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PubMedDate not supplied

Morphological evaluation of full-thickness idiopathic macular holes by optical coherence tomography.

PURPOSE: To assess the efficacy of optical coherence tomography (OCT) for the morphological evaluation of idiopathic full-thickness macular holes and for detecting any morphological changes with time. METHODS: Serial sagittal tomographs through the macula were taken by OCT in a consecutive series of 34 eyes of 34 patients with diagnosis of idiopathic full-thickness macular hole. The patients were divided into two groups on the basis of "recent" (group 1, 25 patients) or "not-recent" (group 2, 9 patients) onset of symptoms related to the macular hole. Fourteen of the 25 patients in group 1 and all nine in group 2 underwent vitrectomy. The 11 in group 1 who refused surgery were observed by OCT examination with follow-up from 6 to 13 months. RESULTS: In most eyes OCT scans revealed two different anatomical features of macular holes depending on the time of onset of symptoms. Eleven of the 14 "recent-onset" holes that underwent surgery showed "sharp", undermining edges at preoperative OCT; the other three had "rounded" edges. Seven of the nine eyes operated for long-standing full-thickness macular holes had preoperative "rounded" edges, while the edges in the remaining two eyes were "sharp". OCT of eight of the 11 non-operated eyes in group 1 showed a morphological evolution of the macular hole edges from a "sharp" to a "rounded" contour and an increase in the diameter of the hole. CONCLUSIONS: OCT can help in the morphological evaluation of idiopathic full-thickness macular holes and in the detection of morphological changes with time.

Aged↗
PubMed2001

Molecular insights into species phylogeny, biogeography, and morphological stasis in the ancient spider genus Hypochilus (Araneae: Hypochilidae).

The spider genus Hypochilus is currently restricted to cool, moist microhabitats in three widely separated montane regions of North America, providing an opportunity to study both deep (i.e., continental level) and shallow (within montane region) biogeographic history. Members of the genus also retain many plesiomorphic morphological characteristics, inviting the study of comparative rates of morphological evolution. In this paper, Hypochilus phylogeny and associated evolutionary problems are addressed using both new molecular (28S nDNA and CO1 mtDNA) and previously published (K. M. Catley, 1994, Am. Mus. Nov. 3088, 1-27) morphological data. Although the molecular data provide limited resolution of root placement within Hypochilus, most analyses are at least consistent with morphology-supported montane relationships of (Rockies (California, Appalachian)). The monophyly of Hypochilus species distributed in the California mountains is ambiguous, with several analyses indicating that this fauna may be paraphyletic with respect to a monophyletic Appalachian lineage. The montane regions differ in consistent ways in depths of both mitochondrial and nuclear phylogenetic divergence. Molecular clock analyses, in combination with arthropod-based mtDNA rate calibrations, suggest that the regional faunas are of different ages and that speciation in all faunas likely occurred prior to the Pleistocene. Limited intraspecific sampling reveals extraordinarily high levels of mtDNA cytochrome oxidase sequence divergence. These extreme divergences are most consistent with morphological stasis at the species level, despite preliminary evidence that Hypochilus taxa are characterized by fragmented population structures.

Animals↗
PubMed2003

Antiquity and evolution of the MADS-box gene family controlling flower development in plants.

MADS-box genes in plants control various aspects of development and reproductive processes including flower formation. To obtain some insight into the roles of these genes in morphological evolution, we investigated the origin and diversification of floral MADS-box genes by conducting molecular evolutionary genetics analyses. Our results suggest that the most recent common ancestor of today's floral MADS-box genes evolved roughly 650 MYA, much earlier than the Cambrian explosion. They also suggest that the functional classes T (SVP), B (and Bs), C, F (AGL20 or TM3), A, and G (AGL6) of floral MADS-box genes diverged sequentially in this order from the class E gene lineage. The divergence between the class G and E genes apparently occurred around the time of the angiosperm/gymnosperm split. Furthermore, the ancestors of three classes of genes (class T genes, class B/Bs genes, and the common ancestor of the other classes of genes) might have existed at the time of the Cambrian explosion. We also conducted a phylogenetic analysis of MADS-domain sequences from various species of plants and animals and presented a hypothetical scenario of the evolution of MADS-box genes in plants and animals, taking into account paleontological information. Our study supports the idea that there are two main evolutionary lineages (type I and type II) of MADS-box genes in plants and animals.

