The rockefeller university

Fur mite outbreaks remain a persistent problem in laboratory mouse colonies. All currently published treatment methods are labor-intensive, expensive, or unreliable. During a recent outbreak with Myobia musculi and Myocoptes musculinus in a large colony (approximately 30,000 cages), we developed a feed-based treatment regime in which ivermectin was the active ingredient. Rodent feed was compounded with 3 different concentrations of ivermectin (12, 24, and 48 ppm) and gamma-irradiated. Postcompounding analysis revealed loss of ivermectin during manufacturing, but the remaining drug was stable for at least 6 mo. In an 8-wk toxicity study in a C57BL/6NTac mouse breeding colony, ad-libitum feeding of the 3 diets yielded estimated doses of 1.3, 2.7, and 5.4 mg/kg. Adult mice lacked adverse clinical effects, except that 1 of the 144 mice in the 48-ppm group developed tremors and ataxia and was euthanized. No significant differences between doses were revealed by CBC, serum chemistry, body weight, or gross necropsy. Plasma drug concentrations plateaued at a dose-dependent level 7 to 10 d after initiation of treatment and decreased to undetectable levels 6 to 9 d after its discontinuation. Fertility of the PO generation was unaffected. Pup mortality was higher in the 24- and 48-ppm groups, reaching 100% at the higher dose. Animals exposed to ivermectin as neonates had normal weaning weights, but mice receiving 24-ppm feed had lower adult weights. Our results indicate that using feed containing 12 ppm ivermectin (estimated ingested dose, 1.3 mg/kg) was safe in a C57BL/6NTac breeding colony.

During immune responses, antibodies are selected for their ability to bind to foreign antigens with high affinity, in part by their ability to undergo homotypic bivalent binding. However, this type of binding is not always possible. For example, the small number of gp140 glycoprotein spikes displayed on the surface of the human immunodeficiency virus (HIV) disfavours homotypic bivalent antibody binding(1-3). Here we show that during the human antibody response to HIV, somatic mutations that increase antibody affinity also increase breadth and neutralizing potency. Surprisingly, the responding naive and memory B cells produce polyreactive antibodies, which are capable of bivalent heteroligation between one high-affinity anti-HIV-gp140 combining site and a second low-affinity site on another molecular structure on HIV. Although cross-reactivity to self-antigens or polyreactivity is strongly selected against during B-cell development(4), it is a common serologic feature of certain infections in humans, including HIV, Epstein-Barr virus and hepatitis C virus. Seventy-five per cent of the 134 monoclonal anti-HIV-gp140 antibodies cloned from six patients(5) with high titres of neutralizing antibodies are polyreactive. Despite the low affinity of the polyreactive combining site, heteroligation demonstrably increases the apparent affinity of polyreactive antibodies to HIV.

Background: Pregnant women and infants have significant exposures to the most commonly used plasticizer di-(2-ethyl-hexyl) phthalate (DEHP). Objectives: This study was designed to evaluate the effects of DEHP exposure on growth and lung maturation in rats and determine if DEHP regulation of 11 beta-hydroxysteroid dehydrogenase type 1 gene (Hsd11b1) expression in the lung tissue plays a role in its effects on lung maturation. Method: Pregnant Sprague-Dawley rats were treated from gestational day 12 to postnatal day (PND) 21 with DEHP orally at dosages of 0, 10, 100 or 750 mg/kg/day, respectively (n=8 for each group). Two rat pups (one male and one female) from each litter were sacrificed at PND 1 and 21. Body weight was measured and the lung was processed for histology and calculation of lung interstitial tissue proportion as well as real-time PCR determination of the expressions of Hsd11b1, surfactant associated protein-A1 gene (Sftpa1) and B gene (Sftpb). Results: The perinatal DEHP exposure led to a dose dependent intrauterine and postnatal growth restriction (P<0.001). High dose DEHP (750 mg/kg/day) exposure led to decreased gas-exchange space as evidenced by increased lung interstitial tissue proportion (P<0.001), but did not cause significant changes in Hsd11b1, Sftpa1 or Sftpb gene expression in the rat lung at PND 1. The DEHP-induced change in lung histology remained significant at PND 21 with improvement despite continual exposure to DEHP. Conclusion: Perinatal DEHP exposure leads to growth restriction and delayed lung maturation in newborn rats.

Tumor necrosis factor (TNF) receptor-associated factor 3 (TRAF3) functions downstream of multiple TNF receptors and receptors that induce interferon-alpha (IFN-alpha), IFN-beta, and IFN-lambda production, including Toll-like receptor 3 (TLR3), which is deficient in some patients with herpes simplex virus-1 encephalitis (HSE). Mice lacking TRAF3 die in the neonatal period, preventing direct investigation of the role of TRAF3 in immune responses and host defenses in vivo. Here, we report autosomal dominant, human TRAF3 deficiency in a young adult with a history of HSE in childhood. The TRAF3 mutant allele is loss-of-expression, loss-of-function, dominant-negative and associated with impaired, but not abolished, TRAF3-dependent responses upon stimulation of both TNF receptors and receptors that induce IFN production. TRAF3 deficiency is associated with a clinical phenotype limited to HSE resulting from the impairment of TLR3-dependent induction of IFN. Thus, TLR3-mediated immunity against primary infection by HSV-1 in the central nervous system is critically dependent on TRAF3.

