PubMed Health⌕ Search

Biomedical subjects

J A Tovar

Publications and source records attributed to J A Tovar.

At least 19 recordsLinked to original sources
PubMed2007

Expression of homeotic genes Hoxa3, Hoxb3, Hoxd3 and Hoxc4 is decreased in the lungs but not in the hearts of adriamycin-exposed mice.

Exposure of rat and mouse embryos to adriamycin (doxorubicin chlorhydrate) induces esophageal atresia (EA) and VACTERL association. Sonic hedgehog (Shh) and Gli2/Gli3 pathways are involved in these conditions and knockout mice for homeotic Hox genes Hoxa3, Hoxb3, Hoxc3, Hoxc4 and Hoxa5 show phenotypes with some of the associated VACTERL features. This study aims at evaluating the possible influence of Hoxa3, Hoxb3, Hoxd3 and Hoxc4 as upstream regulators of this complex signalling. Pregnant mice were exposed either to 4 mg/kg of adriamycin (EA group) or vehicle (controls) on embryonic days 7.5 and 8.5. Embryos were recovered at four endpoints (E12.5-E15.5) and randomly assigned for immunohistochemical or molecular biology studies. Lungs and hearts were separately harvested and processed for Hoxa3, Hoxb3, Hoxd3 and Hoxc4 quantitative RT-PCR measurements. Antibodies for Hoxa3, Hoxb3 and Hoxd3 proteins were used for immunohistochemical studies. RT-PCR studies showed a drastic and statistically significant decrease of the four genes in the lungs of EA mice when compared to controls, with a slight recovery from E15.5. Hearts of both groups showed a similar expression of all the genes throughout gestation. Control embryos expressed the hox3 paralogous genes in heart, skin, foregut derivatives and their surrounding mesoderm through E12.5-E15.5 whereas adriamycin-exposed embryos showed a severe decrease in expression of these three proteins in the same tissues but not in the heart. Adriamycin drastically reduced the expression of Hoxa3, Hoxb3, Hoxd3 and Hoxc4 in mice embryonic lungs. Their expression in the heart did not seem to be influenced by adriamycin in this experimental setting.

Animals↗
PubMed2006

Organ changes and bacterial translocation in a rat model of chronic rejection after small bowel transplantation.

UNLABELLED: Rejection after small bowel transplantation (SBTx) may allow bacterial translocation damaging the liver and lungs. This study investigated these issues in a rat model of chronic rejection. MATERIALS AND METHODS: Orthotopic SBTx was performed in syngeneic (SYN) (ACI-ACI, n=8) and allogeneic (ALLO) (ACI-Lewis, n=8) rat strain combinations. Cyclosporine was given to ALLO rats for 28 days. Animals were sacrified between 55 and 65 days. Lymph nodes and venous samples were cultured; Escherichia coli DNA was assessed by polymerase chain reaction. We measured intestine, liver, spleen, and lung protein and DNA contents. Chronic rejection was histologically confirmed. RESULTS: Two of eight and four of eight rats died in the first week after SYN and ALLO SBTx, respectively. There were no differences in organ weights or DNA and protein contents compared with the controls. Gram-negative enteric bacteria were found in two of four ALLO and two of six SYN rats (ns), and aerobic gram-positive were found in two of four and two of six (ns), respectively. Anaerobic growth occurred in mesenteric lymph nodes in only one ALLO rat. E. coli DNA was negative in all animals. Lungs were severely emphysematous in ALLO rats with no histologic changes observed in the other phagocytic organs. Mild rejection was found in the intestine of ALLO rats. CONCLUSIONS: Bowel lesions in ALLO rats might be consistent with chronic rejection and lung lesions could be related to bacterial translocation after SBTx. However, contrary to our expectations, no significant bacterial translocation was demonstrated in either group at the end of the experiments.

Animals↗
PubMed2006

Liver transplantation for malignant tumours in children.

