Pharmacological actions of the selective and non-selective beta-adrenoceptor antagonists celiprolol, bisoprolol and propranolol on human bronchi

1. The pharmacological actions of the beta-adrenoceptor antagonists, celiprolol, bisoprolol and propranolol were investigated in human lung tissue by radioligand binding experiments as well as in human isolated bronchi by functional experiments in organ baths. 2. Data from lung tissue were compared to those obtained from myocardial membranes. 3. Lung tissue was obtained from 10 patients having undergone lung resection for bronchial carcinoma and myocardial tissue from a patient who had received a heart transplantation. 4. In radioligand binding experiments, celiprolol exhibited a high affinity binding to beta 1-adrenoceptors in heart and a low affinity binding to beta 2-adrenoceptors in lung tissue. The selectivity obtained for the beta 1-adrenoceptor was calculated to a factor of eleven. 5. Compared to bisoprolol and propranolol, celiprolol elicited the lowest affinity for the beta-adrenoceptor, as judged from the K1-values. 6. In the absence and presence of the guanine nucleotide Gpp(NH)p celiprolol did not affect receptor binding. 7. In functional experiments on intact bronchi, celiprolol, bisoprolol and propranolol failed to produce relaxation (+/- forskolin) or a significant difference in efficacy in antagonizing the relaxant effects of isoprenaline. However, a rank order of potencies was revealed (propranolol:bisoprolol:celiprolol = 46:12:1). 8. Plasma concentrations for celiprolol and bisoprolol usually achieved in vivo were below the IC50 value obtained in vitro. In contrast, for propranolol, plasma concentrations were nearly identical with the IC50 value. 9. It is concluded that celiprolol is a selective beta 1-adrenoceptor antagonist on human heart and has no agonistic properties on intact human bronchi. Compounds such as celiprolol and bisoprolol may in comparison to propranolol, possess reasonable therapeutic advantages in the treatment of patients with obstructive lung disease due to their low affinity for beta 2-adrenoceptors.

Autonomous concentration-dependent activation and repression of Kruppel by hunchback in the Drosophila embryo

The subdivision of the anterior-posterior axis in Drosophila is achieved by a cascade of spatially regulated transcription factors which form short-range gradients at the syncytial blastoderm stage. These factors are assumed to have concentration-dependent regulatory effects on their target genes. However, there is so far little direct in vivo evidence that a single factor can autonomously activate and repress a given target gene. We have analysed here the regulatory capabilities of the gap gene hunchback by creating an artificial gradient of hunchback in the early embryo. This was achieved by providing the maternally expressed mRNA of hunchback with the anterior localization signal of the bicoid RNA. The effects of this artificial hunchback gradient were then studied in different types of mutant background. We show that under these conditions hb is autonomously capable of activating the target gene Kruppel at low concentrations and repressing it at high concentrations. In addition, we show that the artificially created hunchback gradient can organize a large part of the segment pattern, although it is expressed at a different position and in a different shape than the wild-type gradient of hunchback.

[Penetrating thoracic injuries--a 10 year analysis of 179 patients]

179 patients with penetrating chest wall and thoracic injuries were treated at the University Hospital "Rudolf Virchow" in Berlin between 1982 and 1992. Most patients (72.4%) were successfully treated with closed tube thoracostomy alone. 33 (18.4%) patients required thoracotomy, 14 (7.8%) due to injury of the great vessels and 15 (8.3%) due to cardiac injuries. In 10 (5.5%) patients also abdominal organs were compromised, so that also a laparotomy had to be done. Seven (3.9%) patients died. All but one patients who died, died in the OR or within 24 h of admission. So lethality in the group of cardiac wounds was 44.6% (7 out of 15). This underlines the necessity of most rapid transport to the hospital in case of thoracic injury.

