Decreased Hsp90 activity protects against TDP-43 neurotoxicity in a C. elegans model of amyotrophic lateral sclerosis.

Neuronal inclusions of hyperphosphorylated TDP-43 are hallmarks of disease for most patients with amyotrophic lateral sclerosis (ALS). Mutations in TARDBP, the gene coding for TDP-43, can cause some cases of familial inherited ALS (fALS), indicating dysfunction of TDP-43 drives disease. Aggregated, phosphorylated TDP-43 may contribute to disease phenotypes; alternatively, TDP-43 aggregation may be a protective cellular response sequestering toxic protein away from the rest of the cell.

Hereditary spastic paraplegia with thin corpus callosum and SPG11 mutation: A neuropathological evaluation.

Hereditary spastic paraplegia (HSP) with thin corpus callosum can be due to a variety of genetic causes, the most common of which are biallelic variants in SPG11 (HSP11). Only six cases of neuropathologic examination of HSP11 have been reported. Here we present neuropathological findings in another case of HSP11 with novel mutation (homozygous c.

Nitric oxide induces the distinct invisibility phenotype of Mycobacterium tuberculosis.

During infection Mycobacterium tuberculosis (Mtb) forms physiologically distinct subpopulations that are recalcitrant to treatment and undetectable using standard diagnostics. These difficult to culture or differentially culturable (DC) Mtb are revealed in liquid media, their revival is often stimulated by resuscitation-promoting factors (Rpf) and prevented by Rpf inhibitors. Here, we investigated the role of nitric oxide (NO) in promoting the DC phenotype.

Transcriptomic evaluation of tau and TDP-43 synergism shows tauopathy predominance and reveals potential modulating targets.

Alzheimer's disease (AD), the most common aging-associated neurodegenerative dementia disorder, is defined by the presence of amyloid beta (Aβ) and tau aggregates in the brain. However, more than half of patients also exhibit aggregates of the protein TDP-43 as a secondary pathology. The presence of TDP-43 pathology in AD is associated with increased tau neuropathology and worsened clinical outcomes in AD patients.

Stem Cell Transplant in Immune-deficiency-associated Vaccine-derived Poliovirus.

Patients with severe primary immunodeficiency are at risk for complications from live-attenuated vaccines. Here, we report a case of a vaccine-associated paralytic polio and Bacille Calmette-Guérin disease in a 6-month-old girl with severe combined immunodeficiency resulting from homozygous recombinant activating gene 1 deficiency. The patient was successfully treated with intravenous immunoglobulins and oral pocapavir for poliovirus, and antimycobacterial therapy for regional Bacille Calmette-Guérin disease, allowing stem cell transplant.

TDP-43 promotes tau accumulation and selective neurotoxicity in bigenic Caenorhabditis elegans.

Although amyloid β (Aβ) and tau aggregates define the neuropathology of Alzheimer's disease (AD), TDP-43 has recently emerged as a co-morbid pathology in more than half of patients with AD. Individuals with concomitant Aβ, tau and TDP-43 pathology experience accelerated cognitive decline and worsened brain atrophy, but the molecular mechanisms of TDP-43 neurotoxicity in AD are unknown. Synergistic interactions among Aβ, tau and TDP-43 may be responsible for worsened disease outcomes.

Generation of Distinct Differentially Culturable Forms of following Starvation at Low Temperature.

Bacteria have developed unique mechanisms to adapt to environmental stresses and challenges of the immune system. Here, we report that Burkholderia pseudomallei, the causative agent of melioidosis, and its laboratory surrogate, Burkholderia thailandensis, utilize distinct mechanisms for surviving starvation at different incubation temperatures. At 21°C, are present as short rods which can rapidly reactivate and form colonies on solid media.

A Phase 1 Study of the Safety, Tolerability, and Pharmacokinetics of Single and Multiple Oral Doses of V-7404 in Healthy Adult Volunteers.