OBJECTIVE: The object of this study was to analyse our results with liver transplantation (LTX) for primitive malignant unresectable liver tumours in children and to discuss the controversial indications, based on our experience. METHODS/PATIENTS: We report on 12 patients, aged 6 months to 14 years, with hepatic malignant tumours: 11 with hepatoblastoma and 1 with fibrolamellar hepatocelullar carcinoma without cirrhosis. LTX was the primary treatment in 10 patients (PRETEXT IV or any grade, if there was extension to the retrohepatic vena cava, 3 hepatic veins or portal vein) and a rescue therapy after recurrence for 1 and for persistence of unresectable macroscopic residuals in 2 patients. One of the patients who underwent a LTX as primary therapy had lung metastases previously resolved with chemotherapy. We used entire liver (n = 5), left lateral segment from cadaveric donor (n = 3), living related donor (n = 3; 2 segments II-III and 1 right lobe) and left lateral segment from split liver (n = 1). All children received chemotherapy prior and post transplantation following the SIOPEL protocol. We analysed procedure tolerance, survival, recurrence rate, disease-free period and risk factors for adverse evolution. RESULTS: All patients overcame LTX and no early graft loss was recorded. Two cases died because of tumour relapse, 1 after primary LTX and 1 after rescue LTX (survival rate of both groups, 90% and 50%). Graft and patient survival rates at 1 year, 3 years, 5 years and 14 years were 91%, 91%, 82% and 82% respectively. The boy who presented with lung metastases developed new ones one year after LTX that were removed and he is currently free of disease. The disease-free period has a probability at 1, 3 and 5 years of 91%, 75% and 75%, respectively. Tumour tissue persistence was the only risk factor for an adverse clinical course in our series. CONCLUSIONS: LTX is a reasonable therapeutic approach for unresectable malignant liver tumours, providing outcomes comparable to those for resectable tumours. Results obtained with LTX are better when it is used as a primary treatment than when used as a rescue procedure. Proper staging and early referral to centres with enough expertise optimise the results. LTX for patients with lung metastases could be a controversial option. Living related-donor transplantation is an excellent alternative to avoid disease progression while on the waiting list for cadaveric donors.

Adolescent↗
PubMed2006

Nutritional status after intestinal transplantation in children.

INTRODUCTION: The management of children receiving small bowel grafts involves potentially life-threatening complications that affect their nutritional status. The aim of this paper was to define these factors and their influence on nutritional outcome. PATIENTS AND METHODS: Patients with intestinal failure (IF) who received an isolated small bowel transplantation (SBT) or small bowel/liver transplantation (SBLT) at our hospital during the last 6 years were reviewed for weight Z-score, biochemical nutritional parameters, total parenteral nutrition (TPN) weaning, catheter-related sepsis, rejection and steroid treatment. RESULTS: Twenty patients, 11 females and 9 males, received a SBT or a SBLT and survived the postoperative period; in the present study we only included 11 children with follow-up periods longer than 1 year. Seven males and 4 females with a mean age of 4.5 years (range, 1 to 20 years) received 6 SBLT and 5 SBT. Nine (82%) were weaned from TPN to an amino-acid or peptide enteral formula during the first 6 months after surgery. During the first year there was a significant increase in total protein from 5.11 +/- 1.8 mg/dl to 6.1 +/- 1.5 mg/dl (p < 0.05) and an increase in albumin from 3.8 +/- 0.9 mg/dl to 4.5 +/- 1.1 mg/dl (p < 0.05). There was an increase in weight Z-score in 9 patients (82%) during the first year. Mean Z-score improved from - 2.6 +/- 1 at transplant to - 1.0 +/- 0.6 (p < 0.05) after 1 year. Three patients (27.2%) had at least one rejection period, which was treated with steroids alone or in combination. Mean weight Z-score 1 year after surgery was - 0.9 +/- 0.6 for patients without rejection and - 1.24 +/- 0.8 for those with at least one rejection episode treated with steroids (p > 0.1). Four patients (36%) had at least one catheter-related sepsis episode. Mean weight Z-score 1 year after surgery was - 1.01 +/- 0.6 for patients without catheter-related sepsis and - 1.24 +/- 0.8 for those with at least one catheter-related sepsis episode (p > 0.1). CONCLUSIONS: There was a significant improvement in weight Z-score and biochemical nutritional parameters 1 year after receiving a small bowel graft. No influence of steroids or catheter-related sepsis on children's nutritional status was noted 1 year after surgery, although this point will need further evaluation.

Adolescent↗
PubMed2006

Non stenotic food impaction due to eosinophilic esophagitis: a potential surgical emergency.

