Loss of connexin40 is associated with decreased endothelium-dependent relaxations and eNOS levels in the mouse aorta.

Upon agonist stimulation, endothelial cells trigger smooth muscle relaxation through the release of relaxing factors such as nitric oxide (NO). Endothelial cells of mouse aorta are interconnected by gap junctions made of connexin40 (Cx40) and connexin37 (Cx37), allowing the exchange of signaling molecules to coordinate their activity. Wild-type (Cx40(+/+)) and hypertensive Cx40-deficient mice (Cx40(-/-)), which also exhibit a marked decrease of Cx37 in the endothelium, were used to investigate the link between the expression of endothelial connexins (Cx40 and Cx37) and endothelial nitric oxide synthase (eNOS) expression and function in the mouse aorta. With the use of isometric tension measurements in aortic rings precontracted with U-46619, a stable thromboxane A(2) mimetic, we first demonstrate that ACh- and ATP-induced endothelium-dependent relaxations solely depend on NO release in both Cx40(+/+) and Cx40(-/-) mice, but are markedly weaker in Cx40(-/-) mice. Consistently, both basal and ACh- or ATP-induced NO production were decreased in the aorta of Cx40(-/-) mice. Altered relaxations and NO release from aorta of Cx40(-/-) mice were associated with lower expression levels of eNOS in the aortic endothelium of Cx40(-/-) mice. Using immunoprecipitation and in situ ligation assay, we further demonstrate that eNOS, Cx40, and Cx37 tightly interact with each other at intercellular junctions in the aortic endothelium of Cx40(+/+) mice, suggesting that the absence of Cx40 in association with altered Cx37 levels in endothelial cells from Cx40(-/-) mice participate to the decreased levels of eNOS. Altogether, our data suggest that the endothelial connexins may participate in the control of eNOS expression levels and function.

Dihydroaeruginoic acid synthetase and pyochelin synthetase, products of the pchEF genes, are induced by extracellular pyochelin in Pseudomonas aeruginosa.

The siderophore pyochelin of Pseudomonas aeruginosa is derived from one molecule of salicylate and two molecules of cysteine. Two cotranscribed genes, pchEF, encoding peptide synthetases have been identified and characterized. pchE was required for the conversion of salicylate to dihydroaeruginoate (Dha), the condensation product of salicylate and one cysteine residue and pchF was essential for the synthesis of pyochelin from Dha. The deduced PchE (156 kDa) and PchF (197 kDa) proteins had adenylation, thiolation and condensation/cyclization motifs arranged as modules which are typical of those peptide synthetases forming thiazoline rings. The pchEF genes were coregulated with the pchDCBA operon, which provides enzymes for the synthesis (PchBA) and activation (PchD) of salicylate as well as a putative thioesterase (PchC). Expression of a translational pchE'-'lacZ fusion was strictly dependent on the PchR regulator and was induced by extracellular pyochelin, the end product of the pathway. Iron replete conditions led to Fur (ferric uptake regulator)-dependent repression of the pchE'-'lacZ fusion. A translational pchD'-'lacZ fusion was also positively regulated by PchR and pyochelin and repressed by Fur and iron. Thus, autoinduction by pyochelin (or ferric pyochelin) and repression by iron ensure a sensitive control of the pyochelin pathway in P. aeruginosa.

Active mitral ring for post-surgical remote correction of residual mitral regurgitation on the beating heart.

