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Biomedical subjects

R Mohr

Publications and source records attributed to R Mohr.

117 records · Page 7Linked to original sources
PubMed1976

Helper T-cell kinetics and investigation of antigen receptor expression on early and memory T-helper cells.

The subcutaneous application of soluble antigen resulted in generation of helper T lymphocytes in the draining lymph nodes, tested 4 days after priming in the adoptive transfer system. Four days later a specific helper T-cell population was detected in the spleen. B-cell activity could be demonstrated 4-5 days after helper T-cell activity in both organs. We investigated the early helper T-cell population and memory T cells with respect to differences in the expression of antigen receptors. No such differences could be detected, either by anti-immunoglobulin-coated Degalan columns or by an antigen-specific rosetting method.

Animals↗
PubMedDate not supplied

Acquired left ventricular-right atrial communication caused by infective endocarditis detected by transesophageal echocardiography: case report and review of the literature.

Acquired left ventricular-right atrial communication due to infective endocarditis was diagnosed in a 64-year-old patient by transesophageal echocardiography and confirmed by cardiac catheterization. The patient was initially treated medically and then referred for corrective surgery.

Echocardiography, Transesophageal↗
PubMedDate not supplied

Comparison of vasoactive response of left and right internal thoracic arteries to isosorbide-dinitrate and nitroglycerin: an in vitro study.

OBJECTIVE: The internal thoracic artery (ITA) is the most important graft in coronary artery bypass grafting. Its distal region is, however, prone to vasospasm. We studied the effects of nitroglycerin (NTG) and isosorbide-dinitrate (DSDN) on distal segments of left versus right ITA. METHODS: Rings of distal segments (6 to 9 mm proximal to bifurcation) of the human left and right ITA were studied. After baseline contraction of the rings, achieved using 60 mmol/L of KCl, they were exposed to increasing doses of ISDN and NTG (10 to 100 microg/ml), and dose-response curves were recorded. RESULTS: The contractile response of left ITA rings to KCl were significantly lower than those of right ITA rings (1.87 +/- 0.25 g versus 3.5 +/- 0.61 g, p < 0.005). Both nitrates inhibited the contractile response in a concentration-dependent manner, with relaxing effects of ISDN higher than those of NTG (p < 0.01) in both left and right ITA rings. CONCLUSIONS: The distal segment of the left ITA is less prone to vasospasm than that of the right. ISDN has a considerably higher relaxant effect on this segment than NTG. We therefore recommend favoring high doses of ISDN over NTG as an antispastic measure.

Coronary Artery Bypass↗
PubMedDate not supplied

Qualitative evaluation of antegrade percutaneous transluminal angioplasty by pressure waveform parameters.

When percutaneous transluminal angioplasty (PTA) is performed in an antegrade ("downstream") direction, intraluminal gradient measurements across the stenotic segment are not possible. Pressures recorded proximal to the lesion were evaluated for possible hemodynamic clues of changes in flow in ten consecutive patients before and after PTA. In all patients in whom the procedure was successful, the systolic pressure decreased by an average of 35 mm Hg. This decrease was not evident in the failed procedures. It is concluded that proximally recorded pressure changes can be used as an objective criterion to assess the success of PTA performed in arteries.

Aged↗
PubMedDate not supplied

Updated review of the coronary artery bypass grafting option in octogenarians: good tidings.

This review of the literature is presented in an attempt to keep pace with the constantly changing statistics in postsurgical outcomes, which reflect the considerable strides in technology and technical skills that have been made during the past decade in cardiovascular surgery. Although there is still much to be done in terms of improving surgical techniques and managing emergency cases, the reported results of coronary artery bypass grafting in octogenarians are similar to or even better than those obtained with medical or angioplastic approaches, and the life expectancy and quality of life are similar to or better than those of age-matched controls.

Aged↗
PubMedDate not supplied

A method for continuous on-line monitoring of systemic vascular resistance (COMS) after open heart procedures.

A new method for continuous on-line measurement (COMS) of systemic vascular resistance (SVR) utilizing simple computer analysis of the peripheral arterial waveform is presented. The fundamental equation of this method is: (Formula: see text) where SVR is systemic vascular resistance, dP/dt is the peak dP/dt of the peripheral arterial waveform, and P' is the pressure at the time of peak dP/dt. F and a are calibration constants determined by taking simultaneous measurements by an independent method (thermodilution) before (low SVR) and immediately after (high SVR) aortocoronary bypass operations. In 22 patients 255 COMS of SVR readings were recorded simultaneously with thermodilution cardiac output measurements. Patients were exposed to situations such as temperature changes, volume load, blood loss, and the effect of drugs such as various catecholamines, nitroglycerin, and nitroprusside. Linear regression analysis was performed to compare the SVR calculated from thermodilution with the COMS-SVR measurements. SVR values ranged from 450 to 4400 dynes/sec/-5 and correlation between COMS and thermodilution was r = 0.98. Correlation coefficients of individual patients ranged from r = 0.9 to r = 0.986. We found COMS SVR measurements accurate, reliable, and extremely helpful in the management of hemodynamically unstable patients.

Adult↗