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Biomedical subjects

G Piazza

Publications and source records attributed to G Piazza.

At least 37 records · Page 2Linked to original sources
PubMed1995

AMPA receptor activation regulates the glutamate metabotropic receptor stimulated phosphatidylinositol turnover in human cerebral cortex slices.

The effect of excitatory amino acids (EAA) on phosphatidylinositol (PI) turnover in human cerebral cortical slices was investigated. Trans-1-aminocyclopentane-1,3-dicarboxylic acid (ACPD) increased inositol phosphate (IP) formation in the 1-1000 microM range. Quisqualic acid (QA) was maximally effective at 10-100 microM, showing an inverse correlation between concentration and effect in the 100-1000 microM range. The glutamate metabotropic receptor antagonist 2-amino-3-phosphonopropionic acid (AP3), the ionotropic non-NMDA receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) and the NMDA channel blocker dizolcipine (MK-801) failed to prevent the PI response to ACPD (1000 microM). However, CNQX (100 microM) modified the concentration-response curve of QA reducing the effect of QA 10 microM by approx. 50% and enhancing that of QA 1000 microM by 2-fold. In addition, CNQX (100 microM) together with MK-801 (100 microM) unmasked the ability of L-glutamate (L-GLU) 3000 microM to stimulate PI turnover. The effect of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) on the EAA-induced PI turnover was also studied. AMPA (0.1-1 microM) potentiated the response to submaximal (30 microM) ACPD and (1 microM) QA concentrations. However, higher AMPA concentrations (10 microM) failed to synergize with ACPD 30 microM and, in addition, inhibited the PI turnover maximally stimulated by QA 10 microM. These results further support the presence of the glutamate metabotropic receptor in the human neocortex. In addition, they show the occurrence of a concentration-related dual interaction between AMPA and glutamate metabotropic receptor activation in the IP formation in this brain area.

6-Cyano-7-nitroquinoxaline-2,3-dione↗
PubMed1995

Diffuse leptomeningeal gliomatosis with osteoblastic metastases and no evidence of intraaxial lesions.

An autopsy-proved case of cerebral and medullary leptomeningeal gliomatosis and diffuse osteoblastic metastases without evidence of intraaxial tumor is described. MR findings included diffuse thickening of the cerebral and medullary leptomeninges on T1-weighted, proton density-weighted, and T2-weighted images and abnormal enhancement of the sulci and cisterns of the cerebrum, brain stem, cerebellum, and medulla on postcontrast T1-weighted images. MR also showed several areas of replacement of the normal bone marrow of the skull. No intraaxial lesion was seen.

Adult↗
PubMed1995

[Urinary cytology of transitional-cell carcinoma].

The authors report on their experience about urinary cytology in 1991. They studied 100 patients with cytology and histology, carried by cystoscopy and cold-mapping biopsy, trying to have notice about cytological value and proficiency.

Biopsy↗
PubMed1994

Cruciate paralysis from a Jefferson's fracture. Report a case and review of the literature.

A case of post-traumatic cruciate paralysis with a Jefferson's fracture was observed in a 54-year-old patient who fell accidentally. Cruciate or Bell's paralysis is a condition caused by incomplete cervical spinal cord lesion linked to focal and reversible damage of the pyramidal tract at the level of the decussation. The patient was treated by S.O.M.I. brace and a Philadelphia collar with a complete neurological restitution.

Cervical Atlas↗
PubMed1993

Insulin-like growth factor 1 and sodium-lithium countertransport in essential hypertension and in hypertensive left ventricular hypertrophy.

OBJECTIVE: The aim of this work was to study the insulin-like growth factor 1 (IGF1), a substance able to promote cell proliferation in vascular smooth muscle, in patients with mild-to-moderate hypertension and to analyse its relationship to sodium-lithium countertransport, a genetic marker of hypertension that is related to cardiovascular complications. METHOD: We studied 32 hypertensive subjects, some with left ventricular hypertrophy, and 14 healthy subjects. Fasting plasma IGF1 was measured by means of a radioimmunoassay after octadecylsilica chromatography and Na(+)-Li+ countertransport was determined by the method of Canessa. RESULTS: Hypertensive patients had higher values of both IGF1 and Na(+)-Li+ countertransport. We found a positive correlation, irrespective of age, between IGF1 and Na(+)-Li+ countertransport. The patients with left ventricular hypertrophy had significantly higher plasma IGF1 levels than those without left ventricular hypertrophy. CONCLUSION: Our results confirm a possible role for IGF1 in the cardiovascular complications of hypertension and emphasize its relationship to genetically determined factors.

