Sergio Ossamu Ioshii

IgA class anti-endomysial and anti-tissue transglutaminase antibodies in relation to duodenal mucosa changes in coeliac disease

Aim: The aim of the present study was to correlate the serological methods of coeliac disease diagnostic tests (IgA EmA and IgA anti‐tTG) with the histological findings of the duodenal mucosa. Methods and Results: Forty‐seven patients were studied and the data were analysed by the Pearson correlation. Seven patients (15%) with normal mucosa were negative for both assays. Forty untreated patients showed 89% agreement between the two serological methods, with all samples (40/40) positive to EmA and 80% (32/40) positive to anti‐tTG. Eight positive samples to EmA, that were negative to anti‐tTG, presented an increased number of intra‐epithelial lymphocytes in the duodenal biopsy and clinical improvement with a gluten‐free diet. Partial or total villous atrophy was detected with EmA titres equal to or higher than 1/10. The correlation coefficient between the two serological methods was R=0.797. Conclusions: Both serological tests correlated very well with histological findings in negative patients and in those with high levels of antibodies. For patients with clinical evidence of CD but with low levels of antibodies, the combination of serological tests and intestinal biopsy is recommended.

Olmesartan severely weakened the development of NASH in an animal model of hypercholesterolemia

BACKGROUND Non-alcoholic fatty liver disease (NAFLD) is characterized by a broad spectrum of liver damage. In a rat model of non-alcoholic steatohepatitis (NASH), olmesartan attenuated steatosis and fibrosis. OBJECTIVE To assess the potential preventive action of olmesartan, an angiotensin II type 1 receptor blocker, on NAFLD in hypercholesterolemic rabbits. METHODS Thirty-four white adult male rabbits were selected. The animals were divided into three groups: group I (GI), control group, 13 rabbits; group II (GII), olmesartan group, 12 rabbits; and group III (GIII), normal group, 9 rabbits. The animals from GI and GII were fed with a specific diet plus 1% cholesterol. Animals from GIII were fed only with a specific diet. The GII animals were treated with olmesartan. RESULTS Steatosis was present in all animals from GI and GII; no steatosis was observed in animals from GIII. When GI and GII where compared, the steatosis had higher scores in GI (p < 0.013). Perisinusoidal and periportal fibrosis occurred in 46.2% of the animals from GI. There was no fibrosis in GII or GIII. Lobular inflammation occurred in 84.6% of the animals from GI. Animals from GII and GIII had no inflammation. The NAFLD activity score was higher in animals from GI when compared to animals from GII and GIII (p < 0.001 for both groups); the NAFLD score was significantly higher in animals from GII when compared to animals from GIII (p < 0.001). CONCLUSIONS In hypercholesterolemic rabbits, olmesartan significantly attenuated hepatic steatosis and prevented the development of lobular inflammation and liver fibrosis. Based on the NAFLD activity score, olmesartan significantly weakened the development of NASH in rabbits fed a high cholesterol diet.

Retalho de submucosa de intestino delgado autólogo para aumento da capacidade da bexiga: estudo experimental em cães

BACKGROUND: Many materials, including organic and synthetic prosthesis, have been described as substitutes of the genitourinary tract. The most commonly used is the ileum, which has many advantages, as easy mobilization and regular vascular pattern. However, the ideal substitute for urinary tract has not been found yet. Ileocystoplasty is not a harmless procedure, and so, investigations are constantly being made to find new substitutes. Small intestinal submucosa (SIS) is an extracelular matrix that can be used as a reabsorbable scaffold for tissue engineering. It allows blood vessels ingrowth, epithelial and connective cells proliferation, induces growing factors production and acquires macro and microscopic characteristics similar to the native tissue. In the urinary tract, previous experimental studies have demonstrated that SIS promotes bladder regeneration. The aim of the present study was to evaluate the biocompatibility of an autologous SIS implant used for bladder augmentation. METHOD: Eight mongrel dogs, weighing between 8 and 15 kg, were prepared for surgery under general anesthesia. A 3cm full-thickness midline cystotomy was performed, followed by immediate augmentation with autologous small intestine submucosa patch graft. On the 30th post-operative day, the animals were re-operated and a fragment of the urinary bladder wall including its patch was removed for histopathogical study. RESULTS: All implants were well incorporated. Macroscopically, SIS could not be distinguished from the native bladder tissue. Mild adherences occurred on the anterior parietal peritoneum. No other macroscopic complications were found. Acute inflammatory response was absent, and chronic inflammatory cells were seen in mild degree. Foreign body reaction was not present, implying satisfactory biological acceptation of the SIS patch graft. Epithelialization was complete in 7/8 implants. Fibroblastic proliferation was moderate. The densitometry of collagen revealed a greater amount of collagen III. Submucosa patch absorption was moderate in most cases. CONCLUSION: We concluded that autologous small intestine submucosa promotes bladder tissue regeneration. Small intestinal submucosa can represent a new option in urinary tract reconstruction.

