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Biomedical subjects

F Rinaldi

Publications and source records attributed to F Rinaldi.

At least 19 recordsLinked to original sources
PubMed1990

Inhibition of intrinsic protein tyrosine kinase activity of EGF-receptor kinase complex from human breast cancer cells by the marine sponge metabolite (+)-aeroplysinin-1.

1. (+)-Aeroplysinin-1, a naturally occurring tyrosine metabolite from the marine sponge Verongia aerophoba, was found to inhibit the phosphorylation of lipocortin-like proteins by a highly purified preparation of the epidermal growth factor (EGF) receptor-tyrosine protein kinase complex from MCF-7 breast carcinoma cells. 2. (+)-Aeroplysinin-1 blocked the EGF-dependent proliferation of both MCF-7 and ZR-75-1 human breast cancer cells and inhibited the ligand-induced endocytosis of the EGF receptor in vitro. 3. Treatment with aeroplysinin-1 in the concentration range at 0.25-0.5 microM resulted in a time- and dose-dependent total tumor cell death in vitro. 4. At a 10-fold higher concentration the compound did not reveal any cytostatic activity in normal human fibroblasts. 5. From these data we conclude that (+)-aeroplysinin-1 represents a compound which displays a strong anti-tumor effect on EGF-dependent tumor cell lines.

Acetonitriles↗
PubMed1990

Global stability results for epidemic models with latent period.

In this paper, we analyse epidemic models with latent period. These models are characterized by the presence of the E class, that is, the class of population exposed to infection but not yet infectious. Global stability results are obtained for the nontrivial equilibrium for these models.

Disease Outbreaks↗
PubMed1990

[The use of CO2 laser in ambulatory dermatologic surgery].

The Authors assess the use of CO2 laser in out-patient dermatological surgery starting with the theoretical grounds for the use of laser surgery and including its practical application in out-patient clinics. Following a review of the literature, the paper describes the Authors' personal experience in the Laser Dermatological Surgery Outpatient Clinic of the Centro Resnati-Respighi at the San Raffaele Hospital in Milan. The efficacy and suitability of CO2 laser surgery are evaluated.

Ambulatory Care↗
PubMed1988

Global stability results for a generalized Lotka-Volterra system with distributed delays. Applications to predator-prey and to epidemic systems.

The paper contains an extension of the general ODE system proposed in previous papers by the same authors, to include distributed time delays in the interaction terms. The new system describes a large class of Lotka-Volterra like population models and epidemic models with continuous time delays. Sufficient conditions for the boundedness of solutions and for the global asymptotic stability of nontrivial equilibrium solutions are given. A detailed analysis of the epidemic system is given with respect to the conditions for global stability. For a relevant subclass of these systems an existence criterion for steady states is also given.

Animals↗
PubMed1988

Ultrasonography and alpha-fetoprotein in diagnosis of hepatocellular carcinoma in cirrhosis.

The accuracy of ultrasound (US) and alpha-fetoprotein (AFP) in the diagnosis of hepatocellular carcinoma (HCC) in 363 patients with cirrhosis (C) and a clinical suspicion of HCC was assessed. The ultrasonographic patterns of HCC and their relationship with AFP values were analyzed. Echographic patterns were distributed as follows: 47 patients had sonodense lesions; 30 patients had hypoechoic lesions; 47 had mixed-pattern lesions, and in four patients focal dilated intrahepatic bile ducts were demonstrated. The sensitivity of US was 90%; specificity was 93.3%. Serum AFP level greater than or equal to 500 ng/ml (RIA) was the first clue to the diagnosis in 71 patients (48.6%); specificity was 100%. In 28 patients AFP levels became significantly elevated during follow-up after US detection of HCC. No relationship between echo pattern and serum AFP levels was demonstrated. An algorithm for diagnosis of HCC is proposed.

Algorithms↗
PubMed1987

Ventilatory function in rubber processing workers: acute changes over the workshift.

