PubMed Health⌕ Search

Biomedical subjects

D Moskopp

Publications and source records attributed to D Moskopp.

At least 37 records · Page 2Linked to original sources
PubMed1996

Repetitive hypoxic exposure of brain slices and electrophysiological responses as an experimental model for investigation of cerebroprotective measurements.

An in vitro hippocampal (CA 1 region, guinea pig) slice technique using repeated hypoxia was employed to model electrophysiological changes (DC-potentials and evoked potentials (EP) by stimulation of Schaffer-collaterals) occurring in the hypoxic CA1 pyramidal layer. A standardized neuronal response under repeated hypoxic conditions was observed in this model, consisting of disappearance of EP and a trend towards partially reversible, but progressive synaptic failure subsequent anoxic depolarisation (AD). Slices treated with the calcium antagonist nimodipine showed a prolongation of AD latency between the first and following hypoxias. So it seems possible to simulate hypoxic lesions of the brain tissue by using this in vitro slice model.

Animals↗
PubMed1995

Changes of extracellular calcium concentration induced by application of excitatory amino acids in the human neocortex in vitro.

The influence of the glutamate subreceptor agonists N-methyl-D-aspartate (NMDA) and alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) on cortical field potentials and on changes in extracellular free calcium concentration ([Ca2+]o) was tested on human neocortical slices (eleven from nine different patients). The tissue used was a small portion of that which is normally removed for the treatment of a brain tumor. [Ca2+]o and field potentials were measured by Ca(2+)-selective microelectrodes. Local pressure-microejection of NMDA (100 mumol/l)- and AMPA (1 mmol/l)-induced negative field potentials with maximal amplitudes of 0.9 +/- 0.1 mV (11 slices, mean +/- S.E.M.) and 1.0 +/- 0.1 mV (nine slices), respectively. The negative field potentials induced by NMDA were accompanied by monophasic decreases of [Ca2+]o (0.8 +/- 0.1 mmol/l, nine slices). AMPA elicited no (three slices) or only minor decreases of [Ca2+]o (0.2 +/- 0.1 mmol/l, five slices). The responses to the glutamate subreceptor agonists NMDA and AMPA were reversibly depressed by adding their specific antagonists DL-2-amino-5-phosphonovalerate (APV, 100 mumol/l, six slices) and 6-cyano-7-nitroquinoxalin-2,3-dion (CNQX, 5 mumol/l, four slices), respectively. The results correspond to findings in animal experiments and are consistent with the interpretation that in the human neocortex the Ca2+ permeability of channels gated by NMDA is higher than those gated by AMPA.

2-Amino-5-phosphonovalerate↗
PubMed1995

Problems of the Glasgow Coma Scale with early intubated patients.

The Glasgow Coma Scale is probably the most common grading scale in neurotraumatology all over the world. Its validity concerning severity and prognosis of the injury has been established in the Anglo-American literature. Data derived from the German rescue system, however is different from the Anglo-American in some respects. The analysis of a well-defined group of German trauma patients with moderate and severe head injuries (n = 299) shows that low Glasgow Coma Scores (GCS 3-6) established during the first two posttraumatic days must not correspond directly to the outcome after one year. Especially for the best Glasgow Coma Score during the day after the injury, GCS 4 had a poorer collective long-term prognosis than GCS 3. Therefore, German data from head injury studies based on the Glasgow Coma Scoring are difficult to compare to those cited in the Anglo-American literature. Any statistical analysis of a so called "ranking scale" which does not satisfy its own claims under special conditions is difficult.

Brain Injuries↗
PubMed1995

["I x-ray, you x-ray..." A comparative study of eponymous verbs on the occasion of the 100th anniversary of the discovery of roentgen rays].

