A randomized, double-blind study of zinpentraxin alfa in patients with myelofibrosis who were previously treated with or ineligible for ruxolitinib: Stage 2 of a phase II trial.

Not available.

An approach to develop personalized radiopharmaceuticals by modifying 2-[18F]fluoro-2-deoxy-D-glucose (2-[18F]FDG).

BACKGROUND: A challenge for modern medicine is the development of clinical protocols for precise diagnosis and therapy. This study aimed to propose a simple method for modification of 2-[18F]FDG used routinely in hospitals in a way, appropriate for patients' personalized radiopharmaceuticals approach. MATERIAL AND METHODS: For the purposes of the presented study chemo selective method for indirect radiofluorination was applauded to custom synthesized aminooxy- and hydrazine-functionalized tetrazines for 18F-glycolation via oxime or hydrazone formation. 2-[18F]FDG produced with medical baby cyclotron in Nuclear Medicine Clinic at the University Hospital St. Marina-Varna, was used. Thin layer chromatography (TLC) and radio TLC were used to follow the progress of synthesis and to determine radio chemical yield (RCY). RESULTS: The 2-[18F]FDG was modified with two bifunctional tetrazines aminooxy-acetic acid-6-(2-aminooxy-acetoxy)-[1,2,4,5] tetrazin-3-yl ester (Tz1) and {3-[4-(6-phenyl-[1,2,4,5]tetrazin-3-yl)-phenoxy]-propyl}-hydrazine (Tz2) via oxime and hydrazone formation. The radiolabeling was carried out as one-pot reaction with following parameters: temperature 70-75°C; catalyst p- diaminobenzene (Cat.); pH = 4.2; time 30 minutes; RCY = 70-99%. The radiolabeled tetrazines are appropriate for further bioorthogonal (pretargeting) strategy by click reactions with trans-cyclooctene conjugated bioactive molecules. The methodology is applicable to standard clinical conditions.

Safety and efficacy of zinpentraxin alfa as monotherapy or in combination with ruxolitinib in myelofibrosis: stage I of a phase II trial.

Pentraxin 2 (PTX-2; serum amyloid P component), a circulating endogenous regulator of the inflammatory response to tissue injury and fibrosis, is reduced in patients with myelofibrosis (MF). Zinpentraxin alfa (RO7490677, PRM-151) is a recombinant form of PTX-2 that has shown preclinical antifibrotic activity and no dose-limiting toxicities in phase I trials. We report results from stage 1 of a phase II trial of zinpentraxin alfa in patients with intermediate-1/2 or high-risk MF. Patients (n=27) received intravenous zinpentraxin α weekly (QW) or every 4 weeks (Q4W), as monotherapy or an additional therapy for patients on stable-dose ruxolitinib. The primary endpoint was overall response rate (ORR; investigatorassessed) adapted from International Working Group-Myeloproliferative Neoplasms Research and Treatment criteria. Secondary endpoints included modified Myeloproliferative Neoplasm-Symptom Assessment Form Total Symptom Score (MPN-SAF TSS) change, bone marrow (BM) MF grade reduction, pharmacokinetics, and safety. ORR at week 24 was 33% (n=9/27) and varied across individual cohorts (QW: 38% [3/8]; Q4W: 14% [1/7]; QW+ruxolitinib: 33% [2/6]; Q4W+ruxolitinib: 50% [3/6]). Five of 18 evaluable patients (28%) experienced a ≥50% reduction in MPN-SAF TSS, and six of 17 evaluable patients (35%) had a ≥1 grade improvement from baseline in BM fibrosis at week 24. Most treatment-emergent adverse events (AE) were grade 1-2, most commonly fatigue. Among others, anemia and thrombocytopenia were infrequent (n=3 and n=1, respectively). Treatment-related serious AE occurred in four patients (15%). Overall, zinpentraxin alfa showed evidence of clinical activity and tolerable safety as monotherapy and in combination with ruxolitinib in this open-label, non-randomized trial (clinicaltrials gov. Identifier: NCT01981850).

CaV2.1 channel mutations causing familial hemiplegic migraine type 1 increase the susceptibility for cortical spreading depolarizations and seizures and worsen outcome after experimental traumatic brain injury.

