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Biomedical subjects

M Salvatori

Publications and source records attributed to M Salvatori.

At least 19 recordsLinked to original sources

Steroid-protein interaction in human placenta.

Human placenta produces a large variety of bioactive substances with endocrine and neural competence: pituitary and gonadal hormones, hypothalamic-like releasing or inhibiting hormones, growth factors, cytokines and neuropeptides. The most recent findings indicate that locally produced hormones regulate the secretion of other placental hormones supporting a paracrine/autocrine regulation. In placental endocrinology, a particular relevance is played by steroid hormones. In fact, a specific gonadotropin-releasing hormone (GnRH)-human chorionic gonadotropin (hCG) regulation of placental steroidogenesis has been proposed as a placental internal regulatory system acting on steroids production from human placenta. In addition, activin and inhibin have been proposed as further regulatory substances of the synthesis and secretion of steroids; the addition of activin A to placental culture augments GnRH, hCG and progesterone, and this effect can be significantly reduced by the addition of inhibins. Finally, a steroid-steroid interaction is suggested by the evidence that placental estrogen has a positive role in the regulation of progesterone biosynthesis. Other steroid-protein interactions have been observed in human placenta. In fact, recent data indicate that progesterone inhibits placental corticotropin-releasing factor (CRF) and estrogens act on placental conversion of cortisol to cortisone, activating cortisol secretion by the fetal adrenal and enhancing fetal adrenal function with advancing gestation.

Animals

[Hepatobiliary scintigraphy in the study of neonatal hepatic cholestasis].

Severe neonatal cholestasis is a clinical problem requiring a differential diagnosis of intra- (hepatitis) and extrahepatic (biliary atresia) causes, prognosis and therapy being different in the two cases. Eighteen patients of pediatric age underwent US and hepatobiliary scintigraphy. US findings were aspecific in both hepatitis and biliary atresia. In the 11 patients with hepatitis, hepatobiliary scintigraphy after phenobarbital revealed labeled bile in the bowel. Only in 1 patient with cytomegalovirus hepatitis was a scintigraphic pattern similar to that of biliary atresia. On the contrary, no intestinal radioactivity within 24 hours was seen in 6 patients with biliary atresia. A portoenterostomy (Kasai's operation) was performed on 4/6 cases with biliary atresia. These patients were followed with hepatobiliary scintigraphy in order to evaluate anastomotic functionality. In a case of biliary cirrhosis secondary to occlusion, orthotopic liver transplantation was performed whose success was scintigraphically monitored. Our results point to hepatobiliary scintigraphy after phenobarbital as the best noninvasive procedure for both diagnosis and postoperative follow-up of biliary atresia. Labeled bile excretion within 24 hours was rarely found in both atresia and neonatal hepatitis.

Biliary Atresia

[Usefulness of radioisotopic methods in the study of the salivary glands].

The results achieved by dynamic and static salivary gland scintigraphy in 272 patients over a ten year time (January 1976-December 1985) are reported. On the basis of a semi-quantitative assessment of time/activity curves, dynamic studies prove to be the most suitable method for studying functional disorders (phlogosis, facial paralysis, etc.). Harmlessness, easy execution and functional results are the main advantages of radioisotope techniques. Salivary gland scintigraphy has some limits in the study of space occupying lesions (SOL): however, ultrasounds, CT and sialography represent the methods of choice in this field of salivary gland pathology.

Acute Disease

A practical approach to the hepatobiliary kinetics of 99mTc-HIDA. Clinical validation of the method and a preliminary report on its use for parametric imaging.

99mTc-diethyl-HIDA cholescintigraphy was performed on 24 patients with histologically proven liver disease and on 10 normal adult subjects. Liver mass transport of HIDA was interpreted with the aid of a probabilistic model, assuming that the tracer particles undergo mixed random walks with drifts. The radiohepatograms were thus fitted with a gamma-variate function and the fitting parameters were evaluated as estimates of the severity of the disease. These parameters, together with the transit times, were also used to generate parametric images of liver function. The advantages of this approach are discussed and the following conclusions are drawn: (1) The gamma-fit is highly satisfactory with any type of experimental curve (0.98 less than r less than 1). (2) The parameters derived from the gamma-fit make it possible to objectively assess the extent of liver functional impairment. (3) Parametric imaging of the liver mass transport of HIDA is easily implemented, but still more experience is needed to assess its impact on patient care.

Bile Ducts

The hepatic excretion of 131I-rose bengal and 99mTc-IDA derivatives in Rotor's syndrome.

Bilirubin kinetics and hepatobiliary excretion of some exogenous anions (BSP, 131I-rose bengal, diethyl and parabutly-IDA labeled with 99mTc) were studied in three patients presenting with Rotor's syndrome. Two were brothers; a nonjaundiced fraternal twin of one of them was also evaluated. The hepatic clearance of the radiopharmaceuticals was impaired in the affected patients but the degree of impairment was different among the tested anions, i.e., maximal for 99mTc-diethyl-IDA and minimal for 131I-rose bengal. Parabutyl-IDA was cleared better than the diethyl derivative. The metabolic derangement seems to be at the level of transfer from plasma to liver and of the hepatic storage, rather than at the level of hepatocyte excretory pathways, as in the case of Dubin-Johnson syndrome.

Adult

[Contribution of bidimensional echocardiography to the diagnosis of left atrial enlargement].

In 64 consecutive subjects (age range 17-69 years) we compared the antero-posterior (A-P) size of the left atrium estimated by M-mode and wide-angle two-dimensional echocardiography (short and long axis parasternal views). M-mode A-P diameter correlated both with short (r = 0.82) and with long (r = 0.76) axis A-P diameter. Subsequently we quantitatively analysed by two-dimensional echocardiography A-P, cranio-caudal (C-C) and latero-lateral (L-L) left atrial dimensions in 20 patients with mitral valve disease (age range 24-66 years) and in 24 normal subjects of comparable age range. Subjects with mitral valve disease had significantly higher A-P (P less than 0.001), C-C (P less than 0.02) and L-L (P less than 0.001) left atrial dimensions than normal controls. Both in normals and in mitral valve disease patients C-C was the view that showed the largest atrial diameter. Left atrial shape was however more spherical in mitral valve patients. Of these 7/20 (35%) had abnormal A-P diameter compared to the normal subjects. Patients with abnormal L-L and C-C left atrial dimensions were 9/20 (45%) and 7/20 (35%). Five of the patients with increased L-L size had a normal A-P diameter. Our results demonstrate the usefulness of wide-angle two-dimensional echocardiography in the assessment of the left atrial enlargement, especially in patients with negative or borderline M-mode echocardiographic data.

Adolescent