Gastrointestinal transit and digestibility of maltitol, sucrose and sorbitol in rats: a multicompartmental model and recovery study

Using data obtained with a dye marker and the gavage technique, the kinetics of gastrointestinal transit of different loads of sugar substitutes (maltitol, sorbitol) and sugar (sucrose) in the rat were analysed using a linear multicompartmental model over a range from the realistic to the non-physiologic high, of carbohydrate intake levels and using only a few experimental time points. The model gave detailed insight into intestinal propulsion and gastrocecal transit time. Rate constants of transport between the compartments investigated were determined; they showed characteristics which could be related to the substance and the dosage administered. Analyses of the gastrointestinal content and calculations of the intestinal net water movement showed that the digestibility and absorption of the disaccharide sugar alcohol, maltitol, in the small gut depended inversely on the dose ingested. For all substances tested, caloric availability in the small intestine was calculated. At a physiological low level of maltitol intake, the results also indicated an insignificant calorie-saving effect in comparison to sucrose, an effect based mainly on the slow absorption rate of the maltitol cleavage product sorbitol.

Coenzyme binding of a folding intermediate of aspartate aminotransferase detected by HPLC fluorescence measurements

Equilibrium dissociation and unfolding of dimeric aspartate aminotransferase from Escherichia coli proceeds via two compact monomeric intermediates which have similar hydrodynamic volumes but different fluorescence properties. We probed binding of the coenzyme pyridoxal 5'-phosphate to these intermediates by coupling fluorescence detection to size-exclusion HPLC. This procedure gave additionally an internal conformational probe of the unfolding transitions of the enzyme. It was shown that the first intermediate, M, is able to bind the coenzyme, whereas the second intermediate, M*, is not. It is likely that M is the correctly folded monomer of the protein.

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.

Neuropharmacological study of aged MAM-treated rats

After evaluation of activity in an open field, norepinephrine (NE), serotonin (5HT), 5-hydroxyindolacetic acid (5HIAA), homovanillic acid (HVA), and choline acetyltransferase (CAT) were investigated in cortex of 26-month-old rats poisoned with methylazoxymethanol (MAM) as compared to control rats of the same age. NE and 5HT concentrations showed a marked increase, but levels were normal when expressed as total content, just as in MAM-exposed young adults. Concentrations of 5HIAA were also increased but to a lesser extent than 5 HT. Aged MAM rats did not show any modification of spontaneous activity although hyperactivity is characteristic of young adults exposed to MAM. Together with this behavioral observation, a significant decrease in total HVA content was measured. Because HVA levels seem correlated with activity in MAM-exposed rats, we speculate that the behavioral abnormality recovers in old age. Total CAT activity was also reduced. These results indicate that the neurochemical pattern of young adult MAM-poisoned rats is conserved in aged rats except for some changes in the dopaminergic and cholinergic systems.

Serum levels of cytokines in chronic liver diseases

Serum levels of interleukin-1 (IL-1 beta), interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-alpha), interferon gamma (IFN-gamma), and C-reactive protein (CRP) were investigated in patients with chronic liver diseases (CLD) and correlated with the type of underlying disease and various clinical and laboratory parameters. Two hundred sixty-four patients suffering from various CLD were studied; 136 cases presented with liver cirrhosis, and 128 patients were in the noncirrhotic stage of their underlying liver diseases. Serum levels of IL-1 beta, IL-6, TNF-alpha, IFN-gamma, and CRP were elevated in patients with CLD. Endogenous cytokine patterns in CLD were stage dependent and only marginally affected by the type of underlying disease. The cirrhotic group of CLD patients showed higher serum levels in IL-1 beta, IL-6, TNF-alpha, and CRP than did noncirrhotic cases, and these differences reached the level of statistical significance. IL-1 beta and TNF-alpha values were closely correlated but did not correlate with IL-6 levels. Elevated concentrations of cytokines represent a characteristic feature of CLD regardless of underlying disease. This and the apparent stage-dependency suggest that enhanced endogenous cytokine levels represent a consequence of liver dysfunction rather than of inflammatory disease.

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.

