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In this paper, a method of damage assessment based on neural networks (NNs) is presented and applied to the Steelquake structure. The method is intended to assess the overall damage at each floor in composite frames caused by seismic loading. A neural network is used to calibrate the initial undamaged structure, and another to predict the damage. The natural frequencies of the structure are used as inputs of the NNs. The data used to train the NNs were obtained through a finite element (FE) model. Many previous approaches have exhibited a relatively poor capacity of generalisation. In order to overcome this problem, a FE model more suitable to the definition of damage is tried herein. Further work in this paper is concerned with the validation of the method. For this end, the damage levels of the structure were obtained through the trained NNs from the available experimental modal data. Then, the stiffness matrices of the structure predicted by the method were compared with those identified from pseudo-dynamic tests. Results are excellent. The new FE model definition allows the NNs to have a much better generalisation. The obtained values of the terms of the stiffness matrix of the undamaged structure are almost exact when comparing with the experimental ones, while the absolute differences are lower than 8.6% for the damaged structure. [Copyright &y& Elsevier]

This paper deals with the parametric identification of a small-scale bridge model that was intended to approximately reproduce the transversal dynamic behaviour of its corresponding prototype. This is representative of a typical multi-span continuous-deck irregular bridge. A linear model with viscous damping is proposed to reproduce its dynamic response. The identification is carried out in the time domain using experimental earthquake-induced data and assuming the mass is known. An identification procedure including a genetic algorithm with parallel selection has been developed. In the studied case, the procedure has demonstrated to be robust. It is shown that the model could be improved by using a non linear approach for the dissipative forces.

Objectives: To determine clinical, epidemiological and therapeutic characteristics of pediatric urolithiasis in our institution., Material and Methods: We reviewed retrospectively patients diagnosed with urolithiasis between 1998 and 2010 in our hospital., Results: A total of 32 patients (19 males and 13 females) with a mean age of 4.5 years (SD 1.9) were studied. 72% had a history of metabolic or nephro-urological malformations. The most common presentation was urinary tract infection (53%) and abdominal pain (21%). The diagnosis was made by ultrasound, with compatible X-ray in 18 cases. The most common location was pyelocalyceal level, affecting the left kidney mostly. A 38% had multiple stones with a size of 11 mm medium (3-30 mm). Ureteroscopy was used 16 times for stones in the bladder and distal ureter, with an effectiveness of 75%, and 2 patients required laparoscopic trocar cystotomy for removal. 8 extracorporeal lithotripsy procedures were performed (25% success) and 8 percutaneous nephrolithotomy procedures (37.5% success). In 3 patients we decided to perform a lumbotomy due to the size of the calculi, and, in 1 patient nephrectomy was necessary due to malfunction. The most common complication was lithiasis recurrence in 10 patients, most with multiple stones or metabolic alterations, and favourable outcome for the rest., Conclusions: Pediatric urolithiasis is uncommon, showing an increased incidence in patients with a history of metabolic and urologic pathology; it is important to do additional studies. In the last few years, it has been demonstrated that surgical treatment using minimally invasive procedures is effective and safe.

Introduction: Lymphatic malformations are congenital lesions usually placed in the head and neck, the abdominal location is infrequent., Objectives: Analyze our experience in ALM management., Method: Retrospective study of pediatric patients with ALM from 1996 to 2011. It is a descriptive analysis of clinical, diagnostic and therapeutic features., Results: 10 patients with ALM were treated (6 girls: 4 boys), with a median age of 4.03 years (3 days-13 years). Acute abdomen was the most common presenting feature (40%). Ultrasound was carried out in all these cases, completing the study with CT (9 cases), MRI (1) or both (1). Treatment was surgical, excepting one case that presented infection of the ALM. The approach by laparotomy allowed total resection in all cases, involving bowel resection in 6. The mass was located in small bowel mesentery (6), mesocolon (1), liver (1), and in retroperitoneum (1). The final pathologic diagnosis showed an error in diagnostic imaging of 60%.The mean follow-up was 18 months (SD: 12.8), with not recurrences., Conclusions: ALM often manifests in a non-specific form and it may remain silent. Imaging studies guide the diagnosis, but only the histology provides a definitive result. Total resection is the best option to prevent recurrences and minimize complications.

Introduction: The endoscopic treatment of the ureterocele is a less invasive procedure. Currently, there are only a few published articles regarding the long-term outcomes of this treatment., Material and Methods: We have introduced this technique in our practice since 1995, and have been tracking 15 pediatric patients for long-term evaluation., Results: The average operative age for endoscopic treatment is 19.40 months (1 week-8 years). In 53% of the cases, the diagnosis was made during prenatal screening. In 27% of the cases, the ureterocele was bilateral, and 47% of the patients have a double system. The indication for endoscopic treatment is 66% ureteric obstruction and 34% vesicoureteric reflux. We perform "uncapping" and incision in the two first cases and puncture in the subsequent procedure. The patients were followed for 4 years (7 months-7 years). During this time, two ureteroceles needed a second perforation, out of the seven that continued having reflux, two were treated with quimioprofilaxis and two were treated endoscopically for anti-reflux. Two patients continued to have reflux, and two were diagnosed with renal atrophy and hemiatrophy., Discussion: The endoscopic treatment avoided an open surgical procedure in almost all cases. The need for anti-reflux puncture occurred in 33% of the cases.

Prostate-specific antigen (PSA) is the most commonly used tumour marker for prostate cancer, both in screening and in follow-up. However, there are many false positive increases in the presence of other prostate diseases and, currently, there is no consensus regarding sensitivity and specificity of the PSA test, nor what constitutes the upper limit of normality. We report a case of a 67-year-old patient with metastatic prostate cancer who, with increased level of alkaline phosphatase and normal PSA, showed clinical and radiological evidence of progression of the disease.

