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Biomedical subjects

A Lorber

Publications and source records attributed to A Lorber.

At least 37 records · Page 2Linked to original sources
PubMed1998

Uptake of ingested uranium after low "acute intake".

The uptake of uranium, ingested as a soluble compound, was studied by monitoring the uranium level in urine by inductively coupled plasma mass spectrometry and through measurement of an isotopic tracer. The high sensitivity of this method allows measurement of uranium levels in urine samples from each voiding, therefore more detailed biokinetic studies are possible. To simulate low "acute intake," five volunteers with "normal" levels (5-15 ng L(-1)) of uranium in urine ingested a grapefruit drink spiked with 100 microg of uranium (235U/238U = 0.245%) as uranyl nitrate, and the level of uranium in their urine after ingestion was monitored. Two techniques were applied to estimate the extent of exposure: a) uranium levels above the normal level for each volunteer; and b) the deviation from natural isotopic ratio. Results were normalized relative to the creatinine concentration, which served as an indicator of urine dilution, to reduce effects due to diurnal changes. The results clearly indicate that currently accepted bio-kinetic models overestimate the time between ingestion of dissolved uranium and its excretion in urine, the maximum of which was found to be around 6-10 h. The uptake fraction was in agreement with recent studies, i.e., 0.1-0.5% of the ingested uranium for four of the subjects but above 1.5% for the fifth, and well below the 5% reported in International Commission on Radiation Protection Publication 54. Finally, partial results from the isotope dilution study indicate that uranium absorbed through the intestine interchanges with uranium retained in body organs. The time scale of this process is quite short, and the acute exposure led to a minimum in the isotopic ratio within hours, while recovery back to natural abundance due to low chronic exposure takes several days.

Adult↗
PubMed1998

GH dependence and GH withdrawal syndrome in GH treatment of short normal children: evidence from growth and cardiac output.

The child's age is a significant determinant of the outcome of GH therapy; prepubertal children respond better on both short term and long term growth, whereas adolescents tend to accelerate their bone maturation more than growth. The present study was designed to evaluate the efficacy of an interrupted GH therapy protocol of young, short normal children. GH was given for a period of 3 years, or until they reached the 25th percentile, then discontinued at a young age (not more than 9 years), and then the children's growth followed until final height. Yet, after discontinuation of GH therapy, growth came close to a complete stand-still. The present report focuses on describing the period beyond GH withdrawal and its impact on growth and cardiac performance. Twenty-two children received daily s.c. injections of 0.9 mg/m2 hGH and 12 children were the control, untreated group. Growth and echocardiography were followed during therapy and 2 years thereafter. During GH treatment growth velocity accelerated markedly over the first year; it slowed down over the second and third years, and decelerated after GH withdrawal to a velocity that was significantly lower than pretreatment values. Growth rate remained low for the next year, and recovered to pretreatment velocity by the fourth semiannual measurement. To evaluate the role of the GH-IGF-I axis during the growth deceleration, serum IGF-I, insulin-like growth factor-binding protein-3 (IGFBP-3), and an arginine stimulation test were performed at 1, 3 or 6 months after GH withdrawal, and compared with pretreatment response. GH response was 70% of pretreatment values by 1 month and recovered completely by 3 months post treatment. Serum IGF-I and IGFBP-3 levels were normal throughout. End-systolic and end-diastolic left ventricular dimensions as well as cardiac output did not change during the 2 year course of GH therapy, but fell significantly during the initial 6 months of GH withdrawal. Thus, daily injections of GH to prepubertal short normal children is associated with development of drug dependence, followed during the abstinence period by deceleration of growth and reduction of cardiac output to levels that are lower than pretreatment values. After GH therapy for 30-36 months the withdrawal syndrome persists for 18 months, and is not induced by alterations of serum levels of GH or IGF-I.

Body Height↗
PubMed1997

Punch pulmonary valvectomy: another alternative to treat critical pulmonary stenosis.

For neonates with severe valvar stenosis, or valvar pulmonary atresia with an imperforate pulmonary valve, we present a simple but effective closed procedure using a specially designed valvectomy punch. Seven neonates, who were not suitable for any type of transcatheter procedure, were treated. There were two late deaths, neither directly related to the operation; 4 patients are developing well. This approach using the valvectomy punch is a fast, safe, and effective procedure.

Cardiac Surgical Procedures↗
PubMed1996

Inductively coupled plasma mass spectrometry as a simple, rapid, and inexpensive method for determination of uranium in urine and fresh water: comparison with LIF.

