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Biomedical subjects

K Ellis

Publications and source records attributed to K Ellis.

At least 19 recordsLinked to original sources

Surgical management of the infant with coarctation of the aorta and ventricular septal defect.

Clinical and cardiac catheterization data were collected from 39 infants with coarctation of the aorta and ventricular septal defect, 31 of whom were initially managed only by surgical repair of coarctation. Data were analyzed to determine mortality, morbidity, outcome and factors that might predict survival or the need for septal defect closure. Of the eight patients who did not require surgical treatment before 3 months of age, seven underwent coarctation repair alone at a mean age of 2.3 years. Of the 23 infants managed with coarctation repair alone, before age 3 months, 9 needed no additional surgical treatment and 6 required early and 8 required late repair of the ventricular septal defect. Seven infants underwent coarctation repair and simultaneous pulmonary artery banding and one eventually required debanding after spontaneous closure of the septal defect. The overall mortality rate in this series was 10.3% (mean follow-up time 5.7 years). Of 39 infants, 16 (41%) never required a second operation for ventricular septal defect closure. For patients who had only coarctation or coarctation repair with pulmonary artery banding at less than 3 months of age, ventricular septal defect size was categorized as small (less than 0.5 cm/m2), moderate (less than 1 cm/m2) or large (greater than 1 cm/m2) on the basis of defect size at operative repair or echocardiographic or angiographic assessment. Defect size did not necessarily correlate with the need for operative repair.(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic Coarctation

Delayed pneumothorax after subclavian vein catheterization and positive pressure ventilation.

Delayed pneumothorax may occur after subclavian vein catheterization and results from slow accumulation of air in the pleural space. Thus initial postinsertion chest x-rays may not detect this complication. The addition of positive pressure ventilation for general anaesthesia may make this complication life threatening. We report three cases and the literature is surveyed.

Aged

Fleischner lecture. Developmental abnormalities in the systemic blood supply to the lungs.

Developmental abnormalities in the systemic blood supply to the lungs occur in association with congenital heart disease, congenital lung disease, and rarely with apparently normal heart and lungs. Although most of these anomalies are rare, in the aggregate they are relatively common and of special interest to students of chest and heart disease.

Bronchopulmonary Sequestration

Prediction of cardiac and pulmonary complications related to elective abdominal and noncardiac thoracic surgery in geriatric patients.

PURPOSE: Major cardiac and pulmonary complications associated with abdominal and noncardiac thoracic surgery are a common cause of mortality and serious morbidity in elderly patients. We postulated that a simple, inexpensive bicycle exercise test could provide objective documentation of cardiopulmonary reserve and, therefore, predict perioperative pulmonary as well as cardiac complications. PATIENTS AND METHODS: Prior to elective surgery, 177 patients aged 65 years or older had assessment of the clinical history, results of physical examination, electrocardiogram, chest radiograph, blood chemistries, pulmonary function test findings, supine exercise test results, Dripps classification, and Goldman cardiac risk factors. Observations in patients with and without major perioperative cardiac and/or pulmonary complications were compared using univariate analysis followed by a multivariate logistic regression procedure. RESULTS: Major perioperative complications were pulmonary in 24 patients, cardiac in 25 patients, and either cardiac or pulmonary in 39 patients. By multivariate analysis, inability to perform two minutes of supine bicycle exercise raising the heart rate above 99 beats/minute was the best predictor of perioperative pulmonary, cardiac, and combined cardiopulmonary complication (p less than 0.0005). Among 108 patients who were able to achieve these exercise criteria, cardiac or pulmonary complications occurred in 10 patients (9.3%), with one death (0.9%). Among 69 patients unable to exercise satisfactorily, cardiac or pulmonary complications occurred in 29 patients (42%), with five total deaths (7.2%). CONCLUSION: Objective measurement of exercise capacity by supine bicycle ergometry appears to be of clinical value for preoperative risk stratification for both pulmonary and cardiac complications prior to major elective abdominal or noncardiac thoracic surgery in elderly patients.

Abdomen

Parathyroid hormone and calcitriol changes in normal and insulin-dependent diabetic pregnancies.

In pregnancy, an increase in serum calcitriol and parathyroid hormone concentrations has been reported in several studies, though the increase in parathyroid hormone remains controversial. In magnesium deficiency states, parathyroid hormone and calcitriol secretion may be decreased. Because magnesium deficiency may occur in insulin-dependent diabetic patients, mainly because of urinary magnesium losses, we hypothesized that serum parathyroid hormone and calcitriol do not increase in the diabetic pregnancy. We studied, in a prospective longitudinal manner, 35 nondiabetic and 199 insulin-dependent diabetic pregnancies. In diabetic women, the goals of glycemic control were fasting blood glucose below 100 mg/dL and postprandial blood glucose less than 140 mg/dL. Serum magnesium, calcium, parathyroid hormone (whole molecule; ie, 1-84 fragment), and calcitriol were measured three times: 1) 8-12 weeks, 2) 22-28 weeks, and 3) 32-38 weeks' gestation. In normal women, serum parathyroid hormone did not change significantly over pregnancy, and a wide scatter of values was observed. Serum calcitriol increased significantly with advancing gestation. In diabetic women, serum parathyroid hormone had a narrow scatter, but values were within the low-normal range. During the third trimester there was no increase, and even a decrease, in serum calcitriol concentrations. Diabetics had, throughout pregnancy, significantly reduced serum magnesium concentrations when compared with controls. Their serum calcium and ionized calcium concentrations were similar to those of controls, except in the third trimester, when diabetic women had significantly lower serum calcium and ionized calcium concentrations than controls. We speculate that mineral metabolism abnormalities in diabetic pregnancies might be due to relative magnesium and/or insulin deficiency.

