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M De Robertis

Publications and source records attributed to M De Robertis.

10 recordsLinked to original sources
PubMed2000

MitBASE : a comprehensive and integrated mitochondrial DNA database. The present status.

MitBASE is an integrated and comprehensive database of mitochondrial DNA data which collects, under a single interface, databases for Plant, Vertebrate, Invertebrate, Human, Protist and Fungal mtDNA and a Pilot database on nuclear genes involved in mitochondrial biogenesis in Saccharomyces cerevisiae. MitBASE reports all available information from different organisms and from intraspecies variants and mutants. Data have been drawn from the primary databases and from the literature; value adding information has been structured, e.g., editing information on protist mtDNA genomes, pathological information for human mtDNA variants, etc. The different databases, some of which are structured using commercial packages (Microsoft Access, File Maker Pro) while others use a flat-file format, have been integrated under ORACLE. Ad hoc retrieval systems have been devised for some of the above listed databases keeping into account their peculiarities. The database is resident at the EBI and is available at the following site: http://www3.ebi.ac.uk/Research/Mitbase/mitbas e.pl. The impact of this project is intended for both basic and applied research. The study of mitochondrial genetic diseases and mitochondrial DNA intraspecies diversity are key topics in several biotechnological fields. The database has been funded within the EU Biotechnology programme.

Animals↗
PubMed1999

MitBASE: a comprehensive and integrated mitochondrial DNA database.

MitBASE is an integrated and comprehensive database of mitochondrial DNA data which collects all available information from different organisms and from intraspecie variants and mutants. Research institutions from different countries are involved, each in charge of developing, collecting and annotating data for the organisms they are specialised in. The design of the actual structure of the database and its implementation in a user-friendly format are the care of the European Bioinformatics Institute. The database can be accessed on the Web at the following address: http://www.ebi.ac. uk/htbin/Mitbase/mitbase.pl. The impact of this project is intended for both basic and applied research. The study of mitochondrial genetic diseases and mitochondrial DNA intraspecie diversity are key topics in several biotechnological fields. The database has been funded within the EU Biotechnology programme.

Animals↗
PubMed1999

Update of AMmtDB: a database of multi-aligned metazoa mitochondrial DNA sequences.

The present paper describes AMmtDB, a database collecting the multi-aligned sequences of vertebrate mitochondrial genes coding for proteins and tRNAs, as well as the multiple alignment of the mammalian mtDNA main regulatory region (D-loop) sequences. The genes coding for proteins are multi-aligned based on the translated sequences and both the nucleotide and amino acid multi-alignments are provided. As far as the genes coding for tRNAs are concerned, the multi-alignments based on the primary and the secondary structures are both provided; for the mammalian D-loop multi-alignments we report the conserved regions of the entire D-loop (CSB1, CSB2, CSB3, the central region, ETAS1 and ETAS2) as defined by Sbisà et al. [ Gene (1997), 205, 125-140). A flatfile format for AMmtDB has been designed allowing its implementation in SRS (http://bio-www.ba.cnr.it:8000/BioWWW/#AMMTDB ). Data selected through SRS can be managed using GeneDoc or other programs for the management of multi-aligned data depending on the user's operative system. The multiple alignments have been produced with CLUSTALV and PILEUP programs and then carefully optimized manually.

Animals↗
PubMed1999

Update of the Human MitBASE database.

Human MitBASE is a database collecting human mtDNA variants. This database is part of a greater mitochondrial genome database (MitBASE) funded within the EU Biotech Program. The present paper reports the recent improvements in data structure, data quality and data quantity. As far as the database structure is concerned it is now fully designed and implemented. Based on the previously described structure some changes have been made to optimise both data input and data quality. Cross-references with other bio-databases (EMBL, OMIM, MEDLINE) have been implemented. Human MitBASE data can be queried with the MitBASE Simple Query System (http://www.ebi.ac.uk/htbin/Mitbase/mit base.pl) and with SRS at the EBI under the 'Mutation' section (http://srs.ebi.ac.uk/srs5/). At present the HumanMitBASE node contains approximately 5000 variants related to studies investigating population polymorphisms and pathologies.

