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P Coelho

Publications and source records attributed to P Coelho.

8 recordsLinked to original sources
PubMed2000

The Drosophila RAD21 cohesin persists at the centromere region in mitosis.

'Cohesin' is a highly conserved multiprotein complex thought to be the primary effector of sister-chromatid cohesion in all eukaryotes. Cohesin complexes in budding yeast hold sister chromatids together from S phase until anaphase, but in metazoans, cohesin proteins dissociate from chromosomes and redistribute into the whole cell volume during prophase, well before sister chromatids separate (reviewed in [1,2]). Here we address this apparent anomaly by investigating the cell-cycle dynamics of DRAD21, the Drosophila orthologue of the Xenopus XRAD21 and Saccharomyces cerevisiae Scc1p/Mcd1p cohesins [3]. Analysis of DRAD21 in S2 Drosophila tissue culture cells and live embryos expressing a DRAD21-green fluorescent protein (GFP) fusion revealed the presence of four distinct subcellular pools of DRAD21: a cytoplasmic pool; a chromosome-associated pool which dissociates from chromatin as chromosomes condense in prophase; a short-lived centrosome-associated pool present during metaphase-anaphase; and a centromere-proximal pool which remains bound to condensed chromosomes, is found along the junction of sister chromatids between kinetochores, and persists until the metaphase-anaphase transition. We conclude that in Drosophila, and possibly all metazoans, a minor pool of cohesin remains bound to centromere-proximal chromatin after prophase and maintains sister-chromatid cohesion until the metaphase-anaphase transition.

Animals↗
PubMed1999

[Comparative study of Toronto SPV prosthesis and bileaflet mechanical aortic prosthesis with 2D-Doppler echocardiography].

AIM: The aim of this study was to make a noninvasive comparison, by means of Doppler echocardiography, of the hemodynamic performance of biological stentless xenografts and mechanical bileaflet (MB) prostheses (P) in aortic position. METHODS: We studied 20 patients (pts) with normofunctional (nf) aortic Toronto (T) Stentless Porcine valves (SPV)--Group I--8 males, aged 69 +/- 12 years, 32 +/- 9 months after surgery, and 30 pts with nf MB aortic P (Carbomedics or St. Jude Medical)--Group II--17 males (p = NS vs G I), aged 61 +/- 12 years (p < 0.01 vs G I), 30 +/- 12 months after implantation (p = NS vs G I). Both groups were comparable with regard to body surface area and surgical indication. P diameters ranged from 21 to 25 mm (G I: 22.9 +/- 1.7; G II: 22.8 +/- 1.7 - p = NS), the number of pts with the same P diameter in each group being similar. We analysed, at rest: aortic orifice diameter (AoOd - cm), maximal (GMax) and mean (GMean) transprosthesic pressure gradients, P functional area (PFA) and P resistance (PRes). Gradients (mm Hg) were calculated by means of the Bernoulli equation, PFA (cm2) by means of the continuity equation and PRes (dynes.s.cm-5) as 1333 x Gmean x SEP/SV (SEP = systolic ejection period; SV = stroke volume). RESULTS: AoOd (G I vs G II): P 21--1.78 +/- 0.04 vs 2.00 +/- 0.10 (p < 0.001); P 23--1.91 +/- 0.10 vs 2.19 +/- 0.10 (p = 0.01); P 25--2.22 +/- 0.24 vs 2.29 +/- 0.19 (NS). Doppler parameters: [table: see text] CONCLUSIONS: P T SPV show better hemodynamic performance when compared to P MB with the same diameter, in aortic position. In addition, our results suggest that P T SPV allow the use of larger valve sizes for the same aortic orifice diameter.

Aged↗
PubMed1998

Cerebrospinal fluid pleocytosis and prognosis in invasive meningococcal disease in children.

BACKGROUND: The absence of cerebrospinal fluid (CSF) pleocytosis in invasive meningococcal disease (IMD) has been associated with an increased risk of death. It is unknown whether patients who lack a cellular response to central nervous system (CNS) infection are at the same risk of adverse outcome as patients who lack CNS infection. OBJECTIVES: To determine the frequency of presentation and outcome of three groups of children with IMD: Group 1, children with CSF pleocytosis; Group 2, children without CSF pleocytosis and with negative CSF cultures (bacteremia alone); and Group 3, children without CSF pleocytosis but with positive CSF cultures (CNS infection without CSF pleocytosis). METHODS: We reviewed the medical records of children with IMD at four pediatric referral hospitals between 1985 and 1996. Clinical and laboratory indices and severe adverse outcomes (defined as death or limb loss) were compared in the three groups. Multivariable logistic regression analysis was performed to determine whether CNS infection without CSF pleocytosis was independently associated with adverse outcome in IMD. RESULTS: Three hundred seventy-seven children with IMD were identified. Eighty-six patients were excluded because their CSF analysis either was not done or was unevaluable; of these patients 22 (25.6%) had an adverse outcome. Of the 291 evaluable patients 204 (70.1%) had CSF pleocytosis, 52 (17.9%) had bacteremia alone and 35 (12.0%) had CNS infection without CSF pleocytosis. Patients with CNS infection without CSF pleocytosis had significantly lower white blood cell and platelet counts and more coagulopathy than patients with bacteremia alone (P < or = 0.05) or patients with CSF pleocytosis (P < or = 0.01). The frequency of adverse outcome was 40% for patients with CNS infection without CSF pleocytosis compared with 9.6% for patients with bacteremia alone (P = 0.001) and 3.4% for patients with CSF pleocytosis (P < 0.001). CNS infection without CSF pleocytosis was independently associated with adverse outcome by multivariable logistic regression analysis (P = 0.003). CONCLUSIONS: Approximately 30% of all children with IMD present without CSF pleocytosis. Of these patients those with CNS infection without pleocytosis are at higher risk of adverse outcome than either patients with CSF pleocytosis or patients with bacteremia alone.

Bacteremia↗