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Biomedical subjects

C Pastorino

Publications and source records attributed to C Pastorino.

At least 19 recordsLinked to original sources
PubMed2006

Static and dynamic properties of the interface between a polymer brush and a melt of identical chains.

Molecular-dynamics simulations of a short-chain polymer melt between two brush-covered surfaces under shear have been performed. The end-grafted polymers which constitute the brush have the same chemical properties as the free chains in the melt and provide a soft deformable substrate. Polymer chains are described by a coarse-grained bead-spring model, which includes excluded volume and backbone connectivity of the chains. The grafting density of the brush layer offers a way of controlling the behavior of the surface without altering the molecular interactions. We perform equilibrium and nonequilibrium molecular-dynamics simulations at constant temperature and volume using the dissipative particle dynamics thermostat. The equilibrium density profiles and the behavior under shear are studied as well as the interdigitation of the melt into the brush, the orientation on different length scales (bond vectors, radius of gyration, and end-to-end vector) of free and grafted chains, and velocity profiles. The obtained boundary conditions and slip length show a rich behavior as a function of grafting density and shear velocity.

Journal Article↗
PubMed1997

Leiomyomas of the gallbladder and splenic calcifications in an HIV-infected child.

Smooth muscle neoplasms seem to be particularly frequent in children with AIDS, and several cases of such lesions, both benign and malignant (leiomyomas and leiomyosarcomas), have recently been reported in the literature. We describe here the imaging findings in a boy with AIDS who developed two leiomyomas of the gallbladder wall as well as calcification of the intraparenchymal splenic arteries.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Screening for abdominal aortic aneurysms and associated risk factors in a general population.

OBJECTIVES: To evaluate the prevalence of abdominal aortic aneurysms (AAA) in a general population and to compare the results with those of similar studies in other countries. DESIGN: Ultrasound screening study and collection of clinical and biochemical data. SETTING: An urban Health Service District in Genoa, Italy. MATERIALS: A general population, aged 65-75 years, invited by personal letter between 1991-1994. RESULTS: 1601 subjects (741 males and 860 females) out of 2734 invited (58.5%) were evaluated. According to the ultrasound findings, 27 patients (1.7%) had an aortic dilatation of 26-29 mm; an AAA of 30-39 mm was found in 37 (2.3%) and an AAA > or = 40 mm in 33 (2.1%). The overall prevalence for AAA was 4.4% (8.8% in males and 0.6% in females respectively). The prevalence of smoking, alcohol consumption, coronary heart disease, chronic obstructive pulmonary disease and arterial disease were significantly higher in patients with AAA (p < 0.01). CONCLUSIONS: Ultrasound screening for AAA is a reliable and useful method and should be focused on men, regardless of concurrent disease.

Aged↗
PubMed1994

[Screening for abdominal aortic aneurysms in the general population. Preliminary results].

Between March 1991 and April 1993, 1188 subjects aged 65-75 years, out of 2734 invited, underwent abdominal ultrasound for screening of asymptomatic abdominal aortic aneurysms (AAA). For each patient the maximal anteroposterior and transverse diameters of the suprarenal and infrarenal aorta were measured. According to the literature data an AAA is defined as an aortic dilatation > 29 mm. AAA < 40 mm are followed by ultrasound every 6 months and the AAA > 39 mm are considered for surgical repair after complete clinical work-up. In addition any aortic dilatation ranging 26-29 mm is followed too, using the same criteria. The aorta was normal in 1112 patients (95.12%), an infrarenal aortic dilatation was found in 21 patients (1.79%), an AAA < 40 mm in 15 patients (1.28%) and an AAA > 39 mm in 21 patients (1.79%). The global prevalence of AAA > 29 mm was 3.07% (0.3% for the females and 6.8% for the males), similar to that reported by other authors. The statistically significant (p < 0.01) risk factors were: smoking, alcohol consumption, coronary disease and chronic lung obstruction. Hypertension and dyslipidaemia were not significant (but HDL-cholesterol and Apo-B), according to a different etiology of the aneurysms. In addition 38.5% of the patients had total cholesterol > 240 mg/dl but only 34.9% of these was under medical treatment and/or on a diet. Our preliminary data confirm the results of similar studies in other countries: screening for AAA is worthwhile on the general population and, looking to a better cost-benefit rate, it might be focused only on males.

