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Biomedical subjects

K Wiedemann

Publications and source records attributed to K Wiedemann.

At least 109 records · Page 6Linked to original sources
PubMed1987

Dexamethasone suppression test in severe schizophrenic illness: effects of plasma dexamethasone and caffeine levels.

A dexamethasone suppression test (DST) was administered to 31 inpatients with a severe acute schizophrenic exacerbation 4 or 5 days following admission and repeated after 4 weeks or prior to discharge. We identified 15 patients (48%) who were nonsuppressors on the DST at the first test. To exclude major confounders of DST results we monitored weight constancy and plasma concentrations of dexamethasone. In a subgroup of patients also plasma caffeine contents were determined. Our results indicate that DST nonsuppression occurs frequently among patients with schizophrenic crisis. Since caffeine plasma levels were indistinguishable between suppressors and nonsuppressors we reject that excessive caffeine intake accounts for DST nonsuppression among individuals with schizophrenia. Nonsuppressors had lower plasma dexamethasone levels than suppressors and reversal of the DST status from nonsuppression to suppression was associated with an increase of plasma concentrations of the test drug.

Adult↗
PubMed1987

[No indications for barbiturate therapy following complete cerebral ischemia. A comment on "cerebroprotection" by barbiturates following cardiovascular arrest].

Cardiac arrest is followed by complete cerebral ischemia, which is characterized by delayed hypoperfusion and transient hypermetabolism. Brain metabolism depressant drugs, such as barbiturates, were suggested to improve neuronal outcome. The hypothesis of a cerebroprotective effect of barbiturates remained nevertheless controversial. In order to define the utility of large doses of thiopentone, the effect of thiopentone on carbohydrate and energy metabolism of 1-year old Wistar rats was investigated in an experimental model of complete reversible ischemia followed by a recovery period. No beneficial effect of high-dose thiopentone could be demonstrated by means of changes in the carbohydrate metabolism and the energyrich compounds. There were no differences between the treated group and the spontaneous recovery group. These results are mainly confirmed by other investigators. In contrast to focal ischemia and hypoxemia beneficial effects of barbiturates can not be demonstrated after complete cerebral ischemia in experimental studies and in clinical studies as well. In conclusion there is no indication for high-dose barbiturate therapy after cardiac arrest and successfull resuscitation.

Animals↗
PubMed1987

[High-dose thiopental infusion in cerebral dysfunction following extracorporeal circulation].

Thiopentone (thp) infusion was administered to 33 patients with cerebral dysfunction or convulsions out of 2986 patients operated on via extracorporeal circulation because of valvular disease, coronary insufficiency, septum defects and intrathoracic aortic aneurysms. If phenytoin, diazepam and clonazepam proved ineffective, thp 10-15 mg/kg was injected slowly, followed by infusion of 2-4 mg/kg/h for 0.5-5 days. 9 patients died. 18 survivors had a good recovery, 6 were moderately disabled. In the survivors embolisation of particulate matter prevailed as a cause of cerebral dysfunction while in nonsurvivors prolonged pre- and postoperative hypotension was the main cause, with one patient suffering a hemispheric infarction. The amelioration of convulsions and psychosyndromes in the survivors is compatible with the known anticonvulsive effect of thp and its alleged influence on cerebral focal ischaemia. However, in protracted cerebral hypoperfusion as a cause of cerebral dysfunction no protection can be expected from thp. The known effects of barbiturates do not justify the use of these substances for the purpose of cerebral protection.

Adolescent↗
PubMed1986

[Peculiarities of juvenile vertebral fractures and dislocations of the cervical vertebrae].

In addition to diagnostic and therapeutic problems of the bony spine injuries in childhood, questions of the participation of the growth plate arise and indicate the following treatment. In the last decade we treated 23 spine injuries, resulting after fall from height. Most of the cases showed single to multiple compression fractures of the anterior spine followed in a descending frequence by the lateral compression fractures, the disconnection ot the epiphyseal plate of the axis and the actual luxation fractures with injury of the stratum germinativum. In contrast to the prognostic favourable impression fractures with a spontaneous correction, luxation fractures with or without paraplegia must be repositionned and stabilized.

Cervical Vertebrae↗
PubMed1986

The plasma dexamethasone variable in depression: test-retest studies and early biophase kinetics.

