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Biomedical subjects

G Porcelli

Publications and source records attributed to G Porcelli.

At least 19 recordsLinked to original sources
PubMed1997

Placement of long-term central venous catheters in outpatients: study of 134 patients over 24,596 catheter days.

OBJECTIVE: Our goal was to investigate the feasibility of inserting long-term central venous access devices in outpatients using a simple technique that minimizes the risks of complications linked to venipuncture and errors in management. MATERIALS AND METHODS: We placed 147 central venous catheters (CVCs) in 134 patients under local anesthesia. No sedation was used, and all procedures were done in our radiology department. Of the 134 patients, 101 patients were included in the follow-up. Overall follow-up of patients was 24,596 catheter days (mean, 243.52 days). Percutaneous access, mostly by the subclavian vein, was done by micropuncture technique under fluoroscopic guidance. Six CVCs were untunneled, 36 were connected to totally subcutaneous ports, and 105 were tunneled. RESULTS: The only immediate complication was pneumothorax (3%). Late complications, expressed per 1000 catheter days, included CVC breakage (0.12), vascular thrombosis (0.08), catheter occlusion (0.04), dislodgment (0.24), and local or systemic infections (0.40). CONCLUSION: Outpatient CVC placement is feasible because the procedure is not adversely affected when the patient is not hospitalized. The drawbacks are identical to those faced by inpatients. Improved materials and more extensive information on the management of patients with long-term CVCs would help reduce complications further.

Ambulatory Care↗
PubMed1994

Renal toxicity and arterial hypertension in rats chronically exposed to vanadate.

The effects of 1, 10, or 40 micrograms/ml of vanadium, given for six or seven months as sodium metavanadate in drinking water on cardiovascular and biochemical variables and the electrolyte metabolism of male Sprague-Dawley rats were investigated. At the end of the exposure period, all animals exposed to vanadate had increased systolic and diastolic blood pressure. This effect was not dose dependent and heart rate and cardiac inotropism were not affected. The role of defective renal function and electrolyte metabolism in such effects was supported, in the rats exposed to 10 and 40 ppm of vanadium, by the following changes: (a) decreased Na, + K(+)-ATPase activity in the distal tubules of nephrons; (b) increased urinary excretion of potassium; (c) increase in plasma renin activity and urinary kallikrein, kininase I, and kininase II activities; (d) increased plasma aldosterone (only in the rats treated with 10 ppm of vanadium). The alterations in the rats exposed to 1 ppm of vanadium were: (a) reduced urinary calcium excretion; (b) reduced urinary kallikrein activity; (c) reduced plasma aldosterone. These results suggest that blood hypertension in rats exposed to vanadate depends on specific mechanisms of renal toxicity related to the levels of exposure.

Animals↗
PubMed1993

Urinary kallikrein excretion in type 1 (insulin-dependent) diabetes mellitus.

Kidney haemodynamics appear to change after the early phases of diabetic nephropathy: increases in glomerular filtration rate and in renal plasma flow have been widely reported, while kidney size is increased. As the renal kallikrein-kinin system has been demonstrated to regulate kidney blood circulation, we have evaluated the excretion of urinary kallikrein in 87 Type 1 (insulin-dependent) diabetic patients with and without hyperfiltration. Urinary kallikrein excretion was measured in 24-h urine collections. The esterolytic activity was determined by fluorimetric assay. The excretion of urinary kallikreins was significantly higher in hyperfiltering patients (472 +/- 125 esterase units/24 h) than in normofiltering (168 +/- 77 esterase units/24 h) and control subjects (151 +/- 39 esterase units/24 h), p < 0.001. Furthermore, we observed a positive correlation between urinary kallikrein excretion and glomerular filtration rate (r = 0.785). These data suggest that variations of kallikrein and kinin concentrations may play a role in the alteration of renal haemodynamics in Type 1 diabetes. It is possible that the kinin-kallikrein system, the renin-angiotensin system and the prostaglandins may interact to determine the haemodynamic alterations which are present in the diabetic disease.

Adult↗
PubMed1992

Localization and characterization of human salivary kininases.

The human saliva of normal subjects containing large amounts of basic carboxypeptidase produces decarboxylated non inflammatory peptides, for instance, kinins and anaphilotoxins C3a, C4a and C5a. A reduction of epithelial cell-bonded enzyme (carboxypeptidase M-type or kininase I), produces inflammations by the active intact kinins and the initiation of the alternative activating pathway of complement by active anaphilotoxins, which generate complement cleavage products, containing potential destructive mechanism.

Complement System Proteins↗
PubMed1992

Renal mechanisms in the cardiovascular effects of chronic exposure to inorganic mercury in rats.

