Swiss Webster Mice Research Articles

Chronic escalating-dose and acute binge cocaine treatments change the hippocampal cholinergic muscarinic system on drug presence and after withdrawal

Cocaine addiction is a relapsing disorder with loss of control in limiting drug intake. Considering the involvement of acetylcholine in the neurobiology of the disease, our aim was to evaluate whether cocaine induces plastic changes in the hippocampal cholinergic muscarinic system. Male Swiss-Webster mice received saline or cocaine (ip) three times daily (60-min intervals) either acutely or in an escalating-dose binge paradigm for 14 days. Locomotor activity was measured in all treatment days. Dopaminergic and cholinergic muscarinic receptors (D1R, D2R, M1-M5, mAChRs), choline acetyltransferase (ChAT), vesicular acetylcholine transporter (VAChT) and acetylcholinesterase (AChE) were quantified in the hippocampus by immunoblotting one hour after the last injection (on drug) or after 14 days of abstinence (withdrawal). Escalating-dose group showed cocaine-induced locomotor sensitization from day 2. M3 mAChR and ChAT significantly increased after the on-drug acute binge treatment. Escalating-dose on-drug group showed increased ChAT, M1, M5 mAChR and D2R; and decreased D1R. Acute-binge withdrawal group showed increased VAChT, M2 mAChR, D1R, and D2R; and decreased M1 mAChR. Escalating-dose withdrawal group presented increased D1R and VAChT and decreased M1 mAChR and D2R. Locomotor activity was negatively correlated with M1 mAChR and AChE in on-drug group and positively correlated with VAChT in withdrawal group. M1 mAChR was positively correlated with M2 mAChR and ChAT in on-drug group, whereas ChAT was positively correlated with M5 mAChR in withdrawal group. The results indicate that cocaine induced an increase in the hippocampal cholinergic tone in the presence of the drug, whereas withdrawal causes a resetting in the system.

Robust efficacy and long-lasting humoral immunity induced by a respiratory syncytial virus prefusion F-based nanoparticle vaccine in genetically diverse animal models

Abstract Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infections in children, accounting for 7% of deaths in those less than one year of age. Despite multiple exposures to RSV throughout life, natural infection affords only partial protection and there is currently no licensed vaccine against RSV. We developed a vaccine candidate, RSVNanoVax, composed of polyanhydride nanoparticles encapsulating the RSV prefusion F protein and a CpG1668 adjuvant. To assess the efficacy of RSVNanoVax we utilized two model systems with increased genetic variability, Swiss Webster mice and the cotton rat. Following an intranasal prime-boost vaccination with RSVNanoVax, Swiss Webster mice exhibited robust titers of RSV F-directed IgG antibodies in both the serum and lung tissue that were sustained out to at least 1-year post-vaccination. RSV F-directed IgA was also induced within the lung tissue and nasal passages, suggesting that RSVNanoVax stimulates long-lasting systemic and mucosal antibody responses in outbred mice. Serum antibodies maintained robust neutralizing activity against both RSV A and B virus strains. Following RSV challenge, vaccinated mice exhibited complete viral clearance in the lungs as early as day 2 post-infection. Further studies performed in cotton rats demonstrated that RSVNanoVax conferred protection from both viral replication in the lungs as well as RSV-induced pulmonary immunopathology following viral challenge. Vaccinated cotton rats also exhibited robust titers of RSV F-directed serum antibodies with neutralizing capacity. Overall, RSVNanoVax represents a promising RSV vaccine candidate capable of providing long-term protection and immunity in genetically diverse populations. Supported by grants from NIH (R01 AI124093, T32 CA078586, T32 AI007485)

Hyperpolarization‐Activated Current Shows Excitatory Effect on Fictive Locomotion in the Neonatal Mouse Under Hyperdopaminergic Conditions

