Anderson Lino Costa

Preoperative diagnosis of pancreatic leiomyosarcoma

SummaryBackground: The low incidence of pancreatic leiomyosarcoma is responsible for the small number of cases correctly diagnosed preoperatively, the tumor being frequently confused with benign pancreatic lesions.Results: We describe a symptom free 52-yr-old male bearing an abdominal mass incidentally found at physical examination. Imaging techniques revealed a nonhomogenous large mass at the head of the pancreas that dislodged the portal vein and the superior mesenteric vein. Increased metabolic activity in the tumor area demonstrated by 18F-fluorodeoxyglicose positron emission tomography scan allowed the diagnosis of a malignant lesion. The patient was operated on and a pylorus preserving pancreatoduodenectomy performed. The pathology diagnosis was a low grade leiomyosarcoma. Immunohistochemistry revealed positivity for vimentin and smooth muscle specific actin. The clinical course was uneventful after 2 yr follow-up. Conclusion: Pancreatic leiomyosarcoma may be preoperatively diagnosed by image techniques and differentiated from benign lesions by means of fluorodeoxyglicose positron emission tomography scanning (FDGPET).

Experimental multivisceral xenotransplantation.

Abstract:  Background:  Organ shortage impairs the proposition of multivisceral transplantation to treat multiple organ failure. Interspecies (xeno) transplantation is a valid solution for organ shortage; however, suitable models of this advance are lacking. We describe an effective model of multivisceral xenotransplantation to study hyperacute rejection.

Immunoglobulin G profile in hyperacute rejection after multivisceral xenotransplantation.

Galvao FHF, Soler W, Pompeu E, Waisberg DR, Mello ES, Costa ACL, Teodoro W, Velosa AP, Capelozzi VL, Antonangelo L, Catanozi S, Martins A, Malbouisson LMS, Cruz RJ, Figueira ER, Filho JAR, Chaib E, D′Albuquerque LAC. Immunoglobulin G profile in hyperacute rejection after multivisceral xenotransplantation. Xenotransplantation 2012; 19: 298–304.

Endoscopic features in a model of multivisceral xenotransplantation

Galvão FHF, Farias AQ, Pompeu E, Waisberg DR, Teixeira ARF, de Mello ES, Lino Costa AC, de Castro Galvão R, Santos VR, Chaib E, Carrilho FJ, D’Albuquerque LAC. Endoscopic features in a model of multivisceral xenotransplantation. Xenotransplantation 2010; 17: 423–428.

Small bowel transplantation in outbred rats

PURPOSE To investigate the clinical evolution of orthotopic small bowel transplantation in outbred rats. METHODS Seventy-two outbred Wistar rats weighting from 250 to 300g were used as donor and recipient in 36 consecutives ortothopic small intestine transplantation without immunosuppression. The graft was transplanted into the recipient using end-to-side aortic and portacaval microvascular anastomosis. Procedure duration, animal clinical course and survival were evaluated. Survival shorter than four days was considered technical failure. Recipients were sacrificed with signs of severe graft rejection or survival longer than 120 days. Necropsies were performed in all recipients to access histopathological changes in the graft. RESULTS Median time for the procedure was 107 minutes. Six recipients (16.7%) presented technical failure. Twenty-seven recipients were sacrificed due to rejection, being nineteen (52.7%) between 7(th) and 15(th) postoperative day and eight (22.2%) between 34(th) and 47(th) postoperative day. Graft histology confirmed severe acute cellular rejection in those recipients. Uneventful evolution and survival longer than 120 days without rejection were observed in three recipients (8.3%). CONCLUSION Intestinal transplantation in outbred rats without immunosuppressant regiment accomplishes variable clinical evolution.

Allogeneic anorectal transplantation in rats: technical considerations and preliminary results.

Fecal incontinence is a challenging condition with numerous available treatment modalities. Success rates vary across these modalities, and permanent colostomy is often indicated when they fail. For these cases, a novel potential therapeutic strategy is anorectal transplantation (ATx). We performed four isogeneic (Lewis-to-Lewis) and seven allogeneic (Wistar-to-Lewis) ATx procedures. The anorectum was retrieved with a vascular pedicle containing the aorta in continuity with the inferior mesenteric artery and portal vein in continuity with the inferior mesenteric vein. In the recipient, the native anorectal segment was removed and the graft was transplanted by end-to-side aorta-aorta and porto-cava anastomoses and end-to-end colorectal anastomosis. Recipients were sacrificed at the experimental endpoint on postoperative day 30. Surviving animals resumed normal body weight gain and clinical performance within 5 days of surgery. Isografts and 42.9% of allografts achieved normal clinical evolution up to the experimental endpoint. In 57.1% of allografts, signs of immunological rejection (abdominal distention, diarrhea, and anal mucosa inflammation) were observed three weeks after transplantation. Histology revealed moderate to severe rejection in allografts and no signs of rejection in isografts. We describe a feasible model of ATx in rats, which may allow further physiological and immunologic studies.

