Inhibition of the neutrophil oxidative response by propofol: preserved in vivo function despite in vitro inhibition.

BACKGROUND AND OBJECTIVE: Propofol has been shown to inhibit a variety of functions of neutrophils in vitro, but there is a lack of in vivo data. To analyse the effects of propofol on neutrophil function in vivo we chose to investigate cataract surgery since it represents a small surgical procedure with minimal immunomodulatory effects induced by surgery. We sought to analyse any immunosuppressive effects of propofol after short-term administration in vivo in comparison to local anaesthesia as well as to in vitro effects of propofol. METHODS: The study was designed as an open randomized trial enrolling 20 patients undergoing general or local anaesthesia. The neutrophil oxidative response and propofol plasma concentration were assessed prior, during and after anaesthesia. Neutrophil function was determined flow cytometrically based on dihydrorhodamine 123 oxidation. RESULTS: Propofol concentrations which yielded a marked suppression in vitro did not alter the neutrophil oxidative response during cataract surgery in vivo. However, after local anaesthesia the neutrophil oxidative response declined to 37%, compared to the control response prior to anaesthesia. CONCLUSIONS: Although we could detect the well established suppression of neutrophil function by propofol in vitro it was not evident in vivo. This may be due to compensating effects on neutrophil function during surgery in vivo. The decline in the neutrophil oxidative response in the local anaesthesia group might be due to increased stress and catecholamine concentrations or a direct interaction of local anaesthetics with neutrophil intracellular signalling.

[Status of essential trace elements in untreated carcinomas of the head and neck]. / Status essenzieller Spurenelemente bei unbehandelten Kopf-Hals-Karzinomen.

BACKGROUND: The changed mineral status is well known in different tumor types. This phenomenon has influenced the redox potential of patients suffering from solid cancers. A prospective trial was conducted to evaluate the specifics for untreated head and neck cancer patients. MATERIAL AND METHODS: We included 100 patients with advanced squamous cell carcinoma of the head and neck region before each kind of treatment. Following serum-concentrations were measured by atom absorption spectrometry: selenium, copper, zinc, and ferrum. Additionally we evaluated the activity of glutathion peroxidase and the concentration of malondialdehyde of the serum. RESULTS: 66 % of all patients have shown a decreased serum-concentration of selenium. These patients were additionally characterized by decreased activities of endogenous glutathionperoxiase. A third of all patients had decreased zinc and iron levels. Copper was found enhanced in 30 %. In trend the malondialdehyde was increasing due to decreasing selenium levels. CONCLUSIONS: Head neck cancer patients show the same characteristic trace element status as other solid tumors: decreased selenium, zinc and iron, increased copper. The therapeutic consequences of these observations are still unclear.

Less adrenergic activation during cataract surgery with total intravenous than with local anesthesia.

BACKGROUND: Previous studies reported that, contrary to local anesthesia, cataract surgery under inhalational anesthesia is associated with substantial adrenergic activation. We tested the hypothesis that total intravenous anesthesia (TIVA) with propofol and alfentanil produces less or comparable adrenergic activation during cataract surgery than local anesthesia. METHODS: Patients were randomly assigned to peribulbar local block (n=10) or TIVA (n=10). The heart rate, blood pressure, plasma concentrations of catecholamines, cortisol, and glucose were assessed at seven pre-, intra-, and post-operative time points. RESULTS: In the patients given local anesthesia, plasma concentrations of epinephrine, norepinephrine and cortisol did not change significantly. In contrast, plasma epinephrine decreased by roughly 66% during TIVA: from 45+/-16 to 15+/-8 pg/ml. Plasma norepinephrine concentration decreased by roughly 50%, from 462+/-265 to a minimum value of 219+/-6 pg/ml and plasma cortisol concentrations decreased by roughly 61%, from 16.4 ng/ml to 6.4 ng/ml. Blood pressure and heart rates remained near baseline values during local anesthesia. In contrast, systolic blood pressure decreased by 30% and heart rate by 12 beats/min during TIVA. CONCLUSION: The presented study and available data clearly suggest that local anesthesia produces the best adrenergic and hemodynamic stability during cataract surgery. Contrary to previously reported results on inhalational anesthesia (thiopentone/enflurane), the TIVA regimen used effectively prevents the adrenergic and metabolic response during cataract surgery.

On-line coupled liquid chromatography-gas chromatography (LC-GC) and LC-LC-GC for detecting irradiation of fat-containing foods.

On-line coupled liquid chromatography-gas chromatography-flame ionisation detection (LC-GC-FID) enables efficient and unambiguous determination of irradiation for some fat-containing foods (e.g. meat). Other products, however, contain interfering components or are contaminated, e.g., with mineral oil. Since more selective detection by mass spectrometry has limited success, the determination was improved by a more selective isolation of some key components among the fat degradation products, e.g. the dienes or trienes, by LC-LC-GC-FID. Applications are shown for soup mixes, some spices, fish, and shrimps.