Eponyms are derived from the name of a person. Eponymic verbs are rare compared to eponymic nouns and adjectives. The German Duden dictionary lists eponymic derivatives from the following persons: Amerigo (Vespucci), Bal(1)horn, Beckmesser, Boycott, Faraday, Galvani, Guillotin, Lumbeck, Lynch, Mendel, Morse, Pasteur und Roentgen. Only the verb "to roentgen" is formally identical to the name Roentgen. A computerized analysis of a newspaper that represents standard German (Frankfurter Allgemeine Zeitung from January 1, 1993 through March 7, 1995) proves that "to roentgen" (19x) ranges five in frequency of eponymic verbs of contemporary German-behind to boycott (363x), to ballhornize (33x), to lynch (30x), to americanize (29x).

Eponyms↗
PubMed1994

Footballs and the principle of intracranial compliance.

An easy to illustrate relationship between intracranial volume and intracranial pressure is proposed: Between the bubble and the leather of a slitted football an usual epidural pressure probe is introduced. By successively inflating the ball with a pump, the exponential increment of pressure can be demonstrated.

Brain↗
PubMed1994

Increased intracranial pressure and cardiac arrest after heart transplantation. What about the Cushing response in a denervated heart? Case report.

A 13-year-old boy suffered cerebrovascular complications after heart transplantation (ischemic mass effect in the posterior cranial fossa). He had to be resuscitated from cardiac arrest with coma. After a modified cerebellar hemispherectomy the course was favorable.--The most conclusive explanation for the acute event is that a Cushing response was preserved even in the presumably denervated heart.

Adolescent↗
PubMed1994

Successful long-term course after heart transplantation for anthracycline cardiomyopathy in a young boy despite neurological complications.

A now 14-year-old boy underwent orthotopic heart transplantation at the age of 13 for anthracycline cardiomyopathy which was a sequela of polychemotherapy for embryonal teratocarcinoma at the age of 1 year. Despite perioperative cerebellar infarction with signs of herniation which required emergency right cerebellar hemispherectomy the long-term course after 18 months turned out to be favorable with complete medical and psychosocial rehabilitation.

Adolescent↗
PubMed1994

"Ultrahigh" dexamethasone in acute brain injury. Results from a prospective randomized double-blind multicenter trial (GUDHIS). German Ultrahigh Dexamethasone Head Injury Study Group.

In a prospective randomized double-blind multicenter trial, the efficacy and safety of a 51-hour ultra-high intravenous dexamethasone dosing regimen was investigated in patients with moderate and severe head injury. 300 patients between 15 and 55 years of age were randomized to receive either placebo or dexamethasone: 500 mg intravenous infusion within 3 h after trauma initially, followed by 200 mg after 3 h, thereafter 8 times 200 mg at 6 hourly intervals, resulting in a total administered dose of 2,3 g in 51 hours. Primary end points for assessment of efficacy were: Modified Glasgow Coma Scale (grading 3-16) on Day 5, modified Glasgow Outcome Scale (grading 1-6) 10-14 months after injury, and the time interval until consciousness improved above a level of modified GCS > or = 8. Secondary endpoints were CT results and neurological and laboratory data. The two groups were well matched with respect to important prognostic variables, such as age, severity of trauma, and interval between trauma and application of the drug. 269 patients (89.7%) were available for final examination after 10-14 months. Results were surprisingly favourable in both groups: Lethality in the dexamethasone and placebo group was 14.3 and 15.4%, respectively, and 61.7 and 57.4%, respectively, achieved social and professional rehabilitation after 10-14 months (outcome scale 6). No statistical difference was seen between the dexamethasone and the placebo group in any of the primary end points of efficacy and safety (incidence of upper gastrointestinal bleeding, infection, and thrombosis).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

How many "moles" of glucocorticoids?

The entries for i.v. dexamethasone in the German National Formulary are inconsistent and can lead to differences of about 25% in calculating the dosage on a molar basis. The authors recommend a standardization of declarations of the contents of i.v. glucocorticoids.

Dexamethasone↗
PubMed1992

[Effects of nimodipine in experimental permanent focal cerebral ischemia].

