Galantamine is a novel post-exposure therapeutic against lethal VX challenge.

The ability of galantamine hydrobromide (GAL HBr) treatment to antagonize O-ethyl-S-(2-diisopropylaminoethyl) methylphosphonothiolate (VX)-induced lethality, impairment of muscle tension, and electroencephalographic (EEG) changes was assessed in guinea pigs. Guinea pigs were challenged with 16.8 microg/kg VX (2LD50). One min after challenge, animals were administered 0.5 mg/kg atropine sulfate (ATR) and 25 mg/kg pyridine-2-aldoxime methochloride (2-PAM). In addition, guinea pigs were given 0, 1, 2, 4, 8 or 10 mg/kg GAL as a post-exposure treatment immediately prior to ATR and 2-PAM. Animals were either monitored for 24-h survival, scheduled for electroencephalography (EEG) recording, or euthanized 60 min later for measurement of indirectly-elicited muscle tension in the hemidiaphragm. Post-exposure GAL therapy produced a dose-dependent increase in survival from lethal VX challenge. Optimal clinical benefits were observed in the presence of 10 mg/kg GAL, which led to 100% survival of VX-challenged guinea pigs. Based on muscle physiology studies, GAL post-exposure treatment protected the guinea pig diaphragm, the major effector muscle of respiration, from fatigue, tetanic fade, and muscular paralysis. Protection against the paralyzing effects of VX was dose-dependent. In EEG studies, GAL did not alter seizure onset for all doses tested. At the highest dose tested (10 mg/kg), GAL decreased seizure duration when administered as a post-exposure treatment 1 min after VX. GAL also reduced the high correlation associated between seizure activity and lethality after 2LD50 VX challenge. GAL may have additional benefits both centrally and peripherally that are unrelated to its established mechanism as a reversible acetylcholinesterase inhibitor (AChEI).

A novel variant of Inpp5f is imprinted in brain, and its expression is correlated with differential methylation of an internal CpG island.

Using a tissue-specific microarray screen in combination with chromosome anomalies in the mouse, we identified a novel imprinted gene, Inpp5f_v2 on mouse chromosome 7. Characterization of this gene reveals a 3.2-kb transcript that is paternally expressed in the brain. Inpp5f_v2 is a variant of the related 4.7-kb transcript, Inpp5f, an inositol phosphatase gene that is biallelically expressed in the mouse. Inpp5f_v2 uses an alternative transcriptional start site within an intron of Inpp5f and thus has a unique alternative first exon. Whereas other imprinted transcripts have a unique first exon located within intron 1 of a longer transcript variant (such as at the Gnas and WT1 loci), Inpp5f_v2 is the first example of which we are aware in which the alternative first exon of an imprinted gene is embedded in a downstream intron (intron 15) of a transcript variant. The CpG island associated with the non-imprinted Inpp5f gene is hypomethylated on both alleles, a finding consistent with biallelic expression, whereas the CpG island present 5' of Inpp5f_v2 is differentially methylated on the maternal versus paternal alleles consistent with its imprinting status.

A new device for the capture and transport of small nonhuman primates in scientific research.

Conventional methods of capturing marmosets and other small nonhuman primates (NHPs) require prolonged physical contact between animals and their handlers. This causes NHPs to become stressed and exhausted and can put both animals and handlers at risk of injury or exposure to infectious diseases. The authors designed a self-contained device for the capture and transport of small NHPs. Food rewards encourage primates to enter the device independently, and handlers can then easily access the animals for routine veterinary or experimental procedures. Preliminary observations suggest that marmosets quickly become accustomed to the device and that the device causes less stress than capture by hand or by net.

Characterization of Notch receptor expression in the developing mammalian heart and liver.