AIM: Eosinophilic esophagitis (EoE) is an emergent condition in which a mucosal infiltrate of > 20 eosinophils per high power microscopic field is accompanied by motor disturbances that may cause food impaction in the absence of esophageal stricture. We report a series of such cases to point out the potential involvement of pediatric surgeons in diagnosis and treatment. Furthermore, data on the motor function of the esophagus investigated manometrically is included. MATERIAL AND METHODS: Thirteen patients with EoE were referred to our emergency room for acute food bolus impaction. Their median age at diagnosis was 12 years (range 7.6-14.4). History of allergy, endoscopy with biopsy and esophageal function (24-h combined ambulatory manometry with simultaneous pH-metry) were investigated. RESULTS: In 7 patients emergency endoscopic extraction of the impacted bolus was necessary. Allergic tests were positive in eight patients. The pH probe showed gastroesophageal reflux in two cases. Upon endoscopy, typical features of EoE (esophageal trachealization and whitish papular exudates) were found. Ambulatory 24-h manometry revealed abnormal motility of the distal esophagus with strikingly high amplitudes (> 150 mmHg) and long duration (> 7 sec) of the waves, particularly during the night. Six patients responded rapidly to steroids and/or antiallergic treatment. The remaining patients had a good outcome with dietary treatment alone. CONCLUSIONS: EoE is an emergent condition that may involve the pediatric surgeon in both the diagnosis and treatment. Typical endoscopic findings and biopsy are required for proper diagnosis. Ambulatory manometry reveals a marked propulsive dysfunction that explains impaction. This dysfunction is reversible, since the symptoms usually disappear with steroids or antiallergic treatment.

Adolescent↗
PubMed2006

[Bronchial and appendiceal carcinoid tumors].

BACKGROUND: Carcinoid tumor (CT) is an unusual neoplasm observed in several locations and associated with the production of vasoactive substances and occasionally with carcinoid syndrome (flushing, diarrhea, wheezing). PATIENTS AND METHODS: A retrospective review of the medial records of all children with a diagnosis of CT treated in our service between 1966 and 2003 was performed. RESULTS: Ten patients (5 boys and 5 girls with a mean age of 8 years) were diagnosed with CT. Eight had CT of the appendix, of which 4 showed the typical clinical presentation of acute appendicitis. Seven of these tumors were localized at the tip of the appendix and measured 2 cm or less. In one patient, the tumor was located at the cecum and measured 3.5 cm. In this patient, reoperation with ileocecal resection was performed. Two patients (4 and 6 years old) had bronchial CT associated with chronic respiratory manifestations. An accurate diagnosis was made after a 1-year follow-up. Pneumonectomy and tracheobronchial sleeve resection were carried out. None of the patients showed symptoms of carcinoid syndrome. All the patients underwent biochemical and radiological studies and fiberoptic bronchoscopy during follow-up. All the patients are currently disease-free. CONCLUSIONS: Typical symptoms of acute appendicitis were not observed in half of patients with CT of the appendix. CT associated with carcinoid syndrome is exceptional in pediatric patients. In most CT of the appendix, simple appendicectomy was associated with an excellent prognosis. Diagnosis of bronchial TC tends to be delayed and consequently CT should be considered in the differential diagnosis of children with respiratory symptoms unresponsive to standard medical treatment.

Appendiceal Neoplasms↗
PubMed2006

[Surgical management of cutaneous and musculoskeletal complications in fulminant sepsis].

INTRODUCTION: Surgical management of purpura fulminans is required as in the acute as in the sequelae period. A retrospective case review of these sequelae, procedures which have been performed in the different moments and the outcomes was undertaken. METHODS AND MATERIALS: We reviewed retrospectively 13 patients treated in our hospital from 1993 to 2003. 8 males and 5 females, with a median age of 2 years old (4 days-14 years) were managed. 70% were meningococcical. The most common areas were low extremities (92%), upper extremities (76%), lips (n=1), nose (n=1) and genitalia (n=1). Most of cases were bilateral (n=11) although two patients presented isolated affectation in one of the extremities. The procedures were classificated depending on the surgical moment. Clinical follow-up was attempted on all surgical patients; we evaluated the aesthetic, functional and psychosocial outcomes. RESULTS: One child died along the first 24 hours; 11 required early surgery and all of them required late interventions. 50% in the serie had necrosis over 15%. In Intensive Care Unit, it was necessary to do 6 fasciotomies (extirpating muscle in 2) and escharectomies and debridements in 8. Early amputations were made in 2 patients: both of them required ampliation in the following days. The cutaneous defects were covered with skin allografts and artificial dermis. During the sequelae period, 8 amputations were necessary (the four extremities in one case). Other procedures were coverage with autologous skin grafting (n=7), Zplasties, Wplasties (n=5), myocutaneous flaps (n=3), release of contractures (n=3) and osseus resection (n=5). There were skeletal growth disturbances which were managed with osteotomies (n=3), realineations(n=3), application of Ilizarov (n=2) and Hoffman (n=2) frames; Nowadays, 6 patients have a complete independent functionning with the use of orthotics (n=3) and prosthetics (n=3) CONCLUSION: The pediatric surgeon has an important role in management and prevention of complications in patients with purpura fuminans. Urgent actuation and close follow-up decreases the morbidity; furthermore, the early reparation of sequelae improves their adaptation in school, in the family and in the society despite the physical disability.

