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Biomedical subjects

C Fontana

Publications and source records attributed to C Fontana.

32 records · Page 2Linked to original sources
PubMed1988

Pulmonary vascular responses to forebrain stimulation in the cat.

The effects of forebrain stimulation on the pulmonary vascular bed were investigated in the intact-chest cat under conditions of controlled blood flow and constant left atrial pressure. When pulmonary vascular tone was raised to a high steady level, direct electrical stimulation of the forebrain elicited a biphasic change in lobar arterial pressure. The response was characterized by an initial transient increase in lobar arterial pressure that was followed by a prolonged secondary decrease in pressure. When a delay coil was added to the extracorporeal perfusion circuit, the secondary vasodilator response was separated into initial brief and delayed prolonged components, suggesting that it was mediated in part by the release of a humoral factor. The entire response to forebrain stimulation was abolished by cervical cord section or freezing. The initial constrictor response and early brief dilator response were not blocked by classic pharmacological blocking agents. The delayed humorally mediated vasodilator response was blocked by propranolol or ICI 118551, indicating that it was mediated by a circulating factor with beta 2-stimulating properties. The delayed vasodilator response was associated with a large increase in arterial epinephrine levels, and this rise in plasma epinephrine was not altered by propranolol. The present data suggest that electrical stimulation of the forebrain causes a prolonged pulmonary vasodilator response that is mediated by way of a descending pathway, which results in a large rise in arterial epinephrine levels.

Animals↗
PubMed1986

The distal pedicle fascia flap of the leg.

An anatomical study was undertaken in order to obtain data on the vascularity of the posterior fascia of the leg. Injection studies revealed there to be three "distal" pedicles; one between the peroneal and soleus muscles, emerging 10-15 cm above the lateral malleolus and two other, smaller ones, 5 cm above the medial and lateral malleolus. Clinical experience included seven cases: five with trauma and two with varicose ulcers. We had good results in five, a partial loss in one and a total loss in one. The distal pedicle fascia flap should be considered an alternative method for repairing defects in the lower third of the leg.

Adolescent↗
PubMedDate not supplied

Clostridial collagenase releases bioactive fragments from extracellular matrix molecules.

The current study was designed to investigate the biological role of small extracellular matrix fragments in wound healing. Human burn eschar tissue was digested with bacterial collagenase, and small aminoacidic fragments were inoculated in both human dermal fibroblast cultures and polyvinyl alcohol sponges implanted subcutaneously in the rat. Proliferation assays on cell cultures and biochemical and histologic analyses of the animal model were then performed. Results showed that fibroblasts treated with low concentrations of eschar fragments duplicated significantly faster than controls. Biochemical and histologic data from sponge implants showed that the inflammatory response was augmented by eschar-derived fragments at postoperative day 2, whereas protein and hydroxyproline synthesis were decreased at day 14. In conclusion, these data substantiate that the application of bacterial collagenase to débride necrotic tissue may have an indirect healing effect resulting from the local release of bioactive matrix-derived fragments.

Animals↗
PubMedDate not supplied

[Down Syndrome--a clinical, cytogenetic and epidemiologic analysis of 165 patients].

A clinical follow up of 165 Down Syndrome (DS) patients in an outpatient clinic programme at the Centro de Genética Médica (IFF - FIOCRUZ) was undertaken retrospectively. Clinical and laboratorial investigations were performed, such as cytogenetics and hematological analysis, thyroid hormones survey, abdominal ultrasound and cervical column X Rays. The clinical diagnosis of Down Syndrome was mostly performed during the first year of life, and 70% of all patients were under 4 years of age, being predominantly males. Trisomy 21 derived from non disjunction was found in 85% of the patients. The most common congenital malformation was cardiopathy (37.5%) and among all the clinical complications, repeated pneumonia could be evidenced in 30% of the patients, mainly during the first year of life. Leukopenia was observed in 14% of the patients and abdominal ultrasound scans allowed the early detection of biliary stones in 4.3% of the patients examined, a significative finding in the paediatric population. A prospective clinical programme aiming to anticipate the detection of clinical complications on at risk DS populations will fulfill its objectives and may act as a reducing factor in the infantile mortality rate.

English Abstract↗
PubMedDate not supplied

[The use of MPG in preventing the post-reperfusion injury of an epigastric island flap: an experimental study in rats].

The objective of this work was to study the protective effects of the free radical scavenger N2-mercaptopropionylglycine used in a rat model of reperfusion of epigastric island flaps submitted to transient occlusion of their vascular pedicles. In one group the epigastic vein of the flap was occluded for 5 hours. In the second group the epigastric artery was occluded for 21 hours and in the third group both the epigastric vein and artery were occluded for 8 hours. The scavenger or equivalent volume of saline solution was injected 10 minutes before the vascular occlusion and 10 minutes before declamping. The flap viability was assessed on the seventh day after flap reperfusion. In the three types of vascular occlusion a significant, and differential, increase of the areas of flap survival was observed. The protective effect of N2-mercaptopropionylglycine in reperfusion injuries was demonstrated.

Animals↗
PubMedDate not supplied

[Pulmonary lesion in electric injury: report of a case].

Major electrical injuries constitute approximately 5% of all admissions to Burn Units. Visceral complications are associated with a high mortality rate. The most common visceral lesions associated to electric burns are cardiac lesions. Pulmonary compromise is rare, if compared to inhalation injuries in termical burns. Although, when the entry or exit ports are the toracic wall, pleural effusion, hemotorax and pneumonitis may occur. A rare case of high-voltage electrical injury with massive pulmonary lesion is presented, regarding to clinical course and roentgenographic patterns.

Adult↗