A simple method, based on inductively coupled plasma mass spectrometry, for determination of uranium in urine at levels that indicate occupational exposure, is presented. Sample preparation involves a fifty-fold dilution of the urine by nitric acid (2% HNO3) and no other chemical treatment or separation. The analysis itself is completed in under 3 min. The analytical procedure is fully automated so that a technician may perform over 100 analyses per day. With proper control of the blank contribution, a lower limit of detection of 3 ng L(-1) in the original urine sample was achieved. Uranium concentrations in the range 6-30 ng L(-1) were found in urine samples of people that are not occupationally exposed. The validity of the results was demonstrated through measurement of standards, controlled uranium addition experiments and, at higher concentrations, by comparison with results obtained by an independent method based on laser induced fluorescence. The laser induced fluorescence technique was found to be sufficient for detection of occupational exposure at an action level of 1.5 microg L(-1). Use of internal standards, indium, and thallium, improved quantification by about 10%, but was not deemed necessary for routine analysis. The inductively coupled plasma mass spectrometry is also ideally suited for monitoring uranium in fresh water and drinking water, as no sample dilution is required and the lower limit of detection is below 0.15 ng L(-1).

Humans↗
PubMed1995

The presence of antiphospholipid antibodies in acute myocardial infarction.

This study was undertaken to determine if there is an association between increased titers of five different antiphospholipid antibodies (aPLA) in young patients' sera and the occurrence of acute myocardial infarction (AMI). Antibodies to anticardiolipin (aCL), anti-phosphatidylserine (aPS), antiphosphatidylinositol (aPI), anti-phosphatidylcholine (aPC), and anti-phosphatidylethanol amine (aPEA) were measured in 214 patients (102 patients, 102 healthy controls and 10 patients with antiphospholipid syndrome). These antibodies were measured twice (within 4h of onset of acute myocardial ischemic chest pain and 3 months after the myocardial infarction) by enzyme linked immunosorbent assay (ELISA). Elevated titers of four different aPLA were detected in 6.9% of all patients with AMI on hospitalization. Titers of aPLA in AMI were elevated in the younger age group < 50 years old (P < 0.001) and in men only (not statistically significant). No correlation was found between the presence of aPLA and cardiovascular risk factors (smoking, hypertension, diabetes mellitus and hyper-cholesterolemia). Three of the seven patients with increased titers of aPLA did not have any other cardiovascular risk factors. The titers of aPLA were within normal range 3 months after AMI. Evidence of significantly elevated titers of different aPLA at the early stage of AMI suggests that these autoantibodies are present before the AMI and are not secondary to them. The disappearance of the elevated aPLA 3 months after AMI may be due to an absorption effect or possibly a cyclic phenomenon similarly found in other autoimmune diseases. aPLA may be an additional risk factor for AMI, and should especially be considered in a patient of the younger age group without apparent cardiovascular risk factors.

Adult↗
PubMed1994

Deletion of the short arm of chromosome 10 (10p13): report of a patient and review.

Since the first description by Elliot et al. [1970, Am J Dis Child 119:72-73] of a probable partial deletion of chromosome 10p, 17 other cases have been reported. The phenotypic expression is variable, but the craniofacial malformations constitute a more consistent finding. The 10p deletion syndrome has been associated with the DiGeorge anomaly in several patients. We report on an additional case of 10p deletion syndrome and review the literature.

Child, Preschool↗
PubMed1993

Early ultrasound diagnosis of fetal congenital heart defects in high-risk and low-risk pregnancies.

OBJECTIVE: To evaluate the yield of early second-trimester transvaginal ultrasonography in the detection of congenital heart defects among patients with low or high risk for fetal anomalies. METHODS: During 5 years, we performed 12,793 transvaginal ultrasound examinations at 12-16 weeks' gestation, targeted for detection of fetal congenital anomalies. Three thousand four hundred fifty-three (27%) of these patients were considered to be at high risk for fetal congenital heart defects (because of family or medical history or teratogen exposure). The other 9340 patients were considered to be at low risk for fetal anomalies. The four-chamber view and the outflow tracts were evaluated systematically in all patients. RESULTS: Congenital heart malformations were observed in 47 cases, most of which (29 of 47) were diagnosed in the low-risk group. Additional extracardiac malformations were observed in 29 (62%) of the affected fetuses. Ten of 28 affected pregnancies that were karyotyped (36%) had abnormal chromosomes. Use of the four-chamber view alone would have failed to detect 11 (23%) of the abnormal fetuses. CONCLUSIONS: Transvaginal ultrasonography in the early second trimester is a useful tool for the detection of fetal cardiac structural defects, provided that both the four-chamber view and the outflow tracts are evaluated. When such an anomaly is suspected, additional fetal malformations should be sought and fetal karyotype should be determined.

Chromosome Aberrations↗
PubMed1992

[Congenital arteriovenous facial fistula cured by percutaneous embolization].