The stress-, but not corticotropin-releasing hormone-induced activation of the pituitary-adrenal axis in man is blocked by alprazolam

A number of experimental studies clearly suggest that benzodiazepines attenuate the corticotropin-releasing hormone (CRH) secretion possibly through inhibitory GABAergic neurons. There is some evidence that benzodiazepines act to inhibit stress-induced activation of the hypothalamic-pituitary-adrenal axis. A comparison of the effects of a benzodiazepine on the stress- and CRH-induced activation in man has not been undertaken so far. We thus investigated the effects of the triazolobenzodiazepine alprazolam on both the stress- and CRH-induced changes in ACTH, cortisol, and prolactin secretion in ten healthy volunteers. In addition, hemodynamic parameters were studied. The subjects received either alprazolam (0.5 mg orally) or placebo 90 min prior to administration of CRH (100 ug i.v.) and to the performance of a mental stress technique. Blood samples, blood pressure and heart rate were taken every 15 min. The administration of alprazolam led to a highly significant attenuation of the ACTH increase following the stress interview. While ACTH increased from 12.4 to 26.7 pg/ml 15 min after the stress procedure in the placebo condition, there was almost no increase following alprazolam intake. An identical effect was found for cortisol secretion. Basal levels of prolactin were slightly enhanced in the alprazolam situation, while the stress-induced increase was not attenuated. Basal and stimulated systolic and diastolic blood pressure levels and heart rate were also significantly attenuated by alprazolam intake. Following administration of CRH, the ACTH augmentation was only slightly affected following alprazolam, while there were no changes in cortisol and prolactin secretion.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of thyrotropin- and corticotropin-releasing hormone on blood pressure and plasma catecholamines in the anesthetized rat

The neuropeptides thyrotropin-releasing hormone (TRH) and corticotropin-releasing hormone (CRH) have been found to be potent stimulators of the autonomic nervous system in both experimental animals and humans. We studied the effects of different doses of CRH and TRH given intracerebroventricularly in the urethane-anesthetized rat and a single dose of CRH in the chloral hydrate-anesthetized rat to elucidate the effects of these peptides in the unconscious state. All TRH doses studied enhanced blood pressure and noradrenaline and adrenaline secretion. Surprisingly, there were no blood pressure increases following administration of 0.4, 1.3 and 1.7 nmol CRH. In general, there was a tendency for blood pressure to decrease with the largest drop observed after 1.7 nmol CRH. Our data suggest that only TRH clearly augments blood pressure and catecholamine secretion in the anesthetized animal, while CRH does not exert major effects under the two anesthetic conditions employed.

[Resection with primary anastomosis in complicated diverticulitis. Risk analysis]

107 patients operated for complicated diverticulitis 1988 until 1993 were analysed retrospectively regarding perioperative risk of resection with primary anastomosis (n = 94). 53 of them had peridiverticulitis with stenosis (mortality 0), 41 had emergency operations (mortality 14.6%). Hartmann procedure (n = 13, mortality 7.6%) has been accepted only for the following situations: 1. ileus with secondary damage of the bowel, 2. extended diffuse peritonitis with secondary organ failure, 3. poor blood supply of the bowel, 4. the patient under immunosuppression after transplantation. Regarding these recommendations mortality rate in emergency operations (12.9%) has been lower as compared to 15 to 20% in literature. So regarding the recommendations named above resection with primary anastomosis seems to be a safe procedure in complicated diverticulitis.

[Cholinergic action of Bay K-8644 on the rat heart sinus node automaticity]

The actions of different concentrations of a dihydropyridine agonist (Bay K-8644) on rat heart sinus node automaticity and their interactions with atropine, were studied. The experiments were performed using a portion of the right atrium that contained the sinus node, perfused with Tyrode's solution at 37 degrees C and registering the action potentials with intracellular microelectrodes (Ag-KCL). The series of Bay K with or without atropine were perfused during 10 min. Atropine, 1 x 10(-5) M, did not change sinus frequency after 30 min of perfusion (237 +/- 6 to 229 +/- 7 action potentials/min; n = 24). Bay K, 2.8 x 10(-8) M (10 ug/L) did not change sinus frequency (240 +/- 9 to 246 +/- 12; n = 8, but in the presence of atropine, caused an increment (225 +/- 7 to 256 +/- 12 p < 0.05). Bay K, 7 x 10(-8) M (25 ug/L) and 1.4 x 10(-7) M (50 ug/L, caused an increase in sinus frequency (237 +/- 5 to 279 +/- 15; n = 9 p < 0.05 and 254 +/- 6 to 291 +/- 6; n = 6 p < 0.05 respectively) that occurred sooner in the presence of atropine. It is concluded that Bay-K has a cholinergic effect that interferes with its positive chronotropic action, specially at low concentrations.

