Quantification and pharmacological characterization of dialysate levels of noradrenaline in the striatum of freely-moving rats: release from adrenergic terminals and modulation by α2-autoreceptors

Information concerning striatal levels of noradrenaline (NA) remains inconsistent. Here we have addressed this issue using a sensitive method of HPLC coupled to amperometric detection. The NA reuptake-inhibitor, reboxetine, selectively elevated levels of NA versus dopamine (DA), and NA levels were also selectively elevated by the α₂-adrenoceptor (AR) antagonist, atipamezole. The actions of atipamezole were mimicked by the preferential α_2A-AR antagonist, BRL44408, while JO-1 and prazosin, preferential antagonists at α_2C-ARs, caused less marked elevations in NA levels. In contrast to antagonists, the α₂-AR agonist, S18616, decreased NA levels and likewise suppressed those of DA. Unilateral lesions of the substantia nigra with 6-hydroxydopamine depleted DA levels without affecting those of NA. Further, the D₃/D₂ receptor agonist, quinelorane, decreased levels of DA without modifying those of NA. However, the D₃/D₂ receptor antagonists, haloperidol and raclopride, and the DA reuptake-inhibitor, GBR12935, elevated levels of both DA and NA. Levels of 5-HT (but not of NA or DA) were increased only by the 5-HT reuptake-inhibitor, citalopram. They were decreased by S18616 and prazosin, reflecting the inhibitory and excitatory influence of α₂- and α₁-ARs, respectively, upon serotonergic pathways. In conclusion, NA in the striatum is derived from adrenergic terminals. Its release is subject to tonic, inhibitory control by α₂-ARs, possibly involving both α_2A- and α_2C-AR subtypes, though their respective contribution requires clarification. A role of dopaminergic terminals in the reuptake of NA likely explains the elevation in its levels elicited by DA reuptake-inhibitors and D₃/D₂ receptor antagonists.     

Comparison of two target genes for detection and genotyping of Giardia lamblia in human feces by PCR and PCR-restriction fragment length polymorphism

A PCR assay targeting the tpi gene was developed to detect and to genotype Giardia lamblia in human feces. Our assay was specific and discriminated between G. lamblia assemblages A and B. G. lamblia cysts isolated from human feces were also analyzed with two previously described PCR-restriction fragment length polymorphism (RFLP) assays, which are based on the detection of tpi or gdh genes. These RFLP analyses distinguished groups I and II within assemblage A or groups III and IV within assemblage B. Among 26 fecal samples from patients with sporadic giardiasis diagnosed by hospital laboratories, the tpi gene was amplified from 25 (96%) with our PCR assay, whereas only 21 (81%) samples were positive when the gdh gene was targeted. Of the 25 positive samples, nine (36%) contained assemblage A and 16 (64%) contained assemblage B. Thus, RFLP analysis classified eight samples (32%) in assemblage A group II, eight (32%) in assemblage B group III, and five (20%) in assemblage B group IV. The group could not be specified for four samples. The tpi and gdh genes of G. lamblia assemblage B were amplified from 14 (93%) of 15 samples collected only from French soldiers coming back from the Ivory Coast. All of these contained assemblage B group III. The PCR method developed is sensitive, simple, and specific and shows that the tpi gene is well adapted for G. lamblia genotyping.     

Characterization of wild-type recombinant Bet v 1a as a candidate vaccine against birch pollen allergy

BACKGROUND: We describe the production in Escherichia coli as a recombinant protein of clinical grade wild-type Bet v 1a (rBet v 1a), to be used as a candidate vaccine against birch pollen allergy. METHODS: This recombinant protein was purified by hydrophobic interaction and ion exchange chromatography and characterized by SDS-PAGE, immunoprint and circular dichroism in parallel with natural Bet v 1 (nBet v 1) purified from a birch pollen extract. We also compared rBet v 1 and nBet v 1 for their capacity to induce histamine release from basophils and to stimulate T lymphocyte proliferation. RESULTS: rBet v 1a appears in SDS-PAGE as an 18-kDa monomeric protein, whereas purified nBet v 1 comprises a mixture of isoforms (resolving as three distinct bands and six spots after 1-dimensional and 2-dimensional electrophoresis, respectively). Both recombinant and natural purified Bet v 1 molecules are recognized by IgE from birch pollen-allergic patients as well as anti-Bet v 1 murine monoclonal antibodies, suggesting that the recombinant protein is correctly folded in a native configuration. Circular dichroism analysis confirmed that the two Bet v 1 molecules exhibit similar 3-dimensional structures, even if rBet v 1a appears more compact and stable in thermodenaturation/renaturation experiments. Both rBet v 1 and nBet v 1 induce the degranulation of sensitized basophils and proliferation of Bet v 1-specific T lymphocytes in a similar manner. CONCLUSIONS: On the basis of these structural and biological properties, rBet v 1a is a valid candidate vaccine against birch pollen allergy, currently evaluated in humans.     