Patients suffering from familial hemiplegic migraine type 1 (FHM1) may have a disproportionally severe outcome after head trauma, but the underlying mechanisms are unclear. Hence, we subjected knock-in mice carrying the severer S218L or milder R192Q FHM1 gain-of-function missense mutation in the CACNA1A gene that encodes the α1A subunit of neuronal voltage-gated CaV2.1 (P/Q-type) calcium channels and their wild-type (WT) littermates to experimental traumatic brain injury (TBI) by controlled cortical impact and investigated cortical spreading depolarizations (CSDs), lesion volume, brain edema formation, and functional outcome. After TBI, all mutant mice displayed considerably more CSDs and seizures than WT mice, while S218L mutant mice had a substantially higher mortality. Brain edema formation and the resulting increase in intracranial pressure were more pronounced in mutant mice, while only S218L mutant mice had larger lesion volumes and worse functional outcome. Here, we show that gain of CaV2.1 channel function worsens histopathological and functional outcome after TBI in mice. This phenotype was associated with a higher number of CSDs, increased seizure activity, and more pronounced brain edema formation. Hence, our results suggest increased susceptibility for CSDs and seizures as potential mechanisms for bad outcome after TBI in FHM1 mutation carriers.

Sediment Assessment of the Pchelina Reservoir, Bulgaria.

The temporal dynamics of anthropogenic impacts on the Pchelina Reservoir is assessed based on chemical element analysis of three sediment cores at a depth of about 100-130 cm below the surface water. The 137Cs activity is measured to identify the layers corresponding to the 1986 Chernobyl accident. The obtained dating of sediment cores gives an average sedimentation rate of 0.44 cm/year in the Pchelina Reservoir. The elements' depth profiles (Ti, Mn, Fe, Zn, Cr, Ni, Cu, Mo, Sn, Sb, Pb, Co, Cd, Ce, Tl, Bi, Gd, La, Th and Unat) outline the Struma River as the main anthropogenic source for Pchelina Reservoir sediments. The principal component analysis reveals two groups of chemical elements connected with the anthropogenic impacts. The first group of chemical elements (Mn, Fe, Cr, Ni, Cu, Mo, Sn, Sb and Co) has increasing time trends in the Struma sediment core and no trend or decreasing ones at the Pchelina sampling core. The behavior of these elements is determined by the change of the profile of the industry in the Pernik town during the 1990s. The second group of elements (Zn, Pb, Cd, Bi and Unat) has increasing time trends in Struma and Pchelina sediment cores. The increased concentrations of these elements during the whole investigated period have led to moderate enrichments for Pb and Unat, and significant enrichments for Zn and Cd at the Pchelina sampling site. The moderately contaminated, according to the geoaccumulation indexes, Pchelina Reservoir surface sediment samples have low ecotoxicity.

Recycling of 18O enriched water used in 18F cyclotron production.

A simple, effective, easy-handling and reliable method for recycling of [18O]H2O from fluorine-18 production, was developed based on co-precipitation, co-crystallization and distillation. Preliminary experiments with normal H2O were used to determine the optimal purification conditions, which were tested for purification of used [18O]H2O from a scientific and commercial 18F-production facility. The obtained recycled [18O]H2O had comparable quality to commercially available 18O enriched water. The loss of weight for enriched water was about only 7% and losses of 18O enrichment about 1.3% ±â€¯0.2%. The method ensures elimination of radioisotopes (99.7% ±â€¯0.1%), organic compounds (99.5% ±â€¯0.1%) and trace metals (99.8% ±â€¯0.1%) with special attention on radiation safety with dosimetry control checks and in total 1000 times mass reduction of the initial radioactive waste.

Copper radiopharmaceuticals for theranostic applications.