Increased serum interleukin 6 levels in patients with myelodysplastic syndromes

Serum concentration of interleukin 6 (IL-6) was measured in 45 patients with myelodysplastic syndromes (MDS). A commercially available enzyme-linked immunosorbent assay (ELISA) with a sensitivity of 3 pg/ml was used. While IL-6 was undetectable in healthy volunteers, 32 of the patients with MDS showed IL-6 concentrations higher than 3 pg/ml. In MDS we found serum concentrations of IL-6 between 0 and 150 pg/ml with a median of 9 pg/ml, mean and standard deviation (SD) were 15 and 26 pg/ml respectively. In refractory anemia with excess of blasts in transformation (RAEB-t) the serum IL-6 concentrations were significantly higher than in refractory anemia (RA; p = 0.0025), in refractory anemia with excess of blasts (RAEB; p = 0.0050) and in chronic myelomonocytic leukemia (CMML; 0.0449). No significant difference was detected between RA and RAEB or between CMML and the other types of MDS, while s significant negative correlation was found between the concentrations of IL-6 and hemoglobin (p = 0.0228).

Collapsed intermediates in the reconstitution of dimeric aspartate aminotransferase from Escherichia coli

Aspartate aminotransferase from Escherichia coli, which had been denatured by guanidinium chloride, refolded and reassembled to active dimers in two distinct phases. The unfolded monomer U collapsed within 20 s to an intermediate I* that was inactive, fluoresced more strongly than, but had the same peptide CD signal as the native dimer. The formation of crosslinkable dimers, as well as the recovery of enzyme activity, occurred with a biphasic progress curve which was independent of protein concentration. The half-lives of the two phases were 100 s and 2000 s. The data are consistent with a three-step mechanism, in which the overall rate of reassembly is determined by an isomerization of I* to the assembly-competent monomer M. The latter does not accumulate because it dimerizes rapidly to the active enzyme (D). Reassembly of the enzyme from the compact intermediate M*, which is stable at 1.0 M guanidinium chloride, also proceeded in a rapid and a slow phase. Moreover, the formation of M* from the unfolded state was rapid, whereas its refolding to the native dimer was slow. Both the transient intermediate I* and the equilibrium intermediate M* qualify as 'collapsed intermediate' or 'molten globule' states.

A short multilingual quality of life questionnaire--practicability, reliability and interlingual homogeneity

International cooperative clinical trials require a multilingual quality of life questionnaire. The 'International Society for Chemo- and Immunotherapy' therefore designed a study to develop and test a 'health accentuated' quality of life questionnaire in the eight languages spoken in this society. The objective was to examine practicability, reliability and interlingual homogeneity. Versions of the questionnaire in Czech, German, Hungarian, Italian, Kroatian, Polish, Romanian and Slovakian have been prepared. The results are based on data of 1,104 adult patients. They demonstrate that the developed questionnaire is practicable. Patients need 10-15 min to answer it, usually without assistance. The proportion of missing values is for all but two questions less than 3%. The questionnaire also found high acceptance reflected by only 2.7% refusals. It is reasonably reliable in each language. Interlingual homogeneity could be shown by demonstration of strong structural similarities between the different versions using multidimensional scaling, factor analysis and comparison of mean profiles.

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.

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.

Detection of soluble IL-2 receptor in the serum of patients with myelodysplastic syndromes: induction under therapy with GM-CSF

Sera of 15 healthy controls and 33 patients suffering from myelodysplastic syndromes (MDS) were investigated for soluble interleukin-2 receptor (sIL-2R) expression with a cell-free enzyme-linked immunosorbent assay (ELISA) system (T-Cell Sciences; Cambridge, U.S.A.). The upper limit of the assay is indicated with 477 U/ml. According to the FAB classification eight refractory anaemia (RA), 15 refractory anaemia with excess of blasts (RAEB), five refractory anaemia with excess blasts in transformation (RAEBt) and five chronic myelomonocytic leukaemia (CMML) were examined. None of the patients had reported infectious episodes or been under treatment with cytotoxic agents and/or cytokines within the previous 3 months. Significant differences in sIL-2R levels between RA (median 368 U/ml). RAEB (median 675 U/ml) and RAEBt (median 971 U/ml) and between RA and CMML (median 723 U/ml) were detected. Six patients, who had been under treatment with rhGM-CSF for at least 2 weeks, demonstrated a three- to sevenfold increase of sIL-2R expression compared to pretreatment levels. In kinetic evaluation of serum samples for 24 h, the increase of sIL-2R expression begins within 4 h after subcutaneous application of GM-CSF and reaches its maximum after 12 h. Our data cannot suggest whether increased sIL-2R expression is a primary event due to involvement of lymphocytes in the malignant clone or whether it results from secondary alteration of the cytokine network. Application of GM-CSF in MDS may result in improvement of altered lymphocyte function. As GM-CSF induces sIL-2R expression, a down regulation of the immune response caused by neutralization of free IL-2 cannot be excluded.