Adult↗
PubMed1992

[Costo-clavicular outlet syndrome].

Syndromes caused by the compression of the neurovascular bundle are not a rare pathology, though their exact frequency cannot be assessed. Neurovascular bundle in the upper limbs may be compressed at the costo-clavicular space, interscalene triangle or at the insertion of the minor pectoralis muscle into the coracoid process. More than 90% of patients present neurological symptoms and 10% also have vascular problems. Diagnosis depends on a careful clinical and instrumental study of the patients. Arteriography, phlebography and Doppler tests were of value in the diagnostic approach, showing the compression of the subclavian artery and vein using the arm abduction manoeuvre. Electromyography is of value in differential diagnosis of the carpal tunnel syndrome showing the entity and site of nerve compression. The best form of surgical treatment is resection of the first rib according to Roos, using an extrapleural and transaxillary route.

Adult↗
PubMed1992

Intracranial lesions of surgical interest in minor head injuries in paediatric patients.

Among 62 children and adolescents (1-16 years) admitted over a period of 3 years (1987-1989) with a minor head injury, 33 (53%) were found to harbour intracranial lesions of surgical interest. The most frequent lesion found was extradural haematoma (17 cases), followed by cerebral contusion (7 cases), depressed fracture (4 cases), depressed fracture with underlying contusion (3 cases) and pneumocephalus (2 cases). A skull fracture was present in 88% of patients with an intracranial lesion and in 50% of patients without lesions. Fifteen patients underwent surgery for an extradural haematoma or a depressed fracture. All had a good recovery. No correlation was found between age and Glasgow Coma Score on the one hand, and the incidence of both the presence of intracranial lesions and the necessity of surgical treatment on the other. The only important risk factor proved to be a skull fracture, which had occurred significantly more often in patients with intracranial lesions than in those without any.

Adolescent↗
PubMed1992

Insulin resistance and endogenous digoxin-like factor in obese hypertensive patients with glucose intolerance.

Hypertensive obese subjects with glucose intolerance have hyperinsulinaemia, insulin resistance and intracellular cation imbalance resulting in increased sodium content. The aim of our study was to assess in these patients plasma levels of endogenous digoxin-like factor (EDLF), an inhibitor of the sodium-pump mechanism. We studied 14 hypertensive and 12 normotensive subjects with obesity and glucose intolerance for fasting blood glucose, and plasma insulin, C-peptide and EDLF levels: the two groups were matched for age and BMI and were studied after a 2-week wash-out period from hypotensive drugs. Compared with normotensives, hypertensive subjects had higher plasma insulin levels, a greater immunoreactive insulin/C-peptide ratio, a lower glucose/insulin ratio and higher plasma EDLF levels. Our results confirm that among obese people with glucose intolerance, hypertensives are more hyperinsulinaemic and insulin-resistant than normotensives and indicate that the intracellular cation imbalance in these patients may be attributable, at least in part, to EDLF.

Blood Glucose↗
PubMed1992

[Aneurysm of the subrenal aorta. Comments on 25 cases seen].

The authors report their experience in the diagnosis and treatment of subrenal aortic aneurysms. The incidence of the abdominal aortic aneurysms, in aged population, is increasing, linked, in 95% of cases, to atherosclerotic disease. The diagnosis is essentially clinical with help of various examination techniques, that provide an accurate preoperative morphological assessment, like direct X-ray of the abdomen, echography, angio computerized axial tomography and arteriography. The moment for operating aneurysms of the subrenal aorta is discussed. The rate of operative deaths following elective replacement of abdominal aortic aneurysms is less than 4% and it increase to 40-80% in emergency replacement for rupture. Rupture remains a catastrophic life-threatening complication for cardiovascular, respiratory and renal failure, in spite of improved surgical techniques and postoperative intensive care.

Aged↗
PubMed1991

Nifedipine vs. enalapril in treatment of hypertensive patients with glucose intolerance.

