Influence of environmental factors on the tropical peatlands diazotrophic communities from the Southern Brazilian Atlantic Rain Forest.

The tropical peatlands of southern Brazil are essential for the maintenance of the Atlantic Rain Forest, one of the 25 hotspots of biodiversity in the world. Although diazotrophic micro-organisms are essential for the maintenance of this nitrogen limited ecosystem, so far studies have focused only on micro-organisms involved in the carbon cycle. In this work, peat samples were collected from three tropical peatland regions during dry and rainy seasons and their chemical and microbial characteristics were evaluated. Our results showed that the structure of the diazotrophic communities in the Brazilian tropical peatlands differs in the evaluated seasons. The abundance of the genus Bradyrhizobium showed to be affected by rainfall and peat pH. Despite the shifts of the nitrogen-fixing population in the tropical peatland caused by seasonality it showed to be constantly dominated by α-Proteobacteria followed by Cyanobacteria. In addition, more than 50% of nifH gene sequences have not been classified, indicating the necessity for more studies in tropical peatland, since the reduction of N supply in the peatlands stimulates the recalcitrant organic matter decomposition performed by peatland micro-organisms, influencing the C stock.

Functional outcome of autologous anorectal transplantation in an experimental model.

BACKGROUND: Although anorectal transplantation is a challenging procedure, it is a promising option for patients who have completely lost anorectal function or in whom it failed to develop, as in congenital malformations. The paucity of animal models with which to test functional outcomes was addressed in this study of anorectal manometry in rats. METHODS: Wistar rats were assigned randomly to four groups: orthotopic anorectal transplantation, heterotopic transplantation, sham operation, or normal control. Bodyweight and anal pressure were measured immediately before and after operation, and on postoperative days 7 and 14. ANOVA and Tukey's test were used to compare results for bodyweight, anal manometry and length of procedure. RESULTS: Immediately after the procedure, mean(s.d.) anal pressure in the orthotopic group (n = 13) dropped from 31·4(13·1) to 1·6(13·1) cmH2 O (P < 0·001 versus both sham operation (n = 13) and normal control (n = 15)), with partial recovery on postoperative day 7 (14·9(13·9) cmH2 O) (P = 0·009 versus normal control) and complete recovery on day 14 (23·7(12·2) cmH2 O). Heterotopic rats (n = 14) demonstrated partial functional recovery: mean(s.d.) anal pressure was 26·9(10·9) cmH2 O before operation and 8·6(6·8) cmH2 O on postoperative day 14 (P < 0·001 versus both sham and normal control). CONCLUSION: Orthotopic anorectal transplantation may result in better functional outcomes than heterotopic procedures. Surgical relevance Patients with a permanent colostomy have limited continence. Treatment options are available, but anorectal transplantation may offer hope. Some experimental studies have been conducted, but available data are currently insufficient to translate into a clinical option. This paper details functional outcomes in a rat model of anorectal autotransplantation. It represents a step in the translational research that may lead to restoration of anorectal function in patients who have lost or have failed to develop it.

Does anti-hepatitis B virus vaccine make any difference in long-term number of liver transplantation?

BACKGROUND: Hepatitis B virus (HBV) infection is a major cause of morbidity and mortality worldwide. Chronic hepatitis B infection is associated with an increased risk of cirrhosis, hepatic decompensation, and hepatocellular carcinoma. Our aim is to analyze, through a mathematical model, the potential impact of anti-HBV vaccine in the long-term (that is, decades after vaccination) number of LT. METHODS: The model simulated that the prevalence of HBV infection was 0.5% and that approximately 20% of all the liver transplantation carried out in the state of São Paulo are due to HBV infection. RESULTS: The theoretical model suggests that a vaccination program that would cover 80% of the target population would reach a maximum of about 14% reduction in the LT program. CONCLUSION: Increasing the vaccination coverage against HBV in the state of São Paulo would have a relatively low impact on the number of liver transplantation. In addition, this impact would take several decades to materialize due to the long incubation period of liver failure due to HBV.

Prokaryotic communities of acidic peatlands from the southern Brazilian Atlantic Forest.

The acidic peatlands of southern Brazil are ecosystems essential for the maintenance of the Atlantic Forest, one of the 25 hot-spots of biodiversity in the world. In this work, we investigated the composition of prokaryotic communities in four histosols of three acidic peatland regions by constructing small-subunit (SSU) rRNA gene libraries and sequencing. SSU rRNA gene sequence analysis showed the prevalence of Acidobacteria (38.8%) and Proteobacteria (27.4%) of the Bacteria domain and Miscellaneous (58%) and Terrestrial (24%) groups of Crenarchaeota of the Archaea domain. As observed in other ecosystems, archaeal communities showed lower richness than bacterial communities. We also found a limited number of Euryarchaeota and of known methanotrophic bacteria in the clone libraries.