Acute Disease↗
PubMed2006

[Thyroid C cells are decreased in experimental CDH].

BACKGROUND/AIM: Experimental CDH is often associated with malformations of neural crest origin. Several of these features are present in human CDH and therefore likely similar pathogenic mechanisms should be explored. The aim of the present study is to examine whether thyroid C-cells, another neural crest derivative, are abnormal in this rat model. METHODS: Pregnant rats were exposed either to 100 mg of 2-4-dichlorophenyl-p-nitrophenyl ether (nitrofén) or vehicle (controls) on 9.5 day of gestation. Fetuses were recovered on day 21st and the thyroids of those with CDH (68%) were immuno-histochemically stained with anti-calcitonin antibody. The number of positively stained cells per high power field were counted using a computer-assisted image analysis method in at least 5 sections per thyroid. The distribution of the cells within the gland was assessed as well. Comparisons between CDH and control rats were made by non-parametric tests with a significance threshold of p<0.05. RESULTS: The number of c-cells was dramatically reduced in CDH animals in comparison with controls (101.2 +/- 61.3 vs 23.1 +/- 37, p<0.0001). Histology of the thyroid was similar in both groups, but the distribution of positive C-cells within the gland followed an abnormal pattern in CDH rats with the cells tending to be located at the periphery rather than at the core of the lobes. CONCLUSIONS: Nitrofén induces a severe decrease in thyroid C cells accompanied by abnormal distribution patterns. These results add further evidence of the involvement of a neural crest dysregulation as a component of the pathogenesis of experimental CDH. Whether there is or not a clinical counterpart to these findings is still unknown, but the nature of the cardiovascular and craneo-facial malformations in some babies with CDH strongly support further research in this field.

Animals↗
PubMed2005

European multicenter survey on the laparoscopic treatment of gastroesophageal reflux in patients aged less than 12 months with supraesophageal symptoms.

BACKGROUND: This multicenter survey includes neonates and infants who underwent surgery for primary gastroesophageal reflux (GER) who presented with supraesophageal symptoms of unknown origin with a minimum of 12 months postoperative follow-up. METHODS: A total of 726 patients underwent GER surgery in 10 European Centers in the period 1998-2002. Respiratory symptoms were present in 204 patients (28%); 135 patients (17%) had surgery under 1 year of age, and 46 of them (6.3%) because of respiratory symptoms. Surgery was performed without any previous medical treatment in 10 cases (21%). The type of procedure included 37 complete 360 degrees wraps (80%) (Nissen, 12, and Rossetti, 25) and nine partial wraps (20%) (Thal five, Lortat Jacob one, Toupet one, others two). Gastrostomy was associated in 17 cases (37%) (6 PEG and 11 modified Stamm). No gastric emptying procedures were recorded. RESULTS: No major intraoperative complications were reported. Six patients developed complications (13%) and a redo operation was performed in three (6.5%). Respiratory outcome after antireflux surgery was good in 35 patients (76%) and fair with significantly improved respiratory symptoms in 11 (24%). CONCLUSIONS: This multicenter survey underlines that GER has to be suspected and aggressively treated in infants with difficult-to-treat supraesophageal symptoms, and also in high-risk cases, in order to prevent major complications.

Europe↗
PubMed2005

[Chest wall distraction in thoracogenic scoliosis].