Animals↗
PubMed1988

Reduction in sudden late death by concomitant revascularization with aortic valve replacement.

To determine the impact of coronary atherosclerosis and myocardial revascularization on survival after aortic valve replacement, we reviewed our experience with single aortic valve replacement between 1969 and 1984. Of 474 patients (mean age 62 +/- 13 years), 185 (39%) had no associated coronary artery disease, 233 (49%) had coronary artery bypass grafting, and 56 (12%) had unbypassed coronary artery disease. Early (30-day) mortality rates were 2.2%, 8.2%, and 7.1%, respectively (p less than 0.01, coronary disease absent versus present). Actuarial survival rates at 10 years were 77% +/- 4%, 41% +/- 6%, and 26% +/- 11% (p less than 0.001, coronary disease absent versus present), with 1 to 177 months of follow-up (mean 56 +/- 40). Preoperative angina (39%) did not predict the presence of coronary artery disease (61%). Multivariate logistic regression analysis showed that early deaths were associated with advanced preoperative New York Heart Association functional class (p less than 0.001), advanced age (p less than 0.05), more extensive coronary artery disease (p less than 0.05), and lack of cardioplegic myocardial protection (p less than 0.05). Complete revascularization did not increase operative risk when coronary artery disease was present (early mortality 6.8%, p = not significant). Late deaths were strongly associated with the presence of coronary artery disease (p less than 0.001) and reduced left ventricular ejection fraction (less than or equal to 55%, p less than 0.01). Late cardiac mortality was most commonly attributable to sudden death (30/71, 42%), especially in the unbypassed coronary disease cohort (9/14, 64%). The actuarial rate of freedom from sudden death at 10 years was 52% +/- 17% in the unbypassed coronary artery disease group (p = 0.009), compared with 90% +/- 3% and 91% +/- 3% in the revascularized and no coronary disease patients, respectively. Thus, coexistent coronary atherosclerosis has a detrimental impact on early and late survival after aortic valve replacement. Revascularization does not increase operative risk when associated coronary artery disease is present and significantly reduces the occurrence of late sudden death. Strategies that minimize operative risk when associated coronary artery disease is present include use of cardioplegia and complete revascularization.

Adolescent↗
PubMed1987

The St. Jude valve: analysis of thromboembolism, warfarin-related hemorrhage, and survival.

From March 1978-86, 590 St. Jude prostheses (232 aortic, 232 mitral, and 63 double aortic-mitral) were implanted in 527 patients (mean age 63 years) and followed for up to 8 years (mean 33 months; three lost; 99% complete). The early (30-day) mortality rate was 8.9% and was strongly associated with preoperatively depressed left ventricular function (ejection fraction less than 0.55), ischemic mitral regurgitation, and advanced functional class (IV) (p less than 0.05). Actuarial survival rates at 5 years were 72% +/- 4%, 72% +/- 8%, and 63 +/- 4% after aortic, double, and mitral valve replacement (p less than 0.01). There have been no structural failures. Embolism (28 events, 2.1%/patient-year) was less common with warfarin treatment (1.5%/patient-year; n = 492) than with antiplatelet (3.2%/patient-year; n = 19) or no drug therapy (18.9%/patient-year; n = 16) (p less than 0.01). One embolic event was fatal (3.6%). Warfarin-treated patients remained 91% +/- 1% free of emboli after 8 years. Valve thrombosis (six events; 0.4%/patient-year) occurred exclusively in patients not treated with effective warfarin therapy; one (17%) died. The most common complication was hemorrhage (39 events; 2.9%/patient-year); nine (23%) were fatal, and these constituted 82% of 11 valve-related late deaths. In warfarin-treated patients (target prothrombin time ratio 1.5 to 2.5), hemorrhage was twice as frequent (2.9%/patient-year) as embolism (1.5%/patient-year).(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗
PubMed1987

Intraoperative evaluation of mitral regurgitation by Doppler color flow mapping.