Animals↗
PubMed1985

[Morphology of adult and sub-adult Wuchereria bancrofti. Differential characteristics among the strains].

The description of the fourth stage larva of W. bancrofti provides an indication of the direction of morphological evolution in the genus showing in particular that W. kalimantani is more highly evolved than W. bancrofti and constitutes a "capture" by Presbytis of the species parasitic in man. No morphological character of adult W. bancrofti distinguishes the geographic origin of the different collections studied. By contrast, the morphological characters of the microfilariae and their biological features are significantly different, but are not inter-correlated. It therefore appears that in the genus Wuchereria, as in the other viviparous filarioids, the phenomenon of speciation is evident first of all in the morphology of the microfilaria, the stage most susceptible to selection pressures.

Aging↗
PubMed1999

A platelet activating factor receptor antagonist prevents the development of chronic arthritis in mice.

OBJECTIVE: To examine the effect of treatment with the platelet activating factor (PAF) receptor antagonist BN 50730 on the clinical and morphological evolution of collagen induced arthritis in mice. METHODS: Mice with collagen induced arthritis were treated with BN 50730 (0.3, 1, 3 mg/kg) or vehicle (0.1% Tween-20 in saline) once a day, from 3 days before the induction of the arthritis to 70 days after. Disease evolution was followed daily by inspection of inflammatory signs and measurement of the knee joint diameter on Days 0, 40, and 70. At the end of the treatment period, the morphological evaluation of the synovial membrane, the immunodetection of fibronectin, and the content of cartilage proteoglycans were studied. RESULTS: On Day 40, mice receiving the highest dose of BN 50730 (3 mg/kg) showed a reduction in the knee joint diameter in comparison with untreated (2.1 +/- 0.2 vs 2.8 +/- 0.4 mm, p < 0.01). On Day 70, animals receiving 1 and 3 mg/kg had a normal knee diameter, while it remained enlarged in the untreated ones. In BN 50730 treated mice (3 mg/kg) we also observed a significant reduction of the inflammation score (0.1 +/- 0.1 vs 2.5 +/- 0.2 in the untreated) and deposition of fibronectin. Depletion of cartilage proteoglycans was also reversed with BN 50730. CONCLUSION: The beneficial effects in this model of joint injury after administration of the PAF antagonist BN 50730 suggest that PAF could be implicated in the pathogenesis of chronic arthritis.

Animals↗
PubMed2002

Gene duplications in the prototypical cephalochordate amphioxus.

The new discipline of Evolutionary Developmental Biology (Evo-Devo) is facing the fascinating paradox of explaining morphological evolution using conserved pieces or genes to build divergent animals. The cephalochordate amphioxus is the closest living relative to the vertebrates, with a simple, chordate body plan, and a genome directly descended from the ancestor prior to the genome-wide duplications that occurred close to the origin of vertebrates. Amphioxus morphology may have remained relatively invariant since the divergence from the vertebrate lineage, but the amphioxus genome has not escaped evolution. We report the isolation of a second Emx gene (AmphiEmxB) arising from an independent duplication in the amphioxus genome. We also argue that a tandem duplication probably occurred in the Posterior part of the Hox cluster in amphioxus, giving rise to AmphiHox14, and discuss the structure of the chordate and vertebrate ancestral clusters. Also, a tandem duplication of Evx in the amphioxus lineage produced a prototypical Evx gene (AmphiEvxA) and a divergent gene (AmphiEvxB), no longer involved in typical Evx functions. These examples of specific gene duplications in amphioxus, and other previously reported duplications summarized here, emphasize the fact that amphioxus is not the ancestor of the vertebrates but 'only' the closest living relative to the ancestor, with a mix of prototypical and amphioxus-specific features in its genome.

