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Biomedical subjects

U Tannuri

Publications and source records attributed to U Tannuri.

At least 19 recordsLinked to original sources
PubMed2004

Pediatric liver transplantation: fourteen years of experience at the children institute in São Paulo, Brazil.

This study reports the 14-year experience of a single center on 206 liver transplantations from living and cadaveric donors performed in 179 pediatric patients. Biliary atresia (57.2%) and fulminant hepatitis (9.8%) were the most frequent indications. The mean age of the recipients was 3 years, 7 months (9 months to 18 years) and mean weight was 14 kg (7 to 57 kg). The allografts were distributed as 82 (39.8%) whole cadaveric, 76 (36.9%) reduced-size cadaveric, 46 (22.3%) living donor liver transplants, and 2 (0.9%) ex situ split livers. The waiting periods were 25 days for living donors and 2.5 years for cadaveric donors (P <.001). Twenty-seven children were retransplanted with hepatic artery thrombosis the most frequent indication. The postoperative complications were: primary nonfunction (12.2%), biliary stenosis (28.8%), hepatic artery thrombosis (12.2%), portal vein stenosis (4.9%), hepatic vein stenosis (6.9%), and lymphoproliferative disorder (5.9%). The diagnosis of biliary stenosis was obtained by liver biopsy and transhepatic cholangiography and treated by balloon dilatation, although four children (3.9%) required a redo hepaticojejunostomy. The venous stenoses were percutaneously dilated with five-children (4.9%) requiring venous stents. The incidence of hepatic vein stenosis was 15.6% among living donor and 2.5% in cadaveric liver transplantation (P <.05). The overall 5-year patient and graft survivals were 70.2% and 65.1%. Liver transplantation provides excellent long-term survival. The use of grafts from living donors decreases the waiting periods but increases the incidence of hepatic vein stenosis.

Brazil↗
PubMed2004

Basiliximab-chimeric anti-IL2-R monoclonal antibody in pediatric liver transplantation: comparative study.

Basiliximab is a monoclonal antibody that binds to the alpha subunit (CD(25)) of the interleukin-2 receptor of activated T lymphocytes. The advantage of basiliximab in organ transplantation is the reduce possibility to calcineurin inhibitor dosages to avoid nephrotoxicity. Basiliximab has significantly reduced the incidence of acute rejection (AR) in renal transplant recipients; however, the results are uncertain in liver transplantation (LT). The objective of this investigation was to assess the effect of basiliximab to prevent AR in the first 6 months after pediatric LT. From March 2000 to October 2001, 32 recipients of a primary orthotopic cadaveric or living donor LT were given basiliximab by intravenous bolus injection on the day of transplantation (day 0) and on day 4. Four children who received one dose were excluded from the study. The rate and the intensity of AR episodes, the incidence of chronic rejection, serum creatinine level, incidence of infections, adverse side effects, and daily oral dosage of cyclosporine (Neoral) to maintain the target blood level of 850 to 1000 mg/dL at C2, 2 hours after the administration, were analyzed in the remaining 28 recipients. Results were compared to those obtained from a matched historical group (n = 28) of similar age, weight, and hepatic diseases distribution. None of the analyzed parameters was statistically significant (P >.05) except for the daily oral dose of cyclosporine (7 to 13 mg/kg/dose, P <.05). In our series, the addition of basiliximab to the immunosuppressive therapy did not reduce the incidence of AR in pediatric LT.

Adolescent↗
PubMed2003

Livaditis' circular myotomy does not decrease anastomotic leak rates and induces deleterious changes in anastomotic healing.

Considering that Livaditis' myotomy is still accepted as a good method for lengthening the esophagus to allow primary repair of long-gap esophageal atresia, the aim of this experimental study was to verify if this procedure decreases the incidence of leaks in anastomoses performed under severe tension. In addition, it was verified whether the myotomy promotes any morphological or biochemical change in the healing esophageal anastomosis. Sixty small dogs were submitted to a cervicotomy and resection of an esophageal segment (8.0 - 10.0 cm) resulting in an anastomosis under severe tension. The animals were divided into two groups (control group: only anastomosis; experimental group: anastomosis plus circular myotomy in the proximal esophageal segment). The animals were sacrificed on the 14th postoperative day, submitted to autopsy, and were evaluated as to the presence of leaks. Twelve scars of each group were collected for histological, histomorphometric (evaluation of scar thickness), electrophoretic and immunoblotting studies of collagen (total collagen and types of collagen determinations). Leak rates were the same in both groups. Histologic examination showed that the scar at the anastomosis was formed by fibrous tissue, without mucosa or muscular tissue. In the myotomy animals, a decreased number of newly formed small vessels was noted in comparison to control animals, and morphometric analysis showed that in the myotomy animals the anastomotic scar was thinner than in the control animals. Biochemical analysis of scars demonstrated that myotomy promoted a decrease in the soluble collagen content in comparison with the control animals and no alteration in the content of insoluble collagen. The electrophoretic separation of the types of collagen and characterization by immunoblotting demonstrated the presence of collagen types I, III, and V, and the quantification by densitometry of the bands showed a reduction in collagen type V (present in the blood vessels) in the myotomy animals in comparison to controls. This result is in accordance with the histological observation of a decrease in newly formed blood vessels. Circular myotomy does not decrease the possibility of anastomotic leaks, in addition to promoting deleterious changes in anastomotic healing.

