HemaMax™, a recombinant human interleukin-12, is a potent mitigator of acute radiation injury in mice and non-human primates

HemaMax, a recombinant human interleukin-12 (IL-12), is under development to address an unmet medical need for effective treatments against acute radiation syndrome due to radiological terrorism or accident when administered at least 24 hours after radiation exposure. This study investigated pharmacokinetics, pharmacodynamics, and efficacy of m-HemaMax (recombinant murine IL-12), and HemaMax to increase survival after total body irradiation (TBI) in mice and rhesus monkeys, respectively, with no supportive care. In mice, m-HemaMax at an optimal 20 ng/mouse dose significantly increased percent survival and survival time when administered 24 hours after TBI between 8-9 Gy (p<0.05 Pearson's chi-square test). This survival benefit was accompanied by increases in plasma interferon-γ (IFN-γ) and erythropoietin levels, recovery of femoral bone hematopoiesis characterized with the presence of IL-12 receptor β2 subunit-expressing myeloid progenitors, megakaryocytes, and osteoblasts. Mitigation of jejunal radiation damage was also examined. At allometrically equivalent doses, HemaMax showed similar pharmacokinetics in rhesus monkeys compared to m-HemaMax in mice, but more robustly increased plasma IFN-γ levels. HemaMax also increased plasma erythropoietin, IL-15, IL-18, and neopterin levels. At non-human primate doses pharmacologically equivalent to murine doses, HemaMax (100 ng/Kg and 250 ng/Kg) administered at 24 hours after TBI (6.7 Gy/LD(50/30)) significantly increased percent survival of HemaMax groups compared to vehicle (p<0.05 Pearson's chi-square test). This survival benefit was accompanied by a significantly higher leukocyte (neutrophils and lymphocytes), thrombocyte, and reticulocyte counts during nadir (days 12-14) and significantly less weight loss at day 12 compared to vehicle. These findings indicate successful interspecies dose conversion and provide proof of concept that HemaMax increases survival in irradiated rhesus monkeys by promoting hematopoiesis and recovery of immune functions and possibly gastrointestinal functions, likely through a network of interactions involving dendritic cells, osteoblasts, and soluble factors such as IL-12, IFN-γ, and cytoprotectant erythropoietin.     

Characterisation of a serine proteinase from Penaeus vannamei haemocytes

Serine proteinases are involved, besides digestive role, in immune response processes. In addition to the typical serine proteinase domain, proteinases from arthropod haemocytes contain so-called clip domains which are believed to exert regulatory functions. Clones coding for clip domain-containing serine proteinases were isolated from both Penaeus vannamei and Penaeus monodon haemocyte cDNA libraries. These proteins have most of the structural characteristics of serine proteinase domain, but in the clip domain there are only four cysteines, whereas in most other clip domains there are six. Such structures are named pseudo-clip domains and apparently seem to be widely distributed in Penaeid shrimp. These proteinases were only expressed in haemocytes and not in muscles, hypodermis, heart, tail stalk, pleopods or hepatopancreas.     

Accumulation,localisation, and toxic effects of cadmium in the liverwort Lunularia cruciata

Summary. Accumulation, tissue and intracellular localisation, and toxic effects of cadmium were investigated in the liverwort Lunularia cruciata. The results of analyses carried out by atomic absorption spectrometry on single plants showed that the cadmium accumulation was dose- and time-dependent. Cadmium localisation was assessed by X-ray scanning electron microscopy microanalysis in gemmalings and in the different tissues of the thallus and by X-ray transmission electron microscopy microanalysis at the cellular level. The metal preferentially accumulated in the hyaline parenchyma and at the base of the gemma cups. Inside the cell, cadmium accumulated in the vacuoles and the cell wall. Metal accumulation was accompanied by a concomitant increase in sulphur content within the vacuoles of stressed cells. Gel-permeation chromatography showed that most of the cadmium was associated with a low-molecular-mass fraction eluting at a ratio of elution volume to void volume corresponding to that of phytochelatins. The excess of sulphur deposited in the vacuoles may well have been caused by the stress-induced synthesis of phytochelatins. At the ultrastructural level, sublethal concentrations of cadmium caused alterations of the fine structure of the cells, inducing marked alterations of the chloroplast structure. Cadmium also induced a dose-dependent inhibition of apical thallus growth and gemma germination.Correspondence and reprints: Department of Plant Biology, University Federico 11, via Foria 223, 80132 Naples, Italy.     

