224 research outputs found
Characterization of focal liver lesions with pulse inversion mode and intermittent high mechanical index stimulation with Levovist.
No full textLinear and cyclic peptides as substrates for lyn tyrosine kinase
No full textTwo Tyr residues are supposed to play a crucial role in the regulation of protein tyrosine kinases of the Src family. Autophosphorylation of Src Tyr416 correlates with enzyme activation, while phosphorylation of C-terminal Tyr527 by Csk gives rise to inactive forms of Src kinases. It has previously been demonstrated that the Src-like tyrosine kinase expressed by the oncogene lyn displays a particularly high affinity (Km20 μm) toward the dimeric linear and cyclic derivatives of the heptapeptide H-Glu-Asp-Asn-Glu-Tyr-Thr-Ala-OH which reproduces the main autophosphorylation site of most of the Src enzymes. Under the experimental conditions used only one Tyr residue of the dimeric sequence can be phosphorylated [P. Ruzza, A. Calderan, B. Filippi, B. Blondi, A. Donella Deana, L. Cesaro, L. A. Pinna & G. Borin (1995) Int. J. Peptide Protein Res. 45, 529-539]. The present study addresses the problem of the efficiency displayed by Lyn towards the two Tyr residues located at positions 5 and 12 of the dimeric peptide. To this purpose, two tetradecapeptides were synthesized by the classical solution method, each containing one of the two Tyr residues alternatively replaced by Phe, and the corresponding univocal cyclic form. A possible correlation between the different structural properties induced by the modifications of the native sequence and the ability of the peptides to act as Lyn substrates was noted. The kinetic data obtained indicate that Lyn phosphorylates the residues located at different positions in the two linear analogues differently. In particular, while the Tyr5, Phe12 derivative presents a Kmvalue similar to those obtained for the dimeric linear and cyclic unmodified analogues, the Kmvalue of the Phe5, Tyr12 derivative is two-fold higher than those found for the above-mentioned peptides. Moreover, as previously reported for the linear and cyclic dimeric forms of the native sequence, in the mono-tyrosine containing series of dimers the still conformationally flexible cyclic derivative shows a phosphorylation efficiency two-fold higher than those found for the linear derivatives. © 1998 European Peptide Society and John Wiley & Sons, Ltd
Imaging of Penile Traumas – Therapeutic Implications.
No full textInjury to the penis may result from penetrating or nonpenetrating trauma. Nonpenetrating injury to the erect penis can produce albugineal tear, intracavernous hematoma or extraalbugineal hematoma from rupture of the dorsal vessels. Nonpenetrating injury to the flaccid penis usually follows blunt perineal traumas producing extratunical or cavernosal haematomas, or cavernosal artery tear followed by high flow priapism. Differential diagnosis between albugineal tear and other penile injuries must be obtained as soon as possible, since early surgical repair of albugineal tear reduces significantly the rate of postraumatic curvature and fibrosis. Ultrasonography (US) is able to detect the exact site of the tear in most patients as an interruption of the thin echogenic line of the tunica albuginea. Other imaging techniques are rarely required in the clinical practice. Color Doppler US is the imaging modality of choice to evaluate patients with high flow priapism. Focal or diffuse cavernosal fibrosis can be identified with US as echogenic areas in the cavernosal bodies. Postraumatic erectile dysfunction can result from fibrotic changes, nerve and vascular impairment or both. Doppler evaluation of penile vasculature is required in young patients with postraumatic impotence before surgical revascularization procedures
Characterization of focal hepatic lesions in cirrhotic patients by Pulse Inversion Harmonic Imaging US contrast specific technique with Levovist
No full textPURPOSE:
To evaluate the capabilities of Pulse Inversion Harmonic Imaging (PIHI) with hepatospecific US contrast agent Levovist in the characterization of focal liver lesions in cirrhotic patients.
MATERIALS AND METHODS:
Thirty-nine focal hepatic lesions in 25 consecutive cirrhotic patients identified by conventional ultrasound (US), were evaluated by color Doppler (CD), power Doppler (PD) with spectral analysis of tumoural vessels and PIHI. PIHI was performed 30 seconds (vascular phase) and 3-5 minutes (late phase) after Levovist injection. To definitely characterize the evaluated focal hepatic lesions, helical-CT (HCT) enhancement patterns (15 patients) and/or surgical/bioptic histologic findings (10 patients) were considered as reference procedures.
RESULTS:
Thirty focal hepatic lesions classified as hepatocellular carcinoma (HCC) by reference procedures appeared hypoechoic (n=19), isoechoic (n=5) or hyperechoic (n=6) on conventional US, with basket arterial pattern (n=10), vessels within the tumor (n=6), peripheral arterial pattern (n=4) or no vascular pattern (n=10) on CD/PD evaluation. On PIHI they appeared hyperechoic (n=26) or isoechoic (n=4) in the vascular phase, if compared to the surrounding liver parenchyma, and hypoechoic (n=23) or isoechoic (n=7) in the late phase. Four focal hepatic lesions classified as regenerative nodules (RNs) by reference procedures appeared hypoechoic on conventional US, with peripheral venous/arterial pattern (n=1) or no vascular pattern (n=3) on CD/PD. On PIHI they appeared hypoechoic (n=3) or isoechoic (n=1) in the vascular phase, remaining prevalently hypoechoic (n=3) or isoechoic (n=1) in the late phase. Five focal hepatic lesions classified as hemangioma by reference procedures appeared hyperechoic (n=4) or hypoechoic (n=1) on conventional US with few peripheral venous vessels on CD/PD. On PIHI they revealed progressive fill-in from the periphery toward the centre during the vascular and late phase after Levovist injectio
Fluid dynamic in vitro culture to investigate the interaction of nanoparticles with skeletal muscle
No full textExplanted muscles have been maintained in vitro under fluid dynamic condition
Rotational angiography of the carotid artery bifurcation: technical aspects and preliminary results.