Anastomosis, Surgical↗
PubMed1999

The effects of early and delayed immunosuppression in experimental tracheal transplantation with omentopexy.

BACKGROUND/PURPOSE: Best results in experimental tracheal allotransplantation are obtained when metachronous revascularization by omentopexy and immunosuppression are used. Nevertheless, this method of revascularization implies in a 4-day period of ischemia to the graft. The aim of this study was to assess the influence of the 4-day period of ischemia on host sensitization as well as the effect of early or delayed immunosuppression on the outcome of the grafts. METHODS: Thirty rabbits were submitted to tracheal allotransplantation and divided according to position of the graft (orthotopic or heterotopic transplants) and the initiation of immunosuppression (early or delayed). The quality of the revascularization was evaluated by the identification of Indian ink, perfused through the abdominal aorta, inside the submucosal vessels. The outcome of the grafts was evaluated by histological analysis according to a semiquantitative scale of alterations. RESULTS: Grafts were better revascularized in heterotopic position. Grafts with late immunosuppression presented good outcome only when heterotopically positioned. No significant differences were observed in grafts placed heterotopically or orthotopically when immunosuppression was initiated early after the transplant. CONCLUSIONS: Transient ischemia produced by metachronous revascularization is not the single factor responsible for the histological alterations observed in tracheal allografts. These alterations probably also are produced by the activation of immune responses. This activation is more intense in more ischemic grafts, but can be suppressed by early administration of immunosuppression.

Animals↗
PubMed1998

The effects of prenatal intraamniotic surfactant or dexamethasone administration on lung development are comparable to changes induced by tracheal ligation in an animal model of congenital diaphragmatic hernia.

BACKGROUND/PURPOSE: Lung surfactant deficiency contributes to the pathophysiology of congenital diaphragmatic hernia (CDH) and the high neonatal mortality rate. Acceleration of lung surfactant system maturation by prenatal administration of hormones has been described in animal models of CDH. However, in utero tracheal ligation (TL) is the best method to accelerate lung growth and reverse the pulmonary hypoplasia associated with CDH. Although this method offers promise, its application in humans is limited. The aim of this study was to investigate a new noninvasive therapeutic strategy, that is, the prenatal intraamniotic administration of exogenous porcine surfactant or dexamethasone, and compare it with the effects of TL in an animal model of CDH. METHODS: Twenty-four pregnant New Zealand rabbits underwent surgery on gestational day 24 or 25 to create CDH in 26 fetuses. Five groups of animals were studied: (1) Control, nonoperated fetuses (n=14), (2) CDH (n=6), (3) CDH plus TL (n 6), (4) CDH plus intraamniotic administration of Curosurf (40 mg; n=6), and (5) CDH plus intraamniotic infusion of dexamethasone (0.4 mg; n=8). On gestational day 30, the fetuses were delivered by cesarean section. Functional studies (lung hysteresis curves and lung distensibility), weight and volume of lungs, histopathologic and histomorphometric analysis of lungs were performed. RESULTS: The authors demonstrated that the hysteresis curve of CDH animals was shifted downward in comparison with controls. The analyses of curves standardized for lung weight indicated that intraamniotic administration of surfactant or dexamethasone improved lung compliance in comparison with controls and CDH fetuses, but TL had no effect on this parameter. Lung distensibility (maximum lung volume at 32 cm of water pressure per gram of lung) was reduced by CDH, but this parameter was increased by intraamniotic administration of drugs and not by TL (P< .05). CDH decreased the weight and volume of lungs (P< .05), and these changes were reversed only by TL, which prevented the herniation of the liver from the abdomen to the thorax. Histologically, CDH lungs treated with TL or intraamniotic administration of drugs demonstrated structural patterns similar to those of controls. Histomorphometric studies proved that CDH promoted significant thickening of septa walls (P< .05), and all the therapeutic methods could reverse this alteration to control values. The alveolar number per area in control lungs, CDH, and CDH plus TL lungs were similar, but in CDH plus surfactant and CDH plus dexamethasone lungs, the decreased number per area (P< .05) demonstrated that the alveolar airspace was increased. CONCLUSION: From these data the authors conclude that intraamniotic surfactant or dexamethasone administration is capable of preventing pulmonary hypoplasia in fetuses with CDH, and thus, this method may be a substitute for TL.