Restless Leg Syndrome (RLS) is a chronic sensorimotor disorder that has recently been linked to a downregulation in adenosine A1 receptors (A1R), leading to decreased formation of adenosine‐dopamine heteromers and a disinhibited or hyperdopaminergic transmission pathway within the central nervous system. Dopamine D1 receptor (D1R) activation has been shown to modulate HCN1 channels via its stimulatory effect on cAMP production to increase the hyperpolarization‐activated cation current (Ih). Ih has been related to the regulation of bursting activity in rhythmic motor networks, specifically in controlling the firing frequency of the system. Our study aims to establish the importance of Ih in mammalian locomotion under hyperdopaminergic conditions mimicking those seen in RLS patients. We hypothesized that blocking Ih would increase the cycle period and destabilize the rhythm.MethodsWe isolated the spinal cords of neonatal (P0‐P5; n = 6) Swiss Webster mice via ventral laminectomy and recorded the extracellular activity of ventral roots L2 and L5 using suction electrodes to assess burst amplitude, burst duration, and cycle period. Fictive locomotion was induced using serotonin (5HT; 9‐15μM) and N‐methyl‐D‐aspartate (NMDA; 6 μM) before adding dopamine (DA; 50μM) to determine the effect of DA on the system. We then used ZD7288 (1μM) block HCN1 channels to investigate the role of Ih in motor‐like activity.ResultsBlocking Ih caused a significant increase in all three parameters relative to the 5HT/NMDA control in the L2 roots, but only cycle period was significantly increased relative to the high dopamine condition. There were no significant changes in any of the parameters in the L5 roots.ConclusionsOur results suggest that Ih primarily plays an excitatory role in locomotor regulation under hyperdopaminergic conditions, such as those seen in RLS. The differential effects between roots may suggest that one is more susceptible to the blockade of Ih by ZD7288; however, given the large degree of variability in the L5 data, a larger sample size is needed to confirm this hypothesis. Future experiments include collecting more data on L5 to confirm if there are differential effects, as well as pharmacological approaches to confirm that D1R is upregulating Ih via the cAMP pathway.

Neonatal Mice Spinal Cord Interneurons Send Axons through the Dorsal Roots.

Spontaneous interneuron activity plays a critical role in developing neuronal networks. Discharges conducted antidromically along the dorsal root (DR) precede those from the ventral root’s (VR) motoneurons. This work studied whether spinal interneurons project axons into the neonate’s dorsal roots. Experiments were carried out in postnatal Swiss-Webster mice. We utilized a staining technique and found that interneurons in the spinal cord’s dorsal horn send axons through the dorsal roots. In vitro electrophysiological recordings showed antidromic action potentials (dorsal root reflex; DRR) produced by depolarizing the primary afferent terminals. These reflexes appeared by stimulating the adjacent dorsal roots. We found that bicuculline reduced the DRR evoked by L5 dorsal root stimulation when recording from the L4 dorsal root. Simultaneously, the monosynaptic reflex (MR) in the L5 ventral root was not affected; nevertheless, a long-lasting after-discharge appeared. The addition of 2-amino-5 phosphonovaleric acid (AP5), an NMDA receptor antagonist, abolished the MR without changing the after-discharge. The absence of DRR and MR facilitated single action potentials in the dorsal and ventral roots that persisted even in low Ca2+ concentrations. The results suggest that firing interneurons could send their axons through the dorsal roots. These interneurons could activate motoneurons producing individual spikes recorded in the ventral roots. Identifying these interneurons and the persistence of their neuronal connectivity in adulthood remains to be established.

Expression of stable and reliable preference and aversion phenotypes following place conditioning with psychostimulants.

