Spin fluctuations in doped antiferromagnets from 7Li NMR relaxation in CuO:Li.
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Biomedical subjects
Publications and source records attributed to A Rigamonti.
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We followed 87 cirrhotic patients with esophageal varices and without previous hemorrhage for a mean period of 24 mo to prospectively evaluate the occurrence of variceal bleeding within (early) or after (late) 6 mo from entry and the contribution of portal Doppler ultrasound parameters to the prediction of early and late hemorrhage. Clinical, biochemical, endoscopic and portal Doppler ultrasound parameters were recorded at entry. Variceal bleeding occurred in 22 patients (25.3%). Nine (40.9%) bled within the first 6 mo. Cox regression analysis identified variceal size, cherry-red spots, serum bilirubin and congestion index of the portal vein (the ratio of portal vein [cross-sectional area] and portal blood flow velocity) as the only independent predictors of first variceal hemorrhage. Discriminant analysis was used to find the prognostic index cut off points to identify patients who bled within 6 mo (prognostic group 1) or after 6 mo (prognostic group 2) or remained free of bleeding (prognostic group 3). The cumulative proportion of patients correctly classified was 73% in prognostic group 1, 47% in prognostic group 2 and more than 80% in prognostic group 3. The addition of Doppler ultrasound flowmetry to clinical, biochemical and endoscopic parameter only improved the classification of patients with early bleeding.
The relationship of the endoscopic aspect of esophageal varices, portal quantitative Doppler ultrasound parameters and clinical and biochemical findings was assessed in 149 patients with cirrhosis stratified according to the presence of esophageal varices (n = 115) and the absence of previous bleeding (n = 96). In this series of patients the presence of esophageal varices and red signs proved to be significantly correlated with the severity of cirrhosis. However, in the group of patients with varices, no correlation was found between variceal size and the degree of liver failure. Portal blood flow velocity was significantly different in the endoscopic subgroups, but not in the clinical and biochemical subgroups. Furthermore, portal blood flow velocity was found to correlate only with the presence and size of esophageal varices. The Congestion Index of the portal vein (derived from the ratio between the cross-sectional area of the portal vein and the mean velocity of portal flow) was significantly different in most clinical, biochemical and endoscopic subgroups and was correlated with liver function, presence and size of varices, and presence and degree of red signs. We conclude that the Congestion Index of the portal vein, the clinical status and the endoscopic aspect of varices are not independent features in patients with cirrhosis. As for liver function and endoscopic findings, portal Doppler ultrasound parameters, in particular the Congestion Index, may contribute to a better clinical assessment in patients with cirrhosis.
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We analyzed the growth pattern of tumor masses and the survival of 39 asymptomatic Italian patients with a total of 59 small (less than or equal to 5 cm in diameter) hepatocellular carcinomas arising from cirrhosis. The total length of the observation period ranged from 90 to 962 days, with an average of 364 +/- 229 (mean +/- S.D.). Doubling time ranged from 27.2 to 605.6 days (mean +/- S.D., 204.2 +/- 135; median = 171.6 days). Three different growth patterns were recognized: (a) tumors with no or very slow initial growth pattern (doubling time greater than 200 days), 10 cases (37%); (b) tumors with declining growth rate over time, 9 cases (33.4%); and (c) tumors with almost constant growth rate, 8 cases (29.6%). Using the stepwise discriminant analysis, we found a score based on albumin, alcohol intake, number of nodules, echo pattern and histological type that allowed a correct prediction of short doubling time (less than or equal to 150 days) in 55.6%, medium doubling time (151 to 300 days) in 60% and long doubling time (greater than 300 days) in 100% of cases. The estimated survival rate of the 39 patients, calculated by the Kaplan-Meier method was 81% at 1 yr, 55.7% at 2 yr and 21% at 3 yr. Stepwise discriminant analysis showed that a score based on sex, HBsAg status, alcohol consumption, ascites, gamma-glutamyltranspeptidase, prothrombin time, Child-Pugh class and all the sonographical parameters could predict 2-yr survival in 100% of cases. We conclude that great variability of growth patterns exists among and within small hepatocellular carcinomas. Prediction of subsequent growth rate is unreliable in most cases.(ABSTRACT TRUNCATED AT 250 WORDS)
