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C Montanari

Publications and source records attributed to C Montanari.

53 records · Page 3Linked to original sources
PubMedDate not supplied

Effects of increased central dopaminergic tonus on gonadotropin secretion.

Gonadotropin secretion was investigated in 10 healthy volunteers (5 men and 5 women in the early follicular phase of cycle) by the following procedures: i) infusion of saline over 4 1/2 h period; ii) infusion of dopamine (DA) 4 microgram/kg bw/min over 4 h period; iii) oral administration of L-dopa (D) 100 mg plus carbidopa (C) 35 mg after 24 h pretreatment with C 50 mg every 6 h. This last pharmacological approach selectively enhances the central dopaminergic tonus. Blood samples were withdrawn every 15 min over 4 1/2 h period. No ultradian periodicity in LH and FSH secretion was observed. No significant modification in serum FSH levels was induced by any treatment at any time, while a significant decrease in serum LH concentration was observed from 45 to 240 min during DA infusion (-46.8%; p less than 0.005) and from 60 to 240 min after D + C administration -41.5%; p less than 0.05). These data demonstrate that, in humans, acute dopaminergic stimuli have an inhibitory action on LH release and suggest that this inhibition is exerted at the central level.

Administration, Oral↗
PubMedDate not supplied

[Cholesterol screening in a pediatric population at atherosclerotic risk].

We studied 344 children (174 girls and 170 boys) between the ages of 6 and 15 years (average age 11 years 9 months) chosen on the basis of a positive family anamnesis for dismetabolic and/or precocious cardiovascular pathologies, and also on the basis of objective data obtained at medical examinations, such as obesity and hypertension. These subjects underwent blood tests for glycaemia, total cholesterol, HDL cholesterol, LDL cholesterol and triglycerides. Children with total cholesterol levels above 170 mg/dl were considered to be hypercholesterolemic. 127 young people (65 girls and 62 boys) turned out to have excessively high cholesterol levels with an average level of 195.71 +/- 23.11 mg/dl and average LDL level of 127.05 +/- 25.08 mg/dl. 217 subjects (109 girls and 108 boys) turned out to be within the norm with total cholesterol level of 137.76 +/- 23.04 mg/dl and LDL cholesterol 75.59 +/- 22.89 mg/dl. We found a greater difference between the average values of LDL cholesterol and those of total cholesterol (40.5% compared to 29.61%), which shows that even at pediatric ages the LDL cholesterol concentration is the factor which best indicates the risk level for atherosclerotic development.

Adolescent↗
PubMedDate not supplied

Age-related modifications of heart rate during sleep-wakefulness cycle.

Twenty-four-hour monitoring of heart rate is currently used in cardiological practice, but it has been rarely applied to investigate the autonomic nervous system functioning. In the present study we investigated the heart rate of 275 healthy subjects, aged 15-69 years, divided into 11 groups by 5-year periods of age. Our results suggest that the balance between parasympathetic and sympathetic activities changes with advancing age. The parasympathetic activity becomes stronger and during sleep loses its power to modulate bradycardia. The general conclusion of our study is that all the investigations on cardiac autonomic functions are to be performed on age-matched basis.

Adolescent↗
PubMedDate not supplied

Structure and ultrastructure of the bone/ligament junction.

The tibial insertion of the patellar ligament of rat was investigated at light microscopy, scanning electron microscopy and transmission electron microscopy. Until the point of insertion, the patellar ligament showed the typical structure of a tendon. In proximity to the insertion, the ligament increased in diameter and was gradually infiltrated by a different, cartilage-like matrix. Its tenocytes became progressively rounded and displayed some characteristics of chondrocytes. Tendon fibres crossed this fibrocartilage and arrived well beyond the mineralization front. Finally, they appeared to interweave with the tibial diaphysis bone. These fibres were always distinct from the interposed extracellular matrix and exhibited a different pattern of mineralization from the matrix. Our observations indicate that fibrocartilage does not supersede tendon but merely infiltrates it. Thus, the tendon does not splay during articular movement and the tensile stress is redistributed across the insertion area by increasing the mechanical coupling among adjacent fibres. At the same time, this mechanism provides a structural, uninterrupted connection from tendon to bone which is consistent with the biomechanical requirements it has to withstand.

Animals↗