Evaluating the Role of Susceptibility Inducing Cofactors and of Acetaminophen in the Etiology of Autism Spectrum Disorder.

More than 20 previously reported lines of independent evidence from clinical observations, studies in laboratory animal models, pharmacokinetic considerations, and numerous temporal and spatial associations indicate that numerous genetic and environmental factors leading to inflammation and oxidative stress confer vulnerability to the aberrant metabolism of acetaminophen during early development, leading to autism spectrum disorder (ASD). Contrary to this conclusion, multivariate analyses of cohort data adjusting for inflammation-associated factors have tended to show little to no risk of acetaminophen use for neurodevelopment. To resolve this discrepancy, here we use in silico methods to create an ideal (virtual) population of 120,000 individuals in which 50% of all cases of virtual ASD are induced by oxidative stress-associated cofactors and acetaminophen use.

The Dangers of Acetaminophen for Neurodevelopment Outweigh Scant Evidence for Long-Term Benefits.

Based on available data that include approximately 20 lines of evidence from studies in laboratory animal models, observations in humans, correlations in time, and pharmacological/toxicological considerations, it has been concluded without reasonable doubt and with no evidence to the contrary that exposure of susceptible babies and children to acetaminophen (paracetamol) induces many, if not most, cases of autism spectrum disorder (ASD). However, the relative number of cases of ASD that might be induced by acetaminophen has not yet been estimated. Here, we examine a variety of evidence, including the acetaminophen-induced reduction of social awareness in adults, the prevalence of ASD through time, and crude estimates of the relative number of ASD cases induced by acetaminophen during various periods of neurodevelopment.

Acetaminophen causes neurodevelopmental injury in susceptible babies and children: no valid rationale for controversy.

Despite the worldwide acceptance of acetaminophen (APAP) as a necessary medicine in pediatrics, evidence that early exposure to APAP causes neurodevelopmental injury in susceptible babies and children has been mounting for over a decade. The evidence is diverse and includes extensive work with laboratory animals, otherwise unexplained associations, factors associated with APAP metabolism, and limited studies in humans. Although the evidence has reached an overwhelming level and was recently reviewed in detail, controversy persists.

The safety of pediatric use of paracetamol (acetaminophen): a narrative review of direct and indirect evidence.

Paracetamol (acetaminophen) use during pregnancy and early childhood was accepted as safe in the 1970s, but is now a subject of considerable concern. Careful analysis shows that initial acceptance of the drug was based on the false assumption that drug interactions in babies and adults are the same, and on a complete absence of knowledge regarding the impact of the drug on brain development. At least fourteen epidemiological studies now indicate that prenatal exposure to paracetamol is associated with neurodevelopmental problems.

Therapeutic doses of acetaminophen with co-administration of cysteine and mannitol during early development result in long term behavioral changes in laboratory rats.

Based on several lines of evidence, numerous investigators have suggested that acetaminophen exposure during early development can induce neurological disorders. We had previously postulated that acetaminophen exposure early in life, if combined with antioxidants that prevent accumulation of NAPQI, the toxic metabolite of acetaminophen, might be innocuous. In this study, we administered acetaminophen at or below the currently recommended therapeutic dose to male laboratory rat pups aged 4-10 days.

Improving the oral bioavailability of buprenorphine: an in-vivo proof of concept.

Objectives: The aim of this study was to improve the oral bioavailability of buprenorphine by inhibiting presystemic metabolism via the oral co-administration of 'Generally Recognized as Safe' compounds, thus providing an orally administered drug product with less variability and comparable or higher exposure compared with the sublingual route.

Methods: The present studies were performed in Sprague Dawley rats following either intravenous or oral administration of buprenorphine/naloxone and oral co-administration of 'Generally Recognized as Safe' compounds referred to as 'adjuvants'. Plasma samples were collected up to 22 h postdosing followed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) analysis.

Epigenetic histone acetylation and deacetylation mechanisms in experimental models of neurodegenerative disorders.

Introduction: Epigenetic modifications, such as histone acetylation and deacetylation, are responsible for maintaining chromatin stability. As such, they have been implicated in a wide range of neurodegenerative disorders.

Methods: Histone acetylation involves the presentation of an acetyl group to lysine residues at the N terminus of histone proteins.

Histone deacetylase inhibitor: antineoplastic agent and radiation modulator.

Inhibitors of histone deacetylases (HDACs) have emerged as a new class of anticancer agents based on their actions in cancer cell growth and cell cycle arrest, terminal differentiation, and apoptosis. Previously, we rationally designed and developed a new class of hydroxamide- and mercaptoacetamide-bearing HDAC inhibitors. A subset of these inhibitors exhibited chemo-radiation sensitizing properties in various human cancer cells.

Adamantanyl-histone deacetylase inhibitor H6CAHA exhibits favorable pharmacokinetics and augments prostate cancer radiation sensitivity.

Purpose: To evaluate pharmacological properties of H6CAHA, an adamantyl-hydroxamate histone deacetylase inhibitor, and to investigate its effect on prostate cancer cells following exposure to γ-radiation in vitro and in vivo.

Methods And Materials: H6CAHA was assessed for in vitro solubility, lipophilicity and growth inhibition, and in vivo plasma pharmacokinetics. The effect of H6CAHA on radiation clonogenic survival and DNA damage repair was evaluated in human prostate cancer (PC3, DU145, LNCaP) and nonmalignant control epithelial (RWPE1 and 267B1) cell lines.

Pharmacokinetics-pharmacodynamics and antitumor activity of mercaptoacetamide-based histone deacetylase inhibitors.

Structurally diverse histone deacetylase inhibitors (HDACI) have emerged as chemotherapeutic agents. Here, we report the first mercaptoacetamide HDACIs (coded 6MAQH and 5MABMA) for use in treatment against prostate cancer cells in vitro and in vivo and correlate their plasma pharmacokinetics and tissue-pharmacodynamics with tumor sensitivity. HDACIs were assessed for in vitro microsomal stability and growth inhibition against prostate cancer and nonmalignant cells.

Involvement of P-glycoprotein and multidrug resistance associated protein 1 on the transepithelial transport of a mercaptoacetamide-based histone-deacetylase inhibitor in Caco-2 cells.

Oral bioavailability is one of the important criteria for development of a drug-lead candidate. In this study, the absorptive characteristics and the efflux mechanism of a mercaptoacetamide-based histone deacetyalse (HDAC) inhibitor, coded as W2, were investigated using Caco-2 cells. The transport of W2 was asymmetric as indicated by 1.