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Biomedical subjects

D Bremerich

Publications and source records attributed to D Bremerich.

6 recordsLinked to original sources

[Isolated decrease of haptoglobin during pregnancy: diagnosis by chance or pathological? ].

Haptoglobin is an acute-phase-protein, which is important in many diseases like infections, trauma and neoplasma. An increase in haptoglobin is induced by cytocines like IL-6 und IL-1. The normal range for plasmatic haptoglobin is 50-220 mg/dl. During pregnancy the most likely diagnosis is the HELLP- Syndrome (hemolysis, elevated liver enzymes and low platelets), followed by rare diagnoses like viral hepatitis or favism. We report about a 31-year-old III-gravida 0-para at 31 weeks of gestation with a decrease of haptoglobin over a period of 6 weeks (cut off: < 13 mg/dl) and without any clinical signs of preeclampsia. Liver enzymes were constantly slightly elevated without any progress, other laboratory test results were normal. The patient had a caesarean section at 37 weeks of gestation. Serum haptoglobin returned to normal values within three days after delivery. The reason for the decrease of haptoglobin in our case remains uncertain. Further studies need to focus on the differential diagnosis of a decrease of haptoglobin as well as an isolated decrease of haptoglobin during pregnancy and on the valid ranges of the different haptoglobin subtypes.

Adult↗

Thrombin causes vascular endothelial growth factor expression in vascular smooth muscle cells: role of reactive oxygen species.

Vascular endothelial growth factor (VEGF) has been implicated in the reendothelialization of the vascular wall after balloon injury. This study investigated whether thrombin, which is formed during activation of the coagulation cascade at sites of vascular injury, upregulates VEGF expression in vascular smooth muscle cells (VSMCs). VEGF expression was assessed in native and cultured VSMCs by Northern blot analysis and reverse transcription-polymerase chain reaction and the release of VEGF protein by immunoassay. alpha-Thrombin time- and concentration-dependently increased VEGF mRNA levels, mainly that mRNA coding for the soluble splice variant VEGF(164/165), and stimulated the release of VEGF protein. These effects required the proteolytic activity of thrombin and were mimicked by a thrombin receptor activating-peptide. Upregulation of VEGF expression was also induced by conditioned medium from alpha-thrombin-stimulated VSMCs. Both the early and the delayed alpha-thrombin-induced VEGF expressions were attenuated by antioxidants and by diphenyleneiodonium. alpha-Thrombin-induced VEGF release was significantly reduced by a platelet-derived growth factor (PDGF)-, a transforming growth factor (TGF)-beta-, and a basic fibroblast growth factor (bFGF)-neutralizing antibody. Thrombin caused a redox-sensitive upregulation of expression of VEGF in VSMCs through a direct and an indirect effect, which was dependent on the endogenous formation of PDGF, TGF-beta, and bFGF. Upregulation of VEGF expression may represent an important mechanism by which the coagulation cascade contributes to the regeneration of the endothelial lining at sites of balloon injury.

Acetylcysteine↗

Respiratory effects and tolerability of Mr 2264 Cl. A new opiate partial agonist in comparison with morphine and placebo.

In this double-blind, randomised, placebo-controlled cross-over study the respiratory effects of M(r) 2264 Cl 2 x 5 mg i.v., a new partial opiate receptor agonist, were investigated and compared with the respiratory effects of morphine 2 x 10 mg i.v. and placebo. As primary end-points, the slope of the rebreathing curve (dV'/dPCO2ET) and V55 (ventilation at PCO2ET = 55 mm Hg) were determined by Read's rebreathing method. The incidence of adverse events was also documented and compared. The respiratory depression after the intravenous administration of 5 mg and 10 mg M(r) 2264 Cl was comparable to the decreased sensitivity of the respiratory centre after the 20 mg morphine i.v. In contrast to morphine, a ceiling effect of M(r) 2264 Cl was found. The tolerability of M(r) 2264 Cl was comparable to that of morphine.

Adult↗

[Effectiveness of preventing hypotension with H1/H2 antagonists before protamine administration].