V-7404, a direct-acting enterovirus (EV) 3C protease inhibitor, is being developed as a treatment option for serious EV infections, including infections in immunodeficient people excreting vaccine-derived polioviruses. V-7404 may be combined with pocapavir (V-073), a capsid inhibitor, to treat these infections. A phase 1 single ascending dose (SAD;  = 36) and multiple ascending dose (MAD;  = 40) study was conducted to assess the safety, tolerability, and pharmacokinetics (PK) of V-7404 in healthy adult volunteers following oral doses starting at 200 mg and escalating to 2,000 mg once daily (QD) and 2,000 mg twice daily (BID).

Clearance of Immunodeficiency-associated Vaccine-derived Poliovirus Infection With Pocapavir.

Pocapavir exhibits antiviral activity against both polio and nonpolio enteroviruses. There is limited experience of the use of this investigational drug in young children with enteroviral infection. We describe the successful clearance of prolonged immunodeficiency-associated vaccine-derived type 3 poliovirus infection by pocapavir in an infant with underlying X-linked agammaglobulinemia.

Antiviral Activity of Pocapavir in a Randomized, Blinded, Placebo-Controlled Human Oral Poliovirus Vaccine Challenge Model.

Background: Immunodeficient individuals who excrete vaccine-derived polioviruses threaten polio eradication. Antivirals address this threat.

Methods: In a randomized, blinded, placebo-controlled study, adults were challenged with monovalent oral poliovirus type 1 vaccine (mOPV1) and subsequently treated with capsid inhibitor pocapavir or placebo.

Progress in the development of poliovirus antiviral agents and their essential role in reducing risks that threaten eradication.

Chronic prolonged excretion of vaccine-derived polioviruses by immunodeficient persons (iVDPV) presents a personal risk of poliomyelitis to the patient as well as a programmatic risk of delayed global eradication. Poliovirus antiviral drugs offer the only mitigation of these risks. Antiviral agents may also have a potential role in the management of accidental exposures and in certain outbreak scenarios.

Differences in respiratory syncytial virus and influenza infection in a house-dust-mite-induced asthma mouse model: consequences for steroid sensitivity.

A significant number of clinical asthma exacerbations are triggered by viral infection. We aimed to characterize the effect of virus infection in an HDM (house dust mite) mouse model of asthma and assess the effect of oral corticosteroids. HDM alone significantly increased eosinophils, lymphocytes, neutrophils, macrophages and a number of cytokines in BAL (bronchoalveolar lavage), all of which were sensitive to treatment with prednisolone (with the exception of neutrophils).

Anti-inflammatory modulation of chronic airway inflammation in the murine house dust mite model.

Asthma affects 300 million people worldwide and continues to be a major cause of morbidity and mortality. Disease relevant animal models of asthma are required for benchmarking of novel therapeutic mechanisms in comparison to established clinical approaches. We demonstrate that chronic exposure of mice to house dust mite (HDM) extract results in allergic airway inflammation, that can be significantly attenuated by therapeutic intervention with phosphodiesterase 4 inhibition and corticosteroid treatment.

Immunotoxicology assessment in the pharmaceutical industry.

Through several inter-laboratory evaluation studies, selected methods were optimized and evaluated using reference compounds in rodents, to determine their predictive value for detecting toxicity to the immune system. These provide the basis for the OECD, EPA and pending FDA Guidelines. To describe the status of immunotoxicity evaluation using these methods in the pharmaceutical industry, a survey was conducted, and is reported, of ongoing activities among the major pharmaceutical companies.

Pharmacokinetics of the hypoxic cell cytotoxic agent tirapazamine and its major bioreductive metabolites in mice and humans: retrospective analysis of a pharmacokinetically guided dose-escalation strategy in a phase I trial.

Tirapazamine (3-amino-1,2,4-benzotriazine-1,4-di-N-oxide; SR 259075) is a selective hypoxic cell cytotoxic agent that is bioreductively activated in tumours to a reactive-drug free radical. Preclinically the agent has been shown to possess additive and synergistic anti-tumour activity in combination with radiotherapy and chemotherapy regimens. In the present study the pharmacokinetics and metabolism of tirapazamine were investigated in mice and patients as part of pre-clinical and phase I investigations.

