Comparative Study of Laser- attenuated and Gamma attenuated irradiated larval Vaccines of Dictyocaulus filaria in goats.

A comparative trial between the effect of 3rd stage Dictyocaulus filaria larval vaccine attenuated by continuous emission of visible Helium – Neon Laser of ImW and wave length of ( 632.8 ) nm of (5) minutes exposure that of gamma attenuated larvae at 0.5 k. gray ( Co as radiation Source ) was designed. Each of the two attenuated larval vaccines was given to a group of ( 5 ) kids each . Double immunization doses at ( 35 ) days interval from each vaccine were given orally. The first dose contained ( 1000 ) larvae and the second one ( 2000 ) for each . A challenge dose of ( 100 ) non- irradiated larvae /kg body weight was given after ( 5 ) week to the vaccinated groups and a control non- vaccinated (5 kids ) 3rd group. All animals were slaughtered after 6 weeks post challenge. Results showed that both vaccines revealed 80.7% and 78.1% protection respectively for worm burden as compared to control. Laser attenuated vaccine exhibited a statistically significant inhibition in the fecundity of female worms and larvae secretion in faeces in comparison with the gamma irradiated vaccine.

Tolerance to neurochemical and behavioral effects of the hallucinogen 25I-NBOMe

Rationale 4-Iodo-2,5-dimethoxy-N-(2-methoxybenzyl)phenethylamine (25I-NBOMe) is a potent serotonin 5-HT2A/2C receptor agonist with hallucinogenic activity. There is no data on the 25I-NBOMe effect on brain neurotransmission and animal performance after chronic administration. Objectives We examined the effect of a 7-day treatment with 25I-NBOMe (0.3 mg/kg/day) on neurotransmitters’ release and rats’ behavior in comparison to acute dose. Methods Changes in dopamine (DA), serotonin (5-HT), acetylcholine (ACh), and glutamate release were studied using microdialysis in freely moving rats. The hallucinogenic activity was measured in the wet dog shake (WDS) test. The animal locomotion was examined in the open field (OF) test, short-term memory in the novel object recognition (NOR) test. The anxiogenic/anxiolytic properties of the drug were tested using the light/dark box (LDB) test. Results Repeated administration of 25I-NBOMe decreased the response to a challenge dose of DA, 5-HT, and glutamatergic neurons in the frontal cortex as well as weakened the hallucinogenic activity in comparison to acute dose. In contrast, striatal and accumbal DA and 5-HT release and accumbal but not striatal glutamate release in response to the challenge dose of 25I-NBOMe was increased in comparison to acute treatment. The ACh release was increased in all brain regions. Behavioral tests showed a motor activity reduction and memory deficiency in comparison to a single dose and induction of anxiety after the drug’s chronic and acute administration. Conclusions Our findings suggest that multiple injections of 25I-NBOMe induce tolerance to hallucinogenic activity and produce alterations in neurotransmission. 25I-NBOMe effect on short-term memory, locomotor function, and anxiety seems to be the result of complex interactions between neurotransmitter pathways.

Viral dosing of influenza A infection reveals involvement of RIPK3 and FADD, but not MLKL

RIPK3 was reported to play an important role in the protection against influenza A virus (IAV) in vivo. Here we show that the requirement of RIPK3 for protection against IAV infection in vivo is only apparent within a limited dose range of IAV challenge. We found that this protective outcome is independent from RIPK3 kinase activity and from MLKL. This shows that platform function of RIPK3 rather than its kinase activity is required for protection, suggesting that a RIPK3 function independent of necroptosis is implicated. In line with this finding, we show that FADD-dependent apoptosis has a crucial additional effect in protection against IAV infection. Altogether, we show that RIPK3 contributes to protection against IAV in a narrow challenge dose range by a mechanism that is independent of its kinase activity and its capacity to induce necroptosis.

Pegaspargase Re-Challenge after Grade 2 Hypersensitivity Reaction in Childhood Acute Lymphoblastic Leukemia: Results from DFCI 16-001

