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Biomedical subjects

G Azzena

Publications and source records attributed to G Azzena.

At least 19 recordsLinked to original sources
PubMed2006

Primary hyperparathyroidism related to a parathyroid adenoma: the dramatic clinical evolution of a misdiagnosed patient and its surgical solution.

Primary hyperparathyroidism is a clinical condition related to an excessive and abnormally regulated secretion of parathyroid hormone (PTH) from the parathyroid glands which is responsible for an alteration of the calcium and phosphorus metabolism. Parathyroid adenomas are the most important cause of primary hyperparathyroidism (80-85%). A case of parathyroid adenoma observed in a patient aged 47, admitted to the Emergency Medicine Department of our Hospital with a diagnosis of hypertensive crisis, cephalea, vomiting, and a clinical history of recurrent episodes of severe abdominal and renal pain, is presented. Lab data showed severe hypercalcemia and a progressive worsening of the renal function. A severe neurological involvement with stupor, derangement of mind, the arising of acute respiratory depression, lethargy compelled the colleagues to transfer him to the Intensive Care Unit; a neck ultrasonography showed a poor-echogenous area under the right thyroid inferior pole, with signs of vascularization. The suspect of a primary hyperparathyroidism related to a single adenoma of the parathyroid gland suggested a surgical treatment. A ''concise parathyroidectomy'' was performed. Our surgical approach was confirmed by the comparison of the preintervention and the post-intervention iPTH values: 2080 pg/mL (normal range: 12-65 pg/mL) before excision vs 101 pg/mL after the removal. The histologycal exam reported a parathyroid adenoma with large areas with haemorrage. Three days after surgery the patient was in good general conditions. Patients affected by primary hyperparathyroidism are often misdiagnosed because their clinical conditions can create differential diagnosis problems with other diseases. However the surgical option remains the gold standard treatment.

Adenoma↗
PubMed2003

[Carbon dioxide embolization: is it a complication of laparoscopic cholecystectomy? ].

The occurrence of pulmonary gas embolism in patients undergoing laparoscopic cholecystectomy is reported in the medical literature. Severe intraoperative complications or the patient's death were correlated to gas embolism during laparoscopic procedures. However, the careful retrospective study or the autoptic exam of such casualties have always showed an erroneus direct puncture of vessels or the straight insertion of the Veress needle into a parenchymal organ. It is obvious that the direct gas injection into a vein or into parenchymal organs is a primary cause of gas embolism, as well as the high flow insufflation of gas into the peritoneal cavity in concomitance with the lesion of major abdominal vessel's wall. Gas embolism may occur each time the vein internal pressure is lower than the external pressure and not only during a laparoscopic procedure when carbon dioxyde is inflated into the peritoneal cavity, but also during open surgery such as major liver resections, neurosurgery, vascular or cardiac surgery. The review of large series of laparoscopic cholecystectomies reported in the international literature, as well as our own clinical experience in this field, together with the results of laboratory animal studies based on the experimental insufflation or injection of carbon dioxyde, show that gas embolism must not be considered as a complication of laparoscopic surgery. Due to the above mentioned risks with the use of the Veress needle, the surgeon should revalue alternative means in creating the pneumoperitoneum.

Animals↗
PubMed2002

Early experiences with a porcine hepatocyte-based bioartificial liver in acute hepatic failure patients.

Orthotopic liver transplantation (OLT) is the only effective therapeutic modality in severe acute hepatic failure (AHF). The scarcity of organs for transplantation leads to an urgent necessity for temporary liver support treatments in AHF patients. A hepatocyte-based bioartificial liver (BAL) is under investigation with the main purpose to serve as bridging treatment until a liver becomes available for OLT, or to promote spontaneous liver regeneration. We developed a novel radial-flow bioreactor (RFB) for three-dimensional, high-density hepatocyte culture and an integrated pumping apparatus in which, after plasmapheresis, the patient's plasma is recirculated through the hepatocyte-filled RFB. Two hundred thirty grams of freshly isolated porcine hepatocytes were loaded into the RFB for clinical liver support treatment. The BAL system was used 8 times in supporting 7 AHF patients in grade III-IV coma, all waiting for an urgent OLT Three patients with no history of previous liver diseases were affected by fulminant hepatic failure (FHF) due to hepatitis B virus, 3 by primary non-function (PNF) of the transplanted liver, and one by AHF due to previous abdominal trauma and liver surgery. Six out of 7 patients underwent OLT following BAL treatment(s), which lasted 6-24 hours. All patients tolerated the procedures well, as shown by an improvement in the level of encephalopathy, a decrease in serum ammonia, transaminases and an amelioration of the prothrombin time, with full neurological recovery after OLT Our initial clinical experience confirms the safety of this BAL configuration and suggests its clinical efficacy as a temporary liver support system in AHF patients.