In a controlled double blind experiment the influence of a continuous i.v. infusion of Nimodipine (1 microgram kg-1 min-1) upon infarct size, histopathology and neurological outcome in rats with permanent middle cerebral artery (MCA) occlusion was examined. The infusion was started 20 min. before the induction of ischemia and continued 4 hours thereafter. The nimodipine treated animals were subdivided into hypotensive (MABP lower than 85 mmHG for more than 5 minutes after arterial occlusion) and normotensive groups. Infarction size, documented by TTC, H&E and Nissl staining was significantly smaller (p less than 0.001) in nimodipine normtonic rats than the lesions in placebo and saline treated rats, as well as compared with hypotonic nimodipine animals (largest infarction). These differences were found to be entirely at the expense of the cortical (frontoparietal) component of the lesion, suggesting "penumbra" action of the drug. Moreover, nimodipine normotonic rats displayed lower cortical neuronal injury in the periinfarct zone. These findings were corroborated by corresponding better neurological scores. Our results indicate that nimodipine is effective in reducing focal cerebral ischemia, provided the MABP is maintained higher than 85 mmHg.

Animals↗
PubMed1992

[Total intravenous anesthesia using propofol and alfentanil as compared to combined inhalation anesthesia reduces the flow velocity in the middle cerebral artery. A Doppler sonographic study].

Anesthesia for craniotomies should guarantee hemodynamic stability, preservation of cerebral autoregulation, and rapid postoperative recovery of consciousness. Increases in intracranial pressure (ICP) and postoperative respiratory depression should be avoided. Combined anesthesia (KA) with N2O and volatile anesthetics may increase cerebral blood flow (CBF), ICP, and cerebral oxygen consumption. According to recent studies, total intravenous anesthesia (TIVA) with propofol and alfentanil seems to best fulfill the requirements. Using transcranial Doppler sonography (TCD) (TC2-64, EME), we studied the influence of TIVA and KA under normo- and hyperventilation on the blood flow velocity (BFV) and pulsatility of the middle cerebral artery (MCA). METHODS. Two groups of 10 patients each undergoing craniotomy were investigated. Systolic and mean BFV, pulsatility index, mean arterial blood pressure, heart rate, and arterial CO2 tension were measured at four time intervals: (1) preoperatively; (2) 15 min after anesthesia induction under normoventilation, preoperatively; (3) 25 min after anesthesia induction under hyperventilation, preoperatively; and (4) 6 h postoperatively. The patients were premedicated with flunitrazepam 1 mg PO. TIVA was induced with 60 mg propofol, 1 mg alfentanil, and 6 mg vecuronium; simultaneously infusions of propofol (15 mg/min) and alfentanil (0.3 mg/min) were started and were maintained until the dura was completely opened. The infusion rates were then reduced to 6 mg/min propofol until skin suturing and 0.1 mg/min alfentanil until dural suturing was completed. Patients were ventilated with O2/air (fiO2 = 0.5). In the KA group anesthesia was induced with 4-6 mg/kg thiopental, 0.15 mg fentanyl, and 6 mg vecuronium and maintained with boluses of fentanyl, N2O (fiO2 = 0.5), and isoflurane (1.3 MAC). The time course is illustrated in Figs. 1 and 2 and the results are shown in Tables 1 and 2. They were tested using a one-factor analysis of variance and the Kruskal-Wallis range test. RESULTS. There was a significant decrease in systolic and mean BFV combined with an increase in pulsatility index after induction of TIVA, while KA induction effected no significant change in cerebral hemodynamics. The subsequent hyperventilation caused a similar decrease in mean BFV and increase in pulsatility index in both groups. CONCLUSION. Using the assumption that the diameter of the MCA is nearly constant, the reduction in BFV associated with an increase in pulsatility during TIVA is explainable as a decrease in CBF. By having a comparable influence on hemodynamics, the reduction in CBF with increase in cerebral vascular resistance seems to make TIVA the more advantageous anesthesia technique for patients with reduced intracranial compliance.

Adult↗
PubMed1992

[Is there an unusual incidence of the manifestation of intracranial angiomas in pregnancy? Risk assessment based on 17,733 patients over 10 years].