Arteriovenous fistulas of the external carotid artery are uncommon. They are usually of traumatic origin but in rare cases may be congenital. When located in regions with difficult access, they constitute a difficult surgical problem because of intra-operative bleeding and significant morbidity. With the advent of transcatheter embolization and new embolic agents, embolization has become the treatment of choice, with a cure rate of over 95%, low morbidity and brief hospitalization. Occlusion of the fistula itself, rather than occlusion of feeding pedicles, is achieved by super-selective catheterization and the use of a suitable permanent embolic agent, depending on location of the fistula and its flow characteristics. A girl aged 2 10/12 with a large, high-flow, arteriovenous fistula of the internal maxillary artery is presented. Complete occlusion of the fistula itself, with full cure, was achieved by super-selective transcatheter embolization using Gianturco coils. There has been no recurrence after more than 7 months of follow-up.

Arteriovenous Fistula↗
PubMed1989

[Echocardiographic diagnosis of anomalous origin of left coronary artery].

Cross sectional and M-mode echocardiography is a well-established noninvasive technique in the diagnosis of dilated cardiomyopathy and is essential in the evaluation of its severity and progress. However, in most cases of dilated cardiomyopathy in children, it does not provide data suggestive of the etiology of the disease. In the rare congenital malformation, anomalous origin of the left coronary artery from the pulmonary artery, the echocardiographic techniques may suggest the diagnosis when the left coronary artery cannot be demonstrated to arise from its usual site, the left coronary sinus (as visualized in the short axis of the aortic root). A firm diagnosis can be made if the anomalous origin of the left coronary artery is identified in a cross-sectional view of the main pulmonary artery (left parasternal long axis view of the main pulmonary artery, Fig. 1). This was demonstrated in a 9-year-old girl by coronary and aortic angiography (Fig. 2a, b). Anatomical confirmation was made during corrective surgery 3 months later. The origin of the left coronary artery was at the left posterior aspect of the main pulmonary artery, just proximal to its bifurcation. This is an unusual origin in this anomaly in which the coronary artery has been reported to arise close to the pulmonary valve, but not distal, as in this case.

Child↗
PubMed1989

Early detection of infantile endocarditis by gallium--67 scintigraphy.

An infant with suspected soft tissue infection of the knee was studied by 67Ga-scintigraphy. In addition to knee and hip joint increased activity, heart uptake was also demonstrated prior to the development of clinical signs of endocarditis. The early detection and treatment resulted in satisfactory clinical resolution.

Endocarditis, Bacterial↗
PubMed1988

Bedside demonstration of the absence of the right pulmonary artery in a premature baby.

Bedside demonstration of the absence of the right pulmonary artery was made in a premature baby in the neonatal intensive care unit. Antegrade venous and retrograde aortic injections of contrast material excluded the possibility of the anomalous origin of the right pulmonary artery from the aorta, and suggested the above-mentioned diagnosis, with the addition of a ventricular septal defect and a right-to-left shunt.

Female↗
PubMed1988

R wave amplitude changes during stress testing in ischemic patients with normal epicardial coronary arteries.

R wave amplitude changes during stress testing were validated in 12 ischemic patients with normal coronary angiograms. The data were compared with findings obtained from 10 patients with clinical and angiographic evidence of coronary arterial disease and 10 normal controls. An abnormal R wave amplitude response occurred in 83.3% of the group with normal coronary angiography, in 80% of the group of patients with clinical and angiographic evidence of coronary arterial disease, and in only 10% of the control group. The similarity of R wave amplitude changes in the first two group suggests that these changes are related to ischemia. If so, then R wave amplitude response to exercise could be of value in the electrocardiographic diagnosis of ischemia in patients with angiographically normal coronary arteries.

Adult↗
PubMed1988

The scale of myocardial involvement in varicella myocarditis.

Two patients with varicella myocarditis are described. An arrhythmia associated with complete recovery occurred in the first patient whereas intractable congestive heart failure complicated by hemiplegia resulted in a fatal outcome in the other case. We stress the extent of myocardial involvement produced by the herpes zoster virus in the setting of varicella.

Cardiac Output↗
PubMed1988

Hereditary right axis deviation: electrocardiographic pattern of pseudo left posterior hemiblock and incomplete right bundle branch block.

We present a family with a hereditary electrocardiographic pattern of pseudo left posterior hemiblock and incomplete right bundle branch block which resulted in right axis deviation. The mother had a normal electrocardiogram, while the father and their two sons presented the above-described electrocardiographic features. Clinical, radiological and echocardiographic evaluation excluded structural and functional cardiac abnormalities as well as chest deformities and lung disease. The identical vectorcardiographic findings of the father and his sons is discussed.

Adolescent↗
PubMed1987

Torsade de pointes complicating atrioventricular block: report of two cases.

One patient with complete atrioventricular heart block and another with high-degree atrioventricular block, complicated by "torsade de pointes" are presented. Both patients were symptomatic. One had a syncopal episode and the other presented with signs and symptoms of congestive heart failure. The electrocardiographic phenomena of torsade de pointes was repeatedly recorded. No other known predisposing factors for torsade de pointes were identified. The use of right ventricular endocardial pacing suppressed the paroxysms in both patients.

Aged↗