Amino Acid Sequence↗
PubMed1997

DNA hybridization evidence for the principal lineages of hummingbirds (Aves:Trochilidae).

The spectacular evolutionary radiation of hummingbirds (Trochilidae) has served as a model system for many biological studies. To begin to provide a historical context for these investigations, we generated a complete matrix of DNA hybridization distances among 26 hummingbirds and an outgroup swift (Chaetura pelagica) to determine the principal hummingbird lineages. FITCH topologies estimated from symmetrized delta TmH-C values and subjected to various validation methods (bootstrapping, weighted jackknifing, branch length significance) indicated a fundamental split between hermit (Eutoxeres aquila, Threnetes ruckeri; Phaethornithinae) and nonhermit (Trochilinae) hummingbirds, and provided strong support for six principal nonhermit clades with the following branching order: (1) a predominantly lowland group comprising caribs (Eulampis holosericeus) and relatives (Androdon aequatorialis and Heliothryx barroti) with violet-ears (Colibri coruscans) and relatives (Doryfera ludovicae); (2) an Andean-associated clade of highly polytypic taxa (Eriocnemis, Heliodoxa, and Coeligena); (3) a second endemic Andean clade (Oreotrochilus chimborazo, Aglaiocercus coelestis, and Lesbia victoriae) paired with thorntails (Popelairia conversii); (4) emeralds and relatives (Chlorostilbon mellisugus, Amazilia tzacatl, Thalurania colombica, Orthorhyncus cristatus and Campylopterus villaviscensio); (5) mountain-gems (Lampornis clemenciae and Eugenes fulgens); and (6) tiny bee-like forms (Archilochus colubris, Myrtis fanny, Acestrura mulsant, and Philodice mitchellii). Corresponding analyses on a matrix of unsymmetrized delta values gave similar support for these relationships except that the branching order of the two Andean clades (2, 3 above) was unresolved. In general, subsidiary relationships were consistent and well supported by both matrices, sometimes revealing surprising associations between forms that differ dramatically in plumage and bill morphology. Our results also reveal some basic aspects of hummingbird ecologic and morphologic evolution. For example, most of the diverse endemic Andean assemblage apparently comprises two genetically divergent clades, whereas the majority of North American hummingbirds belong a single third clade. Genetic distances separating some morphologically distinct genera (Oreotrochilus, Aglaiocercus, Lesbia; Myrtis, Acestrura, Philodice) were no greater than among congeneric (Coeligena) species, indicating that, in hummingbirds, morphological divergence does not necessarily reflect level of genetic divergence.

Americas↗
PubMedDate not supplied

Ontogeny and homoplasy in the papionin monkey face.

