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Biomedical subjects

M Bertolotto

Publications and source records attributed to M Bertolotto.

72 records · Page 4Linked to original sources
PubMedDate not supplied

Color Doppler sonographic appearance of renal perforating vessels in subjects with normal and impaired renal function.

PURPOSE: The purpose of this study was to assess the prevalence and color Doppler sonographic characteristics of perforating vessels-small arteries and veins connecting the intrarenal vasculature with the capsular plexus-in healthy subjects, in hypertensive patients, and in patients with renal failure due to hypertensive nephroangiosclerosis or ischemic nephropathy. METHODS: Fifteen healthy subjects 24-34 years old, 15 healthy subjects 68-80 years old, 25 hypertensive patients, 25 patients with hypertension and chronic renal failure (15 mild, 10 severe), and 12 patients with hypertension and chronic renal failure and acute renal insufficiency due to ischemic nephropathy underwent color Doppler sonography of both kidneys. RESULTS: The few perforating arteries in healthy and hypertensive patients had various resistance indices and flow toward the capsule. Perforating veins in these patients were much more common than perforating arteries. Perforating arteries with a lower mean resistance index than the mean interlobar resistance index and flow toward the capsule were detected in 76% of kidneys in the patients with mild chronic renal failure and in 20% of those in patients with severe chronic renal failure. Only a few perforating veins were seen in patients with chronic renal failure. In 64% of the kidneys with renal artery stenosis detected in the patients with chronic renal failure complicated by acute renal insufficiency, there were perforating arteries with flow toward the kidney and a mean resistance index higher than the mean interlobar resistance index. CONCLUSIONS: Perforating vessels are recognizable using color Doppler sonography both in healthy subjects and in patients with renal failure. The prevalence and flow characteristics of perforating vessels differ between healthy subjects, patients with mild and with severe chronic renal failure, and patients with chronic renal failure complicated by acute renal insufficiency caused by renal artery stenosis.

Adult↗
PubMedDate not supplied

Staging of hilar cholangiocarcinoma with ultrasound.

The preoperative assessment of the extent of biliary and vascular involvement by hilar cholangiocarcinoma is clinically important because resectability may be limited by tumor extension along the bile ducts into the hepatic parenchyma or to the adjacent hilar vessels. Thirty-five patients with hilar cholangiocarcinoma were studied with ultrasound, and the results were compared with operative findings and other diagnostic modalities. The level of intrahepatic biliary obstruction was determined in 100% of patients with ductal ectasia, and a tumor mass was shown in 37.1%. Imaging and Doppler ultrasound proved accurate in detecting the neoplastic involvement of the portal vein. Both correctly diagnosed portal occlusion and wall infiltration in 4 of 4 and 15 of 18 (83%) patients, respectively, without any false-positives. On the contrary, imaging ultrasound had poor sensitivity in detecting infiltration of the hepatic artery (43%) and metastases in regional lymph nodes (37%), liver (66%), and peritoneum (33%). In conclusion, ultrasound may be valuable in the preoperative staging of hilar cholangiocarcinoma, specially in predicting ductal and portal involvement.

Adult↗
PubMedDate not supplied

Primary and secondary malignancies of the penis: ultrasound features.

Cancer of the penis is a rare neoplasm in developed countries but worldwide represents a significant health problem. In this study, the ultrasonographic features of primary and secondary malignant lesions of the penis are described. Squamous cell carcinoma usually presents as a hypoechoic lesion with heterogeneous appearance. Invasions of the corpora cavernosa and the corpus spongiosum are appreciable. B-cell lymphoma presents as well-vascularized mass, a plaque, or ulcers in the penile skin. Penile metastases results from hematogenous or lymphatic spreading of distant tumors or, more frequently, as penile infiltration by tumors from adjacent organs. Diffuse corporeal or nodular involvement can result.

Carcinoma, Squamous Cell↗
PubMedDate not supplied

Ultrasonography of the pancreas. 3. Doppler imaging.