Epicutaneous immunotherapy protects cashew-sensitized mice from anaphylaxis

Background

The prevalence of tree nut allergy has increased worldwide, and cashew has become one of the most common food allergens. More critically, cashew allergy is frequently associated with severe anaphylaxis. Despite the high medical need, no approved treatment is available and strict avoidance and preparedness for prompt treatment of allergic reactions are considered dual standard of care. In the meantime, Phase III study results suggest investigational epicutaneous immunotherapy (EPIT) may be a relevant and safe treatment for peanut allergy and may improve the quality of life for many peanut allergic children.

Objective

We aimed to evaluate the capacity of EPIT to provide protection against cashew-induced anaphylaxis in a relevant mouse model.

Methods

The efficacy of EPIT was evaluated by applying patches containing cashew allergens to cashew-sensitized mice. As negative control, sham mice received patches containing excipient. Following treatment, mice were challenged orally to cashew and anaphylactic symptoms, as well as plasmatic levels of mast-cell proteases (mMCP)-1/7, were quantified.

Results

Of 16 weeks of EPIT significantly protects against anaphylaxis by promoting a faster recovery of challenged mice. This protection was characterized by a significant reduction of temperature drop and clinical symptoms, 60 minutes after challenge. This was associated with a decrease in mast-cell reactivity as attested by the reduction of mMCP-1/7 in plasma, suggesting that EPIT specifically decrease IgE-mediated anaphylaxis.

Conclusion

We demonstrate that EPIT markedly reduced IgE-mediated allergic reactions in a mouse model of cashew allergy, which suggests that EPIT may be a relevant approach to treating cashew allergy.

     

High-Density SNP genotyping defines 17 distinct haplotypes of the TNF block in the Caucasian population: implications for haplotype tagging

The region spanning the tumor necrosis factor (TNF) cluster in the human major histocompatibility complex (MHC) has been implicated in susceptibility to numerous immunopathological diseases, including type 1 diabetes mellitus and rheumatoid arthritis. However, strong linkage disequilibrium across the MHC has hampered the identification of the precise genes involved. In addition, the observation of "blocks" of DNA in the MHC within which recombination is very rare, limits the resolution that may be obtained by genotyping individual SNPs. Hence a greater understanding of the haplotypes of the block spanning the TNF cluster is necessary. To this end, we genotyped 32 human leukocyte antigen (HLA)-homozygous workshop cell lines and 300 healthy control samples for 19 coding and promoter region SNPs spanning 45 kb in the central MHC near the TNF genes. The workshop cell lines defined 11 SNP haplotypes that account for approximately 80% of the haplotypes observed in the 300 control individuals. Using the control individuals, we defined a further six haplotypes that account for an additional 10% of donors. We show that the 17 haplotypes of the "TNF block" can be identified using 15 SNPs.     