Introduction: Hypersensitivity reactions with asparaginase occur frequently in pediatric patients (pts) with acute lymphoblastic leukemia (ALL). The standard approach for pts with reaction to E.coli-derived asparaginase is to switch to Erwinia asparaginase, given concern that clinical reactions reflect presence of neutralizing antibodies; however, Erwinia requires more frequent dosing and is often unavailable. Therapeutic drug monitoring allows for discrimination between pts with pegaspargase hypersensitivity who have sub-therapeutic asparaginase activity and those still able to derive therapeutic benefit from pegaspargase. We prospectively piloted re-challenging pts with pegaspargase after initial Grade 2 hypersensitivity to this agent, with premedication at re-challenge and assessment of serum asparaginase activity (SAA). Methods: Pts aged 1 to < 22 years with newly diagnosed ALL were eligible for DFCI 16-001. Pts received 1 dose of intravenous pegaspargase during Induction, and every 2 weeks for 15 total doses in Post-Induction phases, without routine premedication. Pts were monitored during/after pegaspargase for allergy, with CTCAE version 4.0 event grading. Those with ≥Grade 3 allergy discontinued pegaspargase and were switched to Erwinia. Those with Grade 2 allergic reaction were eligible for pegaspargase re-challenge with pre-medication (acetaminophen, diphenhydramine, and hydrocortisone, or per institutional standard) and slower infusion rate. If < 50% of the intended dose had been administered when reaction occurred, re-challenge was within 1-7 days of initial reaction. If ≥ 50% of the intended dose had been given, re-challenge was at next planned pegaspargase dose. SAA was measured 1-hour, 7-days, and 14-days after the re-challenge infusion (if dose completed). If 1-hour or 7-day level ≥ 0.1 IU/mL, and 14-day level ≥ 0.025 IU/mL, SAA was considered adequate, and the pt continued to receive pegaspargase with premedication. Pts with an inadequate SAA level, or with new ≥ Grade 2 allergic reaction with the re-challenge dose were considered to have failed re-challenge and were changed to Erwinia (or enrolled on a clinical trial of recombinant crisantaspase, an alternative Erwinia preparation). Results: Between 3/2017- 7/2020, 317 eligible pts enrolled. Overall, 81 of 299 (27%) total evaluable pts experienced a first allergic reaction to pegaspargase, 68 pts with Grade 2 reaction, 13 with Grade ≥3. During Induction, 17 of 299 (6%) evaluable pts had allergic reaction to pegaspargase; all Grade 2. Of the 17 Grade 2 reactions, 13 pts (76%) underwent re-challenge in Induction, 9 (69%) re-challenges successful and 4 failed. Post-Induction, 64 of 241 evaluable pts (27%) had a first allergic reaction; 51 Grade 2 and 13 Grade ≥3. Thirty-six of 51 (71%) pts with Grade 2 allergy during Post-Induction underwent re-challenge, as did 1 additional pt with allergy during Induction who was re-challenged with first Post-Induction pegaspargase dose (per protocol guideline, due to receiving ≥50% of Induction dose). Among these re-challenges, 16 were successful, 21 failed. Overall, 25 of 50 (50%) pts who were re-challenged after Grade 2 reaction had a successful challenge and were able to continue pegaspargase. Among the 25 pts with failed re-challenge, 6 pts (24%) had inadequate SAA alone as cause of failure, 17 pts (68%) had an allergic reaction with the re-challenge dose, and 2 (8%) additional patients had both allergic reaction and documented inadequate SAA. Three pts who were successfully re-challenged had a subsequent allergic reaction to pegaspargase. Among the 22 pts who experienced another allergic reaction with pegaspargase (at re-challenge or subsequent dose), 19 pts (86%) experienced Grade 2, and 3 pts experienced Grade 3 reaction. Conclusion: Fifty percent of pts with a Grade 2 reaction to pegaspargase were able to tolerate and achieve adequate SAA when re-challenged with premedication. For those who did react with or after re-challenge, reactions were not more severe. The re-challenge approach limits premedication exposure only to a minority of pts with a history of prior reaction and substantially decreases the number of pts needing to switch to Erwinia asparaginase, which can be challenging to deliver due to administration schedule and drug shortage. Disclosures Place: Novartis: Consultancy, Other: Institutional Research Funding; AbbVie: Consultancy. Silverman:Takeda: Other: advisory board; Servier: Other: advisory board; Syndax: Other: advisory board.

Evaluation of Glycosylated FlpA and SodB as Subunit Vaccines Against Campylobacter jejuni Colonisation in Chickens

Campylobacter jejuni is the leading bacterial cause of human gastroenteritis worldwide and the handling or consumption of contaminated poultry meat is the key source of infection. C. jejuni proteins FlpA and SodB and glycoconjugates containing the C. jejuni N-glycan have been separately reported to be partially protective vaccines in chickens. In this study, two novel glycoproteins generated by protein glycan coupling technology—G-FlpA and G-SodB (with two and three N-glycosylation sites, respectively)—were evaluated for efficacy against intestinal colonisation of chickens by C. jejuni strain M1 relative to their unglycosylated variants. Two independent trials of the same design were performed with either a high challenge dose of 107 colony-forming units (CFU) or a minimum challenge dose of 102 CFU of C. jejuni M1. While antigen-specific serum IgY was detected in both trials, no reduction in caecal colonisation by C. jejuni M1 was observed and glycosylation of vaccine antigens had no effect on the outcome. Our data highlight inconsistencies in the outcome of C. jejuni vaccination trials that may reflect antigen-, challenge strain-, vaccine administration-, adjuvant- and chicken line-specific differences from previously published studies. Refinement of glycoconjugate vaccines by increasing glycosylation levels or using highly immunogenic protein carriers could improve their efficacy.

