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PubMed1998

[Treatment review in rhinocerebral mucormycosis].

The rhinocerebral mucormycosis is the more common form produced by Rhizopus, a genus of fungi. It's a serious infective disease with high mortality, that needs a precocious medical treatment. Amphotericin B is the choice medical treatment, but liposomal amphotericine B in recent years is a better drug, due to minor renal toxicity and greater tisular diffusion. Even can not to treat all affected areas it's necessary an extensive surgical treatment according to individual characteristics and disease evolution. A 56-year-old man with rhinocerebral mucormycosis, caused by Rhizopus, who was treated with liposomal-amphotericin B and extensive rhino-orbital surgery is presented.

Amphotericin B↗
PubMed1990

Neuroethological approaches to the evolution of neural systems.

Over the past two decades, neuroethologists have been unravelling the neural circuitry underlying some of the specialized capabilities animals use to obtain and process sensory information. Explicitly comparative studies of these systems can now be carried out to ask questions about the processes of evolutionary change in neural systems. In some cases, it can be seen how relatively minor modifications of neural networks may significantly expand the efficacy of sensory processing. Other comparative studies might ask whether expanding the number of steps involved in neural computation, or the area devoted to the representation of a particular sub-modality, constrains neural architecture in predictable ways.

Animals↗
PubMed1992

Compositional bimodality and evolution of retroviral genomes.

The compositional distributions of genomes, genes (and their third codon positions) and long terminal repeats from retroviruses of warm-blooded vertebrates are characterized by a striking bimodality which is accompanied by a remarkable compositional homogeneity within each retroviral genome. A first, major class of retroviral genomes is GC-rich, whereas a second, minor class is GC-poor. Representative expressed viral genomes from the two classes integrate in GC-rich and GC-poor isochores, respectively, of host genomes. The first class comprises all oncoviruses (except B-types and some D-types), the second, lentiviruses, spumaviruses, as well as B-type and some D-type oncoviruses (e.g., mouse mammary tumor virus and simian retroviruses type D, respectively). The compositional bimodal distribution of retroviral genomes and the accompanying compositional homogeneity within each retroviral genome appear to be the result of the compositional evolution of retroviral genomes in their integrated form.

Animals↗
PubMed1996

[Pulmonary arterial hypertension and heart transplantation: hemodynamic evolution and survival].

BACKGROUND: Patients with chronic heart failure and pulmonary arterial hypertension are at risk of developing fatal right graft failure after transplantation, and there is no agreement about the limit of pulmonary vascular resistance for such risk. PURPOSE: To study what the impact is on the survival of a degree of pulmonary hypertension not considered to be an exclusion for orthotopic heart transplantation and to analyze the hemodynamic profile in the minor circuit after surgery. PATIENTS AND METHODS: We studied a group of 69 patients consecutively transplanted and with followup of at least one year. Patients were classified in two groups depending on the hemodynamic factors previous to transplant: group A (without pulmonary hypertension, 22 patients) and group B (with pulmonary hypertension, 47 patients). After heart transplantation we analyzed the causes of mortality and the evolution hemodynamic profile in both groups. RESULTS: In the group of patients with pulmonary hypertension there was an increase in perioperative mortality due to graft failure (p < 0.05), although at the end of the first year, the survival rate was similar in both groups. After heart transplantation, the level of pulmonary pressures dropped in the same group, but at the end of the first year, a 17% of the patients maintains some criteria of pulmonary hypertension. CONCLUSIONS: Our results confirm that degrees of pulmonary hypertension classically not considered as an exclusion for orthotopic heart transplantation were associated with an increase mortality by graft failure. The majority of survivors after heart transplantation normalize pulmonary pressures at one year of transplantation.

Adult↗
PubMed1992

On the nature of global classification.

