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A Sequeira

Publications and source records attributed to A Sequeira.

17 recordsLinked to original sources
PubMed2000

Genetic diversity among isolates of Trichinella spiralis from the Province of Buenos Aires, Argentina.

Random Amplified Polymorphic DNAs, (RAPDs) are used to study the occurrence of Trichinella britovi and T5 among domestic animals in the Province of Buenos Aires, Argentina and to assess the genetic diversity among isolates of T. spiralisfrom this area in a number of infected hosts. All the local isolates proved to be T. spiralis. Six of the eight primers used indicate that the Buenos Aires isolates are distinct from each other as they produce a considerable number of polymorphic bands. Our overall estimates are relatively higher than other intraspecific distances previously estimated within species of this genus and among T. spiralis isolates. Such high degrees of variability observed among local isolates and between isolates from Buenos Aires and Spain should be taken into account when defining isolates within this species, and considering differences in the epidemiology of T. spiralis.

Animals↗
PubMed1999

Apparent dopamine D1 and D2 receptors in the weaver mutant mouse: receptor binding and coupling to adenylyl cyclase.

Weaver mutant mice have a selective degeneration of the nigrostriatal dopamine pathway arising between 7-21 days after birth. The goal of this study was to investigate the effects of this mutation on different parameters of the nigrostriatal and mesolimbic dopamine system: apparent D1 and D2 receptor binding sites as well as their signal transduction pathway. Using quantitative autoradiography of ligands for dopamine D1, D2 receptors and the dopamine uptake site, we found a significant loss in apparent D1 receptor binding sites throughout the neostriatum, significant increase of apparent D2 receptor binding in the dorsal aspect of the neostriatum, and almost complete loss of DA uptake sites in these regions of the weaver mouse. In contrast to the neostriatum, the density of dopamine receptors and uptake sites in the nucleus accumbens of the weaver mouse did not differ from controls. Despite alterations in the binding of apparent D1 and D2 receptors, there was no significant difference in either basal, DA stimulated or GTPgammaS stimulated cAMP production. These findings suggest the down-regulation of apparent D1 receptor binding sites reported in this model, probably does not reflect an important physiological mechanism through which these animals compensate for loss of dopamine innervation.

Adenylyl Cyclases↗
PubMed1998

[The influence of therapy (sympathomimetic amines versus vasodilators) in the indexes of ejection fraction derived from an analysis of Doppler aortic flow].

PURPOSE: To assess the influence of inotropic IV therapy--dobutamine and/or dopamine--versus vasodilator therapy--nitroprusside, captopril or hydralazine--in aortic flow ejection phase indexes obtained by pulsed Doppler echocardiography. METHODS: In 17 patients admitted to the ICU (11 males, 62 +/- 14 years, 9 with ischemic cardiomyopathy and 8 with dilated cardiomyopathy, all in sinus rhythm), with congestive heart failure, and submitted to tailored therapy, 53 serial pulsed Doppler and hemodynamic evaluations were made as the therapy changed the hemodynamic and clinical status. Considering serial consecutive evaluations, a hemodynamic improvement was obtained only with inotropics in 13 (group A), and with vasodilators in only 15 (group B). The following ejection phase indexes were calculated from Doppler registers: average acceleration (AvAc) and ejection force (EFor), calculated according to the formula: Efor = 1.06 x Aortic Orifice Area x AvAc x Acceleration Velocity Time Integral. RESULTS: Arterial blood pressure increased in gr A (76.2 +/- 14.1 to 81.4 +/- 14.8 mm Hg, p < 0.05) and decreased in gr B (85.1 +/- 12.6 to 76.2 +/- 9.7 mm Hg (p < 0.05). In both groups there was a significant (p < 0.05) increase in cardiac output (CO)-from 3.9 +/- 1.1 to 4.9 +/- 1.4 L/min in group A, and from 3.9 +/- 1.2 to 4.4 +/- 1.2 L/min in group B. CO increased 18.7% in group A and 13.8% in group B (NS). There was a decrease in pulmonary capillary wedge pressure (PCWP) from 19.5 +/- 6.0 to 15.1 +/- 5.8 mm Hg in group A (p < 0.05), and from (16.9 +/- 5.7 to 12.1 +/- 4.6 mm Hg in group B (p < 0.05). PCWP decreased 19.7% in group A and 27.8% in group B (NS). Systemic vascular resistance (SVR) changed from 18.2 +/- 7.0 to 16.2 +/- 7.1 Wood U in group A (p < 0.05), and from 22.3 +/- 9.3 to 17.7 +/- 5.7 Wood U in group B (p < 0.05). In group A, AvAc increased-from 1347 +/- 611 cm.s-2 (p < 0.05), as did Efor-from 15.4 +/- 10.7 to 20.2 +/- 11.0 g.cm,s-2 (p < 0.05), whereas in group B there was no significant change in either AvAc-from 1337 +/- 284 to 1277 +/- 256 cm.s-2, or Efor-from 22.7 +/- 17.0 to 23.8 +/- 15.0 g.cm.s-2. CONCLUSIONS: Vasodilator therapy, although inducing hemodynamic changes similar to inotropics, does not alter the ejection phase indexes. Therefore, AvAc and Efor, in spite of being calculated from the aortic flow, are independent of the changes in PCWP and SVR and seem to reflect changes in inotropism in the clinical setting.

