Revue Generale Sur Les Rhinolithiases : A Propos De 20 Cas

Cette étude rapporte 20 cas de rhinolithiases colligés entre 1990 et 2007. La population concernée surtout des adultes (55% de sexe féminin) ayant le plus souvent des conditions socio-économiques défavorables. Le tableau clinique est simple et non spécifique : rhinite obstructive purulente unilatérale et fétide. Des présentations déroutantes sont possibles mais rares (infection sinusienne, oculo-palpébrale). Le diagnostic repose sur l'examen endonasal notamment à l'optique rigide. Le scanner est très intéressant pour un bon bilan loco-régional permettant en particulier de reconnaître les lésions associées ou sous-jacentes. L'extraction par les voies naturelles le plus souvent sous anesthésie locale était le procédé thérapeutique habituel. Les rhinolithes avaient entre 5 et 50 mm de diamètre avec seulement 3 corps étranger associés (15 %). Les complications sont rares (épistaxis : 10%) et l'évolution était le plus souvent favorable.This study reports 20 cases of rhinolithiasis treated between 1990 and 2007. The population concerns especially adults. The symptoms are generally represented by unilateral purulent rhinorrhea and nasal obstruction. The diagnosis is based on clinical examination. The CT-scan precises extension and associated or underlying lesions. The extraction by natural ways, often under local anesthesia, was proceeded as habitual therapeutic. The rhinoliths had between 5 and 50 mm of diameter with only 3 foreign bodies associated (15%). The complications are rare (nasal bleeding: 10%). Keywords: Rhinolithiasis, nasa foreign body, purulent rhinorrhea. Journal Tunisien d'ORL et de chirurgie cervico-faciale Vol. 18 2007: pp. 34-3

Role of homologous ASP334 and GLU319 in human non-gastric H,K- and Na,K-ATPases in cardiac glycoside binding

Cardiac steroids inhibit Na,K-ATPase and the related non-gastric H,K-ATPase, while they do not interact with gastric H,K-ATPase. Introducing an arginine, the residue present in the gastric H,K-ATPase, in the second extracellular loop at the corresponding position 334 in the human non-gastric H,K-ATPase (D334R mutation) rendered it completely resistant to 2mM ouabain. The corresponding mutation (E319R) in alpha1 Na,K-ATPase produced a approximately 2-fold increase of the ouabain IC(50) in the ouabain-resistant rat alpha1 Na,K-ATPase and a large decrease of the ouabain affinity of human alpha1 Na,K-ATPase, on the other hand this mutation had no effect on the affinity for the aglycone ouabagenin. These results provide a strong support for the orientation of ouabain in its biding site with its sugar moiety interacting directly with the second extracellular loop

Prognosis of Transthyretin Cardiac Amyloidosis Without Heart Failure Symptoms.

