Percutaneous balloon valvulotomy for calcific rheumatic mitral stenosis.
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Adult↗
Biomedical subjects
A Figueroa
Publications and source records attributed to A Figueroa.
Noninvasive determination of pulmonary arterial systolic pressure by continuous wave Doppler.
We evaluated the accuracy of continuous wave Doppler for estimating pulmonary arterial systolic pressure in patients with tricuspid regurgitation. Of 44 patients with a variety of cardiac disorders, 39 (89%) had Doppler-detected tricuspid regurgitation. Adequate spectral profiles of the flow signals were obtained in 34 of them (87%), representing 77% of the entire group. Continuous wave Doppler ultrasound was used to measure the maximum velocity of the regurgitant jet, and by applying the modified Bernoulli equation, the systolic pressure gradient between the right ventricle and the right atrium was calculated. Pulmonary arterial systolic pressure was estimated by adding the transtricuspid gradient to the mean right atrial pressure, and correlated well with catheterization values (r = 0.96). The correlation coefficient was not significantly modified if mean right atrial pressures were excluded in the calculations (r = 0.91). Continuous wave Doppler constitutes a sensitive method for the detection of tricuspid regurgitation. The method using the tricuspid gradient provides an accurate estimation of pulmonary arterial systolic pressure. Combined with other available methods (pulsed wave Doppler), this noninvasive technique can yield information comparable with that obtained at catheterization.
Adolescent↗
[Heart transplantation at the Marqués de Valdecilla Hospital, Santander].
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Adolescent↗
Protein conformational effects in hydrophobic interaction chromatography. Retention characterization and the role of mobile phase additives and stationary phase hydrophobicity.
We have studied the conformational behavior of alpha-lactalbumin (alpha-LACT) in hydrophobic interaction chromatography (HIC). Retention characterization in terms of Z (slope of plot of ln k' vs. ln phi B, where k' is the capacity factor and phi B is the volume fraction of mobile phase B) has been explored, and the relationship of Z to other slopes, such as S (slope of the plot of ln k' vs. phi B) has been derived. The reasons for the sensitivity of Z to conformational change are discussed. The enhanced broadening of alpha-LACT in a temperature transition region of conformational change has been studied by spectral analysis using on-line photodiode array detection. The influence of Ca2+ and Mg2+ addition to the mobile phase is further explored. Since alpha-LACT is a calcium binding protein, addition of this metal leads to stabilization, i.e. higher column temperatures are required for conformational change. On the other hand, addition of Mg2+ appears to destabilize the protein. We have explored the use of a more hydrophobic support, C2-(ethyl) ether phase, for the elution of alpha-LACT. In this case, two widely separated peaks are observed. By spectral analysis the first peak is shown to be native and the later eluted, broad second peak to be an unfolded mixture of species. As previously observed in reversed-phase liquid chromatography, the second peak grows at the expense of the first, as the column temperature is raised. The second peak also grows as the contact time of the protein with the surface increases. This behavior can be ascribed to the conformational change of alpha-LACT in the column, the late eluted species under the second peak binding significantly more strongly to the phase than the native peak. Reinjection of the late eluted fraction reveals that reformation of the native species takes place in solution within 30 min. As before, addition of Ca2+ reduces the extent of unfolding under any specific condition. These results add further to our understanding and ability to control conformational changes in high-performance liquid chromatography.
Animals↗
High-performance immobilized-metal affinity chromatography of proteins on iminodiacetic acid silica-based bonded phases.
High-performance separations of proteins, based on immobilized-metal affinity chromatography (HPIMAC), are described. The stationary phase consisted of iminodiacetic acid (IDA) chelate groups, bonded to small particle, wide pore silica gel by means of a polyether hydrophilic leash. After loading the column with metal, retention of proteins was achieved by protein-metal complexation at high concentrations of sodium sulfate. Elution was accomplished by addition of competitive complexing ligands, such as ammonia at constant pH, and/or by a decreasing pH gradient of a specially designed buffer system to maintain buffer capacity constant throughout the gradient. Selective separations, based on differences in the number of histidine residues present on the surface of the proteins, are described. The application of HPIMAC in the separation and purification of structurally similar proteins is presented. The potential application of IDA columns in three chromatographic modes (HPIMA, hydrophobic interaction, and cation exchange) is also described.
