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Biomedical subjects

H Burgmann

Publications and source records attributed to H Burgmann.

At least 73 records · Page 4Linked to original sources
PubMed1995

Serum concentrations of MIP-1 alpha and interleukin-8 in patients suffering from acute Plasmodium falciparum malaria.

The chemokines are a superfamily of small proteins secreted primarily by leukocytes and related by a conserved four-cystein motif. In the present study we investigated the serum levels of macrophage inflammatory protein 1 alpha (MIP-1 alpha) and interleukin-8 (IL-8). MIP-1 alpha is a neutrophil chemotactic protein important in acute and chronic inflammation. Recent studies demonstrated that MIP-1 alpha may also act as potent inhibitor of hemopoetic stem cell proliferation, which may be important in the development of prolonged anemia in patients suffering from Plasmodium falciparum malaria. IL-8 serum concentrations correlate with severity and outcome of infectious diseases. Moreover, recent reports indicate that IL-8 plays a major role in fatal gram-negative sepsis. It was the aim of this study to investigate the time course of MIP-1 alpha and IL-8 concentrations in patients suffering from acute P. falciparum infection. Blood samples of 20 patients suffering from severe P. falciparum malaria were investigated. MIP-1 alpha and IL-8 concentrations were determined using ELISA technique at admission, on Days 7, 14, 21, and 28. Maximal concentrations of MIP-1 alpha and IL-8 were found on Day 14, at a time when parasites were not detected in the smears. The serum levels of IL-8 on the day of admission were correlated to the parasite count. No correlation was seen between the hematokrit values and the MIP-1 alpha concentrations at any time.

Adolescent↗
PubMed1995

Small bowel tissue high-energy phosphate regeneration after 7 hr of cold ischemic storage: comparison of University of Wisconsin and Eurocollins solutions.

As adenine nucleotide content has been shown to correlate with post-transplant function of livers and hearts, it was the aim of our study to investigate the regeneration of rat small bowel tissue high-energy phosphates after 7 hr of cold storage followed by incubation of everted small bowel sacs in normothermic oxygenated KHB for 1 hr. We compared the University of Wisconsin (UW) and the Eurocollins (EC) solutions. Krebs-Henseleit-bicarbonate buffer (KHB) was used to point out the effect of simple cold ischemic storage. After 7 hr of cold storage only small bowel stored in UW and EC solutions retained the capacity for almost total regeneration of ATP necessary for optimal posttransplant function, whereas in the KHB group we found only minimal regeneration. A similar pattern was found for the energy charge. These data support the superiority of UW and EC solutions over simple cold storage in KHB for preservation of small bowel.

Adenosine↗
PubMed1995

Decreased serum levels of TGF-beta in patients with acute Plasmodium falciparum malaria.

Apart from cellular immunity and immunopathology, various cytokines have been implicated in malaria-associated immunosuppression. In this study, serum levels of transforming growth factor-beta (TGF-beta) were determined with an enzyme-linked immunosorbent assay in 37 patients with acute Plasmodium falciparum malaria prior to, during, and after therapy and in 17 healthy controls in Bangkok, Thailand. Patients were treated with artesunate and mefloquine. TGF-beta serum levels were found decreased prior to treatment (14 +/- 11 pg/ml versus 63 +/- 15 pg/ml in healthy controls; P < 0.05). The serum concentrations of TGF-beta increased after initiation of treatment and were within normal range on day 21. Serum levels of both tumor necrosis factor-alpha (TNF-alpha) and soluble TNF-receptor 55 kDa were inversely correlated to serum levels of TGF-beta (r = -0.667 and r = -0.592, n = 37; respectively, P < 0.05 for both). No correlation between parasitemia and serum levels of TGF-beta could be found. The results are compatible with a decreased production and release, an enhanced clearance or utilization, or tissue accumulation of TGF-beta in acute P. falciparum malaria.

Adolescent↗
PubMed1995

[Biochemistry, molecular mechanism of action and biological effects of endotoxin].

This review is a brief attempt at providing an overview of a subject of enormous complexity-endotoxins and the mediators associated with its biological effects. More specifically it deals with biochemistry and biology of endotoxin, detection of endotoxin with the Limulus amebocyte lysate test, the molecular mechanisms and biological effects, and in the last part with future aspects of therapeutical strategies. It seems certain that the subject will become even more complex and possibly controversial as scientific knowledge further involves. However, because of the high mortality rate of patients suffering from gram-negative sepsis all efforts have to be made to find effective therapeutical strategies.

