Beitrag zur Lehre vom Pulsus intermittens und von der paroxysmalen Bradycardie

Ohne ZusammenfassungMit 3 Kurven.     

Ueber Leberveränderungen nach Gallengangsunterbindung

Ohne ZusammenfassungHierzu Taf. I u. II.     

Vaccination with Live Escherichia coli Expressing Brucella abortus Cu/Zn Superoxide Dismutase Protects Mice against Virulent B. abortus

Vaccination of mice with Escherichia coli expressing Brucella Cu/Zn superoxide dismutase (SOD) [E. coli(pBSSOD)] induced a significant level of protection against virulent Brucella abortus challenge, although this level was not as high as the one reached with B. abortus vaccine strain RB51. In addition, vaccination with E. coli(pBSSOD) induced antibodies to Cu/Zn SOD and a strong proliferative response of splenocytes when stimulated in vitro with a thioredoxin-Cu/Zn SOD fusion protein.     

Über kombinierte Stangsklerose

Ohne Zusammenfassung     

Free radical scavengers and myocardial preservation during transplantation

The efficacy of oxygen radical scavengers in preservation of left ventricular (LV) function after prolonged hypothermic global ischemia was investigated in a model of orthotopic cardiac transplantation in sheep. Group 1 hearts (N = 8) received hypothermic crystalloid cardioplegic solution, and were harvested and stored at 4 degrees C in balanced electrolyte solution for six hours prior to transplantation. Group 2 (N = 9) received identical treatment with the addition of 30,000 units of superoxide dismutase to the cardioplegic solution and the administration of 60,000 units of superoxide dismutase coincident with reperfusion. All animals were weaned from cardiopulmonary bypass. Preischemic and postischemic LV function was determined using sonomicrometry and a micromanometer-tipped LV catheter. Coronary blood flow was determined using standard microsphere techniques, and platelet deposition was assayed with autologous platelets labeled with indium 111. Lipid peroxidation products were measured using thiobarbituric acid assay. LV performance was significantly better (p less than .05) in Group 2 hearts when assessed by the slope of the end-systolic pressure-volume relationship and the stroke work versus end-diastolic volume relationship. There was better preservation of endocardial blood flow in the group receiving superoxide dismutase compared with controls (p less than .05). Platelet deposition, as determined by the tissue to blood ratio of scintigraphic counts, was greater (p less than .05) in controls compared with the group receiving superoxide dismutase. In addition, thiobarbituric acid reactive species were significantly less (p less than .05) in Group 2 versus Group 1 hearts.(ABSTRACT TRUNCATED AT 250 WORDS)     

Kidney transplantation improves baroreceptor sensitivity

Kidney transplant recipients as well as patients on hemodialysis frequently share an increased risk of cardiovascular diseases. Besides other factors, modulations in central neural blood pressure regulation have to be considered as a pathogenetic factor. In this study, baroreceptor function as a possible modulator of blood pressure and the activity of the generating components of the sympathetic nervous system were estimated in 20 kidney transplant recipients, 20 normotensive patients on hemodialysis and 20 age-matched volunteers using the sequence analysis technique and Fast Fourier Transformation (FFT). No blood pressure differences could be measured (83.7 ± 2.5 vs. 82.5 ± 3.8 vs. 79.2 ± 2.4 mm Hg). Pulse interval-blood pressure sequences and the slope of Δ pulse interval/Δ mean arterial blood pressure of these sequences, representing baroreceptor sensitivity, did not differ between kidney transplant recipients and controls (11.2 ± 1.4 vs. 13.4 ± 1.3 ms/mmHg), whereas in hemodialysis patients a reduced baroreceptor sensitivity (5.2 ± 1.2 ms/mmHg) was detected. The 66–129 mHz component (Mayer waves) of heart rate and blood pressure spectrum in normals (650 ± 57 and 630 ± 70 modulus) significantly (p < 0.05) exceeded its equivalent in kidney transplant recipients (430 ± 32 and 452 ± 27 modulus) and patients on hemodialysis (375 + 38 and 394 ± 40 modulus). In conclusion, our study provided evidence that both in kidney transplant and dialysis patients a decreased activity of the generating compounds of the sympathetic nervous system can be detected as compared to healthy volunteers. In contrast to hemodialysis patients, the baroreceptor sensitivity is unaffected in kidney transplant recipients and may, therefore, not contribute to the development of cardiovascular diseases.     

Acute and persistant effects of smoking on the baroreceptor function

1. Recent studies showed that to smoke four cigarettes within one hour impairs baroreflex sensitivity in humans. In the present study, these effects were qualified more precisely from blood pressure and heart rate records by a sequence analysis and by Fourier analysis of Finapres-registrations. 2. The Mayer waves of the heart rate PDS (power density spectrum), partially representing sympathetic activity, increased during smoking (83.7 ± 1.0 AU to 89.5 ± 1.1 AU, P≤ 0.05) and decreased after smoking (86 ± 1.0 AU, P≤ 0.05). They did, however, not reach baseline levels again within 30 min. Probably due to this, mean arterial blood pressure (64.3 ± 1.3 mmHg vs. 76.9 ± 1.3 mmHg, P < 0.05) and heart rate (71.8 ± 1.4 min^–1 vs. 82.9 ± 1.4 min^–1, P < 0.05) increased unequivocally after smoking. On the other hand, baroreflex sensitivity decreased dramatically from 15.4 ± 1 to 11.2 ± 0.6 ms mmHg^–l (P < 0.05). This finding was associated with an increased heart rate variability after smoking (6 ± 0.5 min^–1 vs. 9.2 ± 1 min^–1) 3. Thus, the present study provides evidence that chronic tobacco (nicotine)-abuse causes pathologic alterations of the baroreflex control. In synergism with other processes like elevated catecholamine blood levels, these alterations may contribute to the higher risk of cardiovascular diseases.     

Effects of 5-HT1A agonists and 5-HT2 antagonists on haloperidol-induced dyskinesias in squirrel monkeys: no evidence for reciprocal 5-HT-dopamine interaction

Dyskinetic movements and dystonic postures may be induced by neuroleptics in monkeys that have undergone previous neuroleptic treatment, and these motor abnormalities constitute a primate model of drug-induced extrapyramidal symptomatology. In view of previous suggestions that brain serotonergic systems may tonically inhibit dopamine neurons, the effects of several new and selective 5-HT₂ receptor antagonists and 5-HT_1A receptor agonists were investigated in this model. Setoperone, a dopamine D2 receptor antagonist with extremely potent 5-HT₂ antagonism, caused dyskinetic movements. Although ritanserin is a potent 5-HT₂ antagonist with very weak dopamine antagonist properties, this drug did not antagonize dyskinesias but induced them when administered at a high dose (30 mg/kg). Buspirone induced dyskinesias and blocked apomorphine-induced climbing, supporting prior reports that it has dopamine antagonist effects. Gepirone, a 5-HT_1A agonist with less marked dopamine antagonist properties, induced dyskinesias in only one of six monkeys at 30 mg/kg and did not block haloperidol-induced dyskinesias. 8-OH-DPAT partly attenuated haloperidol-induced dyskinesias, an effect possibly attributable to its weak dopamine agonist properties. Tonic inhibition of brain extrapyramidal dopamine systems by serotonin systems does not appear to characterize neuroleptic related dyskinesias in squirrel monkeys.