Ammonia↗
Comparison of Doppler-determined elevated pulmonary arterial pressure with pressure measured at cardiac catheterization.
This study assesses use of pulsed Doppler echocardiography to measure pulmonary artery (PA) pressure. PA flow at the right ventricular (RV) outflow tract was analyzed in 51 patients. Attention was focused on PA flow morphologic pattern, RV systolic intervals, time to peak flow and acceleration time index. Correlation was made with PA pressure and total pulmonary resistance. Three morphologic patterns of PA flow were found: type I indicates normal PA pressure (sensitivity 85%, specificity 100%) and types II and III indicate PA hypertension (sensitivity 100%, specificity 85%). The RV preejection/RV ejection ratio, time to peak flow and acceleration time index show a good correlation coefficient improved when a logarithmic function was applied. The best correlation was achieved with time to peak flow (r = -0.77 with PA pressure, r = -0.79 with total pulmonary resistance), and especially with acceleration time index (r = -0.84 with PA pressure, r = -0.87 with total pulmonary resistance). Analysis of pulmonary flow is a reliable new tool for evaluating PA pressure and is even better for evaluating total pulmonary resistance. Acceleration time index is the parameter that correlates best with these 2 variables.
Adolescent↗
Early clinical results with the Xenomedica porcine bioprosthesis.
All patients undergoing heart valve replacement with a glutaraldehyde-preserved Xenomedica xenograft from June 1983 through November 1983, were reviewed. This analysis included 75 patients: 37 having undergone aortic valve replacement, 23 mitral valve replacement, and 15 mitral and aortic valve replacement. Of 70 patients discharged from the hospital, there were 5 late deaths, which represents an incidence of 1.06% per patient-year. Twenty-six patients were recatheterized between 3 and 6 months postoperatively. The mean mitral valve orifice area was 1.57 +/- 0.37 cm2. The average mitral valve gradient was 9.8 +/- 2.9 mmHg. No differences in hemodynamic behavior were found between standard and composite mitral prostheses. The average aortic valve peak systolic gradient was 11 +/- 6 mmHg. Fourteen out of the 34 mitral (41%) and 5 out of 52 aortic (9.6%) prostheses have some degree of incompetence. We have discontinued the use of this cardiac bioprosthesis due to the frequent appearance of incompetence in mitral valves, and high transvalvular gradients in mitral prostheses.
Adult↗
Radiosensitization by derivatives of isoindole-4,7-dione.
New derivatives of isoindole -4,7-dione have been synthesized and their radiation sensitization and chemical behavior have been studied. One-electron reduction potentials have been determined by pulse radiolysis and found to be in the range of -0.45 to -0.36 V vs NHE . Radiosensitization effects were tested in vivo using soft tissue sarcoma transplanted in mice. All the isoindole -4,7-diones tested were found to exert considerable radiosensitization, approaching that of misonidazole tested under comparable conditions. The derivatives which contain a carbethoxy group on the pyrrolic ring were found to have more positive reduction potentials and to act as more efficient sensitizers. Further development of this class of radiosensitizers is underway.
Animals↗
Analysis of the amount of tricuspid valve anular dilatation required to produce functional tricuspid regurgitation.
To determine the critical anular dilatation required for functional tricuspid regurgitation (TR) and the role of systolic anular shortening in the severity of TR, 67 patients in whom right ventriculography had been performed were studied. These patients were classified into group I, control (n = 12), and the group II, patients with rheumatic valvular disease (n = 55). Group II patients were subclassified as follows: IIa, without TR (n = 19); IIb, with mild TR (n = 22); and IIc, with moderate to severe TR (n = 14). The angiographic maximal early systolic and minimal end-systolic diameters were measured. The shortening of the tricuspid anulus was expressed as percent reduction of the maximal diameter. The average maximal diameter (mm/m2) was: group I, 21 +/- 2; group IIa, 24 +/- 2; group IIb, 31 +/- 4; and group IIc, 37 +/- 4. The average minimal diameter (mm/m2) was: group I, 15 +/- 2; group IIa, 18 +/- 2; group IIb, 23 +/- 2; and group IIc, 31 +/- 3. The average percent shortening was: group I, 30 +/- 7%; group IIa, 25 +/- 7%; group IIb, 26 +/- 5%; and group IIc, 15 +/- 3%. The rheumatic patients had a larger maximal diameter than did those in the control group. Anular shortening was reduced only in the group with moderate to severe TR and preserved in the other groups, including those with mild TR. The critical diameter was determined to be between the maximal diameter in the rheumatic patients without TR and the minimal diameter in the patients with moderate to severe TR, or 27 mm/m2. Thus this easily measured parameter can determine the presence and significance of functional TR, adding objectivity to the angiographic diagnosis of TR.
