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Biomedical subjects

N Lehmann

Publications and source records attributed to N Lehmann.

9 recordsLinked to original sources
PubMed2006

Mediterranean diet has no effect on markers of inflammation and metabolic risk factors in patients with coronary artery disease.

OBJECTIVE: Mediterranean diet is associated with decreased levels of inflammatory markers and metabolic risk factors in epidemiologic studies and recent trials on patients with metabolic syndrome. Given the recent improvements in medical treatments, it is unclear if such beneficial effects are also present in patients with coronary artery disease (CAD). We therefore investigated the effect of Mediterranean diet on markers of inflammation and metabolic risk factors in patients with treated CAD. DESIGN: Randomized, controlled trial. SUBJECTS: A total of 101 patients (59.4+/-8.6 years, 23% female) with established and treated CAD (80% statins). INTERVENTIONS: Participants were assigned to a Mediterranean diet group (MG; n=48) with a 1-year program of 100 h of education, or to a written advice-only group (AG; n=53). Before and after intervention, we measured serum high-sensitivity C-reactive protein (hs-CRP), fibrinogen, fasting insulin, homocysteine, serum lipids and plasma fatty acids. RESULTS: The Mediterranean diet program increased the intakes of fish, fruits/vegetables and moderately of canola/olive oil and increased plasma concentrations of long-chain n-3 polyunsaturated fatty acids in the MG. Median hs-CRP and mean fibrinogen, homocysteine, fasting insulin, triglycerides and serum cholesterols remained unchanged in both groups. CONCLUSIONS: Adoption of a Mediterranean diet by patients with medically treated CAD has no effect on markers of inflammation and metabolic risk factors. SPONSORSHIP: Alfried Krupp Foundation, Essen, Germany.

Biomarkers↗
PubMed2001

Post-mortem detection and identification of sildenafil (Viagra) and its metabolites by LC/MS and LC/MS/MS.

The highly putrefied corpse of an 80-year-old man was found in the apartment which he had rented to a prostitute. A package of Viagra 25 was found beside the corpse and three tablets were missing. Autopsy revealed severe coronary artery sclerosis as well as signs of previous myocardial infarctions. For the detection and identification of sildenafil and three metabolites in urine and tissue samples, solid-phase extraction, LC/MS and MS/MS methods were developed. Blood was not available for toxicological analysis due to the putrefaction. For method development, urine from a volunteer who had ingested 25 mg sildenafil was collected over 8 h, and three metabolites were identified by MS/MS. These metabolites were also found in the victim's urine. These findings prove that sildenafil was taken some time prior to death, but the causality of sildenafil intake and fatal cardiac failure could not be proven, since no blood was available for analysis. However, the administration of sildenafil was contraindicated due to several previous myocardial infarctions.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed2000

Identification of lorazepam and sildenafil as examples for the application of LC/ionspray-MS and MS-MS with mass spectra library searching in forensic toxicology.

A mass spectra (MS) library using in-source collision induced dissociation (ESI-CID) as well as a tandem-mass spectra (MS-MS) library with product ion spectra of drugs has recently been developed with a triple-quadrupole ionspray mass spectrometer [1,2]. For the ESI-CID MS library, single-quadrupole mode and for the MS-MS library triple-quadrupole mode have been used. These mass spectra libraries were applied successfully for the general-unknown screening for drugs and metabolites in serum and urine with liquid-chromatography-mass spectrometry (LC-MS) using a PE/SCIEX API 365 with a turboionspray source. As examples, the identification of lorazepam and lorazepam-glucuronide in a serum extract and the identification of sildenafil and alkyloxidated sildenafil in urine are presented here.

Databases, Factual↗
PubMed1997

Plasma levels of immunoinhibitory cytokines interleukin-10 and transforming growth factor-beta in patients undergoing coronary artery bypass grafting.