Enhanced serum levels of soluble HLA class I molecules are induced by treatment with recombinant interferon-gamma (IFN-gamma)

In order to investigate serum levels of soluble HLA class I antigens after single injection of various doses of recombinant IFN-gamma (rIFN-gamma) and to correlate the changes observed to beta-2-microglobulin serum levels, we studied five patients with metastasizing renal cell carcinoma. Each patient received three treatment cycles of 10, 100 and 500 micrograms rIFN-gamma three times at weekly intervals. The treatment cycles were separated by a therapy-free interval of 2 weeks. The order of dose levels was randomly assigned to each patient. Serum levels of soluble HLA class I proteins were measured by an ELISA in samples drawn immediately before and 4, 24, 48, 72 and 168 h after each administration of rIFN-gamma. Beta-2-microglobulin was assessed in parallel using a commercially available radioimmunoassay. Significant induction of soluble HLA class I protein serum levels was observed after treatment with 100 and 500 micrograms rIFN-gamma. The increments peaked after 2-4 days and remained elevated for up to more than 7 days. A significant correlation between increments of soluble HLA class I proteins and beta-2-microglobulin was observed. We conclude that measurement of soluble HLA serum levels is practical for monitoring induction of HLA class I synthesis in patients treated with rIFN-gamma. The correlation observed between induction of beta-2-microglobulin and soluble HLA class I proteins indicates that measurement of beta-2-microglobulin might be sufficient for the biological response monitoring in clinical studies.

[Determination of anti-arrhythmia therapy of ventricular arrhythmias based on programmed ventricular stimulation]

The authors used programmed ventricular stimulation in 38 patients who had during Holter monitoring severe ventricular arrhythmias (greater than or equal to Lown 4a). The group comprised patients with IHD (22x), hypertrophic (11x) and dilatating cardiomyopathy (2x). Three patients had no organic heart disease. Nine patients were treated at the time of examination with antiarrhythmic drugs. In a total of 16 patients it proved possible to provoke ventricular tachycardia (VT)--four times permanent ventricular tachycardia, 12x transient ventricular tachycardia (NSVT). In the group of treated patients SVT was provoked twice and NSVT also twice, always in patients who took amiodarone. Using programmed ventricular stimulation the following antiarrhythmic drugs were tested: mexiletine, cordarone, ajmaline. The capacity of all tested antiarrhythmics in the prevention of VT was comparable. A total of two patients died during the investigation, in both cases a sudden death. One suffered from hypertrophic cardiomyopathy, one from IHD. In both on Holter monitoring NSVT episodes were revealed. Programmed stimulation provoked in both SVT, both were treated at the time of death with tested antiarrhythmics. The authors conclude that programmed ventricular stimulation is a suitable method for rationalization of antiarrhythmic treatment, the clinical results, however, do not correspond to laboratory results. They recommend therefore to use also Holter monitoring of patients at risk.

Cachexia and tumour necrosis factor-alpha in cytomegalovirus infection

Although cachexia is a common feature of cytomegalovirus infection, little is known about its cause. To explore any contributory role that tumour necrosis factor-alpha (TNF) might have the serum concentrations of TNF in eight patients who developed CMV disease after liver transplantation were investigated. All patients exhibited pronounced and long lasting increases in TNF serum concentrations. Increased endogenous TNF concentrations were associated with weight loss and anorexia. In contrast, liver transplant recipients without CMV disease showed no weight loss.