To compare the metabolic effects of nifedipine and enalapril, we studied 21 obese patients (BMI of 31.6 +/- 1.1) with mild-to-moderate hypertension and glucose intolerance. None of the patients were receiving insulin or hypoglycemic agents. After a washout period of 15 days, blood pressure was recorded and fasting blood glucose, insulin, and lipid concentrations were determined. At random, 11 patients were started on nifedipine and 10 patients on enalapril. At the 90th day of treatment, clinical and laboratory tests were again performed. Both of the drugs reduced blood pressure values comparably. No significant variation of metabolic parameters was found after 90 days of treatment in the enalapril group. In the nifedipine group, the fasting insulin level was decreased and the glucose/insulin ratio was significantly increased, suggesting an improvement in insulin sensitivity; moreover, total plasma cholesterol was significantly reduced. Enalapril and nifedipine seem to be effective and safe drugs in the treatment of hypertensive subjects with obesity and glucose intolerance. Nifedipine can ameliorate insulin resistance and the lipid state.

Blood Glucose↗
PubMed1990

Lymphocyte subsets in bronchoalveolar lavage fluid and in circulating blood in epidermoid bronchogenic carcinoma.

Alveolar macrophages, lymphocyte and granulocyte percentages, together with OKT3+, OKT4+, OKT8+ lymphocyte subsets and OKT4+/OKT8+ ratio, were evaluated in bronchoalveolar lavage (BAL) fluid and in peripheral venous blood (PVB) of neoplastic and nonneoplastic subjects, in order to assess these aspects of immunity in neoplastic disease and to find out if the modifications in the bronchoalveolar environment are correlated to the ones in the circulation blood. BAL was performed in 30 patients undergoing fiberoptic bronchoscopy to ascertain the presence of lung cancer. Twelve of them had positive findings for epidermoid bronchogenic carcinoma, while in the remaining subjects the diagnosis was not confirmed. The 30 examined subjects were then grouped according to their smoking habit. In PVB, no significant difference was seen between neoplastic and nonneoplastic subjects, whereas in BAL the neoplastic patients showed a significant increase of lymphocytes OKT3+ and OKT8+. This tends to confirm that PVB is not a good indicator of organ immunity and may justify the reduced activity of alveolar macrophages in subjects affected by bronchogenic neoplasia. Between smokers and nonsmokers, lymphocyte subsets showed more significant differences than between neoplastic and nonneoplastic subjects (decrease of T4+ lymphocytes, increase of T8+ lymphocytes and, therefore, reduction of T4/T8 ratio); there were also scalar variations in the three groups (smokers with cancer, smokers without cancer and nonsmokers without cancer). Thus, the possible autonomous role of cigarette smoke and the presence of neoplasia in the immunity alterations of the alveolar environment with final joint effects were confirmed. These data may indicate a possible correlation between cigarette smoking, immunological alterations in BAL and the onset of bronchogenic carcinoma.

Adult↗
PubMed1989

Asymptomatic extradural haematomas. Results of a multicenter study of 158 cases in minor head injury.

The authors report a study conducted in three Italian neurosurgical centres on 158 patients admitted after a minor head injury and with CT findings of a hitherto asymptomatic significant extradural haematoma. All patients were examined both prospectively by means of a computerized record containing 18 clinical and radiological parameters, and retrospectively by logistical regression analysis, in order to ascertain which factors influenced most the choice of surgical vs. conservative management. The size of the haematoma, rather than its location, and the degree of midline shift were the factors most influential in deciding in favour of surgical treatment, with a specificity of 0.83 and a sensitivity of 0.92. Conservative management of haematomas having a maximum thickness of less than 10 mm with a midline shift of less than 5 mm appears as safe. Outcome was "good recovery" in both the surgical and the nonsurgical patients, with only one death in the whole series, unrelated to the extradural lesion. This study focuses attention on a group of patients who are seldom examined by CT scan, but who can harbour potentially lethal lesions. Extension of CT scan examination to all adult patients with a minor head injury and a skull fracture can be recommended in order to identify significant haematomas in an asymptomatic phase.

Adolescent↗
PubMed1989

Rapid spontaneous disappearance of an acute extradural hematoma: case report.

The authors report the case of a patient presenting with an acute extradural hematoma and diffuse axonal injury. Control CT scan performed 4 hours later showed the complete resolution of the extradural collection together with increased evidence of shearing injuries. The mechanism of the hematoma resolution may probably be related to the concomitant acute brain swelling.

Accidents, Traffic↗