Total pancreatectomy: porcine model for inducing diabetes - anatomical assessment and surgical aspects.

BACKGROUND: The swine is an essential model for carrying out preclinical research and for teaching complex surgical procedures. There is a lack of experimental models describing anatomical and surgical aspects of total pancreatectomy in the pig. MATERIALS AND METHODS: The experiments were performed on 10 white male swine weighing 27-33 kg. The animals were premedicated with midazolam (0.4 mg/kg, i.m.) and ketamine (4 mg/kg, i.m.). Anesthesia was induced with propofol (1-2 mg/kg, i.v.) and was maintained with propofol and fentanyl (0.3 mg and 0.1 µg/kg/min, respectively, i.v.). The surgical period ranged from 44 to 77 min. The pancreas anatomy, and the main arterial, venous and pancreatic duct anatomy were assessed. RESULTS: The pancreas anatomy was composed of 3 lobes, the 'splenic', 'duodenal' and 'connecting' lobe which is attached to the anterior portion of the portal vein. The splenic artery and the junction of the splenic vein and portal vein were divided. The left gastric artery was dissected and separated from its origin at the splenic artery. The head of the pancreas is disposed in a C shape. The pancreas was dissected and liberated from the right portion of the portal vein and the infrahepatic vena cava. The pancreas was separated from the duodenum preserving the pancreaticoduodenal artery, then we performed the total pancreatectomy preserving the duodenum, common bile duct and spleen. CONCLUSION: Total pancreatectomy with duodenum, bile duct and spleen preservation in the pig is feasible and an important instrument for research purposes and teaching surgical technique.

Anorectal transplantation.

BACKGROUND: Anorectal transplantation is a valid procedure for the treatment of anorectal dysfunction; however, the lack of a suitable animal model has hampered the development of this method. We describe a simple technique for anorectal transplantation in the rat and compare this procedure with colostomy. METHODS: The anorectal segment including the skin surrounding the anus were freed by abdominal and perineal dissection. In a heterotopically transplanted group the segment was exteriorized by the formation of an anus through an abdominal incision. In an orthotopically transplanted group the segment was replaced in its original position and reimplanted by suturing. In another group a distal colostomy was performed. A sham-treated control group (simulated surgical procedure) was also included. Changes in behavior, characteristics of the stool, body weight and survival rate were assessed by daily clinical examination. Moribund animals, those with a weight loss of more than 30%, and those surviving at 1 month were killed by an overdose of anesthetic. The results were analyzed using the Mann Whitney, Student's t and chi-squared tests, and p<0.05 was considered significant. RESULTS: Within 4 days after the operation, animals submitted to orthotopic or heterotopic transplantation had achieved normal defecation, body weight gain and clinical evolution similar to the sham-treated group. The overall mortality in these groups was 4.16%. In contrast, colostomized animals showed a high incidence of diarrhea, intestinal obstruction, stress posture and violent behavior (p

Stratifying Mortality in a Model for End-Stage Liver Disease Waiting List: A Brazilian Single-Center Study.

BACKGROUND: The Model for End-Stage Liver Disease (MELD) system reliably predicts mortality in cirrhotic patients. However, the etiology of liver disease and presence of portal vein thrombosis are not directly taken into account in MELD score. Its impact on the outcomes of patients on the waiting list is still unclear. The aim of this study was to investigate mortality and access to transplantation regarding etiology of liver disease and portal vein thrombosis (PVT). METHODS: A total of 465 adult patients on the liver waiting list from August 2015 to August 2016 were followed up until August 2017. Patients were divided into groups according to the etiology of liver disease and presence of PVT. RESULTS: The most frequent etiologies were hepatitis C (26.88%), alcoholic cirrhosis (26.02%) and cryptogenic cirrhosis (10.75%). Death while on the waiting list occurred in 168 patients (36.1%) and was more frequent in nonalcoholic steatohepatitis (NASH, 65.4%) and alcoholic cirrhosis (41.3%). A total of 142 (30.5%) patients underwent transplantation and viral, autoimmune, and biliary diseases showed higher proportion of transplantation (36.3%, 53.8%, and 34%, respectively; P < .01). Mean delta-MELD at the study endpoint was higher in patients with autoimmune hepatitis, biliary diseases, and NASH (8.3 ± 7.2, 8.3 ± 9.1, and 7.5 ± 9.1, respectively; P < .01). A total 77 patients (16.7%) presented PVT. There was no significant difference in outcomes between patients with and without PVT. CONCLUSIONS: Patients with NASH and alcoholic liver disease had higher mortality while on the waiting list, whereas patients with viral and autoimmune hepatitis had higher transplantation rate. Outcomes were not influenced by PVT.

Better Selection Criteria With Prognostic Factors for Liver Transplantation.