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.

Recovery of biologically active enzymes after HPLC separation

The mass and activity recovery of eight different enzymes (two monomeric, six oligomeric) with molecular masses between 25,000 and 240,000 daltons were tested after HPLC separation on three different HPLC instruments (two with stainless steel and one with titanium flow paths). Most of the tested proteins are known to be sensitive to heavy metal ions. Eight wide pore, ion-exchange columns, two size-exclusion columns and two hydrophobic-interaction columns were used. Both stainless steel and glass column hardware were used in all three separation modes. The elution times were between 8 and 12 minutes. In almost all cases, the activity recovery was between 90% and 100% compared with a control sample incubated in the chromatographic elution buffer for the same time at the same temperature. A severe activity loss (about 30%) was observed with only one ion-exchange column and one enzyme. Neither the column hardware nor the material of the HPLC equipment had any negative effect on the activity recovery of the enzymes tested.

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.

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.

Serum levels of interleukin-6 in multiple myeloma and other hematological disorders: correlation with disease activity and other prognostic parameters

Interleukin-6 (IL-6) is a multifunctional cytokine involved in the regulation of the terminal differentiation pathway of B lymphocytes. Recent reports revealed its potential role in the in vitro and in vivo growth of human multiple myeloma cells. The mechanism, however, by which IL-6 triggers proliferation of malignant plasma cells remains controversial. Using the very sensitive 7TD 1 bioassay we quantified endogenous circulating IL-6 levels in serum samples of 104 patients suffering from monoclonal gammopathies and other hematological disorders [47 with multiple myeloma (MM), 24 with monoclonal gammopathy of unknown significance (MGUS), 8 with myeloproliferative disease, and 25 suffering from low-grade non-Hodgkin's lymphoma (NHL)]. Elevated serum levels of IL-6 (greater than 5 pg/ml) were detected in 42% of the patients with MM, in 13% with MGUS, in 15% with low-grade B-NHL, and in 1 patient with T-NHL. In patients suffering from chronic myeloproliferative diseases, IL-6 levels were within the normal range. In patients with myeloma, IL-6 levels were significantly higher at advanced stages (II/III) or with progressive disease than in patients with MM stage I, MGUS, or at the plateau phase (P less than 0.01). In patients with monoclonal gammopathies including MGUS, serum IL-6 levels correlated with neopterin, tumor necrosis factor alpha and beta 2-microglobulin. An inverse correlation was found with hemoglobin levels. From these results, we propose that in myeloma patients serum IL-6 levels may reflect disease activity and tumor cell mass. The correlation with serum neopterin, a macrophage product, also suggests its origin in an activated immune system.

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.

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.

Recombinant tumour necrosis factor alpha administered subcutaneously or intramuscularly for treatment of advanced malignant disease: a phase I trial

The pharmacokinetics, toxicity and biological effects of subcutaneous and intramuscular treatment of cancer patients with recombinant tumour necrosis factor alpha (rTNF-alpha) was investigated. 17 patients suffering from refractory malignant disease were treated with either 1.0 micrograms/m2, 10 micrograms/m2 or 100 micrograms/m2 rTNF-alpha. Vital signs, peripheral blood cell counts, TNF and interferon (IFN) gamma serum levels, neopterin, beta 2-microglobulin, C reactive protein (CRP) and cortisol levels were measured immediately before and 2, 12, 24, 48 and 168 h after the first administration of rTNF-alpha. Tumour response was evaluated after 4 and 12 weeks of treatment. The pharmacokinetics followed the same characteristics as those reported for other cytokines. Major toxicities were dose dependent and comprised fever, constitutional symptoms and hypotension. TNF dependent changes were observed in serum levels of IFN-alpha, CRP, neopterin, beta 2-microglobulin, cortisol and white blood cell counts. No objective tumour response was observed. This study indicated that rTNF-alpha administered subcutaneously or intramuscularly results in measurable TNF serum levels, significant toxicity and biological response in absence of clinical efficacy in patients with advanced cancer.

