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Biomedical subjects

L Kidd

Publications and source records attributed to L Kidd.

At least 37 records · Page 2Linked to original sources
PubMed1993

Second natural history study of congenital heart defects. Results of treatment of patients with ventricular septal defects.

BACKGROUND: From 1958 to 1969, 1,280 patients (mostly children) with ventricular septal defects (VSDs) were admitted to the First Natural History Study of Congenital Heart Defects (NHS-1) after cardiac catheterization. Most with small defects and Eisenmenger's syndrome were managed medically; most with large VSDs were managed surgically. Of those with moderate-size defects, some were managed medically, and some were managed surgically. Most had a second catheterization at the conclusion of NHS-1. More than 15 years have elapsed since NHS-1, and most of the cohort are adults. This report (Second Natural History Study) addresses the long-term results of medical and surgical management. METHODS AND RESULTS: Of an original cohort of 1,280 patients, 1,099 were alive at completion of NHS-1. New data were obtained on 976 (76.3%) of the original cohort. Probability of 25-year survival was 87%, and admission severity was the best predictor of survival. Of the 860 patients managed medically during NHS-1, 245 subsequently required surgical closure of the VSD. Only 5.5% of patients who had surgical closure required a second operation. On follow-up, there was a higher-than-normal prevalence of serious arrhythmias. Bacterial endocarditis occurred rarely. Of patients with small VSDs, 94.1% were in New York Heart Association functional class I. With the exception of those with Eisenmenger's syndrome, most patients had a final clinical status that was excellent or good. CONCLUSIONS: The majority of patients fared well. However, there was a higher-than-normal prevalence of serious arrhythmia and sudden death, including those with small VSDs.

Adolescent↗
PubMed1993

Second natural history study of congenital heart defects. Materials and methods.

Results of the location and recruitment efforts and comparisons of responses from patients who cooperated at different levels in the Second Natural History Study of Congenital Heart Defects are included because they influenced the choice of analytic methods and are essential to the generalizability of the results to the entire study cohort. Included are examination and data collection protocols (e.g., protocol definitions, test procedures, and data editing), statistical methods (e.g., box plots, survival curves, multivariable models, and rate adjustment), participation results (e.g., proportional odds analysis, mortality, location, recruitment, and full participants, including comparison of questionnaire responses and comparison of questionnaire response and physician history), and a discussion.

Data Collection↗
PubMed1993

Second natural history study of congenital heart defects. Quality of life of patients with aortic stenosis, pulmonary stenosis, or ventricular septal defect.

BACKGROUND: Quality of life of patients with congenital heart defects is an important aspect of the assessment of outcome of medical and surgical treatment. METHODS AND RESULTS: All participants in the Second Natural History Study of Congenital Heart Defects who completed the study questionnaire were included in this analysis. The questionnaire completed by the patients included inquiries relative to medical history, marital and family life, self-perception of well-being, insurability, and employability. The following general observations were apparent. The study cohort reported a self-perception of health status that was similar to that of the general population. Second, 35-40% of patients had not had a cardiac evaluation within the previous 10 years. Third, 16% of the patients had no health insurance, and 35.7% of the patients had no life insurance. For the patients with pulmonary stenosis and ventricular septal defect, the percent who were married was less than that of the corresponding national age- and sex-specific population. For patients with aortic stenosis, the percent married was greater than that of the general population for some age groups. The proportion of divorced or separated individuals was similar to that of the general population. For all three defects, the level of educational attainment exceeded the national average. Last, unemployment rates were similar to national averages except for women with aortic stenosis, who had a significantly higher unemployment rate than did age- and sex-matched controls. CONCLUSIONS: Patients initially identified with aortic stenosis, pulmonary stenosis, or ventricular septal defect in 1959-1973 have a quality of life in the mid-1980s similar to that of the general US population.

Adult↗
PubMed1993

Arrhythmias in patients with valvar aortic stenosis, valvar pulmonary stenosis, and ventricular septal defect. Results of 24-hour ECG monitoring.

