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PubMed2004

Taste and odor profiles (off-flavors) in the drinking waters of the Barcelona area (1996-2000).

The Aigües de Barcelona laboratory systematically monitors the organoleptic quality of the water it supplies. The water comes mainly from the Llobregat and Ter rivers, with the two sources having cleary differentiated chemical characteristics. Water is monitored by the tasting panel, which works according to FPA (Flavor Profile Analysis) principles. This paper reports the results from the period 1996-2000: characteristic organoleptic profiles, evolution of descriptors and the overall organoleptic evaluation of the water. The results show that in Llobregat water the descriptors chlorinous, medicinal, rubbery and salty are the most relevant, whereas in Ter water fresh nature/grassy and metallic are. The Aesthetic Quality Index drawn up by our laboratory confirms that Ter water has better organoleptic quality than Llobregat water. Monitoring also found that neither water lost quality significantly within the distribution network.

Cities↗
PubMed1978

[Voluminous tracheal diverticulum. One case (author's transl)].

A tracheal diverticulum, probably of congenital origin, was discovered accidentally during the course of a broncho-pulmonary affection. Diverticuli of the trachea are usually found during a simple systematic radiological examination, or when an established pulmonary condition is being investigated. Routine bronchography, alone, or associated with a tomograph, can be used to demonstrate its characteristics and precise location. Bronchoscopy may then be carried out in order to study the area surrounding the diverticular orifice more closely, and to establish the condition of its mucous lining. Several evolutive stages are involved in the pathogenesis of tracheal diverticuli, varying from a rudimentary bronchiole to megalotrachea, which, for many authors, is an autonomous condition because of its anatomical and pathological make-up, producing its own well-defined symptomatology.

Aged↗
PubMed2002

Modular evolution of a chiral auxiliary for the 1,3-dipolar cycloaddition of isomünchnones with vinyl ethers.

[reaction: see text]. The 1,3-dipolar cycloaddition reaction has long been recognized as a powerful methodology in organic synthesis. More recently, this reaction has become a popular manifold for the construction of chemical diversity. Herein, we report the development of a chiral template for the facially selective cycloaddition of isomünchnones, a common class of 1,3-dipoles. The modular format of the asymmetric unit allowed a systematic optimization of selectivity. In addition, the chiral auxiliary was removed through an unusually facile ester aminolysis.

Amino Acids↗
PubMed2005

Following the very initial growth of biological RNA viral clones.

Due to their extremely high genetic diversity, which is a direct consequence of high mutation rates, RNA viruses are often described as molecular quasispecies. According to this theory, RNA virus populations cannot be understood in terms of individual viral clones, as they are clouds of interconnected mutants, but this prediction has not yet been demonstrated experimentally. The goal of this study was to determine the fitness of individual clones sampled from a given RNA virus population, a necessary previous step to test the above prediction. To do so, limiting dilutions of a vesicular stomatitis virus population were employed to isolate single viral clones and their initial growth dynamics were followed, corresponding to the release of the first few hundred viral particles. This technique is useful for estimating basic fitness parameters, such as intracellular growth rate, viral yield per cell, rate at which cells are infected and time spent in cell-to-cell transmission. A combination of these parameters allows estimation of the fitness of individual clones, which seems to be determined mainly by their ability to complete infection cycles more quickly. Interestingly, fitness was systematically higher for initial clones than for their derived populations. In addition to environmental changes, such as cellular defence mechanisms, these differences are attributable to high RNA virus mutation rates.

Animals↗
PubMed2002

Natural product terpenoids in Eocene and Miocene conifer fossils.

Numerous saturated and aromatic hydrocarbons, but not polar compounds, originating from plants and microorganisms (biomarkers) have been reported in sediments, coals, and petroleum. Here we describe natural product terpenoids found in two fossil conifers, Taxodium balticum (Eocene) and Glyptostrobus oregonensis (Miocene). A similar terpenoid pattern is also observed in extant Taxodium distichum. The preservation of characteristic terpenoids (unaltered natural products) in the fossil conifers supports their systematic assignment to the Cypress family (Cupressaceae sensu lato). The results also show that fossil conifers can contain polar terpenoids, which are valuable markers for (paleo)chemosystematics and phylogeny.

Biological Evolution↗
PubMed1983

[Systematic neonatal screening for mucoviscidosis using an immunoreactive trypsin blood assay. Evaluation of 80,000 tests].

