Tumor targeting by a multivalent single-chain Fv (scFv) anti-Lewis Y antibody construct

The use of single-chain variable fragment (scFv) constructs has been investigated in cancer radioimmunotherapy (RIT) and radioimmunodetection, as these molecules permit rapid tumor penetration and clearance from the serum relative to whole IgG. Multimerization of scFv constructs has demonstrated improvements in functional affinity (i.e., avidity) and maximal tumor uptake. In this paper, we report the first biodistribution and pharmacokinetics studies of a noncovalent, direct-linked scFv (V(L)-0-V(H)) trimeric/tetrameric "multimer" of the anti-Lewis Y monoclonal antibody, hu3S193. The in vitro binding and in vivo biodistribution of the hu3S193 multimer was characterized alongside the hu3S193 F(ab')(2) following radiolabeling with the Indium-111 ((111)In) radioisotope. Immunoreactivities of the radiolabeled multimer and F(ab')(2) were 73% and 53.2%, and binding affinities (K(a)) were 1.58 x 10(7) M(1) and 4.31 x 10(6) M (1) for the multimer and F(ab')(2), respectively. Maximal tumor uptake in Le(y)-positive MCF-7 breast cancer xenografted BALB/c nude mice was 12.6 +/- 2.5 percent injected dose/per gram (%ID/g) at 6 hours postinjection for the multimer and 15.7 +/- 2.1 %ID/g at 24 hours postinjection for the F(ab')(2). However, limited in vitro stability and high renal localization of radiolabeled constructs were observed, which, despite the observed tumor targeting of the hu3S193 multimer, most likely preclude its use in RIT and imaging modalities.

Storage and preparation of samples for erythropoietin radioimmunoassay

The evaluation of a radioimmunoassay for erythropoietin developed using recombinant material as immunogen and radiotracer is presented. A series of serum samples prepared and stored under varying conditions showed that immunoreactive erythropoietin levels were stable at room temperature for at least 10 days and at -20 degrees C for 5 months. The optimum time for separating sera from samples was between 6 and 24 h after venepuncture. Serum EPO values were significantly higher than those measured in heparin or potassium EDTA plasma.

Spiking of serum specimens with exogenous reporter peptides for mass spectrometry based protease profiling as diagnostic tool

Serum is a difficult matrix for the identification of biomarkers by mass spectrometry (MS). This is due to high-abundance proteins and their complex processing by a multitude of endogenous proteases making rigorous standardisation difficult. Here, we have investigated the use of defined exogenous reporter peptides as substrates for disease-specific proteases with respect to improved standardisation and disease classification accuracy. A recombinant N-terminal fragment of the Adenomatous Polyposis Coli (APC) protein was digested with trypsin to yield a peptide mixture for subsequent Reporter Peptide Spiking (RPS) of serum. Different preanalytical handling of serum samples was simulated by storage of serum samples for up to 6 h at ambient temperature, followed by RPS, further incubation under standardised conditions and testing for stability of protease-generated MS profiles. To demonstrate the superior classification accuracy achieved by RPS, a pilot profiling experiment was performed using serum specimens from pancreatic cancer patients (n = 50) and healthy controls (n = 50). After RPS six different peak categories could be defined, two of which (categories C and D) are modulated by endogenous proteases. These latter are relevant for improved classification accuracy as shown by enhanced disease-specific classification from 78% to 87% in unspiked and spiked samples, respectively. Peaks of these categories presented with unchanged signal intensities regardless of preanalytical conditions. The use of RPS generally improved the signal intensities of protease-generated peptide peaks. RPS circumvents preanalytical variabilities and improves classification accuracies. Our approach will be helpful to introduce MS-based proteomic profiling into routine laboratory testing.

Influence of varying doses of granulocyte-macrophage colony-stimulating factor on pharmacokinetics and antibody-dependent cellular cytotoxicity

