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Biomedical subjects

G Baumann

Publications and source records attributed to G Baumann.

At least 163 records · Page 9Linked to original sources
PubMed1996

Preoperative two- and three-dimensional transesophageal echocardiographic assessment of heart tumors.

BACKGROUND: Two-dimensional transesophageal echocardiography is the most widely used diagnostic approach in the rare entity of heart tumors. The aim of this study was to assess the diagnostic usefulness of three-dimensional echocardiography in comparison with the two-dimensional technique in a rare clinical setting. METHODS: Twenty-seven patients (18 women; mean age, 49.7 +/- 14 years) with a histologically proven diagnosis of a cardiac tumor were studied. The primary diagnosis was done by a two-dimensional transthoracic echocardiography (n = 9) and transesophageal echocardiography (n = 18). In addition, we performed three-dimensional transesophageal assessment in 5 patients with left atrial myxomas. The echocardiographic findings were compared with the intraoperative appearance and pathologic diagnosis. RESULTS: The echocardiographically suspected diagnosis of a heart tumor in 29 cases was histologically correct in 27 patients (myxomas, 20; epicardial lipoma, 1; malignant epicardial mesothelioma, 1; metastatic processes of hypernephromas, 2; and undifferentiated tumors of the pericardium, 3). Only the combination of multiplane transesophageal and three-dimensional echocardiography was able to demonstrate the shape, dimensions, location, origin, surface, three-dimensional movement, and involvement of valves and was most useful in the preoperative diagnosis and planning. CONCLUSIONS: Three-dimensional transesophageal echocardiography yields important additional clinical information and improves the operative planning. Three-dimensional echocardiography may become the best approach to study the anatomy and pathology of the heart as it provides an objective display of cardiac size and shape in heart tumors.

Adult↗
PubMed1996

Multiplane transoesophageal echocardiography is the only definitive ultrasound approach in adult supravalvular aortic stenosis.

This report describes a rare case of isolated supravalvular aortic stenosis (SVAS) in a 28 year-old female patient. A congenital heart defect, diagnosed at birth, was until 1994 suspected to be a valvular aortic stenosis (VAS). Cardiac catheterization led to the diagnosis of supravalvular aortic stenosis, which could easily be confirmed by multiplane but not by monoplane transoesophageal echocardiography (TEE). Precordial examinations had not revealed the vitium, probably because the SVAS is a rare malformation of the ascending aorta, but with multiplane TEE the aortic narrowing could be imaged clearly and pressure gradients comparable to those found with invasive measurements were established. The advantage of this non-invasive method for diagnosis and preoperative preparation are discussed in detail.

Adult↗
PubMed1996

Removal of autoantibodies in dilated cardiomyopathy by immunoadsorption.

Immunoadsorption with Ig-Therasorb leads to a marked decrease in serum levels of immunoglobulins including of the agonist-like anti-beta 1-adrenoceptor autoantibody found in the serum of patients with idiopathic dilated cardiomyopathy. The reduction in autoantibody levels was accompanied by an improvement of heart function and a shift to a lower NYHA state. In this disease, as in a variety of other autoimmune disorders, apheresis with Ig-Therasorb led to a rapid improvement of the clinical status and could be used in end-stage dilated cardiomyopathy (with autoantibodies) as a bridge for transplantation.

Autoantibodies↗
PubMed1996

Angioscopic evaluation of atherosclerotic plaques: validation by histomorphologic analysis and association with stable and unstable coronary syndromes.

