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Biomedical subjects

M Zambelli

Publications and source records attributed to M Zambelli.

At least 19 recordsLinked to original sources
PubMed2005

Orthotopic liver transplantation for biliary atresia.

Biliary atresia (BA) represents the most frequent indication for liver transplantation (OLTX) in the pediatric population. The aim of this paper was to present a series collected over the last 7 years from October 1997 through July 2004, including 260 pediatric OLTX in 231 patients. BA was the indication in 137 patients. There were 69 boys and 68 girls of mean weight 10.68 kg and median age 0.9 years. As a primary transplant, 99 patients received a LLS graft; 27 a whole graft; four a I+IV-VIII segment, and two a I-IV segment. Mean follow up was 1047 days (range, 1-2496 day). Infections were diagnosed in 45 patients, vascular complications in 27 patients. Surgical complications that required reintervention occurred in 25 patients. In 41 cases biliary complications occurred, 11 requiring reintervention. 16 patients were retransplanted. In two cases another re-OLTx was performed. Currently 126 patients are alive, showing an actuarial 1 year survival of 92% and 5 year 91%, with actuarial graft survivals of 85% at 1 year and 82% at 3 and 5 years. Our results confirm the effectiveness of OLTx for the treatment of children with BA and a failed Kasai procedure. Split liver grafts represent an excellent organ supply for these patients, achieving optimal results with no mortality on the waiting list.

ABO Blood-Group System↗
PubMed2005

Early portal vein thrombosis after pediatric split liver transplantation with left lateral segment graft.

Early portal vein thrombosis (PVT) represents a serious complication after liver transplantation (OLTx). From October 1997 through July 2004, 260 OLTx were performed in 231 children, including 189 of left lateral segments (LLS). We retrospectively analyzed the incidence and the outcome of early PVT in this group. A daily doppler US scan was performed during the first week after transplantation. Early PVT occurred in 14 patients (8%), 10 males and four females of median age 0.77 years. The main indication for primary transplantation was biliary atresia (10), followed by Byler's disease (2), acute liver failure on cryptogenetic cirrhosis (1), and Alagille syndrome (1). Four children underwent retransplantation; three cases of thrombectomy and revision of the anastomosis, two children were treated with beta blockers, one of whom had a later failed attempt at percutaneous revascularization and eventually a meso-caval shunt. Five patients were followed with observation and no treatment. Among the four patients who died, three were in the retransplantation group and one in the thrombectomy and revision of the anastomosis group; the overall mortality was 28%. With a median follow up of 399 days, 10 patients are alive with an actuarial survival at 1 and 5 years of 72%, and graft survival rates at 1 and 5 years of 64%. PVT represents a serious complication after pediatric OLTx with LLS grafts. Prompt detection and aggressive surgical treatment in selected cases are required to reduce the mortality and graft loss.

Cadaver↗
PubMed2005

Orthotopic liver transplantation for alagille syndrome.

Alagille syndrome (AS) is a dominantly inherited, multisystem disorder involving the liver, heart, eyes, face, and skeleton. From October 1997 through July 2004, 260 pediatric orthotopic liver transplantations (OLTx) were performed in 231 patients. This report describes 21 patients of median age 1.95 years (range, 0.7-16.7) who had alagille syndrome. We present the technical features of the OLTx, incidence and type of complications, medical conditions related to the syndrome, need for retransplantation, as well as patient and graft survival rates. A split liver technique was used in 16 patients (76%) who received a left lateral segment (LLS) graft whereas 7 patients (33%) received a whole liver. Only cadaveric donors were used. The major surgical complications requiring reintervention in 11 patients (52%) included biliary problems (19%) and vascular complications (17%). One case of hepatic artery thrombosis required retransplantation. Three recipients (14%) died. All other patients are alive with an actuarial survival rate of 90% at 1 year and 80% at 5 years. The actuarial graft survival rate is 85% at 1 year and 75% at 5 years. Patients with AS, despite the associated cardiovascular anomalies, can be treated successfully by a combined approach between cardiologist, radiologist, cardiothoracic, and liver transplant surgeons. With careful planning and operative management, the results are comparable with those obtained with other more common cholestatic diseases.