Male weanling Wistar rats received 200 micrograms/ml of mercury (Hg), as HgCl2, in drinking water for 180 days. At the end of the treatment, systemic arterial blood pressure was augmented, cardiac inotropism was reduced, and heart rate was unchanged. Light and electron microscopical studies of the kidney showed a mesangial proliferative glomerulonephritis in about 80% of the glomeruli. Tubular cells showed reduction of the acid phosphatase activity, which was related to functional abnormalities of the lysosomes. In the 24 hour urine samples of the Hg exposed rats, there was slight reduction of kallikrein activity, but evident proteinuria was not present in all samples. Plasma renin activity was reduced, that of angiotensin I-converting enzyme was augmented, and plasma aldosterone concentrations were unchanged. Mercury was accumulated mostly in the kidney of the Hg treated animals; and the content of Hg in the heart was higher than in the brain. These data show that chronic exposure to Hg acts on the kidney with complex mechanisms of toxicity; these contribute to modify systemic haemodynamics.

Animals↗
PubMed1992

Kallikrein-kinin,enkephalin, renin-aldosterone and catecholamine systems in the vanadate (as vanadyl)-induced arterial hypertension.

Exposure to vanadate was found to induce arterial hypertension through effects on renin-angiotensin-aldosterone, renal peptidergic, and central and peripheral catecholaminergic systems. Vanadate increased, mainly in vascular myocells, both receptor-operated Ca2+ channel- and cyclic-AMP-dependent availability of Ca2+ for contractile processes. Vanadate was selectively accumulated by tissues in the +4 oxidation state (vanadyl).

Aldosterone↗
PubMed1992

[Combined use of real-time digital subtraction radioscopy and computerized tomography: potential advantages in diagnostic and interventional radiology].

The idea of combining fluoroscopy and CT arose from the daily practice in diagnostic and interventional radiology. A Diasonics OEC high-performance image intensifier complete with a digital subtraction system was connected to a Siemens Somatom-DRH CT scanner to work in tandem. CT is used for a localization in-depth and fluoroscopy for the subsequent maneuvers within an organ or body compartment. With this combination, complex procedures such as transarterial portography, percutaneous embolizations, pain treatment and manipulation for catheterization of the bile ducts and urinary tract could be performed in one place and in one session. CTF is especially useful when patients should not be moved about from room to room or undergo an examination in several sessions, as it happens with children or critically ill or contagious patients.

Adult↗
PubMed1989

Physiologic role of the peripheral enkephalinergic system in regulating cardiovascular homeostasis: evidence of interactions with the renin-angiotensin and kallikrein-kinin systems.

On isolated heart preparation, it was found that Leu5-Enkephalin (Leu5-ENK) did not influence the cardiac function. On the other hand, Leu5-ENK induced a specific dose-related inhibition, in the cardiac perfusate, of the activities of kininase II (KII) and angiotensin converting enzyme (ACE) (but not of kininase I-KI). Instead no detectable alterations of the above enzymatic activities with the used concentrations of Leu5-ENK were observed in vitro. This opioid also increased specifically the effects induced by some of the autacoids, related to both renin-angiotensin and kallikrein-kinin systems, on the KII and ACE activities. A specific correlation between these Leu5-ENK-induced modifications and the functional responses of the heart to the same autacoids was observed. Naloxone (NAL) and more significantly ICI 174864 (ICI) opposed or reversed the inhibitory effect of the used opioid whereas they had neither inhibitory nor synergic effect on both KII and ACE activity by themselves. The possible physiologic role of the enkephalins in regulating cardiovascular function by acting peripherally on some humoral systems through modulatory mechanism was discussed.

Animals↗
PubMed1987

Kininase I, kininase II and aminopeptidase levels in patients with gastrointestinal tumors.

Some indices of the kallikrein kinin system, namely kininase I (KI), kininase II or angiotensin converting enzyme (KII-ACE) and phenylalanine-arginine aminopeptidase (AP) were analyzed, to detect their levels in ten selected normal subjects and in 20 selected patients with colonic (n = 8) and gastric adenocarcinoma (n = 12). While AP and KI levels did not show differences in the groups under analysis, KII values showed a significant difference (P +/- 0.01), present since the early stages of the diseases and unrelated to the normal laboratory indices.

Adenocarcinoma↗
PubMed1986

Urinary kallikrein and kininase activity in normal and complicated by hypertension pregnancy.

Kallikrein and kininase activities were determined in urine of 58 hospitalized pregnant patients: 15 with E.P.H. gestosis, 10 with chronic hypertension, 18 with non proteinuric pregnancy induced hypertension, 15 with no hemodynamic disease as controls. All our cases with hypertension were treated with alpha-methyl-dopa. A significant increase in urinary kininase activity was shown by only E.P.H. gestosis group vs. controls. In the same group we found a significant decrease in urinary kallikrein activity vs. controls, in contrast with the results obtained previously, perhaps because of the different measuring method. The kininase/kallikrein ratio, theoretically indicative of kinins activity, increased significantly only in the E.P.H. gestosis group.

Blood Pressure↗