The growing advancement in nuclear medicine challenges researchers from several different fields to integrate imaging and therapeutic modalities in a theranostic radiopharmaceutical, which can be defined as a molecular entity with readily replaceable radioisotope to provide easy switch between diagnostic and therapeutic applications for efficient and patient-friendly treatment of diseases. For such a reason, the diagnostic and therapeutic potential of all five medical radionuclides of copper have thoroughly been investigated as they boost the hope for development of successful radiotheranostics. To facilitate the mutual understanding between all different specialists working on this multidisciplinary field, we summarized the recent updates in copper-based nuclear medicine, with specific attention to the potential theranostic applications. Thereby, this review paper is focused on the current achievements in the copper-related complementary fields, such as synthetic and nuclear chemistry, biological assessment of radiopharmaceuticals, design and development of nanomaterials for multimodal theranostic implications. This work includes: i) description of available copper radionuclide production methods; ii) analyses of the synthetic strategies for development of improved copper radiopharmaceuticals; iii) summary of reported clinical data and recent preclinical studies from the last five years on biological applicability of copper radiopharmaceuticals; and iv) illustration of some sophisticated multimodal nanotheranostic agents that comprise several imaging and therapeutic modalities. Significant advancement can be seen in the synthetic procedures, which enables the broader implication of pretargeting approaches via bioorthogonal click reactions, as well as in the nanotechnology methods for biomimetic construction of biocompatible multimodal copper theranostics. All this gives the hope that personalized treatment of various diseases can be achieved by copper theranostics in the near future.

Synthesis and biological evaluation of novel (123)I-labeled 4-(4-iodophenyl)butanoyl-L-prolyl-(2S)-pyrrolidines for imaging prolyl oligopeptidase in vivo.

Prolyl oligopeptidase (POP) may be associated with neuromodulation and development of neurodegenerative diseases and it was recently shown to participate in the inflammatory cascade along with matrix metalloproteinases. Radiotracers, which can be used for non-invasive imaging, are needed for investigating the role of POP in normal physiology and in pathophysiological conditions in vivo. We synthesized two novel POP-specific (123)I-radiolabeled 4-phenylbutanoyl-L-prolyl-pyrrolidines of which 4-(4-[(123)I]iodophenyl)butanoyl-L-prolyl-2(S)-cyanopyrrolidine ([(123)I]2f, Ki = 4.2 nM) was selected. The selected compound has an electrophilic cyano group that is known to increase the dissociation time of POP inhibitors. [(123)I]2f was synthesized in high radiochemical yield and purity (87 ± 4%, >99%, respectively) and with a specific activity of 456 ± 98 GBq/µmol. [(123)I]2f was evaluated in healthy mice (C57Bl/6JRccHsd) by ex vivo biodistribution studies and SPECT imaging. Pretreatment with the known inhibitor 4-phenylbutanoyl-L-prolyl-(2S)-cyanopyrrolidine (KYP-2047, 2d, Ki = 0.023 nM) showed that binding of [(123)I]2f was POP specific. In addition, [(123)I]2f was evaluated in models of neuroinflammation and acute localized inflammation. A minor increase in binding of [(123)I]2f was observed in the inflamed region in the acute localized inflammation model. Similar increase in binding was not observed in the neuroinflammation model.

RNA expression profiling in brains of familial hemiplegic migraine type 1 knock-in mice.

BACKGROUND: Various CACNA1A missense mutations cause familial hemiplegic migraine type 1 (FHM1), a rare monogenic subtype of migraine with aura. FHM1 mutation R192Q is associated with pure hemiplegic migraine, whereas the S218L mutation causes hemiplegic migraine, cerebellar ataxia, seizures, and mild head trauma-induced brain edema. Transgenic knock-in (KI) migraine mouse models were generated that carried either the FHM1 R192Q or the S218L mutation and were shown to exhibit increased CaV2.1 channel activity. Here we investigated their cerebellar and caudal cortical transcriptome. METHODS: Caudal cortical and cerebellar RNA expression profiles from mutant and wild-type mice were studied using microarrays. Respective brain regions were selected based on their relevance to migraine aura and ataxia. Relevant expression changes were further investigated at RNA and protein level by quantitative polymerase chain reaction (qPCR) and/or immunohistochemistry, respectively. RESULTS: Expression differences in the cerebellum were most pronounced in S218L mice. Particularly, tyrosine hydroxylase, a marker of delayed cerebellar maturation, appeared strongly upregulated in S218L cerebella. In contrast, only minimal expression differences were observed in the caudal cortex of either mutant mice strain. CONCLUSION: Despite pronounced consequences of migraine gene mutations at the neurobiological level, changes in cortical RNA expression in FHM1 migraine mice compared to wild-type are modest. In contrast, pronounced RNA expression changes are seen in the cerebellum of S218L mice and may explain their cerebellar ataxia phenotype.