Age-related modifications in circulating IL-15 levels in humans

Aging is associated to a progressive establishing of a chronic inflammatory state linked to a continuous long exposure to antigens. Since IL-15 stimulates the proliferation of memory T cells and the immunosenescence is characterized by accumulation of memory T cells and exhaustion of naive T cells, we analyzed IL-15 levels in sera from 30 ultralongeval subjects with respect to those from young and old adults. IL-15 levels were assayed by immunoenzymatic methods. Ultralongeval subjects displayed significantly higher IL-15 levels with respect to both young and old controls. No statistical difference was found between old and young controls. These findings may explain, at least in part, the characteristic increase of memory cells in immunosenescence and the capacity of the immune system of centenarians to defend itself from infections through immune-inflammatory responses.     

Independent methods for evolutionary genetic dating provide insights into Y-chromosomal STR mutation rates confirming data from direct father–son transmissions

Five datasets consisting of samples jointly typed for Y-chromosomal Unique Event Polymorphism (UEP) and simple tandem repeat (STR) markers were re-examined with independent methods for dating the different UEP-defined lineages. We report on the results obtained with an original program which performs comparative dating (BARCODE) in comparison with coalescent analyses performed with BATWING under various prior conditions. For the first time these are equalized across datasets. We also report on the results concerning STR mutability as obtained with both methods. The dating results for the entire series of sub-haplogroups are highly correlated. Within coalescent analyses, dating-estimates under a wide range of priors tend to converge. As to STR mutation rates the main findings are: (1) large variations among loci within the same dataset with both methods, also when the same prior was used for all loci; (2) figures in most cases above 1×10⁻³ and often above 2×10⁻³; (3) a few loci that mutate differently across studies. These results closely match those obtained from direct observation of father–son transmissions. Overall, this work supports the use of genetic dating procedures that take into account the complexity of the phenomenon, with a repertoire of priors tailored on the particular dataset.     

Enhanced skeletal muscle arteriolar reactivity to ANG II after recovery from ischemic acute renal failure

In addition to the long-term renal complications, previous studies suggested that after acute renal failure (ARF), rats manifest an increased pressor response to an overnight infusion of ANG II. The present study tested whether recovery from ARF results in alterations in sensitivity to the peripheral vasculature. ARF was induced in Sprague-Dawley rats by 45 min of bilateral renal ischemia and reperfusion. Animals were allowed to recover renal structure and function for 5-8 wk, after which the acute pressor responses to ANG II were evaluated either in vivo in in situ skeletal muscle arterioles or in isolated gracilis muscle arteries in vitro. Baseline arterial pressure was not different in ARF rats vs. sham-operated controls, although ARF rats exhibited an enhanced pressor response to bolus ANG II infusion compared with control rats. Steady-state plasma ANG II concentration and plasma renin activity were similar between ARF and control rats. Constrictor reactivity of in situ cremasteric arterioles from ARF rats was enhanced in response to increasing concentrations of ANG II; however, no difference was observed in arteriolar responses to elevated PO2, norepinephrine, acetylcholine, or sodium nitroprusside. Isolated gracilis muscle arteries from ARF rats also showed increased vasoconstriction in response to ANG II but not norepinephrine. In conclusion, recovery from ischemic ARF is not associated with hypertension but is associated with increased arteriolar constrictor reactivity to ANG II. Although the mechanisms of this altered responsiveness are unclear, such changes may relate, in part, to cardiovascular complications in patients with ARF and/or after renal transplant.     

Specific peroxidase isoenzymes are correlated with organogenesis

We have examined isoperoxidase patterns obtained from buffer-, salt-, and enzyme-extractable fractions and correlated them with histological changes in tobacco (Nicotiana tabacum L., cv Wisc. 38) `epidermal' explants induced to produce either callus, vegetative buds, or floral buds. By utilizing a combination of extraction and electrophoretic procedures different from any hitherto used for this kind of investigation, we were able to resolve 47 isoperoxidases distributed between the three types of fractions. The majority of these isoperoxidases were common to all explants regardless of their developmental fate. Correspondingly, a number of histological changes were observed in all explants (e.g. the initiation of cell division by day 2, lignin deposition by day 4, and the formation of clustered tracheary elements by day 8). We have made correlations between 25 isoperoxidases and specific developmental events based on the time when certain isoperoxidases were detected relative to observed histological changes: 3 were correlated with desuppressed/sustained cell division, 3 to 6 with lignification/tracheary element maturation, 7 with callus formation, 1 with localized suppression of growth, 3 with determinate axial organization, 4 with leaf development, and 1 with stamen development. These results suggest that a continued investigation using this system could lead to a better understanding of the role of specific isoperoxidases in different developmental processes.