Ultrasonography is probably the most widely used medical imaging technique. In fact, its non-invasivity, portability, widespread distribution and good clinical results have made it the preferred method for a first imaging approach to patients in a large variety of clinical settings. Ultrasound technology is advancing rapidly, aimed to increase image quality. In particular, increased color-Doppler sensitivity is contributing to the diagnosis and staging of pancreatic disease. Doppler studies are in fact integral part of ultrasound examination of the pancreas evaluating the peripancreatic vascular structures enclose portal vein, splenic artery and vein, superior mesenteric artery and vein, aorta, and inferior vena cava. While flows in all peri-pancreatic vessels are well recognized, only few parenchymal vessels are usually appreciable in normal conditions. Anyway the increased Doppler sensitivity allows the visualization of smaller peri-pancreatic and intra-pancreatic vessels. This article will review the technical background underlying the clinical application of Doppler ultrasonography in pancreatic imaging, with particular emphasis to normal vascular anatomy of the pancreas, and to the main applications of Doppler techniques in the different pancreatic pathologies.

Humans↗
PubMedDate not supplied

Dexamethasone -induced apoptosis of human monocytes exposed to immune complexes. Intervention of CD95- and XIAP-dependent pathways.

Monocytes and macrophages play a key role in the initiation and persistence of inflammatory reactions. The possibility to interfere with the survival of these cells, once recruited and activated at sites of inflammation, is an attractive therapeutic option. Although resting monocytes are susceptible to pharmacologically induced apoptosis, no data are available about the possibility to modulate the survival of activated monocytes. The present work was planned to investigate if dexamethasone is able to promote apoptosis of human monocytes activated by immune complexes. When monocytes were cultured with immune complexes, a dose-dependent inhibition of apoptosis was observed. Dexamethasone stimulated apoptosis of resting and activated monocytes in a dose-dependent manner. Both the immune complex inhibitory activity and dexamethasone stimulatory properties depend on NF-kappaB/XIAP and Ras/MEK/ERK/CD95 pathways. In fact, the exposure of monocytes to immune complexes increased NF-kB activation and XIAP expression, which in turn were inhibited by dexamethasone. On the other hand, immune complex-stimulated monocytes displayed a reduced expression of CD95, which is prevented by dexamethasone, as well as by MEK inhibitor U0126. Furthermore, anti-CD95 ZB4 mAb prevented dexamethasone-induced apoptosis in immune complex stimulated monocytes. Similarly, ZB4 inhibited dexamethasone-mediated augmentation of caspase 3 activity. The present findings suggest that Fc triggering by insoluble immune complexes result in the activation of two intracellular pathways crucial for the survival of monocytes: 1. Ras/MEK/ERK pathway responsible for the down-regulation of CD95 expression; 2. NF-kappaB pathway governing the expression of XIAP. Both the pathways are susceptible to inhibition by monocyte treatment with pharmacologic concentrations of dexamethasone.

Acridine Orange↗
PubMedDate not supplied

[Current role of color Doppler ultrasound in acute renal failure].

