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Biomedical subjects

M Vogel

Publications and source records attributed to M Vogel.

At least 109 records · Page 6Linked to original sources
PubMed2000

The South Asian cataract management study: complications, vision outcomes, and corneal endothelial cell loss in a randomized multicenter clinical trial comparing intracapsular cataract extraction with and without anterior chamber intraocular lens implantation.

OBJECTIVE: To determine clinical outcomes of primary intracapsular cataract surgery with and without implantation of anterior chamber lenses. DESIGN: A multicenter randomized clinical trial. PARTICIPANTS: One thousand two hundred twenty-nine male and female patients 40-75 years of age with senile cataract. METHODS: Study patients were recruited from screening eye camps and outpatient clinics. Randomization to the two treatment groups was performed after screening for predetermined inclusion and exclusion criteria. Demographics, visual acuity, intraocular pressures, and corneal endothelial cell data were recorded before surgery and at 6 weeks, 12 months, and 24 months after surgery. Monitoring of the study was secured by a standardized image documentation procedure on all patients using the IMAGEnet digital imaging system. Analysis of corneal endothelial cell images was performed with the Cell Soft software (Topcon Corporation, Japan). MAIN OUTCOME MEASURES: Visual acuity and central corneal endothelial cell loss. RESULTS: The patients were randomized to intraocular lens (IOL; n = 616) and no IOL (n = 613) implantation. Surgical complications were reported in 177 (14.4%) patients (IOL = 14.8%; no IOL = 14.0%). The most frequent complication observed was vitreous loss which occurred in 10.3% of eyes (IOL = 11.2%; no IOL = 9.5%). At the final examination (2 years after surgery), 88% of the operated eyes had a best corrected vision of 6/18 or better (IOL = 88.8%; no IOL = 86.6%). Analysis of corneal endothelial cell data showed a small but significantly greater cell loss 6 weeks after surgery in eyes with IOL compared with those without IOL, but no overall difference was found between the treatment groups in the long term follow-up. CONCLUSIONS: The findings indicate that there is a rationale for the use of anterior chamber intraocular lenses in primary intracapsular cataract surgery.

Adult↗
PubMed2000

Perinatal differential diagnosis of cystic kidney disease and urinary tract obstruction: anatomic pathologic, ultrasonographic and genetic findings.

According to the classification of Osathanondh and Potter of cystic kidney diseases an antenatal differential diagnosis is presented, which is based on the anatomic pathologic, ultrasonographic and genetic findings. Since the ultrasound evaluation influences the obstetric and neonatal management, each second and third trimester sonography should consider the most common malformations in pediatric autopsies. The autosomal recessive polycystic kidney disease (ARPK), autosomal dominant polycystic kidney disease (ADPK), multicystic renal dysplasia, obstructive multicystic kidneys and cystic renal malformations found in other syndromes with genetic linkage are discussed in this review.

Diagnosis, Differential↗
PubMed2000

Cyanotic nephropathy and use of non-ionic contrast agents during cardiac catherization in patients with cyanotic congenital heart disease.

BACKGROUND: Chronic cyanosis with its associated rheologic changes is a known risk factor for glomerular nephropathy. Therefore, contrast-induced nephrotoxicity should be an important consideration for angiographers comparable to diabetics. On the other hand, progressions in diagnostic and interventional techniques have led to expanded indications and a more widespread use of x-ray contrast agents. The aim of this study was to investigate the risk of contrast-induced nephropathy in the small group of patients with cyanotic heart disease prior to surgical repair. METHODS: We investigated 23 cyanotic patients with an oxygen saturation of 82 (50-92)%, age 25 (5-63) years, and 13 control subjects with atrial septal defect, age 37 (20-66) years. Blood viscosity was measured before and after cardiac catherization. Renal damage was evaluated by selective analysis of urinary proteins and enzymes. RESULTS: Before cardiac catheterization, 48% of the cyanotic patients had a moderate glomerulopathy. Cardiac catherization was performed with 3.0 (1.2-6.8) mls/kg non ionic contrast medium. Only one of the 23 patients (4.3%) with normal urinary analysis before cardiac catheterization showed renal damage, which involved tubular and glomerular function. Elevated blood viscosity in cyanotic patients was slightly reduced by the contrast. None of the acyanotic controls had contrast-induced nephropathy. CONCLUSIONS: The use of non-ionic contrast medium does not worsen cyanotic glomerulopathy. This finding may be due to the reduction of blood viscosity by the application of the contrast medium. The finding of contrast-induced nephropathy in one patient underlines the importance of monitoring renal function after cardiac catheterization.

