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Biomedical subjects

K Ellis

Publications and source records attributed to K Ellis.

At least 73 records · Page 4Linked to original sources
PubMed1983

Determinants of bone mass in postmenopausal women.

Eighty white women, mean age 52 years, within one to six years postmenopausal, were studied to examine the relationship of various factors to bone mass. Forty-four of the women had annual measurements of bone mass, so that the rate of bone loss could be determined. Bone mass was measured by total body neutron activation analysis and photon absorptiometry of the distal radius (total body calcium [TBCa] and bone mineral content [BMC], respectively). Breast-feeding and pregnancy were noted to be associated with higher bone mass; those with lower BMC and/or TBCa tended to have higher serum alkaline phosphatase levels, lower testosterone levels, and more years since the cessation of menses. The rate of bone loss from the radius was greater in those with higher parathyroid hormone levels; those with reduced dietary intake of calcium and lower 25-hydroxyvitamin D levels had a greater rate of loss of TBCa.

Bone and Bones↗
PubMed1982

pHH502, a plasmid with IncP and IncI alpha characters, loses the latter by a specific recA-independent deletion event.

Plasmid pHH502, of molecular weight 70 X 10(6), determined resistance to tetracycline, chloramphenicol, trimethoprim, sulphonamides and mercuric chloride and was incompatible with members of IncP and IncI alpha. It resembled other plasmids of IncI alpha in the following properties: it determined pili that were morphologically and serologically I alpha pili, whose production was repressed in established plasmid-carrying (R+) cultures; its transfer was equally efficient in liquid or on solid medium; it exerted surface exclusion against other IncI alpha plasmids; it was non-transferable to Proteus. In a reproducible, recA-independent event, pHH502 gave rise to pHH502-1, a plasmid of molecular weight 40 X 10(6), lacking determinants for resistance to tetracycline and chloramphenicol and all detectable IncI alpha characteristics. pHH502-1 was incompatible only with IncP plasmids and resembled other IncP plasmids in determining constitutive production of rigid pili, in its surface exclusion, in transferring at greater frequency on solid than in liquid medium and in being transmissible to Proteus mirabilis. It differed from other IncP plasmids in the morphology and serological type of its pili and in failing to transfer to Pseudomonas aeruginosa or Acinetobacter calcoaceticus. Small numbers of pHH502-1 rigid pili were present on bacteria carrying pHH502. Possible mechanisms for the generation of pHH502 and pHH502-1 are discussed.

Bacteria↗
PubMed1982

Combination therapy for osteoporosis with estrogen, fluoride, and calcium.

Nine women with postmenopausal spinal osteoporosis were treated with combination therapy consisting of estrogen, fluoride, and calcium. Their data were compared with those of a control group treated with fluoride, and calcium without estrogen. Bone mass was measured about every six months by photon absorptiometry (bone mineral content/bone width (BMC/BW)] and total-body neutron activation analysis [total-body calcium (TB Ca)]. Time-trend analysis revealed positive slopes for TB Ca (P = 0.002) and BMC/BW (P = N.S.) for the combination therapy group. The change in BMC/BW in the combination therapy group was significantly different from the response in the fluoride - calcium group. These data suggest that combination therapy may be successful in increasing bone mass in postmenopausal osteoporosis. A clinical trial to establish efficacy and examine risk/benefit ratios should be performed.

Adult↗
PubMed1981

Muscular ventricular septal defects repaired with left ventriculotomy.

Between 1974 and 1979 nine patients, aged 10 months to 4 years, underwent left ventriculotomy for closure of single or multiple defects in the muscular ventricular septum. The vertical incision paralleled the anterior descending branch of the left coronary artery near the apex of the left ventricle and ranged from 2.5 to 3.5 cm in length. Four patients also had a right ventriculotomy with closure of a high perimembranous ventricular defect in two. Serial electrocardiograms indicated changes of myocardial ischemia or necrosis. Left bundle branch block did not develop in any patient. Three patients died in the early postoperative period. The six surviving patients are living and well 2 to 7 years later. There is apparent complete closure of the ventricular defects, which was documented by cardiac catheterization in four cases. Two patients had cardiomegaly and left ventricular dysfunction as assessed with echocardiographic and angiographic study, whereas four displayed good cardiac function. In three of the latter patients, cardioplegia or deep hypothermia techniques were utilized intraoperatively. The observations indicate that left ventriculotomy of limited size is an acceptable approach to the difficult problem of repair of muscular ventricular defects but may involve some risk of compromise of the coronary circulation.