To establish the sensitivity and specificity of the mean portal flow velocity in the diagnosis of portal hypertension, a population of 304 consecutive cirrhotic patients, in whom 246 abdominal Doppler examinations were performed, was prospectively analysed between June 1988 and December 1990. To avoid equipment-related variability only examinations performed using the same equipment were considered. Further inclusion criteria were the absence of portal vein thrombosis or reversed flow in the portal vessels and the absence of spontaneous, ultrasonographically detectable, portosystemic shunts. The parameter evaluated was mean portal flow velocity calculated directly from the Doppler trace by specific, operator-independent, software. 123 patients satisfied the inclusion criteria. As a control group 60 healthy age- and sex-matched subjects were examined. Mean portal flow velocity was significantly lower in cirrhotic patients than healthy subjects (13.0 +/- 3.2 cm/s vs. 19.6 +/- 2.6 cm/s; p < 0.001). There was also a decrease in mean portal flow velocity in cirrhotics in each Child-Pugh category (13.8 +/- 2.8 cm/s in Child-Pugh A class; 12.1 +/- 3.5 cm/s in Child-Pugh B class and 11.0 +/- 2.4 cm/s in Child-Pugh C class) with a statistically significant difference between each Child-Pugh category and healthy subjects (p < 0.001), between Child-Pugh A and B (p < 0.01) and between Child-Pugh A and C (p < 0.005). The sensitivity and specificity of mean portal flow velocity in the detection of portal hypertension was then analyzed with the receiver operating characteristic curve.(ABSTRACT TRUNCATED AT 250 WORDS)
An increase in splanchnic blood flow in both arterial and venous beds has been demonstrated in inflammatory bowel disease (IBD) by means of angiographic and scintigraphic studies. Doppler ultrasound (US) enables a non-invasive evaluation of splanchnic arterial inflow in the superior mesenteric artery (SMA) and of venous outflow in the portal vein. The aim of this study was to assess the role of Doppler US in detecting changes in the hemodynamic variables measured in patients with IBD. Forty-five patients with IBD were studied, including 22 with Crohn's disease (CD) and 23 with ulcerative colitis (UC), and compared with 45 matched normal subjects. The mean velocity of portal flow (Vmean) and the resistance index (RI) of the SMA were evaluated by Doppler US. In CD the Vmean of portal flow was significantly higher in patients with active disease than in controls (p less than 0.001) and patients with inactive disease (p less than 0.001). The RI of the SMA was significantly lower in active disease than in controls (p less than 0.005), but no significant difference was noted between active and inactive CD. Also in UC, the Vmean of portal flow was significantly higher in patients with active disease than in controls (p less than 0.01) and patients with inactive disease (p less than 0.05). The RI of the SMA was significantly lower in active disease than in controls (p less than 0.005) and in patients with inactive disease (p less than 0.005). Doppler follow-up studies were carried out in 10 patients after initiation of treatment.(ABSTRACT TRUNCATED AT 250 WORDS)
Ultrasonographic screening and follow-up of patients with chronic liver disease lead to the detection of a large number of small asymptomatic hepatocellular carcinomas, so that the changing appearance of this neoplasm during its natural history has now been recognized. Ultrasonography provides information on shape, echogenicity, growth pattern and vascular involvement of the neoplasm. Three different shapes may be identified, depending upon the size and the invasiveness of the neoplasm: nodular, massive and diffuse. The echogenicity is variable and the tumour mass may appear hypo, hyper or isoechoic in comparison with the surrounding liver tissue. A mixed pattern and/or a hypoechoic ring may also be visualized. A tendency to change from a low echo pattern to a low periphery and finally to a massive pattern with increasing echogenicity has been shown in Japanese patients. The infiltrative growth pattern may be grossly distinguished from the expansive one on the basis of the aspect of the tumour boundary. Vascular invasion is easily recognizable as a mass within a major portal branch or even in the portal trunk. Duplex and color Doppler ultrasonography enable further insights on the vascular alterations related to this neoplasm. Abnormal signals, typical of HCC, are characterized by high-peak with broadening of spectrum. Low impedance continuous signals are less characteristic. Finally, ultra-sound guidance allows puncture of intrahepatic nodules as small as 1cm. The sensitivity of this procedure in the diagnosis of focal liver lesions is very high, varying between 91% and 95% with a specificity of 92%-100%.