OBJECTIVES: We validated coronary angioscopic observations with histologic assessment of material removed by atherectomy. BACKGROUND: Up to now, angioscopic findings have been primarily descriptive, and the clinical significance still needs to be substantiated. The proposed Ermenoville classification is relevant but has not yet been validated by histomorphologic analysis. METHODS: We compared angioscopic findings in patients with different coronary syndromes and used atherosclerotic material retrieved by directional coronary atherectomy to validate the angioscopic observations. Coronary angioscopy was performed in 63 patients (56 men, 7 women) with stable (26 patients) and unstable angina (37 patients) before and after directional coronary atherectomy. The identity of atherectomized material was confirmed by ex vivo visualization with the angioscope and by postatherectomy angioscopy. Angioscopic and histologic findings could be compared in 44 of 63 patients. RESULTS: Angioscopic findings were grouped into gray-white and yellow lesions (gray-yellow, deep yellow, yellow-red or yellow-pink). We found that patients with unstable angina had predominantly yellow lesions (89%). In patients with stable angina, gray-white (43%) or yellow (57%) lesions were similarly distributed. Ruptured yellow plaques and red or pink thrombi were identified in 11% of patients with stable angina and 39% of patients with unstable or early postmyocardial infarction angina. Histologically, gray-white lesions represented fibrous plaque without degeneration in 64% and with degeneration in 36% of patients. Gray-yellow lesions were associated predominantly with degenerated plaque (64%) and, to a lesser extent, with fibrous plaque (14%) or atheroma (14%). Deep yellow and yellow-red lesions represented either atheroma (53%) or degenerated plaque (42%). CONCLUSIONS: Our study establishes a histomorphologic basis for classification and interpretation of angioscopic findings. Yellow plaque color is closely related to degenerated plaque or atheroma and is associated with unstable coronary syndromes.

Angina Pectoris↗
PubMed1996

Androgen regulation of growth hormone binding protein.

Male puberty is associated with elevated plasma concentrations of growth hormone (GH) and insulin-like growth factor-I (IGF-I), as well as accelerated linear growth. These effects can be reproduced by administration of testosterone (T). To further elucidate the mechanisms underlying pubertal growth, we treated 14 boys with delayed puberty and short stature with either T (n = 7) or 5alpha-dihydrotestosterone (DHT) (n = 7) and compared the effect on plasma concentrations of GH, IGF-I, and GH binding protein (GHBP). Before treatment and after either three or four doses of T enanthate or DHT heptanoate, mean 12-hour GH concentration (8 AM to 8 PM) and plasma IGF-I, T, DHT, and GHBP levels were measured, and height velocity (HV) was measured over this interval. T treatment resulted in an increase of mean GH from 3.3 to 12.0 microg/L (P < .005) and of IGF-I from 22.3 to 45.4 nmol/L (P < .01). During treatment, HV was 11.0 +/- 1.1 cm/yr, consistent with normal pubertal growth, and plasma T was 22.5 +/- 5.3 nmol/L. GHBP decreased in this group from 937 to 521 pmol/L (P < .025). DHT treatment resulted in a small decrease of mean GH from 4.3 to 2.9 microg/L (P < .025) and of IGF-I from 29.4 to 27.2 nmol/L (nonsignificant [NS]). During treatment, HV was 9.3 +/- 1.1, not significantly different from the HV obtained with T treatment, and plasma DHT was 24.2 nmol/L at 1 week and 29.2 at 2 weeks postinjection. Likewise, there was a decrease in GHBP from 928 to 698 pmol/L (P < .025). The decline in GHBP with T treatment was apparently due to an androgen receptor-dependent mechanism, since the same effect was seen during treatment with the nonaromatizable androgen, DHT. This effect is opposite to the normal chronological trend upward for GHBP, which occurs from infancy into midpuberty. Factors determining the upward trend are not known, but are evidently independent of the plasma concentration of sex hormones and GH. The increase in IGF-I in response to T treatment despite a moderate decline in GHBP (and possibly GH receptor) levels is most likely due to the large increase in GH, which may override a modest decrease in GHBP/GH receptor.

Adolescent↗
PubMed1996

Multiple fistulas and tracheobronchial stenoses require extensive stenting of the central airways and esophagus in squamous-cell carcinoma.

We report here on two cases of double airway and esophageal stenting in patients with multiple esophagotracheal fistulas and stenoses of the airways and esophagus due to squamous-cell carcinoma. Dumon stents and a Strecker device were used for tracheobronchial stenting. Covered Gianturco Z-stents were implanted into the esophagus. In one case, extrinsic compression of the trachea and tumor progression required recanalization by Nd:YAG laser. Clinical improvement led to discharge of the patients within two weeks after the procedure. The results show that simultaneous implantation of stents in the central airways and covered Gianturco Z-stents in the esophagus is an effective therapeutic strategy in patients with tracheal and esophageal obstructions and esophagorespiratory fistulas. Further systematic studies evaluating double stenting are warranted.

