure and interaction; (3) developmental process and current state of drinking behavior, and (4) attitude toward drinking behavior. Based on the evolving process and current state of drinking behavior, three process patterns of alcoholism were defined: (1) social developmental type (67.7%); (2) deviant behavioral type (9.7%), and (3) special constitutional type (22.6%).

Adult↗

PubMed1999

Constrictive pericarditis in the modern era: evolving clinical spectrum and impact on outcome after pericardiectomy.

BACKGROUND: The clinical spectrum of constrictive pericarditis (CP) has been affected by a change in incidence of etiological factors. We sought to determine the impact of these changes on the outcome of pericardiectomy. METHODS AND RESULTS: The contemporary spectrum of CP in 135 patients (76% male) evaluated at the Mayo Clinic from 1985 to 1995 was compared with that of a historic cohort. Notable trends were an increasing frequency of CP due to cardiac surgery and mediastinal radiation and presentation in older patients (median age, 61 versus 45 years). Perioperative mortality decreased (6% versus 14%, P = 0.011), but late survival was inferior to that of an age- and sex-matched US population (57+/-8% at 10 years). The long-term outcome was predicted independently by 3 variables in stepwise logistic regression analyses: (1) age, (2) NYHA class, and most powerfully, (3) a postradiation cause. Of 90 late survivors in whom functional class could be determined, functional status had improved markedly (2.6+/-0.7 at baseline versus 1.5+/-0.8 at latest follow-up [P<0.0001]), with 83% being free of clinical symptoms. CONCLUSIONS: The evolving profile of CP, with increasingly older patients and those with radiation-induced disease in the past decade, significantly affects postoperative prognosis. Long-term results of pericardiectomy are disappointing for some patient groups, especially those with radiation-induced CP. By contrast, surgery alleviates or improves symptoms in the majority of late survivors.

Adolescent↗

PubMed1983

Sustained improvement in left ventricular function and mortality by intracoronary streptokinase administration during evolving myocardial infarction.

One hundred eighty-eight patients with acute myocardial infarction were studied prospectively from August 1980 to September 1982. One hundred thirty-six of these patients were entered into a intracoronary streptokinase study after informed consent was obtained. The remaining 52 patients, who either met exclusion criteria for the study or refused to participate, served as a control group and were treated as those in the study group except that they did not undergo emergency cardiac catheterization. Left ventricular function was determined in both groups by gated radionuclide ejection fraction (EF) on admission to the hospital, at discharge, and 6 months after discharge. With successful reperfusion up to 18 hr after onset of chest pain, mean left ventricular function in the study group improved (EF 39 +/- 13% on admission and 46 +/- 12% at discharge; p less than .001). Mean EF in control patients and those not achieving reperfusion did not change from admission to discharge. Mean EF at 6 month follow-up was not significantly different than at discharge in the study group or the control group. Total cardiac mortality in the control group was 19% compared with 10% in the study group (p = .06, NS). When patients admitted in pulmonary edema or shock (Killip class III or IV) were excluded from both groups, total cardiac mortality in the study group was significantly lower (4%) compared with in the control group (12.5%, p less than .05. The administration of intracoronary streptokinase during evolving myocardial infarction up to 18 hr after onset of chest pain may result in decreased mortality and sustained improvement in left ventricular function.

Aged↗

PubMed1992

Left atrial contribution to ventricular filling during the course of evolving heart failure.

BACKGROUND: Abnormal left ventricular (LV) filling has been observed in patients with heart failure and is characterized by marked heterogeneity of mitral inflow velocity. In the present study, the contribution of the left atrium to LV filling was examined in eight dogs during the course of evolving heart failure. METHODS AND RESULTS: Heart failure was produced by multiple sequential intracoronary embolizations with microspheres. Pulsed Doppler echocardiography was used to measure mitral inflow velocity at baseline, before embolization, and at 3, 8, 15, 23, and 33 weeks after initiation of microembolization. The early rapid LV filling (Ei) and late left atrial filling (Ai) components were quantitated based on the time-velocity integral of the early and late mitral inflow velocity waveforms, respectively. Ei decreased progressively from 7.6 +/- 1.5 cm at baseline to 4.0 +/- 0.4 cm at 33 weeks (p less than 0.01). In contrast, Ai initially increased from 1.8 +/- 0.9 cm at baseline to 2.7 +/- 0.4 cm at 3 weeks (p less than 0.01) and subsequently decreased gradually to below baseline values reaching 0.8 +/- 0.4 cm at 33 weeks (p less than 0.01). These temporal changes of Ei and Ai were accompanied by a gradual reduction of LV ejection fraction (56 +/- 5% versus 22 +/- 2%) (p less than 0.01) (baseline versus 33 weeks) and by a gradual increase of LV end-diastolic wall stress (24 +/- 7 versus 92 +/- 8 g/cm2) (p less than 0.01), left atrial dimension (2.4 +/- 0.2 cm to 3.3 +/- 0.3 cm) (p less than 0.01), and left atrial fractional shortening (22 +/- 3% versus 15 +/- 2%) (p less than 0.01). CONCLUSIONS: The initial rise in left atrium contribution to LV filling may represent a compensatory response to the diminution of the rapid early component of LV filling. With further progression of LV dysfunction, the left atrium contribution to LV filling gradually decreased. This reduction may be mediated by increased workload imposed on the left atrial myocardium due to increased LV diastolic wall stress, which, over time, may have lead to intrinsic left atrium dysfunction.