Molecular sequencing technology has brought biology into the era of global (universal) classification. Methodologically and philosophically, global classification differs significantly from traditional, local classification. The need for uniformity requires that higher level taxa be defined on the molecular level in terms of universally homologous functions. A global classification should reflect both principal dimensions of the evolutionary process: genealogical relationship and quality and extent of divergence within a group. The ultimate purpose of a global classification is not simply information storage and retrieval; such a system should also function as an heuristic representation of the evolutionary paradigm that exerts a directing influence on the course of biology. The global system envisioned allows paraphyletic taxa. To retain maximal phylogenetic information in these cases, minor notational amendments in existing taxonomic conventions should be adopted.

Biological Evolution↗
PubMed1981

[Sublingual structures of primates. II. Hominoidea, review, summary and literature].

1. In Homo and the great apes (Pongidae) there occurs, besides the plica sublingualis a plica fimbriata at the ventral surface of the tongue. This duplicature of the mucosa does not occur in the Hylobytidae and in the other primates. 2. Some taste buds could be found in the epithelium of the plica sublingualis of the Pongidae. 3. There are many taste buds in the epithelium of the plica fimbriata of the Pongidae. On this sublingual structure there were counted 1776 taste buds in Pongo, 592 in Gorilla and 280 in Pan. A few taste buds could also be found on the plica fimbriata of a human newborn. 4. A glandula apicis linguae occurs in Homo, Pan, Gorilla and Pongo. 5. The fresh saliva of the glandula apicis linguae and the saliva on the floor of the mouth can be tested by the taste buds in the epithelium of the plica fimbriata, of papillae lenticulares and of areae gustatoriae at the ventral surface of the tongue. 6. It might be the function of the sublingual taste buds to taste the fresh saliva as a gradient for the central nervous comparison with the taste of the saliva on the dorsal surface of the tongue. 7. Because of the complete absence of a sublingua in the Platyrrhini and in the Cercopithecinae it is unlikely that the plica fimbriata of Homo and the great apes can be interpreted as a homalogon of the sublingua in the prosimians. 8. Because of the absence of a sublingua in other ordines of the Mammalia (Insectivora, Carnivora, Rodentia, Chiroptera, Ungulata) it is unlikely as well that the sublingua in the prosimians can be interpreted as a homologon of the tongues of the lower vertebrates. The sublingual structures occuring in the Marsupialia have to be investigated. 9. Because of these reasons the new development of the sublingua in the prosimians and the plica fimbriata in the Hominoidea, in complete independence from one another, seems to be a better explanation of the 2 structures and less contradictionary to anatomical and phylogenetic arguments. The different function of both structures in the recent primates gives a hint for the possible reason for their development during the process of evolution.

Animals↗
PubMed2006

The evolution of hyperactivity, impulsivity and cognitive diversity.

The evolutionary status of attention deficit/hyperactivity disorder (ADHD) is central to assessments of whether modern society has created it, either physically or socially; and is potentially useful in understanding its neurobiological basis and treatment. The high prevalence of ADHD (5-10%) and its association with the seven-repeat allele of DRD4, which is positively selected in evolution, raise the possibility that ADHD increases the reproductive fitness of the individual, and/or the group. However, previous suggestions of evolutionary roles for ADHD have not accounted for its confinement to a substantial minority. Because one of the key features of ADHD is its diversity, and many benefits of population diversity are well recognized (as in immunity), we study the impact of groups' behavioural diversity on their fitness. Diversity occurs along many dimensions, and for simplicity we choose unpredictability (or variability), excess of which is a well-established characteristic of ADHD.Simulations of the Changing Food group task show that unpredictable behaviour by a minority optimizes results for the group. Characteristics of such group exploration tasks are risk-taking, in which costs are borne mainly by the individual; and information-sharing, in which benefits accrue to the entire group. Hence, this work is closely linked to previous studies of evolved altruism.We conclude that even individually impairing combinations of genes, such as ADHD, can carry specific benefits for society, which can be selected for at that level, rather than being merely genetic coincidences with effects confined to the individual. The social benefits conferred by diversity occur both inside and outside the 'normal' range, and these may be distinct. This view has the additional merit of offering explanations for the prevalence, sex and age distribution, severity distribution and heterogeneity of ADHD.