Adolescent↗
PubMed1999

Pancreatic beta-cell replication in streptozotocin-diabetic rats: the effect of liver compensatory growth on intraportally engrafted islets.

Early studies showed that compensatory liver growth after anterior portal branch ligation (aPBL) may restore normoglycemia in streptozotocin (STZ)-diabetic rats, in which a subtherapeutic islet mass was previously transplanted into the liver. We hypothesized that this effect could be related to islet regeneration at the graft site. This study was designed to characterize the proliferative response of the intraportally transplanted islets, shortly after aPBL. Male Wistar-Furth rats were used as syngeneic islet donors and/or recipients. STZ-diabetic rats were divided in four groups: groups 1 and 2 underwent selective 250-islet transplantation (Tx) into the posterior liver lobes, followed by aPBL 10 days later; rats were killed 24 h (n = 9) and 48 h (n = 10) after aPBL, respectively; groups 3 and 4 underwent selective 250-islet Tx into the posterior liver lobes, followed by sham aPBL 10 days later; rats were killed 24 h (n = 3) and 48 h (n = 3) after aPBL, respectively. Two hours before killing, all animals were injected with 5'-bromo-2'-deoxyuridine (BrdU; 50 mg/kg, i.v.). Liver sections were immunostained for insulin and BrdU, and both hepatocyte and islet cell labeling index (LI) were calculated. Islet cell LI was 2.30+/-1.18% in group 1, 2.23+/-1.00% in group 2, 0.43+/-0.29% in group 3, and 0.39+/-0.21% in group 4 (group 1 vs. group 3: p<0.02; group 2 vs. group 4: p<0.01). Hepatocyte LI was 2.50+/-2.14% in group 1, 15.0+/-7.6% in group 2, 0.12 +/-0.04 in group 3, and 0.11+/-0.03% in group 4, respectively (group 1 vs. group 2: p<0.02; group 1 vs. group 3: p<0.001; group 2 vs. group 4: p<0.001). Our study showed that intraportally transplanted islets undergo a concurrent proliferative response after aPBL, although with a lower extent and a different timing when compared with the liver-cell response.

Animals↗
PubMed1998

In vitro morphological and functional characterization of isolated porcine hepatocytes for extracorporeal liver support: bile acid uptake and conjugation.

Recently, researchers have focused on the use of bioartificial liver (BAL) to support patients with fulminant hepatic failure (FHF). We have developed a cell-based BAL, consisting of porcine hepatocytes in a hollow-fiber bioreactor. To better characterize BAL metabolic functions in vitro, bioreactors were inoculated with 48-h-cultured, microcarrier-attached hepatocytes and perifused with recirculating human plasma that contained either 1 microCi of [24-14C] plasma-enriched cholate or 1 microCi of [24-14C] plasma-enriched taurocholate. Bile acids were sampled hourly and separated into four fractions (unconjugated, glycoconjugated, tauroconjugated, and sulfated) for radioactivity determination. Following 3 h perifusion, the glycoconjugated and sulfated bile acid fractions in the bioreactor extrafiber space were significantly elevated when compared to the recirculating plasma. During perifusion with taurocholate-enriched plasma, a relative decrease in the tauroconjugated fraction and an increase in the glycoconjugated fraction were observed. Cholate was accumulated by hepatocytes to a level threefold lower than taurocholate; however, a significant proportion of radioactivity (<25%) was detected in the glycoconjugated fraction. Ultrastructural examination of microcarrier-attached hepatocytes illustrated that the features typical of metabolically active liver cells were maintained. Our data demonstrate the ability of BAL to clear bile acids from the circulation, to accumulate cholate and taurocholate, and to conjugate a substantial amount of cholic acid.

Animals↗
PubMed1998

Growth of intraportally transplanted islets under liver regeneration stimulus and restoration of normoglycemia in streptozocin-diabetic rats.