Recombinant granulocyte-macrophage colony-stimulating factor (GM-CSF) is used in immunotherapy for correction of neutropoenia. The optimal dose for activation of immune functions and the pharmacokinetics following repeated administrations is less analysed in depth. In this study, the pharmacokinetics and the effects on haematological functions and antibody-dependent cellular cytotoxicity (ADCC) were analysed in 50 patients with metastatic colorectal carcinoma receiving monoclonal antibody based therapy in combination with Escherichia coli-derived GM-CSF (molgramostim) administered s.c. once daily for 10 days every month over a period of 4 months. Thirty-three patients received a GM-CSF dose of 200-250 microg/m(2)/day. Seventeen patients received GM-CSF doses varying between 65 and 325 microg/m(2)/day in the different treatment cycles. Serum GM-CSF concentration was measured (ELISA) before and 3-4 h after (peak serum concentration) GM-CSF administration days 1, 5 and 10. Prior to therapy, GM-CSF was not detectable in serum. Following repeated daily administrations, the peak serum concentration of GM-CSF gradually decreased on days 5 and 10 compared to day 1 (P < 0.05). During a 10-day treatment cycle, the total number of leukocytes, neutrophils, eosinophils, monocytes and lymphocytes increased. A dose-dependent increment in total white blood cell count and neutrophils was observed. The total numbers of GM-CSF receptor (alpha-subunit) expressing cells (granulocytes and monocytes) increased significantly during treatment while a transient decline in expression intensity was observed at day 5, suggesting a receptor-mediated removal of GM-CSF as a mechanism for the elimination of GM-CSF from circulation. ADCC of peripheral mononuclear cells was decreased at day 10 compared to baseline. An inverse correlation between the dose and ADCC was noted. The data might indicate that high doses of GM-CSF may have a negative impact on ADCC.

Rotational thrombelastometry for the bedside monitoring of recombinant hirudin

BACKGROUND

Recombinant hirudin is used as an alternative anticoagulant, particularly in patients with heparin-induced thrombocytopenia type II. However, bedside monitoring for hirudin is not available. The present study aims to evaluate rotational thrombelastometry regarding its suitability to detect the effects of recombinant hirudin on whole blood coagulation. Hirudin was added to whole blood samples from healthy donors (n=5) and thrombelastometry variables resulting from activation of samples with tissue factor, ellagic acid, and ecarin were determined.

METHODS

Hirudin (0.1-10 microg/ml) was added to citrated blood. Thereafter, rotational thrombelastometry was performed by initiating coagulation via recalcification and addition of tissue factor, ellagic acid, and ecarin, respectively, using the commercially available assays.

RESULTS

In the absence of hirudin, clotting times (CT) induced by ellagic acid, tissue factor, and ecarin, respectively, were 141.7+/-18.0, 54.0+/-7.6, and 64.5+/-4.1 s. Increasing concentrations of hirudin led to dose-dependent prolongation of the clotting time with the three activators. All assays were capable to detect hirudin concentrations in the range of 0.5-5 microg/ml. At a final hirudin concentration of 1 microg/ml, clotting time increased to 268.0+/-25.1, 84.0+/-9.3, and 107.5+/-9.9 s, respectively, with the above-mentioned activators. The other thrombelastographic variables, including clot formation time, angle alpha, and maximum clot firmness, were not altered by hirudin at concentrations up to 5 microg/ml.

CONCLUSIONS

Our study demonstrates the suitability of rotational thrombelastometry to detect anticoagulant effects of recombinant hirudin.

Delivery of DNA into skeletal muscle in large animals

Increased transgene expression after plasmid transfer to the skeletal muscle is obtained with electroporation in many species, but optimal conditions for individual species and muscle group are not well defined. Using a muscle-specific plasmid driving the expression of a secreted embryonic alkaline phosphatase (SEAP) reporter gene, we have optimized the electroporation conditions in a large mammal model, i.e. pig. The parameters optimized include electric field intensity, number of pulses, lag time between plasmid injection and electroporation, and plasmid delivery volume. Constant current pulses, between 0.4 and 0.6 A, applied 80 s after the injection of 0.5 mg SEAP-expressing plasmid in a total formulation volume of 2 mL produced the highest expression in semimembranosus muscle in pigs. These results could be extrapolated for a different muscle group in pigs, the biceps femoris, and may be an evaluation starting point for large muscle in veterinary species or humans (see Note 1 ).

Pulmonary sequestration with elevated serum level of progastrin-releasing peptide

A 74-year-old woman with rheumatoid arthritis was referred for a mass incidentally noted on chest radiograph. Chest CT scan showed cystic lesions in the right lower lobe. The lesion was evaluated as bronchiectasis, and she was followed up. Three years after the initial presentation, the appearance of the lesion had changed significantly and an elevated air-fluid level in the cystic structures was shown on chest CT scan. The preoperative serum progastrin-releasing peptide (proGRP) level was elevated (108.0 pg/ml; normal: <50 pg/ml). Histopathological specimen obtained by standard lower lobectomy confirmed that the lesion was an intralobar pulmonary sequestration. In the resected lobe, there was no malignant finding, but there were neuroendocrine tumorlet cells, which were positive for proGRP. One month after the resection, the serum proGRP level returned to normal. No pulmonary sequestration with high levels of proGRP has been reported, and this is the first case with elevated serum levels of proGRP.

