Search PubMed⌕ Search

Biomedical subjects

M Herold

Publications and source records attributed to M Herold.

At least 145 records · Page 8Linked to original sources

Plasma lignocaine concentrations associated with extradural analgesia in patients with and without multiple organ failure.

We have measured plasma concentrations of lignocaine after thoracic extradural analgesia with continuous infusion of lignocaine in eight intensive care patients with chest wall trauma or after major upper abdominal surgery. Four patients developed multiple organ failure (MOF). Plasma concentrations of lignocaine in arterial blood were measured 4, 8, 24 and 48 h after a continuous infusion of lignocaine was commenced in the extradural space. Plasma concentrations of lignocaine were greater in all patients with MOF (range 2.7-5.1 micrograms ml-1) than in patients without MOF (range 0.8-1.2 micrograms ml-1). Because plasma concentrations in patients with MOF were within the low toxic range, extradural infusion of lignocaine should only be considered in intensive care patients without MOF or when plasma concentrations of lignocaine are monitored.

Adult↗

Interleukin-8 serum concentrations after liver transplantation.

The study's objective was to investigate serum levels of interleukin-8 (IL-8) after liver transplantation and to correlate these findings with tumor necrosis factor alpha serum levels and various clinical parameters. This was a prospective observation study conducted at the University Hospital of Innsbruck with 19 patients studied after orthotopic liver transplantation. Serum levels of IL-8 were analyzed by a solid-phase double ligand ELISA method. Serum TNF-alpha concentrations were measured by means of a commercially available radio immunoassay (IRE-Medgenix, Fleurus, Belgium). Three patients with an uneventful recovery after transplantation showed IL-8 levels below the detection limit. IL-8 serum levels markedly increased in patients with acute graft rejection, bacterial infection, and CMV disease. Increments of serum IL-8 preceded clinical complications in all patients. Highest levels were observed in bacterial infection, lowest in acute rejection. A statistically significant positive correlation was demonstrated between IL-8 and TNF-alpha serum levels in the context of bacterial infection and CMV disease. Elevated IL-8 serum levels represent a feature of alloimmune and infectious complications following liver transplantation. IL-8 can thus be considered a further indicator molecule in the heterogenous group of acute-phase reactants that accompany various inflammatory responses and do not permit the underlying clinical complication to be specified.

Adult↗

Circulating serum levels of interleukin 6 and C-reactive protein after liver transplantation.

The study objectives were to investigate serum levels of interleukin-6 and C-reactive protein (CRP) after liver transplantation to correlated measurements with various clinical parameters. Twenty-three patients were studied after orthotopic liver transplantation. Serum IL-6 activity was evaluated by testing its capacity to induce proliferation of the IL-6-dependent hybridoma cell line B9. CRP was assessed by a nephelometric method. Only two of seven patients with acute cellular rejection developed an increase of serum IL-6 and CRP. In contrast to this rejection group, elevated IL-6 levels were observed in 7/9 patients with bacterial infections. Peak values for IL-6 were observed one day and for CRP two days after clinical diagnosis of infection. CMV disease was also associated with markedly increased IL-6 and CRP levels in 5/7 patients. Surprisingly, levels in this condition were approximately in the same range as in bacterial infection. IL-6 and CRP serum levels seen in bacterial infection and CMV disease were significantly higher than those in rejection (P less than 0.001). Serum IL-6 activity was neutralized by an antiserum directed against recombinant human IL-6. Preferential elevations of IL-6 and CRP represent one feature of bacterial and viral infections. Elevation of TNF during rejection as described earlier is only rarely accompanied by increased serum IL-6 levels.

Bacterial Infections↗

Proinflammatory cytokines in cardiac myxomas.

Serum levels of various cytokines were measured in three patients with cardiac myxomas presenting with and without constitutional symptoms, immunological features and elevated plasma levels of interleukin-6. Interleukin-6 but not other cytokines (interleukin-1, tumour necrosis factor-alpha, interferon-gamma) relate to immunological features of the patients. Circulating levels of atrial natriuretic peptide correspond to haemodynamic changes but not to the tumour-bearing state itself.