A dexamethasone suppression test (DST) was performed in 45 patients during depressive illness and after recovery. Thirty-one samples from patients in whom plasma cortisol was resistant to the suppressive action of dexamethasone contained significantly lower mean (+/- SD) concentrations of the test drug (0.63 +/- 0.39 ng/ml vs 1.10 +/- 0.53 ng/ml) during illness than after recovery and normalization of the DST. In a control group of 14 patients who exhibited adequate DST suppression during the depressive state and after recovery, the dexamethasone concentrations were unchanged (1.54 +/- 0.91 ng/ml vs. 1.30 +/- 0.92 ng/ml). To investigate further the influence of bioavailability or pharmacokinetics of the test drug on DST results, we conducted a catheter study during sleep in 11 endogenously depressed patients who received an oral 1.5 mg dose of dexamethasone at 11 p.m. The half-life of dexamethasone was markedly lower in five DST nonsuppressors (t1/2 = 160 +/- 33 minutes) than in six DST suppressors (t1/2 = 422 +/- 172 minutes). These preliminary results indicate that metabolism of dexamethasone should be controlled in studies evaluating the clinical utility of the DST.

Adult↗
PubMed1986

[The history of anesthesia at the Heidelberg University].

An account is given on the development of general anaesthesia at the university clinics of Heidelberg. During the last century mainly chloroform was employed for general anaesthesia. Important events were the first demonstration of Koller's local anaesthesia in the eye in 1884, the first intubation for anaesthesia in Heidelberg, performed by F. Kuhn of Kassel and the development by M. Neu of a rotameter apparatus for nitrous oxide/oxygen anaesthesia in 1910. From 1932 on the surgeon M. Kirschner advanced the methods of high pressure infiltration for regional anaesthesia and segmental hypobaric spinal anaesthesia. In 1951 K. H. Bauer requested R. Frey to set up an "anaesthesia squad" consisting of 2 physicians and 3 nurses to become the nucleus of today's Institute of Anaesthesiology, with O. H. Just as its first professor and chairman.

Anesthesia↗
PubMed1985

Opioid activities of human beta-casomorphins.

Opioid activities of human beta-casomorphin-4, -5, -7 and -8 and, for comparison, of the corresponding bovine beta-casomorphins were studied in the guinea-pig ileum preparation. Binding parameters, i.e. KD-values and binding site concentrations, for the interaction of human and bovine beta-casomorphins with opioid receptors in rat brain homogenates were determined in inhibition experiments, using [3H]-(D-Ala2, MePhe4, Gly-ol5)enkephalin, [3H]-(D-Ala2, D-Leu5)enkephalin and [3H]ethylketazocin as mu-, delta- and kappa-opioid receptor ligands. Analysis of binding data was performed using a non-linear curve fitting program. All beta-casomorphins examined displayed opioid activity. The affinity was highest for mu-receptors, less so for delta-receptors and lowest for kappa-receptors. It is suggested that human beta-casomorphins might play a role as "food hormones".

Animals↗
PubMed1984

[The use of neuroleptanesthesia in adenotonsillectomy in children].

Two groups of 100 children each who underwent adenoidectomy and/or tonsillectomy were anaesthetised by halothane 1% or by a neuroleptic technique (NLA) using fentanyl 0.0025 mg/kg and droperidol 0.125 mg/kg as a fixed combination (Thalamonal). Both techniques were supplemented with nitrous oxide/oxygen 4/2 l. All children were premedicated with atropine 0.015 mg/kg, fentanyl 0.0025 mg/kg and droperidol 0.125 mg/kg i.m. Quality of premedication and postoperative behaviour and analgesia were assessed by standardised criteria. 93% of the patients arrived at the theatre sleeping or detached, 75% showed almost no reactions to venipuncture. Heart rate during surgery in both groups increased by 13%, mean arterial blood pressure in the NLA group increased by 9% and in the halothane group dropped by 5%. Postoperatively blood pressure in NLA patients returned to normal, while in the halothane group there was a transient rise by 10%. Protective reflexes and consciousness were restored in the NLA group earlier. After halothane, stridor occurred in eight cases upon extubation. Postoperative analgesia scores in NLA patients were double those in the halothane group. Moderate metabolic acidosis and slight hypercapnia were postoperatively present in both groups twice. Modified neuroleptanaesthesia proved equal to halothane anaesthesia for ENT surgery. No respiratory depression was seen. Advantages like uncomplicated quick recovery and protracted postoperative analgesia are opposed by disadvantages like inferior vegetative blockade and inferior pharmacokinetics. Close postoperative supervision in a recovery room is a prerequisite to using this NLA technique.

Adenoidectomy↗
PubMed1984

[Monitoring neuromuscular function in the operating theater].