Adolescent↗
PubMed2000

Treatment of atrial septal defects in symptomatic children aged less than 2 years of age using the Amplatzer septal occluder.

AIMS: To assess results of closure of atrial septal defects within the oval fossa by devices delivered by catheterisation in symptomatic infants and children under 2 years of age. METHODS AND RESULTS: The Amplatzer septal occluder was used. Results, and complications of transcatheter device treatment in patients aged below 2 years were compared to previous results from our institution. PATIENTS: We attempted closure in 12 consecutive patients below the age of 2 years who presented with an atrial septal defect between May 1997 and 1999. Symptoms were failure to thrive in 6, frequent chest infections in 5, and the need for treatment of heart failure in the other. All were thought to have a defect suitable for interventional closure. The atrial defects were seen in isolation in 10 children, but 2 had associated pulmonary stenosis which had been treated by balloon dilation prior to placement of the Amplatzer occluder. RESULTS: The Amplatzer septal occluder was implanted at a mean age of 1.4 +/- 0.4, with a range from 0.8 to 1.8 years. Ratios of pulmonary-to-systemic flow had been 2.1 +/- 0.5, with a range from 1.6 and 3.2, and the defect was measured at 12 +/- 4 mms. Fluoroscopy time was 12.8 +/- 10.2 minutes, with a range from 5 to 43 minutes, and the time of the overall procedure was 162 +/- 70 minutes, with a range from 85 to 360 minutes. It proved necessary to remove the device in 2 patients (16%) because of a residual shunt and movement after release. One of these developed transient neurological complications. Both subsequently underwent surgical treatment. CONCLUSION: Symptomatic patients less than 2 years of age can undergo successful closure of an atrial septal defect using the Amplatzer device, but the rates of success are less, and procedure time longer, than in older children or adults.

Cardiac Catheterization↗
PubMed2000

Transthoracic three-dimensional echocardiography for the assessment of straddling tricuspid or mitral valves.

BACKGROUND: The advent of 3D echocardiography has provided a technique which, potentially, could afford significant additional information over conventional cross-sectional echocardiography in the assessment of patients with straddling atrioventricular valves prior to surgical correction. METHODS: Eight patients, aged from 1 month to 9.2 years, were examined with 3D echocardiography. All but three had discordant ventriculoarterial connections or double outlet right ventricle. Data suitable for reconstruction was acquired with transthoracic scanning. Right and left ventricular volumes were calculated in the 3D dataset. RESULTS: 3D echocardiography proved capable of defining the exact degree of straddling by imaging the proportion of tension apparatus attached to either side of the ventricular septum. It was able also to display the atrioventricular junction "en face", thus permitting identification of the precise site of insertion of the muscular ventricular septum relative to the atrioventricular junction. This made it possible first, to calculate the degree of valvar override, and second, to predict the location of the penetrating atrioventricular bundle. End-diastolic volume of the right ventricle in those with straddling tricuspid valves was 73 (61-83)% of normal, and, of the left ventricle in those with mitral valvar straddling 71 (40-97)% of normal. CONCLUSIONS: 3D echocardiography can aid in planning the optimal surgical procedure in patients with straddling or overrriding atrioventricular valves, as it provides diagnostic information superior to standard cross-sectional techniques. It also allows for exact measurement of the volumes of the respective ventricles.

Child↗
PubMed2000

Clinical variability of Larsen syndrome: diagnosis in a father after sonographic detection of a severely affected fetus.

Larsen syndrome shows a broad spectrum of clinical manifestation ranging from a lethal form of the disorder to a mild clinical expression with absence of major diagnostic features. Here we show that even intrafamilial manifestation may vary extremely to the point that Larsen syndrome in a father has been diagnosed only by typical sonographic features in an affected fetus.

Adult↗
PubMed2000

CHO expression of a novel human recombinant IgG1 anti-RhD antibody isolated by phage display.

