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PubMed1989

[Primary malignant melanoma of ORL mucosa. Apropos of 5 cases].

Based on five observations of primary mucosal melanomas recently treated in the department, the authors describe the main features of this very rare condition, and particularly the evolutive aspects in diagnosis and prognosis. Histological diagnosis is sometimes difficult, and must involve specific argentic staining and a search for the presence of the protein S100. Tumor thickness was systematically examined. No prognostic interpretation, however, is possible, given the small number of cases in the series. Evolution is unpredictable; there is very commonly a series of local recurrences which may be well controlled, followed by remote metastases remaining long quiescent, bypassing the cervical ganglion relay. Treatment is surgical whenever possible, with palliative radiotherapy for local recurrences and chemotherapy for metastatic forms. Other therapies have yet to prove their effectiveness.

Aged↗
PubMed1976

New karyological data of Rhinoderma: the chromosomes of Rhinoderma rufum.

The chromosomes of the Chilean frog Rhinoderma rufum are described for the first time. This chromosome set is compared with the karyotype of R. darwinii. The importance of the karyological data applied to the phylogeny and systematics of this genus are discussed. A tentative hypothesis of karyological evolution of Rhinoderma is given.

Animals↗
PubMed1976

Learning objectives in resident training. Objectives in clinical chemistry.

The use of learning objectives has recently found extensive application in the evolution of medical school curricula; however, they have not been utilized systematically in the education of pathology residents. In attempting to define the end-point behavior or objectives of a resident during a rotation in clinical biochemistry, 567 midwestern pathologists, clinical chemists and medical technologists working in chemistry sections rated proposed objectives as essentail, desirable but not essential, or not needed. Twenty-four of 52 objectives were considered essential for the resident to achieve by 75% or more of the respondents. These included 10 of 33 related to technical knowledge, 5 to 10 related to business and supervisory skills, 5 of 5 related to investigative problem solving, and 4 of 4 related to communicating with persons outside of the laboratory. In general, respondents considered knowledge of principles more important than technical skills. Management, business and communicative skills were highly rated.

Chemistry, Clinical↗
PubMed1991

Phylogenetic analysis of Alloglossidium Simer, 1929 (Digenea: Plagiorchiiformes: Macroderoididae) with discussion of the origin of truncated life cycle patterns in the genus.

Alloglossidium comprises 9 species of North American plagiorchiiform digeneans using ictalurid catfish, freshwater crustacea, and hirudinid leeches as definitive hosts. Two hypotheses about the evolution of this array of definitive hosts were examined using phylogenetic systematic analysis. Two most parsimonious trees, based on 15 homologous series derived from morphological data, each indicated the 2 species utilizing ictalurid catfish definitive hosts are basal members of the group, whereas the 2 species using freshwater crayfish definitive hosts and the 5 utilizing leech definitive hosts each comprise relatively derived monophyletic sister groups. The results suggest that species using crustaceans as definitive hosts are derived by life cycle truncation, whereas those using leeches as definitive hosts appear to be derived through a switch from crustaceans to leeches.

Animals↗
PubMed1993

[Sideroses of alveolar macrophages. Analysis of a continuous series of 360 bronchoalveolar lavages].

360 consecutive bronchoalveolar lavage fluids (BAL) were studied using semi-quantitative method described by GOLDE (GOLDE score). 44 hemosiderosis were detected (12%). Most of them corresponded to massive alveolar hemorrhage (AH). Depending on pathological contexts, we distinguished three main groups of AH frequency: a group of high frequency (around 40%), an intermediate group (10%) and a low frequency group with less than 5%. Matching cytological results with clinical and radiological data, revealed that AH was often too late diagnosed because inconstancy of typical clinical and radiological signs. Even with a variable prognosis related to different physiopathological mechanisms, AH evolution is unpredictable. The authors suggest thus BAL cytological examination may systematically include a research of hemosiderosis in AH high frequency groups.

Acquired Immunodeficiency Syndrome↗
PubMed1993

[The Griscelli-Prunieras syndrome: a case report].

It is presented a six-year-old girl with silvered hair syndrome, of Griscelli-Prunieras variety; hereditary sickness with regressive autosomic and distinguished by partial albinism and leukocytic alterations. She presented the acute phase of the sickness distinguished by: hepatosplenomegaly, thrombocytopenia, lymphadenopathy generalized, and systematic infection; it is corroborated how a hemophagocytic syndrome; during her evolution developed pancerebellar syndrome. By laboratory were corroborated: decrease phagocytosis, degranulation 0%, decrease of globulins gamma, neutropenia, skin test of PPD and Candidin negatives, there were not find the giant inclusions in bone marrow leukocyte and peripheric blood that are feature of Chediak-Higashi syndrome. Another alteration that was the distribution of mote of melanin on the hair that in the Griscelli-Prunieras syndrome are six times bigger in the Chediak-Higashi syndrome.