Atrial Natriuretic Factor↗

Atrial natriuretic peptide (ANP), aldosterone, angiotensin II and renin in the 'low T3 syndrome' in organ donors.

The present prospective study was conducted in order to investigate the effect of an acute decrease in serum T3 levels on ANP, aldosterone, angiotensin II, renin and ADH. All patients showed a pathologic TRH stimulation test prior to organ harvesting. Our patients developed secondary T3 hypothyroidism of different severity dependent on intensive care unit (ICU) stay. T3 values in group 1 (ICU stay > or = 77 h) were smaller than 70 ng/dl, those of group 2 (ICU stay < or = 53 h) were greater than 70 ng/dl. In both groups a severe elevation of plasma renin activity was measured, with almost high-normal values for ANP in group 1 and slightly elevated values in group 2 [not significant (n.s.)]. Results demonstrate that, contrary to patients who are not critically ill, brain-dead patients develop a dissociation of the renin-angiotensin-aldosterone mechanism. No statistical significant difference was found between the groups in serum levels of ADH and aldosterone. This endocrine dissociation, however, seems to have no clinical significance with regard to organ function after transplantation in kidney recipients.

Aldosterone↗

Predictive value of interleukin-6 and neopterin in patients with multiple myeloma.

Concentrations of interleukin-6 and neopterin were measured in sera from 44 patients with multiple myeloma. To judge the relative prognostic value of these analyses, other clinical and laboratory variables were concomitantly determined. The patients were followed up to 9 years, and the abilities of all variables to predict outcome were assessed. Both neopterin (P = 0.0008) and interleukin-6 (P = 0.033) were significantly higher in patients with higher stages of the disease. The correlation between interleukin-6 and neopterin was weak but significant (Spearman's rank correlation coefficient, 0.38; P = 0.019). By univariate survival analysis using the product-limit approach, both neopterin (P = 0.0001) and interleukin-6 (P = 0.025) were identified as significant predictors of survival. Multivariate survival analyses by the proportional hazards technique demonstrated that either stage and neopterin or neopterin and interleukin-6 are useful combinations of predictor variables. Thus, interleukin-6, which is supposed to influence progression of multiple myeloma in an autocrine or paracrine manner, failed to contribute to prediction if stage was included in a model. In contrast, neopterin remained significant in all multivariate models.

Aged↗

Autonomous folding and coenzyme binding of the excised pyridoxal 5'-phosphate binding domain of aspartate aminotransferase from Escherichia coli.

The coenzyme (PLP) binding domain (residues 47-329) of the dimeric aspartate aminotransferase from Escherichia coli was produced separately by recombinant DNA methods. It folded autonomously both in vivo and in vitro, that is, independently of the native N- and C-terminal extensions that combine to form the small domain of eAAT. The PLP-domain had one binding site for PLP of relatively high affinity involving a covalent bond to the protein. It was monomeric, although the major subunit-subunit interface at the 2-fold symmetry axis remained unchanged. This effect appears to be due mainly to the absence of the N-terminal extension that contains hydrophobic residues, which interact with the PLP-domain of the second subunit in the wild-type dimer. Judged by circular dichroism, fluorescence, and HPLC gel filtration at increasing concentrations of guanidinium chloride, the PLP-domain underwent a three-state unfolding transition (M' in equilibrium M'* in equilibrium U') involving a compact intermediate M'*. This behavior parallels the unfolding of the dissociated native monomer of cAAT.

Apoenzymes↗

Unfolding of truncated and wild type aspartate aminotransferase studied by size-exclusion chromatography.

The reversible unfolding of globular proteins with increasing concentration of guanidinium chloride (GuCl) can be analysed by size-exclusion chromatography, because the hydrodynamic volume of the proteins increases during unfolding. The dimeric enzyme aspartate aminotransferase (AAT) shows an uncoupled dissociation of the identical subunits followed by the unfolding of the monomers. During the monomer unfolding formation of an intermediate is observed. A monomeric mutant of AAT unfolds with a similar shape of the unfolding transition phase, but is less stable, as shown by a shift of the transition mid-point from 1.7 M GuCl for the wild type to 1.3 M GuCl for the mutant.