Recent molecular research has provided a consistent estimate of phylogeny for the living papionin monkeys (Cercocebus, Lophocebus, Macaca, Mandrillus, Papio, and Theropithecus). This phylogeny differs from morphological phylogenies regarding the relationships of the mangabeys (Cercocebus and Lophocebus) and baboons (Mandrillus, Papio, and Theropithecus). Under the likely assumption that the molecular estimate is correct, the incongruence between the molecular and morphological data sets indicates that the latter include numerous homoplasies. Knowledge of how these homoplasies emerge through development is important for understanding the morphological evolution of the living papionins, and also for reconstructing the phylogenetic relationships and adaptations of their fossil relatives. Accordingly, we have used geometric morphometric techniques and the molecular phylogeny to investigate the ontogeny of a key area of morphological homoplasy in papionins, the face. Two analyses were carried out. The first compared allometric vectors of Cercocebus, Lophocebus, Macaca, Mandrillus, and Papioto determine which of the facial resemblances among the genera are homoplasic and which are plesiomorphic. The second analysis focused on early post-natal facial form in order to establish whether the facial homoplasies exhibited by the adult papionins are to some degree present early in the post-natal period or whether they develop only later in ontogeny. The results of our analyses go some way to resolving the debate over which papionin genera display homoplasic facial similarities. They strongly suggest that the homoplasic facial similarities are exhibited by Mandrillus and Papio and not by Cercocebus and Lophocebus, which share the putative primitive state with Macaca. Our results also indicate that Mandrillus and Papio achieve their homoplasic similarities in facial form not through simple extension of the ancestral allometric trajectory but through a combination of an extension of allometry into larger size ranges and a change in direction of allometry away from the ancestral trajectory. Thus, the face of Mandrillus is not simply a hypermorphic version of the face of its sister taxon, Cercocebus, and the face of Papio is not merely a scaled-up version of the face of its sister taxon, Lophocebus. Lastly, our results show that facial homoplasy is not restricted to adult papionins; it is also manifest in infant and juvenile papionins. This suggests that the homoplasic facial similarities between Mandrillus and Papio are unlikely to be a result of sexual selection.

Animals↗
PubMed1989

Aging of the diaphragm: a CT study.

To determine the normal morphologic evolution of the diaphragm with aging and to correlate age-related changes with other indicators of physical condition--such as skeletal muscle status, obesity, presence of pulmonary emphysema, and presence of esophageal hiatus hernia--a systematic morphometric and morphologic evaluation of computed tomographic studies of 120 patients from the 3d to 8th decades of life was undertaken. Diaphragm muscle thickness did not change significantly with increasing age. Diaphragmatic defects and pseudotumors, nonexistent in the 3d and 4th decades, increased in number and severity to affect 56% of the patients in the 7th and 8th decades. Neither the status of the skeletal muscle nor the presence of obesity correlated with age or with the presence of diaphragmatic defects. Eighty-four percent of the patients with emphysematous changes demonstrated diaphragmatic defects; thus, a strong association with emphysema was observed. If emphysematous patients are excluded, defects were more common in women. The esophageal hiatus width was found to increase with age.

Adult↗
PubMed1996

The adenoma-carcinoma sequence in colorectal neoplasia.

In this article the epidemiologic, pathologic, molecular, and clinical evidence for the adenoma-carcinoma sequence is reviewed. The authors describe the morphologic evolution of the precursor adenomas, from the earliest discernible abnormality of the colon to adenomas with advanced pathologic features, the factors that determine the risk of progression of adenomas to adenocarcinoma, the molecular events that parallel or underlie the morphologic changes, the outcome of clinical interventions that have tested this hypothesis, and the time frame within which this progression is likely to occur.

Adenocarcinoma↗
PubMed1999

Radiation therapy in exudative age-related macular degeneration.

It has been suggested that ionizing radiation at doses relatively safe to the optic nerve and retina exert an inhibitory and occlusive effect on the endothelial proliferation of choroidal neovascularization (CNV) associated with age-related macular degeneration (AMD). The encouraging results of early studies in preservation or improvement of visual acuity and regression of the CNV gave rise to many clinical trials in different centers. Disparate radiation doses, dose fractions, type and rate of radiation administration have been used to determine the efficacy of radiotherapy in AMD. Conflicting treatment responses have been reported by different centers. Some studies provided evidence of beneficial treatment outcome in AMD, and others could not show any efficacy of ionizing radiation in the visual and morphological evolution of the disease. Data from the literature and our experience indicate that radiotherapy can be effective in regressing the leakage of the CNV in AMD. However, despite treatment visual deterioration continues and new CNV lesions develop. The observation of morphological progression in the disease process might be related to an unfavorable effect of radiation on the pathogenesis of AMD.