BACKGROUND: Limitation of beta-cell growth after intraportal islet transplantation plays an important role in graft failure. To induce transplanted beta-cell proliferation, we studied the effect of compensatory liver growth in diabetic rats that had a subtherapeutic islet mass previously injected into the liver. METHODS: Syngeneic rats were used as islet donors or recipients; diabetes was induced by streptozocin. Three groups of streptozocin-treated rats were studied. In group 1, 250 islets were selectively transplanted into the posterior liver lobes and 10 days later anterior portal branch ligation (PBL) was performed (n = 18); in group 2, 250 islets were transplanted into the posterior lobes and 10 days later sham PBL was performed (n = 13); in group 3, rats underwent a sham transplantation and PBL (n = 6). Nonfasting blood glucose levels and body weight were monitored. Six rats in groups 1 and 2 were killed 48 hours after PBL, liver sections were stained for proliferating cell nuclear antigen, and islet cell labeling index was calculated. The remaining rats were killed 30 days later. Liver compensatory growth or atrophy was calculated and morphometric determination of beta-cell area was assessed on insulin-immunostained sections of the liver. RESULTS: In group 1 rats killed 48 hours after PBL, islet cell labeling index was significantly higher than in group 2 (p < 0.0001). After PBL, we observed normalization of nonfasting blood glucose levels in 10 of 12 rats. At 30 days, posterior liver lobes showed compensatory growth (218.5% +/- 18.6%) accompanied by atrophy of the anterior lobes; morphometric study of liver-engrafted islets showed a significant increase of individual beta-cell area, compared with group 2 (p < 0.0001). In groups 2 and 3, normoglycemia was not achieved. CONCLUSIONS: In streptozocin-diabetic rats, normoglycemia was restored after transplantation of a sub-therapeutic islet mass, followed by PBL-induced liver regeneration. Histologic and morphometric results indicating islet cell proliferation suggest that compensatory liver growth might have induced a hypertrophic/hyperplastic response in the intraportally transplanted beta-cells.

Animals↗
PubMed1997

Technetium-99m sestamibi leg scintigraphy for non-invasive assessment of propionyl-L-carnitine induced changes in skeletal muscle metabolism.

Carnitine derivatives, such as propionyl-l-carnitine (PLC), have been shown to improve walking distance in patients with obstructive peripheral artery disease (PAOD). The aim of this study was to ascertain whether technetium-99m sestamibi leg scintigraphy may be a useful tool in the evaluation of changes in skeletal muscle metabolism induced by chronic therapy with PLC. Twenty patients with clinical and instrumental evidence of PAOD were randomly assigned to a 3-month period of therapy with either PLC or placebo. Rest 99mTc-sestamibi leg scintigraphy and echo-Doppler sonography were performed on all subjects immediately before and upon completion of the treatment period. At the end of the protocol the following results were observed in patients who underwent PLC administration: (a) a significant increase in both thigh and calf 99mTc-sestamibi uptake, in comparison with baseline values (P<0.001); (b) the absence of statistically significant modifications of Doppler blood flow indices of the lower limbs. In conclusion, after chronic administration of PLC, a significant increment in skeletal muscle uptake of 99mTc-sestamibi was demonstrated without any apparent change in regional blood flow. This fact, if proven in further studies, may suggest a role for this tracer as a non-invasive probe of tissue bioenergetics.

Arterial Occlusive Diseases↗
PubMed1993

Efficacy and safety of the stepped care medical treatment of ascites in liver cirrhosis: a randomized controlled clinical trial comparing two diets with different sodium content.

In order to clarify debated issues of the medical treatment of ascites in cirrhosis--the usefulness of a low sodium diet and washout period preceding diuretic administration, maximal dosage of antimineralocorticoid to be reached before the addition of a loop diuretic, identifications of factors influencing treatment efficacy--115 hospitalized patients with non-azotemic cirrhosis and ascites were recruited and randomized to receive a diet providing either 40 or 120 mmol of sodium daily. After a washout period from the outpatient diuretic regimen for 7 days (Step 1), increasing dosages of K-canrenoate (200 mg/day every 4th day up to 600 mg) were administered to patients not undergoing spontaneous diuresis (Step 2). Upon the failure of Step 2, K-canrenoate (400 mg/day) and furosemide at increasing dosage (25-50-100 mg every other day) were given (Step 3). Nine percent of patients underwent spontaneous diuresis, and 77% developed a negative sodium balance by the end of Step 2 (69% with a dosage of K-canrenoate < or = 400 mg/day) and 93% by the end of Step 3. Two patients were withdrawn from the protocol due to diuretic side-effects. Univariate analysis showed that the type of diet did not influence the response to treatment. The washout period led to a significant increase in endogenous creatinine clearance; natremia significantly rose in hyponatremic patients. Multivariate analysis showed that creatinine clearance and plasma aldosterone were independent predictive factors of the response to treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Ascites↗
PubMed1992

Thromboxane-receptor blockade increases water diuresis in cirrhotic patients with ascites.