Adaptation, Biological↗
PubMed2000

Evolution of different subfamilies of mariner elements within the medfly genome inferred from abundance and chromosomal distribution.

The abundance and distribution pattern of eight mariner elements from three different subfamilies in the genome of the medfly Ceratitis capitata were determined. The copy numbers, as determined by slot-blot analysis, were very different for these elements. Their abundance did not change significantly within the native, the ancient or the newly derived populations, indicating that the rapid colonization process of the medfly had not affected the copy number of mariner elements. The distribution of the mariner elements was analyzed using fluorescent in situ hybridization (FISH) with charge-coupled device (CCD) camera analysis. The pattern of distribution in euchromatin and heterochromatin varied greatly and was distinctive and specific for each element. The implications of these findings are discussed and it is concluded that they generally support the hypothesis of a transposition/selection model in which the abundance and distribution patterns of these elements are regulated primarily by selection against deleterious effects due to meiotic ectopic recombination, while genetic drift would have played a minor role.

Animals↗
PubMed2001

Predicting natural attenuation of xylene in groundwater using a numerical model.

The aquifer beneath an abandoned refinery in the Lower Rhine area, Germany, was contaminated with a number of different mineral oil products. Groundwater sampling in the area around the former xylene plant revealed that a xylene plume had developed in the underlying groundwater, and moreover, that there is strong evidence for in situ microbial xylene degradation with oxygen, nitrate, sulfate and ferric iron as electron acceptors. In order to prevent further xylene spreading, three pumping wells extracting contaminated water were installed downgradient of the spill zone. The numerical reactive transport code Transport Biochemisty Chemistry (TBC) was applied to this situation to quantify the relation of microbial degradation to xylene removal by the pumping wells. It could be shown that the unamended in situ degradation was an appreciable xylene removal process that contributed to about one-third to the total xylene removal (degradation plus extraction). A further objective of the model application was to predict xylene spreading under regional flow conditions, i.e. without operation of the three pumping wells, to consider the possible effects of natural xylene attenuation. To accomplish this, the model calibrated for the situation with operating wells was transferred to the hydraulic situation of regional flow while retaining the parameters of the biochemical model. It turned out that the xylene plume that is expected to develop downgradient of the source area will be limited to an extension of not more than 1000 m. An interesting feature of the simulations results was that xylene degradation under iron-reducing conditions, which was of minor importance for the situation with operating pumping wells, becomes the dominant degradation mechanism under regional flow conditions. Moreover, iron reduction will be the key process in controlling plume evolution. The model application illustrates that multi-species reactive transport models are needed to adequately transfer reactive processes from one hydraulic situation to another, while single species models are not suited for this predictive task.

Forecasting↗
PubMed1998

The absence of phloem loading in willow leaves.

Willow (Salix babylonica L.) is representative of a large group of plants that have extensive plasmodesmatal connections between minor vein phloem and adjoining cells. Because plasmodesmata provide a diffusion pathway for small molecules, it is unclear how sucrose could be loaded from the mesophyll into the phloem against a concentration gradient. In the studies reported here, the minor vein phloem of willow leaves plasmolyzed in approximately the same concentration of osmoticum as the mesophyll. Sucrose concentrations in mesophyll cells were greater than those reported in the literature for aphid stylet exudate from willow stems. Calculated turgor pressures in the mesophyll and minor vein phloem were greater than turgor reported in the literature for sieve elements in the stems of willow. Images of minor veins were not obtained in autoradiographs when attached leaves, or leaf pieces, were provided with 14CO2 or [14C]sucrose. Therefore, no evidence could be found for accumulation of sucrose against a concentration gradient in the minor vein phloem of willow. In these leaves, the mesophyll apparently acts as the "source" for long distance transport of sugar. The mechanism of translocation in willow, and the evolution of phloem loading, are discussed.

Journal Article↗
PubMed2003

Estimated frequency of nonrecessive Bt resistance genes in bollworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae) in eastern North Carolina.

