Detection of recombinant and endogenous mouse melatonin receptors by monoclonal antibodies targeting the C‐terminal domain

Melatonin receptors play important roles in the regulation of circadian and seasonal rhythms, sleep, retinal functions, the immune system, depression, and type 2 diabetes development. Melatonin receptors are approved drug targets for insomnia, non‐24‐hour sleep‐wake disorders, and major depressive disorders. In mammals, two melatonin receptors (MTRs) exist, MT₁ and MT₂, belonging to the G protein‐coupled receptor (GPCR) superfamily. Similar to most other GPCRs, reliable antibodies recognizing melatonin receptors proved to be difficult to obtain. Here, we describe the development of the first monoclonal antibodies (mABs) for mouse MT₁ and MT₂. Purified antibodies were extensively characterized for specific reactivity with mouse, rat, and human MT₁ and MT₂ by Western blot, immunoprecipitation, immunofluorescence, and proximity ligation assay. Several mABs were specific for either mouse MT₁ or MT₂. None of the mABs cross‐reacted with rat MTRs, and some were able to react with human MTRs. The specificity of the selected mABs was validated by immunofluorescence microscopy in three established locations (retina, suprachiasmatic nuclei, pituitary gland) for MTR expression in mice using MTR‐KO mice as control. MT₂ expression was not detected in mouse insulinoma MIN6 cells or pancreatic beta‐cells. Collectively, we report the first monoclonal antibodies recognizing recombinant and native mouse melatonin receptors that will be valuable tools for future studies.     

Synthesis of 13C-labeled parabens from isotopically enriched phenols using the Houben–Hoesch reaction

Parabens are antimicrobial additives found in a wide array of consumer products. However, the halogenated compounds formed from parabens during wastewater disinfection are a potential environmental concern. In order to identify these transformation products and investigate their mechanism of formation, a synthetic route to ethyl parabens labeled with the stable isotope carbon-13 at specific positions within the benzene ring was developed. This efficient two-step procedure starts from commercially available ¹³C-labeled phenols and involves (1) initial acylation of the phenol via a Houben–Hoesch reaction with trichloroacetonitrile followed by (2) a modified haloform reaction of the resulting trichloromethyl ketone to afford the corresponding ¹³C-labeled ethyl parabens in 65%–80% overall yield. The scope of the modified haloform reaction was also investigated, allowing for the synthesis of other parabens derived from primary or secondary alcohols, including ¹³C- and deuterium-labeled esters. In addition, 4-hydroxybenzoic acid can be formed directly from the common trichloromethyl ketone intermediate upon treatment with lithium hydroxide. This protocol complements existing methods for preparing ¹³C-labeled paraben derivatives and offers the specific advantages of exhibiting complete regioselectivity in the Houben–Hoesch reaction (to form the para-disubstituted product) and avoiding the need for protecting groups in the modified haloform reaction that forms the paraben esters.     

Ceftaroline fosamil for the treatment of Gram-positive endocarditis: CAPTURE study experience

Background

The clinical experience of ceftaroline fosamil (CPT-F) therapy for Gram-positive infective endocarditis is reported from CAPTURE, a retrospective study conducted in the USA.

Self-regulation and social and behavioral functioning following childhood traumatic brain injury.

This study examined the impact of childhood traumatic brain injury (TBI) on self-regulation and social and behavioral functioning, and the role of self-regulation as a predictor of children's social and behavioral functioning. Participants included 65 children with moderate to severe TBI and 65 children without TBI, all between 6 and 11 years of age. Self-regulation and social and behavioral functioning were assessed 2 to 5 years following injury. Children with TBI displayed deficits in self-regulation and social and behavioral functioning, after controlling for socioeconomic status (SES), although the magnitude of the deficits was not related to injury severity. Self-regulation accounted for significant variance in children's social and behavioral functioning, after controlling for SES and group membership. Self-regulation may be an important determinant of children's social and behavioral functioning following TBI.     

Development of autoimmune hepatitis in primary biliary cirrhosis.

AIM/BACKGROUND: Primary biliary cirrhosis (PBC) is a chronic cholestatic liver disease of unknown aetiology. Up to 10% of patients with typical features of PBC will have additional features of autoimmune hepatitis (AIH). A subset, however, have no such features but go on to develop a 'sequential' AIH overlap syndrome. Objectives: Describe our experience with eight patients who developed AIH after the diagnosis of PBC was made. METHODS: We reviewed the charts of all PBC patients over a 9-year period (from 1996 to 2005). Only PBC patients with no features of AIH were included. RESULTS: There were 1476 patients with PBC. Of these, eight patients developed features of AIH overlap syndrome based on biochemical and histological parameters. Treatment included prednisone and azathioprine for 24 or more months. The majority of patients remained on ursodeoxycholic acid (UDCA) throughout treatment. Response to therapy was defined by improvement in enzymes, and was rapid for all patients. One patient was able to discontinue treatment with prednisone and azathioprine, while seven have continued on therapy to date. CONCLUSIONS: A 'sequential' overlap syndrome of AIH with PBC can occur. Treatment with prednisone and azathioprine may lead to a rapid improvement in aminotransferase levels.