Differences in non-MHC restricted cytotoxic activities of human peripheral blood lymphocytes after transfusion with allogeneic leukocytes or platelets possessing class I and/or class II MHC molecules

MHC-unrestricted cytotoxic activity of peripheral blood lymphocytes (PBL) from 4-6 healthy donors was investigated before and after transfusion with allogeneic leukocytes or platelets. Natural killer and lectin-dependent cellular cytotoxicity (LDCC) of PBL was tested against K562 and Raji target cells in a 4-h and 16-h 51Cr-release assay, respectively. After allotransfusion with leukocytes, we found increased cytotoxic activity of each donor's PBL against all the three targets on day 3 or 7. The highest non-specific cytotoxic activity was detected against the relatively NK resistant Raji target cells. The increase of cytotoxic activity was lowest against the LDCC target (PHA-treated Raji) cells. On the contrary, no changes in cytotoxic activity against any targets were observed after allotransfusion with platelets (possessing class I HLA antigens but no HLA class II molecules). Our results suggest that HLA class II molecules, presumably by inducing immune responses, are essential for activation/generation of non-specific killing of tumor targets after leukocyte transfusion. Thrombocytes, known to be less immunogenic than leukocytes, are not effective in in vivo enhancing of non-specific cytotoxicity. Cellular activation of PBL following leukocyte allotransfusion was confirmed by detection of elevated serum neopterin and beta-2-microglobulin levels on day 3. This was not the case after platelet allotransfusion. In addition, the expression of ICAM-1 antigen (as a molecule involved directly in MHC-unrestricted cytotoxicity) was also found to be increased in two donors' PBL on day 3 after leukocyte transfusion in contrast to transfusion with platelets.

A monoclonal antibody directed against the human intercellular adhesion molecule (ICAM-1) modulates the release of tumor necrosis factor-alpha, interferon-gamma and interleukin 1

ICAM-1 is a cell surface glycoprotein which is one of the ligands for the leukocyte function-associated antigen (LFA-1). It is involved in leukocyte adhesion to endothelial cells as well as in immune functions requiring cell-cell contact. The quantitative expression of ICAM-1 in various cell types can be either induced or enhanced by treatment with cytokines, such as interferon-gamma (IFN-gamma), tumor necrosis factor (TNF)-alpha or interleukin 1 (IL 1), a phenomenon which results in the augmentation of binding to LFA-1-positive cells. In contrast, treatment with anti-ICAM-1 antibodies blocks this binding. A monoclonal antibody (mAb), termed 7F7, which recognizes an epitope on ICAM-1, was used to investigate the role of ICAM-1 in cytokine production by T lymphocytes and monocytes. Production of TNF-alpha. IFN-gamma and IL1 was significantly inhibited (p less than 0.01) by the incubation of mAb 7F7 with phytohemagglutinin-activated blood mononuclear cells (MNC) or isolated E rosette-positive T lymphocytes. The maximal level of inhibition was reached with 1 microgram/ml of purified antibody. A similar inhibition was obtained using saturating concentrations of 400 microliters/ml of mAb 7F7 hybridoma supernatant corresponding to an inhibitory activity of 1 microgram of purified mAb. In contrast, granulocyte/macrophage-colony-stimulating factor release showed a heterogeneous response over five experiments with an increase found in three experiments and a decrease in two experiments. Addition of increasing concentrations of supernatant or purified mAb to unstimulated MNC or T lymphocyte cultures had no effect on cytokine release. The observed inhibition of the production of TNF-alpha. IFN-gamma and IL 1 by antibody-mediated blockade of the ICAM-1 structure probably represents a negative circuit that serves to tune the activation of leukocytes and to avoid an overproduction of cytokines.