INTRODUCTION: Combined congenital scoliosis and rib fusion associated with other chest deformities during infancy can lead to a progressive hypoplastic thorax that could be unable to support normal lung growth and respiratory function. Campbell introduced an expansion thoracoplasty technique in which fused ribs are separated and a vertical expandable prosthetic titanium rib is used as a chest wall distraction device to enlarge the affected hemithorax. This technique benefits the underlying lung by improving the thoracic volume and the respiratory function. PATIENTS AND METHODS: Four patients (3 boys and 1 girl) with severe unilateral thoracic deformity with combined scoliosis and rib fusion plus a restrictive respiratory insufficiency are presented herein; 1 of them needed continuous CPAP preoperatively. All had progressive scoliosis and failure to thrive. Preoperative evaluation included three-dimensional CT reconstruction. A thoracic expansion placing an intercostal vertical expandable prosthetic titanium device as a chest wall distractor was performed. Afterwards, distraction control was made every four months. RESULTS: Our 4 patients had a satisfactory outcome. Scoliosis was corrected and there were improvements of volume and function of the thorax. CONCLUSIONS: The placement of an intercostal distractor device improves the thoracic insufficiency syndrome, lengthening and expanding the thoracic cage at the same time. These effects benefit respiratory function and correct scoliosis, allowing an adecuate lung function.

Child↗
PubMed2005

[The impact of Glut-1 marker application on the diagnosis and treatment of congenital vascular anomalies].

Hemangiomas of infancy have a unique vascular phenotype demonstrated by glucose transporter 1 (GLUT-1) staining marker. Since its first description by P. E. North in 2000 its use has become widely spread by clinicians and researchers in the field of vascular anomalies. We prospectively and retrospectively used GLUT-1 marker on 90 patients divided in five groups over a two years period. Grupo I: Hemangiomas under 1 year of age. Grupo II: Hemangiomas between 1 and 15 years of age. Grupo III: Misdiagnosed angiomas in patients older than 15 years. Grupo IV: Patients with low and high flow vascular malformations Grupo V: Vascular tumors other than hemangiomas. As a result of the study, significant improvement has been noticed by the authors in appropiate vascular anomalies classification by primary care physicians involved in the study. Angioma is not anymore synonym of vascular birthmark. In addition the management of the newborn with a vascular tumour benefit from a more appropriate antiangiogenic therapy. Patients with RICH (rapidly involuting congenital hemangioma) or NICH (non involuting congenital hemangioma) pattern after biopsy and inmunohistochemical study did not receive any pharmacological agent as a part of their treatment. Finally GLUT-1 helped multidisciplinary vascular anomalies team development by promoting clinical, radiological and histopathologic correlations between different specialists.

Adolescent↗
PubMed2005

[Aplication of a 3D reconstruction model for the analysis of nitrofen induced intrathoracic malformations].

BACKGROUND: Three dimensional computer-assisted reconstruction offers some adventages for analysis and comparison of biological phenomena and anatomical structures. The CDH nitrofen-induced animal model associates multiple anomalies in neural-crest derived tissues. The goal of this study is to analyse by a 3-D reconstruction software the malformations in the extrinsic innervation of the esophagus in this model. METHODS: Nine control fetuses from 4 dams and 9 fetuses with CDH from 7 dams were studied. A thoracic block from the larynx to tracheal bifurcation was serially sectioned in the horizontal plane in every embryo. One in every 10 sections was stained with HE. The image was digitalized using biological software (TDR-3dbase). Vagus and recurrent laryngeal nerves, trachea, esophagus and the great vessels were examined. In order to obtain the 3-D reconstructions, 90 to 120 consecutive images were used. RESULTS: In comparison with controls there were striking abnormalities of these nerves in fetuses with CDH: 1) Absence of the left (2/9) or right (2/9) vagus nerves. 2) Absence of the left (3/9) or right (3/9) recurrent laryngeal nerves. 3) Marked hypoplasia of the trunk of the vagus (2/9). 4) Deviations of their normal course and change of normal anatomical relationships into the mediastinum (2/9). CONCLUSIONS: To fullfill our goals 3-D reconstructions allow a detailed analysis and provide a precise insight into the real anatomy. Rat fetuses with CDH have anomalies of the vagus and recurrent laryngeal nerves that support the concept of a neural crest involvement in the origin of this malformation. These observations may explain esophageal motility disorders in CDH.

Animals↗
PubMed2005

[Cardiac function alterations in pectus excavatum].