Captopril↗
PubMed1995

[The QTc interval and its dispersion in hypertrophic myocardiopathy--its relation to complex ventricular arrhythmias and the effect of anti-arrhythmia agents].

UNLABELLED: The aim of the present study was to evaluate, in patients with hypertrophic cardiomyopathy (HCM): 1. The relation of rate corrected QT interval (QTc) and of QTc interlead variability (QTc dispersion) to complex ventricular arrhythmias (CVA); 2. The effects of amiodarone (Am), beta-blockers (beta B) and calcium antagonists (CA) on QTc and on QTc dispersion. Surface 12 leads ECG was analysed in 55 patients with HCM (39 +/- 12 years, 32 males). All patients were in sinus rhythm, without bundle branch block. Maximum (max), minimum (min) and mean QTc values were considered. QTc dispersion was calculated as: a) max QTc - min QTc (max-min); b) dispersion index (DI) = standard deviation of QTc/mean QTcx100. Patients groups were defined accordingly to: 1--the absence (group A1-35 patients) or the presence (group A2-20 patients) of CVA on 24 hours Holter monitoring; II--absence of cardioactive medication (group B1-20 patients) versus monotherapy with Am (group B3-10 patients), or beta B (group B4-15 patients), or CA (group B5-10 patients). Age, gender, type of HCM (asymmetric versus concentric) and echocardiographic fractional shortening were not different in the studied groups. RESULTS: [table: see text] CONCLUSIONS: 1. Maximum QTc interlead QTc dispersion are increased in patients with HCM that show CVA on Holter monitoring; 2. Amiodarone prolongs QTc but reduces QTc dispersion, while beta-blockers and calcium antagonists do not significantly change neither the duration nor the dispersion of ventricular repolarization.

Adrenergic beta-Antagonists↗
PubMed1992

Molecular characterization of the variable regions of a mouse polyreactive IgG2b antibody with rheumatoid factor activity.

The complete nucleotide sequences of heavy and light chains of a mouse polyreactive IgG2b antibody were determined. This antibody, obtained after primary immunization of BALB/c mice with human lymphoblastoid cells, possess anti-HLA-DR and anti-rheumatoid factor activities and reacts with various self and nonself antigens. The VL and VH segments were found to belong to the VK8 and VH7183 families, respectively. The VH segment shared a high percentage of sequence similarity (95%) with previously described germline genes. The VK segment had 98.9% of sequence similarity with a consensus sequence VK8 of antibodies with anti-phosphorylcholine activity. Furthermore, the framework regions 2 and 3 of the VL segment were very similar to the framework regions 2 and 3 of other antibodies known to possess rheumatoid factor activity. We postulate that during immunization, the presence of HLA-DR antigens selects precursors having configurations similar to that of the germline, and induces some somatic mutations that do not significantly affect antibody polyreactivity.

Amino Acid Sequence↗
PubMed1992

Characterization of a murine immunoglobulin VH gene segment in subgroup III: a new member of the 7183 gene family.

A new gene for the variable region of the immunoglobulin heavy chain (VH gene) has been isolated from BALB/c adult liver DNA using a cDNA plasmid probe containing a mouse VH sequence. The complete nucleotide sequence of this germline gene (VH10-19), shows that it belongs to the 7183 gene family. The VH gene appears to contain an intervening 104-base-long sequence and displays the same recombination signal sequences that those observed in the germline 81X. The presence of an internal heptamer at the 3' end of the VH10-19 coding region let an alternative recombination event that could increase the representation of this gene in the immature repertoire.

Amino Acid Sequence↗
PubMed1991

Penetrating cardiac injuries.

One hundred nine penetrating cardiac injuries were reviewed: 49 gunshot wounds and 60 stab wounds. They were classified into four groups: group 1 (lifeless), 38; group 2 (agonal), 16; group 3 (shock), 33; and group 4 (stable), 22. Thirty-six patients in group 1 (94%) and 8 of 16 patients in group 2 (50%) underwent emergency room thoracotomy; 24 of 33 in group 3 (73%) and 20 of 22 (90%) underwent thoracotomy in the operating room. Twenty-one (38%) of 55 patients undergoing emergency room thoracotomy survived, whereas 47 (87%) of 54 patients undergoing operating room thoracotomy survived. Survival was 12 of 38 (31%) in group 1, 11 of 16 (69%) in group 2, 26 of 33 (79%) in group 3, and 18 of 22 (82%) in group 4 with an overall survival of 67 of 109 (61%). Gunshot wounds of the heart portend a worse prognosis than stab wounds. Survival of gunshot wounds was 20 of 49 (40%) compared with 47 survivors of 60 stab wounds (78%). Aggressive treatment, including emergency room thoracotomy, is justified for lifeless and deteriorating cardiac injury victims.

