Search PubMed⌕ Search

Biomedical subjects

J Vogt

Publications and source records attributed to J Vogt.

177 records · Page 10Linked to original sources
PubMedDate not supplied

Simultaneous in utero assessment of AV nodal and ventricular electrophysiologic parameters in the fetal sheep heart.

BACKGROUND: Fetal tachyarrhythmias are usually of supraventricular origin. To investigate whether specific electrophysiologic properties of the fetal heart contribute to this preponderance by either favoring supraventricular tachycardias or by rendering ventricular tachycardias unlikely, we measured fetal electrophysiologic parameters in utero using transuterine fetal transesophageal electrocardiograms in fetal sheep. Since overdrive pacing may help to establish the mechanism of an arrhythmia and may be used to treat fetal tachycardias, different modes of transesophageal pacing in utero were also assessed. METHODS AND RESULTS: Decapolar electrophysiology catheters were fetoscopically inserted into the esophagus of 9 fetal sheep (pregnancy duration 94- 105 days, term = 145 days). Electrocardiograms were recorded simultaneously from all adjacent bipoles and from two pacing wires sutured onto the fetal shoulders. Pacing was attempted either via two adjacent electrodes of the intraesophageal catheter or via the most distal and most proximal electrode. Fetal cycle length, PQ, and QT intervals were close to (approx. 75 %), but fetal QRS duration was < 20 % of maternal values, thus shifting the relation between activation and repolarization towards longer excitation wave lengths. Fetal QT dispersion was small (< or = 10 ms). Atrial pacing was achieved in all fetuses using distant electrodes, and with lower thresholds when compared to closely spaced bipolar electrodes (p < 0.05). CONCLUSIONS: (I) An altered relation between ventricular activation and repolarization and a low dispersion of ventricular repolarization may protect the fetal heart against ventricular reentrant tachycardias. (II) Relatively normal fetal AV nodal conduction delay already provides one of the prerequisites for supraventricular reentrant tachycardias involving the AV node at this stage of fetal development. (III) High-rate esophageal pacing of the fetal atria is best achieved using widely spaced bipolar pacing electrodes.

Animals↗
PubMedDate not supplied

Facial EMG responses to auditory stimuli.

Three studies were performed to investigate the effects of auditory stimuli (pure tones and environmental noise) of different intensities on surface EMG activity recorded over five facial muscle regions (M. frontalis lateralis, M. corrugator supercilii, M. orbicularis oculi, M. zygomaticus major, M. depressor anguli oris). The results show that with presentation of tones and noises of high intensity (> 85 dB) strong facial EMG reactions over muscles of the upper face (M. frontalis lateralis, M. corrugator supercilii, M. orbicularis oculi) were evoked. Among environmental noises of different valence but the same intensity, baby's crying evoked EMG reactions over facial muscles in the mouth region, possibly indicating that the subjects demonstrated expressions of dislike during this particular stimulation. It is also discussed whether facial EMG reactions to auditory stimulation of different intensities could be connected to changes in muscle tone of the middle ear muscles. The contraction of these muscles modulates sensitivity to auditory stimulation. Thus, facial EMG activity of the muscles of the upper face could serve as an indicator of sensitivity to external auditory stimuli. However, the evaluation of pleasant and unpleasant emotional reactions in response to auditory stimulation seems to be impossible.

Acoustic Stimulation↗
PubMedDate not supplied

Reproducibility of quantitative pediatric transesophageal echocardiography.

Transesophageal echocardiography (TEE) is commonly used to monitor cardiac function and to assess cavitary size. For the interpretation of quantitative echocardiographic data, the degree of their reproducibility should be considered. The variability of quantitative TEE was evaluated in this study. To assess intraobserver, beat-to-beat, interobserver, and repositioning variability, TEE examinations of 46 patients with congenital heart defects were analyzed. The mean beat-to-beat variability of 8.5% (range 4.2% to 12.3%) exceeded the mean intraobserver variability of 4.9% (1.9% to 8.1%). The mean interobserver difference between two observers was 3.4% (0.2% to 11.9%). Differences in image acquisition caused by repositioning of the transesophageal probe contributed the most (6.4% to 13.3%; mean 10.5%) to the variability of two-dimensional TEE. Changes seen on TEE studies should be interpreted as abnormal only when they exceed the total variability of this method.

Adolescent↗
PubMedDate not supplied

[Endocardial fibroelastosis of the left ventricle in a patient with Alagille syndrome].

We present a case of a 6 week old infant with Alagille syndrome. Cardiological evaluation revealed peripheral pulmonary arterial stenosis and left ventricular endocardial fibroelastosis. While peripheral pulmonary arterial stenosis are typical for the syndrome this is the first case reported with endocardial fibroelastosis. Complex cardiac malformations may worsen the prognosis in Alagille syndrome. They require early diagnosis and therapy.

Biliary Atresia↗
PubMedDate not supplied

[Acute chorea following heart surgery with hypothermia and total bypass].

We report a 6 year old girl who developed acute chorea following cardiac surgery using hypothermia and total cardiopulmonary bypass. Rheumatic disease, cerebral embolism or hemorrhage were excluded. Cerebral hypoperfusion during surgery is the most probable cause for this neurologic event. Treatment with Tiaprid (Tiapridex) resulted in a rapid resolution of symptoms.