OBJECTIVES: Residual mitral regurgitation after valve repair worsens patients' clinical outcome. Postimplant adjustable mitral rings potentially address this issue, allowing the reshaping of the annulus on the beating heart under echocardiography control. We developed an original mitral ring allowing valve geometry remodelling after the implantation and designed an animal study to assess device effectiveness in correcting residual mitral regurgitation. METHODS: The device consists of two concentric rings: one internal and flexible, sutured to the mitral annulus and a second external and rigid. A third conic element slides between the two rings, modifying the shape of the flexible ring. This sliding element is remotely activated with a rotating tool. Animal model: in adult swine, under cardio pulmonary bypass and cardiac arrest, we shortened the primary chordae of P2 segment to reproduce Type III regurgitation and implanted the active ring. We used intracardiac ultrasound to assess mitral regurgitation and the efficacy of the active ring to correct it. RESULTS: Severe mitral regurgitation (3+ and 4+) was induced in eight animals, 54 ± 6 kg in weight. Vena contracta width decreased from 0.8 ± 0.2 to 0.1 cm; proximal isovelocity surface area radius decreased from 0.8 ± 0.2 to 0.1 cm and effective regurgitant orifice area decreased from 0.50 ± 0.1 to 0.1 ± 0.1 cm(2). Six animals had a reversal of systolic pulmonary flow that normalized following the activation of the device. All corrections were reversible. CONCLUSIONS: Postimplant adjustable mitral ring corrects severe mitral regurgitation through the reversible modification of the annulus geometry on the beating heart. It addresses the frequent and morbid issue of recurrent mitral valve regurgitation.

Traduir la Terra Mitjana: la traducció de referents culturals i jocs de paraules en "El Senyor dels anells"

RESUM: En aquest treball de recerca s’han analitzat els referents culturals i els jocs de paraules que apareixen en l’obra El senyor dels anells. Com a reflexió inicial em baso en la hipòtesi que la caracterització de hòbbits, ents i homes, tres races que apareixen en la Terra Mitjana, el món secundari creat per Tolkien, es nodreix, a banda d’altres elements, de jocs de paraules i referents culturals britànics. És fonamental que aquesta afirmació sigui tinguda en compte en l’acte de traducció per respectar la intenció de J. R. R. Tolkien, que en aquesta obra buscava també la creació d’una mitologia britànica versemblant, com si de veritat la Terra Mitjana hagués constituït el passat real del nostre planeta amb els avantpassats britànics com a protagonistes. La composició d’aquest estudi es divideix en: (1) característiques de la literatura fantàstica; (2) aspectes relacionats amb l’autor des de dues vessants: l’una com a acadèmic i l’altra com a escriptor i creador; (3) teoria de la traducció de referents culturals i de jocs de paraules; i (4) corpus de 144 termes extrets del text de sortida analitzats i traduïts a partir de fitxes de traducció. Puc concloure que s’ha demostrat la hipòtesi que em plantejava: els referents culturals i els jocs de paraules són recursos actius en El senyor dels anells i una bona anàlisi d’aquests camps és pertinent per comprendre la magnitud de l’imaginari de J. R. R. Tolkien i realitzar una traducció respectuosa amb la intencionalitat de l’autor. El senyor dels anells és una fairy-story, una obra de fantasia, una fugida de la realitat consensuada (Tolkien no s’amaga d’aquesta fugida i la veu positiva) en què els elements propis del món primari (la cultura britànica i comunitats antigues com l’anglosaxona, la celta o l’escandinava) i del món secundari (els personatges que habiten la Terra Mitjana en el marc temporal de la Tercera Edat) funcionen d’acord amb els principis dels dos móns. Considero que el procés seguit tant en la metodologia, com en l’elaboració dels continguts, com en la traducció dels termes analitzats a través de les fitxes és positiu i útil. Aquesta sistematització del procés i el resultat final poden ser rellevants per a la comunitat traductora, tant per al futur traductor com per al professional.

Ocular distribution, spectrum of activity, and in vivo viral neutralization of a fully humanized anti-herpes simplex virus IgG Fab fragment following topical application.