Induction of liver cytochrome P-450 (CYP) 3A in male and female rats by a steroidal androgen receptor antagonist, zanoterone.

The cytochrome P-450 (CYP) mediated hydroxylation of testosterone to 6 beta-, 7 alpha-, and 16 alpha-hydroxytestosterone (b beta-, 7 alpha-, and 16 alpha-OHT) and the dealkylation of ethoxycoumarin to 7-hydroxycoumarin (ECOD) and ethoxyresorufin to resorufin (EROD) were used to probe changes in CYP monooxygenase activities in liver microsomes from rats treated with the androgen receptor antagonist, zanoterone (Z). Phenobarbital (PB) and beta-naphthoflavone (beta-NF) were used as comparators. There were sex-related differences in the constitutive CYP activities and in the responses of CYP activities to Z.

The integration of immunotoxicology in drug discovery and development: Investigative and in vitro possibilities.

The development of new pharmaceuticals requires a tremendous investment of time and resources. The early integration of investigative toxicology studies and new toxicological methods, such as immunotoxicological studies, into the selection of new drug candidates facilities compound safety evaluation, reduces risk, and improves development cycle time. Experience at Sterling Winthrop Inc.

DNA cross-linking in mammalian cells by pyrrolizidine alkaloids: structure-activity relationships.

Pyrrolizidine alkaloids (PAs) are common constituents of many species of flowering plants which possess carcinogenic as well as anticarcinogenic activity in vivo. Pyrrolizidine alkaloids are genotoxic in various short-term assays. The mechanisms by which these compounds exert these effects is still unclear.

In vitro studies on the mechanism of action of hepsulfam in chronic myelogenous leukemia patients.

In the present study we have characterized the cytotoxicity and DNA damage induced by hepsulfam and busulfan in cells isolated from both chronic myelogenous leukemia (CML) patients and normal donors. hepsulfam inhibited colony-forming units-granulocyte, macrophage to a greater extent than busulfan in peripheral blood cells (PBCs) isolated from CML patients. Normal PBCs were equally sensitive to both agents and were more sensitive than the cells isolated from CML patients.

Mechanisms of toxicity of hepsulfam in human tumor cell lines.

1,7-Heptanediol disulfamate (hepsulfam, NSC 329680) is a new anti-cancer agent which is currently undergoing phase I clinical trials. The mechanism of action of this compound is not clear at this time. We have recently shown that hepsulfam was more toxic to L1210 leukemia cells than was busulfan.

Rapid detection of DNA-interstrand and DNA-protein cross-links in mammalian cells by gravity-flow alkaline elution.

Alkaline elution is a sensitive and commonly used technique to detect cellular DNA damage in the form of DNA strand breaks and DNA cross-links. Conventional alkaline elution procedures have extensive equipment requirements and are tedious to perform. Our laboratory recently presented a rapid, simplified, and sensitive modification of the alkaline elution technique to detect carcinogen-induced DNA strand breaks.

Effects of phenytoin and carbamazepine on human natural killer cell activity and genotoxicity in vitro.

Human peripheral blood mononuclear cells (PBMC) were isolated from healthy volunteers and exposed in vitro to phenytoin or carbamazepine, two widely used antiepileptic drugs (AED). This study investigated the effects of these drugs on natural killer (NK) cell activity and antibody-dependent cell-mediated cytotoxicity (ADCC), which are both thought to protect against developing neoplasms. Also, the genotoxicity of phenytoin on human PBMC was investigated by gravity-flow alkaline elution.

Effects of inducer pretreatment on liver function and morphology in the mountain vole Microtus montanus.

Liver function and morphology of the mountain vole, Microtus montanus, were examined after i.p. injections of phenobarbital, beta-naphthoflavone, or Aroclor 1254 at three dose levels.