Search PubMed⌕ Search

Biomedical subjects

C Vieira

Publications and source records attributed to C Vieira.

32 records · Page 2Linked to original sources
PubMed1998

Can a large institution go paperless?

Since 1989, Beth Israel Hospital has been deploying an extensive online patient record (the OMR), which augmented a heavily used integrated hospital information system. Initially begun in a large primary care practice, the system is now used to share patient records among 36 practices on three campuses. Although the system was intended to eliminate the need for paper, we have found that it has, in the short term, increased the amount of paper produced. Elimination of paper record in ambulatory care has saved us $56,000, but we have yet to realize the savings of an additional $200,000 per year. We explore the factors that contribute to this "paper paradox" and discuss the costs associated with increased paper production, areas in which we have reduced paper handling, and strategies for reducing our reliance on paper.

Academic Medical Centers↗
PubMed1997

Chromosomal distribution of the 412 retrotransposon in natural populations of Drosophila simulans.

The insertion site localization of the 412 retrotransposable element was analysed by in situ hybridization to the polytene chromosomes of 57 individual genomes from 25 natural populations of Drosophila simulans. The 412 insertion sites along the chromosomes show a tendency to aggregate in the distal and proximal ends of the 2R arm, and in several local regions along the 3R arm. The distribution of the 412 insertion sites, weighted by DNA content, along the chromosome arms reveals an overall tendency for the site number to increase from the middle of the arm to the base and tip, with a decrease at the tips, especially pronounced for the X chromosome. Such a distribution differs slightly from that of D. melanogaster, which globally shows an increase of the 412 site number from base to tip of the chromosome arms, indicating differing behaviour of the 412 element in the two species. These results are discussed in connection with the recombination rate along the chromosome arms.

Animals↗
PubMed1997

A preliminary assessment of the recombinant antigen PLA2 in the diagnosis of human dirofilariosis.

Two recombinant antigens (P22U and PLA2), cloned in a L4 Dirofilaria immitis cDNA library, were analyzed by Western-blot and ELISA to investigate their characteristics for the diagnosis of human dirofilariosis. P22U seems related to a Di22 native antigen useful for the diagnosis of pulmonary dirofilariosis, but it is unspecifically recognized by sera from patients with different parasitic and non parasitic pulmonary diseases. PLA2 is not related to Di22 but specifically reacts in Western-Blot and ELISA with sera from patients with subcutaneous dirofilariosis.

Antigens, Helminth↗
PubMed1997

Transposition rate of the 412 retrotransposable element is independent of copy number in natural populations of Drosophila simulans.

The transposition and excision rates of the 412 retrotransposable element were estimated in five populations of Drosophila simulans differing in their average 412 copy numbers, which ranged from 2 to 54. The transposition rate was found to equal 1 x 10(-3) to 2 x 10(-3), independently of copy number. No excision was detected. These values eliminate autoregulation as a force maintaining copy number of the 412 element in natural populations of D. simulans.

Animals↗
PubMed1997

Maintenance of transposable element copy number in natural populations of Drosophila melanogaster and D. simulans.

To investigate the main forces controlling the containment of transposable elements (TE) in natural populations, we analyzed the copia, mdg1, and 412 elements in various populations of Drosophila melanogaster and D. simulans. A lower proportion of insertion sites on the X chromosome in comparison with the autosomes suggests that selection against the detrimental effects of TE insertions is the major force containing TE copies in populations of Drosophila. This selection effect hypothesis is strengthened by the absence of the negative correlation between recombinaiton rate and TE copy number along the chromosomes, which was expected under the alternative ectopic exchange model (selection against the deleterious rearrangements promoted by recombination between TE insertions). A cline in 412 copy number in relation to latitude was observed among the natural populations of D. simulans, with very high numbers existing in some local populations (around 60 copies in a sample from Canberra, Australia). An apparent absence of selection effects in this Canberra sample and a value of transposition rate equal to 1-2 x 10(-3) whatever the population and its copy number agree with the idea of recent but temporarily drastic TE movements in local populations. The high values of transposition rate in D. simulans clearly disfavor the hypothesis that the low amount of transposable elements in this species could result from a low transposition rate.

Animals↗
PubMed1996

Geographical variation in insertion site number of retrotransposon 412 in Drosophila simulans.