Multivisceral Xenotransplantation: The Effect of Different Dpecies Combination

Multivisceral transplantation is currently an acceptable therapy; however, organ shortage is a major impairment for this practice. Xenotransplantation is promising for organ shortage; but it causes hyperacute rejection (HR) that destroy the graft in few hours and still demand advances to be properly treated. In this report, we compare the HR in three species combinations of multivisceral xenotransplantation. Method Multivisceral grafts (esophagus, stomach, small intestine, colon, liver, pancreas, spleen and kidneys) were recovery and implanted heterotopically in dog-to-pig (n = 5); pig-to-dog (n = 5); rabbit-to-pig (n = 15) combinations. Multivisceral allotransplantation [pig-to-pig (n=5), dog-to-dog (n=4) and rabbit-to-rabbit (n=5)] composed the control group. Three hours after reperfusion, we collected samples from the graft for histopathology. Results HR was visually noted in xenografts around 15 minutes after reperfusion. The autopsy revealed predominance of mild and moderate HR in esophagus and liver in all combination and stomach in pig-to-dog and dog-to-pig combination and severe HR was predominant in stomach, small intestine, colon, pancreas, spleen and kidneys. The occurrence of HR was absent in allografts. IgG fixation was strong in xenografts and absent in allografts. Conclusion The three different models of this experiment are relevant to study HR and achieved similar evolution. HR was less aggressive in esophagus, stomach and liver, while it was severe in small intestine, colon, pancreas, spleen and kidneys. allografts reveled normal appearance or mild reperfusion injury in all organs. Figure. No caption available. Figure. No caption available. Figure. No caption available.

Disseminated toxoplasmosis in a patient with advanced acquired immunodeficiency syndrome

Extracerebral toxoplasmosis, with pulmonary involvement and shock, is a rare form of toxoplasmosis in patients with advanced AIDS. It can mimic pneumocystosis, histoplasmosis, and disseminated tuberculosis, and should be considered in the differential diagnosis of causes of respiratory failure and fulminant disease in this group of individuals, especially in areas where the Toxoplasma gondii infection is highly prevalent and in those without proper use of antimicrobial prophylaxis. We report the case of a 46-year-old male patient who presented to the emergency department with uremia, requiring urgent dialysis. During the laboratorial investigation, the patient had confirmed HIV infection, with a low CD4+ peripheral T-cell count (74 cells/µL). During hospitalization, the patient presented drug-induced hepatitis due to trimethoprim/sulfamethoxazole in a prophylactic dose, requiring interruption of this medication. On the 55th day of hospitalization, the patient developed refractory shock and died. At the autopsy, disseminated toxoplasmosis with encephalitis and severe necrotizing pneumonia were diagnosed, with numerous tachyzoites in the areas of pulmonary necrosis.

Hepatocellular carcinoma may display elevated nestin expression in endothelial cells: experimental study

CONTEXT AND OBJECTIVE Nestin, a class VI intermediate filament protein, is highly expressed in the portal mesenchyme and sinusoidal endothelium of the human fetal liver, but scarcely expressed in adult portal vessel endothelium. During experimental liver regeneration, an increased number of nestin-positive parenchymal cells have been observed in the zone adjacent to the Hering canals. These parenchymal cells are regarded as hepatic stem cells or hepatoblasts, which may be involved in hepatocellular carcinogenesis. In the light of recent reports describing nestin-positive parenchymal cells in hepatocellular carcinoma, we aimed to use this tumor type as a positive control for immunohistochemical detection of nestin. DESIGN AND SETTING Experimental study conducted at a university hospital. METHODS Hepatocellular carcinoma sections from one case were analyzed for nestin expression by immunohistochemistry using confocal microscopy. RESULTS Surprisingly, a conspicuous pattern resembling liver sinusoid-like cytoarchitecture was observed upon nestin staining of endothelial cells. CONCLUSIONS This pattern has not been previously described. The preliminary results shown here suggest that nestin-positive endothelial cells are located in niches of immature or proliferative cells. Moreover, nestin expression in endothelial cells of hepatocellular carcinoma enhances the role of angiogenesis in this tumor type, although the prevalence of this immunohistopathological pattern remains to be determined. Finally, hepatocellular carcinoma is an effective positive control for nestin staining in fluorescent immunohistochemistry.