Replacement of the hyperimmune anti-Rhesus (Rh) D immunoglobulin, currently used to prevent haemolytic disease of the newborn, by fully recombinant human anti-RhD antibodies would solve the current logistic problems associated with supply and demand. The combination of phage display repertoire cloning with precise selection procedures enables isolation of specific genes that can then be inserted into mammalian expression systems allowing production of large quantities of recombinant human proteins. With the aim of selecting high-affinity anti-RhD antibodies, two human Fab libraries were constructed from a hyperimmune donor. Use of a new phage panning procedure involving bromelin-treated red blood cells enabled the isolation of two high-affinity Fab-expressing phage clones. LD-6-3 and LD-6-33, specific for RhD. These showed a novel reaction pattern by recognizing the D variants D(III), D(IVa), D(IVb), D(Va), D(VI) types I and II. D(VII), Rh33 and DFR. Full-length immunoglobulin molecules were constructed by cloning the variable regions into expression vectors containing genomic DNA encoding the immunoglobulin constant regions. We describe the first, stable, suspension growth-adapted Chinese hamster ovary (CHO) cell line producing a high affinity recombinant human IgG1 anti-RhD antibody adapted to pilot-scale production. Evaluation of the Fc region of this recombinant antibody by either chemiluminescence or antibody-dependent cell cytotoxicity (ADCC) assays demonstrated macrophage activation and lysis of red blood cells by human lymphocytes. A consistent source of recombinant human anti-RhD immunoglobulin produced by CHO cells is expected to meet the stringent safety and regulatory requirements for prophylactic application.

Animals↗
PubMed2000

Adrenal tissue in the placenta: a heterotopia caused by migration and embolism?

Heterotopic adrenal tissue is not uncommon, especially in the urogenital system. Adrenocortical tissue in the placenta, however, is presumably very rare. To our knowledge, four cases have been published. There are several different theories to explain such a heterotopia. According to our findings, an embolic spread of adrenal precursor cells via fetal vascular shortcuts is the most likely mechanism. Apart from that hypothesis, the possibility of a monodermal teratoma as well as of an aberrant differentiation of cells of the extraembryonic mesoderm are considered in the literature.

Adrenal Glands↗
PubMed2000

Phase behavior of a mixture of platelike colloids and nonadsorbing polymer

Suspensions of sterically stabilized colloidal gibbsite platelets have recently been found to exhibit both an isotropic-nematic (I-N) and a nematic-columnar (N-C) phase transition. In the present paper we show that depletion attraction, brought about by the addition of nonadsorbing polymer, enriches the phase behavior of these platelet suspensions even further. Pronounced broadening of the isotropic-nematic gap occurs, with purely nematic samples re-entering the biphasic state by the addition of nonadsorbing polymer. At the same time, depletion attraction enhances size fractionation between coexisting phases, which actually provides an effective means for reducing the polydispersity of the suspensions. An additional isotropic phase emerges, which leads to the appearance of several three-phase equilibria and even a four-phase equilibrium. We explain the observed topology of the phase diagram by the interplay between depletion attraction and the platelets' polydispersity.

Journal Article↗
PubMed2000

Feasibility of brain volumetric analysis and reconstruction of images by transfontanel three-dimensional ultrasound.

Based on the authors' experience with reconstruction of the heart using three-dimensional echocardiography, the authors assessed the feasibility of three-dimensional reconstruction of brain images using transfontanelle ultrasound in selected cases of infants with abnormal intracranial findings. A conventional 5-MHz ultrasound transducer inside a transducer holder was rotated 180 degrees around its vertical axis using a computer-controlled stepper motor to acquire multiple sequential cross-sections of the brain. The raw digital data of this three-dimensionally recorded dataset were transferred to a PC-based workstation for further analysis. The reconstruction of the three-dimensional brain images and volumetric analysis were undertaken using a new dedicated software capable of three-dimensional reconstruction and volumetric analysis (Echo-PAC-3D, version 1.2 Beta, GE Vingmed, Horton, Norway). The reconstruction of sequential slices from the stored three-dimensional data allowed the visualization of the epicortical extension and volumetric measurements of the focal ischemic infarction in the superior tempoparietal lobe in a 2-week-old newborn with a focal ischemic brain lesion. In other 2-week-old newborns, the extension and volume of a periventricular hemorrhage was visualized by three-dimensional reconstruction of coronal cross-sectional images from the acquired three-dimensional dataset. The three-dimensional reconstruction of the lateral ventricles allowed the three-dimensional visualization and estimation of ventricular dilatation in milliliters in an 8-week-old infant with hydrocephalus. Three-dimensional reconstruction of brain images and volume estimation of brain lesions and cavities by ultrasound may provide new insights into the morphology and extension of ultrasonographically visible brain lesions.

Brain↗
PubMed2000

Morphology of perforated atrial septal aneurysm suitable for closure by transcatheter device placement.