Endogenous IFN-gamma during human bone marrow transplantation. Analysis of serum levels of interferon and interferon-dependent secondary messages

Serum levels of interferon-gamma and the IFN-dependent marker molecules neopterin and beta 2-microglobulin were assessed in BMT recipients. Concentrations of the latter two markers were corrected for creatinine levels in order to eliminate the impact of alteration of kidney function. Serum levels were assessed daily using commercially available radioimmunoassays. Twelve patients were studied during the early phase of allogeneic bone marrow transplantation and eleven additional patients during complications of BMT. Results indicated that both the conditioning regimen for BMT as well as major clinical complications such as infection and acute graft-versus-host disease strongly influence the endogenous patterns of the lymphokine and its secondary messages. During allogeneic BMT IFN-gamma and neopterin levels exhibited a biphasic pattern with a first peak during conditioning with high-dose cyclophosphamide and a second still higher peak at the time of hemopoietic regeneration. beta-2-microglobulin ratios increased during conditioning and remained elevated throughout observation. Serious infections of bacterial and viral origin as well as GvHD were accompanied by elevated levels of all three serum parameters studied. The kinetics of enhanced endogenous production, however, differed between infectious complications and GvHD. Increasing concentrations were observed during infections subsequent to clinical manifestation, whereas they preceded disease manifestation in GvHD.

Treatment of cancer patients with recombinant interferon-gamma induces release of endogenous tumor necrosis factor-alpha

STUDY OBJECTIVE

1) to investigate serum levels of tumor necrosis factor-alpha in patients treated with recombinant interferon-gamma and 2) to relate changes in TNF serum levels to other biological responses observed during treatment with interferon gamma (IFN-gamma).

PATIENTS

Five patients suffering from metastasizing renal cell carcinoma.

INTERVENTION

Each patient received three treatment cycles of 10 micrograms, 100 micrograms and 500 micrograms IFN-gamma applied three times at weekly intervals. The treatment cycles were separated by a therapy free interval of two weeks. The order of dose levels was randomly assigned to each patient.

MEASUREMENTS AND MAIN RESULTS

Tumor necrosis factor alpha (TNF-alpha), IFN-gamma and neopterin serum levels, monocyte counts in the peripheral blood and body temperature were measured immediately before and 4, 24, 48, 72, and 168 h after each application of IFN-gamma. Results indicated that elevated serum levels of TNF-alpha are induced by 100 micrograms and 500 micrograms IFN-gamma. Repeated application of the same dose led to downregulation of TNF release into the serum. Changes in TNF serum levels did not correlate with the magnitude of febrile reactions, neopterin production or IFN-gamma serum levels.

Evaluation of cytokines and cytokine-induced secondary messages in sera of patients after liver transplantation

The study objective was first to investigate serum levels of tumor necrosis factor alpha, interleukin 1 beta, interferon gamma, interferon alpha, interleukin 2, beta-2-microglobulin (B2M), and urinary neopterin in patients after orthotopic liver transplantation; and second to relate their levels to clinical complications. The design used was the prospective observation study, and the setting used was the transplant unit of a university medical center. Serum samples were collected from 20 patients every alternate day from transplantation until discharge. The measurements and main results were as follows: concentrations of cytokines, B2M, and neopterin were performed using commercially available radioimmuno-assays. In seven out of nine patients with acute cellular rejections, elevated levels of TNF-alpha, IFN-gamma, IL-1, B2M, and neopterin were detected. The highest absolute levels of TNF-alpha were observed in patients with CMV disease. Increments in bacterial infections were comparable to those seen in the above-mentioned groups with the exception of IFN-gamma, which remained stable. IL-1 serum levels showed a different pattern with peak concentrations measured in sera before transplant and during rejection, while in the case of CMV disease levels gradually decreased. No detectable levels of IFN-alpha or IL-2 were observed. Our results indicate that enhanced endogenous production of TNF-alpha and IFN-gamma accompanied by elevated levels of B2M and neopterin represent a regular feature of inflammatory complications after liver transplantation. Serum cytokine levels however were not useful in distinguishing between rejection and infection. Evaluation of neopterin was more sensitive than cytokine or B2M measurement for the detection of inflammatory complications.

