Biomedical subjects

R Massa

Publications and source records attributed to R Massa.

116 records · Page 7Linked to original sources

PubMedDate not supplied

The vasotocinergic system in the hypothalamus and limbic region of the budgerigar (Melopsittacus undulatus).

We report a morphological and biochemical analysis on the presence, distribution and quantification of vasotocin in the hypothalamus and limbic region of the budgerigar Melopsittacus undulatus, using immunohistochemistry on serial sections and competitive enzyme linked immunoadsorbent assay measurements on tissue extracts. Analysis of the sections showed large vasotocin-immunoreactive neurons in three main regions of the diencephalon, of both male and female specimens. Vasotocinergic cell bodies were located in the ventral and lateral areas of the hypothalamus, dorsal to the lateral thalamus and medial to the nucleus geniculatus lateralis. Immunoreactive neurons were placed also periventricularly, close to the walls of the third ventricle, at the level of the magnocellular paraventricular nucleus. Well evident bundles of immunoreactive fibers were placed ventral to the anterior commissure in the same regions of the hypothalamus and thalamus where vasotocinergic perikarya are localized. Fibers were identified close to the third ventricle, and in the lateral hypothalamic area along the lateral forebrain bundle. In contrast to what reported for other oscine and non-oscine avian species, we were not able to identify immunopositive neurons in any region above the anterior commissure, or detect relevant differences on the distribution of the vasotocin immmunoreactivity between sexes. Competitive enzyme linked immunoadsorption assay and image analysis of the extension of immunoreactivity in the tissue sections were consistent with the qualitative observations and indicated that there is no statistically significant dimorphism in the content of vasotocin or in the location and distribution of vasotocinergic elements in the investigated areas of male and female parrot brains.

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PubMedDate not supplied

Prevention of deep venous thrombosis in vascular surgical procedures by LMW-heparin.

The risk of Deep Venous Thrombosis (DVT) in the immediate postoperative period varies from 0.8 to 96% of cases depending on major or minor operations and on age of patients. We have employed 8,000 I.U. AXa/daily of LMW-Heparin injected subcutaneously from one day preoperatively and prolonged for 8 days after surgical procedures in 40 patients operated upon by an aorto-femoral bypass in 25 cases, a femoro-popliteal below the knee in 8 and an extra-anatomical bypass in 7. The onset of DVP in the lower limbs was investigated by clinical examination, venous Doppler pressure evaluation, waveform analysis and echotomography and the 125I-Fibrinogen uptake test. There was no intraoperative increased bleeding and the preclotting of the prosthetic grafts was inaffected. A DVT was detected during the second postoperative day, by means of the 125I-Fibrinogen test in the calf of only one patient (1/40-2.5%), submitted to an aorto-bifemoral bypass, in whom the clinical pattern and ultrasound investigations were negative. The single daily subcutaneous administration has never caused side effects in the site of injection and it seems a real improvement in the heparin treatment. These results emphasize the advantage of the use of LMW-Heparins in patients submitted to arterial surgical reconstructions of the lower limbs for the prevention of the DVT.

Aged↗

PubMedDate not supplied

Arterial repair of the lower limbs: prevention of prosthetic grafts occlusion by LMW-heparin.

The postoperative thrombosis of prosthetic grafts may be due to many factors: technical errors, poor run-off, prosthetic material, graft length, trauma by subcutaneous tunnellization or repeated microtrauma across the joint areas, evolution of atherosclerotic lesions, emorheological changes. In 50 patients submitted to surgical arterial repair of the lower limbs, we have employed 8,000 I.U. AXa/daily of LMW-Heparin, injected subcutaneously for 6 months after the operations to prevent immediate and late thrombosis. During the follow-up, one patient died, four stopped any treatment and in two the medication was changed. Hence our results are based on 43 cases: 10 patients operated upon by aorto-femoral bypass, 19 femoro-popliteal and 14 extra-anatomical procedures. During the follow-up all the patients were investigated by ultrasounds (pressure measurement, waveform analysis and duplex scanning echotomography); moreover 13/43 (30%) were studied by angioscintigraphy and 11/43 (25.5%) by a conventional or digital subtraction angiography. Thrombosis of the grafts at one year term occurred in none aorto-femoral, in one femoro-popliteal (5.2%) and in one extra-anatomical bypass (7.1%). This figure compares favourably with the results obtained in our experience in the patients treated by a variety of drugs. In such group the incidence of occlusion is 3.9% in aorto-femoral, 9.3% in femoro-popliteal and 11% in extra-anatomical grafts. Those results emphasize the possibility to improve the patency of the grafts in the arterial repair of the lower limbs by LMW-Heparin overall in femoro-popliteal and extra-anatomical areas.

Aged↗

PubMedDate not supplied

Xenon-133 muscular flow measurements in surgery for arterial disease of the lower limbs.