Aged↗
PubMed1996

Prognostic factors for functional outcome of total knee replacement: a prospective study.

BACKGROUND: The objective was to investigate whether baseline physical functioning, medical, psychosocial, or demographic variables predict functional outcome in patients undergoing total knee replacement. METHODS: A prospective cohort study was performed between December 1991 and August 1993. Consecutive, unilateral tricompartmental total knee replacement patients aged > or = 55 yr with osteoarthritis, who met criteria, were enrolled and evaluated one month before and 3 months after total knee replacement. The primary outcome measure was the Medical Outcome Study 36 Item Short Form Health Survey (known as the SF36) Physical Functioning Scale score. The outcome evaluator was not involved in patient care. RESULTS: A hierarchical multiple regression analysis was performed to calculate the contribution of baseline variables to TKR outcome. Of the 27% of outcome variance explained by the model, demographic variables accounted for 4%, psychosocial variables (motivation, role functioning-emotional, and social functioning) for 19% (p = .013), medical variables (previous reconstruction, comorbidity, body mass index, bodily pain) for 2%, and baseline physical function for 2%. CONCLUSIONS: Psychosocial variables are significantly related to total knee replacement functional outcome. Assessment of baseline psychological and social functioning may identify a subset of patients at risk for worse outcome. Specific interventions for these patients should be developed and evaluated as components of patient management prior to and after the procedure.

Activities of Daily Living↗
PubMed1996

Behet's syndrome with pulmonary involvement-combined therapy for endobronchial stenosis using neodym-YAG laser, balloon dilation and immunosuppression.

We present a case report of a patient suffering from Behet's syndrome with pulmonary involvement. The development of endobronchial granulomatosis in the bronchus intermedius and right upper lobe bronchus led to severe bronchial stenosis and dyspnoea. Also aphthous ulcerations in the bronchial mucosa occurred. Treatment of the granulomatous stenosis consisted of Neodym-YAG laser resection and immunosuppression. On follow-up there was a recurrence of the stenosis, characterised by fibrotic strictures. Therefore a balloon dilation was performed and immunosuppression instituted, which led to an increase in airway diameter and a reduction in dyspnoea. These clinical results suggest that recanalisation therapy with Neodym-YAG laser and/or balloon dilation with additional immunosuppression is suitable in benign stenosis (granulomatous or fibrotic), caused by Behet's disease.

Adult↗
PubMed1996

Diagnosis of alveolitis in interstitial lung manifestation in connective tissue diseases: importance of late inspiratory crackles, 67 gallium scan and bronchoalveolar lavage.

The diagnostic relevance of bronchoalveolar lavage (BAL) and associated non-invasive findings in connective tissue diseases (CTD) has not been established regarding alveolitis so far. The goal of the study was to determine the relations between BAL cell differential count and findings of non-invasive diagnostic procedures for alveolitis to predict the clinical value of BAL in CTD. One hundred-five patients (92 non-smokers; 13 smokers) with CTD (73 patients with systemic sclerosis, 19 with systemic lupus erythematosus, 13 with primary Sjögren's syndrome) had symptoms or signs of lung involvement and were further examined (lung function test, chest radiography, thoracic computed tomography, 67 gallium scintigraphy and BAL). The relations between BAL in middle lobe and cell count differentiation to non-invasive investigations were analyzed by logistic regression. In all CTD patients investigated a pulmonal involvement occurred based on non-invasive methods. Regarding non-invasive methods, alveolitis determined by BAL cell differential count was significantly associated with an increased 67-gallium uptake and late inspiratory crackles (P < 0.01), and to a lesser extent with an abnormal interstitial pattern in CT (P < 0.055). Parameters of lung function and laboratory parameters were related to alveolitis using multivariate testing. Considering the alveolitis subtype (granulo- or lymphocytosis), only a reduced FEV1 showed a relationship to granulocytic alveolitis (P < 0.01). Late inspiratory crackles and increased 67 gallium uptake as non-invasive diagnostic findings point out alveolitis in CTD remarkably. Therapeutic and prognostic aspects necessitate BAL to specify the type of alveolitis (lymphocytosis or granulocytosis or mixed forms) in CTD patients with lung manifestation. Non-invasive diagnostic procedures cannot predict the type of alveolitis sufficiently.