Type 1 diabetes associated with acquired generalized lipodystrophy and insulin resistance: the effect of long-term leptin therapy

CONTEXT

Acquired generalized lipodystrophy (AGL) is marked by severe insulin resistance and hypertriglyceridemia. Rarely, AGL and type 1 diabetes (T1D) coexist.

OBJECTIVE

Our objective was to describe the response to leptin therapy in patients with coexisting AGL and T1D and to document the autoimmune diseases associated with AGL.

DESIGN AND SETTING

We conducted an open-label prospective study at the Clinical Research Center of the National Institutes of Health.

PATIENTS

Participants included 50 patients with generalized or partial lipodystrophy (acquired or congenital); two patients had both AGL and T1D.

INTERVENTION

Patients were treated with 12 months of recombinant human leptin administration to achieve high-normal serum concentrations.

RESULTS

Two patients had both AGL and T1D. The first was diagnosed with T1D at age 8 yr. Beginning at age 11 yr, he developed generalized lipodystrophy, elevated transaminases, and poor glycemic control [hemoglobin A 1c (HbA 1c) 10.7%] despite markedly increased insulin requirements (3.3-5 U/kg.d). Further evaluation revealed hypoleptinemia and hypertriglyceridemia. At age 15 yr, leptin therapy was initiated, and after 1 yr, his insulin requirements fell to 1 U/kg.d, his glycemic control improved (HbA 1c 8.4%), and both his triglycerides and transaminases normalized. The second patient developed concurrent AGL and T1D at age 6 yr. Despite insulin doses of up to 32 U/kg.d, she developed poor glycemic control (HbA 1c 10.6%), hypertriglyceridemia (2984 mg/dl), elevated transaminases, and nonalcoholic steatohepatitis. At age 13 yr, leptin therapy was started, and after 1 yr, her glycemic control improved (HbA 1c 7.3%) and her insulin requirements decreased (17 U/kg.d). Her triglycerides remained elevated but were improved (441 mg/dl).

CONCLUSIONS

Long-term recombinant leptin therapy is effective in treating the insulin resistance of patients with the unusual combination of T1D and AGL.

Effect of Acute Administration of Recombinant Human Leptin during the Neonatal Period on Body Temperature and Endocrine Profile of the Piglet

BACKGROUND

Leptin is produced predominantly by white adipocytes; in adults it regulates appetite and energy expenditure but its role in the neonate remains to be fully established.

OBJECTIVES

To examine the effects of acute administration of recombinant human leptin on the endocrine profile and thermoregulation of neonatal pigs.

METHODS

24 pairs of siblings (n = 48) were administered with either a single dose (4 microg ml(-1) kg(-1) body weight) of leptin (L: n = 24) or a placebo (P: n = 24) on day 6 of neonatal life. Rectal temperature was recorded, and tissue samples were taken at 1 (n = 12), 2 (n = 12), 4 (n = 12) or 6 (n = 12) hours post-administration. Plasma concentrations of hormones and metabolites were determined in conjunction with messenger RNA (mRNA) for leptin and uncoupling protein-2.

RESULTS

Plasma leptin increased following leptin administration, and differences in concentrations of insulin, thyroxine and non-esterified fatty acids were observed between the two groups. Initially, rectal temperature decreased in L pigs but returned to start values by 1.5 h. This decline in rectal temperature was delayed in placebo animals, resulting in differences between treatments at 1.5 and 2 h.

CONCLUSIONS

Acute leptin administration alters the endocrine profile of pigs and influences the thermoregulatory ability of the neonate.

A comparative study of hFIX expression mediated by rAAV8 and rAAV1 administrated intramuscularly

BACKGROUND

Recombinant AAV serotype 8 (rAAV8) vector is relatively new for gene therapy. In this study, the hFIX expression mediated by rAAV8 injected intramuscularly was compared with that by rAAV1.

METHODS

rAAV8-hFIX or rAAV1-hFIX viruses were injected intramuscularly into two hind limbs of mice at doses of 5x10(10) gc and 2.5x10(12) gc (genome copy). The hFIX expression in the mouse plasma was detected by ELISA, APTT and Western blotting. The virus distribution was analyzed by immunohistochemical assay.