BACKGROUND: Liver transplantation has evolved significantly in recent years, with each advancement part of the effort toward increasing patient and graft survival as well as quality of life. The objective of this study was to evaluate the prognostic factors and selection criteria for liver transplantation. METHODS: Our study was a statistical analysis, logistic regression, and survival evaluation of a total of 80 liver transplants that were performed between June 1, 2016 and September 24, 2016. Recipient factors evaluated included age, retransplantation, hemodialysis, cardiac risk, portal vein thrombosis, hospitalization, fulminant hepatitis, previous surgery, renal failure, and Model for End-stage Liver Disease (MELD) score. Donor factors included age, cardiac arrest, acidosis, days in the intensive care unit, steatosis, and vasoactive drug use. RESULTS: Of the 80 patients transplanted, 65 deceased donor liver transplants (DDLTs) and 15 living donor liver transplants (LDLTs) were performed. LDLT overall 1-year patient survival was 77.5% and graft survival 75%, and DDLT overall patient survival was 89.23% and graft survival was 86.15%. On evaluated score criteria analyzed we observed a significant score on recipient (P = .01) and not significant on donor (P =.45). Isolated factors evaluated included recipient age (relative risk [RR] 3.15, 95% confidence interval [CI] 0.89 to 11.09; P = .074), retransplant (RR 4.22, 95% CI 1.36 to 13.1; P = .013), and hemodialysis (RR 4.23, 95% CI 1.45 to 12.31, P = .008). On donor evaluation, we observed moderate and severe steatosis (RR 3.8, 95% CI 0.86 to 16.62; P = .06). CONCLUSION: In conclusion, we demonstrate a relevant model of criteria selection of liver transplant patients that is able to make a better match between the donor and recipient allocation for a better graft and patient survival.

Small bowel and colon transplantation in rats using porto-portal cuff anastomosis.

Portal versus systemic venous drainage and colon grafting are major controversies in the techniques of intestinal transplantation. The rat is the best animal for research in this field. Nevertheless, this model requires complex microvascular anastomoses that are responsible for the high incidence of technical failures. A cuff technique is an easier anastomosis method than a hand-suture. We describe a simplified rat model of small bowel and colon transplantation using a porto-portal cuff anastomosis. DONOR: The entire small bowel, cecum, and ascending colon are harvested on a vascular pedicle, consisting of a long aortomesenteric conduit and portal vein. The right colonic vessels are preserved. The graft is flushed and a cuff device is placed on the end of the portal vein. RECIPIENT: The graft is implanted through an end-to-side aorto-aorta hand-sewn anastomosis. A segment between the first and second jejunal branch is isolated between clamps to insert into the portal cuff. After reperfusion, the recipient's mesentery is divided just below the cuff anastomosis. The recipient jejunum, ileum, and ascending colon are removed en bloc, and the graft is anastomosed in continuity with the remaining naive intestine concluding the operation. This simplified technique surmounts the technical obstacles in rats because it is easily and quickly performed, maintaining the physiological portal drainage, preserving graft ileocecal valve and ascending colon, and reaching acceptable success after a short period of training.

Effects of smoking status and MADRS retardation factor on response to low frequency repetitive transcranial magnetic stimulation for depression.

BACKGROUND: Despite growing evidence supporting the clinical interest of repetitive transcranial magnetic stimulation (rTMS) in treatment-resistant depression (TRD), little is known regarding the effects of clinical and sociodemographic factors on the clinical outcome in patients. METHODS: We retrospectively investigated the effects of clinical (using the 3-factor model of the Montgomery-Åsberg depression rating scale [MADRS] encompassing dysphoria, retardation and vegetative symptoms) and sociodemographic characteristics of participants on clinical outcome in a sample of 54 TRD patients receiving low frequency rTMS (1Hz, 360 pulses) applied over the right dorsolateral prefrontal cortex combined with sham venlafaxine. RESULTS: Responders (n=29) displayed lower retardation baseline scores (13.6±2.9) than non-responders (15.6±2.9; n=25; P=0.02). We also observed a significant difference between the numbers of ex-smokers in responders and non-responders groups; all ex-smokers (n=8) were responders to rTMS (P=0.005). CONCLUSION: Low MADRS retardation factor and ex-smoker status is highly prevalent in responders to low frequency rTMS. Further studies are needed to investigate the predictive value of these factors.

Shortage of Donors for Intestinal Transplantation in São Paulo, Brazil.