Animals↗
PubMed1994

Administration of atracurium during reperfusion of rat livers after 21 h of cold ischaemic storage in different solutions.

The pharmacokinetics of atracurium are not altered by impaired hepatic function. The drug is therefore used widely in liver transplant patients. In previous work on the hepatotoxic effects of atracurium in an isolated, perfused rat liver model, we could not detect biochemical (release of lactate dehydrogenase or aspartate aminotransferase) or histological evidence of liver cell damage, except a reduction in hepatic tissue ATP content. In the present study, rat livers were reperfused with Krebs-Henseleit bicarbonate buffer with or without atracurium after 21 h of cold ischaemic storage in University of Wisconsin (UW), Bretschneider's HTK or Euro-Collins solution. UW-protected livers showed a complete restoration of ATP, total adenine nucleotides and energy charge during reperfusion, but the addition of atracurium diminished the regeneration capacity to about 50%. The energy charge (an index for determination of liver viability) was also reduced markedly.

Adenine Nucleotides↗
PubMed1994

Influence of incubated atracurium on rat liver function.

Degradation of atracurium by Hofmann elimination and ester hydrolysis depends mainly on pH and temperature and is said to be independent of liver and kidney function. Consequently atracurium is used widely in patients with liver failure. However, there is evidence that incubation of atracurium at 37 degrees C and pH 8 leads to leakage of LDH from hepatocyte cell cultures. We have tested the hepatotoxic effects of incubated atracurium in an isolated perfused rat liver model. After equilibration, atracurium 2010 mumol ml-1 (preincubated at pH 8 and 37 degrees C for 120 min) was administered over a period of 10 min followed by perfusion of Krebs-Henseleit bicarbonate buffer for 60 min. We found that incubation resulted in considerable degradation of atracurium and formation of laudanosine. Administration of incubated atracurium did not produce either biochemical or morphological damage to liver cells, but caused considerable increase in bile flow. We conclude that administration of preincubated atracurium did not produce impairment of liver cell function. The increase in bile flow could be beneficial if it occurs clinically.

Animals↗
PubMed1993

Proton spin-lattice relaxation time as liver transplantation graft viability parameter.

In this study proton NMR T1 of stored rat liver grafts was investigated and correlated with other viability parameters. Five different storage solutions were used and T1 as well as overall tissue water content, bile flow, and energy charge were determined after various periods of cold storage (1 to 48 hr). A good correlation between T1 and tissue water content was detected, suggesting the possible use of this relaxation time parameter as liver graft viability parameter in a combined protocol of rapid viability assays for human liver transplantation surgery.

Adenosine↗
PubMed1993

Proton spin-spin relaxation times as liver transplantation graft viability parameter.

In this study, spin-spin relaxation time T2 of stored rat liver grafts was investigated and correlated with other viability parameters. Five different storage solutions were applied and T2 as well as overall tissue water content, bile flow, and energy charge were determined for increasing durations of cold storage (1-48 hr). Good correlation between T2 and tissue water content was detected. In a subset of experiments, dealing with additional warm ischemia after cold storage, the relative increase of T2 and energy charge showed a very good correlation. The results suggest the possible use of relaxation time parameters as liver graft viability parameters in a combined protocol of rapid viability assays for human liver transplantation surgery.

Animals↗
PubMed1993

Induction of the release of prostaglandin E2 from polymorphonuclear neutrophil granulocytes by Bacteroides fragilis: its possible role in the pathogenesis of mixed infections.

The presence of anaerobic bacteria, especially of Bacteroides (B.) fragilis, in abdominal abscesses, infected decubitus ulcera, and the infected foot of diabetic patients is well documented. The importance, however, of these microorganisms in the pathogenesis of deep tissue infections has still to be evaluated. Therefore, the aim of this study was to evaluate the potency of B. fragilis as compared to aerobic bacteria widely known for causing inflammation, in inducing the release of prostaglandin E2 from polymorphonuclear granulocytes. Prostaglandin E2 is a potent vasodilator and contributes to edema and erythema, which are part of the inflammatory response. Furthermore, the cAMP-content of the neutrophils was determined after stimulation of the cells with the various bacteria. Of the bacterial species tested, B. fragilis proved to be one of the most potent triggers for prostaglandin E2 release from neutrophils indicating a possible major role of this microorganism in the pathogenesis of mixed infections.