RESULTS

When the mice were infected with 5x10(10) gc virus, high levels of hFIX in the plasma of five rAAV8-hFIX virus-infected mice were detected 2 weeks after injection. A hFIX peak above 5000 ng/mL appeared between 2 and 6 weeks after injection. Relatively low levels of hFIX were detected in the plasma of rAAV1-hFIX virus-infected mice 2 weeks after injection. An hFIX peak above 3000 ng/mL appeared between 4 and 10 weeks after injection. However, much lower levels of hFIX were detected in mice infected with higher dose of rAAV8 virus. The hFIX in the mouse plasma was active biologically. The viruses were distributed mainly in the muscles of hind limbs.

DISCUSSION

Gene expression mediated by rAAV8 was sooner and stronger than that by rAAV1 after intramuscular administration. Inhibition might have been triggered markedly by rAAV8 at high doses.

Induction of interleukin-6 by hepatitis C virus core protein in hepatitis C-associated mixed cryoglobulinemia and B-cell non-Hodgkin's lymphoma

PURPOSE

Chronic hepatitis C carries the risk to develop mixed cryoglobulinemia (MC) and B-cell non-Hodgkin's lymphoma (B-NHL), possibly because viral antigens stimulate the host's inflammatory response via extracellular pattern recognition receptors (PRR). To clarify this issue, we studied whether recognition of hepatitis C virus (HCV) proteins by PRR is involved in the pathogenesis of HCV-associated MC or B-NHL.

EXPERIMENTAL DESIGN

Peripheral blood mononuclear cells of patients with HCV-associated B-NHL (n = 12), MC (n = 14), uncomplicated hepatitis C (n = 12), and healthy volunteers (n = 12) were incubated with the recombinant HCV proteins E2, core, and NS3 to study induction of cytokine production, stimulation of B-cell proliferation, and immunoglobulin secretion. In addition, serum levels of interleukin-6 (IL-6) were measured by ELISA.

RESULTS

HCV core was the only studied protein, which induced production of IL-6 and IL-8 in CD14(+) cells. IL-6 induction was mediated via Toll-like receptor 2 (TLR2) and lead to increased B-cell proliferation in vitro. TLR2 expression on monocytes and IL-6 serum concentrations were increased in all groups of HCV-infected patients compared with healthy controls and were highest in MC (P < 0.05).

CONCLUSIONS

Increased secretion of IL-6 via stimulation of TLR2 by HCV core protein may play a role in the pathogenesis of hepatitis C-associated MC and B-NHL.

The fasting polypeptide FGF21 can enter brain from blood

FGF21 recently has been proposed as a missing link in the biology of fasting, raising the question of whether it directly reaches the brain. We used multiple time-regression analysis to quantify the influx rate of this polypeptide across the blood-brain barrier (BBB), size-exclusion chromatography to examine degradation, capillary depletion to differentiate entry into brain parenchyma from retention in the microvasculature, and measurement of efflux rate to determine a possible confounding effect on measurement of entry. FGF21 was 94% intact in serum and 75% in brain 10 min after intravenous bolus delivery. Its influx rate was 0.23+/-0.12 microl/g-min, nearly four times faster than that of the vascular marker albumin. At 10 min, about 0.5% of the administered FGF21 was present in a gram of brain tissue. Of this, 70% reached the parenchyma of the brain. Co-injection of excess FGF21 failed to inhibit the influx, showing a lack of saturation. Efflux, which occurred at the same rate as the bulk reabsorption of cerebrospinal fluid, also was not saturable. In summary, FGF21 shows significant, non-saturable, unidirectional influx across the BBB.

Tumor angiogenesis is associated with plasma levels of stromal-derived factor-1alpha in patients with multiple myeloma

PURPOSE

Multiple myeloma is an incurable hematologic malignancy characterized by increased bone marrow angiogenesis and extensive lytic bone disease. We have previously shown that elevated levels of stromal-derived factor-1alpha (SDF-1alpha) in peripheral blood plasma are associated with osteolysis in multiple myeloma patients. We have now examined whether SDF-1alpha levels also correlate with angiogenesis.

EXPERIMENTAL DESIGN

We examined the contribution of multiple myeloma plasma cell-derived SDF-1alpha in the stimulation of in vitro angiogenesis using a tube formation assay. We also collected trephine and peripheral blood plasma samples from patients with multiple myeloma to analyze microvessel density and SDF-1alpha levels, respectively.