Silencing the majority of cerebellar granule cells uncovers their essential role in motor learning and consolidation.

Cerebellar granule cells (GCs) account for more than half of all neurons in the CNS of vertebrates. Theoretical work has suggested that the abundance of GCs is advantageous for sparse coding during memory formation. Here, we minimized the output of the majority of GCs by selectively eliminating their CaV2.1 (P/Q-type) Ca(2+) channels, which mediate the bulk of their neurotransmitter release. This resulted in reduced GC output to Purkinje cells (PCs) and stellate cells (SCs) as well as in impaired long-term plasticity at GC-PC synapses. As a consequence modulation amplitude and regularity of simple spike (SS) output were affected. Surprisingly, the overall motor performance was intact, whereas demanding motor learning and memory consolidation tasks were compromised. Our findings indicate that a minority of functionally intact GCs is sufficient for the maintenance of basic motor performance, whereas acquisition and stabilization of sophisticated memories require higher numbers of normal GCs controlling PC firing.

Cerebellar ataxia by enhanced Ca(V)2.1 currents is alleviated by Ca2+-dependent K+-channel activators in Cacna1a(S218L) mutant mice.

Mutations in the CACNA1A gene are associated with neurological disorders, such as ataxia, hemiplegic migraine, and epilepsy. These mutations affect the pore-forming α(1A)-subunit of Ca(V)2.1 channels and thereby either decrease or increase neuronal Ca(2+) influx. A decreased Ca(V)2.1-mediated Ca(2+) influx has been shown to reduce the regularity of cerebellar Purkinje cell activity and to induce episodic cerebellar ataxia. However, little is known about how ataxia can be caused by CACNA1A mutations that increase the Ca(2+) influx, such as the S218L missense mutation. Here, we demonstrate that the S218L mutation causes a negative shift of voltage dependence of Ca(V)2.1 channels of mouse Purkinje cells and results in lowered thresholds for somatic action potentials and dendritic Ca(2+) spikes and in disrupted firing patterns. The hyperexcitability of Cacna1a(S218L) Purkinje cells was counteracted by application of the activators of Ca(2+)-dependent K(+) channels, 1-EBIO and chlorzoxazone (CHZ). Moreover, 1-EBIO also alleviated the irregularity of Purkinje cell firing both in vitro and in vivo, while CHZ improved the irregularity of Purkinje cell firing in vitro as well as the motor performance of Cacna1a(S218L) mutant mice. The current data suggest that abnormalities in Purkinje cell firing contributes to cerebellar ataxia induced by the S218L mutation and they advocate a general therapeutic approach in that targeting Ca(2+)-dependent K(+) channels may be beneficial for treating ataxia not only in patients suffering from a decreased Ca(2+) influx, but also in those suffering from an increased Ca(2+) influx in their Purkinje cells.

Purkinje cell-specific ablation of Cav2.1 channels is sufficient to cause cerebellar ataxia in mice.

The Cacna1a gene encodes the α(1A) subunit of voltage-gated Ca(V)2.1 Ca(2+) channels that are involved in neurotransmission at central synapses. Ca(V)2.1-α(1)-knockout (α1KO) mice, which lack Ca(V)2.1 channels in all neurons, have a very severe phenotype of cerebellar ataxia and dystonia, and usually die around postnatal day 20. This early lethality, combined with the wide expression of Ca(V)2.1 channels throughout the cerebellar cortex and nuclei, prohibited determination of the contribution of particular cerebellar cell types to the development of the severe neurobiological phenotype in Cacna1a mutant mice. Here, we crossed conditional Cacna1a mice with transgenic mice expressing Cre recombinase, driven by the Purkinje cell-specific Pcp2 promoter, to specifically ablate the Ca(V)2.1-α(1A) subunit and thereby Ca(V)2.1 channels in Purkinje cells. Purkinje cell Ca(V)2.1-α(1A)-knockout (PCα1KO) mice aged without difficulties, rescuing the lethal phenotype seen in α1KO mice. PCα1KO mice exhibited cerebellar ataxia starting around P12, much earlier than the first signs of progressive Purkinje cell loss, which appears in these mice between P30 and P45. Secondary cell loss was observed in the granular and molecular layers of the cerebellum and the volume of all individual cerebellar nuclei was reduced. In this mouse model with a cell type-specific ablation of Ca(V)2.1 channels, we show that ablation of Ca(V)2.1 channels restricted to Purkinje cells is sufficient to cause cerebellar ataxia. We demonstrate that spatial ablation of Ca(V)2.1 channels may help in unraveling mechanisms of human disease.