Acute Disease↗
PubMed1994

Archaebacterial genomes: eubacterial form and eukaryotic content.

Since the recognition of the uniqueness and coherence of the archaebacteria (sometimes called Archaea), our perception of their role in early evolution has been modified repeatedly. The deluge of sequence data and rapidly improving molecular systematic methods have combined with a better understanding of archaebacterial molecular biology to describe a group that in some ways appears to be very similar to the eubacteria, though in others is more like the eukaryotes. The structure and contents of archaebacterial genomes are examined here, with an eye to their meaning in terms of the evolution of cell structure and function.

Archaea↗
PubMed1993

[Alzheimer's disease followed in a single case].

Descriptions of Alzheimer's disease are usually based on the observation of populations of patients. Their advantage is the systematic analysis of signs and symptoms according to a logical approach enumerating the involvement of neurological, neuropsychological, affective and behavioral fields. Their disadvantage is to neglect the natural evolutive way and the subtle gearing of these diverse aspects of the disease. This paper aspires to bring a complement to the necessary systematic knowledge, by the description of a patient who has been followed regularly every 3 months for 4 and a half years. It describes the evolution as it is lived by the patient and his spouse, and as it is observed by the clinician. Three main facts are inferred. The first is the precocious involvement of two functions particularly affected later: language and the ability of identifying others. The second is with the evolution of the disease the identification, in the neuropsychological domain, of some tests which show no or little alteration, of some others altered from the outset, the majority deteriorating progressively. The third is the observation of a brisk and definitive worsening following a transient ischemic attack, demonstrating the vulnerability of these patients when the disease has reached an advanced stage.

Activities of Daily Living↗
PubMed1998

Analogous enzymes: independent inventions in enzyme evolution.

It is known that the same reaction may be catalyzed by structurally unrelated enzymes. We performed a systematic search for such analogous (as opposed to homologous) enzymes by evaluating sequence conservation among enzymes with the same enzyme classification (EC) number using sensitive, iterative sequence database search methods. Enzymes without detectable sequence similarity to each other were found for 105 EC numbers (a total of 243 distinct proteins). In 34 cases, independent evolutionary origin of the suspected analogous enzymes was corroborated by showing that they possess different structural folds. Analogous enzymes were found in each class of enzymes, but their overall distribution on the map of biochemical pathways is patchy, suggesting multiple events of gene transfer and selective loss in evolution, rather than acquisition of entire pathways catalyzed by a set of unrelated enzymes. Recruitment of enzymes that catalyze a similar but distinct reaction seems to be a major scenario for the evolution of analogous enzymes, which should be taken into account for functional annotation of genomes. For many analogous enzymes, the bacterial form of the enzyme is different from the eukaryotic one; such enzymes may be promising targets for the development of new antibacterial drugs.

Amino Acid Sequence↗
PubMed1989

Gross morphology and evolution of the mechanoreceptive lateral-line system in teleost fishes.

The morphology and development of the mechanoreceptive lateral-line system in teleost fishes is reviewed, and the systematic distribution of defined types of lateral-line systems is summarized. The importance of an understanding of ontogeny is stressed and the roles of phylogenetic and developmental constraints in the evolution of the lateral-line system are discussed. Four types of head canal systems are identified on the basis of the relative development of the canals and the orientation of the neuromast receptors contained within them. The distribution of these patterns in the four major teleost clades is analyzed. It is suggested that a branched tubule system associated with the head canals is a primitive teleost character, while widened and reduced head canal patterns are convergent functional specializations in many taxa. The trunk canals are contained in a continuous series of lateral-line scales, and eight trunk canal patterns are described in teleosts. Given the correlation of the systematic distribution of the different trunk canal patterns, ecological habit and body shape, it appears that the trunk canals may function as a hydrodynamic monitor in swimming fishes.

Animals↗
PubMed1995

The evolution of haematopoietic cytokine/receptor complexes.

The evolutionary expansion of the haematopoietic cytokines and their receptors is characterized by the duplication of both cytokines and receptors. A systematic analysis of primary sequence homology indicates that receptors for gp130-associated cytokines group into signal transducing and non-signal transducing receptors. This observation is consistent with the evolution of the interleukins 6, 11 and 12, granulocyte colony stimulating factor (G-CSF), leukemia inhibitory factor (LIF), oncostatin M, and the ciliary neurotrophic factor complexes from a common ancestral complex which included a homodimer of gp130-like signalling receptors and an interleukin 6 receptor-like non-signalling receptor. Alterations in the components of the complex are proposed to have arisen by receptor duplication and divergence to allow signal transduction via a LIF receptor/gp130 heterodimer, and loss of the non-signalling receptor component in the G-CSF and the LIF lineage. The short-chain haematopoietins and their receptors do not group clearly, although interleukins 4 and 13 grouped together, as did 2 and 10. Internal duplication of the ligand-binding domain appears to have occurred independently in three separate lineages. These observations have implications for the classification of cytokines and receptors, and for the modelling by homology of their structures and interactions.

