509 research outputs found

    English local government in the 16th and 17th centuries

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    Thesis (M.A.)--Boston Universit

    South American Beef

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    Veterinarians have an active interest in the question of the importation of South American beef into this country. During the prolonged controversy which has raged over this question, they have lined up, in general, with livestock men in opposing measures which would allow South American beef to be imported into the United States in any considerable degree. In both cases, those opposed to importation do not always consider all the facts bearing on the problem; and many opposing arguments fail to distinguish between the importation of fresh beef and that of canned beef

    The impact of host-microbe interactions on murine colonic secretomotor function

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    The overall objective of this thesis was to gain further insight into the mechanisms underlying commensal microbial influences on intestinal ion transport. In this regard, I examined the impact of commensal host-microbe interactions on colonic secretomotor function in mouse. I first examined the influence of two different probiotic (microorganisms which, when given in adequate amounts, can confer health benefits upon the host) strains, Bifidobacterium infantis 35624 and L. salivarius UCC118 on active colonic ion transport in the mouse, using the Ussing Chamber. I found that both probiotics appear to have converging effects on ion transport at a functional level. However, L. salivarius UCC118 may preferentially inhibit neurally-evoked ion transport. Next I examined the impact of the host microbiota itself on both baseline and stimulated colonic secretomotor function as well as probiotic induced changes in ion transport. I provide further evidence that the microbiota is capable of mediating alterations in colonic ion transport, and specifically suggests that it can influence cAMP-mediated responses. Finally, it has been well documented that many probiotics elicit their effects via secreted bioactives, therefore, I studied the effects of microbially produced GABA, contained in supernatants from the commensal microbe Lactobacillus brevis DPC6108, on colonic secretomotor function. In conclusion, I believe that commensal microbes have an important and strain specific functional influence on colonic ion transport and secretomotor function and these effects can be mediated via extracellular bioactives. Moreover, I believe that functional ex-vivo studies such as those carried out in this thesis have a critical role to play in our future understanding of host-microbe interactions in the gut

    A single amino acid substitution in the pleckstrin homology domain of phospholipase C delta1 enhances the rate of substrate hydrolysis.

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    The pleckstrin homology (PH) domain has been postulated to serve as an anchor for enzymes that operate at a lipid/water interface. To understand further the relationship between the PH domain and enzyme activity, a phospholipase C (PLC) delta1/PH domain enhancement-of-activity mutant was generated. A lysine residue was substituted for glutamic acid in the PH domain of PLC delta1 at position 54 (E54K). Purified native and mutant enzymes were characterized using a phosphatidylinositol 4,5-bisphosphate (PI(4, 5)P2)/dodecyl maltoside mixed micelle assay and kinetics measured according to the dual phospholipid model of Dennis and co-workers (Hendrickson, H. S., and Dennis, E. A. (1984) J. Biol. Chem. 259, 5734-5739; Carmen, G. M., Deems, R. A., and Dennis, E. A. (1995) J. Biol. Chem. 270, 18711-18714). Our results show that both PLC delta1 and E54K bind phosphatidylinositol bisphosphate cooperatively (Hill coefficients, n = 2.2 +/- 0.2 and 2.0 +/- 0.1, respectively). However, E54K shows a dramatically increased rate of (PI(4, 5)P2)-stimulated PI(4,5)P2 hydrolysis (interfacial Vmax for PLC delta1 = 4.9 +/- 0.3 micromol/min/mg and for E54K = 31 +/- 3 micromol/min/mg) as well as PI hydrolysis (Vmax for PLC delta1 = 27 +/- 3.4 nmol/min/mg and for E54K = 95 +/- 12 nmol/min/mg). In the absence of PI(4,5)P2 both native and mutant enzyme hydrolyze PI at similar rates. E54K also has a higher affinity for micellar substrate (equilibrium dissociation constant, Ks = 85 +/- 36 microM for E54K and 210 +/- 48 microM for PLC delta1). Centrifugation binding assays using large unilamelar phospholipid vesicles confirm that E54K binds PI(4,5)P2 with higher affinity than native enzyme. E54K is more active even though the interfacial Michaelis constant (Km) for E54K (0.034 +/- 0.01 mol fraction PI(4,5)P2) is higher than the Km for native enzyme (0.012 +/- 0.002 mol fraction PI(4,5)P2). D-Inositol trisphosphate is less potent at inhibiting E54K PI(4,5)P2 hydrolysis compared with native enzyme. These results demonstrate that a single amino acid substitution in the PH domain of PLC delta1 can dramatically enhance enzyme activity. Additionally, the marked increase in Vmax for E54K argues for a direct role of PH domains in regulating catalysis by allosteric modulation of enzyme structure.Peer reviewe

    Accelerating restrictive cardiomyopathy after liver transplantation in a patient with familial amyloidotic polyneuropathy: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Hereditary amyloidodis is a rare disease process with a propensity to cause polyneuropathies, autonomic dysfunction, and restrictive cardiomyopathy. It is transmitted in an autosomal dominant manner, with disease onset usually in the 20s-40s. The most common hereditary amyloidogenic protein, transthyretin, is synthesized in the liver and lies on Chromosome 18. Over 80 amyloidogenic transthyretin mutations have been described, the majority of which are neuropathic and hence the common name, Familial Amyloidotic Polyneuropathy. Until 1990, the disease was intractable with a 5–15 year survival after diagnosis. The prognosis changed after the implementation of orthotropic liver transplantation as a treatment strategy which halts the synthesis of amyloidogenic transthyretin. This has now has been performed over 1300 times in 67 centers.</p> <p>Case presentation</p> <p>We describe the case of a man of Irish ancestry with Familial Amyloidotic Polyneuropathy and no clinical history of cardiac involvement. Shortly after orthotropic liver transplantation, he developed congestive heart failure. He was subsequently diagnosed with an accelerating post-transplant restrictive cardiomyopathy due to amyloid infiltration.</p> <p>Conclusion</p> <p>A liver transplant induced cardiomyopathy in Familial Amyloidotic Polyneuropathy can be observed in patients without any history of cardiac symptoms. All patients with Familial Amyloidotic Polyneuropathy should be followed after transplantation to assess for a deterioration in cardiac function.</p

