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A Zonta

Publications and source records attributed to A Zonta.

At least 37 records · Page 2Linked to original sources
PubMed1997

[Flexibility of the surgical model of intestinal transplantation in swine].

AIM: To verify the feasibility to introduce variations in the technique of intestinal transplantation, we developed three different intestinal transplant models in pigs. EXPERIMENTAL DESIGN: Feasibility and comparative study. ENVIRONMENT: Pre-clinical organ transplant surgery. MATERIALS AND METHODS: Sixty outbread piglets (mean weight 27.1 +/- 4.4 kg) received a total orthotopic intestinal allograft from equivalent donors perfused through the aorta with UW solution at 4 degrees C. Intraluminal flushing of the graft was always avoided. The animals were divided in 3 groups according to the transplantation procedure adopted. Group 1 (n = 9): excision of small and large bowel and replacement with small bowel only; group 2 (n = 39): excision of small bowel and its replacement; group 3 (n = 12): excision of small and large bowel and their "en-bloc" replacement. The superior mesenteric artery and vein were anastomosed end-to-end in all groups. RESULTS: The lowest perioperative mortality occurred in group 2 (28%), followed by group 3 (58%) and group 1 (78%). However, in group 1 the incidence of perioperative deaths was influenced by our learning curve in surgical and anesthesiologic management. No significant differences were noted in terms of cold and warm ischaemia time of the grafts, length of operative time, histopathologic analysis of preservation injury. The addition of the colon in the transplanted graft resulted in a more critical hemodynamic profile at reperfusion. CONCLUSION: Three different experimental models of intestinal transplantation are feasible in pigs. The choice can be made based on the type of study needed.

Analysis of Variance↗
PubMed1996

Combined immunosuppressive therapy with tacrolimus and mycophenolate mofetil for small bowel transplantation in pigs.

In a swine model of orthotopic small bowel transplantation, we assessed the efficacy of combined therapy with a low dose of tacrolimus plus mycophenolate mofetil, compared with high-dose tacrolimus monotherapy. The bowel was replaced in 25 piglets: group 1 (n = 5), no immunosuppression; group 2 (n = 10), tacrolimus, 0.3 mg/kg daily i.m. for 7 days, followed by b.i.d. oral doses to maintain blood levels of 15-25 ng/ml; and group 3 (n = 10), tacrolimus, 0.1 mg/kg i.m., in a single dose on day 0 and thereafter oral doses to maintain blood levels of 5-15 ng/ml, plus oral mycophenolate mofetil (10 mg/kg twice daily). Follow-up time was limited to 60 days. Median survival time as 11, 27, and > 60 days in groups 1, 2, and 3, respectively (P = 0.001). Survival rates were 0%, 40%, and 80% at 30 days and 0%, 0%, and 70% at 60 days in groups 1, 2, and 3, respectively (P = 0.03), group 1 vs. group 2; P = 0.003, group 1 vs. group 3; P = 0.02, group 2 vs. group 3). One animal in group 1 (20%) and two animals each in groups 2 and 3 (20%) died of technical complications. Rejection was the cause of death of 80% of animals of group 1 and of no animals in either group 2 or 3. None of the immunosuppressed animals developed clinical or histopathological evidence of graft-versus-host disease. Sixty percent of animals in group 2 (n = 6) and 10% in group 3 (n = 1) died from infections; two other animals in group 2 died of emaciation. The seven animals of group 3 that were alive at 60 days had immunosuppression stopped at that time. All died of rejection within 1 month. In conclusion, double-drug therapy with tacrolimus and mycophenolate mofetil consistently allowed extended survival after small bowel transplantation in swine, preventing or controlling acute cellular rejection without a high incidence of lethal complications related to overimmunosuppression.

Animals↗
PubMed1996

Evaluation of the reperfusion syndrome after liver ischemia in the rat.