Child, Preschool↗
PubMed1980

Total-body sodium and sodium excess.

Total-body levels of sodium (TBNa), chlorine (TBCl), calcium (TBCa), and potassium (TBK) were measured by neutron activation and analysis of results by whole body counting in 66 postmenopausal women. The relationship between TBNa, and TBCl, TBK, and TBCa on the one hand, and height and weight on the other, were found to compare with those previously reported. The hypothesis that TBNa and TBCl are distributed normally could not be rejected. The sodium excess (Naes) is defined as the sodium that is present in excess of that associated with the extracellular fluid (chlorine) space; the Naes approximates nonexchangeable bone sodium. In these 66 postmenopausal women, and in patients with different endocrinopathies previously described, the values of Naes did not differ from the normal values except in the thyrotoxicosis patients, where they were decreased. A close relationship between Naes and TBCa was maintained in the endocrinopathies studied. This relationship was found in conditions accompanied by either an increment or a loss of skeletal mass. It appear

Body Composition↗
PubMed1979

Pulmonary atresia with intact ventricular septum. Sixteen-year experience.

Infants with pulmonary atresia and intact ventricular septum (PA-IVS) usually require urgent surgical intervention. Thirty patients with this anomaly, seen at the Columbia-Presbyterian Medical Center between 1962 and 1978, had palliative operations, 26 within the first 3 days of life. Six underwent a closed pulmonary valvotomy alone, with no survivors; six had only a systemic--pulmonary artery shunt, with three early survivors. Because of this experience, 17 had a combined procedure of valvotomy and shunt, with 14 early survivors. One patient recently underwent a definitive right ventricular outflow patch procedure with cardiopulmonary bypass. Eight patients subsequently have had corrective open-heart procedures, with five patients surviving from 2 to 10 years. A unicusp aortic homograft was used for repair in five and a Hancock valved conduit in three. Four patients are presently awaiting operation. We conclude that the initial surgical management of these critically ill infants must not only increase pulmonary blood flow but in addition provide an opportunity for right ventricular growth. Thus we continue to advocate the combined procedure of a valvotomy plus a shunt to provide adequate palliation. Repeat catheterization should be performed within a year to confirm the adequacy of the valvotomy, since this is essential to maximal right ventricular enlargement and to allow for definitive correction at a later date.

Adolescent↗
PubMed1978

Skeletal mass in postmenopausal women.

The techniques of photon absorptiometry of the radius and total body neutron activation analysis were used for the determination of bone mineral content and total body calcium, respectively. The subjects consisted of 71 normal women who were 1-5 yr postmenopausal and 44 osteoporotic women who had crush fractures of the dorsal spine. Both bone mineral content and total body calcium were corrected for age and body size by using the ratio of observed values to those predicted from previously derived equations. Discrimant analysis involving both osteoporotic and normal postmenopausal women resulted in the successful assignment of 81% of the 115 subjects to their correct group. Statistical analyses of the distribution of the bone mass of the postmenopausal women yielded no evidence to support the hypothesis that a subgroup exists with bone mass levels markedly different from the remainder of the women.

Aged↗
PubMed1978

Reduced left ventricular myocardial blood flow per unit mass in aortic stenosis.

Myocardial blood flow (MBF) per unit mass was measured in 10 patients (pts) with severe aortic stenosis (AS) and no significant aortic insufficiency, normal ejection fractions, and normal coronary arteriograms, using xenon-133 and a multiple crystal scintillation camera. MBF per unit mass was reduced in AS (53 +/- 13 mg/100g.min) in comparison to a group of seven normal control patients (69 +/- 12 ml/100g.min) (P less than 0.05). When normalized for heart rate. MBF remained depressed in aortic stenosis (0.65 +/- 0.11 ml/100 g.beat). MBF/beat was strongly related to peak left ventricular wall stress in both groups (r = 0.97). Individual values of MBF/beat were normalized for peak stress using an analysis of covarience; the adjusted mean values were 0.62 +/- 0.03 ml/100g.beat for the AS patients and 0.84 +/- 0.03 ml/100 g.beat for the control patients. There was no overlap between groups in adjusted MBF per beat. Values of MBF per beat and peak stress for a group of ten cardiomyopathy patients with depressed contractility were observed to fall close to the regression line for AS patients. The results suggest that variability in resting MBF in these AS patients is due primarily to differences in LV stress and that reduction in MBF per beat in this group may be due to reduced contractility.