Drug-seeking behavior occurs more readily in some individuals than others. This phenomenon is considered in studies of drug self-administration in which high drug-seeking/taking individuals can be identified. In contrast, studies of conditioned place preference (CPP) often involve a random sample of drug-naïve rodents that includes phenotypes not considered relevant to addiction. The main objective of the current studies was to determine if a priori identification of different conditioning phenotypes could improve the validity and sensitivity of CPP expression as a preclinical test for vulnerability to addiction. Analysis of cocaine place conditioning data from 443 Swiss-Webster mice revealed a trimodal distribution with peaks corresponding to means of k = 3 clusters. The cluster means occurred at high, low, or negative preference scores, the latter suggesting a phenotype acquiring conditioned place aversion (CPA). The same clusters were identified in mice conditioned with methamphetamine, MDPV, or amphetamine, and these clusters remained stable and reliable during three additional expression tests spaced at 24h. A meta-analysis of effect sizes obtained from CPP literature revealed a positively skewed distribution affected by sample size, consistent with the existence of a CPA phenotype within the populations tested. A dopamine receptor antagonist, flupentixol, blocked cocaine CPP expression in a group containing all phenotypes, but sensitivity improved markedly when CPA phenotypes were excluded from the dataset. These studies suggest that taking phenotype into consideration when designing place conditioning studies will improve their application as a preclinical tool in addiction biology and drug discovery.

Evaluation of 134Ce as a PET imaging surrogate for antibody drug conjugates incorporating 225Ac

IntroductionThe in vivo generator 134Ce/134La has the potential to serve as a PET imaging surrogate for both alpha-emitting 225Ac and 227Th radionuclides due to the unique CeIII/CeIV redox couple and the relatively long half-life of 134Ce. The purpose of this study was to demonstrate the compatibility of 134Ce with DOTA-based antibody drug conjugates, which would act as therapeutic agents when incorporating 225Ac. MethodsThe in vivo biodistributions of [134Ce]Ce-DOTA and [134Ce]Ce-citrate were assayed by microPET imaging over 25 h in Swiss Webster mice to determine the in vivo stability of the [134Ce]Ce-DOTA complex. L3-edge X-ray absorption spectroscopy measurements were used to confirm the Ce oxidation state and the formation of a fully coordinated Ce-DOTA complex. The in vivo biodistribution of [134Ce]Ce-DOTA-Trastuzumab was assayed over 147 h by microPET imaging in SK-OV-3 tumor-bearing NOD SCID mice to evaluate tumor uptake and in vivo stability. Mice were euthanized at 214 h after administration of the radiolabeled antibody conjugate, and imaged 1 h later. An ex vivo biodistribution experiment was then performed in order to corroborate the PET images. Results[134Ce]Ce-DOTA displayed rapid renal elimination and high in vivo stability over 25 h, with negligible bone and liver uptake, in comparison to [134Ce]Ce-citrate. L3-edge X-ray absorption spectroscopy experiments confirmed the 3+ oxidation state within the stable Ce-DOTA complex. MicroPET images of [134Ce]Ce-DOTA-Trastuzumab displayed elevated tumor uptake over 214 h, with minimal bone and liver uptake analogous to previously reported [225Ac]Ac-DOTA-Trastuzumab biodistribution results, and the ex vivo biodistribution of [134Ce]Ce-DOTA-Trastuzumab corroborated the final PET images. ConclusionThese results demonstrate that 134Ce allows for long-term tumor targeting with DOTA-based antibody drug conjugates and may therefore be used to trace antibody drug conjugates incorporating 225Ac.

Phytochemical Composition and Protective Effect of Vernonanthura polyanthes Leaf against In Vivo Doxorubicin-Mediated Toxicity.