The development of a simple and reliable technique of trypsin radioimmunoassay in blood eluates allowed the neonatal screening for cystic fibrosis in a province of France. The study of the distribution of blood immunoreactive trypsin levels in 79,880 five day-old neonates led to choose a cut-off value of 900 micrograms/l; this choice gives a false positive rate of 3 in 1,000. The evolution of trypsin levels according to age during the first weeks of life leads to select a "two-phase" screening strategy: only neonates whose high neonatal trypsin levels persist after the second week of life (4 in 10,000) will undergo sweat test. Twenty-three cases of cystic fibrosis were diagnosed in this study, which gives an incidence of 1 in 3,470.

Cystic Fibrosis↗
PubMedDate not supplied

Flagellar apparatus absolute orientations and the phylogeny of the green algae.

The absolute orientation of the flagellar apparatus in green algal motile cells is a feature of considerable value in studies of green algal systematics and phylogeny. The absolute orientation patterns found in those algae for which this feature is known or can be deduced are reviewed. Counterclockwise absolute orientation occurs in all classes except the Chlorophyceae and is considered primitive, while the clockwise absolute orientation present in most members of the Chlorophyceae is the result of progressive clockwise rotation of components during evolution. Extant intermediates documenting this rotation include Hafniomonas vegetative cells, which show counterclockwise absolute orientation, and Chaetopeltis quadriflagellate zoospores, in which the flagellar apparatus is strictly cruciate except for a slight clockwise offset of the microtubular rootlets. The V-shaped arrangement of the basal bodies in the flagellar apparatus, as well as the presence of proximal sheaths and of two layers of scales on the cell body, further identifies the Chaetopeltis zoospore as a primitive cell type within the Chlorophyceae . Trends towards the exsertion of basal bodies from a flagellar pit, either apically or laterally, the elimination of quadriflagellate cells, and, in the Chlorophyceae , an increasing amount of basal body offset, indicate advancement within the classes. Absolute orientation is conserved during flagellar apparatus replication and development. Events after flagellar apparatus division in the algae studied may be subdivided into component assembly, which is universal and preserves phylogenetically-useful features, and component reorientation, which occurs in relatively few green algae and adapts the flagellar apparatus to specialized functions. From these flagellar apparatus orientation studies, a major reevaluation of evolution within the Chlorophyceae is proposed, with weakly- thalloid algae possessing desmoschisis (e.g. Chaetopeltis ) considered primitive, and most other types, including the Volvocales , considered more advanced. The evolution of wall formation does not preclude the formation of scales in primitive chlorophycean genera. In addition, one or more previously undescribed major lineages may exist within the green algae, including one, the Pleurastrum lineage, whose members possess dorsiventrally -flattened motile cells, counterclockwise absolute orientation of the flagellar apparatus, and a phycoplast at cytokinesis. The Chlorophyceae , the Ulvophyceae , and the Pleurastrum lineage are considered to have a common ancestor that resembled the modern genus Pyramimonas , while the Charophyceae is thought to be of more ancient derivation. Th

Chlorophyta↗
PubMed2003

The evolution of the randomized controlled trial and its role in evidence-based decision making.

The randomized controlled trial has been used in medical research for a little over half a century. This manuscript provides an overview of some of the history and evolution of the randomized controlled trial during this period. There exists hierarchies of evidence for therapeutic, diagnostic and prognostic questions, and the randomized controlled trial is at the top of the therapeutic hierarchy. Despite being at the top of the therapeutic hierarchy randomization in itself does not guarantee the trial results approximate the true effect. Issues that result in systematic and nonsystematic deviations from the truth in randomized controlled trials must also be considered. We present a model for evidence-based decision making that includes the following components: the clinical state, patient preferences, research evidence from a range of studies and clinical expertise. We discuss the role of the randomized controlled trial within evidence-based decision making.

Decision Making↗
PubMed2002

Quality of life issues in patients with essential thrombocythemia and polycythemia vera.