Adult↗
PubMed1993

[Mefloquine and sulfadoxine/pyrimethamine overdose in malaria tropica].

A 39 year-old man with malaria due to Plasmodium falciparum received 3500 mg mefloquine over 3 days, in addition to 3250 mg chloroquine and 175/3500 mg sulfadoxine/pyrimethamine. He developed severe neuropsychiatric symptoms and had to be hospitalized. Treatment with diazepam, haloperidol and thioridazine achieved relief of the severe symptoms after 4 days. The patient was still suffering from discrete neuropsychiatric symptoms 8 months after treatment.

Adult↗
PubMed1992

Comparison of HTK- and UW-solution for liver preservation tested in an orthotopic liver transplantation model in the pig.

The aim of this experimental study was to compare the preservation potency of University of Wisconsin (UW) and HTK (Bretschneider) solutions in an orthotopic liver transplantation (OLT) model in pigs. Livers were harvested using an in situ perfusion technique, where organs were flushed with the solution being tested, stored on ice--cold storage (CS)--for 2 or 24 h and then transplanted. Parameters monitored were liver enzymes in serum, hepatic water content, high energy phosphates, nuclear magnetic resonance (NMR) relaxation time T2, light microscopy and bile production. CS for 24 h is an extreme in pig liver preservation and is not compatible with animal survival. Biopsies showed drastic morphological changes and grafts did not produce bile in either group. (Bile production 2 h CS: HTK, 5.6 +/- 1.8 ml/h; UW, 4.7 +/- 2.3 ml/h) Enzyme release after reperfusion (deltaSGOT, deltaLDH) was higher in long-term preservation. Hepatic tissue water content significantly decreased during CS in UW preserved livers. Edema alter reperfusion (deltaH2O: HTK 24 h = +5.6%, UW 24 h = +4.8%) and regeneration capacity after reperfusion (UW 2 h = 63%, HTK 2 h = 55%, UW 24 h = 30%, HTK 24 h = 30%) were not significantly different. However, we did not observe major differences in preservation potency between the solutions tested. Differences were correlated, rather, with length 9 time of CS, than with the solution used. Therefore, HTK solution seemed to be a low potassium containing alternative to UW solution.

Adenosine↗
PubMed1992

Hepatotoxicity testing of atracurium and laudanosine in the isolated, perfused rat liver.

The pharmacokinetics of atracurium, which is degraded by Hofmann decomposition and ester hydrolysis, is not altered by impaired liver function. Atracurium should, therefore, be ideal for patients with heptic failure, and is now widely used in clinical practice. However, some studies reported considerable hepatotoxicity after atracurium, especially from its breakdown products--for example, leakage of lactate dehydrogenase (LDH) from isolated rat hepatocytes. Therefore, we have studied, in an isolated perfused rat liver model, biochemical and morphological changes after administration of either atracurium or its main metabolite, laudanosine. Despite using extremely high concentrations of these substances, we could not detect, biochemically (release of LDH or aspartate amino-transferase (AST)) or histologically, any signs of liver cell damage.

Animals↗
PubMed1992

Cold-preserved rat liver viability testing by proton nuclear magnetic resonance relaxometry.

The results of a series of experiments in the cold-preserved rat liver, applying a newly developed method of pretransplant viability testing, are described. The livers were stored either under simple hypothermic conditions (KHB) or in EC, HTK, or UW preservation solution. Livers were stored up to 48 hr and reperfused after a period of hypothermic storage of 1, 7, 14, or 21 hr. In a parallel series of experiments, with livers stored under identical conditions, repeated proton relaxometry measurements (0, 1, 7, 14, 24, 32, 48 hr) were undertaken; and ATP, ADP, AMP (Atkinson's energy charge), and water content of livers, as well as pH of storage solution, were estimated. Based on a strong correlation between proton spin-spin relaxation time T2 and tissue water content (edema), this new method may be useful to estimate the amount of cell swelling during hypothermic storage from a surgical biopsy of about 200 mg within a few minutes. There was, however, no significant correlation found between energy charge and/or pH and water content, T2, or bile flow. Our method could be useful as a rapid test method in experimental cold liver storage models and may be of interest in human liver transplantation as a viability indicator in combination with other parameters.

Animals↗