Vernonanthura polyanthes (Spreng.) A.J. Vega & Dematt. (syn.: Vernonia polyanthes Less) is popularly known as “assa-peixe” and its leaves are used in folk medicine mainly to treat respiratory diseases. In this study, we evaluated the cytogenotoxic and anticytogenotoxic potential of the V. polyanthes leaf aqueous extract (VpLAE) and its n-butanol fraction (n-BF) in the presence or absence of doxorubicin (DXR) (pre-, co-, and post-treatments) on a murine model for 24 h or 120 h. The micronucleus test (MN) and the comet assay were used to assess the cytogenotoxic and anticytogenotoxic potential of VpLAE and n-BF (250, 500, and 1000 mg/kg) administered via gavage to Swiss Webster mice. The chemical profiles of VpLAE and n-BF were assessed by liquid chromatography coupled to mass spectrometry, and their metabolites were putatively identified. Lastly, the possible biological activities related to the (anti) cytogenotoxicity of the compounds were predicted using the PASS online webserver. The in vivo results showed that different doses of VpLAE and n-BF did not present cytotoxic activity; however, the MN test revealed a slight mutagenic activity for the 24 h treatments. Moderate genotoxic effects were demonstrated for all treatments in the comet assay. Regarding anticytotoxicity and antimutagenicity, VpLAE and n-BF presented a high cytoprotective potential against DXR toxic effects. In the co-treatment, VpLAE reduced the DXR genotoxicity by ~27%, and n-BF did not demonstrate antigenotoxic potential. In contrast, an antigenotoxic effect was observed for both VpLAE and n-BF in the pre- and post-treatments, reducing DXR genotoxicity by ~41% and ~47%, respectively. Chemical analysis of VpLAE and n-BF showed the presence of eight phenolic compounds, including seven chlorogenic acids and a flavonoid. The PASS online tool predicted antimutagenic, anticancer, antineoplastic, chemoprotective, antioxidant, and radical scavenging activities for all constituents identified in VpLAE and n-BF. V. polyanthes leaves presented a protective effect against DXR cytogenotoxicity. In general, VpLAE and n-BF showed a greater antigenotoxic potential in the pre- and post-treatments. The metabolites putatively identified in VpLAE and n-BF exhibited antioxidant and chemoprotective potential according to computational prediction analysis. Altogether, our results highlight the potential application of V. polyanthes to protect against toxic manifestations induced by DXR.

Anxiolytic Activity of Ethanolic Extract of Three Species of Indonesian Lempuyang (Zingiber zerumbet, Zingiber aromaticum, and Zingiber americans)

BACKGROUND: Lempuyang, or widely known as wild ginger, has been used in Indonesia as traditional medicine for a long time. However, scientific research supporting its medicinal use is still very limited. AIM: This research was conducted to investigate the anxiolytic activity of three species of Indonesian Lempuyang (Zingiber zerumbet, Zingiber aromaticum, and Zingiber americans). METHODS: Sixty-six male Swiss Webster mice were divided into 11 groups (negative control, positive control, and experiment groups consisting of low, moderate, and high dose of Z. zerumbet, Z. aromaticum, and Z. americans extract, respectively). Anxiolytic activity was evaluated by three methods: elevated plus maze test, open field test, and hole board test. RESULTS: The results showed that these three species of Indonesian Lempuyang lowered the anxiety response in elevated plus maze test, open field test, and hole board test compared to negative control (p < 0.05). The best anxiolytic activity was achieved by moderate dose of Z. americans (8.5 mg/20 gbb), consistently through three methods applied. CONCLUSION: This research supports the potential use of the ethanolic extract of Lempuyang (Z. zerumbet, Z. aromaticum, and Z. americans) as a complementary therapy for anxiety.

Attenuation of opioid tolerance by ETA receptor antagonist, BQ123, administered intravenously in mice

Intracerebroventricular injection of endothelin-A receptor antagonist BQ123 potentiates opioid analgesia and reverses analgesic tolerance. This study explores whether these effects can be replicated by injecting BQ123 intravenously. Male Swiss-Webster mice were used. Morphine tolerance was induced using 3- or 7-day dosing. Intravenous BQ123 (8mg/kg) was injected only once on Day 1, 2, 3 or 4 (3-day studies), and on Day 4, 6 or 8 (7-day studies). On Day 4 or 8, respectively, tail-flick and hot-plate latencies were measured following a morphine challenge dose. Intravenous BQ123 increased the potency and duration of morphine antinociceptive responses. In the 3-day study, the antinociceptive response was unaffected by BQ123 given on Days 1 or 2. BQ123 treatment on Day 3 or 4 (Day 4, BQ123 given 15-min before morphine) significantly potentiated antinociceptive response versus vehicle-treated tolerant mice. In 7-day studies, the antinociceptive response was unaffected by BQ123 given on Day 4. BQ123 given on Day 6 or 8 (Day 8, BQ123 given 15-min before morphine) produced a >100% increase in antinociceptive response versus vehicle-treated tolerant mice for at least 48h. Intravenous administration of BQ123 is effective in potentiating morphine analgesia and restoring antinociceptive response in morphine-tolerant mice.