Adrenocortical carcinoma in children: clinical aspects and prognosis

Although adrenocortical carcinoma is seen infrequently in children in most countries, it is occurs with significant frequency in Southern Brazil. This has enabled a study of the pattern of this disease in the pediatric age group. Of 78 patients with adrenocortical carcinoma seen at two hospitals in Curitiba, Brazil, 55 were adequately documented, with minimum of 2 years' follow-up, and formed the basis of this paper. Ninety-five percent of the patients showed some degree of virilization, notably pubic and/or body hair, clitoris or penis enlargement, and adult voice. Cushing's syndrome was present in 73% of these cases. The prognosis is age related and is dependent on the resectability of the tumor. Whereas 82% of the children under the age of 2 years survived, the figure for those over the age of 2 years was only 29%. When total resection of the tumor was possible, the survival rate was 67%, with no survival when only partial excision was performed.

Cardiac inotropic as well as coronary and pulmonary artery actions of epinine in human isolated tissues

The present study was aimed to characterize the effects of epinine, the metabolite of the p.o. active dopamine derivate ibopamine in human cardiovascular tissues such as myocardium, coronary artery and pulmonary artery. Isometric force of contraction was studied in electrically driven papillary muscle strips from nonfailing (brain death), moderately failing (New York Heart Association class II-III, mitral valve replacement) and terminally failing human myocardium (New York Heart Association class IV, heart transplants) as well as in auricular trabeculae (aortocoronary bypass operation). Epinine increased force development in a concentration-dependent manner. In comparison to isoprenaline, epinine had a significantly lower potency but a similar efficacy to enhance force of contraction. Depending on the degree of myocardial failure, the effectiveness of epinine was reduced, whereas the potency was similar. Only in nonfailing myocardium, epinine increased force of contraction as effectively as Ca++. Prestimulation with forskolin or milrinone enhanced the potency of the epinine-mediated inotropic effect. In contrast, the beta-1-selective antagonist CGP 207.12A [2-hydroxy-5-(2-(hydroxy-3-(4-((1-methyl-4-trifluoromethyl)-1-H-imidazol -2-yl)-phenoxy)-propyl)-aminoethoxyl)-benzamide] and the beta-2-selective antagonist ICI 118.551 [erythro-(+-)-1-(7-methylindan-4-yloxy)-3- isopropylaminobutan-2-ol-hydrochloride] shifted the concentration-response curve of epinine significantly to the right, indicating action at both beta-2 and beta-1 adrenoceptors. Epinine exerted higher affinity at beta-2 compared to beta-1 adrenoceptors in radioligand binding experiments ([125I]iodocyanopinodolol). In human coronary artery rings and pulmonary artery rings epinine alone as well as epinine in the presence of propranolol initiated a concentration-dependent increase in tension development in precontracted (prostaglandin F2 alpha, 0.3 mumol/l) as well as in non-precontracted rings. These results suggest that epinine exerts no direct vasodilatory activity in human coronary and pulmonary arteries at concentrations which are capable to produce positive inotropic activity. The supposed beneficial effects of ibopamine in the treatment of heart failure may not be due to positive inotropic actions as the concentrations producing positive inotropy are much higher than the clinically observed plasma concentrations.

Positive inotropic effects due to partial agonistic activity of the beta-adrenoceptor antagonist celiprolol following amplification of cAMP formation in failing human myocardium

