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Biomedical subjects

A Santucci

Publications and source records attributed to A Santucci.

At least 163 records · Page 9Linked to original sources
PubMed1989

A monoclonal antibody to a synthetic fragment of rabies virus glycoprotein binds ligands of the nicotinic cholinergic receptor.

Rabies virus glycoprotein and snake venom curaremimetic neurotoxins share a region of high homology (30-45 for neurotoxins and 190-203 for the glycoprotein) in the regions that are believed to be responsible for binding the nicotinic acetylcholine receptor. Monoclonal antibodies raised to the 190-203 synthetic fragment of rabies virus glycoprotein were immobilized on a high performance affinity chromatography column and were able to bind neurotoxins. Toxins were displaced from the affinity column by elution at acidic pH and by affinity competition with acetylcholine at neutral pH. Furthermore, the affinity column proved to be useful for the purification of cholinergic ligands. Overall, these results indicate that the paratope of our monoclonal antibodies could behave as an 'internal image' of the nicotinic cholinergic receptor acetylcholine binding site.

Amino Acid Sequence↗
PubMed1989

[Fibrinolytic activity and adhesive syndromes of the lumbar vertebral canal].

The recent studies, related in medical literature, indicate a reduced activity of fibrinolysis in patients with low back-pain caused by multiple factors (lumbar disc disease, post-laminectomy, post myelography) and suggest a new pathogenetic hypothesis of this disease and new therapeutic implications. The authors conducted a research based on the study of fibrinolysis in patients affected by post-surgical lumbar adhesive syndrome, with the aim of finding, eventually, a relationship between reduced fibrinolytic activity and clinical symptoms. The results are referred and discussed.

Adult↗
PubMed1989

Biological aspects of repair osteogenesis in corticospongy homologous grafts.

An experimental study was carried out aimed at studying the short-term, mid-term and long-term biological features of the incorporation of homologous bone grafts. Homologous cortical and corticospongy grafts of the proximal third of the tibia were implanted in 60 adult New Zealand rabbits, under general anaesthesia. The animals were sacrificed after predetermined periods of time, and the tibia removed for radiographic and histological examination. An analysis of the different phases of the fusion process allowed us to observe the different dynamic evolution of osteogenic repair of cortical as compared to spongy grafts. This could be explained by the different tensile properties of the two types of grafts.

Animals↗
PubMed1989

[Assessment of tolerability and antihypertensive efficacy of aceplus mite (captopril (CPT) 50 mg + hydrochlorothiazide (HCTZ) 15 mg): a double-blind study vs. HCTZ in diabetic hypertensive patients. A report on three treatments].

Thirty hypertensive diabetic patients were randomly, double blindly, treated with Captopril (CPT) 50 mg + hydrochlorothiazide (HCTZ) 15 mg (No 19) or HCTZ 25 mg alone (No 11) for 3 months, to assess blood pressure control and some metabolic modifications. The results indicate that CPT + a low dose of HCTZ maintains the synergistic effect of the two drugs, minimizing the metabolic problems related to HCTZ in hypertensive diabetic patients.

Adult↗
PubMed1988

High performance liquid chromatography immunoaffinity purification of antibodies and antibody fragments.

A rapid antibody purification method is described which combines high performance liquid chromatography (HPLC) resolution with affinity chromatography specificity. The antigen used as immobilized ligand is bound to the HPLC column matrix by reacting the amino groups of the protein with the active epoxy groups of the latter. Once the reaction has finished, the unreacted groups of the column are saturated with an appropriate scavenger. Unrelated proteins are then washed out and the specific antibodies recovered by lowering the pH of the elution buffer.

Animals↗
PubMed1988

Effect of angiotensin converting enzyme inhibition on platelet angiotensin II content.

The effect of captopril treatment on platelet angiotensin II levels was evaluated in 12 patients with essential hypertension. Captopril significantly lowered (p less than 0.01) mean arterial blood pressure in seven patients (Group 1) and was ineffective in five (Group 2). In Group 1, a marked decrease in plasma angiotensin II levels in both the supine (from 5.5 +/- 0.5 to 2.8 +/- 0.9 pg/ml) and the upright positions (from 17.5 +/- 4.7 to 3.9 +/- 1.6 pg/ml; p less than 0.0025) and a significant increase in platelet angiotensin II levels (from 10.5 +/- 5.3 to 22.4 +/- 17 pg/ml; p less than 0.05) after captopril treatment was observed. In Group 2, no variation was found in plasma angiotensin II levels, whereas platelet angiotensin II levels increased slightly (from 10.8 +/- 3.1 pg/ml to 16.9 +/- 5.2 pg/ml; NS). These findings suggest that the decrease in plasma angiotensin II levels can lead to an increase in platelet angiotensin II receptors or can lead to angiotensin II production in platelets through activation of a feedback mechanism. The second hypothesis suggests that platelets have alternative enzymatic pathways leading to angiotensin II production not inhibited by captopril.

Adult↗
PubMed1988

Antipeptide monoclonal antibodies inhibit the binding of rabies virus glycoprotein and alpha-bungarotoxin to the nicotinic acetylcholine receptor.

