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Biomedical subjects

H Baumgartner

Publications and source records attributed to H Baumgartner.

At least 73 records · Page 4Linked to original sources
PubMed1991

[The upper cervical spine. Symptomatology, clinical diagnosis and therapy of functional disorder].

Due to the closely related trigeminus nuclei, segmental functional disorders in the suboccipital area cause--in addition to local neck pain--frontoparietal and retro-orbital pain that can also irradiate to the upper and lower jaw. In addition, tendomyoses with trigger points and difficulties in swallowing may occur in the anterior part of the neck. In order to differentiate between hypomobility, hypermobility or instability, clinical diagnostics requires specific examination of each particular segment in accordance with its biomechanics. Once the nature of the functional disorder is defined, the whole repertoire of therapeutic measures can be applied, with segment-oriented manual techniques being the most efficient. In cases of persisting and recurrent disturbances, rehabilitation must be completed by regular back exercises and optimal ergonomics.

Cervical Vertebrae↗
PubMed1990

Determination of aortic valve area by Doppler echocardiography using the continuity equation: a critical evaluation.

In 35 patients with aortic stenosis the Doppler-derived values of the aortic valve area (continuity equation) were compared with those determined at cardiac catheterization (Gorlin's formula). The comparison of three modifications of the continuity equation showed that the procedure generally proposed (calculating the area of the left ventricular outflow tract from its diameter) significantly underestimated the valve area (modification 1). Modification 2, which used direct planimetry of the left ventricular outflow tract, yielded results quite consistent with invasive measurements. The employment of peak velocities instead of velocity-time integrals (modification 3) did not significantly alter the results. However, the scatter was considerable in all three modifications. When critical aortic stenosis was defined with a valve area less than or equal to 0.70 cm2, modifications 1, 2, and 3 accurately predicted the severity of stenosis in 80, 86, and 80%, respectively.

Aortic Valve↗
PubMed1990

Discrepancies between Doppler and catheter gradients in aortic prosthetic valves in vitro. A manifestation of localized gradients and pressure recovery.

To evaluate possible causes of discrepancy between Doppler and catheter gradients across prosthetic valves, five sizes (19-27 mm) of St. Jude and Hancock valves were studied in an aortic pulsatile flow model. Catheter gradients at multiple sites distal to the valve were compared with simultaneously obtained Doppler gradients. In the St. Jude valve, significant differences between Doppler and catheter gradients measured 30 mm downstream from the valve were found: Doppler gradients exceeded peak catheter gradients of 10 mm Hg or more by 81 +/- 35% (15 +/- 3.6 mm Hg), and mean catheter gradients by 71 +/- 11% (10.3 +/- 2.5 mm Hg). When the catheter was pulled back through the tunnel-like central orifice of the valve, high localized gradients at the valve plane and significant early pressure recovery were found. When the catheter was pulled back through the large side orifices, gradients at the same level were only 46 +/- 6% of the central orifice gradients (mean difference, 7.6 +/- 4.5 mm Hg). Doppler peak and mean gradients showed excellent agreement with the highest central orifice catheter gradients (mean difference, 1.0 +/- 3.1 and 0.9 +/- 1.5 mm Hg, respectively). A significantly better agreement between Doppler and catheter gradients at 30 mm was found for the Hancock valve, although Doppler peak and mean gradients were still slightly greater than catheter gradients. Doppler gradients exceeded catheter gradients by 18 +/- 10% (3.4 +/- 1.9 mm Hg) and 13 +/- 11% (2.1 +/- 0.9 mm Hg), respectively. When the catheter was pulled back through the valve, the highest gradients were found approximately 20 mm distal to the valve ring.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Carbocyclic 5-iodo-2'-deoxyuridine (C-IDU) and carbocyclic (E)-5-(2-bromovinyl)-2'-deoxyuridine (C-BVDU) as unique examples of chiral molecules where the two enantiomeric forms are biologically active: interaction of the (+)- and (-)-enantiomers of C-IDU and C-BVDU with the thymidine kinase of herpes simplex virus type 1.

The (+)- and (-)-enantiomers of the carbocyclic analogues of (E)-5-(2-bromovinyl)-2'-deoxyuridine (C-BVDU) and 5-iodo-2'-deoxyuridine (C-IDU) were synthesized by separate routes. Both the (+)- and (-)-enantiomers of C-BVDU and C-IDU were markedly inhibitory to herpes simplex virus type 1 (HSV-1) replication. (+)-C-BVDU and (+)-C-IDU were as inhibitory to HSV-1 as the racemic (+/-)-C-BVDU and (+/-)-C-IDU, respectively, whereas the (-)-enantiomers were only 10-fold less active. Also, the (+)- and (-)-enantiomers of C-BVDU were equally inhibitory to the growth of murine mammary carcinoma cells transformed by the HSV-1 or HSV-2 thymidine kinase (TK) gene (designated FM3A TK-/HSV-1 TK+ and FM3A TK-/HSV-2 TK+). The (+)- and (-)-enantiomers of C-BVDU and the (+)- and (-)-enantiomers of C-IDU had a remarkably similar affinity for HSV-1 TK [Ki, 0.09 and 0.19 microM for (+)-C-BVDU and (+)-C-IDU and 0.16 and 0.19 microM for (-)-C-BVDU and (-)-C-IDU, respectively]. The inhibition of HSV-1 TK by BVDU, IDU, (+)-C-BVDU, and (+)-C-IDU was purely competitive with regard to the natural substrate (thymidine), whereas (-)-C-BVDU, (-)-C-IDU, (+/-)-C-BVDU, and (+/-)C-IDU showed a linear mixed-type inhibition of HSV-1 TK. C-BVDU and C-IDU are examples of chiral molecules of which both isomeric forms are markedly active at both the cellular and enzymatic level.