Herpes simplex ocular infection is a major cause of corneal blindness. Local antiviral treatments exist but are associated with corneal toxicity, and resistance has become an issue. We evaluated the biodistribution and efficacy of a humanized anti-herpes simplex virus (anti-HSV) IgG FAb fragment (AC-8; 53 kDa) following repeated topical administration. AC-8 was found in the corneal epithelium, anterior stroma, subepithelial stromal cells, and retinal glial cells, with preferential entry through the ocular limbus. AC-8 was active against 13 different strains of HSV-1, with 50% and 90% mean effective concentrations (MEC(50) and MEC(90), respectively) ranging from 0.03 to 0.13 μg/ml, indicating broad-spectrum activity. The in vivo efficacy of AC-8 was evaluated in a mouse model of herpes-induced ocular disease. Treatment with low-dose AC-8 (1 mg/ml) slightly reduced the ocular disease scores. A greater reduction of the disease scores was observed in the 10-mg/ml AC-8-treated group, but not as much as with trifluridine (TFT). AC-8 treatment reduced viral titers but less than trifluridine. AC-8 did not display any toxicity to the cornea or other structures in the eye. In summary, topical instillation of an anti-HSV FAb can be used on both intact and ulcerated corneas. It is well tolerated and does not alter reepithelialization. Further studies to improve the antiviral effect are needed for AC-8 to be considered for therapeutic use.

Urinary sphincter based on electronics and artificial muscles

Objectives: The AMS 800TM is the current artificial urinary sphincter (AUS) for incontinence due to intrinsic sphincter deficiency. Despite good clinical results, technical failures inherent to the hydraulic mechanism or urethral ischemic injury contribute to revisions up to 60%. We are developing an electronic AUS, called ARTUS to overcome the rigors of AMS. The objective of this study was to evaluate the technical efficacy and tissue tolerance of the ARTUS system in an animal model.Methods: The ARTUS is composed by three parts: the contractile unit, a series of rings and an integrated microprocessor. The contractile unit is made of Nitinol fibers. The rings are placed around the urethra to control the flow of urine by squeezing the urethra. They work in a sequential alternative mode and are controlled by a microprocessor. In the first phase a three-rings device was used while in the second phase a two-rings ARTUS was used. The device was implanted in 14 sheep divided in two groups of six and eight animals for study purpose. The first group aimed at bladder leak point pressure (BLPP) measurement and validation of the animal model; the second group aimed at verifying mid-term tissue tolerance by explants at twelve weeks. General animal tolerance was also evaluated.Results: The ARTUS system implantation was uneventful. When the system was activated, the BLPP was measured at 1.038±0.044 bar (mean±SD). Urethral tissue analysis did not show significant morphological changes. No infection and no sign of discomfort were noted in animals at 12 weeks.Conclusions: The ARTUS proved to be effective in continence achievement in this study. Histological results support our idea that a sequential alternative mode can avoid urethral atrophy and ischemia. Further technical developments are needed to verify long-term outcome and permit human use.

Rapidly fatal poisoning with an insecticide containing rotenone.

