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C Franssen

Publications and source records attributed to C Franssen.

9 recordsLinked to original sources
PubMed1992

The influence of different beta-blocking drugs on the peripheral circulation in Raynaud's phenomenon and in hypertension.

In a double-blind, randomized, placebo-controlled study, the authors investigated the effects of different beta-adrenoceptor blocking drugs on the peripheral circulation. A single intravenous injection of the nonselective beta-blocker propranolol (0.20 mg/kg), the beta 1-selective adrenoceptor blocker metoprolol (0.25 mg/kg), and the nonselective beta-blocker with partial agonistic activity (PAA) pindolol (0.04 mg/kg) and of placebo (saline) was given to eight patients with a primary Raynaud's phenomenon and to nine untreated patients with primary hypertension. The authors measured finger skin temperature (FST), and laser Doppler estimated finger skin blood flux (LDF) before, during, and after a standardized finger cooling test, performed 25 minutes after the administration of the drugs. In both patients groups propranolol, metoprolol, and pindolol had no significant effect on FST and LDF in the first 25 minutes after administration both in comparison to baseline value and to placebo. Also, no significant differences were found in the recoveries of FST and LDF after cold challenge between all drugs and placebo in both groups. The authors conclude that no adverse effect of any type of beta-adrenoceptor blocker in comparison to placebo could be detected after a single administration on both the baseline finger skin perfusion and the recovery after cold-induced vasoconstriction. In addition, the authors could not demonstrate a favorable effect of beta 1-selectivity or PAA in comparison to a nonselective beta-adrenoceptor blocker without PAA, in any group.

Adrenergic beta-Antagonists↗
PubMed1991

Continuous measurement of jugular venous bulb oxygen saturation in neurosurgical patients.

Monitoring cerebral oxygen availability and utilization is of the utmost importance for patients with brain insults or potentially at risk of brain oxygen deprivation. The availability of the continuous measurement of oxygen saturation in the jugular bulb questions the value of this parameter as an indicator of brain oxygenation. This article reviews the theoretical background and the practical aspects of this monitoring. It describes its possible applications to neurosurgical patients in the operating theater as well as in the intensive therapy unit. Finally, it comments on its main limitations which could impede an extensive utilization in clinical practice.

Brain↗
PubMed1991

[Value of arteriovenous oxygen difference in the therapeutic approach of post-traumatic intracranial hypertension].

Elevated intracranial pressure (ICP) is undoubtedly a determinant factor of outcome in severe head injured patient. Until now, medical treatment of elevated ICP in diffuse brain lesions consisted of hyperventilation, CSF drainage, mannitol and barbiturates without accurate selection criteria. In fact, in comatose patients, the cerebral blood flow (CBF) can vary independently of the cerebral metabolic rate of oxygen (CMRO2) which is typically reduced. The venous oxygen saturation (SjO2) measured in the jugular bulb and the arterial-jugular oxygen difference (ajDO2) can be used for more appropriately selecting therapeutic measures. According to the following equation: CMRO2 = CBF x ajDO2, the measurement of the changes in ajDO2 might serve as an indicator of CBF adequacy, out of the presence of cerebral ischemia. A decreased ajDO2 suggests that CBF is excessive for cerebral metabolic requirements and an elevated ajDO2 indicates a decreased CBF. Consequently, treatment of elevated ICP in the presence of a low ajDO2 should be more oriented towards moderate hyperventilation and administration of metabolic depressive agents with maintenance of normal arterial blood pressure. Conversely, in case of high ajDO2, ICP control should aim to increase CBF by maintaining normocapnia, improving hemodynamic status or reducing extravascular volume accordingly.

Adult↗
PubMed1990

DNA strand breaks in human leukocytes induced by chemotherapy and total body irradiation.

The occurrence of DNA strand breaks and/or DNA alkali-labile sites in peripheral blood leucocytes was demonstrated ex vivo in three patients during and after bone marrow ablative chemotherapy and total body irradiation (TBI) with use of fluorometric analysis of the DNA unwinding rate in alkaline solution (FADU assay). DNA damage was apparent after cyclophosphamide administration and after TBI, related to the amount of the applied dose. In vivo repair occurred within 24 hours, although not to pretreatment values. Demethoxydaunorubicin and busulfan at the dosages used did not induce measurable DNA strand breaks. The experiences described may be developed further to study ex vivo the occurrence of DNA lesions in patients during and after anticancer treatment. Such studies may be of value in comparing the DNA damaging potential of different chemotherapeutic or radiotherapeutic regimens and as a biological assessment of DNA damage after nuclear casualties in cases where the dose is greater than 1-2 Gy and measurement can be made within due time after the ionizing exposure.

Adult↗
PubMed1990

Evidence of in vivo free radical generation by spin trapping with alpha-phenyl N-tert-butyl nitrone during ischemia/reperfusion in rabbit kidneys.

By using alpha-phenyl N-tert-butyl nitrone (PBN) as spin trap molecule and the electron paramagnetic resonance (EPR) technique, we obtained the first direct evidence of in vivo intervention of free radicals during an ischemia (50 minutes) reperfusion phenomenon in kidney of an intact rabbit. An EPR signal (triplet of doublets) characterized by coupling constants aN = 14.75-15 G and aH beta = 2.5-3 G was detected in blood samples. The signal was consistent with a nitroxyl-radical adduct resulting from the spin trapping by PBN of either oxygen-or carbon-centered radicals. Control experiments indicated that the EPR signal was not due to a toxic effect of the spin trap molecule.

Animals↗
PubMed1989

Improved outcome prediction based on CSF extrapolated creatine kinase BB isoenzyme activity and other risk factors in severe head injury.

The present study of 43 patients with severe head injury shows that outcome prediction can be markedly improved by combining an appropriate marker of the degree of initial brain damage and other risk factors. The patients were classified into three groups according to their actual outcome after 6 months: death (22 patients); persistent vegetative state or severe disability (eight patients); and moderate disability or good recovery (13 patients). By applying stepwise logistic discriminant analysis to the patients' data, five significant risk factors were selected: degree of neurological damage assessed by cerebrospinal fluid (CSF) extrapolated creatine kinase BB isoenzyme activity, Glasgow-Liège Coma Scale score, age, incidence of thoracic injury, and intracranial pressure (ICP). Extrapolated creatine kinase BB activity had the highest prognostic ability (67%). Uncontrollable elevated ICP proved to be systematically associated with death, whereas its absence was not necessarily indicative of a favorable outcome. The combination of the five variables yielded a total prognostic efficiency of 91%. The percentages of correctly predicted patients for the three outcome groups were, respectively, 100%, 50%, and 100%. Thus, half of the persistently vegetative and severely disabled patients were identified by the selected factors.

Adolescent↗
PubMed1988

[Brain death].

Explore the source record for details and available documents.

Brain Death↗
PubMedDate not supplied

[Oxygen metabolism and toxicity in the phenomenon of ischemia-reperfusion].

One of the major cause of human disease results from the compromise of blood flow and oxygen delivery to tissues. Ischemia phenomenon is defined as blood flow that is inadequate to maintain normal tissue function. Prolonged ischemia ultimately results in irreversible changes in cell metabolism and cell death. Historically, it was felt that if ischemia results in altered cell function and injury, then reoxygenation or reperfusion leading to a restoration of a normal blood flow was expected to have a beneficial effect and promote salvage of tissue depending on the extent of ischemia. Recent studies have, however, revealed that reoxygenation leads to an oxygen metabolism resulting in the generation of active and toxic oxygen intermediates (free radicals) which play an important role in the pathophysiology of reperfusion injury.

Antioxidants↗