1,721,161 research outputs found
Case report of asymptomatic peritoneal leimyomas.
No full textEur J Obstet Gynecol Reprod Biol. 2010 Feb;148(2):205-6. Epub 2009 Nov 5.
Case report of asymptomatic peritoneal leiomyomas.
Pezzuto A, Pontrelli G, Ceccaroni M, Ferrari B, Nardelli GB, Minelli L.
We would like to report the history of a fertile 45-year-old woman, referred for persistent metrorrhagia with sonographic evidence of multiple uterine myomas. An endometrial biopsy was performed and a normal endometrium was found from a histological point of view. In due time, she underwent laparoscopic-assisted vaginal hysterectomy with preservation of the ovaries. During surgery, evidence of several intramural fibroids was recorded along with two large pedunculated myomas. After colpotomy, two further myomas of 5 and 3 cm were identified as completely detached from the uterus. They appeared pedunculated (with their vascularization) to the perirectal peritoneum (Fig. 1). Therefore the two fibroids were removed and extracted through the vagina after diathermy coagulation of their vascular stems. From a histological point of view these fibroids were identical to a normal leiomyoma, consisting of fascicles of smooth muscle cells without mitotic figures or nuclear pleomorphism
Concentration wave of a solute in an artery: the influence of curvature
No full textMass transport and diffusion phenomena in the arterial lumen are studied through a mathematical model.
Blood flow is described by the unsteady Navier-Stokes equation and solute dynamics by an advection-diffusion equation, the convective field being provided by the fluid velocity.
A linearization procedure over the steady state solution is carried out and an asymptotic analysis is used to study the effect of a small curvature with respect to the straight tube.
Analytical and numerical solutions are found: the results show the characteristics of the long wave propagation and the role played by the geometry on the solute distribution and demonstrate the strong influence of curvature induced by the fluid dynamics
Wave propagation in a fluid flowing through a curved thin-walled elastic tube
No full textThe pulsatile flow in a curved elastic pipe of circular cross section is investigated.
The unsteady flow of a viscous fluid and the wall motion equations are written in a toroidal coordinate system, superimposed and linearized over a steady state solution.
Being the main application relative to the vascular system, the radius of the pipe is assumed small compared with the radius of curvature.
This allows an asymptotic analysis over the curvature parameter. The model results an extension of the Womersley’s model for the straight elastic tube.
A numerical solution is found for the first order approximation and computational results are finally presented, demonstrating the role of curvature in the wave propagation and in the development of a secondary flow
Thrombophilia, systemic inflammation and prevention of cardiovascular disease in children and adolescents with HIV infection
Full text linkLa malattia aterosclerotica inizia già dalla seconda decade di vita. Insieme ai tradizionali fattori di rischio associati (fumo, colesterolo, ipertensione) negli ultimi anni si è andata caratterizzando il ruolo dell’infiammazione, risultata, da studi di base confermati da numerose osservazioni cliniche, una componente patogenetica rilevante nell’insorgenza e progressione della lesione aterosclerotica.
Patologie associate ad infiammazione sistemica come il Lupus Eritematoso o la malattia di Kawasaki sono considerate condizioni a rischio moderato di aterosclerosi in età pediatrica. Anche l’infezione da HIV si associa ad alti livelli di infiammazione sistemica, fattore con un ruolo riconosciuto da tempo nell’accelerare l’immunodeficienza caratteristica della malattia. L’introduzione della cART (terapia antiretrovirale di combinazione) ha consentito negli ultimo 15 anni una riduzione straordinaria dell’incidenza di malattie opportunistiche associate all’AIDS (Sindrome da Immunodeficienza Acquisita), e una riduzione della mortalità, ma si è contemporaneamente assistito ad un aumento dell’incidenza di malattie non associate ad immunodeficienza, tra cui un ruolo principale è costituito dall’aterosclerosi e alle altre malattie cardiovascolari associate alla trombosi.
Nell’adulto un recente trial randomizzato (SMART trial) ha mostrato che la replicazione virale incontrollata risulta essere un fattore di rischio non solo per la progressione dell’immunodeficienza, ma anche per l’incidenza e mortalità da malattia cardiovascolare. Il ruolo dell’infezione da HIV come fattore di rischio per l’aterosclerosi e le malattie cardiovascolari è poco conosciuto in età pediatrica, popolazione in cui, anche se è minore l’incidenza di manifestazioni cliniche, tale indagine è resa più appropriata per il minore ruolo concomitante di altri fattori confondenti (es. ipertensione, iperglicemia).
In una prima fase del progetto di ricerca è stata indagata la prevalenza in bambini ed adolescenti con infezione da HIV seguiti presso l’Ospedale Pediatrico Bambino Gesù di Roma, della sindrome metabolica (ipercolesterolemia, iperglicemia, ipertrigliceridemia), già descritta e caratterizzata nei pazienti adulti con infezione da HIV in trattamento con farmaci antiretrovirali.