Brain Ischemia↗
PubMedDate not supplied

[Surgical treatment of congenital abnormalities of the right heart].

The surgical treatment of complex congenital malformations of the right heart is described and discussed with regard to the following heart diseases: tetralogy of Fallot (FT), transposition of the great arteries (TGA), tricuspid atresia (TA), single ventricle (SV). The results of the patient material of Goettingen were focused on the right ventricular function. With reference of the FT-correction a residue pulmonary stenosis is considered to be better tolerated than a residual pulmonary insufficiency. The long-term results (observation time from 4 to 17,5 years) proved that the right ventricle (RV)-function can adapt itself to pressure load. Adequate growth to the hypoplastic right ventricle is documented due to right ventricular volume load after operative repair. The Fontan procedure for TA and SV has revealed that the inactivation of the right ventricular pumpunction has not resulted in negative effect on the function of the systemic ventricle, patients clinical conditions and exercise testing have improved.

Adolescent↗
PubMedDate not supplied

[Value of 2-dimensional echocardiography in the diagnosis of infectious endocarditis].

Cross sectional and simultaneous M-mode echocardiograms were performed on 15 consecutive patients with infective endocarditis, 14 of whom had pre-existing cardiac lesions. Patients were divided into two groups based on the presence or absence of echocardiographically detected vegetative lesions. In 10 out of 15 patients vegetations were present (66%): aortic valve 5, mitral valve 1, tricuspid valve 1, both aortic and mitral valves 1 and left ventricular endocardium associated with aortic valve lesion 2. In this group 3 had systemic embolic episodes and 2 died, whereas none of the 5 patients without detectable vegetations had complications. In 6 the preoperative echocardiographic findings could be confirmed at surgery or autopsy. Emergency surgery without catheterization was performed in 2 patients. Two dimensional echocardiography provides an important non invasive method of assessing a significant percentage of vegetations, but a negative echocardiogram does not exclude infective endocarditis. From the present experience and that of others the detection of vegetations by echocardiography identifies a subgroup of patients with a higher risk for complications in whom early operative intervention without catheterization can be performed. Cross sectional echocardiography may also prove helpful for serial examination of valve vegetations.

Adolescent↗
PubMedDate not supplied

[A rare combination of partial trisomy 9 with pulmonary atresia].

We report of an previously unpublished combination of partial trisomy 9 and a membranous pulmonary atresia with a large conotruncal ventricular septal defect. The dystrophic female, term newborn presented after delivery with microcephaly, prominent nose and several other facial and skeletal deformities. The echocardiography and angiography showed a membranous pulmonary atresia with ventricular septal defect. Chromosomal analysis revealed a partial trisomy of the short arm with parts of the long arm of chromosome 9 and a small part of the long arm of chromosome 4. A surgical repair of the heart defect was not performed by the known high risk of severe mental retardation of partial trisomy 9. The child died at the age of six months.

Abnormalities, Multiple↗
PubMedDate not supplied

Complaint data as an index of annoyance--theoretical and methodological issues.

Complaining constitutes one facet of all reactions to noise annoyance and is one way to cope with annoyance due to aircraft noise. In order to value and to establish the usefulness of complaint data as an index of annoyance, four questions need to be answered: Which factors lead annoyed residents to complain about aircraft noise or related issues? Which factors keep annoyed residents from complaining? Are the existing ways to handle annoyance adequate and efficient (e.g. keeping track of complaints, reaction to complains, kinds of complaint services)? Which are new ways to handle annoyance adequately and efficiently? In this paper a first attempt to answer these questions is made. Obviously, complaint data do not reflect noise annoyance in the surroundings of airports to the full extent as there are residents living in affected areas who do not complain, as well as residents living in areas with relatively low noise levels who complain. Also there is a large group of people who declare to be highly annoyed and yet, they do not lodge any complaint. Possible intervening factors are gathered that determine if an annoyed resident takes action and complains. It was found that noise levels per se are not the crucial factor for residents' decisions to complain or not to complain. Personal as well as feasibility factors play a vital role. Yet, the ongoing controversy on the relation between annoyance and complaint behaviour seems not resolved yet. However, complaint behaviour seems to be influenced by various aspects and complaint data consequently cannot be accepted as an accurate measure of public annoyance. Further research is required to address the preferred method of handling reaction to noise and the extent to which complaint itself helps with coping, for different groups of residents.

Adaptation, Psychological↗
PubMedDate not supplied

Cell analysis with the new Leipzig high-energy ion nanoprobe.