Experimental Infection of Dogs with Toscana Virus and Sandfly Fever Sicilian Virus to Determine Their Potential as Possible Vertebrate Hosts

The sandfly-borne Toscana phlebovirus (TOSV), a close relative of the sandfly fever Sicilian phlebovirus (SFSV), is one of the most common causes of acute meningitis or meningoencephalitis in humans in the Mediterranean Basin. However, most of human phlebovirus infections in endemic areas either are asymptomatic or cause mild influenza-like illness. To date, a vertebrate reservoir for sandfly-borne phleboviruses has not been identified. Dogs are a prime target for blood-feeding phlebotomines and are the primary reservoir of human sandfly-borne Leishmania infantum. However, there are no definitive studies to assess whether dogs play a significant role as a reservoir host for human phlebovirus survival in the environment. Here, we have evaluated the susceptibility of domestic dogs to infection by TOSV and SFSV following the direct inoculation of the infectious virus. After experimental infection, the presence of viral RNA was investigated in plasma, urine, saliva, conjunctiva, faeces, semen, and bone marrow samples from 0 to 91 days postinoculation (dpi), as well as in plasma, saliva, and tears samples at 760 dpi. None of the challenged dogs developed clinical signs of infection with either TOSV or SFSV. SFSV RNA was never detected. TOSV RNA was not in any of the specimen types, except for plasma samples that showed low viral loads, although irregularly. None of the dogs developed detectable neutralizing antibodies after a single challenge dose of either TOSV or SFSV. However, a second challenge dose of virus given 56 days later elicited neutralizing antibodies, implying that the first inoculation of virus primed the animals for an anamnestic response following the second challenge. These results demonstrated that healthy domestic dogs are not highly susceptible to infection by TOSV or SFSV and do not develop significant viremia or excrete virus following infection. Consequently, dogs are unlikely natural reservoir hosts of infection and do not appear to play a significant role in phlebovirus transmission cycles.

Isoliquiritigenin Attenuates Anxiety-Like Behavior and Locomotor Sensitization in Rats after Repeated Exposure to Nicotine

As important components of positive and negative reinforcement, locomotor sensitization and withdrawal anxiety following repeated exposure to nicotine (NIC) constitute crucial risk factors for relapse to NIC use after abstinence. Glycyrrhiza radix (G. radix), an important tonic used in traditional Oriental medicine, has not only anxiolytic effects but also reduces NIC-induced locomotor sensitization. Isoliquiritigenin (ISL), a bioactive ingredient of G. radix, also exhibits neuropharmacological effects, including anxiolytic action. Previously, we reported that ISL suppressed cocaine-induced extracellular dopamine release in the nucleus accumbens shell (NaccSh) and attenuated methamphetamine-induced neurotoxicity. The present study was performed to evaluate the effects of ISL on both NIC withdrawal anxiety and locomotor sensitization. Adult male rats received subcutaneous administration of NIC hydrogen tartrate (0.4 mg/kg, twice a day) for 7 days followed by 4 days of withdrawal. During the period of NIC withdrawal, the rats received four intragastric treatments with ISL (3, 10, or 30 mg/kg/day). All three doses of ISL significantly inhibited NIC withdrawal-induced anxiety-like behaviors in the elevated plus maze (EPM) test, but only the 10 mg/kg/day and 30 mg/kg/day ISL doses attenuated locomotor sensitization induced by a challenge dose of NIC. Intracerebroventricular ISL also inhibited both NIC-induced withdrawal anxiety and locomotor sensitization, but intra-NaccSh injection of ISL blocked only NIC locomotor sensitization, which was abolished by post-ISL infusion of tert-butyl hydroperoxide (an oxidant) or N-methyl-D-aspartate (NMDA) into the NaccSh. Moreover, there was increased protein expression of phosphorylated Erk1/2 in the NIC-sensitized NaccSh, which was suppressed by ISL. Taken together, these results suggest that ISL can inhibit repeated NIC-induced withdrawal anxiety and locomotor sensitization, and the latter is mediated by antagonizing accumbal reactive oxygen species and NMDA receptor signaling.