Aged↗
PubMed1993

Analysis of echotexture of tendons with US.

To evaluate changes in echotexture of normal tendons at different frequencies and establish an anatomic correlation for fibrillar echoes, normal calcaneal tendons were examined in vitro at 7.5, 10, 13, and 15 MHz in calves (n = 8) and sheep (n = 6) and in vivo in humans (n = 8). Histologic correlation was obtained in vitro with 22-gauge needles that marked the position of echogenic fibrils under ultrasound (US) guidance. The human study group consisted of 25 patients with a clinical diagnosis of calcaneal tendon disease and 15 patients who underwent surgery for rupture of the Achilles tendon. At all four frequencies, normal tendons showed an internal network of fine parallel and linear fibrillar echoes that became more numerous and thinner as US frequency increased. These echoes were caused by specular reflections at the interface between collagen bundles and endotendineum septa. In patients, tendons showed a variety of basic changes in fibrillar pattern: increased fibrillar thickness (33 patients), interruption (17 patients), fragmentation (12 patients), and disappearance of echotexture (15 patients). It is concluded that US holds promise in detection of minimal changes in tendinous structure.

Achilles Tendon↗
PubMed1993

Case report: imaging of a bilobed gallbladder.

Imaging of the gallbladder demonstrates a wide range of anatomical variants, including anomalies in location, number and shape. Duplication anomalies are quite rare and are characterized by a large variety of configurations depending on the size and degree of fusion of the two lobes, and on the number and disposition of the cystic ducts. We present a case of a deeply cleft, bilobed gallbladder imaged by computed tomography (CT), ultrasonography (US) and oral cholecystography (OCG). The anomaly consisted of complete duplication of the body and fundus into two distinct and separated lobes both of which entered a single infundibulum. Awareness of congenital gallbladder variants may help in recognizing and correctly classifying gallbladder abnormalities, thus preventing misdiagnoses.

Adult↗
PubMed1992

Sonographic characterization of an accessory fissure of the left hepatic lobe determined by omental infolding.

This article describes the sonographic appearance of a very common accessory fissure of the liver located on the inferior side of the left lobe. The fissure was recognized in about 5% of 800 consecutive subjects and showed variable appearance owing to different insertion levels on the inferior hepatic surface. It extended from the left hepatic border to the Rex's recess or alternatively to the falciform ligament or the gallbladder fossa and contained the hepatogastric and hepatoduodenal ligaments, as demonstrated by laparotomy in six cases. At surgery, there was no evidence of thickening of Glisson's capsule at the fissure site, thus suggesting that the fissure is the result of extrinsic remodeling of the left lobe by omental infolding.

Adolescent↗
PubMed1992

[Color-Doppler echography of the testis. Study technique and vascular anatomy].

Color-Doppler sonography has recently made it possible to image scrotal vascularity non-invasively. This study was undertaken to determine the normal color-Doppler appearance and distribution of scrotal vessels and to define the technical principles of the examination. Color-Doppler imaging was effective in detecting both funicolar and testicular vessels. Among these, capsular (25/25), trans-testicular (10/25), centripetal and recurrent (25/25) arteries were easily identified. Waveforms analysis allowed to differentiate veins from arteries within testis and to distinguish (8/10) supratesticular (high impedance pattern with absent diastolic flow) from intratesticular arteries (low impedance pattern with high levels of diastolic flow). The optimal color depiction of scrotal vascularity needed the appropriate selection of several imaging parameters to increase detection of low-velocity, low-volume flows within the small testicular vessels. Such parameters included: PRF (ranging 1500 to 600 Hz), wall filters (ranging 25 to 50 Hz), color gain (maximized for optimal sensitivity while avoiding excessive color noise), color vs. echo priority (ranging 70 to 90%) and color persistence (adjusted to high values). In conclusion, color-Doppler imaging is capable of reliably showing the normal anatomy of testicular vessels. It could make a reliable substitute for scintigraphy and continuous wave Doppler in diagnosing scrotal conditions that alter blood flow.

Adult↗
PubMed1991

[Gastromiro vs gastrografin vs prontobario CAT for computerized tomography. Multicenter study].

