Vincenzo Di Benedetto

Altered 'active' antireflux mechanism in primary vesico-ureteric reflux: a morphological and manometric study

To immunolocate c‐kit‐positive interstitial cells of Cajal (ICCs, known to be responsible for pacemaker activity in human ureters, coordinating ureteric motility) in the intramural ureter of patients with different grades of vesico‐ureteric reflux (VUR), to assess the ureteric histology and correlate these findings with manometric patterns.

Activation of adenosine A2A receptors by polydeoxyribonucleotide increases vascular endothelial growth factor and protects against testicular damage induced by experimental varicocele in rats

In rat experimental varicocele, polydeoxyribonucleotide (PDRN) induces vascular endothelial growth factor (VEGF) production, thereby enhancing testicular function. This may point to a new therapeutic approach in human varicocele.

Altered Cytoskeletal Structure of Smooth Muscle Cells in Ureteropelvic Junction Obstruction

PURPOSE Ureteropelvic junction obstruction is one of the most common causes of hydronephrosis in children. A malfunction of smooth muscle cells is believed to be the underlying mechanism causing obstruction. We investigated the expression of some integrins, talin and β-dystroglycan, considered the main compound of smooth muscle cell cytoskeleton, and active caspase 3 at the level of the ureteropelvic junction obstruction. MATERIALS AND METHODS Specimens were obtained at pyeloplasty in 12 children with ureteropelvic junction obstruction. Six control specimens were obtained during organ explantation. Specimens were divided into renal pelvis, ureteropelvic junction and ureter below the obstruction. Western blot analysis of active caspase 3, and immunofluorescence and polymerase chain reaction analysis were performed for α7A, β1A, α7B and β1D integrins, talin and β-dystroglycan. RESULTS Talin and β-dystroglycan were slightly impaired in ureteropelvic junction obstruction, while α7B and β1D integrins were severely reduced, and α7A, β1A and active caspase 3 were significantly enhanced compared to controls. CONCLUSIONS We demonstrated activation of apoptosis and a critical alteration of cytoskeleton that might explain the altered function and the increased apoptosis in smooth muscle cells in ureteropelvic junction obstruction. The delayed rearrangement of the cytoskeleton of smooth muscle cells in ureteropelvic junction obstruction might be linked to a postnatal splicing from α7A and β1A to α7B and β1D integrins, respectively. This relationship could explain the common clinical scenario of spontaneous improvement of hydronephrosis in children with suspected ureteropelvic junction obstruction.

Spinal anesthesia for inguinal hernia repair in an infant with Williams syndrome: case report

SIR—We take this opportunity to thank Dr Galante et al. for their comments and showing keen interest in our recent article (1). Pediatric anesthesiologists should keep in mind that the pressure at which an air leak is detected is equal to the pressure exerted on the mucosa at the cricoid ring, the narrowest part of trachea (2). Seegobin and van Hasselt (2) showed that in adults continuous elevated pressure above 30 cmH2O compromises mucosal capillary blood flow in the trachea, and they recommended that a cuff inflation pressure of 30 cmH2O should not be exceeded. No values have been reported for children, but it seems logical to set lower safety limits because of lower perfusion pressure in a child’s tracheal mucosa (3). This physiological background may explain why an audible air leak at a threshold pressure of 25 cmH2O or below was related to lower incidence of adverse events in the present study and the original study by Koka et al. (4). However, this physiological explanation is partly in contrast with the study by Mhanna et al. (5) suggesting that air leak test (an audible air leak at 20 cmH2O) has a low sensitivity when used as a screening test to predict postextubation stridor in young children (<7 years old), whereas in older children (‡7 years old) the air leak test may predict postextubation stridor. Based on the assumption the younger the child, the lower the perfusion pressure in the tracheal mucosa, the conclusions of the study by Mhanna et al. (5) should be the other way, the air leak test at a threshold pressure of 20 cmH2O being able to predict postextubation stridor better in younger children. However, it is always important to recognize the possible limitations of all air leak studies that necessitate caution in interpreting the results. The study by Mhanna et al. (5) was a retrospective review with a few patients intubated with cuffed and uncuffed tracheal tubes (TT). In addition, factors such as head position, muscle paralysis and variation between two observers may affect the results of air leak measurement (6,7). The criteria used for definition of outcome measures such as postextubation croup can also affect the findings of the study. According to the findings of our study with siliconized TTs (1) and the original study by Koka et al. (4) 1 with red rubber tubes, an absent air leak at 25 cmH2O pressure indicates the need to replace the existing TT with a smaller one. However, in some patients the air leak with a smaller size TT may be too large to allow proper ventilation and the patient may need to be reintubated with a larger TT. The change of TT may increase trauma to the pharynx and airways. Because of the problems associated with the optimal size of uncuffed TTs, the use of cuffed TTs may be indicated in all the children except preterms. The incidence of postextubation croup reported in patients intubated with cuffed TTs has been low (3). However, pediatric anesthesiologists must be aware of the possible technical complication related to cuffed TTs and type of cuffed TTs available before starting to use them as has been pointed out (3,8). Pertti Suominen M D P h D Penn State Milton S. Hershey Medical Center, Department of Anesthesiology, Hershey, PA, USA (email: psuominen@hmc.psu.edu)