Animals↗
PubMed1989

Sugar modified oligonucleotides. I. Carbo-oligodeoxynucleotides as potential antisense agents.

For the first time, carbo-oligodeoxynucleotides, namely c-dT4 and c-dT12, have been synthesized. As compared to the natural oligomers these carbo-oligodeoxynucleotides are at least 5 times more stable toward enzymatic degradation and bind more strongly to complementary DNA. These preliminary data indicate that such oligomers fulfill the requirements to be considered as potential antisense agents.

Base Composition↗
PubMed1989

[Changes in the catecholamine plasma level 3 months after aortocoronary bypass operation].

Plasma catecholamine levels were obtained during diagnostic heart catheterization from the pulmonary artery and aorta and, similarly, renin levels were determined in the pulmonary artery in 31 patients with coronary heart disease and 18 normal controls. 3 months after aorto-coronary bypass surgery the patients with coronary heart disease underwent repeat heart catheterization and the epinephrine, norepinephrine and renin levels were compared with those obtained before operation. Norepinephrine decreased in the aorta from (means +/- SEM) 475 +/- 57 pg/ml to 360 +/- 38 pg/ml (p less than 0.001) postoperatively (controls 225 +/- 21 pg/ml). Epinephrine decreased from 121 +/- 11 pg/ml to 108 +/- 16 pg/ml (p less than 0.001) postoperatively (controls 84 +/- 9 pg/ml). This shows that postoperative relief from myocardial ischemia is associated with normalization of the preoperatively elevated plasma catecholamine levels).

Adult↗
PubMed1989

Synthesis and antiviral activity of the enantiomeric forms of carba-5-iodo-2'-deoxyuridine and carba-(E)-5-(2-bromovinyl)-2'-deoxyuridine.

Both enantiomers of the carbocyclic analogues of 5-iodo-2'-deoxyuridine (14 and ent-14) and of (E)-5-(2-bromo-vinyl)-2'-deoxyuridine (16 and ent-16) were synthesized by using (+)- or (-)-endo-norborn-5-en-2-yl acetate or butyrate, respectively, as starting materials. Against herpes simplex virus type 1 (+)-C-BVDU (16) was only slightly less active than BVDU itself, whereas (-)-C-BVDU (ent-16) proved to be 10-400-fold less effective, depending on the strain investigated. Against HSV-2 both (+)- and (-)-C-BVDU as well as (+)- and (-)-C-IDU showed minor activity. All carbocyclic analogues were inactive against TK-HSV-1 strains, pointing to the prerequisite of phosphorylation (activation) by the viral thymidine kinase (TK).

Antiviral Agents↗
PubMed1989

Functional evaluation of the spinal cord by magnetic resonance imaging in patients with rheumatoid arthritis and instability of upper cervical spine.

Thirty-four patients with atlanto-axial instability due to rheumatoid arthritis were examined with plain x-ray views and functional magnetic resonance imaging (MR), and were neurologically evaluated. Transcranial brain stimulation was performed in 25 patients. In 22 cases, the authors observed inflammatory tissue thicker than 3 mm behind the odontoid peg. The spinal canal diameter was significantly decreased in the flexed position. Nine patients showed signs of cranial migration of the axis. The diameter of the spinal cord was measured to be 7.4 mm in the neutral position, and 6.5 mm in flexion. The difference between the diameter of the neutral and flexed positions was highly significant. Twelve of the 34 patients displayed clinical signs of cervical myelopathy, and 13 showed a significant delay of central motor latency, as calculated from the motor evoked potentials. Surgical intervention, either by a posterior approach only or combined with a transoral dens and inflammatory tissue resection, is recommended in patients with progressive atlanto-axial instability, pathologic clinical and neurophysiologic findings, and a spinal cord diameter of less than 6 mm in flexion. Severe pain and cranial migration of the axis, as measured by the MRI, also justify a surgical intervention.

Adult↗
PubMed1988

Quantitation of aortic regurgitation by colour coded cross-sectional Doppler echocardiography.