Co-administration of morphine and levamisole increases death risk, produces neutropenia and modifies antinociception in mice.

Levamisole is a veterinary anthelmintic drug and a common adulterant of misused drugs. This study analyses the lethal, antinociceptive and haematological effects produced by acute or repeated levamisole administration by itself or combined with morphine. Independent groups of male Swiss Webster mice were i.p. injected with 100 mg/kg morphine, 31.6mg/kg levamisole (lethal doses at 10%, LD10 ) or the same doses combined. Naloxone pretreatment (10mg/kg, i.p.) prevented morphine-induced death, as did 2.5mg/kg, i.p. mecamylamine with levamisole. Co-administration of levamisole and morphine (Lvm + Mor) increased lethality from 10% to 80%. This augmented effect was prevented by 30 mg/kg, i.p. naloxone and reduced with 10mg/kg naloxone plus 2.5mg/kg, i.p. mecamylamine. In independent groups of mice, 17.7mg/kg, i.p. levamisole antagonized the acute morphine's antinociceptive effect evaluated in the tail-flick test. Repeated 17.7mg/kg levamisole administration (2×/day/3weeks) did not affect tolerance development to morphine (10mg/kg, 3×/day/1week). Blood samples obtained from mice repeatedly treated with levamisole showed leukopenia and neutropenia. Morphine also produced neutropenia, increased erythrocyte count and other related parameters (e.g. haemoglobin). Lvm + Mor had similar effects on leukocyte and neutrophil counts to those seen with levamisole only, but no erythrocyte-related alterations were evident. Blood chemistry analysis did not indicate liver damage but suggested some degree of electrolyte balance impairment. In conclusion, Lvm + Mor increased death risk, altered morphine-induced antinociceptive effects and produced haematologic abnormalities. The importance of studying combinations of drugs of abuse lies in the fact that drug users frequently combine drugs, which are commonly adulterated.

Oral Administration of Piperine as Curative and Prophylaxis Reduces Parasitaemia in Plasmodium berghei ANKA-Infected Mice.

Malaria remains a public health problem and a leading cause of death worldwide. Consequently, the discovery of novel agents, including substances from medicinal plants, is urgently needed. Piper nigrum has long been used by the community in the treatment of the symptoms of malaria. In a previous study, Piper nigrum was demonstrated to exhibit promising antiplasmodial activity against Plasmodium falciparum 3D7 and INDO strains. The aim of this study was to further investigate the antimalarial activity (curative and prophylactic) of piperine (a major isolated constituent of Piper nigrum) in Plasmodium berghei ANKA-infected mice. Piperine 10, 20, and 40 mg/kg body weight (bw), artesunate 5 mg/kg bw, and DMSO were administered orally for four days to different groups of Swiss Webster mice. Then, mice were monitored for parasitaemia, body weight, rectal temperature, survival rate, and clinical parameters. Piperine 40 mg/kg bw in curative and prophylactic tests had the maximum parasitaemia chemosuppression of 79.21% and 58.8% (p < 0.05), respectively, with a significant effect on the survival rate compared with control animals. In the curative test, piperine 40 mg/kg bw reduced the mean clinical score compared with the control group. Additionally, piperine showed an ability to protect organs (lungs, liver, spleen, and kidneys) from some damage in a dose-dependent manner. This study can be used as a basis for further discovery of novel chemotherapeutic or chemoprophylactic compounds.

Distinct fatty acid redistribution and textural changes in the brain tissue upon the static magnetic field exposure

We observed different outcomes upon the subacute exposure to the 128 mT highly homogeneous static magnetic field (SMF) when its orientation was (i) aligned with the vertical component of the geomagnetic field; (ii) in the opposite direction. We employed the fatty acids (FA) composition and digital image analyses (DIA) to provide insights into the underlying processes and examine the possible weak SMF effects. Swiss-Webster male mice were whole-body exposed for 1 h/day over five days. Brain tissue’s thin liquid chromatography resulted in brain FA composition, indicating a possible sequence of changes due to the SMF exposure. Quantitative DIA accurately assessed different image parameters. Delicate textural changes were revealed in the group where pathohistological or biochemical alterations have not been detected. DIA-based biological markers seem to be very promising for studying delicate tissue changes, which results from the high sensitivity and wide availability of DIA.

