Biomedical subjects

Jens Scholz

Publications and source records attributed to Jens Scholz.

6 recordsLinked to original sources

PubMed2003

Propofol anesthesia in children does not induce sister chromatid exchanges in lymphocytes.

BACKGROUND: Propofol is frequently used for general anesthesia in children although little is known about possible genotoxic effects in humans. We investigated the formation of sister chromatid exchanges (SCE) in metaphase chromosomes of T-lymphocytes of children as a marker for possible genotoxocity following total intravenous anesthesia with propofol for minor surgical procedures. METHODS: 40 children ASA classification I-III were included (ASA I n=34, ASA II n=5, ASA III n=1) in the study. Anesthesia was induced by propofol (3mg/kg) and alfentanil. Succinylcholine or rocuronium were administered for muscle relaxation. After tracheal intubation anesthesia was maintained by continuous propofol infusion at 12 mg/(kgh). Blood samples were drawn before induction and after termination of anesthesia. Following a 72 h cell culture period, 25 T-lymphocyte metaphases per blood sample for all children were analyzed for SCE frequencies. RESULTS: Total intravenous anesthesia with propofol on children did not influence SCE rates in metaphase chromosomes of T-lymphocytes. No SCE differences could be detected between blood samples before initiation and after termination of anesthesia (Wilcoxon signed rank test). Slightly elevated SCE rates were obtained in T-lymphocytes of girls compared to boys, but these differences did not reach statistical significance. CONCLUSIONS: Propofol anesthesia under the chosen conditions did not induce the formation of SCE in children in vivo. No genotoxic effect of a short term exposure to propofol during pediatric anesthesia had been observed.

Adolescent↗

PubMed2003

Somatosensory evoked potentials as predictor of systemic inflammatory response syndrome in pigs?

OBJECTIVE: Sepsis or systemic inflammatory response syndrome (SIRS) is often associated with encephalopathy (70%), which has been described as an early symptom resulting in several diseases. The present study investigated somatosensory evoked potentials (SEP) as an indicator or even a predictor of cerebral dysfunction evaluated in an experimental model of SIRS in pigs. METHODS: Eight Göttinger minipigs were included in the study. SIRS was mediated by induction of pancreatitis due to injection (ductus pancreaticus) of 500 mg/kg sodium taurocholate and 2.5 IU/kg enterokinase. Monitored parameters were: arterial blood-central venous-pulmonary arterial pressure, and cardiac output, systemic vascular resistance, and body temperature. SEP were recorded from centroparietal vs. frontal areas after electrical stimulation of the right forepaw. RESULTS: At least 33% loss of vascular resistance from baseline (SIRS criteria) occurred in all animals within 4-18 h. Baseline recordings in all anesthetized animals indicated primary cortical responses to electrical stimuli identified by peak latencies between 15-20 ms (SEP(P15-20)). Attenuations in the amplitudes with significant median decreases of 46% were observed at least 4 h before the defined hemodynamic SIRS criteria. CONCLUSIONS: The present data show a trend for the attenuation in SEP amplitudes as an indicator of systemic inflammatory response. SEP monitoring may be a sensitive marker of developing early changes in cerebral function due to SIRS-related encephalopathy.

Analysis of Variance↗

PubMed2003

Pathophysiological changes in the elderly.

Demographic data indicate an increasing workload of geriatric anaesthesia due to advancing life expectancy and reduced thresholds for high-invasive and high-risk surgery in the elderly. Chronological and biological age may be inconsistent, and the existence of age-related changes may vary between organ systems in the same individual. Age itself is not an illness, but is the most important contributing factor for perioperative complications and adverse outcome when the overall narrowed margins of organ function reserve are transgressed during the perioperative period. Age-related changes in the cardiovascular, pulmonary, nervous, metabolic and locomotive systems that are frequently present in the elderly are discussed with regard to their potential relevance to anaesthesiology. In conclusion, listing current diagnoses will not be sufficient in the assessment of the geriatric patient because age-related changes do not necessarily manifest as pathological entities. Rather, pre-operative examination should focus on determination of individual margins of organ function reserve.

Aged↗

PubMed2003

Multicenter randomized comparison of the efficacy and safety of xenon and isoflurane in patients undergoing elective surgery.

