38 research outputs found

    Method for detecting hyaluronan in isolated myenteric plexus ganglia of adult rat small intestine

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    The cellular components of the enteric nervous system (ENS), namely enteric neurons and glia, display plasticity and respond to environmental cues deriving from growth factors, extracellular matrix (ECM) molecules, and cell-surface molecules, both in physiological and pathological conditions. ECM, in particular, provides an important framework for the enteric microenvironment and influences the homeostasis of myenteric neuronal circuitries. Isolation of pure myenteric plexus preparations from adult tissue permits to investigate changes in the ENS involving specific ECM, such as hyaluronan. This approach is based upon the possibility to isolate myenteric ganglia from the intestinal wall of either adult animals or humans, after microdissection and subsequent enzymatic digestion of the tissue. Enteric ganglia are free of connective tissue, extracellular collagen, and blood vessels, and thus treatment of intact intestinal segments with highly purified collagenases permits ganglia isolation from the surrounding smooth muscle cells. In this chapter, we describe methods for visualizing HA in isolated primary cultures of adult rat small intestine myenteric ganglia

    Ductus venosus Doppler measurement during labor

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    Honey-sensitive Pseudomonas aeruginosa mutants are impaired in catalase A

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    The antimicrobial power of honey seems to be ascribable to several factors, including oxidative and osmotic stress. The aim of this study was to find genetic determinants involved in the response to honey stress in the opportunistic pathogen Pseudomonas aeruginosa, chosen as model micro-organism. A library of transposon mutants of P. aeruginosa PAO1 was constructed and only four mutants unable to grow in presence of fir honeydew honey were selected. All four mutants were impaired in the major H2O2-scavenging enzyme catalase A (KatA). The knockout of katA gene caused sensitivity, as expected, not only to hydrogen peroxide but also to different types of honey including Manuka GMO 220 honey. Genetic complementation, as well as the addition of PAO1 supernatant containing extracellular catalase, restored tolerance to honey stress in all the mutants. As P. aeruginosa PAO1 catalase KatA copes with H2O2 stress, it is conceivable that the antimicrobial activity of honey is, at least partially, due to the presence of hydrogen peroxide in honey or the ability of honey to induce production of hydrogen peroxide. The katA-deficient mutants could be used as tester micro-organisms to compare the power of different types of natural and curative honeys in eliciting oxidative stress mediated by hydrogen peroxide

    Screening for cervixcancer kan vara kostnadseffektiv. Kombinationen cellprov och HPV-test skulle ge ytterligare vinster.

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    En hälsoekonomisk utvärdering av cellprovsscreening för cervixcancer har saknats vad gäller svenska förhållanden. I en modellstudie jämfördes effekter av och kostnader för gynekologisk cellprovskontroll med och utan tillägg av test för humant papillomvirus (HPV). Med cellprovsscreening i åldern 32–60 år vart tredje till vart femte år minskar risken att insjukna i invasiv cervixcancer med 88 procent, och sjukvårdens kostnader halveras jämfört med att inte screena. Med tillägg av ett eller två HPV-test vid 32 års ålder och oförändrad screeningpolicy ökar kostnaderna, och inga hälsovinster kan påvisas. En screeningstrategi med cellprov i kombination med HPV-test vid enbart tre tillfällen i livet – vid 32, 41 och 50 års ålder – kostar mindre och ger, enligt modellen, hälsovinster jämfört med enbart cellprovsscreening i åldern 32–60 år

    Involvement of hyaluronan in the adaptive changes of the rat small intestine neuromuscular function after ischemia/reperfusion injury

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    Intestinal ischemia/reperfusion (I/R) injury has severe consequences on myenteric neurons, which can be irreversibly compromised resulting in slowing of transit and hindered food digestion. Myenteric neurons synthesize hyaluronan (HA) to form a well-structured perineuronal net, which undergoes derangement when myenteric ganglia homeostasis is perturbed, i.e. during inflammation. In this study we evaluated HA involvement in rat small intestine myenteric plexus after in vivo I/R injury induced by clamping a branch of the superior mesenteric artery for 60 min, followed by 24 h of reperfusion. In some experiments, 4-methylumbelliferone (4-MU, 25 mg/kg), a HA synthesis inhibitor, was intraperitoneally administered to normal (CTR), sham-operated (SH) and I/R animals for 24 h. In longitudinal muscle myenteric plexus (LMMP) whole-mount preparations, HA binding protein staining as well as HA levels were significantly higher in the I/R group, and were reduced after 4-MU treatment. HA synthase 1 and 2 (HAS1 and HAS2) labelled myenteric neurons and mRNA levels in LMMPs increased in the I/R group with respect to CTR, and were reduced by 4-MU. The efficiency of the gastrointestinal transit was significantly reduced in I/R and 4-MU-treated I/R groups with respect to CTR and SH groups. In the 4-MU-treated I/R group gastric emptying was reduced with respect to the CTR, SH and I/R groups. Carbachol (CCh) and electrical field (EFS, 0.1–40 Hz) stimulated contractions and EFS-induced (10 Hz) NANC relaxations were reduced in the I/R group with respect to both CTR and SH groups. After I/R, 4-MU treatment increased EFS contractions towards control values, but did not affect CCh-induced contractions. NANC on-relaxations after I/R were not influenced by 4-MU treatment. Main alterations in the neurochemical coding of both excitatory (tachykinergic) and inhibitory pathways (iNOS, VIPergic) were also observed after I/R, and were influenced by 4-MU administration. Overall, our data suggest that, after an intestinal I/R damage, changes of HA homeostasis in specific myenteric neuron populations may influence the efficiency of the gastrointestinal transit. We cannot exclude that modulation of HA synthesis in these conditions may ameliorate derangement of the enteric motor function preventing, at least in part, the development of dysmotility
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