Effects of Sambiloto (Andrographis paniculata) Extract and Spirulina (Spirulina platensis) Administration on Ki-67 Protein Expression in the Colon Epithelial Cells of Plasmodium berghei-infected Mice

BACKGROUND: Malaria remains a global health concern and an endemic disease in Indonesia. Sambiloto (Andrographis paniculata) and spirulina (Spirulina platensis) are two potential antimalarial agents which act as antioxidants and antiinflammatories that can suppress morbidities during chronic inflammation in malaria, such as proliferation in the colon. This study aims to investigate the effects of A. paniculata extract and S. platensis administration on Ki-67 expression in medial colon epithelial cells of Plasmodium berghei-infected mice measured by H-score.METHODS: Thirty P. berghei-infected male Swiss-Webster mice were divided into five groups: negative controls (carboxymethyl cellulose/CMC); positive controls (dihydroartemisinin-piperaquine/DHP); A. paniculata extract alone (AP); A. paniculata extract in combination with S. platensis extract (AP+ES); and with S. platensis powder (AP+PS). All mice were infected with P. berghei on day 0. The treatment for each group were given 3 days before infection (D-3) until the day of infection (D0) for 28 days after infection. Colon tissues were processed with immunohistochemistry to detect Ki-67.RESULTS: A difference in Ki-67 expression was observed among the groups (p&lt;0.01). The mean H-score for the CMC control group is 135.503±6.723. The lowest level of Ki-67 expression was observed in the AP+PS group (H-score= 110.941±7.079). AP group did not show a significant difference from the CMC group (p=0.514) and neither did the AP+ES group (p=0.234).CONCLUSION: In conclusion, administration of A. paniculata extract and S. platensis powder lowers Ki-67 expression in medial colon epithelial cells of P. berghei-infected mice.KEYWORDS: malaria, spirulina, Ki-67, Andrographis paniculata, Spirulina platensis

Anthracene-Walled Acyclic CB[n] Receptors: in vitro and in vivo Binding Properties toward Drugs of Abuse.

We report studies of the interaction of six acyclic CB[n]-type receptors toward a panel of drugs of abuse by a combination of isothermal titration calorimetry and 1 H NMR spectroscopy. Anthracene walled acyclic CB[n] host (M3) displays highest binding affinity toward methamphetamine (Kd =15 nM) and fentanyl (Kd =4 nM). Host M3 is well tolerated by Hep G2 and HEK 293 cells up to 100 μM according to MTS metabolic and adenylate kinase release assays. An in vivo maximum tolerated dose study with Swiss Webster mice showed no adverse effects at the highest dose studied (44.7 mg kg-1 ). Host M3 is not mutagenic based on the Ames fluctuation test and does not inhibit the hERG ion channel. In vivo efficacy studies showed that pretreatment of mice with M3 significantly reduces the hyperlocomotion after treatment with methamphetamine, but M3 does not function similarly when administered 30 seconds after methamphetamine.

Acute Inflammation Is a Predisposing Factor for Weight Gain and Insulin Resistance.