Adult↗
PubMed1996

Multifactorial control of the elimination kinetics of unbound (free) growth hormone (GH) in the human: regulation by age, adiposity, renal function, and steady state concentrations of GH in plasma.

To evaluate the principal determinants of the MCR and plasma t1/2 of unbound (free) GH in man, we performed steady state infusions of 3 doses of recombinant human GH during pharmacological suppression (iv octreotide) of endogenous GH secretion in 24 healthy adults and 12 patients (6 adults and 6 children) with chronic renal failure (CRF). Free plasma GH was calculated from total plasma GH (measured by immunoradiometric assay) and GH-binding protein activity (radioligand assay). The MCR of free GH was determined from free plasma GH and the rate of recombinant human GH infusion. The t1/2 of free plasma GH, and the concentration and the in vivo dissociation constant (Kd) of GH-binding protein (GHBP) were estimated by dynamic modeling of the postinfusion total plasma GH concentration decay curves. The MCR of free GH decreased and the plasma GH t1/2 increased significantly with increasing plasma GH concentrations. The MCR of free GH over its physiological concentration range was positively correlated with the body mass index as a measure of relative obesity and negatively related to age, but only at supraphysiological GH concentrations. In the adult patients with CRF, the MCR of free GH was decreased at each infusion rate by 25-38%, and the t1/2 was increased by 80-170%. Children with CRF showed a significantly lower MCR and higher t1/2 of plasma free GH than adult patients. Modeling and direct measurements of the off-rate of GH from its high affinity GHBP indicated normal dissociation rate constants but decreased molar concentrations of the GHBP in uremic plasma. We conclude that the rate of elimination of free GH from plasma in man is controlled by 1) plasma total free GH concentrations, 2) relative obesity, and 3) renal function within the physiological GH concentration range, whereas 4) age is a negative predictor of MCR only at supraphysiological GH concentrations.

Adolescent↗
PubMed1996

Decline of plasma growth hormone binding protein in old age.

Aging is associated with a progressive decline in GH secretion and serum insulin-like growth factor (IGF)-I levels. This change in the GH-IGF axis is thought to contribute to the changes in body composition associated with aging, such as a loss in lean body mass and an increase in adipose tissue mass. Although the decrease in GH secretion starts in the third decade of life, marked changes in muscle mass and strength become apparent only much later. To assess whether a component of GH resistance supervenes in senescence, we studied plasma GH binding protein (GHBP) levels in 50 normal subjects between the ages of 61 and 98 yr. The GHBP is a soluble, circulating ectodomain of the GH receptor (GHR); its plasma level is thought to reflect GHR levels in tissues and, hence, GH responsivity. GHBP activity in plasma declined progressively between age 60 and 98 yr. The GHBP levels in nonagenarians was about half that of persons aged 60-65. This contrasts with younger adults, where GHBP levels remain relatively stable between the ages of 20 and 60. We conclude that in advanced age. GHBP and, by inference, GHR levels, decrease, which may add an element of GH resistance to the already compromised GH secretion status, thereby further contributing to the changes in body composition and frailty in the elderly.

Aged↗
PubMed1996

Insulin, somatotropic, and luteinizing hormone axes in lean and obese women with polycystic ovary syndrome: common and distinct features.