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Propranolol has been demonstrated to be effective in lowering portal pressure in cirrhotic patients. This effect is mediated by a reduction of splanchnic arterial inflow and a consequent decrease of portal vein and portocollateral blood flow. Although experimental studies suggest a direct effect of the drug on portocollateral circulation, little information exists about relative flow changes occurring in the portal vein and in collateral veins feeding esophageal varices. This study addressed the problem in 12 cirrhotic patients selected on the basis of feasibility of Doppler flowmetry in both the portal and left gastric veins. Caliber, flow velocity and flow volume in both vessels were measured by Doppler ultrasound before and at 60, 120 and 180 min after an oral dose of 40 mg propranolol, together with heart rate and mean arterial pressure. A significant decrease in heart rate (-17.6% +/- 1.1%, p less than 0.001) and mean arterial pressure (-10.6% +/- 0.9%, p less than 0.005) confirmed effective beta-blockade. Baseline flow velocity was significantly lower in the portal vein than in the left gastric vein (12.4 +/- 0.6 vs. 15.4 +/- 1.5 cm/sec, p less than 0.05). Maximal hemodynamic effect was reached at 120 min after administration of propranolol. The vessel caliber did not change significantly. Flow velocity fell from 12.4 +/- 0.6 to 10.4 +/- 0.7 cm/sec in the portal vein (p less than 0.05) and from 15.4 +/- 1.5 to 11.1 +/- 0.9 cm/sec in the left gastric vein (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
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OBJECTIVES: To determine the suitability of the Migraine Disability Assessment (MIDAS) Questionnaire for assessing disability in children and adolescents with headache and to obtain preliminary information about disability in different primary headaches. BACKGROUND: During the last decade, researchers have begun to employ standardized methodologies to investigate the global impact of primary headaches. Disease-specific instruments have been developed to measure headache-related disability. The MIDAS Questionnaire, which is the most extensively studied of these instruments, was designed to assess the overall impact of headaches over the 3 months before compilation. The MIDAS Questionnaire is an optimal tool to assess headache-related disability in adults. METHODS: Ninety-five patients aged 7 to 17 years with tension-type headache, migraine, or both completed the validated Italian form of the MIDAS questionnaire on 2 occasions. Test-retest reliability was assessed by the Spearman rank correlation test. The Cronbach alpha assessed internal consistency. The patients answered questions about the adequacy of the questionnaire. RESULTS: The Cronbach alpha was.8. Correlation coefficients were generally high for the overall MIDAS score and for the items investigating disability in school and in family/leisure activities; they were lower for the items about housework. Most patients thought that the MIDAS Questionnaire was useful (98.9%) and that it captured the impact of their headaches (58.9%); 41% thought that questions about disability in housework were useless, 44.2% suggested adding questions regarding inability to do homework. All primary headaches had a considerable impact on daily activities, but patients with migraine tended to have lower headache frequencies and lower total disability time; those with tension-type headache suffered more days in which activities, although performed, were substantially impaired. CONCLUSIONS: The MIDAS Questionnaire is useful for assessing disability in children and adolescents with different primary headaches. Minimal changes in the phrasing and content of the items would be sufficient to render the MIDAS specific for the younger population with headache.