Amino Acid Sequence↗
PubMed1998

Molecular epidemiology of enteroviruses with special reference to their potential role in the etiology of insulin-dependent diabetes mellitus (IDDM). A review.

BACKGROUND: Several lines of evidence suggest that enterovirus infections may be involved in the etiology of the insulin-dependent diabetes mellitus (IDDM). Often in the literature, a reference is given to specifically diabetogenic strains of enterovirus but there is no systematic assessment about the generation of such strains in the course of evolution or about their abundance among the 64 enterovirus serotypes pathogenic to man. If enteroviruses truly are involved in the etiology of IDDM, a possibility to prevent the disease with enterovirus vaccines might become feasible. In such a situation it would be important to know which serotypes and strains are the most important ones, and whether there would be differences between the strains as regards the pathogenetic mechanisms involved. OBJECTIVE: To present a brief summary of the basic biology of enteroviruses, on existing data of genetic variation of enteroviruses, and on molecular epidemiology of human enteroviruses with special reference to the different epidemiological modes of their putative involvement in the pathogenesis of IDDM. CONCLUSIONS: Like RNA viruses in general, enteroviruses exist as a quasispecies, a mixture of genetic microvariants with a vast potential to adapt to new environments. This means that specifically beta cell-tropic and potentially diabetogenic variants could, in theory, emerge sporadically during systemic infection of any individual. The patterns of genetic diversification of enteroviruses, cocirculation of separate genetic lineages in the human populations, and the assumed geographical restrictions of endemic transmission of the lineages, allow one to hypothesize that populations with a high persisting IDDM incidence might be endemically infected by some specific strains of enteroviruses. However, so far, there is no systematically collected data supporting this hypothesis.

Amino Acid Sequence↗
PubMed1982

Functional morphology of beta cells in the area centralis of the cat's retina: a model for the evolution of central retinal specializations.

The dendritic morphology of beta cells in and around the area centralis of the retinae of normally pigmented and Siamese cats is described. Individual central beta cells in the Siamese cat do not differ morphologically from central beta cells in normally pigmented cats, and in both groups of animals, there is a clear morphological continuity between central and peripheral beta cells. On the basis of systematic patterns of beta cell dendritic orientation, ther area centralis of the normal cat can be divided into a central region, approximately 200 micrometers in diameter, and a pericentral region, approximately 1,400 micrometers in diameter. In the central region, nearly all beta cells have a single large primary dendrite which descends perpendicular to the plane of inner plexiform layer, and gives rise to a dendritic tree which is vertically aligned with the cell's soma. In the pericentral region, the single primary dendrite of most cells descends obliquely through the inner plexiform layer and gives rise to a dendritic tree which is displaced laterally from the position of the soma. For most of the cells the trajectory of the dendrite is systematically related to the location of the cell relative to the area centralis such that the somas are displaced away from its center, presumably in order to minimize the thickness of the ganglion cell layer in the high acuity region. Many beta cells outside the pericentral region also have oriented single primary dendrites, but their orientation seems fairly random with respect to the location of the area centralis. In the Siamese area centralis, this systematic pattern of beta cell dendritic orientation is markedly reduced, suggesting that the pattern is under genetic control. On the basis of these observations, a model for the evolution of the area centralis and fovea is presented which involves selection for systematic for systematic patterns of dendritic orientation in regions of high ganglion cell density.

Animals↗
PubMed1995

[Evolution of the susceptibility to penicillin G of Streptococcus pneumoniae at the Limoge University Hospital Center].

A systematic detection of Streptococcus pneumoniae strains with reduced susceptibility to penicillin has been realized at Limoges Hospital during two years half. Of 302 strains isolated, 27 had reduced susceptibility to penicillin (8,9%), and, for 15 strains (5%), the MIC of penicillin G reached at least 2 mg/l. The frequency of strains with reduced susceptibility to penicillin increased from 1992 to 1994: 8,2% in 1992, 8,7% in 1993 and 12,2% in 1994. The resistance level exhibited by pneumococcus strains increased since 1992: the percentage of resistant strains (MIC mg/l > 1) was 2,7% in 1992, 6,9% in 1993 and 7,3% in 1994. Most of the strains with reduced susceptibility to penicillin belonged to serotype 23 (52%) and were isolated from blood cultures, cerebral-spinal or pleural fluids (41%).