Adolescent↗
PubMed1990

Esophageal perforation: a therapeutic challenge.

The records of 64 patients with esophageal perforation treated since 1958 were reviewed. There were 19 cervical perforations, 44 thoracic perforations, and one abdominal perforation. Thirty-one perforations (48%) were due to injury from intraluminal causes. Twenty (31%) resulted from extraluminal causes: penetrating wounds, 11; blunt trauma, 3; and paraesophageal operations, 6. Eleven (17%) were spontaneous perforations, and two (3%) were caused by perforation of an esophageal malignancy. Ten (91%) of 11 patients with cervical perforations treated less than 24 hours after injury survived compared with 6 (75%) of 8 patients treated more than 24 hours after injury; hence 16 (84%) of the 19 patients in the cervical group survived. In the thoracic group, 19 patients were treated within 24 hours with 16 survivors (84%) compared with 25 patients treated beyond 24 hours with 12 survivors (48%); hence 28 (64%) of the 44 patients in the thoracic group survived. The patient with an abdominal perforation survived. Thirty patients underwent primary suture closure of the perforation, and 25 (83%) lived. Seventeen patients had drainage, and 10 (59%) lived. Total esophagectomy was performed in 9 patients, 7 (78%) of whom survived. Exclusion-diversion procedures were performed in 5 patients, and 1 (20%) survived.

Adult↗
PubMed1989

Postoperative conduction disturbances: a comparison of blood and crystalloid cardioplegia.

Conduction system disturbances after cardioplegia are well described. Our four-man group changed in mid-1987 from standard crystalloid cardioplegia (35 mEq/L of KCl) to blood cardioplegia (4 parts blood to 1 part cardioplegia) (18 mEq/L of KCl) based on experimental and clinical evidence that blood cardioplegia provides better myocardial protection. Shortly thereafter, we anecdotally noted increased conduction abnormalities. This prompted us to compare serially all patients undergoing coronary artery bypass grafting during 1987 for perioperative and late conduction system disturbances after either crystalloid or blood cardioplegia. Surgeons and techniques including topical cooling did not differ. Forty-one (23%) of 179 patients with crystalloid cardioplegia had conduction disturbances versus 141 (49%) of 289 patients with blood cardioplegia (p less than 0.001). Perioperative complete heart block requiring atrioventricular sequential pacing occurred in 20 patients with crystalloid cardioplegia versus 67 patients with blood cardioplegia (p less than 0.002), and atrioventricular block requiring permanent pacing was present in 4 and 12 patients (p less than 0.001), respectively. Left bundle-branch block was found in 8 patients given crystalloid cardioplegia and 28 patients with blood cardioplegia (p less than 0.05); right bundle-branch block, 12 and 68 patients (p less than 0.001); left anterior hemiblock, 8 and 37 patients (p less than 0.001); and interventricular conduction delay, 15 and 53 patients (p less than 0.005), respectively. Bifascicular block occurred in 4 patients receiving crystalloid cardioplegia versus 23 receiving blood cardioplegia (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1987

Use of a zipper in cardiac surgical operations.

A simplified technique to gain repeated access to the median sternotomy incision is presented. The technique involves the use of a sterile polyester zipper attached to the skin edge. The sternum remains open. Unzipping the zipper allows for repeated relief of cardiac tamponade and viewing of cardiac action. Other advantages include prevention of cardiac compression or kinking of assist device cannulas from sternal closure, ease in changing of dressings, and quick removal of ventricular assist devices without reopening the sternum.

Bandages↗
PubMed1984

Management of penetrating cardiac injuries: the role of emergency room thoracotomy.

Sixty-four consecutive patients with penetrating cardiac injuries were treated between January, 1977, and January, 1983, at the University of Maryland Hospital. Twenty-eight patients had major associated injuries of other organs. The patients were divided into groups according to their clinical status on arrival. An aggressive approach was utilized including early emergency room (ER) thoracotomy for "lifeless" or deteriorating patients. Three patients required immediate cardiopulmonary bypass for repair of their injuries. Twenty-one (57%) of the 37 patients undergoing ER thoracotomy survived; most of the deaths occurred in patients arriving "lifeless" from gunshot wounds. Twenty-four (89%) of the 27 patients who were in stable enough condition to undergo initial repair in the operating room (OR) survived. Overall survival was 45 patients (70%). Though superficial wound infections developed in 18 patients, there were no deep or systemic infections. None of the survivors sustained severe neurological sequelae. Five patients underwent late reoperations for closure of a ventricular septal defect (2), mitral valve replacement (1), and pericardiectomy (2) with no deaths. Though repair of penetrating cardiac injuries should preferably be carried out in the OR, immediate thoracotomy for "lifeless" or deteriorating patients can be performed in the ER with a low incidence of direct surgical complications and with high patient survival.

Adolescent↗