Dental enamel development occurs in stages. The ameloblast cell layer is adjacent to, and is responsible for, enamel formation. When rodent pre-ameloblasts become tall columnar secretory-stage ameloblasts, they secrete enamel matrix proteins, and the ameloblasts start moving in rows that slide by one another. This movement is necessary to form the characteristic decussating enamel prism pattern. Thus, a dynamic system of intercellular interactions is required for proper enamel development. Cadherins are components of the adherens junction (AJ), and they span the cell membrane to mediate attachment to adjacent cells. p120 stabilizes cadherins by preventing their internalization and degradation. So, we asked if p120-mediated cadherin stability is important for dental enamel formation. Targeted p120 ablation in the mouse enamel organ had a striking effect. Secretory stage ameloblasts detached from surrounding tissues, lost polarity, flattened, and ameloblast E-and N-cadherin expression became undetectable by immunostaining. The enamel itself was poorly mineralized and appeared to be composed of a thin layer of merged spheres that abraded from the tooth. Significantly, p120 mosaic mouse teeth were capable of forming normal enamel demonstrating that the enamel defects were not a secondary effect of p120 ablation. Surprisingly, blood-filled sinusoids developed in random locations around the developing teeth. This has not been observed in other p120-ablated tissues and may be due to altered p120-mediated cell signaling. These data reveal a critical role for p120 in tooth and dental enamel development and are consistent with p120 directing the attachment and detachment of the secretory stage ameloblasts as they move in rows.

Accumulation of neurotoxic amyloid-beta is a major hallmark of Alzheimer's disease(1). Formation of amyloid-beta is catalysed by gamma-secretase, a protease with numerous substrates(2,3). Little is known about the molecular mechanisms that confer substrate specificity on this potentially promiscuous enzyme. Knowledge of the mechanisms underlying its selectivity is critical for the development of clinically effective gamma-secretase inhibitors that can reduce amyloid-beta formation without impairing cleavage of other gamma-secretase substrates, especially Notch, which is essential for normal biological functions(3,4). Here we report the discovery of a novel gamma-secretase activating protein (GSAP) that drastically and selectively increases amyloid-beta production through a mechanism involving its interactions with both gamma-secretase and its substrate, the amyloid precursor protein carboxy-terminal fragment (APP-CTF). GSAP does not interact with Notch, nor does it affect its cleavage. Recombinant GSAP stimulates amyloid-beta production in vitro. Reducing GSAP concentrations in cell lines decreases amyloid-beta concentrations. Knockdown of GSAP in a mouse model of Alzheimer's disease reduces levels of amyloid-beta and plaque development. GSAP represents a type of gamma-secretase regulator that directs enzyme specificity by interacting with a specific substrate. We demonstrate that imatinib, an anticancer drug previously found to inhibit amyloid-beta formation without affecting Notch cleavage 5, achieves its amyloid-beta-lowering effect by preventing GSAP interaction with the gamma-secretase substrate, APP-CTF. Thus, GSAP can serve as an amyloid-beta-lowering therapeutic target without affecting other key functions of gamma-secretase.

Genetic defects in the IL-12-IL-23/IFN-gamma circuit confer Mendelian susceptibility to mycobacteria and salmonella. The IL-12/IFN-gamma axis is essential for anti-tumoral immunity in mice. Cancer susceptibility has not been recognised in these patients so far. We report three relatives with IL-12R beta 1 deficiency. At the age of 25 years old, one patient presented with oesophageal squamous cell carcinoma (OSCC). The patient had no previous risk factors for OSCC. He died at the age of 29 years. OSCC is exceedingly rare in individuals under 30 years and frecuently relates to alcohol intake and smoking. Disorders of the IL-12-IL-23/IFN-gamma axis may predispose to cancer.

Hearing depends on reliable and temporally precise neurotransmission by cochlear hair cells. The wide dynamic range and high sensitivity with which these cells encode acoustic stimuli are associated with a presynaptic specialization termed the presynaptic dense body or synaptic ribbon. Apposed to the presynaptic density, this spherical or flattened structure tethers a layer of synaptic vesicles and is thought to facilitate their exocytotic fusion. Although defining the molecular constituents of the hair cell's synaptic ribbon should contribute to our understanding of neurotransmitter release at this synapse, accomplishing this task has been slowed by the difficulty of obtaining sufficient amounts of starting material for protein analysis from hair cells. We isolated synaptic material from chicken cochleas, purified synaptic ribbons with specific immunological reagents, and identified the associated proteins by tandem mass spectrometry. Purification of the ribbons revealed a predominant composition of C-terminal-binding proteins, especially ribeye, in association with the small GTPase Rab3, which is possibly involved in attaching vesicles to the ribbon. In comparison with the components of conventional synapses and of retinal ribbon synapses, we observed that certain regulatory proteins are excluded from the hair cell's synapse. Using antisera against several of the novel proteins and membrane-trafficking components that we had identified, we documented their localization in isolated hair cells. Our results indicate that the ribbon synapses of hair cells display modifications to the presynaptic machinery that are associated with the high-fidelity transmission of acoustic signals to the brain.

We present results of a search for anomalous production of two photons together with an electron, muon, tau lepton, missing transverse energy, or jets using p (p) over bar collision data from 1.1-2.0 fb(-1) of integrated luminosity collected by the Collider Detector at Fermilab (CDF). The event yields and kinematic distributions are examined for signs of new physics without favoring a specific model of new physics. The results are consistent with the standard model expectations. The search employs several new analysis

An examination of the micro-organization of visual cortex using two-photon calcium imaging provides a new level of insight into retinotopic maps, finding that retinotopy is scrambled on fine scales in mouse primary visual cortex.