In 60 patients with aortic regurgitation, angiography and cross-sectional Doppler echocardiography have been compared in order to examine the reliability of the noninvasive method in quantitating aortic regurgitation. In a parasternal short-axis view just below the aortic valve, the ratio of the cross-sectional area of the jet divided by the cross-sectional area of the left ventricular outflow tract was determined. This measurement was possible in 50 patients (83%). Grossman's classification was used as the criterion for assessing the severity of aortic regurgitation by angiography. Values for the ratio of grade I ranged from 0.03 to 0.18, II 0.06 to 0.29, III 0.30 to 0.55, and IV 0.40 to 0.65. Assuming four Doppler grades (less than 0.15, 0.15-0.29, 0.30-0.44, greater than or equal to 0.45), we found complete agreement between the two methods in 42 patients (84%). In six cases there was underestimation, in two cases overestimation, by one grade only. Considering all cases, X2 analysis gave 96.6, P less than 0.00001, the contingency coefficient was 0.81. We conclude that, using this measurement, cross-sectional Doppler is a reliable method for the quantitative evaluation of aortic regurgitation.

Adult↗
PubMed1988

Functional radiographic diagnosis of the cervical spine: flexion/extension.

The cervical spines of 59 adults were examined by means of functional roentgenograms. They were divided into two groups consisting of 28 healthy adults and 31 patients who had sustained soft tissue injury to the cervical spine and who were complaining of neck pain. Roentgenographic lateral views were taken in active flexion and extension as well as in passive maximal flexion and extension. Measurements using the techniques of Penning and Buetti-Bauml were made by three observers independently. There was a highly significant difference between the active and passive segmental ranges of motion in healthy adults. Based on the normal values obtained in this study, 19 hypermobile segments could be diagnosed during the active examination, while 31 hypermobile segments were found during the passive examination. In addition, the active examination found 60 hypomobile segments, while the passive examination showed only 43 hypomobile segments. The Penning Method of measurement was found to be more reliable than that of Buetti-Bauml. If possible, the functional roentgenogram examination of the cervical spine in the sagittal plane should be performed by including passive movement and the range of motion should be compared with the normal values obtained by passive examination.

Adult↗
PubMed1988

[Plasma catecholamine level in diagnostic heart catheterization studies].

Plasma catecholamine levels were obtained during diagnostic heart catheterization from pulmonary artery and aorta before and after injection of contrast medium in 31 patients with coronary heart disease and in 18 normals. The most striking difference between both groups is a significant decline of norepinephrine concentration in aortas after injection of contrast medium in the normals (from 296 +/- 24 [mean +/- SEM] to 225 +/- 21 pg/ml [p less than 0.01]) and no change in patients with coronary heart disease. The cause seems to be rather increased elimination than a decrease of secretion of norepinephrine. Adrenalin shows only partially similar results. Further studies will have to show, what could be the reason for these different reactions of catecholamine level in normals and in patients with coronary heart disease.

Adult↗
PubMed1987

[Clinical value of Doppler sonography in the quantification of aortic stenoses].

Results of CW-Doppler measurements in 34 patients with aortic stenosis have been compared with catheter-derived data. The relevance of this noninvasive method for clinical decision making was examined. There was a good correlation between Doppler peak gradients and corresponding catheter values (r = 0.96). This gradient, however, was of limited clinical significance because, especially with simultaneous aortic insufficiency, it was not possible to characterize the severity of the stenosis over a wide range. The correlation for the mean gradient of both methods was also excellent (r = 0.94). Hence it was possible to derive, in a noninvasive way, a clinically proven parameter of the severity of aortic stenosis. 90% of Doppler mean gradients were found within +/- 15 mm Hg of the corresponding catheter data. The ratio of modified time to peak to modified ejection time was calculated to characterize spectral shapes. This value was also well correlated with the mean gradient (r = 0.91). A ratio of 0.3 separated patients with mean gradients above or below 50 mm Hg. The simultaneous consideration of Doppler derived mean gradient and spectral shape proved to be a valuable method for quantifying aortic stenosis for clinical purposes.

Adolescent↗
PubMed1986

[Guided training as a therapeutic measure in the treatment of hyper- and hypotension].

The high prevalence of hypertension and orthostatic hypotension is a challenge for both preventive and curative medicine. Physical exercise can be of great therapeutic value in these disturbances of blood pressure regulation. Endurance training has been shown to normalize resting and exercise blood pressure in young borderline hypertensives. Other beneficial effects include a decrease in myocardial oxygen consumption (tension-time index) and plasma adrenaline levels at rest and during exercise and an improvement in left ventricular compliance. This can bei achieved without the risks and expense of long-term drug therapy. When medication is needed for the therapy of hypertension, drug-induced changes in blood pressure reaction and circulatory responses to physical training have to be considered. We found that orthostatic hypotension in otherwise healthy people is often associated with poor general physical condition. In such cases endurance training combined with isometric exercise aimed at increasing leg muscle tone is advisable. However, exercise training as a therapeutic measure has to be prescribed in terms of dose (frequency and duration), intensity and type of exercise. This requires an understanding of exercise physiology, as well as the ability to make a rational selection and evaluation of patients using a graded exercise test.

Adult↗