BACKGROUND: This prospective randomized study was undertaken to evaluate the effects of prophylactic administration of H1/H2 receptor blockers on histamine release and hemodynamic changes after administration of protamine in two groups of patients (n = 20) undergoing elective coronary artery bypass graft surgery. PATIENTS AND METHODS: Group 1 (n = 10) patients were pretreated intravenously with 1 mg/kg ranitidine and 0.1 mg/kg dimetinden 15 min before termination of the extracorporeal circulation; group 2 patients (n = 10) received no medication. After termination of the extracorporeal circulation, heparin was neutralized by administration of 350 U/kg protamine, injected during 4 min via a peripheral vein. Hemodynamic measurements were carried out before the administration of protamine and at 1-min intervals up to 10 min after the injection. Before administration of protamine and 2, 4, 6, 8, and 10 min thereafter, plasma histamine levels were measured using central venous blood samples. RESULTS: In group 1 patients, who were treated prophylactically with H1/H2 receptor blockers, the plasma histamine concentration was 0.21 +/- 0.15 ng/ml (mean +/- SD) and reached a peak value of 0.30 +/- 0.17 ng/ml within 4 min. In group 2 patients, the plasma histamine concentration increased from 0.17 +/- 0.15 to 0.26 +/- 0.24 ng/ml after 10 min. The hemodynamic reactions were comparable in both groups (group 1: decrease in systolic arterial pressure from 118 +/- 16 to 104 +/- 15 mm Hg; group 2: from 111 +/- 19 to 108 +/- 21 mm Hg; differences statistically not significant). The Spearman rank correlation revealed no statistically significant relationship between the slight plasma histamine release and clinically severe decreases of blood pressure that were observed in single patients. CONCLUSION: Histamine release appears unlikely as the mechanism of protamine-induced hypotension. Therefore, general prophylaxis using H1/H2 receptor antagonists does not seem to be justified and cannot be recommended.

Aged↗

[Failure of relaxometry in diabetic polyneuropathy].

Disturbances of the peripheral nervous system, summarised under the term "diabetic polyneuropathy", are a well-known complication of long-term diabetes mellitus. However, there is little information about the fact that these conditions may lead to difficulties in monitoring neuromuscular blockade by peripheral nerve stimulation during general anaesthesia. We report two diabetic patients (40 resp. 62 years of age) in whom a total of four ophthalmological operations were performed under general anaesthesia. In all cases monitoring of neuromuscular transmission was attempted by stimulation of the left ulnar nerve slightly proximal to the wrist, but not even the usual calibration could be obtained in either patient. Checks confirmed that the nerve stimulator was functional and the electrodes--in all cases self-adhesive, pregelled surface electrodes--were placed correctly. In order to evaluate the hypothesis that disturbances of peripheral nerve function might be responsible, the patients were examined neurophysiologically in the postoperative period. Both patients showed severe alterations in peripheral nerve conduction: a sensory response could not be evoked in any of the extremities and the ulnar distal motor latency time was pathologically prolonged (5.4 ms in patient 1 and 4.9 ms in patient 2; normal: 1.4-4.0 ms). Therefore, in accordance with the clinical symptoms, the diagnosis of diabetic polyneuropathy was established. These cases demonstrate that severe disturbances of the peripheral nervous system may render neuromuscular monitoring impossible.

Adult↗

[Midazolam for premedication of infants. A comparison of the effect between oral and rectal administration].

Midazolam (M) has been successfully used in oral and rectal premedication of children of one to six years of age. The following study was designed to investigate the efficacy of both methods when used as premedication "on demand". 60 children (1-6 years) were randomly assigned to 0.3 mg/kg bw M orally and 0.5 mg/kg bw M rectally. Psychological, behavioural and physiological parameters were measured at special time intervals and special stressful events (separation from the mother or father, induction of anaesthesia). Rectally premedicated children were found to be better prepared concerning psychological and behavioural parameters. This can be due to the dosage as well as the faster absorption of M. In the postoperative period orally premedicated children experienced significantly more nausea and vomiting. This might be due to the preparation with saccharin, peppermint oil and ethanol. - In "premedication on demand" rectal Midazolam must be preferred to orally administered Midazolam in the preparation mentioned above.

Administration, Oral↗