Enxerto de submucosa porcina no tratamento de lesões duodenais em cães

PURPOSE: To evaluate the biocompatibility and effectiveness of porcine SIS (small intestinal submucosa), when used as a patch to repair a defect on the anterior duodenal wall. METHODS: The experimental study was performed in 8 dogs. A segment of the anterior duodenal wall was removed and the defect was repaired with a patch of porcine intestinal submucosa. On the 120th post operative day the animals were sacrified and the segment of duodenum containing the patch was removed to a macroscopic and microscopic evaluation. RESULTS: There was no infection, suture dehiscence or fistula. The microscopic evaluation showed complete re-epithelization in 75% of the cases, with moderate fibroblastic proliferation in 87, 5% of the cases. CONCLUSION: The porcine SIS used as a patch acts as a tissue substitute for repairing induced lesions in duodenal wall of dogs.

Effect of aging on the healing of colonic anastomoses in rats

PURPOSE: To evaluate the healing of the colonic anastomoses in old and young adult rats. METHODS: Fifty six Wistar rats were allocated in two groups, the young animals aged on average 110 days and the old animals aged average 762 days. Under anesthesia, the rats underwent a midline laparotomy and the colon was sectioned 2 cm above the peritoneal deflection. An end-to-end interrupted one layer colonic anastomosis was performed and the animals sacrificed on the 3rd, 7th, 14th and 21st postoperative days. A 4 cm segment of colon containing the anastomosis was submitted to bursting pressure tests. The paraffin-embedded tissue blocs were sectioned and stained with haematoxylin and eosin and Sirius Red. Histochemical methods such as PCNA, LCA and CD34 were also used. RESULTS: The colonic anastomosis resistance was greater in the old rats group on the 3rd postoperative day (p=0,0000). Collagen concentration was higher in the anastomosis of the young animals on the 14th and 21st postoperative days (p=0,0475, p=0,0346 respectively), with a significantly greater concentration of collagen type I. The concentration of collagen type III, the epithelial lining rate and the angiogenesis were similar in the study groups. CONCLUSION: Despite some differences between the two groups regarding the healing process and considering that failures in the colonic anastomosis wound healing could not be demonstrated, we can concluded that aging itself does not interfere in the wound healing process.

Foco de criptas aberrantes e câncer da junção colorretal: análise da presença de lesões precoces microscópicas na periferia do câncer colorretal e correlação com a expressão da β-catenina e Ki-67

OBJETIVO: Avaliar a presenca de foco de criptas aberrantes (FCA) em mucosa macroscopicamente normal, localizada na periferia de um câncer colorretal (CCR) e correlacionar a progressao tumoral destes FCA para o CCR, por meio da expressao da β-catenina e o Ki-67. METODOS: Utilizou-se 21 especimes cirurgicos contendo adenocarcinoma de juncao retossigmoide. Foram coletadas amostras localizadas a 1 e 5 cm proximal e distal ao tumor, quando possivel, bem como um fragmento da neoplasia. Os FCA foram selecionados. Subsequentemente foi realizado estudo imunoistoquimico com os anticorpos β-catenina e o Ki-67. RESULTADOS: A expressao nuclear da β-catenina nos adenocarcinomas, revelou frequencia de 81%. O Ki-67 apresentou a mesma frequencia. Apesar disso o coeficiente Kappa revelou fraca concordância entre estes anticorpos. Foram observados 20 FCA, sendo que 13 destes focos localizavam-se nas proximidades do tumor. Nenhum dos FCA apresentou expressao da β-catenina nuclear, tampouco para o Ki-67. CONCLUSAO: Nas areas situadas a 1 cm da neoplasia colorretal, foi observada maior concentracao de FCA em relacao as areas situadas a 5 cm do tumor. No entanto, nao se observou correlacao entre a expressao da β-catenina e ki-67 nos colonocitos das criptas aberrantes das areas estudadas, com as celulas neoplasicas do adenocarcinoma.

Tissue expression of retinoic acid receptor alpha and CRABP2 in metastatic nephroblastomas