This study was undertaken to investigate the role of increased renal thromboxane (TX) A2 production in modulating renal hemodynamics and sodium and water retention in cirrhotic patients with ascites. In a randomized, double-blind, placebo-controlled, crossover trial, 15 nonazotemic cirrhotic patients with ascites and elevated urinary TXB2 excretion received the thromboxane-receptor antagonist ONO-3708 (3 micrograms.kg-1.min-1) in a 4-hour continuous infusion. Administration of ONO-3708 significantly blocked TXA2 receptors; bleeding time showed a twofold increase (432 +/- 65 vs. 131 +/- 17 seconds; P less than 0.005), and platelet aggregation to U-46619 (an agonist of TXA2 receptors) was abolished in all patients studied. The drug induced a significant increase in free water clearance (3.06 +/- 0.70 vs. 1.72 +/- 0.57 mL/min; P less than 0.001) and diuresis (4.74 +/- 0.79 vs. 3.94 +/- 0.66 mL/min; P less than 0.05) compared with placebo, as well as a significant (14%) increase in renal plasma flow. The increases in both free water clearance and diuresis induced by ONO-3708 were directly related to basal urinary TXB2 excretion. These results suggest a role for renal TXA2 as a modulator of water handling in cirrhotic patients with ascites.

Aged↗
PubMed1991

Comparison of the effects of torasemide and furosemide in nonazotemic cirrhotic patients with ascites: a randomized, double-blind study.

In a randomized double-blind trial we compared the effects of torasemide, a new loop diuretic, and furosemide in nonazotemic cirrhotic patients with ascites during a 3-day period in association with potassium canrenoate (200 mg/day) administration. Doses of loop diuretics administered in this trial (10 and 25 mg/day of torasemide and furosemide, respectively) had been shown to be equipotent in healthy subjects. Torasemide induced significantly greater natriuresis than furosemide (p less than 0.02), with a twofold greater percentage increase in basal values (day 1: 130% vs. 50%; day 2: 104% vs. 42%; and day 3: 65% vs. 26%, respectively). Body weight loss was significantly higher during torasemide (p less than 0.02) administration, and the overall decrease at the end of the treatment was twice as high for furosemide (2.5 +/- 0.6 kg vs. 1.3 +/- 0.4 kg, respectively). Diuresis was also higher during torasemide administration, but the difference was not significant (p = 0.08). The extent of kaliuresis observed during the two treatments was almost identical despite the striking differences in the natriuretic response. The effects of the two treatments on plasma electrolytes, creatinine clearance, blood urea nitrogen, mean arterial pressure, heart rate and plasma arginine vasopressin concentration were similar. Both drugs caused increases in plasma renin activity at the end of the treatment, whereas plasma aldosterone concentration slightly increased only after torasemide administration. Despite the presence of a trend toward a more pronounced effect on these parameters after torasemide administration, no significant difference between the two treatments was observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Ascites↗
PubMedDate not supplied

Arteriovenous fistulas for hemodialysis created using a long-term absorbable suture: a safe solution and a measure to minimize myointimal hyperplasia.

BACKGROUND/AIMS: The goal of the therapeutic management of patients affected by end-stage renal disease (ESRD) is to maintain the vascular access (VA) as long as possible. Myointimal hyperplasia development in the vascular walls of arteriovenous fistulas (AVFs) is considered one of the most important factors responsible for procedure failure. These alterations could be linked to hemodynamic changes in the anastomosis and to the presence of the surgical suture itself. We report our preliminary experience, discussing the use and the possible benefits of an absorbable suture in polyglycolide trimethylene carbonate (PTC) in AVF creation. METHODS: Seventy-four AVFs were created as primary access for hemodialysis (HD), using PTC, over 4 years. Age, gender, ESRD etiology, artery and vein preoperative diameters, AVF survival outcome, and the number of AVFs created per year were recorded. The Kaplan-Meier method was used to analyze AVF survival rates. RESULTS: No dehiscences, pseudoaneurysms, or failures in the 'critical' period related to PTC absorption were recorded. Kaplan-Meier analysis was used to evaluate AVF survival; 12-month primary AVF survival (74.33%) and AVF failure (25.67%) rates, 9 'early' (8.22%) and 10 'late' failures (13.51%), and a 360-day mean survival were found. CONCLUSIONS: Our data indicate that PTC, a well known and widely used material for sutures in vascular surgery, is safe and effective in AVF creation. Potential advantages of PTC sutures are represented by a reduced myointimal hyperplasia formation in the AVF vascular walls, prolonging the AVF lifespan and avoiding re-interventions.

Journal Article↗