Pharmacokinetics and biological activity in subcutaneous long-term administration of recombinant interferon-γ in cancer patients

Summary We have investigated the pharmacokinetics, tolerance, and biological activity of recombinant human interferon- (rHuIFN) administered subcutaneously to cancer patients. Twenty-one patients with lymphoma and metastatic cancer received rHuIFN (in doses of 0.1, 0.25, or 0.5 mg/m²) in two or three injections per week for up to 180 days. The most common adverse effects encountered were flu-like symptoms, fever and fatigue. The increase in body temperature after each administration ranged from 0 to 4°C depending on the individual patient, but was unrelated to the rHuIFN dose or its plasma concentration. The pharmacokinetic response of the patients after the two treatments showed a low intra-individual variability with respect to the plasma concentration/time profiles. However, as observed for the fever side-effect, the interindividual variation (CV >50%) was high for the parameters area under the data points (AUC_0-t ) and maximum plasma concentration (c _max). Despite this high interindividual variability, the mean values obtained for AUC_0-t andc _max after s.c. injection of rHuIFN were approximately proportional to the dose administered: the injection of 0.1, 0.25 or 0.5 mg/m² rHuIFN resulted in AUC_0-t values of 15.4, 31.5 or 69.6 ng h/ml, respectively andc _max was found to be 1.0, 2.4 and 4.9 ng/ml, respectively. With this s.c. administration protocol, objective antitumour responses were observed in two patients, but there was no partial or complete remission.     

Adjuvant-guided type-1 and type-2 immunity: infectious/noninfectious dichotomy defines the class of response

Traditionally, protein Ags have been injected in CFA (oil with inactivated mycobacteria) to induce immunity and with IFA (oil alone) to induce tolerance. We report here that injection of hen eggwhite lysozyme, a prototypic Ag, in CFA-induced and IFA-induced pools of hen eggwhite lysozyme-specific memory T cells of comparable fine specificity, clonal size, and avidity spectrum, but with type-1 and type-2 cytokine signatures, respectively. This adjuvant-guided induction of virtually unipolar type-1 and type-2 immunity was observed with seven protein Ags and in a total of six mouse strains. Highly polarized type-1 and type-2 immunity are thus readily achievable through the choice of adjuvant, irrespective of the genetic bias of the host and of the nature of the protein Ag. This finding should have far-reaching implications for the development of vaccines against infectious and autoimmune diseases. Furthermore, our demonstration that Ag injected with IFA is as strongly immunogenic for T cells as it is with CFA shows that the presence of the mycobacteria determines not the priming of naive T cells through the second-signal link but the path of downstream differentiation toward CD4 memory cells that express either type-1 or type-2 cytokines.     

An automatic enzymatic determination of glycogen in a continuous-flow system without interference of free glucose.

An autoanalyzer system for enzymatic determination of glycogen is described. Free glucose is eliminated by hexokinase/glucose-6-phosphate dehydrogenase. Glycogen is hydrolyzed by amylo-1,6-glycosidase at pH 4,8, and the resulting glucose is dialyzed and determined by the hexokinase/glucose-6-phosphate dehydrogenase reaction.     

Anatomy of the stomatogastric nervous system associated with the foregut in Drosophila melanogaster and Calliphora vicina third instar larvae

The stomatogastric nervous system (SNS) associated with the foregut was studied in 3rd instar larvae of Drosophila melanogaster and Calliphora vicina (blowfly). In both species, the foregut comprises pharynx, esophagus, and proventriculus. Only in Calliphora does the esophagus form a crop. The position of nerves and neurons was investigated with neuronal tracers in both species and GFP expression in Drosophila. The SNS is nearly identical in both species. Neurons are located in the proventricular and the hypocerebral ganglion (HCG), which are connected to each other by the proventricular nerve. Motor neurons for pharyngeal muscles are located in the brain not, as in other insect groups, in the frontal ganglion. The position of the frontal ganglion is taken by a nerve junction devoid of neurons. The junction is composed of four nerves: the frontal connectives that fuse with the antennal nerves (ANs), the frontal nerve innervating the cibarial dilator muscles and the recurrent nerve that innervates the esophagus and projects to the HCG. Differences in the SNS are restricted to a crop nerve only present in Calliphora and an esophageal ganglion that only exists in Drosophila. The ganglia of the dorsal organs give rise to the ANs, which project to the brain. The extensive conformity of the SNS of both species suggests functional parallels. Future electrophysiological studies of the motor circuits in the SNS of Drosophila will profit from parallel studies of the homologous but more accessible structures in Calliphora.     

Naturally Occurring Alpha-Synuclein Autoantibodies in Parkinson’s Disease: Sources of (Error) Variance in Biomarker Assays

Alpha-synuclein (α-Syn) plays a pivotal role in the pathophysiology of Parkinson’s disease (PD), which can partly be modulated by innate and adaptive immune functions, and vice versa. Here, naturally occurring α-Syn autoantibodies (α-Syn-nAbs) may be effective against α-Syn pathoetiology and may serve as a PD biomarker. However, serum and cerebrospinal fluid α-Syn-nAbs levels still lack consistent evidence as required for a reliable PD biomarker. Serum and cerebrospinal fluid α-Syn-nAbs levels of 66 PD patients and 69 healthy controls were assessed using a validated ELISA assay. Moreover, potential sources of error variance including unspecific ELISA background signals, free serum hemoglobin concentrations, α-Syn plate coating procedures, and differences in α-Syn-nAbs standards, were investigated. PD patients and controls did not differ in serum (p = .49) nor cerebrospinal fluid (p = .29) α-Syn-nAbs levels. Interestingly, free serum hemoglobin concentrations were negatively correlated with α-Syn-nAbs levels in controls (Spearman  = −.41, p<.001), but not in PD patients ( = .16, p = .21). ELISA α-Syn plate coating procedures impacted inter-assay variability (same day coating: 8–16%; coating on different days: 16–58%). α-Syn-nAbs standards from different purification batches differed regarding optical density measured in ELISAs suggesting differences in α-Syn affinity. While α-Syn-nAbs levels may represent a potential PD biomarker, several methodological issues have to be considered to increase reproducibility of α-Syn-nAbs findings. Further studies using standardized protocols minimizing sources of error variance may be necessary to establish a reliable PD α-Syn-nAbs biomarker.