France↗
PubMed1993

The systematics of nematodes that cause ostertagiasis in domestic and wild ruminants in North America: an update and a key to species.

Studies of medium stomach worms (Subfamily Ostertagiinae) of domestic and wild ruminants in North America have refined our understanding of the systematics, host distribution and biogeography of these nematodes. Strong support for recognition of monophyly for the Ostertagiinae has resulted from preliminary phylogenetic analyses of morphological characters among these and other trichostrongylids. Evaluation of morphological and biochemical characters in our laboratory and elsewhere has not refuted the polymorphism hypothesis where paired major and minor morphotypes are postulated to represent polymorphic species within the genera Ostertagia (Ostertagia ostertagi/Ostertagia lyrata; Ostertagia leptospicularis/Ostertagia kolchida; Ostertagia gruehneri/Ostertagia arctica; Ostertagia mossi/Ostertagia dikmansi), Teladorsagia (Teladorsagia circumcincta/Teladorsagia trifurcata (= Teladorsagia davtiani), and Marshallagia (Marshallagia marshalli/Marshallagia occidentalis). The minor morphotype of Ostertagia bisonis, recognized in Eurasia (considered to be Teladorsagia kazakhstanica), has yet to be discovered in North America. The taxonomy of these species has remained stable since an earlier overview of Ostertagia spp. and Teladorsagia spp. in North American domestic stock at the 1986 Ostertagia Workshop. Investigations since 1986 have focused on comparative morphology and the clear differentiation of Ostertagiinae, primarily from wild ruminants, that have been reported or may potentially occur in domestic bovids. Among these are species which infect wild and domestic sheep (Marshallagia marshalli/Marshallagia occidentalis), bovids (Ostertagia bisonis), and cervids (Ostertagia mossi/Ostertagia dikmansi, Ostertagia leptospicularis/Ostertagia kolchida, Ostertagia gruehneri/Ostertagia arctica, Mazamastrongylus odocoilei and Mazamastrongylus pursglovei) in North America. A key is presented for identifying 15 species of the Subfamily Ostertagiinae that are parasitic in domestic and wild ruminants of North America. Four exotic species (Camelostrongylus mentulatus, Spiculopteragia spiculoptera (= Spiculopteragia boehmi), Spiculopteragia asymmetrica and Longistrongylus curvispiculum) have been reported in North America, but only in game farms and are not included in the key. Hyostrongylus rubidus, a member of the Ostertagiinae normally parasitic in pigs and only rarely reported from domestic ruminants, is not included in the keys. Additional data from comparative morphology and molecular analyses will promote a reassessment of the generic-level systematics of the Ostertagiinae and allow an evaluation of host-parasite evolution and historical biogeography.

Animals↗
PubMed1998

Transmission pattern of hobo transposable element in transgenic lines of Drosophila melanogaster.

This study is an attempt to trace the fate of hobo elements in the genomes of E strains of Drosophila melanogaster that have been transfected with pHFL1, a plasmid containing an autonomous hobo. Such long-term population studies (over 105 generations) could be very useful for better understanding the population and genomic dynamics of transposable elements and their pattern of insertions. Molecular analyses of hobo elements in the transfected lines were performed using Southern blots of XhoI-digested genomic DNAs. The complete element was observed in all six injected lines. In two lines we observed, at generation 100, two deleted elements, which did not correspond to Th1 and Th2. The results obtained by the in situ method show that the number of hybridization sites increases in each line and prove that the hobo element may be amplified in an RM genome. The hobo activity does not seem to be systematically correlated with the number of hobo elements. After generation 85, the evolution of the hobo element's insertion site number depends on the injected line. In all lines, the total number of insertions remains quite small, between 0 and 11. Hobo elements are located on each of the chromosomal arms. We describe 'hotspots'-insertion sites present in all lines and in all generations. On the 3R arm, a short inversion appeared once at generation 85.

Animals↗
PubMed1995

L1 (LINE-1) retrotransposable elements provide a "fossil" record of the phylogenetic history of murid rodents.

The single most difficult problem in phylogenetic analysis is deciding whether a shared taxonomic character is due to common ancestry or one that appeared independently due to convergence, parallelism, or reversion to an ancestral state. Mammalian L1 retrotransposons undergo periodic amplifications in which multiple copies of the elements are interspersed in the genome. Because these elements apparently are transmitted only by inheritance and are retained in the genome, a shared L1 amplification event can only be an inherited ancestral character. We propose that L1 amplification events can be an excellent tool for analyzing mammalian evolution and demonstrate here how we addressed several refractory problems in rodent systematics using L1 DNA as a taxonomic character.

Animals↗