Choroidal Neovascularization↗
PubMed1993

Genetics, development and plant evolution.

The recent mapping of quantitative trait loci in plants indicates that traits are often controlled by relatively few genes, some of which have large effects. Developmental genetics has shown that plant development is often regulated by transcription factors that activate developmental programs in response to internal or environmental signals. These transcription factors are good candidates for the major genes that govern morphological evolution in plants.

Anthocyanins↗
PubMedDate not supplied

Starting from fins: parallelism in the evolution of limbs and genitalia. The fin-to-limb transition.

The March/April 2002 issue of Evolution and Development focused on three presentations made at the Starting from Fins: Parallelism in the Evolution of Limbs and Genitalia symposium held as part of the 2001 Chicago meeting of the Society of Integrative and Comparative Biology. The intention of the symposium and the publication of the presentations was to extend discussion of the potential and the limits of using serial homologues to understand developmental aspects of morphological evolution. The March/April 2002 issue concentrated on unpaired fin to genitalia transitions. This issue focuses on paired fins to limbs and highlights the need for developmental data to be integrated with data from fossil materal, phylogenetic analysis, and explicitly comparative studies. Coates et al. use phylogenetic methods to explore the limb/fin characters of taxa, but their analysis departs somewhat from the usual in that the reference group for organisms includes sister group taxa not usually considered true tetrapods. They state that including finned taxa from the stem group permits an attempt to distinguish the primitive condition of the characteristics demonstrated by the crown group, that is, "limbed tetrapods." In focusing on limb characters specifically and including aspects of the appendicular girdles, Coates et al. highlight morphological details and trends within a given phylogeny. They also demonstrate the degree of relevance of limb characters during the establishment of lineages and their branching patterns by using only limb characters to generate a tree and use a direct comparison of serial versus special homologies to explore the degree of evolutionary parallelism between fore-and hindlimbs. The preliminary conclusions indicate a high level of independence between the serially homologous fore-and hindlimb. Innes et al. present outcomes from the use of cutting edge molecular genetic approaches to understand developmental aspects of limb morphology. In a manner conceptually similar to Coates et al.'s use of fossil characters, Innes et al. use the serial analysis of gene expression to sort differences from similarities in the gene expression profiles of fore-and hindlimbs of the same embryos. Although these gene expression pattems are likely to reflect the serial homology of the paired limbs, they are silent in terms of our understanding both the profound and subtle differences between fore- and hindlimbs in any given species. Innes et al. point out the volume of data generated by SAGE far exceeds our ability to interpret its biological meaning. The studies presented here and in the March/April issue are excellent examples of the need to interpret complex data in light of collective knowledge of evolutionary history. We hope the insights gained from the symposium and papers contribute to a dialogue on how to integrate different approaches and assist in moving forward the field of Evolution and Development.

Animals↗
PubMed1987

[Comparative anatomy of the velopharyngeal complex in mammals--excluding primates (1)].

From the anatomic element known with the man by the name of soft palatal-pharyngeal sphincter and which takes a major part in the phonation, the swallowing, the breathing, we have studied the evolutive morphology of the soft palatal-pharyngeal unity in several mammals. This unity which includes the levator palati and palatopharyngeus muscles is confirmed by the phylogenic and embryologic investigations. The comparative anatomy of the rat, rabbit, sheep and lion, allows to make obvious a evolutive line characterized by the gradual divergence of the axis of the two muscles common to the soft palatal and pharyngeal musculature, which could correspond with a phylogenic evolution.

Anatomy, Comparative↗
PubMed2002

In situ scanning tunneling microscopy of oxide-supported metal clusters: nucleation, growth, and thermal evolution of individual particles.