The practice of minimally invasive surgery techniques in the retro-peritoneal space presents additional difficulties. Due to the absence of a real cavity and the presence of a dense fat tissue involving the structures, the need for an artificial space to work in is necessary. We present three cases of the retro-peritoneal superior heminephrectomy present in a 3-months, 6-months and a 6-year old children. In all cases a 1 centimeter port for the optique and two 0.5 centimeter ports for the instruments were situated, and the use of harmonic scalpel was satisfactory to remove renal tissue without bleeding. Drainages were unnecessary and all of the children left the hospital within the first 48 post-operative hours. Since 1994, when Figenhans and Clayman communicated the first laparoscopic nephrectomy in children, the technique has been used generally and their forward advances in conventional surgery are now universally accepted. Furthermore, the practice of polar retro-peritoneoscopic heminephrectomy allowed a very precise renal hiliar dissection and an excellent differentiation of each hemirenal tissue, separating the ill kidney and preserving the maximum function possible for the other half-kidney and the adrenal gland.

The progressive advances in Minimally Invasive Surgical Procedures, are applied presently to the surgical treatment of intra-thoracic injuries in children by way of Video-Assisted Thoracic Surgery (VATS) techniques. We present the complete findings of two intra-thoracic masses, in an infant and in a school-aged child, with the use of the VATS technique. The operative technique is detailed in each case. We conclude that the lack of invasiveness and cost-efficiency of VATS the technique, constitute it as being the first choice in the treatment of intra-thoracic masses in children.

We have evaluated 465 patients diagnosed as having vesicoureteral reflux between 1975 and 2000 in our Department. Three hundred cases were treated surgically and 165 received submucosal injection of Teflon as endoscopic procedure. Since 1991, when we introduced the endoscopic technique in our Department, 31 patients required open surgery. The work includes the study of the diagnostic procedures performed in the patients, such as ultrasonography, voiding cystouretrography and renal isotopic gammagraphy. We focused on these patients treated endoscopically. The overall success rate was 97.6% with surgical techniques. Reflux was resolved using the endoscopic procedure in 76% after first injection, 93% after second and 96% after third. We conclude that the submucosal injection of Teflon is an appropriate treatment for most cases of vesicoureteral reflux. The non-invasive procedure requirement, lack of adverse effects and minimal morbidity make it an alternative to medical treatment and open surgery. The future is the search for new biocompatible materials with tissue-augmenting properties as Teflon.

Introduction: Abdominal wall closure is not possible in large congenital defects, even after extensively stretching in to enlarge its capacity. The skin coverage is usually adequate but the aponeurotic defect has to be closed temporally using synthetic patches. The use of these materials leads to increase complication such as infection, fistula formation and extrusion. In addition a second operation is required to remove the material and to perform a definitive closure. The role of fascia lata in reconstruction of abdominal wall is well established as free grafts, pedicled flaps or free flaps. Bank cadaveric fascia lata is used extensively in neurosurgical, ophtalmological, orthopaedic and urogynecological procedures. This is the first description of the use of cadaveric fascia lata for the closure of large abdominal wall defects., Case Reports: We present two cases of congenital diaphragmatic hernia. The first patient was a newborn who presented the impossibility to close the fascia, that was salvaged by a teflón patch. Five months later the wound opened, leaving the mesh exposed that had to be removed. A cadaveric fascia lata patch was used to cover the defect, closing the skin satisfactorily. The second case was a two days newborn. We performed the diaphragmatic closure, and the aponeurotic defect was closed using cadaveric fascia lata., Results: Cosmetic and functional appearance are satisfactory in both cases and no complications have been seen., Conclusion: Fascia lata patches are revascularized in the abdominal wall and incorporates into receptor tissue. They have the following advantages with respect to synthetic materials: First, the risk of complications is lower. Second, their removal is not necessary. Finally, no intraperitoneal adhesions occur. The risks of disease transmission and rejection are minimized by the Centro Comunitario de Transfusiones donor selection and processing of the cadaveric fascia lata.

Crossed testicular ectopia is a rare congenital malformation in which both testis are located in the same hemiscrotum, and is related to an anomaly in normal testicular descent. This entity was first described by Lenhossek in 1886 and posteriorly by Halstead in 1907. Since then, there have been described less than a hundred of cases of this rare congenital malformation. Several ethiopathogenic theories have been proposed, including testicular adherence to mullerian structures, fusion of the wolffian ducts or defective gubemacular development, although none of them has been widely accepted. Usually, clinical sign is an inguinal hernia with empty contralateral hemiscrotum, and sometimes both testis in ipsilateral hemiscrotum. A new case of this pathology is presented.

A case of an open volar scaphoid dislocation is presented. The patient was treated surgically, with open reduction of the scaphoid and pinning to the lunate. After 9 years, good clinical and radiographic results were obtained.

Pneumothorax in newborns and infants can have different etiologies: alveolar disruption following mechanic ventilation or reanimation, surgery for congenital diaphragmatic hernia or esophagus atresia, staphylococcal pneumonia, or thoracic traumas. We studied 105 cases of pneumothorax (96 newborns) treated in our hospital during the last 15 years. Pleural puncture with drainage and antimicrobial therapy were the treatments of choice. Due to early diagnosis and treatment of the pneumothorax and concomitant anomalies mortality was reduced to 17.4%.

Nine cases of colonic atresia, treated in the Departament of Pediatric Surgery of "La Paz" Pediatric Hospital, are reported. They account for 11% of all our intestinal atresias. We review the different etiologic and pathologic theories and classificate our group according to the LOUW and HAYS method. In two cases their digestive anomalies and in one renal anomalies were found to be associated mortality was 11%.