OBJECTIVE: Cardiovascular surgery with extracorporeal circulation causes a systemic inflammatory response, which can lead to organ failure and increased postoperative morbidity. Advances in knowledge about the interactions between markers of cellular and humoral immunity involved in the inflammatory response to cardiopulmonary bypass (CPB) may reduce the deleterious effects and improve the outcome for patients undergoing cardiac surgery. METHODS: To determine the release of immunoinhibiting cytokines during CPB, we measured plasma levels of interleukin-10 (IL-10) and transforming growth factor-beta (TGF-beta) in 30 patients undergoing elective coronary artery bypass grafting. Arterial blood samples were collected at eight time points before, during and after CPB, using a standardized ELISA-technique. RESULTS: Plasma IL-10 and TGF-beta increased significantly after weaning off CPB (P < 0.05) and peaked respectively at time of skin closure (IL-10, 308 +/- 180 pg/ml; TGF-beta, 1860 +/- 906 pg/ml; mean peak +/-S.D.). Postoperatively, 6 h, IL-10 decreased to 19.8 +/- 9.8 pg/ml (P < 0.05) and TGF-beta decreased to 1133 +/- 547 pg/ml (P < 0.05). CONCLUSIONS: Both cytokines are major immunoregulatory factors with negative influence on T cell-mediated immunologic response. The significantly elevated levels at the end of CPB indicate that IL-10 and TGF-beta may be important factors of immunologic dysregulation following CPB.

Adult↗
PubMed1997

Alterations of the cytokine network in patients undergoing cardiopulmonary bypass.

Cardiovascular surgery using extracorporeal circulation causes a systemic inflammatory response which often results in severe organ dysfunction and increased postoperative mortality. Advances in knowledge about the interactions of cytokines involved in the response to cardiopulmonary bypass (CPB) may improve the outcome of patients undergoing cardiac surgery. The purpose of our study was to investigate the fluctuations in cytokine production, during and after CPB. In 24 patients undergoing elective coronary artery bypass grafting, plasma levels of interleukins IL-2, IL-6, IL-10 and IL-12, soluble IL-2-receptor (sIL-2R), and transforming growth factor-beta (TGF-beta) were measured at eight time points before, during and after CPB, using a standardized enzyme-linked immunosorbant assay technique. There was a significant increase in plasma levels of IL-10, IL-6 and TGF-beta after weaning off CPB. The IL-2 plasma levels decreased after the onset of CPB until 24 h postoperatively (p < 0.05). Concentrations of sIL-2R decreased 20 min after the start of CPB until the end of the operation (p < 0.05). In the postoperative course, sIL-2R levels increased, with peak values 48 h after the end of the surgical procedure. The IL-12 levels decreased after weaning off CPB (p < 0.05) until 6 h postoperatively. The results of our study demonstrate an intraoperative-predominant immunosuppression, followed by an early postoperative immunological activation, combined with a distinct acute phase response.

Adult↗
PubMed1979

Contractile responses to direct stimulation of frog slow muscle fibres before and after denervation.

1. The contractile responses of single slow muscle fibres were investigated under isometric conditions. The fibres were isolated from normal and denervated iliofibularis muscle of Rana temporaria. Direct stimulation was achieved by external application of electrical pulses of depolarizing solutions (40 mM K and acetylcholine 10(-6) g/ml). 2. Upon electrical stimulation normal slow fibres developed contractions whose amplitude increased steadily with the strength of the pulses. These contractions did not exceed 0.22 kg/cm2, and their rates of rise and fall were approximately 1/6 of those observed in twitch fibres. During pulses of several 100 ms duration the tension continued to rise slowly until the end of the pulses. Application of 40 mM K or acetylcholine resulted in contractures which reached maximum values of 1.71 and 1.87 kg/cm2, respectively, after less than 1 min; little relaxation occurred during the following minutes. 3. The responses of slow fibres denervated for 9--76 days differed in several respects from those of normal slow fibres. a) The contractions elicited by electrical stimulation became faster but their amplitude decreased; the relationship between tension and pulse strength remained, however, essentially unchanged. b) Small and short contractions could be observed during and at the end of stimulating current pulses. Their amplitude was independent of the amplitude and duration of the stimuli; they were blocked by tetrodotoxin and must be attributed to action potentials. c) The ability to develop and maintain tension was reduced. Maximum values of K- and acetylcholine contractures were generally only 50% of those observed in normal slow fibres. Maintenance of tension was markedly reduced in some fibres, less so in others. 4. It is concluded that incorporation of Na channels into its membrane does not transform the slow fibre into a type of fibre which resembles a twitch fibre.

Acetylcholine↗