Actuarial Analysis↗
PubMed2005

Transplantation for acute liver failure in children.

We reviewed the clinical data of 30 children-hospitalized for acute liver failure in the last 6 years. Ten patients were not listed for liver transplantation OLTX. Their clinical conditions gradually improved and they are all alive without deficit. Among 20 patients listed, 15 underwent urgent OLTX. Two children died on the waiting list and three were suspended from waiting list after few days because of improvement. Survival according to age class was analyzed dividing the patients into two groups: A, age 1 year or less versus B, age between 1 and 16 years. The patient survival was 86% at 6 months and 61% both at 1 and 2 years. Survival at 6 months and 1 and 2 years was 88%, 67%, and 45% for the patients in group A and 83%, 83%, and 83% for the patients in group B (P = NS). Observing graft-to-recipient weight ratio and donor-to-recipient weight ratio most patients received an optimal sized graft. The split-liver technique is considered the preferred method of liver transplantation even in the pediatric patients with acute liver failure; especially in the setting of a cooperative system in which all livers that are suitable for split-liver transplantation are shared between centers. In order to have the best chance for survival, children with acute liver failure should be referred as soon as possible to an highly specialized pediatric liver transplantation center that can offer all the treatment modalities that are currently available.

Adolescent↗
PubMed2005

Use of extended right grafts from in situ split livers in adult liver transplantation: a comparison with whole-liver transplants.

INTRODUCTION: We report our experience of in situ split-liver transplantation (SLT) for adult patients and compare the results with those achieved with whole-liver transplantation (WLT). METHOD: From November 1997 to December 2003, 109 liver transplantation were performed in 104 adult patients including 90 WLT (83%) and 19 SLT (17%) grafts. Fifteen extended right grafts (ERG, segments I + IV to VIII) were obtained with in situ split-liver procedures, generating also left lateral segment grafts, which were transplanted at our institution or elsewhere. Four left lobe (LL, segments I to IV) and right lobe (segments V to VIII) grafts were obtained by a modified in situ procedure for adult recipients. UNOS status, percentage of primary or secondary transplantation, and underlying liver disease were similar among patients receiving whole versus split grafts. Donors were older in whole than ERG cohorts (53 vs 26 years, P < .001). Procurement parameters and intraoperative profiles of transplant procedure were comparable among the groups. RESULTS: Median follow-up was 18 months (range: 1 to 73). Four patients with whole (4%) and no patient with ERG underwent retransplantation (P = NS). One- and 3-year patient survivals were 86% and 79% with WLT versus 93% and 93% with ERG (P = NS). One- and 3-year graft survivals were 84% and 75% with WLT versus 93%, and 93% with ERG (P = NS). Incidence of vascular complications was 8% with WLT, 13% with ERG (P = NS). The incidence of biliary complications was 13% in WLT, 27% in ERG (P = NS). CONCLUSIONS: The use of ERG from in situ split livers for adult transplantation allowed us to obtain results comparable or even better than those obtained with WLT. Split-liver transplantation is an effective, safe mechanism to expand the cadaveric donor pool.

Adult↗
PubMed2005

Orthotopic liver transplantation for Byler's disease.

In this study we analyzed the features of 12 patients who underwent liver transplantation for progressive familial intrahepatic cholestasis (Byler's disease [BD]) in view of the technical features of the OLTx, incidence and type of complications, need for retransplantation, as well as patient and graft survivals. BD was the indication in 12 patients of median age 1.32 years and median weight 10 kg. Median follow-up was 670 days. Major surgical complications requiring reintervention occurred in three patients. No thrombosis of the hepatic artery was observed. Infections with positive blood cultures were diagnosed in four patients. One patient had a biliary anastomotic stenosis successfully treated by percutaneous techniques. Four patients had episodes of acute rejection treated with steroids. Two patients were retransplanted, both of whom died in the early postoperative period due to hepatic vein thrombosis and venoenteric fistula. The actuarial patient and graft survival was 83% at 1 year and 83% at 5 years. Split-liver grafts represent an excellent organ supply for these patients, achieving good results with no mortality on the waiting list.

Adolescent↗
PubMed2001

Mesenteric and renal oxygen transport during hemorrhage and reperfusion: evaluation of optimal goals for resuscitation.