BACKGROUND: Cosmetic deformity and psychological repercusion are the main surgical indications in pectus excavatum. However cardiopulmonary function is subclinically abnormal in some patients. The goal of this paper is to demonstrate that heart response during physical activity improves after surgical correction of pectus excavatum. PATIENTS AND METHODS: Fifty five patients were operated upon for pectus excavatum during the last 10 years at our institution. Baseline ecocardiography and isometric effort test (Handgrip) were preoperatively performed in 15 patients (11 males and 4 females) aged from 6 to 15 years (median 9,63). An increase below 12% in cardiac index was considered as positive. In those patients with positive tests, a new test was made 6 months after surgical correction. Pre and postoperative results were compared using non-parametric tests. RESULTS: Baseline cardiac index values were normal in all cases (11). Four patients were not included, 2 because of no collaboration (aged 6 and 7 years) and 2 because difficult ecocardiography interpretation (both operated upon for congenital diaphragmatic hernia). Overall, preoperative test was negative in 6 patients and positive in the remaining 5. Postoperative test was made in these 5 patients, and all of them showed an improvement in cardiac index (medium 40,6%, range 25-70) when compared to preoperative values. There was statistically significant association between test values and patient ages. CONCLUSIONS: Baseline cardiac index values were normal in children with pectus excavatum, albeit 45,5% of them showed a limited response to exercise. Pectus excavatum repair improves these values, so physiopathological indication as well as cosmetic one should be considered specially in children.

Adolescent↗
PubMed2004

Bacterial translocation in acute rejection after small bowel transplantation in rats.

Acute rejection after small bowel transplantation (SBTx) may facilitate bacterial translocation (BT) and subsequent changes in the liver, spleen, and lungs. This study investigated whether BT occurs after acute rejection and whether this is followed by changes in the structure of the intestine and the phagocytic organs interposed between the gut and the general circulation. Orthotopic SBTx was performed in allogeneic (ALLO) rat-strain combinations (BN-Wistar, n=5). For comparison we used syngeneic SBTx (SYN) (BN-BN, n=6) controls. Animals were sacrificed on postoperative day 7. Mesenteric lymph nodes and portal and caval blood were cultured for aerobes and anaerobes. Escherichia coli beta-galactosidase DNA was assessed by polymerase chain reaction in the blood samples. Intestine, liver, spleen, and lung protein and DNA contents were measured. Histologic changes were graded according to standard criteria of acute rejection. For comparisons we used chi(2) and nonparametric Mann-Whitney test with a threshold of significance of p<0.05. ALLO rats lost more weight after SBTx than SYN rats (-13.02+/-4.39% vs. -8.04+/-5.08% of preoperative weight), although the difference was not significant (ns). A variable degree of graft rejection was histologically demonstrated in all ALLO rats, and DNA/protein content in the graft was significantly higher in this group (0.245+/-0.85 vs. 0.134+/-0.21, p<0.05). Gram-negative enteric bacteria were found in 4/5 ALLO and 4/6 SYN rats (ns), and aerobic Gram-positive bacteria in 2/5 and 3/6 (ns), respectively. Anaerobic growth occurred in mesenteric lymph nodes in one ALLO rat and in the bloodstream in another one. E. coli DNA was isolated in none of the ALLO but in two SYN rats (ns). BT was frequent after SBTx in both syngeneic and allogeneic strain combinations. Contrary to our expectations, BT after SBTx was not higher in ALLO group rats. However, anaerobic germs were isolated only in this group.

Acute Disease↗
PubMed2004

Decrease of parafollicular thyroid C-cells in experimental esophageal atresia: further evidence of a neural crest pathogenic pathway.

Adriamycin-induced experimental esophageal atresia (EA) is often associated with malformations of neural crest (NC) origin, such as abnormal pharyngeal pouch derivatives like the thymus and the parathyroids. The aim of the present study was to examine whether NC-derived thyroid C-cells were abnormal in a rat model. Pregnant rats received intraperitoneally either 2 mg/kg Adriamycin (EA) or vehicle (controls) on days 8 and 9 of gestation. Fetuses were recovered on day 21, and blocks including the trachea and thyroid were fixed in formalin, coronally sectioned at 3-mum widths, and stained with standard hematoxylin and eosin until the largest area of thyroid was reached. From this point on, the 1st, 10th, and 20th slices were immunohistochemically stained with anti-calcitonin antibody. Positively-stained cells in each section of the gland were counted using a computer-assisted image analysis method, and the results were averaged. The distribution of the cells within the gland was assessed as well. Comparisons between EA and control rats were made by nonparametric tests with a significance threshold of p<0.05. The number of C-cells was dramatically reduced in EA animals compared with controls (32.4+/-36 vs. 92.3+/-60.5, p<0.001). Histology of the thyroid was similar in both groups, but the distribution of positive C-cells within the gland followed an abnormal pattern in EA rats. Adriamycin causes a pattern of NC-derived malformations, including a severe decrease in thyroid C-cells accompanied by abnormal distribution or migration patterns. These results represent further evidence of the involvement of NC organogenic control dysregulation in the pathogenesis of EA and its associated malformations. The similarities between the rat model and the clinical picture strongly support investigating other subclinical NC-derived anomalies in patients with EA.