Dextranomer/Hyaluronic Acid Copolymer Implant for Vesicoureteral Reflux: Role of Myofibroblast Differentiation

PURPOSE Dextranomer/hyaluronic acid implantation is associated with a granulomatous inflammatory reaction, replaced by fibrosis. Appearance of myofibroblasts is considered a crucial event in fibrosis, and CD68 positive cells and other factors are implied in their activation. Mast cells are a source of these factors and tryptase can induce fibroblast to express alpha-smooth muscle actin, which is characteristic of myofibroblasts. We evaluated histological changes in refluxing ureters treated with dextranomer/hyaluronic acid and immunolocalized CD68 positive cells, tryptase mast cells and myofibroblasts. MATERIALS AND METHODS We performed histological, histochemical and immunohistochemical analyses in 22 refluxing ureters treated with dextranomer/hyaluronic acid in comparison with 17 refluxing ureters who underwent ureteral reimplantation but did not receive endoscopic bulking agent. We used CD68 antibody for monocytes/macrophages and epithelioid cells, mast cell tryptase mouse antibody for mast cells, and alpha-smooth muscle actin and vimentin antibodies for myofibroblasts. The area of the ureteral lumen in dextranomer/hyaluronic acid treated and untreated ureteral endings was measured. RESULTS Sirius red documented a major grade of histological lesions in dextranomer/hyaluronic acid treated refluxing ureters. CD68 and tryptase mast cell staining showed a significant enhancement of positive cells in dextranomer/hyaluronic acid treated refluxing ureters. Immunostaining for alpha-smooth muscle actin and vimentin displayed a myofibroblastic invasion in dextranomer/hyaluronic acid. Measurement of surface in treated refluxing ureters was significantly less than in untreated refluxing ureters. CONCLUSIONS Our data documented a recruitment of CD68 and tryptase positive cells, abnormal accumulation of collagenous stroma and successive extracellular matrix remodeling through differentiation of myofibroblasts. Myofibroblasts might provoke tissue contraction, decreasing the ureteral diameter and modifying the ureteral length-to-diameter ratio, preventing urine reflux.

Sarcoglycan Subcomplex Expression in Refluxing Ureteral Endings

PURPOSE Functional and structural lesions of ureteral endings seem to alter the active valve mechanism of the ureterovesical junction, causing vesicoureteral reflux. The interaction of the dystroglycan complex with components of the extracellular matrix may have an important role in force transmission and sarcolemma protection, and the sarcoglycan complex is an essential component of the muscle membrane located dystroglycan complex. We performed immunofluorescence and molecular analysis on the expression of sarcoglycan complex subunits. MATERIALS AND METHODS A total of 21 specimens of refluxing ureteral endings were obtained during ureteral reimplantation. Six ureteral ends obtained during organ explantation were used as controls. Immunohistochemical analysis and reverse transcriptase polymerase chain reaction evaluation were performed for alpha, beta, gamma, delta and epsilon-sarcoglycan complex. RESULTS The Spearman test revealed a significant positive correlation between alpha-sarcoglycan complex immunofluorescence intensity and grade of vesicoureteral reflux, while a negative correlation was recorded between epsilon-sarcoglycan complex immunofluorescence intensity and grade of vesicoureteral reflux. CONCLUSIONS Semiquantitative analysis demonstrated a significant grade related impairment of epsilon-sarcoglycan complex coupled with an increased expression of alpha-sarcoglycan complex. This observation suggests that the structural deficiency of the trigonal ureterovesical junction could cause a passive stretching of refluxing urine on the ureter, deranging the multimodular tensegrity architecture of the sarcoglycan subcomplex, or that the sarcoglycan complex could have a key role in the physiopathology of vesicoureteral reflux. In fact, the defect in any of the sarcoglycan complexes results in degeneration of membrane integrity and muscle fiber. An altered configuration of the sarcoglycan complex could explain the structural and functional changes in refluxing ureteral endings. Our observations underline the assumption that primary vesicoureteral reflux might be regarded as a sarcoglycanopathy with marked quantitative deficiency of epsilon-sarcoglycan complex and over expression of alpha-sarcoglycan complex.

Evaluation of Neoadjuvant Chemotherapy Effects on Liver Parenchyma in Resected Pediatric Malignancies

Neoadjuvant chemotherapy for colorectal liver metastases in adults is responsible for chemotherapy-associated liver injury (CALI), characterized by steatosis, steatohepatitis, and sinusoidal obstruction syndrome. These alterations cause delayed operation to reduce the risk of hemorrhage, portal hypertension, and hepatic failure. Children with hepatic malignancies usually receive neoadjuvant chemotherapy prior to surgery. The aim of this study was to evaluate retrospectively whether the CALI occurs in this pediatric population. This study evaluated patients referred since 1996 for hepatic malignancies who received hepatectomy after chemotherapy. Liver resection material was reviewed, in order to investigate the presence of morphological changes compatible with the CALI in the peritumoral hepatic tissue. Twelve patients were recruited. All patients satisfied the inclusion criteria except one who did not receive neoadjuvant chemotherapy. Eleven children underwent surgery 1 month after the last chemotherapy cycle. All are alive disease-free. Histological examination of specimen revealed only mild changes such as diffuse swelling of hepatocytes and focal, mild portal inflammation. Severe hepatic changes such as steatosis, necrosis, or fibrosis were not identified. CALI-related morphological changes were not found in our patients. The absence of the CALI could be attributed to the younger age of patients (possible different response to stress) and/or to the different chemotherapy schedules compared to those in use for adults patients.