Animals↗

PubMed1993

Coronary thrombolysis with recombinant staphylokinase in patients with evolving myocardial infarction.

BACKGROUND: Staphylokinase (STA), a protein with known profibrinolytic properties, is produced by transduced Staphylococcus aureus strains. In experimental animal models, recombinant staphylokinase (STAR) is less immunogenic and more active toward platelet-rich arterial blood clots than streptokinase. METHODS AND RESULTS: In the present study, 10 mg STAR given intravenously over 30 minutes was found to induce angiographically documented coronary artery recanalization within 40 minutes in four of five patients with acute myocardial infarction. Plasma fibrinogen and alpha 2-antiplasmin levels were unaffected, and allergic reactions were not observed. Postinfusion disappearance of STAR antigen followed a biphasic mode with a t1/2 alpha of 6.3 +/- 0.6 minutes (mean +/- SD) and a t1/2 beta of 37 +/- 15 minutes, corresponding to a plasma clearance of 270 +/- 100 mL/min. Neutralizing antibodies against STAR could not be demonstrated at baseline and up to 6 days after infusion, but STAR neutralizing activity, which did not cross-react with streptokinase, was consistently demonstrable in plasma at 14-35 days. CONCLUSIONS: STAR can induce clot-selective coronary thrombolysis in patients with evolving myocardial infarction without concomitant induction of a systemic lytic state. STAR, a small protein that can be easily produced by recombinant DNA technology, may therefore offer promise for thrombolytic therapy in patients with thromboembolic disease.

Aged↗

PubMed2001

All-blood (miniplegia) versus dilute cardioplegia in experimental surgical revascularization of evolving infarction.

BACKGROUND: The advantages of blood cardioplegia include the oxygen-carrying capacity, superior oncotic and buffering properties, and endogenous antioxidants contained in blood. However, the partial dilution of blood in 4:1 (blood:crystalloid) cardioplegic solutions may nullify these advantages and progressively dilute blood during continuous retrograde delivery. This study tested the hypothesis that all-blood (66:1) cardioplegia provides superior myocardial protection compared with dilute (4:1) cardioplegia delivered in a continuous retrograde modality during surgical reperfusion of evolving myocardial infarction. METHODS AND RESULTS: After 60 minutes of left anterior descending coronary artery (LAD) occlusion, anesthetized canines were placed on cardiopulmonary bypass and randomized to either all-blood cardioplegia (AB group) or dilute blood cardioplegia (Dil group). After cross clamping, arrest was induced with 5 minutes of tepid (30 degrees C) antegrade potassium all-blood or dilute blood cardioplegia and maintained with tepid retrograde coronary sinus cardioplegia for a total of 1 hour. The LAD was released after 30 minutes of arrest, simulating revascularization. The cardioplegia hematocrit for the Dil group was lower than that for the AB group (7+/-1% versus 12+/-2%, P<0.05); at the end of bypass, systemic hematocrit was lower in the Dil group than in the Ab group (15+/-1% versus 20+/-1%, P<0.05). Infarct size (triphenyltetrazolium chloride staining) was comparable between the AB and Dil groups (29.6+/-2.9% versus 30.3+/-3.9% of area at risk), and there was no difference in area-at-risk myocardium systolic shortening (by sonomicrometry, -0.3+/-1% versus -0.4+/-1%). Tissue edema after bypass tended to be greater in the Dil group compared with the AB group in the heart (82+/-0% versus 81+/-1%), lung (79+/-1% versus 78+/-1%), liver (75+/-1% versus 74+/-0%), and skeletal muscle (76+/-1% versus 73+/-2%) and was significantly greater in the duodenum (80+/-1% versus 79+/-1%, P<0.05) and kidney (82+/-1% versus 79+/-1%, P<0.05). Postexperimental endothelial function (relaxation of acetylcholine) was impaired in LADs of the AB group versus the Dil group (59+/-6% versus 77+/-5%, P<0.05). CONCLUSIONS: Both all-blood cardioplegia and dilute cardioplegia have disadvantages, but these do not have an impact on the pathogenesis of infarct size or recovery of regional contractile function.