    Body Composition, Serum Biomarkers of Inflammation and Quality of Life in Clinically Stable Women with Estrogen Receptor Positive Metastatic Breast Cancer

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    Limited data exist regarding body composition and associated patient-reported outcomes for women with metastatic BC. Demographic, clinical, blood, and questionnaire data were collected to quantify body composition and explore associations with symptoms, inflammation, and quality of life (QOL) in 41 women with ER + metastatic BC. Diagnostic/surveillance computed tomography (CT) images including the third lumbar region (L3) were obtained to evaluate skeletal muscle (SM) quantity and quality, and abdominal adipose tissue. Frequencies, medians and interquartile ranges are presented, stratified by sarcopenia and obesity (Body mass index (BMI) ≥ 30.0 kg/m2). Overall, 34% (n = 14/41), 49% (n = 20/41), and 34% (n = 14) of women had sarcopenia, myosteatosis, and obesity, respectively. Handgrip strength was compromised in 24% of subjects (n = 10/41). Women with sarcopenia had significantly lower body weight (P = 0.01), BMI (P ≤ 0.001), and whole body SM (P \u3c 0.001), yet reported greater engagement in leisure time exercises (P = 0.05) vs. nonsarcopenic women. Women with obesity had significantly higher levels of abdominal obesity (all values P \u3c 0.0001) and serum biomarkers of inflammation (P values \u3c0.06), yet lower QOL (P = 0.02) vs. women without obesity. The abPGSGA did not differentiate women with sarcopenia. Future interventions should test if improvements in body composition are associated with better outcomes for this vulnerable, emerging population

    Characterization of a canola C2 domain gene that interacts with PG, an effector of the necrotrophic fungus Sclerotinia sclerotiorum

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    Sspg1d, one of endopolygalacturonases, is an important fungal effector secreted by the necrotrophic fungus Sclerotinia sclerotiorum during early infection. Using sspg1d as bait, a small C2 domain protein (designated as IPG-1) was identified by yeast two-hybrid screening of a canola cDNA library. Deletion analysis confirmed that the C-terminus of IPG-1 is responsible for its interaction with sspg1d in the yeast two-hybrid assay. The sspg1d/IPG-1 interaction was further confirmed in plant cells by a biomolecular fluorescence complementation (BiFC) assay. A transient expression assay showed that the IPG-1–GFP fusion protein was targeted to the plasma membrane and nucleus in onion epidermal cells. Following treatment with a Ca2+ ionophore, it was distributed throughout the cytosol. Real-time PCR assay demonstrated that IPG-1 was highly induced by Sclerotinia sclerotiorum in canola leaves and stems. Southern blot analysis indicated the presence of about five homologues of IPG-1 in the canola genome. Two additional members of the IPG-1gene family were isolated by RT-PCR. Their sequence similarity with IPG-1 is as high as 95%. However, they did not interact with sspg1d in the yeast two-hybrid assay. Possible roles of IPG-1 and its association with sspg1d in the defence signalling pathway were discussed

    Erythrocyte G Protein as a Novel Target for Malarial Chemotherapy

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    BACKGROUND: Malaria remains a serious health problem because resistance develops to all currently used drugs when their parasite targets mutate. Novel antimalarial drug targets are urgently needed to reduce global morbidity and mortality. Our prior results suggested that inhibiting erythrocyte G(s) signaling blocked invasion by the human malaria parasite Plasmodium falciparum. METHODS AND FINDINGS: We investigated the erythrocyte guanine nucleotide regulatory protein G(s) as a novel antimalarial target. Erythrocyte “ghosts” loaded with a G(s) peptide designed to block G(s) interaction with its receptors, were blocked in β-adrenergic agonist-induced signaling. This finding directly demonstrates that erythrocyte G(s) is functional and that propranolol, an antagonist of G protein–coupled β-adrenergic receptors, dampens G(s) activity in erythrocytes. We subsequently used the ghost system to directly link inhibition of host G(s) to parasite entry. In addition, we discovered that ghosts loaded with the peptide were inhibited in intracellular parasite maturation. Propranolol also inhibited blood-stage parasite growth, as did other β(2)-antagonists. β-blocker growth inhibition appeared to be due to delay in the terminal schizont stage. When used in combination with existing antimalarials in cell culture, propranolol reduced the 50% and 90% inhibitory concentrations for existing drugs against P. falciparum by 5- to 10-fold and was also effective in reducing drug dose in animal models of infection. CONCLUSIONS: Together these data establish that, in addition to invasion, erythrocyte G protein signaling is needed for intracellular parasite proliferation and thus may present a novel antimalarial target. The results provide proof of the concept that erythrocyte G(s) antagonism offers a novel strategy to fight infection and that it has potential to be used to develop combination therapies with existing antimalarials
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