Excessive residual mitral regurgitation after mitral valve reconstruction or coronary artery bypass graft surgery may necessitate reoperation. We evaluated a new intraoperative technique for assessment of mitral regurgitation, real-time two-dimensional Doppler color flow mapping, in 96 patients undergoing cardiac surgery. In comparison with technically adequate preoperative left ventriculography (n = 68) obtained at a similar level of afterload (systolic arterial pressure), Doppler color flow mapping demonstrated a sensitivity of 94% (50/53) and specificity of 93% (14/15) for detection of the presence and absence of mitral regurgitation, respectively. Semiquantitative comparison of color Doppler with angiography demonstrated excellent agreement (kappa = .80, p less than .001), differing by more than one grade in two patients (3%). The pulmonary capillary wedge "V" wave pressure (absolute magnitude, and height above mean) correlated poorly with the simultaneously obtained mitral regurgitation grade by color Doppler, both before (r = .37 and .45) and after (r = .04 and -.15, p = NS) cardiopulmonary bypass. No value of the V wave clearly distinguished 3 + or 4 + regurgitation from lesser degrees of regurgitation. In 15 patients who underwent mitral valve repair, fluid filling of the ventricle was falsely positive (leak, with no regurgitation) in 40% (2/5), and falsely negative (no leak, with 2 + to 3 + regurgitation) in 30% (3/10). Regurgitation grade by color Doppler demonstrated a highly significant (p less than .01) dependence on systolic pressure, suggesting that intraoperative changes in afterload conditions importantly influence mitral regurgitation severity. Thus, Doppler color flow mapping provides accurate intraoperative evaluation of mitral regurgitation and may aid surgical decision making.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Vessel Prosthesis↗
PubMed1982

Flow characteristics of the St. Jude prosthetic valve: an in vitro and in vivo study.

The St. Jude cardiac prosthetic aortic valve was evaluated in vitro and in vivo in an attempt to establish flow characteristics and to correlate them with clinical findings. In vitro, a fluid vehicle (6% Polyol V-10, 32 degrees C) with viscosity similar to blood (0.035 dyne-sec/cm2) was used under conditions of steady flow through a flow chamber simulating the aortic root. Gradient, velocity, and shear stress were measured 5.79 mm, 26.79 mm, 44.79 mm, and 77.79 mm downstream from 25-mm and 27-mm valves using a laser-Doppler anemometer. At 417 ml/sec, the valve gradient was 6.2 mmHg with the 25-mm valve, and 5.2 mmHg with the 27-mm prosthesis. Velocity was maximum at the orifice center, and wall shear stress was low (maximum 600 dyne/cm2). In vivo, six patients with 25-mm St. Jude aortic valves were studied within 48 hours after surgery to determine cardiac output, valve flow, and gradient. The gradient was 3.3 +/- 1.9 mmHg (M +/- SD) at 249 +/- 96 ml/sec and the effective valve area was as large as the geometric area (2.58 vs. 3.09 cm2). Thus, flow through the St. Jude valve is unobstructed and central, has low turbulence, and achieves optimal effective valve area for a given available orifice area.

Aortic Valve↗
PubMed1982

Right atrial tamponade complicating cardiac operation: clinical, hemodynamic, and scintigraphic correlates.

Persistent bleeding into the pericardial space in the early hours after cardiac operation not uncommonly results in cardiac tamponade. Single chamber tamponade also might be expected, since in this setting the pericardium frequently contains firm blood clots localized to the area of active bleeding. However, this complication has received very little attention in the surgical literature. We are therefore providing documentation that isolated right atrial tamponade can occur as a complication of cardiac operation and that there exists a potential for misdiagnosis and hence incorrect treatment of this condition. Right atrial tamponade may be recognized by a combination of low cardiac output, low blood pressure, prominent neck veins, right atrial pressure in excess of pulmonary capillary wedge pressure and right ventricular end-diastolic pressure, and a poor response to plasma volume expansion. Findings on chest roentgenogram and gated wall motion scintigraphy may be highly suggestive. This review should serve to increase awareness of this complication and to provide some helpful diagnostic clues.

Bioprosthesis↗