In summer 2000, adult female bollworm moths, Helicoverpa zea (Boddie), were collected from light-traps at four locations near the Tidewater Research Station, Plymouth, NC. Female moths were allowed to lay eggs, and at hatch, 72 larvae from each female were screened for growth rate on normal artificial diet and on diets containing 5.0 microg of either Cry1Ac or Cry2Aa Bt toxin per milliliter of diet. The growth rate bioassays were performed to isolate nonrecessive Bt resistance genes present in field populations of bollworm. We found one individual out of 583 screened that appeared to carry a major gene for resistance to Cry1Ac. Assuming four alleles per individual, the gene frequency is 1/2332 or 0.0003. Other females appeared to have minor genes for Cry1Ac resistance or major genes with lower levels of dominance. We also found one individual out of 646 screened that appeared to carry a major gene for resistance to Cry2Aa. The gene frequency for Cry2Aa resistance was estimated at 1/2584 or 0.00039. Again, other females seemed to carry additional minor resistance genes. Along with other results that indicate partially dominant inheritance of Cry1Ac resistance in bollworm, these allele frequency estimates are important for determining the rate of resistance evolution in H. zea to specific Bt toxins.

Animals↗
PubMedDate not supplied

A study on the safety, efficacy, and efficiency of sulodexide compared with acenocoumarol in secondary prophylaxis in patients with deep venous thrombosis.

This study was carried out to study the safety and efficacy of a fixed dosage of sulodexide compared to adjusted dosages (INR) of acenocoumarol as secondary prophylaxis in patients with deep vein thrombosis (DVT) in lower limbs. An economic evaluation based on the criteria of use in normal clinical practice was also performed. One hundred and fifty patients of both sexes were included, all over 18 years of age and diagnosed with proximal DVT of the lower limbs by color echo-Doppler, and with clinical evolution of less than 1 month. The patients were initially treated with low-molecular-weight heparin (LMWH) and urokinase in accordance with the established protocol. They were then randomized to continue treatment with acenocoumarol and INR adjustments every 30 days, or with sulodexide. Treatment was extended for 3 months with monthly follow-up visits and a final visit at 3 months posttreatment. No differences between the groups were detected concerning demographic or basal characteristics in clinical evolution or adverse reactions. In the group treated with sulodexide, no major/minor hemorrhagic complications were detected. On the other hand, in the acenocoumarol group, 1 major hemorrhage and 9 minor hemorrhages were produced (13.3%), reaching statistical difference in relation to the sulodexide group (p = 0.014; CI from 95% of 4.7% to 19.4%). Regarding the economic impact, treatment costs with sulodexide are much less than those with acenocoumarol, the data confirmed by the sensitivity analyses performed. The results prove the efficacy, safety, and efficiency of sulodexide as a secondary prophylaxis in thromboembolic disease, avoiding hemorrhagic risks and the monitoring of patients, and providing significant savings to the health system.

Acenocoumarol↗
PubMedDate not supplied

[Supra trochlear femoral erosions. Their relations with gonarthrosis and chondrocalcinosis (author's transl)].

Studying one hundred cases of simple gonarthrosis we found only one supra trochlear femoral erosion (STFE). Such a lesion was discovered in 14 cases among 150 chondrocalcinosis with arthrosic lesions. The cases involving STFE trend to a commun marked chondro-osteolytic evolution. The caracteristic patella sizes show clearly that STFE is not in relation with en anomaly of patella (patella alta...). The upper osteophyte of the patella presents only a minor importance in the formation of STFE. This STFE formation begins probably with a progressive chondro-osteolysis of patella and trochlea. Then, appears a progressive nipping between the upper point of patella and the supra trochlear femoral bone.

Aged↗
PubMed2001

Evolution of 17beta-HSD type 4, a multifunctional protein of beta-oxidation.