In the course of infection and intense endotoxemia processes, induction of a catabolic state leading to weight loss is observed in mice and humans. However, the late effects of acute inflammation on energy homeostasis, regulation of body weight and glucose metabolism are yet to be elucidated. Here, we addressed whether serial intense endotoxemia, characterized by an acute phase response and weight loss, could be an aggravating or predisposing factor to weight gain and associated metabolic complications. Male Swiss Webster mice were submitted to 8 consecutive doses of lipopolysaccharide (10 mg/kg LPS), followed by 10 weeks on a high-fat diet (HFD). LPS-treated mice did not show changes in weight when fed standard chow. However, when challenged by a high-fat diet, LPS-treated mice showed greater weight gain, with larger fat depot areas, increased serum leptin and insulin levels and impaired insulin sensitivity when compared to mice on HFD only. Acute endotoxemia caused a long-lasting increase in mRNA expression of inflammatory markers such as TLR-4, CD14 and serum amyloid A (SAA) in the adipose tissue, which may represent the key factors connecting inflammation to increased susceptibility to weight gain and impaired glucose homeostasis. In an independent experimental model, and using publicly available microarray data from adipose tissue from mice infected with Gram-negative bacteria, we performed gene set enrichment analysis and confirmed upregulation of a set of genes responsible for cell proliferation and inflammation, including TLR-4 and SAA. Together, we showed that conditions leading to intense and recurring endotoxemia, such as common childhood bacterial infections, may resound for a long time and aggravate the effects of a western diet. If confirmed in humans, infections should be considered an additional factor contributing to obesity and type 2 diabetes epidemics.

Adjuvants Differentially Modulate the Immunogenicity of Lassa Virus Glycoprotein Subunits in Mice.

Lassa Fever (LF) is an acute viral hemorrhagic fever caused by Lassa virus (LASV) that is primarily transmitted through contact with wild rodents in West Africa. Although several advanced vaccine candidates are progressing through clinical trials, some effective vaccines are virally vectored and thus require a stringent cold-chain, making distribution to rural and resource-poor areas difficult. Recombinant subunit vaccines are advantageous in this aspect as they can be thermostabilized and deployed with minimal storage and transportation requirements. However, antigen dose and adjuvant formulation must be carefully selected to ensure both the appropriate humoral and cell-mediated immune responses are elicited. In this study, we examine the immunogenicity of a two-step immunoaffinity-purified recombinant LASV glycoprotein (GP) with five clinical- and preclinical-grade adjuvants. Swiss Webster mice immunized intramuscularly with 2 or 3 doses of each vaccine formulation showed complete seroconversion and maximal GP-specific antibody response after two immunizations. Formulations with GPI-0100, LiteVax, Montanide™ ISA 51, and Montanide™ ISA 720 induced both IgG1 and IgG2 antibodies suggesting a balanced Th1/Th2 response, whereas formulation of LASV GP with Alhydrogel elicited a IgG1-dominant response. Splenocytes secreting both Th1 and Th2 cytokines i.e., IFN-γ, TNF-α, IL-2, IL-4 and IL-5, were observed from mice receiving both antigen doses formulated with ISA 720, LiteVax and GPI-0100. However, robust, multifunctional T-cells were only detected in mice receiving a higher dose of LASV GP formulated with GPI-0100. Our results emphasize the importance of careful adjuvant selection and lay the immunological basis for a recombinant subunit protein LF vaccine formulation.

"Replacement of Animals Used in the Maintenance of Aedes Aegypti by Alternative Methods. Refinement of Procedures That Minimize the Discomfort of Insect Maintenance by Swiss Webster Mice"

"Replacement of Animals Used in the Maintenance of Aedes Aegypti by Alternative Methods. Refinement of Procedures That Minimize the Discomfort of Insect Maintenance by Swiss Webster Mice"

Opioid-like adverse effects of tianeptine in male rats and mice.