The high-energy ion nanoprobe LIPSION at the University of Leipzig has been in operation since 1998. The ultrastable, 3.5 MV SINLETRON accelerator supplies the H+ or He+ ion beam. A magnetic scanning system moves the focused beam across the sample. At present, a resolution of 41 +/- 4 nm in the low current mode and 300 nm at 5 pA can be achieved. The experimental chamber is equipped with electron-, energy dispersive X-ray-, and particle detectors. They can be used simultaneously to analyse the sample by means of PIXE (particle induced X-ray emission), RBS (Rutherford backscattering), and in the case of thin sections or monolayer samples STIM (scanning transmission ion microscopy). A goniometer allows the application of channeling measurements in single crystals in combination with these methods. In contrast to previous publication describing microbeam facility at LIPSION, the current biomedical research has concentrated on microscopy and tomography on chondrocytes in pig cartilages and fixed single endothelial cells (HUVEC). For the irradiation of single living cells, an external beam facility with irradiation platform, fast beamgate and mini-Petri dishes is under construction.

Animals↗
PubMedDate not supplied

Ineffectiveness of nickel in augmenting the hepatotoxicity in protein deficient rats.

This study was designed to determine the toxic effects of nickel sulfate on the biochemical and elemental profile of liver in protein deficient rats. Nickel sulfate in the dose of 800mg/l in drinking water was administrated to Sprauge Dawley (S.D) normal control as well as protein deficient rats for a total duration of eight weeks. The effects of nickel treatment and protein deficiency when given separately and in combination were studied on rat liver marker enzymes like Alkaline phosphatase (ALP),Glutamate oxaloacetate transaminase (GOT), Glutamate pyruvate transaminase (GPT) and also on the status of essential elements in rat liver. Protein deficient, Ni treated as well as combined protein deficient and nickel treated rats showed significant reductions in the body weight and hepatic protein contents as compared to normal control rats. Hepatic alkaline phosphatase activity and alanine aminotransferase showed a significant elevation in rats subjected to protein deficiency, nickel treatment and combined protein deficiency and nickel treatment. As regards to hepatic levels of aspartate aminotransferase a significant elevation was observed in protein deficient and nickel treated protein deficient animals. Nickel administration to normal and protein deficient rats has resulted in a significant increase in concentrations of nickel, phosphorus and sulfur in liver tissue. The concentration of zinc and copper in liver tissue decreased significantly in protein deficient, nickel treated and nickel treated protein deficient animals. Tissue iron concentrations were found to be decreased in protein deficient animals, but the concentrations of iron got elevated significantly in nickel treated and nickel treated protein deficient animals. It has been observed that selenium got decreased significantly in protein deficient, nickel treated and nickel treated protein deficient animals when compared to normal animals. The elevation of selenium in nickel treated protein deficient animals was also significantly higher when compared to protein deficient animals.

Animals↗
PubMedDate not supplied

The durability of bioprostheses in young people. Long-term results with intra- or extracardiac implanted porcine valves.

Forty two children and two young adults who were long term survivors of either intracardiac or extracardiac valve replacement with glutaraldehyde porcine valves form the basis of this report. The follow-up period varied from 6 months to 9 years. Ten of eleven intracardiac valves developed some dysfunction--the eleventh patient died from other causes. Of a total of 36 extracardiac valved conduits in the Rt side of the heart, four have needed replacement and an additional four will require replacement in due course. The probability of an event free performance of an intracardiac porcine valve is zero at 5 years. Four extracardiac valves there is in an 80% expectancy at 5 years and a 12% at 8 years of trouble free existence.

Adolescent↗
PubMedDate not supplied

Aortoventriculoplasty for different types of left ventricular outflow tract obstructions.

Since the first clinical application of aortoventriculoplasty for tunnel subaortic stenosis in 1974 the indication for this method was extended to other types of left ventricular outflow tract stenoses (LVOTO). The operative technique consists of enlarging both the left and right ventricular outflow tracts and inserting an aortic prosthetic valve. 47 operations have been performed in patients with various types of LVOTO: 8 narrow annulus, 23 diffuse subaortic stenosis (multiple level stenosis), 9 complex forms of tunnel subaortic stenosis (Shone complex) 3 outgrown prosthesis, 4 obstructive idiopathic hypertrophic subaortic stenosis. Patients ages ranged from 4 to 35 years. Overall mortality was 13%, there were no late deaths, in the last 34 patients there was no death. In 25 patients there had been 1, and in 13 patients 2 previous procedures. As a result of the operation 9 patients developed complete right bundle branch block or left anterior hemi-block; 2 patients developed total a-v block with the need of a permanent pacemaker 25 patients had catheterization postoperatively. The mean gradient across the left ventricular outflow tract was significantly reduced from 91.5 +/- 21 mm Hg to 13.1 +/- 15 mm Hg. According to our experience aortoventriculoplasty can be used routinely in all forms of diffuse subaortic stenosis, narrow aortic annulus, reoperation in HOCM, multiple level stenosis and outgrown aortic prosthesis.

Adolescent↗
PubMedDate not supplied

[Treatment of spastic equinovarus deformity. Apropos of 60 operations].

The authors evaluate the efficiency of the surgical technique of split anterior tibialis transfer, describe the long term functional results of the operation, and discuss the indications of this method of treatment. The results were very satisfactory: after surgery, 46 of 53 patients had normal shoes, 33 patients had improvement of their level of autonomy. The morbidity was very low, no patient had aggravation of the neurologic disease or general complications. The authors conclude that this operation should be employed more frequently in these disabled patients who can find definite improvement.

Adolescent↗