Adolescent↗
Abortion in mice induced by intravenous injections of antibodies to type IV collagen or laminin.
Purified antibodies to laminin or Type IV collagen administered intravenously to pregnant mice were found to localize in the basement membranes of all maternal tissues as well as the parietal and visceral yolk sacs and trophoblast basement membranes but not in embryonic tissues. Antibodies to Type IV collagen induced a higher incidence of abortions, retroplacental hematomas and fetal deaths. When administered intraamniotically, both antiserums were embryotoxic. The functional consequences of the attachment of antibodies to these specific basement membrane antigens appear to be hemorrhage within the parietal and visceral yolk sacs and separation of fetal from maternal tissues. Complement activation appears to play an important role in the interruptions of pregnancy, because this was not observed in strains of mice lacking C5, the fifth component of complement, in mice depleted of C3 by administration of cobra venom factor, or in mice injected with the F(ab) fragments of antibody to Type IV collagen or laminin.
Abortion, Induced↗
Terminal transverse defects with orofacial malformations (TTV-OFM): case report with mandibular prognathism and submucous cleft palate.
Terminal transverse defects of varying severity, ranging from aplasia of phalanges and digits to hemimelia, have been reported in association with various orofacial malformation. Temtamy and McKusick (1978) introduced the term "terminal transverse defects with orofacial malformations (TTV-OFM)" as a formal genesis syndrome (etiologically undefined) to include the following clinical entities: (1) aglossia-adactylia syndrome; (2) ankyloglossum (superius) syndrome; (3) Hanhart syndrome; (4) ectrodactyly with OFM; and (5) Möbius syndrome with digital malformations (including the Charlie "M" syndrome). This report describes a patient whose phenotypic characteristics qualify for inclusion under this heading, but with facial features somewhat different from those previously reported in the literature including the presence of an eccentric submucous cleft of the hard palate and zona pellucida of the soft palate.
Abnormalities, Multiple↗
Right ventriculography as a valid method for the diagnosis of tricuspid insufficiency.
The value of right ventriculography in the diagnosis of tricuspid insufficiency (TI) is often questioned because of 1) the high incidence of premature ventricular contractions (PVCs) during injections and 2) interference of the catheter in the valve closure mechanism. In 168 patients a commercially available, not preshaped, balloon-tipped catheter was used for right ventriculography. To avoid the induction of PVCs, the catheter tip was placed in the middle third of the diafragmatic wall of the right ventricle, and the balloon was inflated, becoming trapped by the trabeculae. In this position the catheter's side holes should be located in the inflow chamber. To ensure this correct position, and therefore lack of ectopic beats during angiography, a saline test injection was performed previously in every case. With this technique the incidence of PVCs during ventriculography was only 7.7%. In all but one case, such beats were isolated. The 168 patients were divided into three groups according to their likelihood of experiencing tricuspid interference by the catheter: group 1 included 41 patients with a normal heart or with coronary artery disease. No one from this group had TI. Of group II, 28 patients with right ventricular pressure or volume overload or cardiomyopathy, only 2 had TI, both with a previous clinical diagnosis of regurgitation. Group III contained 99 patients with rheumatic heart disease. Thirty-five of them showed angiographic TI, and 24 of these had this diagnosis confirmed either clinically or at surgery. It is felt that this technique of right ventriculography, with its low incidence of PVCs and slight interference with tricuspid closure, is a valid method for the objective study of the tricuspid valve.
Adolescent↗
Coronary arteriography and atrial thrombosis in mitral valve disease.
