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Biomedical subjects

H Knoll

Publications and source records attributed to H Knoll.

13 recordsLinked to original sources
PubMed2005

[Influence of gender on the intubation conditions with rocuronium].

PURPOSE: There is increasing evidence for gender differences in the pharmacokinetics and pharmacodynamics of anaesthetic drugs and neuromuscular blocking agents, e.g. rocuronium (Roc). Females require 30% less Roc than males to achieve the same degree of neuromuscular block and onset times are shorter. However, whether this leads to an improvement of the intubation conditions in females is unclear. METHODS: After approval of the ethics committee 60 female and 60 male patients were each randomised into 2 groups to receive 0.6 mg/kg body weight Roc or 1.0 mg/kg succinylcholine (Sux; control group). Induction: thiopentone (5 mg/kg), fentanyl (3 microg/kg) then Roc (Roc groups) or Sux (Sux groups) and tracheal intubation after 60 s. Time to intubation, glottic exposure and intubating conditions were assessed. RESULTS: Men were significantly larger and heavier (p<0.001) than women, but the body mass index was comparable (ns). Number of attempts, time to intubation, and Cormack grades were comparable (ns). However, the rate of clinically acceptable intubation conditions was significantly higher in the female compared to the male Roc group: 80% vs 47%, p<0.05. The incidence of clinically acceptable intubation conditions in the female Roc and Sux groups were similar (80%). CONCLUSION: The intubation conditions after Roc were significantly better in women than in men. The differences were Roc-related and did not occur in the control groups.

Adult↗
PubMed2004

Microenvironmental differences and changes in bilayers of unilamellar vesicles probed by spectroscopic and kinetic parameters.

The UV/Vis absorption band maximum lambdamax of trans-4,4'-nitrophenylaminoazobenzene, the thermal isomerization rate constant kiso of its cis-isomer, the fluorescence intensity ratio of monomer and excimer, and the fluorescence lifetime of the excimer, respectively, of 1,3-di(1-pyrenyl)propane were determined as probes for polarity, water content, and viscosity, respectively, in unilamellar vesicles of di-n-alkyl-dimethylammonium bromides and 1,2-acyl-sn-glycero-3-phosphocholines. The dependence on vesicle size, the solvent (water or HEPES buffer/NaCl solution, each with H2O or D2O), and the temperature (20-60 degrees C) was studied. Apparent Arrhenius activation energies and kinetic solvent isotope effects (KSIE = kiso,H2O/kiso, D2O) were derived. Size and stability of the vesicles prepared by extrusion were controlled by dynamic light scattering. The probe properties clearly indicate the reversibly decreasing size of didodecyldimethylammonium bromide vesicles with increasing temperature but are insensitive against vesicles size variation in most other cases. In the temperature range of the main phase transition of the bilayers, changes of the microenvironment of the probes, and their changing position in the bilayer, respectively, are reflected by characteristic changes of their properties. Buffer/NaCl solution causes vanishing influence of the lipid chain but remaining difference between cationic and zwitterionic headgroups probed by means of kiso.

Journal Article↗
PubMed2004

Women report more pain on injection of a precurarization dose of rocuronium: a randomized, prospective, placebo-controlled trial.

BACKGROUND: The purpose of this study was to investigate whether gender influences the perception of pain on injection of rocuronium. METHODS: In this prospective, placebo-controlled trial 120 patients were randomized into four groups to receive rocuronium 0.03 mg kg(-1) (40 female and 40 male patients) or saline (20 female and 20 male patients). The incidence and severity of the injection pain after administration of the study drug was compared between female and male patients using a numerical rating scale (0-10). Signs of local irritation, i.e. erythema and thrombophlebitis, were assessed up to 48 h after surgery. RESULTS: In 26 (32.5%) of the 80 patients receiving rocuronium, pain on injection was observed. This occurred significantly more frequently in the female compared with male patients: 18 (45%) vs. eight (20%), respectively (P = 0.032). The severity was more pronounced in the women than in the men (P = 0.020). The incidence of the rocuronium-associated pain was significantly increased compared with the Saline groups (P < 0.001). After surgery no patient complained of any residual pain and no local signs were observed in any patient during the study period. CONCLUSIONS: Women experienced more pain on injection of rocuronium than men, moreover this is an additional evidence for gender-related differences in pain perception. When rocuronium is used as a precurarization agent, an analgesic pretreatment (e.g. opioids) should be considered, especially for female patients.

Adolescent↗
PubMed1993

A natural rubber drainage tube with antithrombogenic lumen surface.

A drainage tube was made by radiation vulcanization of a high polymeric substance based on natural rubber elastomers. Pentosan polysulphate sodium bound to a carrier substance (synthetic type 4A or 13X zeolite) was incorporated in the drainage tube which was then tested for its anticoagulant properties during perfusion with Tris buffer solution, citrated plasma, and blood, resp. The amount of pentosan polysulphate sodium released from the tube walls during perfusion with human citrated plasma in an open circulatory system was sufficient to exert an anticoagulant effect on the streaming plasma. This effect was corroborated by prolonged thrombin times and by unclottability in case of recalcified plasma samples in thrombelastographic studies. The antithrombogenicity test according to Chandler in a closed circulatory system revealed thrombus formation times (TFT) of more than 24 h (control: TFT = 1-3 min in native blood).

Animals↗
PubMed1988

Studies on elastomeric materials with incorporated antithrombotics.

Antithrombotically effective drugs (heparin, pentosan polysulphate, streptokinase) were incorporated into elastomeric materials by means of zeolites as carrier. The incorporated antithrombotic agents can be delivered to the surrounding medium. These self-antithrombotic elastomers may be used as tubes to drain off body fluids (catheters, drains, etc.).

Adsorption↗