RESULTS

We show that multiple myeloma plasma cell line-derived conditioned medium containing SDF-1alpha stimulates in vitro angiogenesis. In addition, in a large cohort of patients with multiple myeloma and its precursor condition monoclonal gammopathy of undetermined significance, we confirm previous findings that plasma cell burden correlates with both angiogenesis and plasma levels of SDF-1alpha. We now extend these observations and show the novel finding that peripheral blood plasma levels of SDF-1alpha positively correlate with the degree of bone marrow angiogenesis in multiple myeloma and monoclonal gammopathy of undetermined significance patients.

CONCLUSIONS

High levels of SDF-1alpha produced by multiple myeloma plasma cells promote osteolysis and bone marrow angiogenesis. Therefore, we propose that inhibition of SDF-1alpha may be an effective mechanism by which angiogenesis and osteolysis can be reduced in multiple myeloma patients.

[Promoting mechanism of enhancers and transport pathway of large hydrophilic molecular across nasal epithelium studied by ESR and CLSM technologies]

The aim of this study is to investigate absorption-promoting mechanism of enhancers and the transport pathway of large hydrophilous molecular across rat nasal epithelium by electron spin resonance (ESR) and confocal laser scanning microscopy (CLSM) technologies. In the experiment, recombinant hirudin-2 (rHV2) was chosen as a large hydrophilic molecular model drug. After nasal administration in rats the bioavailability of rHV2 with or without various enhancers was compared. The effects of enhancers on membrane lipid fluidity and protein conformation were measured with 5-deoxyl-stearic acid (5-DSA), 16-deoxyl-stearic acid (16-DSA) and 3-maleidoproxyl (MSL) labeling ESR. The effects of enhancers on cytoskeletal F-actin of rat nasal epithelium and FITC-rHV2 transport pathway across rat nasal epithelium were performed by CLSM combined with fluorescence labeling. 0.5% Chitosan (CS), 5% hydroxyl-propyl-beta-cyclodextrin ( HP-beta-CD) and 1% ammonium glycyrrhizinate (AMGZ) were all able to significantly increase the nasal absorption of rHV2. CS could result in the paracellular pathway transport of FITC-rHV2 which seemed related to a transient effect on tight junctions. HP-beta-CD could cause paracellular and transcellular route transport of FITC-rHV2 by influencing upon membrane protein as well as lipid fluidity. AMGZ seemed to enhance the transcellular route transport of FITC-rHV2, and could exert some influence on membrane protein but not on lipid fluidity. So how it brought out this result needs further research. Present experiment may become a useful reference for promoting mechanism of enhancers and the transport pathway of large hydrophilic molecular across nasal epithelium research.

Validation of the growth hormone (GH)-dependent marker method of detecting GH abuse in sport through the use of independent data sets

CONTEXT

The detection of exogenously administered growth hormone (GH) poses a formidable challenge but a detection method based on the measurement of two GH-dependent markers, IGF-I and type 3 pro-collagen (P-III-P) has been proposed. The measurement of multiple markers in conjunction with discriminant functions can improve the sensitivity and specificity of detection compared with single marker analysis.

OBJECTIVE

To provide further validation of the GH-dependent marker approach.

DESIGN

Analysis of discriminant function scores for GH detection on independent datasets.

SETTING

Two independent (GH-2000 and Kreischa) double blind, placebo controlled, hGH administration studies.

SUBJECTS

Healthy active male volunteers.

INTERVENTION

GH-2000 proposed a discriminant function involving IGF-I and P-III- P while the Kreischa function involved IGF-I, P-III-P and IGFBP-3. After adjustment for assay differences the formulae were applied to the other dataset.

OUTCOME MEASURES

Ability to detect GH use in independent datasets using a predefined specificity of approximately 1 in 10000.

RESULTS

The GH-2000 formula was able to detect 90% of those receiving GH in the Kreischa study at one or more time points during the study period. This sensitivity was similar to that obtained on the original GH-2000 dataset. The Kreischa formula correctly identified 41% of individuals receiving GH in the GH-2000 study.

CONCLUSIONS

The study provides further validation that the test proposed by GH-2000 based on IGF-I and P-III-P concentrations can be used to detect subjects receiving exogenous GH.