BACKGROUND: Changes in flow to the gut and the kidney during hemorrhage and resuscitation contribute to organ dysfunction and outcome. We evaluated regional and splanchnic oxygen (O2) flow distribution and calculated oxygen supply distribution during hemorrhage and reperfusion and compared them with global measures. METHODS: Seven anesthetized pigs were instrumented to evaluate global hemodynamics, visceral blood flow, and oxygen transport. Tonometric pH probes were positioned in the stomach and jejunum. Animals were bled to 45 mm Hg for 1 hour. Crystalloids and blood were infused during the following 2 hours to normalize blood pressure, heart rate, urine output, and hemo- globin. RESULTS: During hemorrhage, mesenteric flow and O2 consumption were significantly decreased, whereas systemic consumption remained normal. Renal flow was reduced, but renal O2 consumption remained normal. After resuscitation, despite normal hemodynamics, neither systemic, mesenteric, nor renal O2 delivery returned to baseline. Lactate remained significantly increased. Arterial pH, base excess, and gastric and jejunal pH were all decreased. CONCLUSION: During hemorrhage, the gut is more prone than other regions to O2 consumption supply dependency. After resuscitation, standard clinical parameters do not detect residual O2 debt. Lactate, arterial pH, base excess, and intramucosal gut pH are all markers of residual tissue hypoperfusion.

Acid-Base Equilibrium↗
PubMed2000

Intravenous inotropic agents in the intensive therapy unit: do they really make a difference?

Part of the management of refractory heart failure is treatment aimed at preventing organ damage due to inadequate oxygen delivery, improving hemodynamics, and maximizing cardiac output while maintaining only mildly elevated ventricular filling pressures The aim of this paper is to review the most updated indications on intravenous inotropic agents, and to compare their cardiac and peripheral effects. Finally, clinical implications of their use (alone or in combination) are reviewed.

Adrenergic beta-Agonists↗
PubMed2000

Complications and long-term outcome of 80 oncology patients undergoing needle catheter jejunostomy placement for early postoperative enteral feeding.

Some findings suggest that needle catheter jejunostomy (NCJ) is associated with a significant rate of potentially dangerous complications. The purpose of this study was to prospectively evaluate the rate and type of early and late complications associated with NCJ in patients with surgical treatment of upper gastrointestinal malignancy. Eighty patients underwent NCJ implant at the end of their scheduled surgical procedure. Enteral nutrition programme was started on postoperative day 1 in the surgical ICU. NCJ was always removed in the outpatient clinic after hospital discharge. One case of tube blockage has been observed as single short-term complication in this series. No long-term complications have been detected after a mean follow-up of 12 months. Routine use of NCJ in malnourished patients undergoing major surgical procedures on upper gastrointestinal tract is safe and effective.

Adolescent↗
PubMed1999

Thoracodorsal artery as a free graft for coronary artery bypass grafting.

Arterial myocardial revascularization using different arterial conduits as mammary, radial, gastroepiploic, subscapular and epigastric arteries are well documented. This report describes a preparation and use of thoracodorsal artery as a free graft for coronary artery bypass grafting. The preparation and removal of thoracodorsal artery were performed through right axilla. The artery was used as a free conduit for left anterior descending artery (LAD) in a 58-year-old female for the second revascularization. The saphenous veins, mammary arteries, right radial artery and epigastric artery were not available. The perioperative course was uneventful and we can recommend the graft as an alternative for such cases.

Coronary Artery Bypass↗
PubMed1994

Restoration of gait with orthoses in thoracic paraplegia: a multicentric investigation.