Introduction: Rotenone is a botanical pesticide derived from extracts of Derris roots, which is traditionally used as piscicide, but also as an industrial insecticide for home gardens. Its mechanism of action is potent inhibition of mitochondrial respiratory chain by uncoupling oxidative phosphorylation by blocking electron transport at complex-I. Despite its classification as mild to moderately toxic to humans (estimated LD50, 300-500 mg/kg), there is a striking variety of acute toxicity of rotenone depending on the formulation (solvents). Human fatalities with rotenone-containing insecticides have been rarely reported, and a rapid deterioration within a few hours of the ingestion has been described previously in one case. Case report: A 49-year-old Tamil man with a history of asthma, ingested 250 mL of an insecticide containing 1.24% of rotenone (3.125 g, 52.1-62.5 mg/kg) in a suicide attempt at home. The product was not labeled as toxic. One hour later, he vomited repeatedly and emergency services were alerted. He was found unconscious with irregular respiration and was intubated. On arrival at the emergency department, he was comatose (GCS 3) with fixed and dilated pupils, and absent corneal reflexes. Physical examination revealed hemodynamic instability with hypotension (55/30 mmHg) and bradycardia (52 bpm). Significant laboratory findings were lactic acidosis (pH 6.97, lactate 17 mmol/L) and hypokalemia (2 mmol/L). Cranial computed tomography (CT) showed early cerebral edema. A single dose of activated charcoal was given. Intravenous hydration, ephedrine, repeated boli of dobutamine, and a perfusor with 90 micrograms/h norepinephine stabilized blood pressure temporarily. Atropine had a minimal effect on heart rate (58 bpm). Intravenous lipid emulsion was considered (log Pow 4.1), but there was a rapid deterioration with refractory hypotension and acute circulatory failure. The patient died 5h after ingestion of the insecticide. No autopsy was performed. Quantitative analysis of serum performed by high-resolution/accurate mass-mass spectrometry and liquid chromatography (LC-HR/AM-MS): 560 ng/mL rotenone. Other substances were excluded by gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS/MS). Conclusion: The clinical course was characterized by early severe symptoms and a rapidly fatal evolution, compatible with inhibition of mitochondrial energy supply. Although rotenone is classified as mild to moderately toxic, physicians must be aware that suicidal ingestion of emulsified concentrates may be rapidly fatal. (n=3): stridor, cyanosis, cough (one each). Local swelling after chewing or swallowing soap developed at the earliest after 20 minutes and persisted beyond 24 hours in some cases. Treatment with antihistamines and/or steroids relieved the symptoms in 9 cases. Conclusion: Bar soap ingestion by seniors carries a risk of severe local reactions. Half the patients developed symptoms, predominantly swellings of tongue and/or lips (38%). Cognitive impairment, particularly in the cases of dementia (37%), may increase the risk of unintentional ingestion. Chewing and intraoral retention of soap leads to prolonged contact with the mucosal membranes. Age-associated physiological changes of oral mucosa probably promote the irritant effects of the surfactants. Medical treatment with antihistamines and corticosteroids usually leads to rapid decline of symptoms. Without treatment, there may be a risk of airway obstruction.

Fenilefrina intracamerular en el síndrome del iris flácido intraoperatorio

La incidència d’hipertròfia benigna de pròstata és aproximadament d’un 50 % en pacients majors de 50 anys. La Tamsulosina és el medicament més prescrit per aquesta dolència i la principal causa del síndrome d’iris flàccid intraoperatori a la cirurgia de cataractes. Els nostres dos estudis han sigut; per una banda, avaluar la toxicitat corneal i afectació cardíaca de Fenilefrina intracamerular a una concentració de 2,5% respecte la pauta de dilatació tòpica estàndard al nostre centre, i per l’altra, comparar l’ efectivitat i diferència al recompte endotelial de Fenilefrina intracamerular a una concentració de 2,5% respecte a una altra concentració del 1,66 %, mesurant els seus efectes en diverses variables.

Recidiva de distrofias estromales corneales tras queratoplastia

Objectiu: valorar l'índex de recidiva simple o recidiva clínicament significativa dels diferents tipus de distròfies estromals anteriors en empelts corneals després cirurgia de queratoplàstia. Material i mètodes: S'ha realitzat una revisió retrospectiva del 1954 al 2008 al Centre d'Oftalmologia Barraquer, identificant a tots els pacients diagnosticats de distròfia corneal estromal anterior i de la membrana de Bowman (Distròfia de Reis Bücklers, Distròfia Granular, Distròfia reticular, distròfia macular) que han estat intervinguts de queratoplàstia penetrant (QP) o queratoplàstia laminar (QL). S'han utilitzat estadístics descriptius i la funció de supervivència amb les corbes de Kaplan Meier per dur a terme l'anàlisi de la mostra. Resultats: La mostra total del nostre estudi ha estat de 109 ulls de 66 pacients amb distròfies estromals anteriors operats de queratoplàstia: 8 casos de distròfies de la capa de Bowman (6 ulls amb CDRB o CDB-I (distròfia de Reis Bücklers), i 2 ulls amb CDTB o CDB-I (distròfia de Thiel Behnke)), 19 casos de distròfies granulars (CDG), 53 casos de distròfia de lattice (CDL) i 29 casos de distròfia macular (CDM). Amb un llarg de temps de seguiment (75-180 mesos de mitjana), la recurrència simple ha estat del 33% dels casos de CDRB amb 46 mesos de temps mitjà de supervivència, del 58, 8% dels casos de CDG amb 74.6 mesos de supervivència, el 41'5% de les CDL amb 106 mesos de supervivència i en el 10% dels casos amb CDM amb 96 mesos de temps mitjà de supervivència. La recurrència clínicament significativa es va manifestar en la seva majoria en els casos de CDL i CDG amb un temps mitjà de supervivència de 127.6 mesos i 124.1 mesos respectivament. El símptoma principal d'aquestes manifestacions clíniques va ser la disminució de la AV. Conclusió: La queratoplàstia penetrant és un tractament clàssic eficaç per als casos de distròfies estromals anteriors simptomàtics, amb opacitats profundes en l'estroma o fracàs previ d'altres teràpies menys invasives com la PTK. Com és d'esperar, per la seva origen genètic, l'aparició de recurrència de la distròfia després del trasplantament existeix i s'incrementa amb el major temps de seguiment. La tendència d'aquesta recidiva és a presentar inicialment en el pla cornial epitelial i requereix un llarg temps d'evolució per fer-se simptomàtica, especialment en els casos de CDG, CDL i CDM.