The arteriographic findings of neovascularity and fistula formation from the coronary arteries to the left atrium have occasionally been reported in association with atrial thrombosis in patients with mitral valve disease. To establish the diagnostic value of these findings, the preoperative coronary angiograms of 507 patients who underwent open mitral valve surgery were reviewed. Atrial thrombosis was present in 76 patients (14.9 percent). In the 30 patients with angiographic neovascularity and fistula formation, the thrombi were always observed to arise from the circumflex coronary artery. None of these 30 patients had atherosclerotic coronary lesions. In 25 of these patients an atrial thrombus was found at operation. These coronary arteriographic findings, in this selected group of patients, had a predictive accuracy of 83.3 percent, a specificity of 98.8 percent and a sensitivity of 32.8 percent for the diagnosis of the presence of thrombus in the left atrium. No relation was found between these signs and the size and histologic age of the thrombi examined.
Adult↗
[Dilatation of coronary stenosis by percutaneous transluminal angioplasty].
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Angina Pectoris↗
[A new method of right ventriculography for diagnosing tricuspid valve insufficiency].
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Angiography↗
Induction of cleft lip in cultured rat embryos by localized administration of tunicamycin.
Whole-embryo culture techniques have advanced to the point where the study of normal and abnormal primary palate development in vitro is possible. The purpose of this study was to ascertain whether localized administration of tunicamycin (TM) an inhibitor of protein glycosylation, into the region of the developing primary palate would induce cleft lip in culture. Rat embryos were explanted on late day 11 of gestation and cultured with open yolk sacs for 40 h. TM was administered by implanting a sterile eyelash soaked in TM into the nasal placode region. The contralateral placode was used as the control by implanting an eyelash lacking TM. Under these conditions, TM-treated placodes were found to develop cleft lip in 14 out of 15 embryos compared to 0 for the controls. These experiments demonstrate that localized administration of TM results in cleft lip formation in whole embryo culture. The technique of localized administration of drugs and teratogens in whole embryo culture should prove useful for similar studies on embryonic development.
Animals↗
Detection of epidermal growth factor-urogastrone and its receptor during fetal mouse development.
Using both a radioimmunoassay and a radioreceptor assay, we have estimated the content of mouse epidermal growth factor-urogastrone (EGF-URO) in fetal mice at 11(1/2) to 17(1/2) days of gestation. Concurrently, the amount of specific EGF-URO receptor binding was determined in crude membrane fractions from the embryos. EGF-URO receptor binding is readily detected in membranes from the youngest embryos (day 11(1/2)) and rises steadily up to parturition (18 days); the rise is more marked in embryo membranes derived from a potential target tissue, such as the maxilla and secondary palate. In the embryonic extracts, EGF-URO proved to be labile, requiring the presence of soybean trypsin inhibitor and sodium azide to stabilize the recovery of added EGF-URO in test samples. Even with added stabilizing agents, immunoreactive EGF-URO was barely detectable before day 14(1/2) (less than 20 fmol per embryo), whereas a substantial increase was observed from day 15(1/2) to 17(1/2) (from 70 to 200 fmol per embryo). In contrast, the radioreceptor assay detected appreciable amounts of an EGF-URO-like substance at 11(1/2) days (50 fmol per embryo); the values estimated by radioreceptor assay (about 10-fold higher than by radioimmunoassay) also increase markedly between days 15(1/2) and 17(1/2) (on average from 500 to 3000 fmol per embryo). We conclude that during fetal mouse development there is an increase both in the receptors for EGF-URO and in a substance (presumably a fetal growth factor) that can occupy the receptor. The differences between the radioreceptor and radioimmunoassay estimates for the EGF-URO content suggest that the fetal form of mouse EGF-URO differs from the adult molecule.
Animals↗
Hemodynamic factors that affect calculated orifice areas in the mitral hancock xenograft valve.
From June 1974 to December 1978, 714 Hancock valves have been placed in 605 patients. One hundred seventy-five patients with a mitral xenograft have been restudied. The results were questionable due to the wide scatter and disparity between the calculated and the theoretical orifice of each valve size. To elucidate these differences, the hemodynamic data of 40 isolated, normal functioning mitral Hancock valves were reviewed. Early, middle and late diastolic mitral valve gradients were measured by planimetry and their corresponding flows were estimated by angiography. The paired data were fitted to exponential functions and specific lines for each Hancock valve size were obtained. By superimposing Gorlin's pressure and flow curves on these lines, the instantaneous effective orifice for each Hancock valve can be determined. We concluded that 1) the Hancock valve effective orifice is flow related and always lower than its theoretical opening; 2) normal function frequently cannot be firmly established by the mean effective area; and 3) the nomogram described may help in determining the time-related variations of a particular valve.
Adult↗