From 1979-1988, 134 inpatients (m:f = 80:54) were treated because of an intracranial angioma (AVM). The male/female ratio was 3/2 in general as well as during the "reproductive age" (15-45 yrs). In 6 patients (20-27 yrs; grav 2/para 1: n = 3; grav 1/para 0: n = 3) the AVM became symptomatic during pregnancy (n = 4: 23-33 gestational week) or at birth (n = 2). In the group of the presently non-pregnant women (n = 40) 47 uncomplicated deliveries had occurred years before. We conclude that the available data neither allow us to reject nor to confirm the hypothesis that pregnancy and/or delivery influence the manifestation of cerebral AVMs. The reasons for this dilemma of epidemiology are discussed.

Adolescent↗
PubMed1991

Barbiturates in severe head injuries?

Possible mechanisms for the therapeutic effects of barbituric acid derivatives in severe head injuries have been discussed for half a century. In the following, a survey of the literature, and a discussion of three controlled clinical studies available until now is presented. A proven effect in terms of a beneficial long-term outcome for all injured patients has not been established. On the other hand there might be a subgroup of patients with an intact CO2 reactivity of the brain vessels who may profit from barbiturates administered after head trauma.

Barbiturates↗
PubMed1991

The locked-in syndrome and the behaviorist epistemology of other minds.

In this paper, the problem of correct ascriptions of consciousness to patients in neurological intensive care medicine is explored as a special case of the general philosophical 'other minds problem'. It is argued that although clinical ascriptions of consciousness and coma are mostly based on behavioral evidence, a behaviorist epistemology of other minds is not likely to succeed. To illustrate this, the so-called 'total locked-in syndrome', in which preserved consciousness is combined with a total loss of motor abilities due to a lower ventral brain stem lesion, is presented as a touchstone for behaviorism. It is argued that this example of consciousness without behavioral expression does not disprove behaviorism specifically, but rather illustrates the need for a non-verificationist theory of other minds. It is further argued that a folk version of such a theory already underlies our factual ascriptions of consciousness in clinical contexts. Finally, a non-behaviorist theory of other minds for patients with total locked-in syndrome is outlined.

Behavior↗
PubMed1991

[The subject of death. On the current controversy about brain-oriented determination of death].

Recently new concepts of partial brain death have seriously challenged the well-established whole-brain definition of death. In the present paper, we propose a 4-level-model of death, which differentiates the levels of attribution, definition, criteria, and tests. It is argued that whole-brain concepts of death are susceptible to partial-brain oriented criticism, mainly because they do not provide a precise determination of the subject of death.

Brain↗
PubMed1990

[Perioperative prevention of thromboembolism in neurosurgery].

In neurosurgery, none of the drugs used in other specialties as prophylaxis of thrombo-embolism have found general acceptance. Certain centers reject any drug prophylaxis of thrombo-embolism. Others treat many or--with the exception of subarachnoid hemorrhage--almost all patients according to the Kakkarscheme. Many aim for an individual examination of the risk of early mobilization and, if necessary, combine mechanical and medicinal methods (Tab. 3). No center has published any systematic studies of substantial patient populations. It is not possible to draw any medico-legal conclusions from the neurosurgical literature available. The multitude of diagnostic and therapeutic regimes, sometimes accompanied by contradictory publications, means that even non-neurosurgeons regard neither the diagnosis nor the treatment of thrombo-embolisms as ideal. Even under low-dose heparinization, deep venous thromboses can occur, and it is in principle difficult to refute the contention that this fact changes nothing whatsoever for high-risk patients as far as the incidence of pulmonary embolism ot the occurrence of significant thrombo-embolic events is concerned. Cost calculations have proved that general thrombo-embolism prophylaxis is more expensive than individual thrombosis treatment as necessary (although there are statements to the contrary). It can, however, be stated that additional costs with the aim of improving or maintaining the quality of life would be economically justifiable if a preventive effect were proved. For modern neurosurgery, however, this neither holds true generally nor for a specific subgroup. The state of research would seem to suggest that a prospective, controlled study of neurosurgical patients, primarily in a relatively low-risk group, is necessary, advisable, and justifiable.

Humans↗