It has been reported that binding to muscle nicotinic acetylcholine receptor at the post-synaptic membrane is an important event of the rabies virus neurotropism. The binding site can be located within the 190-203 region of the virus glycoprotein sharing a high degree of homology with the "toxic loop" of the curare-mimetic snake neurotoxins. We have synthesized a tetradecapeptide corresponding to this glycoprotein region and used it, following conjugation with an immunogenic carrier to raise MAbs. We found that some MAbs raised against the peptide were able to recognize both the virus glycoprotein and the snake neurotoxin alpha-bungarotoxin; moreover, they can inhibit the binding of rabies virus glycoprotein and alpha-bungarotoxin to the nicotinic acetylcholine receptor extracted from the electric organs of Torpedo marmorata. On the basis of this cross-reactivity, we suggest that rabies virus glycoprotein and curare-mimetic snake neurotoxins share three-dimensionally similar structures in order to bind to the nicotinic cholinergic receptor. The potential use of the immunogenic properties of the peptide for the rational design of a synthetic vaccine against rabies is proposed.

Antibodies, Monoclonal↗
PubMed1988

Effect of nicardipine on angiotensin II platelet content.

We evaluated the effect of nicardipine treatment on platelet angiotensin II content in 18 essential hypertensive patients. Nicardipine induced a decrease in platelet angiotensin II content in all patients (-14%), but particularly in 10 (P less than 0.05; -20.5%). No other differences were found between these patients and the others. Further investigations are required to determine whether platelet angiotensin II content reduction contributes to the prophylactic and therapeutic effects of calcium antagonists on atherosclerosis.

Aged↗
PubMed1988

Blood platelets and angiotensin II: angiotensin II release after platelet aggregation.

Recent studies have demonstrated the presence of angiotensin II (Ang II) in human platelets. The aim of the present study was to determine whether in vitro platelet aggregation induces Ang II release. We studied 20 healthy volunteers, and found that some aggregant stimuli can cause the platelet to release this peptide. Release of Ang II was greater with thrombin (40.7%) than with ADP (29%), while N-ethylmaleimide was almost ineffective. The release of Ang II following in vitro aggregant stimuli suggests that this may be one of the mechanisms through which platelets can locally modulate vascular tone and perhaps promote atherogenesis.

Adenosine Diphosphate↗
PubMed1987

Treatment of bone cysts with methylprednisolone acetate. A 9 to 11 year follow-up.

The long-term results are reported of the treatment of bone cysts by means of the injection of methylprednisolone acetate (MPA) into the bony cavity using Scaglietti's technique. Eighteen patients were reviewed at a follow-up of 9-11 years from the beginning of the treatment. The results confirm the value of this technique and show a high percentage of recovery. During the growth period, a recurrence of osteolytic activity in the lesion may be observed after complete healing, though this does not happen frequently. In these cases further prompt treatment with MPA injected into the small osteolytic areas brings about their complete resolution. These observations lead us to conclude that a bone cyst can never be considered completely healed before complete skeletal maturity is reached. Regular radiological reviews must be carried out in order to recognise and treat promptly the first signs of a recurrence of cystic activity.

Adolescent↗
PubMed1985

Evolution and reversibility of damage to rabbit fallopian tubes after five sterilization methods.

The authors used a scanning electron microscope to study epithelial damage to the rabbit fallopian tube after sterilization with different methods and its subsequent capacity to regenerate after recanalization. Thirty female NZW rabbits were divided into five groups and sterilized using the following methods: 1) Madlener 2) Pommeroy, 3) clips, 4) unipolar coagulation, 5) bipolar coagulation. Each group was divided into subgroups of two and submitted at differing intervals to a second laparotomy, during which one tube was removed and the other anastomosed according to Winston's method. Four weeks after the second laparotomy all the rabbits were sacrificed, the remaining tube removed, and all tubes examined with the scanning electron microscope. The results indicate that mechanical methods of occlusion such as clips offer greater recovery possibilities than those in which the lesion is extended to the mesosalpinx. There further exists a correlation between the time that elapses after sterilization and regeneration of the epithelium.

Animals↗
PubMed1985

Relationship between vasopressin and the renin-angiotensin-aldosterone system in essential hypertension: effect of converting enzyme inhibitor on plasma vasopressin.

The effect of the chronic administration of captopril on plasma levels of vasopressin (PVP) were studied in 14 patients with moderate essential hypertension and 10 normal volunteers. All patients were studied after 10 days without drugs and under a constant diet (120 mmol sodium and 80 mmol potassium/day). Plasma levels of renin activity (PRA), aldosterone (PA) and PVP were assayed before and after captopril treatment (50-100 mg/day for 1 month). In addition to the well-known effect of captopril treatment on PRA and PA, a statistically significant reduction of PVP was observed. This finding suggests that the renin-angiotensin-aldosterone system influences vasopressin release, and its inhibitors may contribute to the absence of water retention during captopril treatment compared with the effect of other vasodilatory drugs.

Adult↗