Animals↗

PubMed2001

Evolving control metabolisms for a robot.

This article demonstrates a new method of programming artificial chemistries. It uses the emerging capabilities of the system's dynamics for information-processing purposes. By evolution of metabolisms that act as control programs for a small robot one achieves the adaptation of the internal metabolic pathways as well as the selection of the most relevant available exteroceptors. The underlying artificial chemistry evolves efficient information-processing pathways with most benefit for the desired task, robot navigation. The results show certain relations to such biological systems as motile bacteria.

Metabolism↗

PubMed2001

Evolving collective behavior in an artificial ecology.

Collective behavior refers to coordinated group motion, common to many animals. The dynamics of a group can be seen as a distributed model, each "animal" applying the same rule set. This study investigates the use of evolved sensory controllers to produce schooling behavior. A set of artificial creatures "live" in an artificial world with hazards and food. Each creature has a simple artificial neural network brain that controls movement in different situations. A chromosome encodes the network structure and weights, which may be combined using artificial evolution with another chromosome, if a creature should choose to mate. Prey and predators coevolve without an explicit fitness function for schooling to produce sophisticated, nondeterministic, behavior. The work highlights the role of species' physiology in understanding behavior and the role of the environment in encouraging the development of sensory systems.

Animals↗

PubMed1998

Evolving reaction-diffusion ecosystems with self-assembling structures in thin films.

Recently, new types of coupled isothermal polynucleotide amplification reactions for the investigation of in vitro evolution have been established that are based on the multi-enzyme 3SR reaction. Microstructured thin-film open bioreactors have been constructed in our laboratory to run these reactions spatially resolved in flow experiments. Artificial DNA/RNA chemistries close to the in vitro biochemistry of these systems have been developed, which we have studied in computer simulations in configurable hardware (NGEN). These artificial chemistries are described on the level of individual polynucleotide molecules, each with a defined sequence, and their complexes. The key feature of spatial pattern formation provides a weak stabilization of cooperative catalytic properties of the evolving molecules. Of great interest is the step to include extended self-assembly processes of flexible structures-allowing the additional stabilization of cooperation through semipermeable, flexible, self-organizing membrane boundaries. We show how programmable matter simulations of experimentally relevant molecular in vitro evolution can be extended to include the influence of self-assembling flexible membranes.

Bioreactors↗

PubMed1999

Evolving learnable neutral networks under changing environments with various rates of inheritance of acquired characters: comparison between Darwinian and Lamarckian evolution.

The processes of adaptation in natural organisms consist of two complementary phases: learning, occurring within each individual's lifetime, and evolution, occurring over successive generations of the population. In this article, we study the relationship between learning and evolution in a simple abstract model, where neural networks capable of learning are evolved using genetic algorithms (GAs). Individuals try to maximize their life energy by learning certain rules that distinguish between two groups of materials: food and poison. The connective weights of individuals' neural networks undergo modification, that is, certain characters will be acquired, through their lifetime learning. By setting various rates for the heritability of acquired characters, which is a motive force of Lamarckian evolution, we observe adaptational processes of populations over successive generations. Paying particular attention to behaviors under changing environments, we show the following results. Populations with lower rates of heritability not only show more stable behavior against environmental changes, but also maintain greater adaptability with respect to such changing environments. Consequently, the population with zero heritability, that is, the Darwinian population, attains the highest level of adaptation to dynamic environments.

Algorithms↗

PubMed1999

A new structurally dissolvable self-reproducing loop evolving in a simple cellular automata space.

We constructed a simple evolutionary system, "evoloop," on a deterministic nine-state five-neighbor cellular automata (CA) space by improving the structurally dissolvable self-reproducing loop we had previously contrived [14] after Langton's self-reproducing loop [7]. The principal role of this improvement is to enhance the adaptability (a degree of the variety of situations in which structures in the CA space can operate regularly) of the self-reproductive mechanism of loops. The experiment with evoloop met with the intriguing result that, though no mechanism was explicitly provided to promote evolution, the loops varied through direct interaction of their phenotypes, smaller individuals were naturally selected thanks to their quicker self-reproductive ability, and the whole population gradually evolved toward the smallest ones. This result gives a unique example of evolution of self-replicators where genotypical variation is caused by precedent phenotypical variation. Such interrelation of genotype and phenotype would be one of the important factors driving the evolutionary process of primitive life forms that might have actually occurred in ancient times.

Artificial Intelligence↗