Neuromuscular synaptic transmission in aged ganglioside-deficient mice.

Gangliosides are sialylated glycosphingolipids that are present in high density on neuronal membranes, especially at synapses, where they are assumed to play functional or modulating roles. Mice lacking GM2/GD2-synthase express only the simple gangliosides GD3 and GM3 and develop progressive motor behaviour deficits upon ageing, apparently due to failing complex ganglioside-dependent maintenance and/or repair processes or, alternatively, toxic GM3/GD3 accumulation. We investigated the function of neuromuscular junctions (NMJs) of aged (>9 month-old) GM2/GD2-synthase null-mutant mice, because synaptic dysfunction might develop with age and could potentially contribute to the late-onset motor phenotype. In addition, we studied NMJs of old mice lacking GD3-synthase (expressing only O- and a-series gangliosides), which do not show an overt neurological phenotype but may develop subclinical synaptic deficits. Detailed electrophysiological analyses showed subtle changes in presynaptic neurotransmitter release. Acetylcholine release at 40 Hz nerve stimulation at aged GM2/GD2-synthase null-mutant NMJs ran down slightly more pronounced than at wild-type NMJs, and spontaneous acetylcholine release rate at GD3-synthase null-mutant NMJs was somewhat higher than at wild-type, selectively at 25 °C bath temperature. Interestingly, we observed faster kinetics of postsynaptic electrophysiological responses at aged GD3-synthase null-mutant NMJs, not previously seen by us at NMJs of young GD3-synthase null-mutants or other types of (aged or young) ganglioside-deficient mice. These kinetic changes might reflect a change in postsynaptic acetylcholine receptor behaviour. Our data indicate that it is highly unlikely that transmission failure at NMJs contributes to the progressive motor defects of aged GM2/GD2-synthase null-mutants and that, despite some kinetic changes of synaptic signals, neuromuscular transmission remains successful in aged GD3-synthase null-mutant mice. Apparently, mutual redundancy of the different gangliosides in supporting presynaptic function, as observed previously by us in young mice, remains adequate upon ageing or, alternatively, gangliosides have only relatively little direct impact on neuromuscular synaptic function, even in aged mice.

High cortical spreading depression susceptibility and migraine-associated symptoms in Ca(v)2.1 S218L mice.

OBJECTIVE: The CACNA1A gene encodes the pore-forming subunit of neuronal Ca(V)2.1 Ca2+ channels. In patients, the S218L CACNA1A mutation causes a dramatic hemiplegic migraine syndrome that is associated with ataxia, seizures, and severe, sometimes fatal, brain edema often triggered by only a mild head trauma. METHODS: We introduced the S218L mutation into the mouse Cacna1a gene and studied the mechanisms for the S218L syndrome by analyzing the phenotypic, molecular, and electrophysiological consequences. RESULTS: Cacna1a(S218L) mice faithfully mimic the associated clinical features of the human S218L syndrome. S218L neurons exhibit a gene dosage-dependent negative shift in voltage dependence of Ca(V)2.1 channel activation, resulting in enhanced neurotransmitter release at the neuromuscular junction. Cacna1a(S218L) mice also display an exquisite sensitivity to cortical spreading depression (CSD), with a vastly reduced triggering threshold, an increased propagation velocity, and frequently multiple CSD events after a single stimulus. In contrast, mice bearing the R192Q CACNA1A mutation, which in humans causes a milder form of hemiplegic migraine, typically exhibit only a single CSD event after one triggering stimulus. INTERPRETATION: The particularly low CSD threshold and the strong tendency to respond with multiple CSD events make the S218L cortex highly vulnerable to weak stimuli and may provide a mechanistic basis for the dramatic phenotype seen in S218L mice and patients. Thus, the S218L mouse model may prove a valuable tool to further elucidate mechanisms underlying migraine, seizures, ataxia, and trauma-triggered cerebral edema.