BackgroundNephroblastoma or Wilms tumor is the most frequent kidney cancer in children and accounts for 98% of kidney tumors in this age group. Despite favorable prognosis, a subgroup of these patients progresses to recurrence and death. The retinoic acid (RA) pathway plays a role in the chemoprevention and treatment of tumors due to its effects on cell differentiation and its antiproliferative, anti-oxidant, and pro-apoptotic activities. Reports describe abnormal cellular retinoic acid-binding protein 2 (CRABP2) expression in neoplasms and its correlation with prognostic factors and clinical and pathological characteristics. The aim of this study was to evaluate the immunohistochemical expression of retinoic acid receptor alpha (RARA) and CRABP2 in paraffin-embedded samples of nephroblastomas via semiquantitative and quantitative analyses and to correlate this expression with prognostic factors.MethodsSeventy-seven cases of nephroblastomas were selected from pediatric oncology services. The respective medical records and surgical specimens were reviewed. Three representative tumor samples and one non-tumor renal tissue sample were selected for the preparation of tissue microarrays (TMA). The Allred scoring system was used for semiquantitative immunohistochemical analyses, whereas a morphometric analysis of the stained area was employed for quantitative evaluation. The nonparametric Mann-Whitney test was used for comparisons between two groups, while the nonparametric Kruskal-Wallis test was used to compare three or more groups.ResultsImmunopositivity for RARA and CRABP2 was observed in both the nucleus and cytoplasm. All histological components of the nephroblastoma (blastema, epithelium, and stroma) were positive for both markers. RARA, based on semiquantitative analyses, and CRABP2, bases on quantitative analyses, exhibited increased immunohistochemical expression in patients with metastasis, with p values of 0.0247 and 0.0128, respectively. These findings were similar to the results of the quantitative analysis of RARA expression, showing greater immunopositivity in tumor samples of patients subjected to pre-surgical chemotherapy. No significant correlation was found with the other variables studied, such as disease stage, anaplasia, risk group, histological type, nodal involvement, and clinical evolution.ConclusionsSemiquantitative and quantitative analyses of the markers RARA and CRABP2 indicate their potential as biomarkers for tumor progression and their participation in nephroblastoma tumorigenesis.

Characteristics of the fibroplasia and collagen expression in the abdominal wall after implant of the polypropylene mesh and polypropylene/polyglecaprone mesh in rats.

PURPOSE To compare fibroplasia and the resistance of the abdominal wall when polypropylene meshes and polypropylene/poliglecaprone are used. METHODS Seventy-seven male Wistar rats were divided into three groups: Control Group (for resistance); Group E (polypropylene mesh); and Group U (polypropylene/poliglecaprone mesh). The animals in Groups E and U had a standard muscular and aponeurotic defect, with integral peritoneum, and correction with the mesh. Measurements were taken 4, 7, 14, 28 and 56 days after surgery. The resistance, and collagen density were studied. RESULTS Resistance on the 56th day was similar in both meshes. The gain in resistance described an ascending curve for the polypropylene mesh and was irregular in the case of the polypropylene/poliglecaprone. Fibroplasia showed a gain in type I and type III collagen in both groups (p<0.001). Collagen III stabilized in the 14th day and collagen I continued to ascend. CONCLUSIONS The gain in resistance of the polypropylene mesh is regular and ascending, whereas the polypropylene/poliglecaprone is not regular. The final resistance of both meshes is similar; the collagen density increases over time, and show the same inflammatory potential.

Impact of hypertension in liver regeneration in rats

PURPOSE To determine the impact of hypertension in liver regeneration, in rats by examining gain in liver mass and the replication of hepatocytes and stellate cells. METHODS Forty Wistar rats were allocated into two groups of twenty, the control and experiment group. The experiment group animals were submitted to induction of renovascular hypertension. A week later, all the animals underwent a partial hepatectomy. Measurements were taken after 24 hours and seven days, when ten animals in each group were euthanized. Thus, four subgroups were obtained. The livers were excised and sent for histopathological analysis. RESULTS The control group had a greater gain in liver mass than the experiment group seven days after partial hepatectomy (p=0.0051). The difference in the activate stellate cell count was not statistically significant following analysis after both 24 hours and seven days (p=1.0). A higher number of dividing hepatocytes was observed in the control group seven days after partial hepatectomy (p=0.0014). CONCLUSION In rats, hypertension had no direct influence on stellate cell replication, but led to a delay in liver mass gain and were shown to be a reduction factor on hepatocyte replication seven days after partial hepatectomy.

Comparative study of fibrosis induced by Marlex®, Parietex Composite®, Vicryl® and Ultrapro® meshes1

PURPOSE To evaluate the fibrosis induced by four different meshes: Marlex®, Parietex Composite®, Vicryl® and Ultrapro®. METHODS Histological cutouts of abdominal wall were analyzed with polarized light 28 days after the meshes implants and colorized by picrosirius to identify the intensity of collagen types I and III, and their maturation index. RESULTS When the four groups were compared, the total collagen area analyzed was bigger in groups A and D, with no difference between them. The collagen type I density was bigger in group A, with an average of 9.62 ± 1.0, and smaller in group C, with an average of 3.86 ± 0.59. The collagen type III density was similar in groups A, B and C, and bigger in group D. The collagen maturation index was different in each of the four groups, bigger in group A with 0.87, group B with 0.66, group D with 0.57 and group C with 0.33 (p = 0.0000). CONCLUSION The most prominent fibrosis promotion in the given meshes was found on Marlex® (polypropylene mesh) and the Parietex Composite® (non-biodegradable polyester); the collagen maturation index was higher in the Marlex® mesh, followed by Ultrapro®, Parietex Composite® and Vicryl® meshes.