OBJECTIVE: To define the morphological criteria of perforated atrial septal aneurysms suitable for closure by a transcatheter device. METHODS: A retrospective analysis of all consecutive patients with atrial septal aneurysm and one or more perforations presenting between May 1997 and June 1999. The aneurysms were classified as: aneurysm with persistent foramen ovale (type A); aneurysm with single atrial septal defect (type B); aneurysm with two perforations requiring more than one device for closure (type C); and aneurysm with multiple perforations (type D). PATIENTS: Data from 50 patients aged 5-78 years (mean 43 years) were analysed; 32 had systemic thromboembolism or transient ischaemic attacks, eight presented with dyspnoea on exercise, and 10 were discovered incidentally but had significant left to right shunt and right ventricular volume overload. RESULTS: In all 18 patients with aneurysm and persistent foramen ovale (type A), transcatheter closure was possible. In nine with aneurysm and atrial septal defect (type B), five defects were closed and four required surgery. Device closure was achieved in all 10 patients with aneurysms and two perforations (type C), but four had a residual shunt. Thirteen patients with multiple perforated aneurysms (type D) underwent surgery. CONCLUSIONS: This classification of morphology of perforations of aneurysm is clinically useful for selecting patients for treatment by transcatheter devices.

Adolescent↗
PubMed2000

Relation between right ventricular enlargement, QRS duration, and right ventricular function in patients with tetralogy of Fallot and pulmonary regurgitation after surgical repair.

OBJECTIVE: In patients with repaired tetralogy of Fallot, to examine (1) a possible relation between right ventricular enlargement and QRS prolongation, and (2) the effect of right ventricular enlargement caused by pulmonary regurgitation on the right ventricular ejection fraction, evaluated by three dimensional echocardiography, and global function, evaluated by the myocardial performance index. DESIGN AND PATIENTS: 40 patients with repaired tetralogy were studied. Right ventricular volumes were derived from three dimensional echocardiographic data after this method had been validated by comparison with magnetic resonance imaging in 21 patients. Ejection fraction was calculated from end diastolic and end systolic volumes. The Doppler derived myocardial performance index was measured in all patients. Measured data were correlated with QRS duration. SETTING: Tertiary cardiac centre for congenital heart disease. RESULTS: There was good agreement between three dimensional echocardiographic and magnetic resonance assessment of right ventricular volumes and ejection fraction. The z score of the right ventricular end diastolic volume and ejection fraction of all patients was 1.35 and -4.15, respectively. Patients with severe pulmonary regurgitation had a lower right ventricular ejection fraction (p < 0.01) and an increased myocardial performance index (p < 0.01) compared with patients with mild to moderate pulmonary regurgitation. The correlation between ejection fraction and right ventricular end diastolic volume was r = -0.35 (p < 0.05). The mean (SD) QRS duration was 131.89 (25.69) ms, range 80-180 ms. The correlation between QRS duration and right ventricular end diastolic volume was r = 0.6 (p < 0.01). CONCLUSIONS: There is a correlation between the right ventricular size obtained by three dimensional echocardiography and QRS duration on the surface ECG, indicating mechanoelectrical interaction. The severity of pulmonary regurgitation has a negative influence on right ventricular ejection fraction and combined systolic and diastolic global function, as assessed by myocardial performance.

Adolescent↗
PubMed2000

Arterial switch procedure for D-transposition of the great arteries: quantitative midterm evaluation of hemodynamic changes with cine MR imaging and phase-shift velocity mapping-initial experience.

PURPOSE: To evaluate cine magnetic resonance (MR) imaging and phase-shift velocity mapping for assessment of the hemodynamic relevance of stenotic segments or specific hemodynamic changes in the great vessels after an arterial switch procedure for correction of D-transposition of the great arteries. MATERIALS AND METHODS: Twenty consecutive patients (age range, 2-17 years) with an acoustic window that was insufficient for Doppler transthoracic echocardiography were included in the study. Flow and diameter measurements of the pulmonary arterial trunk and its primary branches were performed with phase-shift velocity mapping and cine MR imaging. RESULTS: There were good correlations between pressure gradients in the pulmonary arteries estimated with MR imaging and those measured with Doppler echocardiography (r = 0.83, n = 15) and cardiac catheterization (r = 0.90, n = 13). Cine MR imaging revealed that the diameters of the right and left pulmonary arteries decreased with the expansion of the aorta during systole, which increased the peak velocity. This temporary stenosis was more severe in the right than in the left pulmonary artery and was accompanied by a significantly (P <.05) lower volume flow in the right artery. CONCLUSION: The anatomic situation after arterial switch repair tended to produce temporary stenoses in the primary pulmonary arterial branches, with significant changes in hemodynamics. These changes may affect the long-term outcome and go undetected with other imaging modalities.