The present study investigated the effects of celiprolol a novel beta 1-antagonist with partial beta 2-agonist activity on the human failing heart. Experiments were performed on isolated electrically driven atrial and ventricular cardiac preparations and in membrane preparations from the left ventricles of nine patients (four with dilated cardiomyopathy; five with ischemic cardiomyopathy) undergoing cardiac transplantation for terminal heart failure. Celiprolol produced a negative inotropic effect in atrial and ventricular heart muscle. However, in the presence of forskolin--which activates the catalyst of the adenylate cyclase-or the cAMP phosphodiesterase inhibitor milrinone, celiprolol produced concentration-dependent positive inotropic effects and positive lusitropic effects. Experiments with the beta 1-and beta 2-selective antagonists CGP 207.12A and ICI 118.551, respectively, suggest that the positive inotropic response is mediated by beta 2-adrenoceptors. In radioligand binding experiments, a selectivity of 15.7 [-Gpp(NH)p] or 23.9 [+Gpp(NH)p] as judged from the Ki values--of binding to beta 2-adrenoceptors was measured in the failing human ventricular myocardium. Competition curves with celiprolol alone and in the presence of the guanine nucleotide Gpp(NH)p revealed no evidence for agonist activity at beta 1- or beta 2-adrenoceptors. It is concluded that amplification of the cAMP response is able to unmask partial agonist activity of celiprolol in the failing human heart at beta 2-adrenoceptors. The inotropic measurements are a more sensitive approach than radioligand binding studies. Whether the pharmacological profile of celiprolol will be useful in conditions like heart failure is questionable with respect to the potential downregulation of beta 2-adrenoceptors by its partial agonist activity.

Force-frequency relationship and inotropic stimulation in the nonfailing and failing human myocardium: implications for the medical treatment of heart failure

In isolated papillary muscle strips from nonfailing donor hearts (NF) and from the hearts of patients with dilated cardiomyopathy with severe heart failure (NYHA IV), the force-frequency relationship was studied. Experiments were performed under basal conditions and in the presence of 0.01 microM or 0.1 microM isoprenaline and 0.02 microM ouabain. In NF, there was a positive inotropic effect following an increase of the stimulating frequency, whereas in NYHA IV, the force gradually declined under these conditions. Low concentrations (0.01 microM) of isoprenaline prevented the negative inotropic effect in NYHA IV, whereas at 0.1 microM the mechanical function deteriorated in NF and NYHA IV. Ouabain had no effect on the force-frequency relationship compared to basal conditions. It is concluded that a reduction of high frequencies does improve the contractility in the failing myocardium. It is not unreasonable to speculate that this mechanism might be involved in the beneficial effects of drugs which reduce the heart rate, such as beta-adrenoceptor antagonists and cardiac glycosides, in the condition of congestive heart failure in which the sympathetic tone is high.

Na(+)-channel activators increase cardiac glycoside sensitivity in failing human myocardium

Na(+)-channel activators increase intracellular Na+ and thereby enhance the transport rate of sarcolemmal Na+,K(+)-ATPase. We investigated the interaction of the new Na(+)-channel activator BDF 9148 (BDF) with the cardiac glycoside ouabain (OUA) in human myocardium. The influence of OUA (0.01-0.1 microM) and of OUA after prestimulation with BDF (0.1 microM, 1 microM; BDF+OUA) on isometric force of contraction (FOC, force of contraction; +T/-T, peak rate of tension increase/decay) of electrically driven (1 Hz, 37 degrees C) papillary muscle strips from terminally failing [New York Heart Association classification IV (NYHA IV) heart transplants, n = 19] human myocardium was studied. We also examined the effects of BDF and OUA on nonfailing human myocardium (brain death resulting from traumatic injury, n = 5). 0.01 microM OUA enhanced FOC only after prestimulation with BDF (NYHA IV+2.9 +/- 0.4 mN; p less than 0.01). The time until maximal (Tmax: BDF+OUA 117 min, OUA 166 min), half-maximal (T1/2max: BDF+OUA 47 min, OUA 85 min) inotropic effects and time until toxic signs (contracture, extrasystoles) occurred were significantly shorter with BDF+OUA as compared with OUA alone. BDF influenced Tmax, T1/2max, and time until toxic side effects occurred (Ttox) of the OUA-mediated inotropism in a concentration-dependent manner. Both OUA and BDF enhanced +T and -T. The effectiveness of OUA and BDF in increasing FOC was similar to that of Ca2+ (1.8-15 mM) but significantly (p less than 0.01) higher as compared with the beta-adrenoceptor-agonist isoprenaline in NYHA IV. In myocardial membranes, [3H]ouabain binding (Bmax, Kd) was not affected by BDF.(ABSTRACT TRUNCATED AT 250 WORDS)