Aspartate Aminotransferases↗

Suppression of thyroid function by interferon-alpha 2 in man.

Profound biological changes occur in patients treated with interferon. Observations of endocrine changes prompted us to examine the effects of subcutaneous alpha-interferon administration in single doses on circulating levels of thyroid stimulating hormone, total thyroxine, and total triiodothyronine in 10 volunteers (5 healthy subjects and 5 patients with hepatitis C). Blood samples were taken on an out-patient basis immediately before and 2, 12, 24, 48, and 72 h after administration of 1, 3, or 5 x 10(6) units of recombinant alpha-interferon. Application of the different dose levels was randomly assigned. Plasma samples were stored at -80 degrees C; after collection of samples had been completed hormone levels were measured using commercially available test kits. At all time points before and after injection of alpha-interferon, standard deviations of measured hormone levels of healthy control subjects and patients overlapped to a considerable extent. At a dose level of 5 x 10(6) units, alpha-interferon significantly increased cortisol levels as described, and decreased the level of thyroid stimulating hormone in the group receiving alpha-interferon as compared to placebo-treated healthy volunteers. The effects occurred 12 h after injection. Maximum suppression of thyroid stimulating hormone levels was observed 24 h after injection, when serum levels of thyroxine and triiodothyronine also were significantly reduced. We conclude that subcutaneous alpha-interferon treatment with doses as low as 5 x 10(6) units affects the control of thyroid function.

Adult↗

Acute hematologic effects of interferon alpha, interferon gamma, tumor necrosis factor alpha and interleukin 2.

This study was designed to investigate acute effects of various doses of the cytokines IFN-alpha, IFN-gamma, Interleukin 2 and tumor necrosis factor alpha on white blood cell differential counts. Before initiation of phase II trials, a dose-determination phase was performed, where three different dose levels of each cytokine were applied as a single dose. White blood cell differential counts were assessed immediately before and 2, 12, 24, 48 and 168 h after injection. Patients enrolled suffered from metastatic cancer or chronic active hepatitis. In addition, IFN-alpha was administered to five healthy volunteers. Results indicate that cytokines cause rapid and transient changes in the numbers of leukocyte subsets. Hematologic changes were cell-type- and cytokine-specific: transient lymphopenia was observed after administration of all four cytokines, reaching a nadir 12 to 24 h after subcutaneous injection. Administration of TNF-alpha and IFN-gamma also caused transient monocytopenia. Neutrophilia developed after administration of Interleukin 2, IFN-alpha and TNF-alpha. We conclude that cytokines play a key role in the regulation of peripheral blood cell traffic by their capacity to influence homing patterns of peripheral blood leukocytes.

Female↗

Immunotherapy with monoclonal anti-idiotypic antibodies: tumour reduction and lymphokine production.

A patient with a B-cell chronic lymphocytic leukaemia was treated with a murine IgG1 monoclonal anti-idiotypic antibody (MoAb anti-id). After a total of 773.2 mg MoAb anti-id had been administered with a maximum daily dose of 83.2 mg, 90% tumour reduction was established within 2 weeks. Although in vitro the tumour cells were stimulated by MoAb anti-id no signs of tumour cell activation were observed in vivo during therapy with MoAb anti-id. The rapid tumour reduction suggests that the proliferation-enhancing property of anti-id is not a contra-indication for immunotherapy. The FcR II receptors on the patients monocytes could interact with the IgG1 monoclonal used. MoAb anti-id administration induced strongly decreased platelet counts, dependent on the amount of serum idiotype that had to be cleared. Antibody administration activated the macrophage/monocyte system, reflected in the neopterin profile, resulting in TNF alpha production and simultaneously strong reductions of circulating tumour cells. The partial remission lasted 3 months, then the tumour reappeared. These data show that a straightforward therapy with MoAb anti-id, in itself, has a strong potential, but is not sufficient to eradicate the tumour permanently. Further study will be needed to improve the clinical results with this kind of therapy.

Aged↗