BACKGROUND: All general anesthetics used are known to have a negative inotropic side effect. Since xenon does not have a negative inotropic effect, it could be an interesting future general anesthetic. The aim of this clinical multicenter trial was to test the hypothesis of whether recovery after xenon anesthesia is faster compared with an accepted, standardized anesthetic regimen and that it is as effective and safe. METHOD: A total of 224 patients in six centers were included in the protocol. They were randomly assigned to receive either xenon (60 +/- 5%) in oxygen or isoflurane (end-tidal concentration, 0.5%) combined with nitrous oxide (60 +/- 5%). Sufentanil (10 mcirog) was intravenously injected if indicated by defined criteria. Hemodynamic, respiratory, and recovery parameters, the amount of sufentanil, and side effects were assessed. RESULTS: The recovery parameters demonstrated a statistically significant faster recovery from xenon anesthesia when compared with isoflurane-nitrous oxide. The additional amount of sufentanil did not differ between both anesthesia regimens. Hemodynamics and respiratory parameters remained stable throughout administration of both anesthesia regimens, with advantages for the xenon group. Side effects occurred to the same extent with xenon in oxygen and isoflurane-nitrous oxide. CONCLUSION: This first randomized controlled multicenter trial on the use of xenon as an inhalational anesthetic confirms, in a large group of patients, that xenon in oxygen provides effective and safe anesthesia, with the advantage of a more rapid recovery when compared with anesthesia using isoflurane-nitrous oxide.

Adjuvants, Anesthesia↗

PubMed2003

Activation of alpha 2B-adrenoceptors mediates the cardiovascular effects of etomidate.

BACKGROUND: The intravenous anesthetic etomidate exhibits structural similarities to specific alpha2-adrenoceptor agonists of the type such as dexmedetomidine. The current study was performed to elucidate the possible interaction of etomidate with alpha2-adrenoceptors in mice lacking individual alpha2-adrenoceptor subtypes (alpha2-KO). METHODS: Sedative and cardiovascular responses to etomidate and the alpha2-agonist, dexmedetomidine, were determined in mice deficient in alpha2-receptor subtypes. Inhibition of binding of the alpha2-receptor antagonist [3H]RX821002 to recombinant alpha2-receptors by etomidate was tested in human embryonic kidney (HEK293) cells in vitro. RESULTS: In vivo, loss and recovery of the righting reflex required similar times after intraperitoneal injection of etomidate in wild-type and in alpha2A-receptor-deficient mice, indicating that the hypnotic effect of etomidate in mice does not require the alpha2A-receptor subtype. Intravenous injection of etomidate resulted in a transient increase (duration 2.4 +/- 0.2 min) in arterial blood pressure in wild-type mice (17 +/- 3 mmHg). Etomidate did not affect blood pressure in alpha2B-KO or alpha2AB-KO mice. In membranes from HEK293 cells transfected with alpha2-receptors, etomidate inhibited binding of the alpha2-antagonist, [3H]RX821002, with higher potency from alpha2B- and alpha2C-receptors than from alpha2A-receptors (Ki alpha2A 208 microm, alpha2B 26 microm, alpha2C 56 microm). In alpha2B-receptor-expressing HEK293 cells, etomidate rapidly increased phosphorylation of the extracellular signal-related kinases ERK1/2. CONCLUSIONS: These results indicate that etomidate acts as an agonist at alpha2-adrenoceptors, which appears in vivo primarily as an alpha2B-receptor-mediated increase in blood pressure. This effect of etomidate may contribute to the cardiovascular stability of patients after induction of anesthesia with etomidate.

Animals↗

PubMed2002

Evidence for a spontaneous C1840-T mutation in the RYR1 gene after DNA fingerprinting in a malignant hyperthermia susceptible family.

Malignant hyperthermia (MH) is a potentially lethal inherited pharmacogenetic syndrome due to a dysfunction of the intracellular calcium regulation of skeletal muscle following administration of volatile anaesthetics and depolarizing muscle relaxants. The ryanodine receptor of skeletal muscle (RYR1), which is an intracellular calcium release channel, has been proposed to be a candidate structure for the MH defect. In some families with a history of MH a C1840-T nucleotide exchange has been found in the RYR1 gene which cosegregates with the MH susceptible phenotype. Sixteen individuals (5 males and 11 females; age 8-68 years, 7 MH susceptible, 9 MH non-susceptible) of a family with a history of MH were screened for the C1840-T mutation in the RYR1 gene using standard methods. DNA fingerprinting was performed in order to verify the kinship. MH susceptibility was determined using the standard in vitro contracture test with halothane and caffeine. The present article describes a German MH pedigree carrying a spontaneous C1840-T mutation. The mutation was detected in one individual of the third generation. This person was classified as MH susceptible according to the in vitro contracture test protocol. None of the other family members (6 MH susceptible and 9 MH non-susceptible persons), including the parents of the child carrying the mutation, presented the C to T nucleotide exchange at position 1840.This novel observation clearly demonstrates that only the detection of the C1840-T mutation may lead to the diagnosis of MH susceptibility, but missing the mutation does not justify diagnosing a patient as non-susceptible within a single pedigree.

Adolescent↗