Organ donation: the role of hospitals

Three models of cooperation between hospitals and transplant centres are: (1) performance of brain death diagnosis, organ removal and preservation at the peripheral hospital; (2) performance of brain death diagnosis at the peripheral hospital and transportation of the dead body under ICU modalities to the transplant centre; (3) transport of a potential organ donor to the transplant centre. The key issues for success in cooperation between peripheral hospitals and transplant centres are: positive attitudes of hospital representatives; motivation and acceptance of ICU staff, supported by the whole community; and availability of adequate facilities to perform organ recovery in practice.

[Frequency of hypoxic episodes during general anesthesia in children]

We measured the frequency and extent of arterial hypoxemia during pediatric general anesthesia under routine clinical conditions. The subjects were 91 children (13 newborns, 27 infants, 37 children under 6 years, 14 children under 14 years) with normal heart and lungs scheduled for extrathoracic surgery. Mask anesthesia (spontaneous/assisted ventilation) was performed in 30 cases, endotracheal anesthesia (controlled ventilation) in 61 cases. Arterial oxygen saturation (SaO2) was determined by pulse oximetry at entry into the operating room and recorded continuously from induction of anesthesia to emergence. Hypoxic episodes (minimum duration: 30 s) were classified as slight (SaO2 less than or equal to 95%), minor (SaO2 less than or equal to 90%) and major (SaO2 less than or equal to 85%). The data were analyzed with the Fisher's test. 52% of all children experienced at least one hypoxic episode. Frequency and extent of hypoxic episodes decreased as age and weight of the children increased. Major hypoxic episodes occurred in 54% of the newborns, 26% of the infants, 8% of the children under 6 and 7% of the children under 14. A body weight of 10 kg appeared to constitute a threshold: in children below this weight arterial oxygen desaturation occurred significantly more frequently (p less than 0.001), and the incidence of major episodes was significantly higher (p less than 0.005). Major episodes were almost evenly distributed between induction and awakening from anesthesia, only one episode occurred during maintenance. Desaturation was more likely to occur in intubated children than in those with a mask (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Management practices, physician autonomy, and satisfaction. Evidence from mental health institutions in the Federal Republic of Germany

Physicians are moving into organized settings where their autonomy is more constrained and where management has more responsibility for physician satisfaction. The relationship of management practices to physician autonomy and satisfaction was explored in a survey of 185 psychiatrists in the State of Hessen in the Federal Republic of Germany (FRG). Analysis revealed that controlling for physician and institutional characteristics, management practices in relationship to participative activities, supportive communication, and peer review activities were the most important predictors both of perceived clinical autonomy and of work satisfaction. Gender was also a factor in that male physicians experienced greater perceived autonomy. Perceived clinical autonomy was an important factor in explaining satisfaction, whereas a few other physician and institutional characteristics were significant in predicting satisfaction. Unexpectedly, there was more perceived clinical autonomy among psychiatrists in larger, less well funded, more managerially constrained, state institutions than in smaller, community general hospitals and private organizations. Implications for further research are discussed.

Effect of epidermal growth factor in severe experimental alkali burns

Ten rabbits with the right eye burnt by 1 N NaOH were treated 5 times daily with epidermal growth factor (EGF) eyedrops or placebo. The epithelium seemed to heal better under EGF treatment than with placebo. Also, ulceration and secondary calcification of the cornea were reduced in the EGF-treated group. The vascularisation was slightly diminished by EGF. The lactate dehydrogenase and N-acetylglucose aminidase activities and the lactate and glucose levels in the corneae were not different between the EGF and the placebo groups. The results showed that there was a beneficial effect of EGF in these experiments with most severe eye burn disease. But the improved regeneration of the epithelium seemed to be counteracted and partly abolished by the severe inflammatory reaction in these eyes.