Twenty-eight patients with complete T3-12 traumatic paraplegia were fitted with hip guidance orthosis (HGO, four cases), reciprocating gait orthosis (RGO, 13 cases) or advanced reciprocating gait orthosis (ARGO, 11 cases). Patients were enrolled for 2 months-6 years (median 5 months) in six Italian rehabilitation centres engaged in a common prospective protocol, including a 6 month follow up. After 12-84 (median 20) rehabilitation sessions over a 3-16 week (median 7) period of specific training all of the patients could perform don-doff manoeuvres autonomously in 2.5-15 min (median 6.4), and could walk at least 30 m with a walker (15 cases) or forearm crutches (13 cases) at 10-50 cm/s (median 16.6). HGO patients tended to walk more slowly than the others. None of them could walk upstairs, while three out of 13 RGO patients and seven out of 11 ARGO patients could. Six months later, 21 patients still used the orthosis for 0.5-3 h daily (median 2). Only four patients used the orthosis to walk outdoors. As a median they could still attain the speed recorded at discharge. Six patients had decided to abandon the device, while one was wheelchair bound due to a recent spinal intervention. Neither clinical, demographic or locomotor variables, nor centre and type of orthosis appeared to be predictive of abandonment of the device. During either the training or the follow up periods, six out of 13 RGO and seven out of 11 ARGO had to be repaired by the orthotist 1-10 times (median 3). Thus, in our sample of paraplegics, walking with these orthoses appeared to be a promising form of exercise rather than an alternative to wheelchair locomotion.

Adolescent↗
PubMed1994

Serotonergic facilitation of acetylcholine release in vivo from rat dorsal hippocampus via serotonin 5-HT3 receptors.

The serotonin (5-HT) releaser d-fenfluramine and its active metabolite d-norfenfluramine, or the 5-HT-uptake inhibitor citalopram, by increasing synaptic 5-HT availability, facilitated in vivo release of acetylcholine (ACh) from dorsal hippocampi of freely moving rats as determined by the microdialysis technique. The effects of d-norfenfluramine (7.5 mg/kg i.p.) and citalopram (10 microM, applied by reverse dialysis) were prevented by a 14-day chemical lesion of the raphe nuclei, suggesting mediation by the 5-HT system in the cholinergic action of the drugs. The increase in extracellular ACh content induced by d-norfenfluramine (5 mg/kg i.p.) was antagonized by the 5-HT3 receptor antagonists tropisetron (0.5 mg/kg i.p.) and DAU 6215 (60 micrograms/kg i.p.), but not by the mixed 5-HT1 and 5-HT2 receptor antagonist metergoline (2 mg/kg s.c.). In accordance with an involvement of the 5-HT3 receptor in the ACh facilitation induced by d-norfenfluramine is the finding that the selective 5-HT3 receptor agonist 2-methylserotonin (250 micrograms i.c.v., or 10 microM applied by reverse dialysis) raised ACh release. The effect of the intracerebroventricular drug was prevented by the 5-HT3 antagonists DAU 6215 (60 micrograms/kg i.p.) and ondansetron (60 micrograms/kg s.c.). These antagonists by themselves did not modify the basal ACh release, indicating that 5-HT does not tonically activate the 5-HT3 receptors involved. In conclusion, the overall regulatory control exerted by 5-HT in vivo is to facilitate hippocampal ACh release. This is mediated by 5-HT3 receptors probably located in the dorsal hippocampi.

Acetylcholine↗
PubMed1993

Differences between rat dorsal and ventral hippocampus in muscarinic receptor agonist binding and interaction with phospholipase C.

Carbachol, a full muscarinic receptor agonist, stimulated [3H]inositol phosphate accumulation in both the ventral and dorsal hippocampus, but its efficacy and affinity were higher in the former area. The partial agonist oxotremorine had a weak stimulatory effect in both regions. The affinity profiles of pirenzepine and AF-DX 116 in antagonizing carbachol-stimulated [3H]inositol phosphate accumulation indicated that M1 and M3 receptors contributed equally to the response in either region. On the other hand, there were no differences in the receptor density, or in the distribution of muscarinic receptor subtypes between the two regions of the hippocampus which could account for the effect as determined in binding experiments with selective antagonists. Analysis of carbachol binding curves did, instead, indicate a difference in the way the agonist interacted with the receptors within the hippocampus, i.e., carbachol recognized three agonist affinity states (superhigh, high and low) in the ventral hippocampus, and only two (high and low) in the dorsal part. The findings thus suggested that the regional diversity in the efficacy of carbachol in stimulating phosphoinositide turnover was related to the complexity with which it bound to muscarinic receptors. Transduction processes that intervene between changes in the muscarinic receptors' conformation and activation of phospholipase C might be relevant to these differences.