An experimental approach was developed for imaging the nucleation and growth of individual oxide-supported nanoparticles and their subsequent in situ chemical and thermal treatments by scanning tunneling microscopy (STM). The potential of the method is demonstrated for Au nanoparticles supported on a reduced TiO(2) substrate where a cluster-by-cluster comparison is made of the morphological evolution and stability of nanoparticles during their nucleation and thermal annealing. Using this methodology the details of the nucleation and growth kinetics can be directly observed.

Journal Article↗
PubMed2002

[Evaluation of the morphology of stapedial reflex in otosclerosis. Provoked otosclerotic stapedial reflex].

Stapedial reflex is used, amongst other pathologies, for the study of otosclerosis. In this retrospective study we have collected 188 cases of patients with otosclerosis whose diagnosis has been confirmed surgically and their first line relatives. We have performed a descriptive analysis of audiometric tests, tympanometries and ipsilateral stapedial reflexes in relation with the evolutive phase of the disease. Transmission hypoacusis has been seen in 54%, mixed hypoacusis in 29% and sensorineural hypoacusis 8% of cases. On and OFF stapedial reflexes have been seen in 18%, inverted reflexes in 46% and absent reflexes in 27% of cases. The original drawings of the different types of reflexes during the evolution of otosclerosis can be seen in the four figures shown in the study: normal reflexes; ON and OFF a, b and c types; inverted a and b; and absent reflexes. The clinical evolutive phase and the audiometric and impedance tests have been correlated. Through Chi-square (p < 0.001), we have obtained a statistical significance in relation to the use of stapedial reflexes. Also it has been suggested the use of provoked stapedial reflexes in patients with sub clinical otosclerosis in order to diagnose the disease. We conclude that the knowledge of the evolutive morphology os stapedial reflexes in otosclerosis helps diagnostic capacity.

Acoustic Impedance Tests↗
PubMed1997

Evolution of the insect body plan as revealed by the Sex combs reduced expression pattern.

The products of the HOM/Hox homeotic genes form a set of evolutionarily conserved transcription factors that control elaborate developmental processes and specify cell fates in many metazoans. We examined the expression of the ortholog of the homeotic gene Sex combs reduced (Scr) of Drosophila melanogaster in insects of three divergent orders: Hemiptera, Orthoptera and Thysanura. Our data reflect how the conservation and variation of Scr expression has affected the morphological evolution of insects. Whereas the anterior epidermal expression of Scr, in a small part of the posterior maxillary and all of the labial segment, is found to be in common among all four insect orders, the posterior (thoracic) expression domains vary. Unlike what is observed in flies, the Scr orthologs of other insects are not expressed broadly over the first thoracic segment, but are restricted to small patches. We show here that Scr is required for suppression of wings on the prothorax of Drosophila. Moreover, Scr expression at the dorsal base of the prothoracic limb in two other winged insects, crickets (Orthoptera) and milkweed bugs (Hemiptera), is consistent with Scr acting as a suppressor of prothoracic wings in these insects. Scr is also expressed in a small patch of cells near the basitarsal-tibial junction of milkweed bugs, precisely where a leg comb develops, suggesting that Scr promotes comb formation, as it does in Drosophila. Surprisingly, the dorsal prothoracic expression of Scr is also present in the primitively wingless firebrat (Thysanura) and the leg patch is seen in crickets, which have no comb. Mapping both gene expression patterns and morphological characters onto the insect phylogenetic tree demonstrates that in the cases of wing suppression and comb formation the appearance of expression of Scr in the prothorax apparently precedes these specific functions.

Amino Acid Sequence↗
PubMed2002

Arthropod Hox genes: insights on the evolutionary forces that shape gene functions.

Comparative studies suggest that gene duplication, changes in cis-regulatory elements and changes in protein sequence all contribute to the evolution of Hox gene functions, but the evolutionary dynamics of these changes are probably different. It seems likely that gene duplications arise as neutral changes and acquire an adaptive significance later on. By contrast, some changes in regulatory and protein-coding sequences can have immediate consequences in morphological evolution.

Animals↗