Phase I Study of JNJ-74699157 in Patients with Advanced Solid Tumors Harboring the KRAS G12C Mutation

BackgroundPatients with KRAS-mutant cancers have limited treatment options. Here we present a phase I study of JNJ-74699157, an oral, selective, covalent inhibitor of the KRAS G12C isoform, in patients with advanced cancer harboring the KRAS G12C mutation.MethodsEligible patients (aged ≥18 years) who had previously received or were ineligible for standard treatment received JNJ-74699157 once daily on a 21-day cycle. Dose escalation was guided by a modified continual reassessment method.ResultsTen patients (100 mg: 9 and 200 mg: 1) were enrolled. Tumor types included non–small cell lung cancer (n = 5), colorectal cancer (n = 4), and carcinoma of unknown primary site (n = 1). The median age was 65 (range: 36-74) years and median treatment duration was 2.91 (range: 0.5-7.5) months. Dose-limiting toxicities of grades 3–4 increased blood creatinine phosphokinase (CPK) were observed in 100 mg and 200 mg dose levels. The most common adverse event was increased blood CPK (6 patients). No significant clinical benefit was observed; the best response was stable disease in 4 patients (40%).ConclusionBased on dose-limiting skeletal muscle toxicities and the lack of efficacy at the 100 mg dose, further enrollment was stopped. The safety profile of JNJ-74699157 was not considered favorable for further clinical development.ClinicalTrials.gov Identifier{"type":"clinical-trial","attrs":{"text":"NCT04006301","term_id":"NCT04006301"}}NCT04006301     

Impact of G-CSF Prophylaxis on Chemotherapy Dose-Intensity,Link Between Dose-Intensity and Survival in Patients with Metastatic Pancreatic Adenocarcinoma

BackgroundIn metastatic pancreatic adenocarcinoma, few data are available on the use of granulocyte-colony stimulating factor (G-CSF) prophylaxis and its impact on dose-intensity (DI), or the link between DI and progression-free survival (PFS). This study assessed the impact of G-CSF prophylaxis on the DI received by patients and the relationship between full DI and PFS according to chemotherapy regimens.Patients and MethodsPatients from three first-line randomized phase II clinical trials were included in this retrospective cohort. G-CSF prophylaxis groups were identified and balanced according to baseline characteristics using a propensity score. Patients were classified into 2 treatment groups (FOLFIRINOX vs FOLFIRI/nab-paclitaxel (NAB)). DI was a binary variable (full/reduced). Adverse events were defined using NCI-CTCAE v4.0.ResultsOf the 498 patients, 154 (31%) were in “prophylaxis” group; 179 (36%) were treated by FOLFIRINOX and 319 (64%) by FOLFIRI/NAB. In FOLFIRINOX group, G-CSF prophylaxis was significantly associated with a higher rate of full DI (OR, 5.07; 95% CI, 1.52-16.90; P < .01) while in FOLFIRI/NAB group, it was significantly associated with a lower rate of full DI (OR, 0.23; 95% CI, 0.06-0.83; P = .03). Full DI was associated with a non-significant increase in PFS (FOLFIRINOX group: HR 0.83; 95% CI, 0.59-1.16; P = .27; FOLFIRI/NAB group: HR 0.84; 95% CI, 0.63-1.11; P = .22).ConclusionGranulocyte-colony stimulating factor prophylaxis was associated with a higher rate of full DI with FOLFIRINOX. Full DI was associated with a non-significant increase in PFS. These results need to be confirmed prospectively.     

Enzymatically degraded Eurylon 6 HP-PG: ethylcellulose film coatings for colon targeting in inflammatory bowel disease patients

Objectives Film coatings based on blends of Eurylon 6 HP‐PG (a hydroxypropylated and pregelatinized high amylose starch) and ethylcellulose were to be evaluated as promising coating materials for site‐specific drug delivery to the colon of patients suffering from inflammatory bowel diseases. Methods Pellet starter cores containing 60% 5‐aminosalicylic acid were prepared by extrusion/spheronization and coated with different Eurylon 6 HP‐PG : ethylcellulose blends at various coating levels. Drug release was measured in media simulating the contents of the upper gastrointestinal tract (in the presence and absence of enzymes) as well as in media simulating the contents of the colon. Key findings 5‐Aminosalicylic acid release could effectively be suppressed in 0.1 N HCl and phosphate buffer pH 6.8, optionally containing pepsin or pancreatin, but occurred as soon as the pellets came into contact with culture medium inoculated with faecal samples from inflammatory bowel disease patients. This can be attributed to the partial degradation of the starch derivative by enzymes secreted by bacteria present in the colon of these patients. Conclusions The presented drug delivery system is adapted to the pathophysiological conditions in inflammatory bowel disease patients. Furthermore, drug release remained unaltered upon 1 year open storage.