Analysis of Variance↗
PubMed1998

The effects of prenatal intraamniotic surfactant or dexamethasone administration on lung development are comparable to changes induced by tracheal ligation in an animal model of congenital diaphragmatic hernia: studies of lung glycogen content, elastic fiber density, and collagen content.

BACKGROUND/PURPOSE: A new noninvasive therapeutic strategy, which consisted of prenatal intraamniotic administration of porcine surfactant or dexamethasone, was previously used to prevent the functional and structural immaturity of lungs associated with congenital diaphragmatic hernia (CDH), and its effects on lung development were comparable with the changes induced by tracheal ligation (TL). The purpose of this study is to verify if this novel therapeutic modality has any effect in the elevated concentration of lung glycogen and altered contents of lung elastic fiber and collagen promoted by CDH. METHODS: A pilot study was performed to investigate in the rabbit model if the infused drugs in the amniotic cavity were aspirated by the CDH and non-CDH fetuses, and if there was correspondence between lung immaturity and high glycogen concentration in lung tissue. Experimental groups consisted of 50 pregnant rabbits that underwent surgery on gestational day 24 or 25 to create left-sided diaphragmatic hernias in 56 fetuses, which were divided in groups according to the procedures: CDH (n = 12), CDH plus TL (n = 16), CDH plus intraamniotic administration of Curosurf (40 mg, n = 12), and CDH plus intraamniotic administration of dexamethasone (n = 16). On gestational day 30, the fetuses were delivered by cesarean section, and 28 normal unoperated fetuses served as controls. The lungs were weighed and submitted to biochemical determination of glycogen, morphometric evaluation of elastic fibers, and colorimetric analysis of collagen. RESULTS: In all CDH and non-CDH fetuses of the pilot study, the amniotic content was massively aspirated into the lungs and trachea. There was an increase in lung glycogen content of fetuses at 24 days' gestation in comparison with 20-day gestational age fetuses, followed by a decrease in the near full-term fetuses. In the fetuses of the experimental groups, CDH decreased the lung weight to body weight ratios of lungs ipsilateral to the hernia. These changes were reversed by TL but not by intraamniotic administration of surfactant or dexamethasone. Lung glycogen concentrations in the lungs of CDH fetuses were significantly higher than those in the control group. These changes were reversed by intraamniotic administration of surfactant but not by dexamethasone administration or TL. In the lungs ipsilateral to the hernia, surfactant administration promoted a significant decrease in glycogen content to levels lower than control lungs. CDH promoted a decrease in the linear density of elastic fibers in both lungs, ipsilateral and contralateral to the hernia. This alteration was partially corrected by TL and surfactant administration, although dexamethasone administration had no effect. The concentrations of collagen in both lungs were increased significantly by CDH, and these alterations could not be reversed by TL. In the lungs ipsilateral to the hernia, intraamniotic administration of surfactant or dexamethasone promoted a significant decrease in the lung concentration of collagen but not to control levels. CONCLUSIONS: The positive effects of intraamniotic surfactant or dexamethasone administration on lung maturity of fetuses with CDH were observed. This therapy may be a substitute for TL.

Animals↗
PubMed1994

Surgically produced congenital diaphragmatic hernia in fetal rabbits.

Animal models of congenital diaphragmatic hernia (CDH) still are indispensable for the evolution of knowledge related to this disease and to fetal surgery in general. The lamb has provided the most reliable experimental design thus far. Considering the possible advantages of using rabbits (rather than lambs) namely lower costs, no need of special veterinary facilities, smaller body size, year-round availability, higher number of fetuses per pregnancy, and shorter gestational period, a successful model of CDH was developed in fetal rabbits. Sixteen pregnant New Zealand rabbits underwent hysterotomy and fetal operation. Group 1 (6 does) underwent surgery on gestational day 20 and group 2 (10 does) on gestational day 24 or 25. The normal full gestation time is 31 to 33 days. In group 1, the CDH was created by transabdominal puncture and dilatation of the fetal diaphragm. In group 2, the CDH was created through open thoracotomy, either left or right. The fetuses were delivered by cesarean section on gestational day 30. The overall fetal survival rate was 0 for group 1 and 70% for group 2. All operated fetuses in group 2 that were born alive had CDH. The histological morphometric examinations (radial alveolar count after sustained lung expansion) of the normal and operated fetuses in group 2 showed pulmonary hypoplasia in all the lungs on the same side as the CDH (statistical analysis was performed using the Neuman-Keuls test and analysis of variance; the significance level was set at .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Esophagocoloplasty in children: surgical technique, with emphasis on the double blood supply to the interposed colon, and results.

