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Biomedical subjects

G Brotzu

Publications and source records attributed to G Brotzu.

At least 19 recordsLinked to original sources
PubMed1995

Evaluation of new small barium alginate microcapsules.

Microencapsulation of islets of Langerhans has been proposed in order to prevent immune rejection and possible recurrence of autoimmune disease. This study introduces a fast simple one-step microencapsulation procedure which allows the production of small sized barium-alginate beads. The volume of the microcapsules produced was approximately that of the encapsulated islets. Consequently, the insulin kinetics and the oxygen diffusion were favoured, while the transplanted tissue volume was reduced. Electron microscopy and immunoisolating testing were performed to evaluate the molecular cut-off, the physical and chemical characteristics of these microcapsules. Immunohistochemical staining and perifusion experiments of microencapsulated pancreatic islets showed their viability after the encapsulation procedure as well as in vivo experiments. In fact, microencapsulated porcine islets were implanted intraperitoneally into streptozotocin-diabetic rats. The xenografts reversed the hyperglycemic state and functioned for a period ranging from 9 to 385 days. The low mannuronic acid concentration and the purity grade of the alginate, exerted a combined influence on the capsule biocompatibility as in vivo studies showed.

Alginates↗
PubMed1992

[Acute diaphragmatic lesions due to closed thoracic-abdominal trauma].

Diaphragmatic injuries due to blunt trauma are steadily related to a high mortality. Their diagnosis may be difficult, due to the lack of specific symptoms and, more frequently to the high incidence of coexisting lesions which can mask the clinical appearance. This work presents the main aspects of ten cases admitted to the Emergency Surgery Division of Cagliari (USL 21), during the last seven years, with a review of the literature.

Abdominal Injuries↗
PubMed1991

Xenotransplantation of microencapsulated pancreatic islets contained in a vascular prosthesis: preliminary results.

Porcine and human pancreatic islets were microencapsulated in an alginate-polylysine biomembrane and put in a chamber of a new vascular prosthesis composed of an inner tubing of Dacron mesh and an outer tubing of expanded polytetrafluorethylene material. The vascular prosthesis was anastomized between the iliac artery and the contralateral vein of diabetic dogs. The recipients did not receive any immunosuppressive therapy. Function of porcine and human islets was monitored by measuring serum glucose levels and human C-peptide concentrations. After transplantation, serum glucose levels were maintained at values lower than 200 mg/dl, and C-peptide concentrations were between 0.8 and 3.2 ng/ml. Injected insulin requirements decreased by 50%-60%. Four to 8 weeks after transplantation, histologic examination showed well-preserved and functioning islets in the majority of intact microcapsules. Fibrin and inflammatory cells were not observed in the chamber. These data suggest long-term survival and function of microencapsulated pancreatic islets in the vascular prosthesis.

Adolescent↗
PubMed1991

Surgical treatment of hydatidosis.

Hydatidosis is particularly widespread in some geographic areas. Among these Sardinia presents one of the highest incidences. The authors examine the results obtained of 382 patients submitted to surgery between 1973 and 1989. The average age was 38.9 years. Liver involvement was observed in 215 cases, lung involvement in 167 cases, while localizations in other organs were rare. Forty liver cysts and 54 lung cysts were complicated preoperatively. The patients were submitted predominantly to total or subtotal cysto-pericystectomy (270 cases), parenchymal resection (75 cases), simple cystectomy (40 cases). Total postoperative mortality was 2.35%. Postoperative time was significantly shorter after cysto-pericystectomy and after parenchymal resection than after simple cystectomy. Patients suffering from multiple or complicated cysts were given supplementary chemotherapy.

Adolescent↗
PubMed1990

[Picotamide: prevention and therapy of diabetic vasculopathies. A double-blind clinical study].

Picotamide is the most interesting compound of 4-OH isophthalic acid. It is effective in vitro and in vivo. Picotamide induces inhibition of platelet aggregation: it is a thromboxane synthetase inhibitor and a thromboxane receptor antagonist. Picotamide causes cyclic endoperoxide accumulation and diverts their metabolism toward PgI2 synthesis in endothelial cells. PGI2 stimulates the adenylate cyclase with cAMP synthesis which makes platelets less sensitive to aggregatory stimulation. Picotamide induces enhancement of fibrinolytic activity, with significant reduction in the level of circulating plasminogen but in the same time it does not affect antithrombin III and FDP levels. In the present study picotamide or placebo were administered in a double blind trial at 600 mg daily for six months to 51 patients effected by diabetic macro and/or microangiopathy. The patients were 38 men and 13 women, the age was between 20 and 80 years (mean age 62.34). Twenty-seven patients were affected by type I diabetes and 24 by type II diabetes. Twenty-three of these patients presented macro-angiopathic lesions, 9 only microangiopathic lesions and 13 both. Twenty-five patients received picotamide and the other 25 an identical placebo for six months. One patient manifested myocardial infarction during the wash-out period and failed to enter the study. The following determinations were carried out: at T0 clinical examination, Doppler ultrasonography, Winsor Index, laboratory parameters; after 90 days (T90) clinical examination and Winsor Index and after 180 days (T180) were repeated photoplethysmography and clinical parameters too. Patients were not only evaluated for the vascular disease of lower extremities, but also for the other complications of diabetes, as retinopathy, nephropathy, cardiac and cerebrovascular disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

[Autotransfusion in vascular surgery].