Muscular flow measurements were carried out in 34 patients with peripheral chronic arterial occlusive disease using the 133-xenon clearance method. The reactive hyperemia technique was preferred to the walking test. All the patients were investigated by angiography and 46 limbs were available for assessment. Control flow measurements were done after treatment in the following groups: arterial reconstruction in ten limbs of nine patients, unilateral lumbar sympathectomy in three and medical therapy in seven. Follow-up was from three to 12 months. The findings of flow measurements were of limited value in identifying the distribution of the arterial disease, but they provided a reliable means to predict the results of direct arterial repair in various procedures. They also proved to be a valuable method to assess the results of surgery. This does not seem to apply to lumbar sympathectomy or conservative treatment.

Aged↗

PubMedDate not supplied

Protective effect of clonazepam on ischemic brain damage induced by 10-minute bilateral carotid occlusion in Mongolian gerbils.

A 10-min bilateral carotid occlusion (BCO) in a control group of Mongolian gerbils, induced a transient generalized epileptic activity both in the hippocampal and in the cortical regions, associated with motor manifestations. After recirculation, spiking activity persisted, reaching its maximum peak within 18-36 h and then slowly decreasing till its total disappearance on the 6th-7th day. On the 7th day, histological studies manifested a selective loss of CA1 hippocampal neurons. The treated gerbils (divided in 2 groups according to the dosage used) were administered clonazepam (CZP), a benzodiazepine receptor agonist, immediately after clamping and again every 24 h for the following three days at dosages of 0.05 and 0.1 mg/kg i.p., respectively. The drug inhibited epileptic activity in a dose-dependent manner, while it prevented CA1 neuronal loss at both doses. These results point to a possible derangement of the GABAergic system which probably in turn triggers an exaggerated excitation.

Animals↗

PubMedDate not supplied

[Prenatal diagnosis of congenital cardiomyopathies. Current reality in the south of the country].

In order to make an actual perspective about prenatal diagnosis of congenital heart disease in the area of influence of our department, a prospective study including 948 fetus and 185 newborn was done, 348 fetus and 20 newborn evaluated during 1993 (group I) and the remaining during 1994 (group II). In both groups indications for fetal echocardiography were mainly maternal (18%) and familiar (14%) factors, but occurrence of CHD were respectively 2% and 0% for them. Fetal factors for echocardiography account for 7%, namely arrhythmias (7%) and obstetric suspicion of CHD (6%), but occurrence of CHD was respectively 13% and 32% for group I and 36% and 48% for group II. In the newborn with serious CHD, risk factors could be identified in 30% in group I and 36% in group II, being respectively 15% and 7% referred for fetal echocardiography. It is concluded that although a rise in the number of fetus evaluated and a better obstetric accuracy have occurred, the rate of prenatal diagnosis of CHD is still very low, pointing to necessity of continuing our actual policy of teaching and spreading this area, specially in the primary health care units.

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PubMedDate not supplied

111In-pentetreotide detection of gastrinoma before and after surgery.

Eighteen patients with Zollinger-Ellison syndrome were studied with 111In-pentetreotide SPECT in order to localize gastrinoma, the tumour responsible for this pathology. NMR imaging was also carried out. Eight patients were operated. 111In-pentetreotide was reinjected 4 hours before operation and the radioactivity of the excised tumours counted. The nature of the withdrawn tissues was assessed by immunohistochemistry (chromogranina A). The scintigraphy was repeated 3-6 months after surgery. 111In pentetreotide SPECT was more sensitive than NMR. It was also absolutely specific because all the radioactive tumours excised showed positive chromogranin A staining. The radioactivity/gram counted in gastrinomas exceeded 10 fold the hepatic and biliary radioactivity and 20-100 folds the radioactivity of blood and omentum. In all the operated patients but three, the scintigraphy performed after surgery did not detect tumours. However complete eradication did not occur, because though 3-6 months after surgery the gastrinemia was significantly lower with respect to pre-surgery results it did not return to normal values in all patients but two.

Chromogranin A↗

PubMedDate not supplied

In vivo study of a technetium labelled anti-EGFr MoAB.

Epithelial Growth Factor receptors (EGFr) are normally present in all the epithelial cells, but their overexpression is closely related to presence of cancer. We have raised EGF-competitive antibody against EGFr and have labelled it with 131I and technetium. The ability of this antibody to bind to A431 cells to be internalized has been tested on A431 cells cultures. Its ability to give scintigraphic images of epithelial tumors has been tested on nu/nu balb c mice xenografted with A431 cells. The labelled antibody is well internalized by cultured cells. Xenografted tumors are clearly imaged both by 131I and 99mTc anti EGFr Mo/Ab. 99mTc labelling is very interesting. The tumor/background ratio was 0.72 +/- 0.2 for 99mTc and 0.40 +/- 0.6 for 131I labelling. Moreover very high uptake of 99mTc MoAb was obtained 2 hours after injection whereas the 131I antibody required 24 hours.

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