BACKGROUND Transthyretin amyloid cardiomyopathy (ATTR-CM) is increasingly recognized as a treatable cause of heart failure (HF). Advances in diagnosis and therapy have increased the number of patients diagnosed at early stages, but prognostic data on patients without HF symptoms are lacking. Moreover, it is unknown whether asymptomatic patients benefit from early initiation of transthyretin (TTR) stabilizers. OBJECTIVES The aim of this study was to describe the natural history and prognosis of ATTR-CM in patients without HF symptoms. METHODS Clinical characteristics and outcomes of patients with ATTR-CM without HF symptoms were retrospectively collected at 6 international amyloidosis centers. RESULTS A total of 118 patients (78.8% men, median age 66 years [IQR: 53.8-75 years], 68 [57.6%] with variant transthyretin amyloidosis, mean left ventricular ejection fraction 60.5% ± 9.9%, mean left ventricular wall thickness 15.4 ± 3.1 mm, and 53 [45%] treated with TTR stabilizers at baseline or during follow-up) were included. During a median follow-up period of 3.7 years (IQR: 1-6 years), 38 patients developed HF symptoms (23 New York Heart Association functional class II and 14 functional class III or IV), 32 died, and 2 required cardiac transplantation. Additionally, 20 patients received pacemakers, 13 developed AF, and 1 had a stroke. Overall survival was 96.5% (95% CI: 91%-99%), 90.4% (95% CI: 82%-95%), and 82% (95% CI: 71%-89%) at 1, 3, and 5 years, respectively. Treatment with TTR stabilizers was associated with improved survival (HR: 0.31; 95% CI: 0.12-0.82; P = 0.019) and remained significant after adjusting for sex, age, ATTR-CM type, and estimated glomerular filtration rate (HR: 0.18; 95% CI: 0.06-0.55; P = 0.002). CONCLUSIONS After a median follow-up period of 3.7 years, 1 in 3 patients with asymptomatic ATTR-CM developed HF symptoms, and nearly as many died or required cardiac transplantation. Treatment with TTR stabilizers was associated with improved prognosis.This work was supported by grants from Instituto de Salud Carlos III (PI18/0765 and PI20/01379). Dr Gonzalez-Lopez has received speaker fees from Pfizer and Alnylam; has received consulting fees from Pfizer and Proclara; and has received research and educational support to her institution from Pfizer, BridgeBio, and Alnylam. Dr Obici has received speaker and consulting fees from Pfizer, Alnylam, and Akcea. Dr AbouEzzeddine has received research grant support from Pfizer. Dr Mussinelli has received speaker fees from Pfizer and Akcea. Dr Dispenzieri has received consulting fees from Janssen and Akcea; and has received research support from Pfizer, Alnylam, Celgene, and Takeda. Dr Perlini has received speaker and consulting fees from Pfizer, Alnylam, and Akcea. Dr Palladini has received speaker fees from Janssen-Cilag, Pfizer, and Siemens; and has participated on an advisory board for Janssen Cilag. Dr Damy has received research grants or consulting fees from Alnylam, Akcea, Pfizer, and Prothena. Dr Grogan has received research grant support and consulting fees to her institution from Alnylam, Eidos, Pfizer, and Prothena. Dr Maurer has received grant support from National Institutes of Health (R01HL139671-01, R21AG058348, and K24AG036778); has received consulting income from Pfizer, GlaxoSmithKline, Eidos, Prothena, Akcea, and Alnylam; and has received clinical trial funding to his institution from Pfizer, Prothena, Eidos, and Alnylam. Dr Garcia-Pavia has received speaker fees from Pfizer, BridgeBio, Alnylam, and Ionis; has received consulting fees from Pfizer, BridgeBio, AstraZeneca, NovoNordisk, Neuroimmune, Alnylam, Alexion, and Attralus; and has received research and educational support to his institution from Pfizer, BridgeBio, and Alnylam. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.S

Reparation des pertes de substances partielles du pavillon de L\'oreille (Conque): a propos dune observation

No Abstract. Journal Tunisien d'ORL et de chirurgie cervico-faciale Vol. 17 2006: pp. 43-4

Pneumatisation du cornet inferieur a propos d\'une observation

No Abstract. Journal Tunisien d'ORL et de chirurgie cervico-faciale Vol. 17 2006: pp. 63-6

Functional differences between alpha subunit isoforms of the rat Na,K-ATPase expressed in Xenopus oocytes.

The functional properties of the three most widely distributed alpha subunit isoforms of the Na,K-ATPase are not well known, particularly concerning the voltage dependence of their activity and cation binding kinetics. We measured the electrogenic activity generated by Na,K-ATPases resulting from co-expression of the rat alpha1, alpha2* or alpha3* subunits with the rat beta1 subunit in Xenopus oocytes; alpha2* and alpha3* are ouabain-resistant mutants of the alpha2 and alpha3 isoform, which allowed selective inhibition of the endogenous Na(+),K(+)-pump of the oocyte. In oocytes expressing the three isoforms of the alpha subunit, K(+) induced robust outward currents that were largely ouabain-sensitive. In addition, ouabain-sensitive inward currents were recorded for all three isoforms in sodium-free and potassium-free acid solutions. The very similar voltage dependence of the Na(+),K(+)-pump activity observed in the absence of extracellular Na(+) indicated a similar stoichiometry of the transported cations by the three isoforms. The affinity for extracellular K(+) was slightly lower for the alpha2* and alpha3* than for the alpha1 isoform. The alpha2* isoform was, however, more sensitive to voltage-dependent inhibition by extracellular Na(+), indicating a higher affinity of the extracellular Na(+) site in this isoform. We measured and controlled [Na(+)](i) using a co-expressed amiloride-sensitive Na(+) channel. The intracellular affinity for Na(+) was slightly higher in the alpha2* than in the alpha1 or alpha3* isoforms. These results suggest that the alpha2 isoform could have an activity that is strongly dependent upon [Na(+)](o) and [K(+)](o). These concentrations could selectively modulate its activity when large variations are present, for instance in the narrow intercellular spaces of brain or muscle tissues

The fourth transmembrane segment of the Na,K-ATPase alpha subunit: a systematic mutagenesis study.