The insertion site number of the retrotransposable element 412 was analyzed in natural populations of Drosophila simulans of worldwide origin by in situ hybridization. We observe a gradient in copy number ranging from as high as 23 in Europe to 1-10 in South Africa, while populations in Madagascar and the Indian Islands, which are the cradle of D. simulans, have only 3-7 copies. We find very different copy numbers in some local populations of Australia and the Pacific Islands (with around 60 copies in 1 sample and only 5 in another), suggesting spontaneous transposition bursts in local populations. Such bursts occurring now and then in local natural populations followed by fly migration could lead to the progressive invasion of the entire species by the transposable element mobilized, explaining the gradient in 412 copy number between northern and southern hemispheres.

Animals↗
PubMed1996

Selection against transposable elements in D. simulans and D. melanogaster.

The insertion site numbers of the transposable elements (TEs) copia, mdg1, 412 and gypsy were determined in various natural populations of Drosophila melanogaster and D. simulans by in situ hybridization. We showed that, while all elements except gypsy had many insertion sites scattered over the chromosomes in D. melanogaster, only the 412 element in D. simulans presented a high number of insertions, and this number was lower than in D. melanogaster. This low 412 site number per genome in D. simulans was associated with a lower proportion of insertions on the X chromosome in comparison with D. melanogaster, as determined in diploid genomes (0.090 for D. simulans against 0.137 for D. melanogaster) and in haploid genomes (0.102 against 0.146), each value being, moreover, lower than the value of 0.20 expected on the hypothesis of no selection against insertional mutations. These results suggest that selection is a major mechanism explaining 412 copy number regulation in Drosophila, and is stronger in D. simulans than in D. melanogaster.

Animals↗
PubMed1993

Association between puberty and delayed phase preference.

Many teenagers go to bed and wake up significantly later than younger children, a developmental progression thought to reflect adolescent psychosocial processes. To determine whether biological processes may underlie a delay of phase preference in adolescents, 183 sixth-grade boys and 275 sixth-grade girls completed questionnaires for morningness/eveningness (M/E) and pubertal status. School environment and birth order were also evaluated. A significant relationship of pubertal status to M/E was found in girls, with a similar though nonsignificant trend in boys. No relationship between M/E and psychosocial factors was found. These data support involvement of a biological factor in the adolescent phase preference delay and indicate that our current understanding of adolescent sleep patterns may need revision.

Adolescent↗
PubMedDate not supplied

[Spending and financing in health care: situation and trends].

Being knowledgeable about national health expenditures and sources of financing is essential for decision-making. This awareness also makes it possible to evaluate the equity of allocation and the efficiency of utilization of these resources. Changes in financing have been a substantial component of health sector reform in the Americas. The goal has shifted from merely one of financial sustainability to simultaneously seeking equitable access to quality services. In this article the Pan American Health Organization (PAHO) presents a proposal for analyzing and designing a policy on health financing. The aim of the policy is to identify the mix of financing mechanisms most likely to simultaneously produce financial sustainability, equity, access, and efficiency. The PAHO proposal combines traditional mechanisms for generating resources (public funds from taxes, as well as private health insurance, national health insurance, and user fees) with complementary subsidy mechanisms for vulnerable groups. Health financing strategies ought to explicitly consider the financing both of care for individuals and of health interventions for the general public good, for which public financing is the most equitable and efficient approach.

Americas↗
PubMedDate not supplied

Multiresidue method for determination of eight neutral beta-lactam penicillins in milk by fluorescence-liquid chromatography.

A method of determining total penicillins begins with an enzymatic hydrolysis of the beta-lactam ring to form their respective penicilloate product. Acetonitrile precipitates much of the casein and protein, which are then separated from the liquid by centrifugation. The lipids are removed from the aqueous fraction with methylene chloride. Mercuric chloride is added, which reacts with the penicilloate to liberate the side chain that has a terminal aldehyde. These penilloaldehyde products are extracted with methylene chloride and are subsequently reacted with dansyl hydrazine. The resulting fluorolabeled side chains are separated by liquid chromatography on a C18 column with acetonitrile-water as mobile phase. The fluorescence is measured by the mercury line at 254 nm excitation wavelength and a 500 nm filter on the emission side. The overall average recoveries from milk spiked at 25, 50, and 100 ppb are benzyl penicillin 79.4%; phenoxymethyl penicillin 59.7%; phenethicillin 75.9%; nafcillin 87.7%; methacillin 47.5%; oxacillin 57.6%; cloxicillin 37.3%; and dicloxicillin 26.4%.

Animals↗