The basic tenet of this investigation was that obesity is not a prerequisite in the development of polycystic ovary syndrome (PCOS), as indicated by the fact that 50% of PCOS women are not obese. Further, obesity itself is a disease entity with the common manifestation of insulin resistance/hyperinsulinemia with PCOS. Given recent evidence that insulin and GH may have gonadotropin-augmenting effects, we have determined the common and distinguishing features of neuroendocrine-metabolic dysfunctions of lean [body mass index (BMI), < 23 kg/m2] and obese (BMI, > 30 kg/m2) women with the classical form of PCOS. Insulin sensitivity, as determined by rapid i.v. glucose tolerance testing; 24-h dynamics of insulin/glucose levels, somatotropic [GH/GH-binding protein/insulin-like growth factor I (IGF-I)/IGF-binding proteins (IGFBP)], and LH axes; and their downstream effects on ovarian steroids were simultaneously assessed in eight lean PCOS and eight obese PCOS patients and an equal number of BMI-matched normal cycling controls. Our results show that insulin sensitivity was reduced 50% (P < 0.01) in lean PCOS from that in lean controls. There was a further decrease in obese controls (P < 0.01) and a 2-fold greater reduction (P < 0.001) in obese PCOS than in obese controls, suggesting that insulin resistance (IR) is a common lesion in PCOS, and that obesity contributes an additional component to IR in obese PCOS. Consistent with the degree of IR, the manifestation of compensatory hyperinsulinemia in lean PCOS was incipient, being evident only in response to meals (P < 0.05), and became overt during the 24-h fasting/feeding phases of the day in obese control (P < 0.001) with a 2- to 3-fold greater elevation (P < 0.001) in obese PCOS. An enhanced early insulin response to glucose occurs equally in obese control (P < 0.01) and obese PCOS (P < 0.05), but not in their lean counterparts. Considering the more profound IR and the associated hyperglycemia in obese PCOS, the magnitude of the early insulin release is inadequate, suggesting that beta-cell dysfunction exists in obese PCOS. Remarkable differences in the somatotropic axis were also observed; although 24-h GH pulse frequency and levels of IGF-I and IGFBP-3 were unaltered by either PCOS or obesity, the 24-h mean GH pulse amplitude was increased by 30% (P < 0.01) in lean PCOS in the presence of normal levels of high affinity GHBP and normal GH response to GHRH. In distinct contrast, the somatotropic axis in both obese control and obese PCOS was profoundly modified, with attenuation of GH pulse amplitude (P < 0.001) and GH response to GHRH (P < 0.001), resulting in a state of hyposomatotropinism with a more than 50% reduction (P < 0.001) of 24-h mean GH levels. In addition, GHBP levels were elevated 2-fold and were correlated inversely with GH (r = -0.81) and positively with insulin (r = 0.75) concentrations. IGFBP-I levels were suppressed in both obese groups, with a 4-fold greater reduction in obese PCOS than that in obese controls. Thus, the downstream effects of hyperinsulinemia on the somatotropic axis may include up-regulation of hepatic production of GHBP, suppression of IGFBP-1 (r = 0.82) and sex hormone-binding globulin (r = -0.69) levels, and a more than 3-fold increase in ratios of IGF-I/IGFBP-1 and estradiol-testosterone/sex hormone-binding globulin, thereby increasing their bioavailabilities. In contrast, LH pulsatility was unaffected by obesity alone. An accelerated LH pulse frequency was evident in both lean and obese PCOS (P < 0.001), whereas the mean 24-h LH pulse amplitude was increased in lean (P < 0.001), but not obese, PCOS patients. These events resulted in a 3-fold increase in 24-h mean LH levels in lean PCOS and a 2-fold increase in obese PCOS. Thus, increased LH pulse frequency and augmented LH response to GnRH are characteristic of PCOS, independent of obesity, and the presence of obesity in PCOS is associated with an attenuated LH pulse amplitude, not accounted f

Adolescent↗
PubMed1996

Detachment of defective septum primum. A potential source of embolism?

Cardiac sources of embolic stroke include various abnormalities of the atrial septum. An atypical detachment of the septum primum was detected in two patients by dynamic three-dimensional echocardiography (DTDE). Between the septum primum and septum secundum a cavity with interatrial communication was detected. Within the cavity a turbulent color Doppler signal and an entry of the contrast agent EchovistR were detected. One of the patients suffered from repeated cerebrovascular events. This unusual defect of the atrial septum may be a potential source of embolism. Transesophageal echocardiography is considered the most sensitive method for the examination of the atrial septum. However, clear anatomic details could only be shown by DTDE.

Adult↗