Adult

When exercise can kill: how to spot IHSS.

For the patient who has idiopathic hypertrophic subaortic stenosis vigorous activity can be deadly. Identifying this condition and teaching the patient how to compensate may keep him alive.

Adult

Calcitriol in the treatment of postmenopausal osteoporosis.

Calcitriol was compared with placebo in the treatment of postmenopausal osteoporosis in a double-blind, randomized, parallel clinical trial of 24 months' duration. Adjustment was made in dietary calcium to maximize the dose of calcitriol. The study was completed by 15 patients who received placebo and 12 patients who received calcitriol. The calcitriol group had positive slopes (compared with negative slopes for the placebo group) for total body calcium, bone mineral content of the radius, bone mineral density of the lumbar spine, and radiographic absorptiometry of the middle phalanges. The difference between the two groups was statistically significant for each of these measurements. The fracture rate in the treatment group was 250 per 1,000 patient-years as compared with 333 for the placebo group. The mean dose of calcitriol was 0.8 micrograms per day. Hypercalcemia, hypercalciuria, and perhaps nephrolithiasis were observed as complications of treatment. Calcitriol increased bone mineral density by decreasing bone resorption, but not by increasing bone formation. Future studies should concentrate on treatment with oral calcitriol in lower doses. It would also be of interest to examine parenteral administration of calcitriol. It is possible that bone formation can be increased by achieving higher serum levels of the drug, whereas complications may be avoided by using a non-oral route of administration.

Aged

Evaluation of electrophoretic methods for typing methicillin-resistant Staphylococcus aureus.

Three electrophoretic methods of typing methicillin-resistant Staphylococcus aureus (MRSA) strains--plasmid profiles (PP), whole-cell protein profiles (WCPP) and immunoblotting profiles (IP)--were evaluated and compared with phage typing. The results obtained with isolates from 12 outbreaks were compared both within the outbreaks, to determine the consistency of results, and between outbreaks. There was generally good agreement between the typing methods but in only six outbreaks did all four methods indicate the same relationship between isolates. WCPP comprised more than 50 bands; when differences occurred, they were seen in only a few bands. In contrast, IP comprised only one or two major bands and the differences were much easier to interpret. The PPs of many of the isolates were similar; many isolates contained a plasmid of mol. wt (18-25) x 10(6). In several outbreaks both WCPP and IP showed minor differences between isolates that were not apparent with phage typing. When comparisons were made between the 12 index strains and an isolate representing the London epidemic MRSA strain, phage typing and WCPP were the most discriminatory methods; both gave nine distinct patterns, whereas there were eight IPs and only six PPs amongst the 13 strains. It was concluded that both WCPP and IP could provide valuable epidemiological data on MRSA and that IP was the easiest of the three methods to interpret.

Bacterial Proteins

Radiologic detection of thymoma in patients with myasthenia gravis.

From 1973 through 1986, 154 consecutive patients who had a transsternal thymectomy for myasthenia gravis had preoperative radiologic evaluation for a possible thymoma. Examinations included posteroanterior and lateral (n = 154) and shallow oblique (n = 126) chest radiography, linear tomography (n = 80), and chest CT (n = 96). At surgery, a thymoma was found in 26 patients (17%). Plain film findings, which often were subtle, correctly predicted a thymoma in 15 (58%) of 26 patients. CT findings correctly predicted a thymoma in 17 of 20 patients (sensitivity, 85.0%; specificity, 98.7%; and accuracy, 95.8%). CT findings failed to detect a thymoma in three patients because a small tumor was indistinguishable from adjacent thymus (n = 2) and respirator motion artifacts (n = 1). Four (15%) of the tumors were invasive, and three (12%) were calcified. The likelihood of a thymoma increased with increasing age (3% for 20 years old and under, 12% for 21-45 years old, and 35% for 46 years old and older). In the youngest group, the thymus is densely cellular and normally relatively large, and therefore a small thymoma may be hidden. In patients 21-45 years old, partial fatty involution leaves parenchymal islands that can mimic a thymoma or obscure a small tumor. In patients over 45 years old, fatty involution enhances recognition of even small thymic tumors. For all patients with myasthenia gravis, we recommend that the initial chest radiographic examination include posteroanterior, lateral, and shallow (20 degrees) oblique views. For those patients under 21 years old, we recommend chest CT only when local symptoms, signs, or radiographic findings suggest the presence of thymic abnormality. For those patients 21 years old and older, we recommend routine chest CT.

Adolescent

Tn2501, a component of the lactose transposon Tn951, is an example of a new category of class II transposable elements.

Tn2501 is a cryptic class II transposon found as part of the lactose transposon Tn951. Insertional inactivation and nucleotide sequence analysis of Tn2501 allowed us (i) to localize the transposase (tnpA) and the resolvase (tnpR) genes as well as the resolution site (res) of Tn2501 and (ii) to compare Tn2501 with other well-known elements of the two subgroups of class II transposons (Tn3, gamma delta, Tn951, IS101; and Tn21, Tn501, Tn1721). The genetic organization of Tn2501 is similar to that of Tn3 with divergent transcription of the tnpA and tnpR genes away from the intervening res site. The tnpR gene of Tn2501 shows weak homology with that of Tn3 and even less with those of Tn21 and Tn501. However, the tnpA gene and the inverted repeat sequences of Tn2501 present more homology with those of Tn21 and Tn501 than with those of Tn3. Complementation studies showed that TnpA- mutants of Tn2501 can be complemented, at a low frequency, by the Tn21 transposase. None of the tested transposons complemented TnpR- mutants of Tn2501.

Amino Acid Sequence