Acute Renal Failure (ARF) is characterized by a rapid decline of the glomerular filtration rate, due to hypotension (prerenal ARF), obstruction of the urinary tract (post-renal ARF) or renal parenchymal disease (renal ARF). The differential diagnosis among different causes of ARF is based on anamnesis, clinical symptoms and laboratory data. Usually ultrasound (US) is the only imaging examination performed in these patients, because it is safe and readily available. In patients with ARF gray scale US is usually performed to rule out obstruction since it is highly sensitive to recognize hydronephrosis. Patients with renal ARF have no specific changes in renal morphology. The size of the kidneys is usually normal or increased, with smooth margins. Detection of small kidneys suggests underlying chronic renal pathology and worse prognosis. Echogenicity and parenchymal thickness are usually normal, but in some cases there are hyperechogenic kidneys, increased parenchymal thickness and increased cortico-medullary differentiation. Evaluation of renal vasculature with pulsed Doppler US is useful in the differential diagnosis between prerenal ARF and acute tubular necrosis (ATN), and in the diagnosis of renal obstruction. Latest generation US apparatus allow color Doppler and power Doppler evaluation of renal vasculature up to the interlobular vessels. A significant, but non specific, reduction in renal perfusion is usually appreciable in the patients with ARF. There are renal pathologic conditions presenting with ARF in which color Doppler US provides more specific morphologic and functional information. In particular, color Doppler US often provides direct or indirect signs which can lead to the right diagnosis in old patients with chronic renal insufficiency complicated with ARF, in patients with acute pyelonephritis, hepatic disease, vasculitis, thrombotic microangiopathies, and in patients with acute thrombosis of the renal artery and vein. Contrast enhanced US is another useful diagnostic tool in patients with ARF which has been recently introduced in clinical practice. Microbubble administration may reduce technical failure in the evaluation of the renal artery. Moreover, perfusion defects due to stenosis or thrombosis of the renal segmentary vessels are better recognized. New diagnostic possibilities of enhanced US include evaluation of both cortical and medullar vessels, and functional evaluation of renal perfusion. Measuring the transit time of the microbubbles is useful for the diagnosis of renal artery stenosis and, in transplanted kidneys, for differential diagnosis between ATN and acute rejection.

Acute Kidney Injury↗
PubMedDate not supplied

[Magnetic resonance imaging of the small intestine and colon in Crohn's disease].

Three normal volunteers and 20 patients with known Crohn's disease were examined with MRI--at 0.5 Tesla and with a superconductive magnet. Coronal T1-weighted GE images were mainly acquired, before and after i.v. Gd-DTPA injection in breath hold (TR 70 ms, TE 13 ms, FA 70 degrees). MR findings were compared with the results of small and large bowel enema. In 6 patients (30%) the abnormal loops were missed. In the other 14 patients (70%) MRI did depict the affected loops in the same sites as depicted by conventional radiography. The bowel wall was thickened (4-10 mm) in all patients. In 10 patients the thickened wall was markedly enhanced after Gd-DTPA injection. In 6 patients MRI demonstrated disease complications--i.e., stenoses, fistulae and abscesses--missed by conventional radiography. In 7 patients MRI showed the bowel to be more involved than demonstrated by conventional studies. Bowel wall thickening appeared to be a constant and reliable sign of disease. Wall enhancement was a less frequent sign but, when present, it was considered as characteristic as wall thickening. In the staging of Crohn's disease, MRI yields more pieces of information than conventional radiography and depicts the involvement of the intestinal wall and of its surrounding spaces.

Colon↗
PubMedDate not supplied

[Role of the Doppler technique in the differential diagnosis of solid breast nodules. Personal experience].

The role of Doppler techniques in the differential diagnosis of benign from malignant solid breast lesions remains to be defined; indeed, it is still debated whether the diagnostic findings of Doppler US add further information to mammographic and B-mode US results. We investigated the diagnostic effectiveness of Doppler techniques in the differential diagnosis of breast nodules, especially in a selected group of patients with questionable diagnosis because of atypical morphological features or benign appearance detected in women over 40 years old. Color Doppler studies were performed on 111 breast nodules with solid features at US; 53 vascularized lesions were also studied with duplex Doppler. All the nodules were submitted to biopsy, which demonstrated 6 nonvascularized lesions to be complicated cysts. There were 105 solid breast nodules (65 benign and 40 malignant). Color Doppler US showed vascular signals in 71% of benign nodules, mainly at the periphery. 12% of benign nodules had Doppler signals of malignancy at color Doppler US; 92% of malignant lesions was vascularized, with irregular intratumoral signals in 37% of them. The peak systolic velocity and the resistive index were higher in malignant tumors (p < 0.02); peak systolic velocity changed in malignant lesions according to tumor size (p < 0.01). Color Doppler correctly suspected malignancy in 62% of the nodules with questionable features; conversely, 31% of the nodules with questionable findings and no color Doppler signs of malignancy proved malignant at biopsy. In conclusion, the role of Doppler studies remains currently limited in the differential diagnosis of solid breast lesions.

Adolescent↗