Alagille syndrome (AGS) is an autosomal dominant disorder characterized by bile duct paucity along with cardiovascular, skeletal, and ophthalmologic defects. The identification of JAG1 as the AGS disease gene revealed the crucial role of the Notch signaling pathway in the development of multiple organ systems in humans. Patients with identical mutations in JAG1 demonstrate extreme clinical variability, suggesting that other factors may influence the severity of the developmental defects in this disorder. We have defined the temporal and spatial expression patterns of the Notch receptor genes in the developing mammalian heart and liver in order to identify potential ligand/receptor interactions during embryogenesis. In the developing heart, both Notch1 and Notch2 are expressed in the outflow tracts and the epicardium, in specific cell populations previously shown to express JAG1. These cells are destined to undergo epithelial-to-mesenchymal transformation. In the newborn mouse liver, Notch2 and Notch3 are expressed in opposing cell populations, suggesting they play different roles in cell fate determination during bile duct development. JAG1 is also expressed in cells adjacent to those expressing Notch2, suggesting a possible ligand receptor relationship. The Notch receptors have distinct roles in cell fate determination in different organ systems.

A nerve clamp electrode design for indirect stimulation of skeletal muscle.

A nerve clamp electrode was developed to indirectly stimulate skeletal muscle innervated by α motor neurons as an alternative to conventional electrodes. The stimulating electrode device consists of a spring coil-activated nerve clamp mounted inside a 1-mL syringe barrel. Supramaximal pulses were generated by a Grass stimulator and delivered to the nerve segment via the nerve clamp electrode. The salient feature of the electrode is its ability to produce muscle contractions indirectly through stimulation of the attached nerve. Indirect muscle stimulation is critical for studying the paralytic actions of presynaptic-acting toxins such as botulinum neurotoxins (BoNT), a potent inhibitor of acetylcholine (ACh) release from α motor neurons. This device enables stimulation of muscle contraction indirectly as opposed to contraction from direct muscle stimulation. The electrode is able to stimulate indirect muscle contraction when tested on ex vivo preparations from rodent phrenic nerve-hemidiaphragm muscle in similar fashion to conventional electrodes. In addition, the electrode stimulated external intercostal nerve-muscle preparations. This was confirmed after applying BoNT serotype A, a potent inhibitor of ACh release, to induce muscle paralysis. Alternative methods, including suction and bipolar loop electrodes, were unsuccessful in stimulating indirect muscle contraction. Therefore, this novel electrode is useful for physiological assessment of nerve agents and presynaptic actions of toxins that cause muscle paralysis. This electrode is useful for stimulating nerve-muscle preparations for which the length of nerve is a concern.

Familial basaloid follicular hamartoma: lesional characterization and review of the literature.

Basaloid follicular hamartoma (BFH) is a rare cutaneous lesion associated with the acquisition of small papules that remain stable for many years. Basaloid follicular hamartoma lesions can present sporadically or as part of an inherited syndrome. Occasionally, biopsies of BFH lesions are interpreted as basal cell carcinoma (BCC), which necessitates complete removal of the lesion. In this report, we characterize a case of a familial BFH syndrome and discuss the clinical, histologic, and molecular features of BFH lesions that help to distinguish it from BCC. The BFH lesions in our patients remained stable for many years. Histologically, BFH lesions exhibit fewer mitoses and decreased single cell necrosis when compared with BCC. Immunohistochemical staining for the proliferation markers proliferating cell nuclear antigen and Ki-67 demonstrated less staining in BFH than in BCC. In addition, levels of PTCH (patched) mRNA were increased relative to unremarkable epidermis in familial BFH lesions but to a lesser degree and in a different pattern than that seen in BCC. In summary, familial BFH can be distinguished from BCC based on clinical, histologic, and molecular features and is associated with deregulation of the PTCH pathway. Basaloid follicular hamartoma may represent an indolent lesion within the spectrum of basaloid epithelial neoplasms associated with deregulation of the PTCH signaling pathway. We discuss this case in parallel with a growing body of literature that supports the nosologic designation of BFH.