Essential thrombocythemia and polycythemia vera are both chronic progressive myeloproliferative disorders of insidious onset. If the excessive production of red cells and/or platelets is controlled, patients with these disorders may have prolonged survival. However, the clinical course of these patients can be complicated by a variety of events, including thrombotic episodes, bleeding episodes, arthropathies, pruritus, weakness, weight loss, neurologic impairment, erythromelalgia, fever, abdominal pain, and the life-threatening consequences of progression to myelofibrosis and/or acute leukemia. Effective control of hematopoiesis by phlebotomy or a variety of therapeutic agents has resulted in a reduction or elimination of many of these clinical events, but has not altered the evolution to myelofibrosis or acute leukemia. Use of each of these therapeutic strategies is also associated with a range of adverse events. Monitoring overall survival or a reduction in the frequency of clinical events has previously served as a means of assessing the results of these therapeutic interventions. Quality-of-life instruments have not been applied in a systematic fashion to the evaluation of outcomes in patients with these chronic myeloproliferative disorders. Quality-of-life assessments evaluate not only the state of well-being of a patient that results from an assessment of the individual's ability to perform everyday activities, which are reflective of physical, psychological, and social well-being, but also patient satisfaction with the control of disease and/or treatment-related symptoms. Quality-of-life instruments have been used to assess the clinical course of patients suffering from a variety of disorders, ranging from cancer to renal failure to chronic fatigue syndrome. Information about quality-of-life outcomes can contribute to the evaluation of variations in dose and timing of administration of therapeutic agents. It is possible that the side effects of a particular therapy may outweigh the disease regression achieved with a particular therapy. In the future, quality-of-life instruments may prove useful in prospectively evaluating therapeutic end points in patients with essential thrombocythemia and polycythemia vera.

Humans↗
PubMed1998

Mutations in a novel gene, VMD2, encoding a protein of unknown properties cause juvenile-onset vitelliform macular dystrophy (Best's disease).

Vitelliform macular dystrophy (Best's disease) is an autosomal dominant, early-onset form of macular degeneration in which the primary defect is thought to occur at the level of the retinal pigment epithelium. Genetic linkage has mapped the disease locus to chromosome 11q12-q13.1 within a 980 kb interval flanked by markers at loci D11S4076 and uteroglobin. To identify the disease gene, we systematically characterized genes from within the critical region and analysed the coding regions for mutations in 12 patients from large multigeneration Best's disease families. Following this approach, we identified a novel gene of unknown function carrying heterozygous mutations in all 12 probands. Of these, 10 result in distinct missense mutations of amino acids that are highly conserved throughout evolution, spanning a phylogenetic distance from Caenorhabditis elegans to human, and include V9M, A10T, W24C, R25Q, R218Q, Y227N, Y227C, V235M, P297A and F305S. One deletion mutation, DeltaI295, was found in two families and segregates with the disease in both cases. Northern blot analysis reveals tissue-specific expression for this gene, exclusively in the retinal pigment epithelium. In conclusion, our data provide strong evidence that mutations in the gene that we have identified cause Best's disease.

Amino Acid Sequence↗
PubMed1997

Prevalence and time trends of disabilities in school-age children.

BACKGROUND: Although the evolution of the prevalence of cerebral palsy is now well documented, much less is known about the evolution of the prevalence of other disabilities such as mental retardation, sensorial defects, autism and psychosis. The aim of this paper is to determine those trends. METHODS: A population-based survey was carried out in 1992-1993 in three French 'départments'. All disabled children born between 1976 and 1985 and receiving a special education and/or financial assistance were systematically registered. RESULTS: The comparison of three cohorts of children born in 1976-1978, 1979-1981 and 1982-1984 using the test for trend in proportion showed a significant decrease (P = 0.03) in the prevalence of severe mental retardation, after exclusion of Down syndrome. This decrease was significant for severe mental retardation associated with psychosis. The time trend prevalence for cerebral palsy increased (P = 0.03) but was irregular. The time trend prevalence of other disabilities (other motor defects, severe sensorial disabilities, autism and psychosis) did not change significantly. A detailed analysis of severe mental retardation and cerebral palsy was performed by geographical area, age at first registration and type of disability. CONCLUSION: The increase in prevalence of cerebral palsy is possibly due to earlier registration of disabled children. The decrease in prevalence of severe mental retardation does not seem to be due to recruitment bias, but there is a possibility of classification bias.

Adolescent↗
PubMed1999

Unified projection operator formalism in nonequilibrium statistical mechanics.