The opacification of intestinal loops is mandatory, during CT examination of the abdomen, to prevent the gut from being mistaken for a pathological process or vice versa. The authors compared Gastrografin and Prontobarium-CT with a new, orally administrable, non-ionic contrast medium (Gastromiro) to investigate whether the non-ionic molecule presents any advantages over the other contrast media usually employed with CT. Five hundred ml of water solution/suspension at 11.1% (Gastromiro or Gastrografin) and 1.7% (Prontobarium-CT) were administered 20 minutes before examination to 818 consecutive patients. Different parameters were considered--i.e., patient tolerance as far as "taste and vomiting" were concerned, gut opacification, and any reaction which might have occurred to the patients within 24 hours after examination. The results, statistically analyzed, are the following: no significant difference in the quality of opacification of stomach, duodenum, and large bowel; significant difference in the quality of opacification of small bowel, where Gastromiro proved to have the highest contrast resolution; Gatromiro stimulated diarrhea significantly less than Gastrografin and Prontobarium-CT.

Barium Sulfate↗
PubMed1979

[Transgastric lymphadenography].

The transgastric lymphadenography technique carried out by the endoscopic route in 52 patients at the Digestive Endoscopy Centre of the 3rd Surgical Clinic of Rome University is described. On the basis of personal results it is considered that transgastric lymphadenography represents an interesting technique for the study of perigastric lymphnodes in normal and pathologic conditions. It is thought that it could also be useful in the study of the abdominal lymphatics although further verification and a larger series are necessary.

Gastritis↗
PubMed1978

ERCP, endoscopic papillotomy and gallstone removal by JFB2 Olympus and PFSB 1200 Machida.

ERCP is now used as routine technique and has provided a useful tool for both diagnostic and therapeutic purposes in diseases of the biliary tract. Until now this examination has been performed throughout the world including Italy, using preferably an Olympus JF and JF B2 sideviewing duodenoscope. In addition to 727 ERCP and 55 papillotomies performed using this instrument we have also employed a convertible endoscope Machida PFSB 1200; this fiberscope, with which front and side views are possible, can be used in the study of the oesophagus, stomach, duodenum, cannulation of the papilla of Vater and papillotomy. They results obtained and advantages offered by this instrument will be discussed. Since this endoscope is not usually employed, at least in Europe, for these purposes, we considered it of interest to report on the 251 ERCP and 9 papillotomies including stone removal performed in our department with the Machida PFSB 1200.

Aged↗
PubMed1977

Therapeutic colonoscopy.

The authors report their experience with regard to operative fibrecolonoscopy both in routine and emergency cases. After taking into consideration the use of this technique for the study and treatment of rectal and colonic polyps, they also recommend the use in emergency conditions of colonic haemorrhage and in the removal of foreign bodies. They conlcude that therapeutic colonoscopy must be recognised as one of the most useful methods of diagnosis and treatment of some lesions of the rectum and colon.

Adenocarcinoma↗
PubMedDate not supplied

Gradient echo MRI of portal vein thrombosis.

The MR appearance of thrombosis of the portal vein and its branches using gradient echo (GRE) sequences is described. The study consists of two separate parts. In the first part, five normal volunteers were examined to select the optimal section plane for each portal vessel to be studied. Given the "time of flight" effect of GRE sequences, a scan plane perpendicular to the direction of flow was used to obtain maximal signal enhancement of flowing blood. In the second part of the study, 13 patients with thrombosis of the portal system diagnosed by Doppler sonography, CT, and digital subtraction angiography were examined with the GRE technique. Gradient echo MR confirmed the presence and defined the extent of vessel thrombosis with high diagnostic accuracy. In addition, it proved accurate in detecting portosystemic collaterals. We concluded that the GRE technique can be effectively used as a complement to conventional SE MR to further delineate portal vessels.

Adult↗
PubMedDate not supplied

Advanced practice nursing role: nurse practitioner.

Nurse Practitioners are advanced practice nurses (APNs) who provide primary and acute care to individuals in many settings. The NP diagnoses and treats medical and surgical conditions that require acute, short-term management and chronic, long-term treatment. States vary in regulating processes regarding collaborative agreements, prescriptive authority, medical staff privileges, and insurance/third party reimbursement.

Drug Prescriptions↗