Aortic Valve Stenosis↗
PubMed1978

Hydroxyproline peptides and bone mass in postmenopausal and osteoporotic women.

Total and nondialyzable hydroxyproline excretion was measured in 59 postmenopausal women and 68 women with spinal osteoporosis. Hydroxyproline excretion was similar in both groups of women and the hypothesis that hydroxyproline excretion is normally distributed could not be rejected for either group. No relationship was found between hydroxyproline excretion (total and percentage of nondialyzable) and body weight, height, body surface area, or total body calcium or bone mineral content of the radius, or these latter values normalized for age, sex, and body size. There was no difference in hydroxyproline excretion in osteoporotic women who took supplemental calcium as compared to those that did not. These data fail to provide any evidence that bone turnover in osteoporotic women differs from that in younger postmenopausal women, or that osteoporosis arises from a subpopulation of women with rapid bone loss.

Body Height↗
PubMed1978

Prevention of involutional bone loss by exercise.

To ascertain whether exercise could prevent involutional bone loss, we studied 18 postmenopausal women, half of whom exercised for 1 h three times a week. Total and regional bone mass were measured before and after 1 year of exercise by the techniques of total-body neutron activation analysis (total body calcium) and photon absorptiometry (bone mineral content) of the distal radius. Total body potassium was measured by whole body counting. Bone mineral content and total body potassium did not change significantly in either group. Total body calcium increased in the exercise group from 781 +/- 95 g of 801 +/- 118 g (SD). In contrast, total body calcium decreased in each subject in the sedentary group. The daily calcium balance derived from the difference in total body calcium measurements was significantly different in the two groups of women (P less than 0.001). These data support the hypothesis that exercise can modify involutional bone loss.

Bone and Bones↗
PubMed1978

The effects of minor degrees of obliquity on the lateral chest radiograph.

Minor degrees of obliquity affect the appearance of the lateral chest radiograph. For 100 normal subjects we compared findings on three left lateral projections: the "straight lateral", rotation of the subject's right side 10 degrees anterior ("right anterior"), and rotation of the patient's right side 10 degrees posterior ("right posterior"). A number of structures appeared generally best seen in the "right anterior" lateral projection, less well seen in the "straight posterior" lateral projection and least well seen in "right posterior" lateral projection. These structures were the epicardial fat stripe and pericardial line, the anterior margin of the ascending aorta, the hilar vessels, the origins of the upper lobe bronchi, and the posterior wall of the bronchus intermedius. The heart appeared largest in the "right anterior" lateral view, while in the "right posterior" lateral view it appeared smallest (whether assessed subjectively or by measurement of posterior left ventricular overlap of the inferior vena cava). Similarly, the hilar vascular shadows and major bronchi were most prominent when rotated apart in the "right anterior" projection and least prominent when more nearly superimposed in the "right posterior" projection. Slight rotation showed no significant effect on the anteroposterior diameter of the trachea, the width of the left pulmonary artery, or the diameters of the upper lobe bronchi. The azygos vein and a well visualized posterior tracheal band were seen in a few patients. They tended to be best and most frequently seen in the "right posterior" lateral view. Either obliquity tended to improve delimeation of the anterior pleural margins and the costophrenic angles. This was also true for the interlobar fissures, but confusing superimposition shadows were less likely in the "right anterior" than the "right posterior" lateral radiograph.

Aortography↗
PubMed1977

Combination therapy for osteoporosis.

The effect of therapy that simultaneously stimulates bone formation and inhibits bone resporption was evaluated in five patients with primary osteoporosis. The technique of in vivo neutron activation analysis was used to measure total body calcium (TB-Ca). The patients were treated with calcium supplements and salmon calcitonin combined with either a low or a high dose of growth hormond (hGH). There was no significant increase in skeletal mass (TB-Ca) during the low-dose hGH regimen. An increase in skeletal mass was observed in all patients following the high-dose regimen, except for one patient who developed secondary hyperparathyroidism. Although this study must be considered to be of a preliminary nature, the magnitude of the response in calcium balance suggests that skeletal mass can be increased in osteoporosis if combination therapy is employed.

Absorption↗