A difficult diagnosis of Hodgkin lymphoma due to immune thrombocytopenia

We report a rare clinical presentation of childhood Hodgkin lymphoma with immune thrombocytopenia. Diagnostic biopsy of the abdominal mass was performed after administration of intravenous immunoglobulins, steroids, and platelet transfusion. Concomitant thrombocytopenia complicated the whole diagnosis work up and the initial management of neoplasia.

Substitution of thoracic oesophagus by interposition of a pedicled gastric tube, preserving LES function: clinical and histological follow-up

Assessment of clinical evolution and histological findings in a group of animals experimentally operated on to substitute the thoracic oesophagus with a gastric tube. Six piglets underwent oesophageal replacement with a gastric tube, constructed from the greater curvature of stomach and pedicled on the gastroepiploic vessels, which was interposed between the oesophageal stumps. At follow-up, all animals were found to be growing and eating normally, apart from case no 1 (stenosis of the lower oesophageal anastomosis). Ph-metry showed a neutral pH on the gastric tube. Postmortem histological analysis of the gastric tube and native oesophagus samples did not show any significant lesions, except in case no 1 (inflammation of the gastric tube and upper oesophagus due to food stasis). The technique of substitution of the oesophagus with an interposed pedicled gastric tube can be a breakthrough in existing surgical methods of oesophageal replacement.

An unusual case of severe microcytic anemia.

To the Editor: A 14-year-old boy presented with pallor and asthenia. Laboratory data showed microcytic anemia (Hemoglobin 6.9 g/dL, erythrocytes 4.56 10/mL, mean corpuscular volume 59 fl, reticulocytes 72 10/L, ferritin 1.4 ng/mL, transferrin saturation 1%), microscopic blood and Helicobacter Pylori in stool, and negative markers for celiac disease. Clarithromycin, amoxicillin, and omeprazole, together with oral iron, were prescribed but the boy discontinued the follow-up. One year later, he returned with abdominal pain, vomiting, diarrhea, difficulty in food intake, and weight loss. During the previous year, he had occasionally followed the prescribed treatment with temporary benefits. Physical examination revealed abdominal distension but no palpable masses. Computerized tomographic scan showed parietal thickening of rectum and sigma with a mass measuring 84 33mm whose wall was highlighted after contrast medium injection while its content was hypodense. Two more masses with the same radiologic features were found between the descending colon and the sigma and at the splenic colon flexure. The mucosa was very thin, almost absent in several points. Owing to the high risk of spontaneous perforation, the patient was operated although radical excision was not feasible. Extended hemicolectomy and right colostomy were performed. Another 5 cm long mass was found in continuity with the duodenum and pancreas but due to its position it was unresectable. Macroscopic examination revealed 2 tumor masses: the largest (5 5 cm), found in the transverse colon, was ulcerative/infiltrating, circumferential, and perforating the intestinal wall; the second mass (5.5 3 cm), found in the sigmoidal colon, was polypoid and caused serosal retraction. Another 10 5 cm subserosal mass proved to be metastatic lymph nodes. Histologic final diagnosis was of synchronous poorly differentiated (G3) adenocarcinomas of large bowel with prevalent mucinous pattern; serosal and lymphatic neoplastic invasion; direct infiltration of a seminal vescicle; metastasis in 16 regional lymph nodes out of 46. Tumor nodes metastasis staging was pT4b N2b. We performed the analysis for the mutation of the K-RAS gene but it was not mutated (wild type). There was no familial history of colorectal cancer. After surgery, the patient’s conditions improved, although on the 10th day he had to be reoperated because of peritoneal signs. A duodenal fistula was found and closed, but the boy eventually died on 22nd day for persistence of bile in peritoneum. Colorectal cancer is extremely rare in patients under 20 years of age, with an incidence of 1 to 2 per million, and the prognosis is unfavorable. In the period 2000/2010, Medline database records approximately 300 cases of colorectal cancer in patients aged from 8 to 19 years. Our case confirms the findings reported in literature. The negative prognosis may be related to various factors. These tumors usually present at an advanced local stage, with a great incidence of unfavorable histologic variants. Moreover, the poor knowledge in the occurrence of colorectal cancer in children contributes to delay its diagnosis. Even though microcytic anemia with evidence of fecal blood loss in children is usually due to other reasons, it is advisable to include colorectal cancer in differential diagnosis.