Successivamente, e per la prima volta, è stata indagata l’associazione tra replicazione virale, infiammazione sistemica e anomalie della coagulazione (trombofilia) in una coorte di bambini e adolescenti con infezione da HIV, producendo dati originali pubblicati nel Febbraio 2010 (Pontrelli et al, AIDS).
Sono stati studiati i livelli di attività della proteina S e proteina C anticoagulante e dell’antitrombina, insieme con il fibrinogeno, il D-dimero, la proteina C-reattiva e l’omocisteina. L’ipotesi che la viremia HIV determinasse aumento dei markers di infiammazione e alterazione dei markers di coagualazione è stata verificata confrontando i valori in pazienti con alta viremia (HVL, High Viral Load: HIV-RNA>1000 copie/mL) con i valori dei pazienti a bassa viremia (Low Viral Load, LVL: HIV-RNA<1000 copie/mL).
All’analisi univariata è seguita un’analisi multivariata che ha valutato il ruolo di altre variabili demografiche, cliniche e terapeutiche potenzialmente confondenti. Sono stati arruolati un totale di ottantotto pazienti (età media 13.5 anni, CD4 medi 30%, 72% pazienti nel gruppo LVL).
Lo studio ha evidenziato un deficit di proteina S e C anticoagulante rispettivamente del 51 e 8%. I pazienti nel gruppo HVL hanno presentato una riduzione significativa dei livelli di proteina S, proteina C e antitrombina, ed un aumento dei livelli di D-dimero.
La riduzione di proteina S (-11.2%, P=0.04) e l’aumento di D-dimero (+0.13mg/ml, P=0.004) sono risultati associati in maniera indipendente con l’alta viremia anche nell’analisi multivariata.
In conclusione lo studio ha dimostrato che in era cART, bambini ed adolescenti con infezione da HIV presentano un’alta prevalenza di alterazioni trombofiliche. L’analisi multivariata ha mostrato che la replicazione virale si associa in maniera significativa ed indipendente alla diminuizione della proteina S anticoagulante e all’aumento di D-dimero, suggerendo il vantaggio della terapia soppressiva sul mantenimento dell’omeostasi coagulativa e l’opportunità di una prevenzione attiva di tutti i fattori di rischio cardiovascolari a partire dall’età pediatrica.Atherosclerosis begins early in the lifetime and, as for other cardiovascular diseases associated with thrombosis, appears more relevant and anticipated in HIV-infected patients after combination antiretroviral therapy (cART) has reduced AIDS-related diseases and has improved survival.
Systemic chronic inflammation, a condition associated with HIV, could have a role in determining anticipated cardiovascular diseases since it is a risk factor for atherosclerosis. The association between viral replication, inflammation and coagulation abnormalities in a cohort of HIV-infected children and adolescents was investigated as aim of this research project.
In a first part of the research, prevalence of metabolic syndrome (hyper-cholesterolemia, hyper-trigliceridemia, hyper-glicemia), well characterized in adults on antiretroviral treatment, was studied in the cohort of children and adolescents. In the second part, assays on thrombophilia (protein S, protein C anticoagulant and antithrombin activity), were done together with fibrinogen, D-dimer, high-sensitive C-reactive protein, homocysteine and metabolic exams.
Patients with high viral load (HVL, HIV-RNA>1000 copies/ml) were compared with those in patients with a lower replication (LVL), adjusting for other demographic, clinical and therapeutic covariates. Eighty-eight patients (mean age 13.5 years, CD4 30%, 72% with LVL) were enrolled. A prevalence of protein S and protein C deficiency of 51 and 8% was, respectively, found. HVL group compared to LVL showed a significant reduction of protein S, protein C and antithrombin activities, and an increase of D-dimer levels. The independent association of HVL with decreased protein S activity (-11.2%, P=0.04) and increased D-dimer levels (+0.13mg/ml, P=0.004) was confirmed in the multivariate model.
In conclusion HIV-infected children and adolescents present high prevalence of thrombophilic abnormalities. The multivariate model confirmed that high viral replication is independently associated with decrease of protein S and increase of D-dimer, suggesting the advantage of suppressive therapy on coagulation homeostasis and the opportunity of an active control of cardiovascular risk factors starting at a younger age
Mass diffusion through two-layer porous media: an application to the drug-eluting stent
No full textA mathematical model for the diffusion–transport of a substance between two porous homogeneous media of different properties and
dimensions is presented. A strong analogy with the one-dimensional transient heat conduction process across two-layered slabs is shown
and a similar methodology of solution is proposed. Separation of variables leads to a Sturm–Liouville problem with discontinuous coefficients
and an exact analytical solution is given in the form of an infinite series expansion. The model points out the role of four nondimensional
parameters which control the diffusion mechanism across the two porous layers. The drug-eluting stent constitutes the main
application of the present model. Drug concentration profiles at various times are given and analyzed. Also, qualitative considerations
and a quantitative description to evaluate feasibility of new drug delivery strategies are provided, and some indicators, such as the emptying
time, useful to optimize the drug-eluting stent design are discussed
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