Adolescent↗
PubMed2000

Diagnosis of congenital heart malformations--possibilities for the employment of telepathology.

GOAL: In a study of 10 autopsy cases with congenital cardiac malformations we investigated whether obtaining a second opinion by means of telepathology could satisfy quality standards for the diagnosis of cardiac malformations and what the advantages and disadvantages of such a procedure might be. MATERIAL: The investigatory samples were 10 formalin-fixed hearts with complex malformations from 9 fetuses and one newborn on which autopsies had been performed at the Pathological Institute of the Charité Hospital. The requests for a second opinion, which included text and image data, were sent in the form of Microsoft PowerPoint presentations to 5 experts in 4 countries. Per case the number of images that were sent was between 3 and 7. The size of the files was between 439 and 942 kb. The time required for preparation of the cases for sending them to the specialists was between 1 and 2 hours: this encompassed the time for putting the notation on the images, compressing them, creating a file that included both the images and the clinical data and then sending the case file. RESULTS: All 10 cardiac malformations were correctly identified. In 8 of the 10 cases at least one expert had questions. After these questions had been answered and further images had been sent final correct diagnoses were made in all cases. All experts said that the quality of the images was very good. Use of a standardized findings questionnaire, which also included the marking of anatomic structures and of pathological findings in the images, proved useful. Standardized findings forms facilitate orientation during interpretation of the cases and should be used generally to avoid misunderstandings in telepathological communication. CONCLUSIONS: In general it is possible to obtain an effective and reliable diagnosis of congenital heart malformations by means of telepathology. It is far quicker to get a second opinion by this means than by conventional means.

Autopsy↗
PubMed2000

Independent confirmation of a major locus for obesity on chromosome 10.

Linkage results obtained in genome-wide scans for complex phenotypes require confirmation in independent samples. Recently, linkage of obesity to chromosome 10p12 with a maximal multipoint LOD score of 4.85 was reported upon use of an affected sib-pair approach including nuclear families in which the adult index case had a BMI > or = 40 kg/m2 and at least one further sibling had a BMI > or = 27 kg/m2 (Hager et al., 1998, Nat Genet 20:304-8). To attempt to replicate this linkage finding we genotyped 11 markers spanning approximately 23 cM from 10p13 to 10ql1 in a total of 386 individuals stemming from 93 nuclear families with two or more young obese offspring with a BMI > or = 90th age percentile. The highest multipoint maximum likelihood binomial (MLB) LOD score using the extreme concordant sib-pair approach in which one sib had a BMI > or = 95th percentile, and other sibs a BMI > or = 90th percentile was 2.32. Six markers yielded nominal p-values < 0.05, the highest two point MLB-LOD score of 2.45 (nominal p = 0.0004) was obtained for the marker TCF8. Transmission disequilibrium tests for the most frequent parental allele yielded no nominal p-value < 0.05. The linkage results confirm the presence of a major susceptibility locus for obesity in a region near the centromere on chromosome 10.

Adult↗
PubMed2000

Il-1 beta, Il-6, Il-8 and G-CSF in the diagnosis of early-onset neonatal infections.

OBJECTIVE: To determine whether inflammatory cytokine concentrations (Il-1 beta, Il-6, Il-8 and G-CSF) in umbilical cord blood are useful predictors of an early-onset neonatal infection. MATERIAL AND METHODS: 240 women and their newborns were enrolled in our study and umbilical cord blood samples collected from neonates (n = 240) were subjected to ELISA for Il-1 beta, Il-6, Il-8 and G-CSF. Clinical outcome of the neonates was followed and documented. Placenta histology was also available in majority of the cases (n = 195). RESULTS: Early-onset neonatal infection was diagnosed in 5.4% of neonates (13/240) and placental examination showed histologic chorioamnionitis in 17.9% (35/195). Both Il-1 beta and Il-6 cord blood concentrations were elevated in association with histologic chorioamnionitis (Il-1 beta-2.7 vs. 2.1 pg/ml, p < 0.05 and Il-6 15.6 vs. 12.8 pg/ml, p < 0.005). Only Il-6 was elevated (16.0 vs. 13.2 pg/ml, p < 0.05) in neonates with early-onset bacterial infections. ROC analysis showed acceptable diagnostic performance of Il-6 in the identification of acute histologic chorioamnionitis and clinical neonatal infection. CONCLUSION: Il-6 in umbilical cord blood seems to be a promising predictor for early-onset neonatal infections.

Chorioamnionitis↗