Estudio comparativo entre microscopía confocal y microscopía especular en la valoración del endotelio en córneas con distrofia de Fuchs

La distròfia endotelial de Fuchs es caracteritza per la formació de guttas endotelials i en estadis avançats pot induir edema corneal i pèrdua d’agudesa visual. A diferència del microscopi especular, el microscopi confocal té un disseny que permet evitar la llum aberrant causada per l’edema corneal o opacitats estromals. Comparant ambdues probes en la valoració de l’endoteli corneal en pacients amb distròfia de Fuchs, s’observa millor qualitat d’imatge per microscòpia confocal tot i que no es podia valorar la fiabilitat de l’esmentada proba en la determinació de la densitat cel•lular endotelial en les còrnies afectades.

Kératite varicelleuse séquellaire [Followup of chicken pox keratitis. Anatomic-clinical case report].

Chicken pox is a very common infectious disease in children. Its corneal involvement is less serious than with measles, which may lead to blindness in numerous developing countries. However, with occasional cases occur. A case of a 59-year-old male patient whose left cornea was involved during a chicken pox infection at the age of 7 is reported. More recently, the vision of the right eye was normal at 20/20 and reduced to visual perception in the affected left eye. Corneal sensitivity was maintained in the left eye, which, however exhibited a central epithelial defect. A central round opacity of the left corneal stroma was believed to be the scar resulting from a previous disciform keratitis. The left central cornea was thinned and there was neither an anterior chamber flare nor new corneal vessels. This corneal condition required a corneal allograft, performed quickly because of the potential risk of perforation. Histopathological study of the corneal button showed a central corneal thinning with an increase in epithelial thickness. The corneal stroma was disorganized, with irregular collagen bundles. No inflammatory cells could be observed, however. All the histopathological changes observed were those of a corneal scar.

Hypoxic contraction of small pulmonary arteries from normal and endotoxemic rats: fundamental role of NO.

The present study was aimed at examining the role of nitric oxide (NO) in the hypoxic contraction of isolated small pulmonary arteries (SPA) in the rat. Animals were treated with either saline (sham experiments) or Escherichia coli lipolysaccharide [LPS, to obtain expression of the inducible NO synthase (iNOS) in the lung] and killed 4 h later. SPA (300- to 600-micrometer outer diameter) were mounted as rings in organ chambers for the recording of isometric tension, precontracted with PGF2alpha, and exposed to either severe (bath PO2 8 +/- 3 mmHg) or milder (21 +/- 3 mmHg) hypoxia. In SPA from sham-treated rats, contractions elicited by severe hypoxia were completely suppressed by either endothelium removal or preincubation with an NOS inhibitor [NG-nitro-L-arginine methyl ester (L-NAME), 10(-3) M]. In SPA from LPS-treated rats, contractions elicited by severe hypoxia occurred irrespective of the presence or absence of endothelium and were largely suppressed by L-NAME. The milder hypoxia elicited no increase in vascular tone. These results indicate an essential role of NO in the hypoxic contractions of precontracted rat SPA. The endothelium independence of HPV in arteries from LPS-treated animals appears related to the extraendothelial expression of iNOS. The severe degree of hypoxia required to elicit any contraction is consistent with a mechanism of reduced NO production caused by a limited availability of O2 as a substrate for NOS.