The description of certain surgical technical modifications of pediatric esophagocoloplasty and their impact on morbidity and mortality rates are presented. Seventy children, aged 12 to 120 months (mean, 52.3 +/- 39.5), were divided in two groups. Group 1 (40 patients), which represents a historical group, underwent esophagocoloplasty by the conventional technique. Group 2 (30 patients) had the following modifications to the operation: (1) preservation of the double blood supply to the interposed colon, based on the left colic vessels and left paracolic arcade, via the sigmoid vessels; (2) low cologastric anastomosis, performed at the lowest level of the anterior antrum; (3) in cases of retrosternal transposition (25 patients), fixation of the inferior border of the liver to the diaphragm and anterior abdominal wall; and (4) complete section of the left anterior muscles, behind the colon. Five patients in group 2 were supposed to undergo surgical correction of a congenital cardiac anomaly and had the colon transposed through the posterior mediastinum, on the original esophageal bed. The incidence of graft necrosis, gastrocolic reflux, esophagocolic anastomotic leak, and dysphagia are compared between the groups; the survival rates also were compared. Statistical analysis was performed using the Fisher-Yates' test, with significance set at .05. Groups 1 and 2 had the following complication rates, respectively: graft necrosis, 12.5% and 0% (P < .05); gastrocolic reflux, 20.0% and 0% (P < .05); dysphagia, 9.5% and 0% (P < .05); and esophagocolic anastomosis leak, 28.5% and 33.3% (not significant). The mortality rate was 17.5% for group 1 and 3.5% for group 2 (P < .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Anastomosis, Surgical↗
PubMed1991

Total gastric transposition: an alternative to esophageal replacement in children.

Total gastric transposition was performed in 21 children as an alternative procedure for esophageal replacement. The age at the operation ranged from 15 months to 11 years. Half of the children were less than 2 years old. Fifteen patients had esophageal atresia. The stomach was passed toward the neck either through the esophageal bed (6 cases, with concomitant blunt esophagectomy without thoracotomy) or the retrosternal route (15 cases). There was one death in the early postoperative period secondary to an anastomotic leak and acute mediastinitis in a case of pharyngogastric anastomosis. Three other patients developed cervical leak with spontaneous closure but this ultimately led to a late anastomotic stricture (more than 6 months) requiring endoscopic dilatation. Only one child needed more than three attempts of endoscopic dilatation. None of these patients required surgical revision. The mean follow-up was 60 months (range, 10 to 122 months). Despite bulky atonic intrathoracic stomach occurring in some children, only two patients developed regurgitation and symptoms of poor gastric emptying. There were neither early nor late respiratory problems. Excellent and good functional outcome were achieved in 85% and 15% of the patients, respectively. Two patients have not undergone a weight catch-up phase. The majority of the children have been between the 20th and 80th percentile for weight. Five children remain below the 20th and two below the 5th percentile. The remarkably low morbidity and mortality combined with satisfactory functional results indicate that the total gastric transposition is a safe and easy alternative surgical procedure for esophageal replacement in children.

Child↗
PubMed1987

Must fat emulsions and parenteral nutrition solutions be given through separate circuits?

To test the stability of fat emulsions with parenteral nutrition (PN) solutions, 10% soybean fat emulsion (FE) was suspended in PN solutions containing amino acids, electrolytes, vitamins, and different glucose concentrations. Six different mixtures were prepared and analyzed after 15 minutes or 24 hours, under transmission electron microscope: 10% fat emulsion (FE); FE + PN solution with 5% glucose (15 minutes); FE + PN solution with 5% glucose (24 hours); FE + PN with 12.5% glucose (24 hours); FE + PN with 25% glucose (24 hours); and FE + pure glucose 50% (24 hours). The addition of FE to PN solutions containing 5% to 25% glucose did not cause coalescence, aggregation, or confluence of the liposomes or damage to their surface in the first 24 hours after admixture. However, the suspension of fat emulsion in a 50% glucose solution coalesced liposomes and the droplets were nearly all aggregated. We conclude that mixtures of FE with PN solutions with glucose are stable for at least 24 hours and are suitable for clinical use.

Drug Stability↗
PubMed1982

Effect of insulin on protein catabolism after injury in young animals.

Injury is followed by a negative nitrogen balance, muscle protein breakdown and loss of body mass. The intensity of these changes correlates with trauma severity. Reversion of the catabolic state has long been attempted. Recently, it has been shown that the use of insulin might inhibit protein catabolism after severe trauma. The present study was undertaken to assess the effect of insulin on post-injury catabolism in young rabbits submitted to parenteral nutrition. Concomitantly, changes in liver and skeletal muscle nitrogen contents were also studied to elucidate the mechanism of insulin's anabolic effect after trauma. We found that only in catabolic states did insulin produce a significant nitrogen-sparing effect, probably due to the capacity of the hormone to inhibit muscle proteolysis.

Animals↗