Comparison of coagulant activity of factor VII and activated factor VII activity assays when used for determination of recombinant activated factor VII levels in plasma

Two assays [coagulant activity of factor VII (FVII:C) and activated factor VII (FVIIa) activity] are currently available for the assessment of factor VII and FVIIa pharmacokinetics. This article presents the results of a comparison of the two assays when applied both in vitro as well as during clinical pharmacokinetic trials of recombinant FVIIa (rFVIIa) administered to healthy individuals and haemophilia patients. The in-vitro data showed that, for the FVII:C assay, plasma samples do not dilute in parallel. For the FVIIa activity assay, dilutions of samples are both parallel and linear with different dilutions of the calibrator. Moreover, intra-assay variation was found to be smaller for the FVIIa activity assay than for the FVII:C assay. When adding different amounts of rFVIIa (0-6 microg/ml) to normal plasma, a mean specific activity of rFVIIa of 48.6 U/mug was observed on applying the FVII:C assay; however, the specific activity decreased with increasing levels of rFVIIa. For the FVIIa activity assay, the mean specific activity was 45.4 IU/mug. Direct comparison of the two activity assays showed that no simple conversion between FVII:C and FVIIa activity measurements are possible. When applying the two assays for pharmacokinetic assessments in two clinical trials, statistically significant different estimates for the area under the curve, half-life, clearance and volume of distribution were obtained. In conclusion, for evaluation of rFVIIa pharmacokinetic properties, activity should be measured with the FVIIa activity assay - which is a more specific and reliable assay of the two available factor VII activity assays, especially when assessing low activity levels.

Erythrocyte adenylate kinase deficiency: characterization of recombinant mutant forms and relationship with nonspherocytic hemolytic anemia

OBJECTIVE

Red cell adenylate kinase (AK) deficiency is a rare hereditary erythroenzymopathy associated with moderate to severe nonspherocytic hemolytic anemia and, in some cases, with mental retardation and psychomotor impairment. To date, diagnosis of AK deficiency depends upon demonstration of low enzyme activity in red blood cells and detection of mutations in AK1 gene. To investigate the molecular bases of the AK deficiency, we characterized five variants of AK1 isoenzyme-bearing mutations (118G>A, 190G>A, 382C>T, 418-420del, and 491A>G) found in AK-deficient patients with chronic hemolytic anemia.

MATERIALS AND METHODS

The complete AK1 cDNA was obtained by standard procedures and using as template the reticulocyte RNA. The cDNA was cloned in a plasmid vector and the enzyme was expressed in Escherichia coli BL21(DE3)pLysS, and purified by standard protocols to homogeneity. DNA mutants bearing point mutations were obtained from the cloned wild-type cDNA using standard methods of site-directed mutagenesis, whereas the DNA mutant with deletion of codon 140 was obtained by a two-step method.

RESULTS

Four mutant enzymes (Gly40Arg, Gly64Arg, Arg128Trp, Asp140del) were severely affected in activity, displaying a catalytic efficiency of four orders of magnitude lower than the wild-type; one (Tyr164Cys) was grossly perturbed in protein stability.

CONCLUSIONS

The altered properties displayed by the mutant enzymes support the cause-effect relationship between AK1 mutations and hemolytic anemia.

Differences in functional activity and antigen expression of granulocytes primed in vivo with filgrastim, lenograstim, or pegfilgrastim

BACKGROUND

Granulocyte-colony-stimulating factor (G-CSF) is known to affect functional activity and antigen expression of neutrophil granulocytes. Beside nonglycosylated filgrastim and glycosylated lenograstim, pegylated filgrastim (pegfilgrastim) has recently been introduced for single administration into clinical use.

STUDY DESIGN AND METHODS

Here, granulocytes from 27 patients with nonmyeloid malignancies were compared functionally (migration, reactive oxygen species production, and G-CSF serum levels) and phenotypically (cell surface antigen expression) before and after G-CSF administration.

RESULTS

After exposure to G-CSF, chemotaxis was reduced significantly in the filgrastim group. Immunophenotypically, in vivo G-CSF-primed granulocytes were more mature in the lenograstim than in the filgrastim and to lesser extent in the pegfilgrastim groups as shown by the expression profile for CD11b, CD14, and CD16. Of note, G-CSF serum levels were similar among the groups.

CONCLUSION

Our data suggest that granulocytes exposed to glycosylated G-CSF in vivo seem to resemble more closely their steady-state phenotype than after treatment with nonglycosylated and to lesser extent pegylated G-CSF.