Reversible dissociation and unfolding of aspartate aminotransferase from Escherichia coli: characterization of a monomeric intermediate

The unfolding and dissociation of the dimeric enzyme aspartate aminotransferase (D) from Escherichia coli by guanidine hydrochloride have been investigated at equilibrium. The overall process was reversible, as judged from almost complete recovery of enzymic activity after dialysis of 0.7 mg of denatured protein/mL against buffer. Unfolding and dissociation were monitored by circular dichroism and fluorescence spectroscopy and occurred in three separate phases: D in equilibrium 2M in equilibrium 2M* in equilibrium 2U. The first transition at about 0.5 M guanidine hydrochloride coincided with loss of enzyme activity. It was displaced toward higher denaturant concentrations by the presence of either pyridoxal 5'-phosphate or pyridoxamine 5'-phosphate and toward lower denaturant concentrations by decreasing the protein concentration. Therefore, bound coenzyme stabilizes the dimeric state, and the monomer (M) is inactive because the shared active sites are destroyed by dissociation of the dimer. M was converted to M* and then to the fully unfolded monomer (U) in two subsequent transitions. M* was stable between 0.9 and 1.1 M guanidine hydrochloride and had the hydrodynamic radius, circular dichroism, and fluorescence of a monomeric, compact "molten globule" state.

[Modulation of hCG synthesis by alpha tumor necrosis factor in JAR choriocarcinoma cells]

The tumour necrosis factor (TNF) stimulates in cultured JAR choriocarcinoma cells the biosynthesis of hCG, including the free alpha and beta chain and the holo-hCG. Although elevated serum TNF levels have been shown by Balkwill et al. (1987) in about 50% of tumour patients, we were unable to confirm these data in the 10 examined patients, who had a choriocarcinoma. Despite its excellent in-vitro action, INF could not be confirmed to exercise an influence on the regulation of hCG in choriocarcinoma patients.

Consequences of 6 weeks of strength training on red cell O2 transport and iron status

Effects of endurance training on O2 transport and on iron status are well documented in the literature. Only a few data are available concerning the consequences of strenuous anaerobic muscular exercise on red cell function. This study was performed to test the influence of strength training alone on parameters of red cell O2 transport and iron status. Twelve healthy untrained males participated in a strength-training programme of 2-h sessions four times a week lasting 6 weeks. After 6 weeks a small but significant reduction of haemoglobin (Hb; -5.4 g.l-1) was found (p less than 0.05). Mean red cell volume did not change, but a pronounced decrease of mean cell Hb concentration (from 329.2 g.l-1, SE 2.5 to 309.8 g.l-1, SE 1.2; p less than 0.001) and mean corpuscular Hb (from 29.6 pg, SE 0.4 to 27.7 pg, SE 0.3; p less than 0.01) was observed. Serum ferritin decreased significantly by 35% (p less than 0.01); transferrin, serum iron and iron saturation of transferrin were unaltered. Serum haptoglobin concentration was diminished significantly by 30.5% (p less than 0.01). The reticulocyte count had already increased after 3 weeks of training (p less than 0.05) and remained elevated during the following weeks. Strength training had no significant influence on the O2 partial pressure at which Hb under standard conditions was 50% saturated, red cell 2,3-diphosphoglycerate and ATP concentration as well as on erythrocytic glutamate-oxalacetate transaminase activity. The data demonstrate that mechanical stress of red cells due to the activation of large muscle masses led to increased intravascular haemolysis, accompanied by a slightly elevated erythropoiesis, which had no detectable influence on Hb-O2 affinity. Training caused an initial depletion of body iron stores (prelatent iron deficiency). Although Hb had decreased by the end of the training phase a true "sports anaemia" could not be detected.

Successful treatment of metastatic renal cell carcinoma with a biologically active dose of recombinant interferon-gamma

We tested the clinical efficacy of a biologically active dose (BAD) of interferon (IFN)-gamma for treatment of progressive renal cell carcinoma (RCC). Twenty-two RCC patients with disease progression subsequent to nephrectomy were entered on a phase II clinical trial. During an initial dose-finding phase, biochemical responses to repeated once-weekly subcutaneous injections of 10, 100, or 500 micrograms of recombinant IFN-gamma were tested in 16 patients. Results indicated that 100 micrograms IFN-gamma applied once weekly was biologically active with induction of serum beta 2-microglobulin and neopterin. Such a dose induced a nearly maximum response of both markers lasting more than 4 days. This dose was also associated with minimal side effects. A dose of 100 micrograms IFN-gamma given once weekly was, therefore, subsequently given weekly for long-term treatment. During a median time of therapy of 10 months (range, 2 to 32 months) two complete (CR; 20+, 20+ months) and four partial tumor responses (PR; 6+, 7+, 8+, 24+ months) were seen (30% CR plus PR; 95% confidence limits, 12% to 54%) among 20 patients evaluable for response. Patients with refractory disease had significantly lower IFN-gamma-induced increments of serum beta 2-microglobulin than those who achieved clinical remission or stable disease.