The advantages of monitoring neuromuscular blockade during anaesthesia and intensive care by electromyography or mechanomyography are reviewed. Correlations between clinical symptoms, monitoring parameters and percentage of receptor occupation are established. Single twitch, train of four and tetanic stimulation of motor nerves are described in detail and their relative indications discussed. It is pointed out, that neuromuscular transmission can be considered to be unimpaired, if single twitch responses equal 100% of preblock values and train of four ratios achieve 0.7. Especially under conditions of hypothermia, acid-base disturbances or side effects of drugs other than muscle relaxants monitoring of neuromuscular transmission is superior to simple clinical judgment.

Anesthesia↗
PubMed1984

Hazards of high dose barbiturate therapy in head-injury patients.

Despite of controversial findings, High-Dose-Barbiturate Therapy is advocated by many authors for treatment of postischemic/anoxic encephalopathy and head trauma with elevated intracranial pressure. The adverse effects to thiopentone are analyzed in a retrospective study including 30 patients treated by high-dose thiopentone for raised intracranial pressure after severe head injury. The pathophysiology and occurrence of clinical complications in many systems of the organism are illustrated. The specific prevention measures and the extended monitoring of barbiturate-treated patients are described. Considering the high incidence of clinical complications the indication for HDBT has to be reevaluated.

Cardiovascular System↗
PubMed1983

beta-Endorphin immunoreactive materials in human plasma determined by a multiple radioimmunoassay system.

Extracts of plasma obtained from adult humans before and immediately after physical stress were subjected to high pressure liquid chromatography (HPLC); extracts or HPLC fractions, resp., were analysed for the presence of human beta-endorphin (beta H-endorphin) or fragments thereof by several radioimmunoassays using antibodies directed against the C-terminus and two "middle" regions of beta H-endorphin. Using an antibody ("Don Antonio") apparently directed against a beta H-endorphin fragment including positions 17 to 22 or somewhat adjacent regions, concentrations of beta H-endorphin immunoreactivity were found to be in the well-known range under normal conditions and to increase after physical stress. However, only a minor portion of this material proved to be identical with beta H-endorphin, whereas the major portion behaved like a smaller fragment thereof. In addition, high amounts of an immunoreactive material obviously containing a C-terminal sequence of beta H-endorphin were found, indicating the presence of an immunologically relevant beta H-endorphin fragment in the plasma.

Adult↗
PubMed1982

[Influence of pancuronium bromide on spontaneous intestinal motility in the dog (author's transl)].

Eight beagle dogs were anaesthetized with 1-methadone and nitrous oxide under controlled ventilation. By means of previously implanted strain gauges circular and longitudinal contractions of ileum colon were recorded for 60 min before and 60 min following injection of pancuronium bromide (pcb) 0.08 mg/kg KG I.V. The areas under the contraction curves before and following injection were summed to yield two respective motility indices (dimension N. sec). These indices for circular and longitudinal musculature in the ileum were 14,876 +/- 7,977 and 6,825 +/- 3,172 before and 12,162 +/- 7,772 and 12,565 +/- 5,538 after pcb. For circular and longitudinal colonic musculature they were 10,244 +/- 2,643 and 15,542 +/- 2,460 before and 10,175 +/- 7,030 and 19,825 +/- 10,617 after PCB. The differences were not statistically significant. It is concluded, that pancuronium bromide had no demonstrable effect on spontaneous jejunal and colonic motility.

Anesthesia↗
PubMed1981

Hypothalamic superfusion with histamine agonists and antagonists modifies the pressor response to hypothalamic stimulation.

The posterior hypothalamus of anaesthetized cats were superfused with CSF through a push-pull cannula and electrically stimulated with its tip. Hypothalamic stimulation elicited a pressor response. Superfusion of the hypothalamus with histamine-containing CSF elicited a concentration-dependent enhancement of the pressor response. The enhancing effect of histamine was abolished, when the hypothalamus was pre-superfused with metiamide, whereas pre-superfusion with mepyramine only slightly inhibited the effect of histamine. Hypothalamic superfusion with dimaprit caused a concentration-dependent increase in the pressor response. The effect of dimaprit was abolished by pre-superfusion of the hypothalamus with metiamide, but it was not affected by pre-superfusion with mepyramine. Superfusion of the hypothalamus with 2-methylhistamine did not affect the pressor response. It is concluded that histamine increases the pressor response to hypothalamic stimulation. The enhancing effect of histamine is mainly due to its action on H2-receptors of the posterior hypothalamus.

Animals↗