Prevention of experimental autoimmune myasthenia gravis by rat Crry-Ig: A model agent for long-term complement inhibition in vivo

Despite its vital role in innate immunity, complement is involved in a number of inflammatory pathologies and has therefore become a therapeutic target. Most agents generated for anti-complement therapy have short half-lives in plasma, or have been of mouse or human origin, thereby limiting their use either to murine models of disease or to short-term therapy. Here we describe the generation of a long-acting rat therapeutic agent based on the rat complement inhibitor, Crry. Characterisation of various soluble forms of Crry demonstrated that the amino-terminal four short-consensus repeat domains were required for full regulatory and C3b-binding activities. Fusion of these domains to rat IgG2a Fc generated an effective complement inhibitor (rCrry-Ig) with a circulating half-life prolonged from 7 min for Crry alone to 53 h for rCrry-Ig. Systemic administration of rCrry-Ig over 5 weeks generated a weak immune response to the recombinant agent, however this was predominantly IgM in nature and did not neutralise Crry function or cause clearance of the agent from plasma. Administration of rCrry-Ig completely abrogated clinical disease in a rat model of myasthenia gravis whereas soluble Crry lacking the immunoglobulin Fc domain caused a partial response. rCrry-Ig not only ablated clinical disease, but also prevented C3 and C9 deposition at the neuromuscular junction and inhibited cellular infiltration at this site. The long half-life and low immunogenicity of this agent will be useful for therapy in chronic models of inflammatory disease in the rat.

Recombinant hirudin for cardiopulmonary bypass anticoagulation: a randomized, prospective, and heparin-controlled pilot study

BACKGROUND

Lepirudin, a recombinant hirudin, is a direct acting thrombin inhibitor that has been used as a heparin alternative in patients with heparin-induced thrombocytopenia requiring on-pump cardiac surgery. To evaluate the efficacy, safety, and clinical utility of lepirudin as a cardiopulmonary bypass (CPB) anticoagulant, we compared lepirudin with heparin in a routine CPB setting.

METHODS

Twenty patients were randomly assigned to receive lepirudin (0.25 mg/kg b. w. bolus and 0.2 mg/kg b. w. added to the CPB priming) or heparin (400 U/kg b. w. bolus) with protamine reversal. Lepirudin and heparin anticoagulation during CPB was monitored using the ecarin clotting time or ACT, respectively and additional lepirudin (5 mg) or heparin (5000 U) boluses were administered.

RESULTS

The CPB circuit was performed in both groups without thromboembolic complications. Median blood loss during the first 36 hours was statistically higher ( P = 0.007) in the lepirudin group (1.226 +/- 316 ml) compared to the heparin group (869 +/- 189 ml). One patient of the lepirudin group developed pulmonary embolism 24 hours after surgery. This patient was tested homozygous for the FV-Leiden mutation.

CONCLUSION

Lepirudin provides effective CPB anticoagulation but induces a higher postoperative blood loss than heparin. Lepirudin should be restricted to patients undergoing CPB who cannot be exposed to heparin.

Value of tumour and inflammatory markers in lung cancer

The aim of this study was to evaluate the individual diagnostic utility of tumour and inflammatory markers in patients with different pulmonary diseases. The usefulness of neuron-specific enolase (NSE), carcino-embryonic antigen (CEA), serum pro-gastrin releasing peptide (ProGRP) and CYFRA 21-1, as tumour markers, and C-reactive protein (CRP) and tumour necrosis factor-alpha (TNFalpha) as inflammatory markers for diagnosis, treatment and monitoring of patients with different pulmonary afflictions was investigated. Eighty healthy individuals were also included. Serum samples were also obtained from 20 patients suffering from bronchitis, 20 with lung fibrosis and 30 with sarcoidosis. Moreover, serum marker levels were analyzed in 139 patients with different pulmonary malignancies: 29 patients with adenocarcinoma, 30 patients with squamous cell carcinoma, 80 patients with small cell lung cancer (SCLC). All tumour markers showed significantly elevated values in malignant diseases. The levels of ProGRP in patients with benign diseases were significantly higher than those in the healthy group (35.4 +/- 6.6 compared with 21.3 +/- 9.2 pg/ml respectively). The serum ProGRP levels were elevated in SCLC patients (1673.9 +/- 706 pg/ml). The elevation was significantly higher than that of the benign reference group. The acute phase response had a wide range in patients with malignant tumours. Serum CRP levels were significantly higher in patients with SCLC (38.5 +/- 7.6 mg/dl) than in the benign reference group. In conclusion, when serum tumour markers are abnormally elevated in patients with lung cancer, CEA, CYFRA 21-1, NSE and ProGRP are useful clinical markers, good indicators of disease extent and may have important prognostic value. In particular, NSE and ProGRP have a very high sensitivity for SCLC detection.