The nature of the Cr-C bond: direct estimation of aromaticity in Fischer carbenes

Report for the scientific sojourn at the the Philipps-Universität Marburg, Germany, from september to december 2007. For the first, we employed the Energy-Decomposition Analysis (EDA) to investigate aromaticity on Fischer carbenes as it is related through all the reaction mechanisms studied in my PhD thesis. This powerful tool, compared with other well-known aromaticity indices in the literature like NICS, is useful not only for quantitative results but also to measure the degree of conjugation or hyperconjugation in molecules. Our results showed for the annelated benzenoid systems studied here, that electron density is more concentrated on the outer rings than in the central one. The strain-induced bond localization plays a major role as a driven force to keep the more substituted ring as the less aromatic. The discussion presented in this work was contrasted at different levels of theory to calibrate the method and ensure the consistency of our results. We think these conclusions can also be extended to arene chemistry for explaining aromaticity and regioselectivity reactions found in those systems.In the second work, we have employed the Turbomole program package and density-functionals of the best performance in the state of art, to explore reaction mechanisms in the noble gas chemistry. Particularly, we were interested in compounds of the form H--Ng--Ng--F (where Ng (Noble Gas) = Ar, Kr and Xe) and we investigated the relative stability of these species. Our quantum chemical calculations predict that the dixenon compound HXeXeF has an activation barrier for decomposition of 11 kcal/mol which should be large enough to identify the molecule in a low-temperature matrix. The other noble gases present lower activation barriers and therefore are more labile and difficult to be observable systems experimentally.

An ocellar "pupil" that does not change with light intensity, but with the insect age in Triatoma infestans

The simple eyes (ocelli) of recently emerged adult Triatoma infestans exhibit a narrow elongated "pupil", surrounded by a ring of brown-reddish pigment, the "iris". This pupil does not respond to changes in the illumination, but varies in size after the imaginal ecdysis. This change corresponds, internally, with the growth of the corneal lens and the associated retina up to an age of about 20 days. This has not been previously observed in an insect. The use of this characteristic for recognising young adults of this species is suggested.

TGFBI (BIGH3) gene mutations in German families: two novel mutations associated with unique clinical and histopathological findings.

BACKGROUND: To report the clinical, histopathological and immunohistochemical findings of two novel mutations within the TGFBI gene. METHODS: The genotype of 41 affected members of 16 families and nine sporadic cases was investigated by direct sequencing of the TGFBI gene. Clinical, histological and immunohistochemical characteristics of corneal opacification were reported and compared with the coding region changes in the TGFBI gene. RESULTS: A novel mutation Leu509Pro was detected in one family with a geographic pattern-like clinical phenotype. Histopathologically we found amyloid together with non-amyloid deposits and immunohistochemical staining of Keratoepithelin (KE) KE2 and KE15 antibodies. In two families and one sporadic case the novel mutation Gly623Arg with a late-onset, map-like corneal dystrophy was identified. Here amyloid and immunohistochemical staining of only KE2 antibodies occurred. Further, five already known mutations are reported: Arg124Cys Arg555Trp Arg124His His626Arg, Ala546Asp in 13 families and five sporadic cases of German origin. The underlying gene defect within the TBFBI gene was not identified in any of the four probands with Thiel-Behnke corneal dystrophy. CONCLUSIONS: The two novel mutations within the TGFBI gene add another two phenotypes with atypical immunohistochemical and histopathological features to those so far reported.