The Na,K-ATPase is a major ion-motive ATPase of the P-type family responsible for many aspects of cellular homeostasis. To determine the structure of the pathway for cations across the transmembrane portion of the Na,K-ATPase, we mutated 24 residues of the fourth transmembrane segment into cysteine and studied their function and accessibility by exposure to the sulfhydryl reagent 2-aminoethyl-methanethiosulfonate. Accessibility was also examined after treatment with palytoxin, which transforms the Na,K-pump into a cation channel. Of the 24 tested cysteine mutants, seven had no or a much reduced transport function. In particular cysteine mutants of the highly conserved "PEG" motif had a strongly reduced activity. However, most of the non-functional mutants could still be transformed by palytoxin as well as all of the functional mutants. Accessibility, determined as a 2-aminoethyl-methanethiosulfonate-induced reduction of the transport activity or as inhibition of the membrane conductance after palytoxin treatment, was observed for the following positions: Phe(323), Ile(322), Gly(326), Ala(330), Pro(333), Glu(334), and Gly(335). In accordance with a structural model of the Na,K-ATPase obtained by homology modeling with the two published structures of sarcoplasmic and endoplasmic reticulum calcium ATPase (Protein Data Bank codes 1EUL and 1IWO), the results suggest the presence of a cation pathway along the side of the fourth transmembrane segment that faces the space between transmembrane segments 5 and 6. The phenylalanine residue in position 323 has a critical position at the outer mouth of the cation pathway. The residues thought to form the cation binding site II ((333)PEGL) are also part of the accessible wall of the cation pathway opened by palytoxin through the Na,K-pump

Bufo marinus bladder H-K-ATPase carries out electroneutral ion transport

Bufo marinus bladder H-K-ATPase belongs to the Na-K-ATPase and H-K-ATPase subfamily of oligomeric P-type ATPases and is closely related to rat and human nongastric H-K-ATPases. It has been demonstrated that this ATPase transports K(+) into the cell in exchange for protons and sodium ions, but the stoichiometry of this cation exchange is not yet known. We studied the electrogenic properties of B. marinus bladder H-K-ATPase expressed in Xenopus laevis oocytes. In a HEPES-buffered solution, K(+) activation of the H-K-ATPase induced a slow-onset inward current that reached an amplitude of approximately 20 nA after 1-2 min. When measurements were performed in a solution containing 25 mM HCO at a PCO(2) of 40 Torr, the negative current activated by K(+) was reduced. In noninjected oocytes, intracellular alkalization activated an inward current similar to that due to B. marinus H-K-ATPase. We conclude that the transport activity of the nongastric B. marinus H-K-ATPase is not intrinsically electrogenic but that the inward current observed in oocytes expressing this ion pump is secondary to intracellular alkalization induced by proton transport

Electrogenicity of Na,K- and H,K-ATPase activity and presence of a positively charged amino acid in the fifth transmembrane segment.

The transport activity of the Na,K-ATPase (a 3 Na+ for 2 K+ ion exchange) is electrogenic, whereas the closely related gastric and non-gastric H,K-ATPases perform electroneutral cation exchange. We have studied the role of a highly conserved serine residue in the fifth transmembrane segment of the Na,K-ATPase, which is replaced with a lysine in all known H,K-ATPases. Ouabain-sensitive 86Rb uptake and K+-activated currents were measured in Xenopus oocytes expressing the Bufo bladder H,K-ATPase or the Bufo Na,K-ATPase in which these residues, Lys800 and Ser782, respectively, were mutated. Mutants K800A and K800E of the H,K-ATPase showed K+-stimulated and ouabain-sensitive electrogenic transport. In contrast, when the positive charge was conserved (K800R), no K+-induced outward current could be measured, even though rubidium transport activity was present. Conversely, the S782R mutant of the Na,K-ATPase had non-electrogenic transport activity, whereas the S782A mutant was electrogenic. The K800S mutant of the H,K-ATPase had a more complex behavior, with electrogenic transport only in the absence of extracellular Na+. Thus, a single positively charged residue in the fifth transmembrane segment of the alpha-subunit can determine the electrogenicity and therefore the stoichiometry of cation transport by these ATPases