BACKGROUND: Arrhythmias are a significant source of morbidity and mortality in patients with congenital heart defects. METHODS AND RESULTS: As part of the Second Natural History Study of Congenital Heart Defects (NHS-2), 24-hour ambulatory ECG monitoring was performed for full participants in the study. At least 15.5 hours of monitoring was required for inclusion in the analysis. This was achieved for 755 (90.6%) of the patients. Multiform premature ventricular contractions, ventricular couplets, and ventricular tachycardia were considered "serious arrhythmias." For patients with aortic stenosis, the presence of "serious arrhythmias" was associated with higher left ventricular end-diastolic pressure, presence of aortic regurgitation, male sex, and presence of prior aortic valve replacement. For patients with pulmonary stenosis, only older age on admission to NHS-1 was significantly associated with "serious arrhythmias." For patients with ventricular septal defect, the variables associated with "serious arrhythmias" were different for medically and surgically managed patients. For medically managed patients, higher mean pulmonary artery pressure on admission to NHS-1 and older age on admission to NHS-2 were associated with the presence of serious arrhythmias. For surgically managed patients, higher New York Heart Association functional class and cardiomegaly were associated with serious arrhythmias. CONCLUSIONS: The prevalence of arrhythmias (especially ventricular arrhythmias) was higher for patients with aortic stenosis, pulmonary stenosis, or ventricular septal defect than for an historical control population. "Serious arrhythmias" were most frequently noted in patients with aortic stenosis who also had a higher incidence of sudden death. The prevalence of "serious arrhythmias" was second highest for patients with ventricular septal defect who had the second highest incidence of sudden death.

Adult↗
PubMed1992

Clinical pharmacokinetics of 3'-azido-3'-deoxythymidine (zidovudine) and catabolites with formation of a toxic catabolite, 3'-amino-3'-deoxythymidine.

This study investigated pharmacokinetics and metabolism of 3'-azido-3'-deoxythymidine (zidovudine) in patients after a 1-hour intravenous infusion of 2.5 mg/kg zidovudine with a radiolabeled tracer amount of [5-3H]-zidovudine. In addition to unchanged drug and its 5'-O-glucuronide (zidovudine glucuronide), two novel catabolites of zidovudine were detected as 3'-amino-3'-deoxythymidine (AMT), and its 5'-O-glucuronide (GAMT). The AMT apparent plasma elimination half-life (2.70 +/- 0.7 hours) was longer than that of zidovudine (1.20 +/- 0.30 hours) and zidovudine glucuronide (1.60 +/- 0.5 hours). The zidovudine/AMT plasma peak concentration and area under the concentration-time curve ratios were approximately 8 and 5, respectively. Urinary recovery of radioactivity was essentially complete within 24 hours. AMT glucuronide was not detected in urine or plasma, and only low levels of this catabolite were detected in bile. In contrast, AMT was not detected in bile. The substantial levels of AMT in the plasma of patients after zidovudine administration suggests that this catabolite may affect the pharmacodynamic properties of zidovudine in relation to its activity against human immunodeficiency virus replication and cytotoxicity to host cells.

Aged↗
PubMed1992

Five cases of gastrocnemius tendinitis in the horse.

The normal gastrocnemius tendon may contain some muscular tissue proximally. This results in a patchy echogenicity ultrasonographically where it lies caudal or lateral to the superficial digital flexor tendon (SDFT). When it has assumed a position dorsal (cranial) to the SDFT the gastrocnemius tendon has a more uniform echogenicity and its margins are well defined. Five horses had lameness associated with lesions identified ultrasonographically in the gastrocnemius tendon in the latter region. Lameness ranged from mild to severe and was characterised by reduced hock flexion, lowered arc of foot flight, shortened length of the cranial phase of the stride and in some horses a reduced duration of weight bearing during the caudal phase of the stride. Lameness was variably accentuated by flexion of the proximal or distal limb joints of the lame limb. Perineural analgesia of the tibial and fibular nerves or the tibial nerve alone substantially improved the lameness. All horses remained lame 2-3 months after initial examination, with minimal change in the ultrasonographic appearance of the lesion(s).

Animals↗
PubMed1991

Determinants of outcome in hospitalized infants with congenital heart disease.

To identify determinants of adverse outcome in this era of early, definitive treatment, retrospective data were analyzed for 1988 on infants aged less than 1 year with congenital cardiac disease hospitalized at The Johns Hopkins Hospital. In this cohort of 108 infants, 34% (37 of 108) had complex cardiac disease, 33% (36 of 108) had major extracardiac anomalies, 88 patients (81%) underwent 116 surgical procedures, 37% (40 of 108) were hospitalized for greater than 28 days and 29% (31 of 108) died during the first year. Univariate analysis showed that complex disease (i.e., severe ventricular hypoplasia, ventricular septal malalignment or outflow atresia), extracardiac anomalies, early initial presentation, and prolonged stay in the intensive care unit were significantly associated with infant death, whereas surgery was associated with a significantly increased rate of survival. The findings for complex disease and surgery persisted in multiple logistic regression analysis. It is concluded that outcome in most infants with congenital cardiac defects is now extremely favorable, and that major research and preventive efforts should focus on complex congenital cardiac defects.