Hepatic surgery in man often requires a transient interruption of the blood flow to the liver. After the vascular declamping the hepatic reperfusion induces a group of phenomena commonly called "reperfusion injuries." The aim of this study was to evaluate the presence and effect of vasoactive agents that could induce the acute pulmonary arterial hypertension which contributes to reperfusion injury. Wistar rats were used. The hepatic ischemia was induced by crossclamping the whole hepatic hilus for 20, 40, and 60 min. In control experiments a sham operation was performed. Blood samples were collected from the suprahepatic inferior vena cava. Strips of the main pulmonary artery were set up in an isolated organ bath and tested for the response to noradrenaline, adrenaline, KCl, and plasma samples. Plasma levels of catecholamines were determined by high-performance liquid chromatography. Plasma concentration of noradrenaline significantly increased from 1.6 +/- 0.4 (control) to 10.8 +/- 2.9 ng.ml-1 and adrenaline concentration rose from 2.7 +/- 0.7 to 38.7 +/- 7.6 ng.ml-1 after ischemia. Noradrenaline potency, compared to control values, significantly increased after prolonged liver ischemia. The plasma samples collected after prolonged liver ischemia caused a greater contraction of the pulmonary artery than from control plasma. This contraction is partially inhibited by phentolamine. We conclude that hepatic ischemia modifies the response of the pulmonary artery to exogenous noradrenaline. At the same time it induces an increase in the plasma levels of adrenaline and noradrenaline. The resulting combined effect may cause the pulmonary hypertension which has been observed in reperfusion injury.

Animals↗
PubMed1993

High-frequency perfusion fluorometry (HFPF): preliminary results on a new technique for assessing bronchial mucosa blood perfusion.

A new method for estimating airway mucosa blood perfusion is proposed. It is based on the use of a high-sensitivity perfusion fluorometer, which allows us to detect the first intravascular passage of injected fluorochromes. Total measuring time can be sensibly reduced with respect to standard perfusion fluorometry, allowing us to make assessments during fiberoptic bronchoscopy. In vitro studies were performed to set up the optical arrangement of the instrument. The optimal measuring distance (2.2 mm) between the probe tip and the fluorescent mucosa was established using a fluorescent film surface to simulate fluorescent mucosa. The depth of tissue layers involved in the fluorescence emission was assessed by positioning tissue sections of different thickness between the probe tip and the fluorescent film. Tissue layers at depths not exceeding 1200 microns were found to contribute to the fluorescence signal recorded by the instrument. Mucosa blood perfusion was evaluated in rat trachea, as a model, under three different experimental conditions of vascularization: (a) basal condition (BC), (b) partial devascularization (PD), (c) full devascularization (FD). Sodium fluorescein (diffusible into the interstice) and fluorescein isothiocyanate-dextran (not diffusible into the interstice) were used as fluorescent tracers. Under the BC both substances allowed us to detect the first passage of fluorochrome through the mucosa capillary network with the same accuracy. In PD the first pass peak disappeared; total emitted fluorescence decreased as well. In FD a flat tracing was recorded. Consistent results were obtained with both substances.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

[Hemodynamic changes in liver and multi-organ transplantation].

Multivisceral transplantation is a surgical technique developed as treatment for abdominal metastatic and/or multifocal malignancies. At present its clinical employment is reduced by our fragmentary knowledge of the intraoperative and postoperative outcome. The aim of this study is to compare intraoperative hemodynamic and respiratory changes during multivisceral transplantation (MTV, n = 12) and liver transplantation (OLTX, n = 14). The observations have been carried out a 4 phases: basal (I), visceral (II), reperfusion (III), final (IV). Phase I does not show differences between MTV and OLTX. In phase II MTV presents a lower temperature (T) and pulmonary arterial pressure (PAP) (p > 0.05). Phase III is marked by increasing T differences (p < 0.05), lower cardiac frequency (CF), pH and base excess (BE) (p < 0.05). PAP and cardiac output (CO) show a higher value in MTV (p < 0.05). Phase IV reports the vital signs close to normality in both groups, except pH in MTV (p > 0.05).

Animals↗
PubMed1992

Radioimmuno-guided endoscopy (RIGE) in the detection of primary and recurrent rectal tumor.

The usefulness of radioimmunoguided endoscopy in the detection of primary and recurrent rectal cancer was investigated. Of the 15 patients included in our study, 4 with suspected primary rectal cancer were examined preoperatively, while the remaining 11 were studied after radical resection of rectal carcinoma with the aim of detecting local recurrence. Radioimmunoguided endoscopy was performed employing a hand-held gamma-detecting probe (mod. 2 Oris, France), after the administration of a 111In labeled monoclonal antibody to CEA. Radioimmuno-guided endoscopy results detected the presence of primary or recurrent periluminal cancer in seven cases. In four it modified the preoperative stage based on the findings of conventional investigation and it influenced the surgical decision in five cases. No toxicity was noted and none of the patients developed HAMAs.