When considering rubber tyre manufacturing from an occupational health viewpoint, three areas may be identified in which exposure to respirable materials are potentially harmful: the processing, curing, and talc areas. A study of the ventilatory function of the entire work force employed in the processing area in a rubber tyre manufacturing plant was undertaken to determine whether an acute reduction in lung function occurs over the course of their working shift (the plant worked a three shift system) and whether a chronic exposure to the occupational airborne contaminants causes permanent changes in lung function. The ventilatory function was measured at the worksite at the beginning and immediately after the end of the workshift. No evidence of chronic obstructive pulmonary disease was found and in most cases no significant decline in FEV1 was observed. Only one of the 79 individuals showed a moderate obstruction, measured by the ratio FEV1/FVC which gave the value of 0.55, with no variation over the shift. For non-smokers, the FVC, FEV1, and FEF25-75% were lower in those exposed for more than five years than in those exposed for five years or less. A similar pattern was also observed in the FVC and FEV1 of the smokers. None of these differences was statistically significant. Within each exposure group the pulmonary function of the smokers was lower than that of the non-smokers, but the only significant difference was found in the values of FEF25-75%. Only one man showed a decline in the FEV1/FVC ratio over the shift, but during each shift, a decrease in all the lung function tests was observed. The decrease was smallest during the first of the three shifts. These results are thought to support the hypothesis that there are acute adverse effects over an eight hour shift. Further investigations are needed to discover whether these acute changes in lung function result from a chemical stimulation or irritant receptors in the airways.

Adult↗
PubMed1984

Ultrasonographic and radionuclide detection of hepatocellular carcinoma in cirrhotics with low alpha-fetoprotein levels.

A total of 67 cirrhotic patients with clinically suspected neoplastic degeneration and low alpha-fetoprotein levels were assessed prospectively with ultrasound and gold (198Au) scintigraphy. Ultrasound showed space-occupying lesions in 22 of the 24 patients who had a final diagnosis of hepatocellular carcinoma (HCC) (sensitivity, 95.8%) and excluded the presence of HCC in 37 of the 43 patients with cirrhosis only (specificity, 86.0%; efficiency, 90.8%). Scintigraphy demonstrated a cold defect in 22 of the 24 patients who had a final diagnosis of HCC (sensitivity, 95.8%) and excluded the presence of HCC in 22 of the 43 patients with cirrhosis only (specificity, 51.1%; efficiency, 69.8%). It was concluded that the most accurate screening plain in cirrhotic patients suspected of having HCC with alpha-fetoprotein values below 500 ng/ml would consist of ultrasonography followed, as clinically indicated, by ultrasonographic or laparoscopic guided biopsy.

Carcinoma, Hepatocellular↗
PubMed1983

Percutaneous blind biopsy versus laparoscopy with guided biopsy in diagnosis of cirrhosis. A prospective, randomized trial.

A prospective controlled study of the diagnostic accuracy of blind percutaneous liver biopsy in comparison to laparoscopy plus guided biopsy for the recognition or exclusion of cirrhosis has been performed. One hundred twenty-six patients with a clinical diagnosis of chronic, diffuse, well-compensated liver disease were randomized into two groups and submitted either to percutaneous blind liver biopsy (PB: 64 patients) or to laparoscopy with guided biopsy (LB: 62 patients), in order to assess the accuracy of either procedure in diagnosing cirrhosis. PB correctly recognized or ruled out cirrhosis in 52 patients (82%). Inconclusive results were mostly false negative, as demonstrated by the presence on endoscopy of esophageal varices or by subsequent LB. LB demonstrated presence or absence of cirrhosis in all patients. The difference between the rate of accurate results of the two procedures is statistically significant. It is concluded that in patients without esophageal varices, LB should be the investigation of choice for the assessment of liver structure since the presence of cirrhosis can be missed in up to 20% of cases by PB.

Adult↗
PubMed1983

Ultrasound in the diagnosis of hepatocellular carcinoma associated with cirrhosis.

A total of 100 cirrhotic patients with clinically suspected neoplastic transformation was assessed prospectively with ultrasound. Ultrasound was diagnostic in 27/30 patients who had a final diagnosis of hepatocellular carcinoma (sensitivity 90%); there were five false-positive examinations (specificity 93%). The positive predictive value of the test was 84.4%; negative predictive value was 95%. Three different ultrasound patterns were observed in hepatocellular carcinoma: increased reflectivity, decreased reflectivity, and mixed echo pattern. Ultrasound can be used as a safe, effective first-line screening test for cirrhotic patients with clinically suspected neoplastic transformation.

Carcinoma, Hepatocellular↗