This report describes 51 vascular patients with peripheral vascular disease treated intraoperatively by means of the autotransfusion apparatus with a minimum of 750 cc of reinfused blood. An early decrease of Hct, Hb, RBC, fibrinogen and Plt count was observed without any significant coagulation disorder.

Aged↗
PubMed1989

The importance of presynaptic beta receptors in Raynaud's disease.

The purpose of the present study was to investigate the effect of atenolol, a beta 1-selective blocker, along with flunarizine, a calcium antagonist, in the management of Raynaud's disease. Forty patients with Raynaud's disease were randomized into a trial in which atenolol (50 mg daily) was given with flunarizine (10 mg daily). During the trial all patients were subjected to finger photoplethysmography and were given a diary to note daily the number and duration of the crises and presence or absence of pain and paresthesia. The association of atenolol with flunarizine caused an 80% reduction in the number of vasospastic crises, a significant increase (p less than 0.001) in the photoplethysmographic wave amplitude, and complete disappearance of pain and paresthesia. These results were not observed in patients treated with a placebo. Flunarizine reinforces the action of atenolol in causing a decrease in vasoconstriction in patients with Raynaud's disease, as observed previously by us, in that it acts directly on the beta-presynaptic receptors or on the calcium slow channels connected to the beta-receptors. The present study confirms that the principal role in the physiopathologic progression of Raynaud's disease seems to be played by a modification of the beta-presynaptic receptors in the nerve endings of the peripheral vessels.

Adolescent↗
PubMed1988

Chest injuries. A review of 195 patients.

A retrospective analysis is presented of 195 consecutive patients with chest trauma, hospitalized from 1976 to 1984 at the Institute of Pathology and Surgery of the University of Cagliari. The most frequent causes were traffic accidents. In 11 patients the trauma was penetrating while 184 presented with blunt trauma. Conservative treatment was performed in 106, pleural drainage or thoracentesis in 29, and surgery in 60. Early osteosynthesis was performed in the 22 patients with flail chest and in 15 with multiple depressed fractures. Total mortality was 4.1%, and 13.6% in patients with flail chest. All deaths were associated with significant extrathoracic injuries.

Adolescent↗
PubMed1987

Beta-blockers: a new therapeutic approach to Raynaud's disease.

Thirty-six patients with Raynaud's disease (RD) were treated with a low dosage of beta-blockers, atenolol (50 mg/day) or propranolol (20 mg/day). Previous data have suggested that the pathophysiology of RD may be mediated by presynaptic beta-adrenoceptors. In this research we report that chronic beta-blocker treatment, at low dosage, can prevent the cold-induced vasospasm. The majority of patients (28) responded to atenolol, and 8 patients refractory to atenolol responded to propranolol.

Adrenergic beta-Antagonists↗
PubMed1985

Localization of substance P- and enkephalin-like immunoreactivity in the human paravertebral sympathetic ganglia.

The presence of substance P- and enkephalin-like immunoreactive nerve fibers and terminals is demonstrated in the human paravertebral sympathetic ganglia by an indirect immunofluorescence technique. Substance P-positive nerve structures appear in the form of fiber bundles, isolated varicose filaments and dot-like and basket-like nerve terminals around the neuronal cell bodies. Their density shows a remarkable individual variability. Enkephalin-positive nerve structures appear as isolated varicose filaments and dot-like nerve terminals, forming densely innervated patchy areas. No substance P- or enkephalin-containing cell bodies were detected. No overlapping seems to exist among the areas innervated by the two types of neuropeptides.

Aged↗
PubMed1985

The role of presynaptic beta-receptors in Raynaud's disease.

This report concerns the results of a study carried out to show the presence of presynaptic Beta adrenergic receptor supersensitivity in RD patients and the possibility to prevent or at least decrease this supersensitivity with Beta-blocker treatment. It is shown that the paradoxical vasoconstriction response to ISP infusion can be prevented in RD patients by the acute administration of Beta-blocker, such as Atenolol or DL Propranolol. Moreover, chronic treatment with the correct Beta-blocker was seen to prevent angiospastic crisis in these patients.

Adult↗
PubMed1984

Substance P-like immunoreactivity in human sympathetic ganglia.

Substance P-like immunoreactive nerve fibres and terminals are found in the human sympathetic paravertebral ganglia in connection with postganglionic neurones. Substance P may act as neurotransmitter or neuromodulator in the autonomic transmission in man.

Aged↗
PubMed1984

Stereomorphological arrangement of capillaries in skeletal muscle in normal and stenosed young and adult rats.

The stereomorphological arrangement of skeletal muscle capillaries depends on many factors. Genetic biochemical composition of muscle fibers, age, and training can interfere with the growth of the capillary network. This study is focused on the age effect of chronic reduction of blood flow, as in arterial stenosis, in skeletal muscle network of young rats when compared with adult rats. It has been observed that there is a statistically significant decrease of the length of short capillaries which cross the muscle fibers. In adult rats the opposite occurs.

Age Factors↗