Female↗
PubMed1991

The A9 antigen associated with aggressive human squamous carcinoma is structurally and functionally similar to the newly defined integrin alpha 6 beta 4.

We previously reported that altered expression of the A9 antigen (defined by monoclonal antibody UM-A9) is a predictive marker of early recurrence and progression of squamous cell carcinoma (SCC). In normal squamous cells A9 expression is limited to the site of contact with the basement membrane in vivo and the culture surface in vitro, whereas aggressive SCCs exhibit loss of polarity and increased intensity of A9 expression. The potential relationship of the A9 antigen to structures known to be involved in cell adhesion was analyzed by immunobiochemical and cell adhesion assays. UM-A9 precipitates a complex of protein chains reminiscent of the alpha and beta heterodimer glycoproteins that characterize the integrin family of extracellular matrix receptors. Proteins were isolated from A9-positive cells using UM-A9 and well-defined antibodies specific for integrin alpha and beta chains. UM-A9, anti-alpha 6, and anti-beta 4 monoclonal antibodies (mAbs) all precipitated proteins with comparable electrophoretic mobilities. Furthermore, UM-A9 mAb precleared the SCC alpha 6 beta 4 integrin complex isolated with anti-alpha 6 or anti-beta 4 mAbs but not that isolated by anti-beta 1 mAb. The isoelectric points of the A9 complex chains were consistent with those reported for alpha 6 and beta 4. Three of the polypeptide chains (140, 175, and 205 kDa) precipitated by UM-A9 showed peptide homology to one another and to the beta 4 chain precipitated by mAb 439-9B. The A9/alpha 6 subunit is composed of 125- and 30-kDa chains and was distinguished from beta 4 and beta 1 chains by its peptide map and isoelectric point. UM-A9 binds to an epitope common to the beta 4 subunits since in pulse-chase analysis the beta 4 species are precipitated at an early time point, whereas detection of alpha-subunit synthesis is detected during assembly of the mature complex. Immunoprecipitation and preclearing experiments demonstrated that in SCC the alpha 6 subunit is associated primarily with the beta 4 species and not with the 130-kDa beta 1 subunit. In cell adhesion assays on extracellular matrix proteins, the alpha 6-specific GoH3 mAb inhibited binding of SCC to laminin, suggesting that alpha 6 beta 4 may function as a laminin receptor in SCC. These data and our prior observations showing an association between altered A9 expression and early recurrence in SCC provide the first evidence that altered expression of alpha 6 beta 4 integrin is associated with the clinical behavior of human squamous cell carcinomas.

Antigens, Neoplasm↗
PubMed1991

Cardiac care for infants. Determinants of hospital charges for acute care.

We analyzed hospital use and inpatient charges retrospectively for infants hospitalized at a tertiary referral center in the first year of life for cardiac disease. For 93 infants hospitalized between August 1987 and June 1989, there were 1.8 admissions per patient, with a median stay of 14 days; 24.7% required more than 28 days of acute inpatient care. Total hospital charges (excluding professional fees) in the first year of life were $3,417,612, which represents $36,749 per infant and $35,386 per survivor. Reimbursement totaled 93.2% of charges. Multivariate analysis revealed that complex disease, surgery, and length of stay in the intensive care unit were significantly associated with increased charges, while extracardiac anomalies, birth weight, outcome, and type of insurance were not. The economic benefits of averting infant death outweigh the associated costs by as much as 5.4 to 1. We conclude that current treatment of most infants with cardiac disease is both effective and economically beneficial.

Baltimore↗
PubMed1991

Lung function and pulmonary regurgitation limit exercise capacity in postoperative tetralogy of Fallot.