[The intraperitoneal installation of gamma interferon for the treatment of refractory ovarian carcinoma]

Patients with refractory ovarian cancer were treated intra-peritoneally with interferon-gamma. The maximum tolerated dose was achieved at 2 mg/m2. The substance was administered 3 times per week every second week. Interferon-gamma treatment activated locally the macrophages and induced a rise in neopterin urine, serum, and ascites levels. The tumor marker CA-125 showed marked fluctuations of more than 100% during interferon treatment and this was not correlated with neopterin. A flu-like syndrome and especially fatigue were the dose limiting side effects. Two of 3 evaluable patients died on tumor progression whereas one is now 18 months clinically free of disease.

Acute effects of single doses of recombinant interferon-gamma on blood cell counts and lymphocyte subsets in patients with advanced renal cell cancer

The object of this study was to investigate the effects of different single doses of recombinant interferon-gamma (rIFN-gamma) on white blood cell counts, differential blood counts, and the relative composition of T-cell subsets in the peripheral blood of cancer patients. Sixteen patients suffering from metastasizing renal cell carcinoma received 10, 100, or 500 micrograms of rIFN-gamma three times at weekly intervals. After a therapy-free interval of 2 weeks, the next dose level was applied. The order of dose levels was assigned randomly to each patient. White blood cells, differential blood counts, and the number of Leu1, Leu3, Leu2a, Leu7, and HLA DR+ cells were measured immediately before and at 4, 24, 48, 72, 96, and 168 h after the administration of single doses of rIFN-gamma. Results indicated that white blood cells were transiently removed from the blood circulation after administration of IFN-gamma. Monocytes, HLA DR+ cells, and Leu7+ cells were reduced to below 50% of pretreatment values 4 h after application of the cytokine. CD8+ cells and granulocyte counts declined to approximately 70% of pretreatment values 24 h after IFN therapy. The preferential reduction of CD8+ lymphocytes resulted in a temporary increase of the T4/T8 ratio in these patients.

Occupancy of the iron-binding sites of human transferrin in sera obtained from different anatomical sites

Transferrin is the major iron-transport protein in serum. Four molecular species (apo-, two mono-, and diferric transferrins) can be distinguished on the basis of their occupancy with iron. These species differ physicochemically and in the affinity with which they bind to the transferrin receptor. To elucidate the possible role of the four molecular species in directing the flow of iron between the major anatomical sites of iron release and utilization we have analyzed sera from eight stable multiorgan donors. The samples were obtained from veins draining the spleen, gut, and liver, and from the periphery. Employing polyacrylamide-gel electrophoresis in combination with crossed immunoelectrophoresis we were able to identify the four molecular species in all samples. Apo-transferrin was the predominant molecular species while diferric transferrin was the least abundant (P less than 0.01). The monoferric species were dominated by the acid-stable form (iron loading on the C-terminal end of the molecule) with ratios C/N from 1.2 (splenic and posthepatic serum) to 1.5-1.6 in mesenteric or peripheral samples respectively. We conclude from our study that it is unlikely that the monoferric transferrin species play a role in directing internal iron exchange and that in accordance with most of the literature the acid-stable form is preferentially loaded under physiological conditions of iron metabolism.

Correct folding of circularly permuted variants of a beta alpha barrel enzyme in vivo

An important question in protein folding is whether the natural amino and carboxyl termini and the given order of secondary structure segments are critical to the stability and to the folding pathway of proteins. Here it is shown that two circularly permuted versions of the gene of a single-domain beta alpha barrel enzyme can be expressed in Escherichia coli. The variants are enzymically active and are practically indistinguishable from the original enzyme by several structural and spectroscopic criteria, despite the creation of new termini and the cleavage of a surface loop. This novel genetic approach should be useful for protein folding studies both in vitro and in vivo.