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Biomedical subjects

P Pirelli

Publications and source records attributed to P Pirelli.

13 recordsLinked to original sources
PubMed1997

A comparative light microscopic study of human midpalatal suture and periodontal ligament.

In order to provide information on the morphological features of both human midpalatal suture and periodontal ligament, bioptic samples were obtained from patients whose age was between 10 and 30 years. The samples were embedded in epoxy resin, sectioned, stained with toluidine blue and observed by light microscopy. The periodontal ligament and the midpalatal suture appeared very similar with regard to the histological characteristics of the connective tissue but differed in the nature of the bone tissue associated to it. The alveolar bone lining the periodontal ligament was a bundle bone whereas the bone lining the connective tissue of the sutures was both lamellar and bundle bone. The absence of osteoblasts, osteoclasts or undifferentiated cells in the sutures under examination suggests that they are subjected to a slow bone turnover during their life cycle. On the contrary, the presence of mesenchymal cells in the periodontal ligament supports the notion that these cells are precursors of osteogenic cells involved in the high rate of bone remodelling that characterizes the alveolar bundle bone. The present results are discussed taking into account physiologic and therapeutic aspects of the two structures under examination.

Humans↗
PubMed1986

Effects of digoxin, placebo and ibopamine on exercise tolerance and cardiac rhythm of patients with chronic post-infarct left ventricular failure.

This study compares the effects of digoxin, placebo and ibopamine (SB-7505), the orally active 3,4-diisobutyryl ester of N-methyl-dopamine, on exercise tolerance and cardiac rhythm of 14 patients whose left ventricular heart failure (end-diastolic pressure, 26.3 +/- 5.9 mmHg; ejection fraction, 0.42 +/- 0.10%) depended on a previous myocardial infarction. Patients were admitted to the study while on chronic oral digoxin treatment (serum levels between 1.1 and 1.9 ng/ml). Placebo instead of digoxin was given for the following month. Thereafter ibopamine 50 mg t.i.d. for one month was given. A sequence of one-month treatments with digoxin, placebo and ibopamine was repeated, then ibopamine was administered continuously for the next two months. The concurrent treatment (diuretics in all patients, nitroderivates in twelve, calcium antagonists in two) remained unchanged during the observation period. Symptoms-limited exercise tests and 24-h Holter recordings were obtained at admission, at the end of each one-month treatment and at the end of the observation period. Two patients developed unstable angina without increase of serum creatine phosphokinase while on ibopamine and were withdrawn. Out of the 12 patients that concluded the trial, one required supplementary doses of diuretic at the end of the second period on placebo. The results obtained during the trial suggest that: a) therapeutic plasma levels of digoxin have no deleterious effect on cardiac rhythm nor significantly increase exercise tolerance as compared with placebo; b) diuretics and nitrates appear to sustain the clinical stability of these patients as a group.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMedDate not supplied

A light microscopic investigation of the human midpalatal suture.

Biopsy samples of the human midpalatal suture, obtained from patients (age range: 10 and 30 yrs), were embedded in resin, cut with ultramicrotome and analyzed at light microscopy. The sutural connective tissue was made up of fibroblasts, collagen fibers, capillaries and nerve fibers. The sutural bone was made up of lamellar and bundle bone which alternated along both sides of the sutural connective tissue. No osteoblasts or osteoclasts were found, no signs of synostosis were ever detected. Our findings suggest that the lamellar bone replaces bundle bone when the suture is no longer involved in the growth of the palatal bones. The absence of bone remodelling shows that the sutures, at the time of sampling, were in a resting stage. Tissue architecture and cell types, so similar in samples from patients of such different ages, lead us to suppose that the sutures under examination are subject in time to very slow bone turnover.

Adolescent↗