17beta-Hydroxysteroid dehydrogenase type 4 (17beta-HSD4) is the most unusual among human 17beta-HSDs. It is characterized by a multidomain structure, in which the dehydrogenase domain is fused to a hydratase and a lipid transfer domain. 17beta-HSD4 not only inactivates estradiol by conversion to estrone but its three protein domains also participate in successive steps of peroxisomal beta-oxidation of long- and branched-chain fatty acids. We have compared the genomic structure of human 17beta-HSD4 and several homologous genes from lower animals and fungi. Our data suggest an evolutionary scenario for the three protein domains and indicate a highly dynamic history of the enzyme but also a very high conservation of multifunctionality. This suggests that the main function of human 17beta-HSD4 is still its involvement in fatty-acid metabolism, while steroid conversion is only a secondary and possibly minor activity in vivo.

17-Hydroxysteroid Dehydrogenases↗
PubMed1993

The phylogeny and evolution of the first component of complement, C1.

Extensive study of the phylogeny and evolution of the complement system has always been hampered by the difficulties involved in functional assays. These tests rely on the compatibility of the components from different species. Whereas all mammalian species appear to have almost identical classical, alternate and lytic pathways, non-mammalian vertebrates show minor differences. The source of the immunoglobulin molecule used to demonstrate classical pathway activation has also been shown to be crucial. The use of antibodies directed against complement components has been beneficial in the study of relationships, but cross-reactivity with non-complement proteins limited their use. The isolation and purification of complement components and the biochemical characterisation including amino acid analysis and peptide sequencing resulted in an enormous increase in our knowledge of the evolution of the complement system. Amino acid sequence analysis together with gene cloning of all human complement components finally revealed a number of sofar unknown features concerning the domain structure of the components and the relation of certain motifs and repeats to other proteins. The use of cDNA probes in Southern blot analysis of chromosomal DNA from various species enabled an extension of our scope of the phylogeny of complement. In this article we summarized the data on the phylogeny and evolution of the first component of complement and the associated molecules. We provide evidence for the conservation of the classical pathway and C1q in particular which appears to predate the divergence of the cartilaginous fish from the higher vertebrates. The possibility that the classical pathway could predate the alternate pathway is discussed.

Amino Acid Sequence↗
PubMed1998

Microsatellite evolution: testing the ascertainment bias hypothesis.

Previous studies suggest the median allele length of microsatellites is longest in the species from which the markers were derived, suggesting that an ascertainment bias was operating. We have examined whether the size distribution of microsatellite alleles between sheep and cattle is source dependent using a set of 472 microsatellites that can be amplified in both species. For those markers that were polymorphic in both species we report a significantly greater number of markers (P < 0.001) with longer median allele sizes in sheep, regardless of microsatellite origin. This finding suggests that any ascertainment bias operating during microsatellite selection is only a minor contributor to the variation observed.

Animals↗
PubMed2005

Foot-and-mouth disease virus evolution: exploring pathways towards virus extinction.

Foot-and-mouth disease virus (FMDV) is genetically and phenotypically variable. As a typical RNA virus, FMDV follows a quasispecies dynamics, with the many biological implications of such a dynamics. Mutant spectra provide a reservoir of FMDV variants, and minority subpopulations may become dominant in response to environmental demands or as a result of statistical fluctuations in population size. Accumulation of mutations in the FMDV genome occurs upon subjecting viral populations to repeated bottleneck events and upon viral replication in the presence of mutagenic base or nucleoside analogs. During serial bottleneck passages, FMDV survive during extended rounds of replication maintaining low average relative fitness, despite linear accumulation of mutations in the consensus genomic sequence. The critical event is the occurrence of a low frequency of compensatory mutations. In contrast, upon replication in the presence of mutagens, the complexity of mutant spectra increases, apparently no compensatory mutations can express their fitness-enhancing potential, and the virus can cross an error threshold for maintenance of genetic information, resulting in virus extinction. Low relative fitness and low viral load favor FMDV extinction in cell culture. The comparison of the molecular basis of resistance to extinction upon bottleneck passage and extinction by enhanced mutagenesis is providing new insights in the understanding of quasispecies dynamics. Such a comparison is contributing to the development of new antiviral strategies based on the transition of viral replication into error catastrophe.

Biological Evolution↗