Total ganglioside ablation at mouse motor nerve terminals alters neurotransmitter release level.

Neuronal membrane gangliosides, forming a large family of sialylated glycosphingolipids, have been hypothesized to play important roles in synaptic transmission. We studied the ex vivo electrophysiological function of neuromuscular junctions of GM2/GD2-synthase*GD3-synthase compound null-mutant mice after acute removal of GM3, the only remaining ganglioside in this mouse, by in vitro treatment with neuraminidase. We found 16% enhancement of the acetylcholine release per nerve impulse at low-rate (0.3 Hz) nerve stimulation. Conversely, the treatment reduced the acetylcholine release evoked by high-rate (40 Hz) nerve stimulation. Also, 25 ms paired-pulse facilitation of endplate potentials was reduced by the neuraminidase-treatment. These effects may indicate a modest modulatory influence of the negative electrical charges carried by the sialic acid molecules of gangliosides on the function of presynaptic Ca(v)2.1 channels, affecting the magnitude and kinetics of the Ca(2+) influx that induces neurotransmitter release from the motor nerve terminal. Our results show that gangliosides are to some extent involved in neurotransmission at the neuromuscular junction, but that their presence is not an absolute requirement in this process.

Redundancy of Cav2.1 channel accessory subunits in transmitter release at the mouse neuromuscular junction.

Ca(v)2.1 (P/Q-type) channels possess a voltage-sensitive pore-forming alpha(1) subunit that can associate with the accessory subunits alpha(2)delta, beta and gamma. The primary role of Ca(v)2.1 channels is to mediate transmitter release from nerve terminals both in the central and peripheral nervous system. Whole-cell voltage-clamp studies in in vitro expression systems have indicated that accessory channel subunits can have diverse modulatory effects on membrane expression and biophysical properties of Ca(v)2.1 channels. However, there is only limited knowledge on whether similar modulation also occurs in the specific presynaptic environment in vivo and, hence, whether accessory subunits influence neurotransmitter release. Ducky, lethargic and stargazer are mutant mice that lack functional alpha(2)delta-2, beta(4) and gamma(2) accessory Ca(v) channel subunits, respectively. The neuromuscular junction (NMJ) is a peripheral synapse, where transmitter release is governed exclusively by Ca(v)2.1 channels, and which can be characterized electrophysiologically with relative experimental ease. In order to investigate a possible synaptic influence of accessory subunits in detail, we electrophysiologically measured acetylcholine (ACh) release at NMJs of these three mutants. Surprisingly, we did not find any changes compared to wild-type littermates, other than a small reduction (25%) of evoked ACh release at ducky NMJs. This effect is most likely due to the approximately 40% reduced synapse size, associated with the reduced size of ducky mice, rather than resulting directly from reduced Ca(v)2.1 channel function due to alpha(2)delta-2 absence. We conclude that alpha(2)delta-2, beta(4), and gamma(2) accessory subunits are redundant for the transmitter release-mediating function of presynaptic Ca(v)2.1 channels at the mouse NMJ.

Conditional inactivation of the Cacna1a gene in transgenic mice.

Ca(v)2.1 (P/Q-type) voltage-gated calcium channels play an important role in neurotransmitter release at many brain synapses and at the neuromuscular junction. Mutations in the CACNA1A gene, encoding the pore forming alpha(1) subunit of Ca(v)2.1 channels, are associated with a wide spectrum of neurological disorders. Here we generated mice with a conditional, floxed, Cacna1a allele without any overt phenotype. Deletion of the floxed Cacna1a allele resulted in ataxia, dystonia, and lethality during the fourth week, a severe phenotype similar to conventional Ca(v)2.1 knockout mice. Although neurotransmitter release at the neuromuscular junction was not affected in the conditional mice, homozygous deletion of the floxed allele caused an ablation of Ca(v)2.1 channel-mediated neurotransmission that was accompanied by a compensatory upregulation of Ca(v)2.3 (R-type) channels at this synapse. Pharmacological inhibition of Ca(v)2.1 channels is possible, but the contributing cell-types and time windows relevant to the different Ca(v)2.1-related neurological disorders can only be reliably determined using Cacna1a conditional mice.