Fifty-five patients with repair of tetralogy of Fallot were evaluated with treadmill exercise, pulmonary function testing and rest two-dimensional and Doppler echocardiography to determine the relation among cardiopulmonary function, exercise capacity and ventricular arrhythmias. The mean age at repair was 8.1 +/- 2.1 years; age at the time of study ranged from 15 to 37 years (mean follow-up time after repair 18 +/- 5 years). Exercise duration was 92 +/- 17% of predicted. Maximal heart rate was 94 +/- 7% of predicted. No exercise test was stopped because of an arrhythmia. Thirty patients had oxygen consumption and ventilation measured during their final minute of exercise. Peak oxygen consumption was 31 +/- 8 ml/kg per min (86 +/- 18% of predicted). Twenty-five patients (45%) had low vital capacity at rest (less than 80% of predicted). Pulmonary regurgitation was identified in 42 (75%) of the patients and judged to be moderate in 10 (18%). Mild tricuspid valve regurgitation was identified in 64%. Doppler estimated right ventricular outflow gradient was greater than 15 mm Hg in 15% of the patients (mean gradient 24 mm Hg [range 16 to 56]). Age at repair, duration of follow-up and type of repair did not correlate with echocardiographic variables, ventilatory data, exercise performance or arrhythmias. Moderate pulmonary regurgitation was associated with increased right ventricular diastolic area and both were inversely related to exercise duration and vital capacity. Decreased breathing reserve during maximal exercise was associated with moderate pulmonary regurgitation and decreased vital capacity. The results indicate that exercise capacity in these patients is in general good; however, right ventricular volume loading and ventilatory dysfunction may produce exercise limitation.

Adolescent↗
PubMed1990

Calcium regulation of antigen expression on normal and malignant human squamous cells in vitro.

In vitro, normal keratinocytes exhibit undifferentiated morphologic features and proliferate for multiple passages in low-calcium medium (less than or equal to 0.3 mmol/L) whereas, in high-calcium medium (greater than or equal to 1.0 mmol/L), these cells assume differentiation characteristics, begin to stratify, and eventually cease proliferating. In contrast, malignant keratinocytes grow well in high-calcium medium. Expression of pemphigus vulgaris antigen, a squamous cell marker, is altered on cultured normal keratinocytes by calcium. In this study we compared the effects of calcium levels on expression of cell surface antigens by UM-SCC-38, a human squamous carcinoma cell line, and normal keratinocytes cultured from newborn foreskin. Pemphigus, pemphigoid, beta 2-microglobulin antigens, as well as the epidermal growth factor receptor and the A9 germinal epithelial cell basement membrane squamous carcinoma antigen were examined. Pemphigus antigen was strongly expressed on normal and malignant cells in high-calcium but not low-calcium medium. Calcium concentration did not affect the expression of any of the other antigens tested. Thus, although calcium induces differentiation and eventual loss of proliferative capacity in normal but not malignant keratinocytes in vitro, we were unable to demonstrate differences in pemphigus vulgaris antigen expression that might be linked to the growth inhibitory effects induced by high calcium levels in nontransformed epithelial cells in culture.

Antigens, Surface↗
PubMed1988

Handgrip strength after the Blalock-Taussig shunt: 14 to 34 year follow-up.

To determine the long-term functional impact of the Blalock-Taussig (BT) shunt, we studied handgrip strength in 56 patients (10-28 years) following total repair of tetralogy of Fallot. Of the 56, 16 (29%) had a previous right BT shunt, 5 of 56 (9%) had a previous left BT shunt, and the remaining 35 patients either had a Potts shunt or primary total repair. The mean age at the time of right BT was 2.8 +/- 1.6 (SD) years, left BT 1.7 +/- 1.2 years, and total repair for all patients was 7.1 +/- 2.2 years. Mean age at the time of study was 26 +/- 9 years. Right-and left-handgrip strength were measured with a Jamar dynamometer, averaging the results of grip position 2, 3, and 4 to accommodate variation in hand size. Since absolute values of hand strength were strongly associated with sex (p = 0.006) and body surface area (p = 0.016), we calculated the ratio of right-hand to left-handgrip strength (RL ratio). The RL ratios were: 0.98 +/- 0.13 (right BT), 1.21 +/- 0.11 (left BT), and 1.13 +/- 0.16 (no BT): (p = 0.004 right BT vs. no BT, p = 0.07 left BT vs. no BT, Wilcoxon rank sum test). Thus, although frequently clinically inapparent, handgrip strength tested many years post-BT shunt is reduced on the side of the shunt.

Adult↗
PubMed1988

Long-term valvular function after total repair of tetralogy of Fallot. Relation to ventricular arrhythmias.