Adult↗
PubMed1992

[Choledochocele: a rare cause of chronic pancreatitis of the head of the pancreas].

The authors critically review the literature in order to ascertain the current state of knowledge regarding the anatomopathological, clinical and therapeutic characteristics of choledochocele, or cystic dilation of the terminal portion of the biliary tract. In particular, the Authors examine the etiopathogenetic aspects to explain how the presence of a choledochocele may lead to the onset of chronic pancreatitis. A clinical case which was recently brought to their attention is examined in detail. It concerns a 27-year-old patient in whom the presence of a large choledochocele had led to the onset of severe cephalopancreatitis which resisted all forms of treatment. In the case in question, ERCP played a decisive role in the diagnosis of the choledochocele, whereas ultrasonography, CT and selective arteriography were useful above all in relation to pancreatitis. In the case described ultraradical surgery, namely duodenocephalopancreatectomy, allowed the severe pancreatopathy and its etiological cause (choledochocele) to be efficaciously treated, confirming that this type of surgery currently plays an important role in the treatment of chronic pancreatitis.

Adult↗
PubMed1992

[Postoperative infections. A prospective analysis of 1396 cases].

Postoperative infections are the most frequent complications in surgery and are the commonest cause of the lengthening of hospital stay. The purpose of this study is to prospectively evaluate the incidence and predisposing factors of postoperative infections in 1396 surgical patients admitted to our Institute from 1984 to 1988. Patients undergoing minor surgical procedures (wound less than 2 cm) were excluded from the study. Patients were evaluated daily during hospital stay for onset of infections and results recorded on data sheet. Hemocultures in septic patients and samples of exudate at site of infection were taken whenever possible for aerobic and anaerobic cultures. 368 patients (26.36%) had at least one postoperative septic complication; (79 of them [5.65%] had two or more infections). The following infections were recorded: wound infections: 148 (10.60%); respiratory tract infections: 144 (10.31%); urinary tract infections 125 (8.95%); miscellaneous infections 11 (0.78%); thrombophlebitis 23 (1.64%); FUO 10 (0.71%). The most important predisposing factor for wound infection was endogenous contamination (wound infections: 18/499 [3.60%] in clean, 42/594 [7.67%] in potentially contaminated, 57/217 [26.26%] in contaminated and 31/86 [36.04%] in dirty operations). The duration of the anaesthesia was found to correlate with an increased incidence of respiratory tract infections (4.49% anaesthesia less than 60 min; 7.21% anaesthesia greater than 60 less than 120 min; 15.31% greater than 120 min anaesthesia). Urinary infections were more frequent when the patients where catheterized at least once in the postoperative period (24.86% vs 3.2%).

Fever of Unknown Origin↗
PubMed1991

Chromosome abnormalities in lymphocytes and fibroblasts of subjects with multiple endocrine neoplasia type 1.

A consistent degree of chromosome instability was found in cultured lymphocytes and in fibroblasts derived from skin biopsies of three patients with multiple endocrine neoplasia type 1 (MEN1). In both tissues, there was a significant increase in chromosomal breakage. Dicentrics and tricentrics, rings, translocations, deletions, acentric fragments, and presumptive double minutes were the most frequent abnormalities in lymphocytes. The fibroblasts of two patients had large clones consisting of trisomy 7 and trisomy 18 cells, respectively.

Adult↗
PubMed1990

The characterization of plasma-modified polydimethylsiloxane interfaces with media of different surface energy.

The effect of interfacing fresh pig blood with polydimethylsiloxane (PDMS) samples of different surface energies and chemistries is presented. PDMS-treated surfaces were obtained using oxygen plasmas. Aging in air produced rather hydrophobic surfaces, although less hydrophobic than the untreated one, due to hydrophobic recovery. Aging in water hindered it, therefore the surface remained hydrophilic. The concentration of albumin and fibrinogen was measured as a function of contact time with fresh pig blood with untreated, treated and aged in air, and treated and aged in water surfaces. The albumin concentration changed in a constant fashion. Fibrinogen depletion was observed for both treated surfaces. In the case of most hydrophobic surface a 'passivating layer' was formed. The same effect was not possible for the hydrophilic surface, due to the low albumin/fibrinogen-treated surface fracture energy.

Animals↗