The method of projection operators, which plays an important role in the field of nonequilibrium statistical mechanics, has been established with the use of the Liouville-von Neumann equation for a density matrix to eliminate irrelevant information from a whole system. We formulate a unified and general projection operator method for dynamical variables. The main features of our formalism parallel those for the Liouville-von Neumann equation. (1) Two types of basic equations, time-convolution and time-convolutionless decompositions, are systematically obtained without specifying a projection operator. (2) Expansion formulas for both decompositions are also obtained. (3) Problems incorporating a time-dependent Liouville operator can be flexibly treated. We apply the formulas to problems in random frequency modulation and low field resonance. In conclusion, our formalism yields a more direct and easier means of determining the average time evolution of an operator than the one for the Liouville-von Neumann equation.

Journal Article↗
PubMedDate not supplied

[Varioliform gastritis: frequency and relationship with lymphocytic gastritis].

Varioliform gastritis is currently recognized as a special kind of chronic gastritis characterized by nodules, thickened fugal folds and erosions. These features appear to be unusual and different from those seen in chronic gastritis. The frequency of varioliform gastritis rarely exceeds 3% and the diagnosis can be easily made by endoscopic examination. Very little is known about the etiopathogeny, clinical significance and evolution of this disease. The role of Helicobacter pylori still remains unknown, although a close relationship between this gastritis and lymphocytic gastritis was suggested to exist over the last few years. The aim of the present study was to investigate the frequency of varioliform gastritis and its possible correlation with lymphocytic gastritis. To our knowledge, this is the first systematic study of varioliform gastritis in South America. We studied endoscopically 200 consecutive patients and found only one case of varioliform gastritis (0.5%). In a second part of the study, we examined histopathologically mucosa biopsies from 24 patients with varioliform gastritis and studied the presence of intraepithelial lymphocytes to verify the presence of lymphocytic gastritis. No case was found. We conclude that there was no correlation between varioliform gastritis and lymphocytic gastritis in our patients.

Adolescent↗
PubMed2000

The evolution of instrumentation and obturation leading to a simplified approach.

The evolution of endodontic treatments has included the introduction of rotary crown-down nickel-titanium instrumentation and the use of thermoplasticized gutta percha to obturate canals. Although these techniques have provided dentists with solutions to problems encountered with earlier generation endodontic procedures, they have also presented deficiencies that are now receiving some critical review. As a result, a systematic technique has been developed that provides a simplified approach for root canal instrumentation and predictable obturation. This article reviews the aspects of earlier endodontic techniques and provides the step-by-step clinical protocol involved with simplified endodontic techniques.

Dental Alloys↗
PubMedDate not supplied

Occupational health nurses and case management.

Employers, providers, consumers, regulators, and society are demanding a systematic method to determine quality and cost efficiency in the provision of health care services in a multidisciplinary continuum of care within a reasonable time limit. Societal and legislative pressure on employers to incorporate and accommodate workers with disabilities or limitations and rising health insurance costs have urged organizations to set up effective strategies. An overview of the historical evolution of case management, trends in engaging workers in a successful return to work process, and a case study are presented.

Case Management↗
PubMed1991

Parasitology in East Germany--roots, period of the G.D.R., future.

The paper starts with a historical reflection on the region and on famous scientific personalities which worked up parasitological problems on the territory of East Germany. Native scientists like J. L. Frisch, C. A. Rudolphi, R. Leuckart, A. C. Gerlach, R. Virchow, R. Koch, R. von Ostertag, W. Nöller, R. Wetzel made in fundamental contributions to the growth of knowledge in General and Special Parasitology. The parasitological institutions existing in East Germany are represented briefly. The parasitologists of East Germany, nearly 160,--biologists, physicians and veterinarians--among them more than 50 specialized parasitologists were associated in the Parasitological Society of the G.D.R. since 1961. A review is given of actual parasitological problems of agricultural and other domestic animals, fair game animals, of bees and freshwater fish as well as of the most important parasitoses of man frequent in East Germany, under the aspects of epidemiology, diagnosis and control. The rapid evolution of an intensive animal production under large scale management conditions required a permanent control of infestation with pathogenic protozoans, arthropods and helminths. Some selected results achieved in research and practice are represented. The epidemiological situation referring to parasitic zoonoses is favourable at present. Since 1970 a group of experts from East Germany working successfully in Mongolia on the systematic control of ectoparasites of farm animals together with Mongolian parasitologists. It is considered to be necessary to make an international agreement in parasitological research in future more than till now.

Germany↗