Hydraulic conductivity of venous endothelium as measured with a volume clamp method

Hydraulic conductivity (Lp) of cava vein endothelium was obtained with a new method that measures fluid flow at constant volume. Dogs were anesthetized with pentobarbital sodium. A vessel segment was removed, cannulated, and hung free from a force transducer calibrated to measure weight. Hydraulic pressure difference drove fluid across the vessel wall. This fluid was washed out from the vessel surface by external perfusion, causing a weight loss that was transmitted to a Grass polygraph through the force transducer. Shifting the polygraph balance caused a voltage output which was used to activate a controller operating a microsyringe pump. By injecting fluid into the vessel lumen, this servomechanism counteracted weight changes and kept volume and pressure at a fixed level. Recording the volume injected allowed continuous monitoring of fluid flow. This avoided the problems caused by frequent pressure and volume resetting in previous methods. Fluid flow was a linear function of the applied pressure (r = 0.87). Lp was 0.91 +/- 0.05 (SD) X 10-7 cm X s-1 X cmH2O-1. This value was very similar to those in continuous capillaries and arterial endothelium.

Organ procurement in Munich: financial and organizational aspects

The Transplantation Center at the University of Munich is like all other German centers financially supported by the Insurance Companies via a non-profit organization (Kuratorium für Heimdialyse e.V.). The financial modalities are based on the arrangement that the Insurance Companies pay a certain amount for each transplantation to the non-profit organization. This institution, in cooperation with the University, uses this money to cover all extra expenses arising in the field of organ procurement as well as clinical transplantation (providing additional staff, equipment, etc). This model of a transplant center (ie, cooperation between University and non-University institutions) proved to be successful in the past 9 years. There was a steady increase of donor nephrectomies (200 donor kidneys in 1984) as well as kidney transplantations (171 transplantations in 1984).

Neuropsychological function following mild exposure to pentaborane

Neuropsychological tests and self-report personality inventories were administered to 14 workers and rescue squad personnel approximately 2 months following mild exposure to pentaborane, a highly toxic volatile liquid boron hydride. Performance decrements were evident on 5 of 11 neuropsychological tests, including Block Design and measures of sustained attention and recent memory. Neuropsychological deficits were not related to emotional changes reported on the Hopkins Symptom Checklist nor to the presence of CT scan abnormality. These results indicate mild residual brain dysfunction following pentaborane intoxication, including possible dysfunction in subcortical regions mediating memory processes and in cortical areas mediating visuo-spatial abilities.

Violent automatism in a partial complex seizure. Report of a case

We describe a patient who had a violent automatism that occurred during a partial complex seizure. The initial spike wave activity was recorded from nasopharyngeal leads that were lost as the patient began his vigorous, violent activity. This activity included nondirected, automatic, stereotyped behavior with physical assaults on objects in his path.

Cytochrome P450cam and its complexes. Mössbauer parameters of the heme iron

Mössbauer spectroscopy has been used to study the heme iron in various states of cytochrome P450cam from the camphor-hydroxylating system of the bacterium Pseudomonas putida. Native, camphor-free P450cam contains low-spin ferric iron, part of which (approx. 50-70%) is converted to the high-spin ferric state upon addition of camphor. The Mössbauer spectra of the camphor-free enzyme (S equals 1/2) and of the high-spin component (S equals 5/2) of the camphor complex have been successfully simulated using a model based on crystal-field theory and simple convalency considerations. The native low-spin ferric state of P450cam forms a complex with 2-phenylimidazole, with small changes in the g values and Mössbauer spectra. These changes can be accounted for consistently in the crystal-field model referred to above. The addition of putidaredoxin to the camphor-complexed, oxidized P450cam decreases the intensity of the high-spin component and changes its quadrupole splitting. The reduced form of P450cam contrins high-spin ferrous iron, both in the presence and absence of camphor. The complex of reduced P450cam with molecular oxygen is diamagnetic and has a combination of quadrupole splitting and isomer shift that is unusual for a ferrous complex, but strongly resembles that of oxyhemoglobin. These results are compatible with the bound superoxide, Fe3+-O-2, model proposed for oxyhemoglobin (Weiss, J. J. (1964) Nature 202, 83-84). Reduced P450cam and its complexes, oxyP450cam-CO, are all found to be analogous in some respects to the corresponding hemoglobin complexes.