Patients with total repair of tetralogy of Fallot may have residual valvular dysfunction, the long-term effect of which is poorly defined. We prospectively studied 59 patients for 18 +/- 5 (mean +/- SD) years postoperatively by Doppler echocardiography and by 24-hour electrocardiographic monitoring. Right ventricular outflow gradients were estimated from the peak continuous-wave Doppler pulmonary artery velocity. The severity of valvular regurgitation was determined by mapping the proximal chamber by pulsed Doppler methods. Right ventricular diastolic cavity area was measured by planimetry of the apical image. The right ventricular outflow tract gradient had a mean value of 9.4 +/- 9.0 mm Hg (range, 0-58 mm Hg; median, 6.6 mm Hg). Pulmonary regurgitation was present in 78% of patients, with 59% of patients graded as mild and 19% as moderate. Tricuspid regurgitation was found in 65% of patients, with 56% of patients graded as mild, 7% as moderate, and 2% as severe. The severity of pulmonary regurgitation correlated with right ventricular cavity area (p less than 0.05). The severity of tricuspid regurgitation was not related to pulmonary stenosis or to the severity of pulmonary regurgitation. Aortic regurgitation is unusual (n = 11) and correlates with aortic root size. The frequency and type of ventricular arrhythmia were not related to the severity of pulmonary stenosis; however, ventricular bigeminy and couplets were related to the severity of pulmonary regurgitation (p less than 0.025). The majority of patients with total repair of tetralogy of Fallot have remarkably good long-term valvular function. For the minority with moderate or severe valvular dysfunction, pulmonary regurgitation is the best marker for ventricular arrhythmias.

Adult↗
PubMed1985

Sulpiride and the potentiation of progestogen only contraception.

A progestogen (norethisterone) and a dopamine antagonist (sulpiride) were given alone and in combination to volunteers to examine their effects on excretion of ovarian steroids. Compared with non-treatment cycles (n = 15), contraception with a progestogen alone (n = 10) was associated with increased excretion of oestrone and partial suppression of excretion of pregnanediol, suggesting partial luteinization of unruptured follicles. By contrast, the combination of norethisterone and sulpiride (n = 9) suppressed both ovarian steroids to basal values, the suppression being even greater than with sulpiride alone (n = 5). These results suggest that a combination of a progestogen with a dopamine antagonist might have a role in contraception.

Adult↗
PubMed1985

Modifying the snack food consumption patterns of inner city high school students: the Great Sensations Study.

The Great Sensations Program is a nutrition-education project developed for high school students. It was designed to (a) decrease students' consumption of salty snacks and (b) increase students' consumption of fresh fruit snacks. The overall programs were designed following principles of social learning: informative instruction, participatory classroom activities, personal goal setting, feedback, and reinforcement. The program was delivered in six lessons during regular health-education classes. A parental involvement program consisted of mailers and telephone calls to parents to teach them to encourage changes in student snacking habits. A schoolwide program was designed to provide out-of-class peer support for student modifications in salty snack foods. The program was evaluated in one high school using a 2 X 2 design. A second high school served as a no-treatment control. Program assessments were made at both schools before and after the classes, at the end of the school year, and the following fall the next school year following summer vacation. The schoolwide media program was effective in decreasing consumption of salty snack foods and in increasing consumption of target snack foods. However, only those students receiving classroom instruction maintained those changes until the end of the school year. No changes were maintained across summer vacation. These outcomes suggest that school programs developed using principles of social learning may be effective in facilitating important behavior changes at home and at school.

Adolescent↗
PubMed1980

Management of aortic arch interruption with prostaglandin E1 infusion and microporous expanded polytetrafluoroethylene grafts.

Prostaglandin E1 infusion and a microporous expanded polytetrafluoroethylene graft were used in the management of eight infants, all less than 4 days old, with interruption of the aortic arch. Five of the six infants receiving prostaglandin E1 responded dramatically to this therapy, with return of lower limb pulses and lessening of metabolic acidosis. There were no adverse effects attributable to the prostaglandin E1 infusion. Seven infants subsequently underwent aortic reconstruction with a polytetrafluoroethylene graft. There were no operative deaths, and in up to 3 years of follow-up of these patients, graft obstruction occurred in only one patient and this graft was successfully revised. The long-term mortality rate was high (62 percent); all deaths but one were attributable either to the palliation or to the total correction of the associated cardiac malformations.

Aorta, Thoracic↗