Treatment failure related to intrathecal immunoglobulin M (IgM) synthesis, cerebrospinal fluid IgM, and interleukin-10 in patients with hemolymphatic-stage sleeping sickness

Human African trypanosomiasis treatment is stage dependent, but the tests used for staging are controversial. Central nervous system involvement and its relationship with suramin treatment failure were assessed in 60 patients with parasitologically confirmed hemolymphatic-stage Trypanosoma brucei gambiense infection (white blood cell count of or=1.9 mg/liter (OR, 11.7; 95% CI, 2.7 to 50), a CSF end titer by the LATEX/IgM assay of >or=2 (OR, 10.4; 95% CI, 2.5 to 44), and a CSF interleukin-10 concentration of >10 pg/ml (OR, 5; 95% CI, 1.3 to 20). The sensitivities of these markers for treatment failure ranged from 43 to 79%, and the specificities ranged from 74 to 93%. The results show that T. brucei gambiense-infected patients who have signs of neuroinflammation in CSF and who are treated with drugs recommended for use at the hemolymphatic stage are at risk of treatment failure. This highlights the need for the development and the evaluation of accurate point-of-care tests for the staging of human African trypanosomiasis.

The preventative role of growth hormone on acute liver injury induced by cardiopulmonary bypass in a rat model

OBJECTIVE

Cardiopulmonary bypass (CPB)-induced acute liver injury is a life-threatening complication after cardiac surgery and is thought to be associated with inflammatory response and acute-phase response (APR). Recombinant human growth hormone (rhGH) can modulate the APR and inflammatory response. Here, we tested the protective effect of GH on CPB-induced liver injury in the rat.

METHODS

Adult male Sprague-Dawley rats (group G, received 2.5 mg/kg of rhGH intramuscularly at 8a.m. every 24h for 3 days and just before the initiation of CPB; group C served as control) underwent CPB (120 min, 120 ml/kg per minute, 34 degrees C) and were killed 3h after the termination of CPB.

RESULTS

Administration of rhGH markedly increased serum insulin-like growth factor (IGF)-I and IGF-I-binding protein (IGFBP)-3 compared with group C. Group G showed significantly lower serum concentrations of alanine aminotransferase and total bilirubin after CPB termination. Those receiving rhGH demonstrated a significant increase in serum prealbumin and serum transferrin and a marked decrease in serum amyloid A and serum C-reactive protein compared with group C. rhGH significantly decreased serum tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta), whereas no changes were found for serum IL-6 and IL-10 compared with group C. rhGH significantly increased total liver protein content, hepatocyte proliferation, and decreased hepatocyte apoptosis versus group C.

CONCLUSIONS

These results suggest that GH administration in rats seems to play a preventative role in acute liver injury associated with CPB via the decrease in acute-phase proteins, proinflammatory cytokines TNF-alpha and IL-1beta, and hepatocyte apoptosis, which is associated with increase in constitutive hepatic proteins, total liver protein content, and hepatocyte proliferation.

Vaccination with NY-ESO-1 protein and CpG in Montanide induces integrated antibody/Th1 responses and CD8 T cells through cross-priming

The use of recombinant tumor antigen proteins is a realistic approach for the development of generic cancer vaccines, but the potential of this type of vaccines to induce specific CD8(+) T cell responses, through in vivo cross-priming, has remained unclear. In this article, we report that repeated vaccination of cancer patients with recombinant NY-ESO-1 protein, Montanide ISA-51, and CpG ODN 7909, a potent stimulator of B cells and T helper type 1 (Th1)-type immunity, resulted in the early induction of specific integrated CD4(+) Th cells and antibody responses in most vaccinated patients, followed by the development of later CD8(+) T cell responses in a fraction of them. The correlation between antibody and T cell responses, together with the ability of vaccine-induced antibodies to promote in vitro cross-presentation of NY-ESO-1 by dendritic cells to vaccine-induced CD8(+) T cells, indicated that elicitation of NY-ESO-1-specific CD8(+) T cell responses by cross-priming in vivo was associated with the induction of adequate levels of specific antibodies. Together, our data provide clear evidence of in vivo cross-priming of specific cytotoxic T lymphocytes by a recombinant tumor antigen vaccine, underline the importance of specific antibody induction for the cross-priming to occur, and support the use of this type of formulation for the further development of efficient cancer vaccines.