Tianeptine is a mu-opioid receptor (MOR) agonist with increasing reports of abuse in human populations. Preclinical data regarding the abuse potential and other opioid-like adverse effects of tianeptine at supratherapeutic doses are sparse. The present study evaluated tianeptine in a rat model of abuse potential assessment and in mouse models of motor, gastrointestinal, and respiratory adverse effects. Abuse potential was assessed in adult male Sprague-Dawley rats using an intracranial self-stimulation (ICSS) procedure to determine effects of acute and repeated tianeptine on responding for electrical brain stimulation. Male ICR mice were used to determine the effects of tianeptine in assays of locomotor behavior and gastrointestinal motility. Male Swiss-Webster mice were monitored for respiratory changes using whole-body plethysmography. In rats, acute tianeptine produced weak and delayed evidence for abuse-related ICSS facilitation at an intermediate dose (10mg/kg, IP) and pronounced, naltrexone-preventable ICSS depression at a higher dose (32mg/kg, IP). Repeated 7-day tianeptine (10 and 32mg/kg/day, IP) produced no increase in abuse-related ICSS facilitation, only modest tolerance to ICSS depression, and no evidence of physical dependence. In mice, tianeptine produced dose-dependent, naltrexone-preventable locomotor activation. Tianeptine (100mg/kg, SC) also significantly inhibited gastrointestinal motility and produced naloxone-reversible respiratory depression. Tianeptine presents as a MOR agonist with resistance to tolerance and dependence in our ICSS assay in rats, and it has lower abuse potential by this metric than many commonly abused opioids. Nonetheless, tianeptine produces MOR agonist-like acute adverse effects that include motor impairment, constipation, and respiratory depression.

Insights of OxyR role in mechanisms of host-pathogen interaction of Corynebacterium diphtheriae.

Corynebacterium diphtheriae, the leading causing agent of diphtheria, has been increasingly related to invasive diseases, including sepsis, endocarditis, pneumonia, and osteomyelitis. Oxidative stress defense is required not only for successful growth and survival under environmental conditions but also in the regulation of virulence mechanisms of human pathogenic species, by promoting mucosal colonization, survival, dissemination, and defense against the innate immune system. OxyR, functioning as a negative and/or positive transcriptional regulator, has been included among the major bacterial coordinators of antioxidant response. OxyR was first reported as a repressor of catalase expression in C. diphtheriae. However,the involvement of OxyR in C. diphtheriae pathogenesis remains unclear. Accordingly, this work aimed to investigate the role of OxyR in mechanisms of host-pathogen interaction of C. diphtheriae through the disruption of the OxyR of the diphtheria toxin (DT)-producing C. diphtheriae CDC-E8392 strain. The effects of OxyR gene disruption were analyzed through interaction assays with human epithelial cell lines (HEp-2 and pneumocytes A549) and by the induction of experimental infections in Caenorhabditis elegans nematodes and Swiss Webster mice. The OxyR disruption exerted influence on NO production and mechanism accountable for the expression of the aggregative-adherence pattern (AA) expressed by CDC-E8392 strain on human epithelial HEp-2 cells. Moreover, invasive potential and intracytoplasmic survival within HEp-2 cells, as well as the arthritogenic potential in mice, were found affected by the OxyR disruption. In conclusion, data suggest that OxyR is implicated in mechanisms of host-pathogen interaction of C. diphtheriae.

A novel preclinical model of environment-like combined benzene, toluene, ethylbenzene, and xylenes (BTEX) exposure: Behavioral and neurochemical findings

Environmental exposure to toxicants is a major health issue and a leading risk factor for premature mortality worldwide, including environmental exposures to volatile organic compounds (VOCs), specifically Benzene, Toluene, Ethylbenzene, and Xylene (BTEX). While exposure to these compounds individually has shown behavioral and neurochemical effects, this investigation examined the impact of exposure to combined BTEX using a preclinical model. Male Swiss Webster mice were exposed to BTEX vapors designed to approximate environmental levels in urban communities. Animals were exposed to one of four treatment conditions: a 0-ppm (air control), two BTEX groups representing levels of environmental-like exposure, and a fourth group modeling occupational-like exposure. These exposures were conducted in 1.5-h sessions, 2 sessions/day, 5 days/week, for 3 weeks. Effects on coordination (i.e., rotarod and inverted screen test), learning and memory (i.e., Y-maze), and locomotor behavior (i.e., movement during exposure) were assessed during and after exposure. Monoamine levels in the medial prefrontal cortex and nucleus accumbens were assessed immediately following exposure. Effects of BTEX exposure were found on the variance of locomotor activity but not in other behavioral or neurochemical assessments. These results indicate that the combination of inhaled BTEX at environmentally representative concentrations has demonstrable, albeit subtle, effects on behavior.