Animals↗
PubMed2004

Critical assessment of the methods used for detection of bacterial translocation.

AIM: Bacterial translocation (BT) can be demonstrated by blood and lymph node cultures and also by polymerase chain reaction (PCR) detection of DNA of enteric bacteria. Aiming at investigating BT after gastrointestinal operations we assessed it on two endpoints after ischemia-reperfusion (IR) or sham operation (SO). METHODS: 2 groups of 200-g Brown Norway male rats were treated as follows: SO animals ( n=12) had laparotomy alone and IR animals ( n=12) had successively 15 min clamping of the portal vein and the mesenteric artery. Half the animals in each group were killed on postoperative (p.o.) day 2 the other half on p.o. day 7. Under sterile conditions regional lymph nodes and vena cava and portal vein blood samples were recovered and cultured for aerobes and anaerobes. Escherichia coli beta-galactosidase DNA was assessed in blood samples by PCR. The findings in the two groups were compared by means of chi(2) tests. RESULTS: Post-hepatic (peripheral blood) BT was detected by cultures of gram-negative bacteria in 16% and 0% of SO and IR animals, respectively, on p.o. day 2 and in 16% and 50% on p.o. day 7. These differences were not significant (ns). E. coli DNA was found in one SO rat. Pre-hepatic BT (portal blood and/or lymph nodes) of gram-negative bacteria was found in 16% and 33%, respectively, on day 2 and in 16% and 16% on day 7 (ns). However, if gram-positive cultures were taken into account, the figures were 66% and 66% on day 2 and 66% and 83% on day 7 (ns). No anaerobes could be cultured. CONCLUSIONS: (1) BT is frequent in surgically manipulated animals. (2) To limit the assessment of BT to Enterobacteriaceae is probably misleading, since consistent amounts of gram-positive bacteria are found in the pre-hepatic territory. (3) PCR tests limited to E. coli DNA alone are likely incomplete. (4) Short periods of vascular clamping do not increase BT on the two endpoints selected in comparison with SO animals.

Animals↗
PubMed2004

The vagus and recurrent laryngeal nerves in experimental congenital diaphragmatic hernia.

BACKGROUND: The etiology of the anatomic and functional abnormalities of the esophagus in infants surviving congenital diaphragmatic hernia (CDH) remains unclear. We showed previously that fetal rats with CDH have malformations of neural crest-derived structures. The aim of this study was to examine the anatomy of the vagus and the recurrent laryngeal nerves, both of neural crest origin, in rats with CDH. METHODS: We used the nitrofen-induced CDH fetal rat model. Nine control fetuses from four dams and nine fetuses with CDH from seven dams were included in this study. Embryos were fixed in formalin and a thoracic block from the larynx to tracheal bifurcation was serially sectioned in the horizontal plane. One in every ten sections was stained with hematoxylin and eosin. The image was digitalized using biological software (TDR-3dbase). Vagus and recurrent laryngeal nerves, trachea, esophagus and the great vessels were examined. In order to obtain the three-dimensional reconstructions, 90-120 consecutive images were used. RESULTS: In comparison with controls there were striking abnormalities of the vagus and the recurrent laryngeal nerves in fetuses with CDH: (1) absence of the left (2/9) or right (2/9) vagus nerves; (2) absence of the left (3/9) or right (3/9) recurrent laryngeal nerves; (3) marked hypoplasia of the trunk of the vagus (2/9); (4) deviations of their normal course and change of normal anatomical relationships into the mediastinum (2/9); and (5) abnormal branching of the lower portion of the vagus (1/9). CONCLUSIONS: Rat fetuses with CDH have anomalies of the vagus and recurrent laryngeal nerves that support the concept of a neural crest involvement in the origin of this malformation. 3-D reconstructions allow a detailed analysis and provide a precise insight into the real anatomy. These observations may explain esophageal motility disorders in CDH.

Animals↗