Alkaloids↗
PubMed1992

Dopamine depletion preferentially impairs D1- over D2-receptor regulation of striatal in vivo acetylcholine release.

The roles of D2 and D1 dopaminergic receptors on the regulation of striatal acetylcholine (ACh) release in vivo were examined for a period of 120 min after acute (2 h) or prolonged (16 h) depletion of brain dopamine (DA) by alpha-methyl-p-tyrosine. The reduction of DA transmission did not affect basal ACh output after 2 h but markedly lowered ACh release by 16 h (50%). Acute alpha-methyl-p-tyrosine pretreatment prevented the reduction of ACh release by the D1 antagonist SCH 23390 and its increase by the D2 antagonist, remoxipride, consistent with a drastic reduction of DA transmission at both DA receptors. However, 16 h after alpha-methyl-p-tyrosine, the effect of remoxipride on ACh release was restored, but SCH 23390 still had no effect, suggesting that the D2 inhibitory tone on ACh release had recovered, whereas the reduction of the D1 facilitatory influence persisted. The D1 facilitatory control of ACh neurotransmission thus appears to be more sensitive than the D2 inhibitory control to a reduction in DA transmission. The new model of DA-ACh interaction resulting from these data casts fresh light on the relationship between changes in DA transmission and extrapyramidal motor function.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMed1991

Pertussis toxin-sensitive G-protein mediates galanin's inhibition of scopolamine-evoked acetylcholine release in vivo and carbachol-stimulated phosphoinositide turnover in rat ventral hippocampus.

The effects of intracerebroventricular (i.c.v.) injections of pertussis toxin were investigated on the inhibitory action of galanin on acetylcholine release and phosphoinositide breakdown stimulated by muscarinic agents in rat ventral hippocampus. Pertussis toxin (0.6 micrograms, i.c.v., 96 h) counteracted the in vitro inhibitory effect of galanin (3.1 nmol) on phosphoinositide breakdown stimulated by carbachol without altering the stimulatory action of the cholinergic agonist on signal transduction, in miniprisms from rat ventral hippocampus. Pertussis toxin also abolished the in vivo effect of galanin on scopolamine-stimulated acetylcholine release in vivo but did not affect basal acetylcholine release. The results indicate that pertussis toxin-sensitive G-protein(s) mediates the galanin receptor regulation of pre- and postsynaptic cholinergic functions in the ventral hippocampus.

Acetylcholine↗
PubMed1991

Galanin reduces carbachol stimulation of phosphoinositide turnover in rat ventral hippocampus by lowering Ca2+ influx through voltage-sensitive Ca2+ channels.

The 29-amino-acid peptide galanin (GAL) caused concentration-dependent inhibition of the accumulation of 3H-inositol phosphates (3H-InsPs) induced by the muscarinic agonist carbachol (CARB; 10(-3)-10(-5) M) in the presence of 5 mM lithium, specifically in tissue miniprisms from rat ventral hippocampus. The inhibitory effect of GAL involved the mono-, bis-, tris-, and tetrakisphosphates formed during activation for 2 min of phospholipase C by CARB (1 mM) in the absence of lithium. GAL (1 microM) did not affect alpha-adrenergic or serotonergic type 2 receptor-mediated phosphoinositide (PI) breakdown in the same tissue. GAL by itself neither acted on basal levels of 3H-InsPs nor affected muscarinic receptors in binding studies. Blockade of the T-, N-, and L-types of voltage-sensitive calcium channel (VSCC) with 200 microM Cd2+ reduced muscarinic receptor-mediated PI breakdown by 50% and abolished the inhibitory effect of GAL (1 microM). Reduction of the extracellular Ca2+ concentration from 1.3 mM to 0.49 microM abolished the GAL inhibition of CARB-stimulated PI hydrolysis. Ca2+ influx promoted by 18 mM K+ depolarization or by 1 microM Bay K 8644, a selective agonist of the L-type VSCC, prevented the inhibitory effect of GAL. Blockade of the L-type VSCC with nifedipine (1 microM) potentiated the inhibitory effects of GAL without affecting muscarinic stimulation of PI breakdown.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