No full textPURPOSE:
Rotational Angiography (RA), a new modality for performing conventional catheter angiography, enables an accurate evaluation of the artery to be obtained from different points of view by means of the contemporary rotation of the X-ray tube and image intensifier during intrarterial selective injection of contrast media. This paper describes the examination technique and compares the diagnostic accuracy of the RA oblique projections with the data obtained in the antero-posterior (AP) and latero-lateral (LL) projections in the study of the carotid bifurcation.
MATERIALS AND METHODS:
Thirty patients underwent RA of the supra-aortic vessels to evaluate the degree of a stenosis at the carotid bifurcation suspected at color Doppler imaging. The angiographic examinations were performed on a Philips Integris Allura system able to rotate the arc at a speed of 55 degrees /s with selective catheterisation of both common carotid arteries.
RESULTS:
The frame showing the greatest degree of stenosis was compared with the frames obtained in the AP and LL projections. 57/60 carotid bifurcations were assessable (3 cases of internal carotid arteries were obstructed). The degree of stenosis evaluated on the most significant of the oblique projections was superior to that shown in the AP and LL projections for 16/30 cases on the right side and for 14/27 cases on the left side. In 4/57 cases (7%) the degree of stenosis was modified from less than 70% to more than 70%. No adverse event was observed due to catheterisation.
CONCLUSIONS:
RA enables the complete three-dimensional evaluation of the carotid bifurcation, and generally yields more accurate information on the degree of the stenosis in comparison with AP and LL technique. The study was successfully carried out in all cases, however slightly longer examination times due to the setup requirements of the system. This was largely compensated by the quality of the information yielded, which required no additional projections to be performed. Moreover, the high frame rate of 25 frames per second showed the haemodynamic flow through the lesion
Does real-time spatial compound imaging improve US evaluation of the tunica albuginea? Preliminary assessment in patients with Peyronie’s.
No full textLuminescence and fluorescence of essential oils. Fluorescence imaging in vivo of wild chamomile oil
No full textEssential oils are currently of great importance to pharmaceutical companies, cosmetics producers and manufacturers of veterinary products. They are found in perfumes, creams, bath products, and household cleaning substances, and are used for flavouring food and drinks. It is well known that some of them act on the respiratory apparatus. The increasing interest in optical imaging techniques and the development of related technologies have made possible the investigation of the optical properties of several compounds. Luminescent properties of essential oils have not been extensively investigated. We evaluated the luminescent and fluorescent emissions of several essential oils, in order to detect them in living organisms by exploiting their optical properties. Some fluorescent emission data were high enough to be detected in dermal treatments. Consequently, we demonstrated how the fluorescent signal can be monitored for at least three hours on the skin of living mice treated with wild chamomile oil. The results encourage development of this technique to investigate the properties of drugs and cosmetics containing essential oils
Apporto della colnagio-rmn nella diagnostica delle vie biliari
No full textAbbiamo valutato il ruolo della colangio-RM nella diagnosi delle patologie delle vie biIiari e dei dotti pancreatici in relazione anche ai dati emersi dalla letteratura. Da febbraio2OO2
a luglio 2004 sono stati sottoposti a risonanza magnetica (RM) per lo studio delle vie biliari 252 pazienti consecutivi, con sospetto clinico o strumentale di patologia biliare. La diagnosi deflnitiva di patologia è stata ottenuta mediante intervento
chirurgico e/o colangiopancreatografia retrograda perendoscopica (ERCp) nei pazienti con clinica o evidenza diagnostica di malattia, mediante follow-up nei restanti
casi. La colangiopancreato-RM (CPRM), associata alla sequenza FSE T2 pesata sul piano assiale, è risultata positiva in 191/252 (75.79yo) pazienti, in 75/191 dei quali
(39.26%) si è reso indispensabile il ricorso a ERCP (n = SS) o è stato necessario l,intervento chirurgico b = qZ). CPRM e reperto chirurgico non concordavano tn 3/42 (7.14yo) casi operati; CPRM e ERCP sono risultate dlscordanti in 11/33 (33.38%) casi sottoposti a ERCP Fatta eccezione per i limiti associati alla difficoltà dl acquisire informazioni dinamiche relative a patologie funzionali dello sfintere di Oddi, per le
quali peraltro si sta registrando un progressivo aggiornamento tecnologico, la CpRM rappresenta la metodica diagnostica di riferimento nella patologia biliopancreatica, riservando all'esame endoscopico valenza terapeutica
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