BACKGROUND: The number of deceased organ donors has decreased slightly over the past 4 years. Although the pool of intestinal transplantation candidates is relatively small, donor allocation is challenging because of the inability to maintain the donor in a good condition and the complexities involved in making a suitable weight match between donors and recipients. Our goal was to analyze the epidemiologic profile of potential donors based on the organs offered by the regional Organ Procurement Organization from Hospital das Clinicas-USP (OPO/HC-USP) and attempt to estimate possible matches and program viability. METHODS: We retrospectively analyzed information from the OPO/HC-USP database regarding organs offered over the past 7 years as well as patients listed in our program. Data were collected regarding donor characteristics (eg, sex, age, race, body mass index, blood type, cause of death) and medical care details (eg, intensive care unit stay, use of vasopressor agents and antibiotics). RESULTS: In this time period, there were 18,103 brain death notifications in the state of São Paulo; 5,202 (35%) became viable donors, resulting in 5,201 (99%) effectively used livers and kidneys. Most potential donors were male, in their 40s, white, and had blood type O. Only 3 potential donors from OPO/HC-USP would have reached the established minimum criteria for intestinal donation over these 7 years.

Evidence That Anorectal Transplantation Is the Logical Treatment for Serious Anorectal Dysfunction and Permanent Colostomy.

Anorectal dysfunction resulting in fecal incontinence or permanent colostomy is a current public health concern that strongly impairs patient quality of life. Present treatment options for this complex disease are expensive and usually ineffective. Anorectal transplantation is the logical treatment for fecal incontinence and permanent colostomy. This procedure has been clinically effective in a few cases reported in the medical literature. Furthermore, experiments in rats, pigs, and dogs have shown promising results, with functional recovery of the graft. In this article we describe the scientific evidence that anorectal transplantation may be an important option for treating anorectal dysfunction.

Interferon alpha-2B and liver resection to treat multifocal hepatic epithelioid hemangioendothelioma: a relevant approach to avoid liver transplantation.

BACKGROUND: Hepatic epithelioid hemangioendothelioma is a rare malignant tumor of vascular origin with frequent multifocal appearance. Liver resection may cause tumor spread. Liver transplantation has been indicated for unresectable nodules. We hypothesized that adjuvant interferon treatment is effective to prevent metastasis after liver resection. We report a case of multifocal hepatic epithelioid hemangioendothelioma successfully treated with interferon pulse therapy and bilobar hepatic resection. METHODOLOGY: CT scan and magnetic resonance imaging diagnosed three nodules in the liver (segments IV, VI and VII). Histopathology and specific immunostaining of a percutaneous nodule biopsy confirmed the diagnosis of hepatic epithelioid hemangioendothelioma. The treatment protocol included daily interferon alpha 2b 9 weeks before and 1 week after resection of liver segments IV, VI and VII. RESULTS: The postoperative outcome was complicated by a self-limited biliary fistula. The patient remains tumor free at 3 years after liver resection and currently enjoys excellent health. CONCLUSION: Interferon pulse therapy and hepatic resection was a good option to treat multifocal bilobar hepatic epithelioid hemangioendothelioma; it may prevent metastasis dissemination.

Demographic of short gut syndrome: increasing demand is not followed by referral of potential candidates for small bowel transplantation.

BACKGROUND: Despite improvements in small bowel transplantation (SBTx), early referral of patients with irreversible intestinal failure (IF) remains a major obstacle. In this study we evaluated the demand for SBTx among seven surgical pediatric centers located at least 200 km from our center. METHODS: From 1997 to 2001, 640 patients have been treated for neonatal diseases, including 248 who underwent a minor or major intestinal resection. Twenty-four patients with major resections presented with short gut syndrome, requiring total parenteral nutrition (TPN). The greatest demand was in postsurgical neonates with necrotizing enterocolitis, gastroschiesis, onphalocoeles, or midgut volvulus, and in three adults with postradiotherapy arteritis (n = 2) and mesenteric vein thromboses (n = 1). The median length of residual bowel after resection was 20 to 30 cm, without an ileocecal valve. Four patients were referred for SBTx evaluation; three died while awaiting a donor; 20 were not referred, among whom 14 died of TPN complications. RESULTS: Approximately 62 children per year require nutritional support for IF, most of whom develop complications related to TPN. Because many patients who are TPN-dependent develop complications, we believe that early referral would reduce mortality. CONCLUSIONS: Greater medical awareness about the feasibility of SBTx procedures and earlier referral may improve results and quality of life after transplant.

Teleconsultation for cooperative acquisition, analysis and reporting of ultrasound studies.

We have developed a teleconsultation system to support cooperation between doctors at different institutions in the acquisition, analysis and reporting of ultrasound studies. All the relevant activities were supported by the application. The system enabled remote supervision of the ultrasound study as it was being performed, cooperative static image acquisition and analysis, as well as report writing. Cooperative analysis of previously acquired studies was also possible. The system is undergoing evaluation in five hospitals in Portugal.

[Histopathological changes in the small intestine after hypothermic preservation with University of Wisconsin and Euro-Collins solutions. Experimental study]. / Alterações histopatológicas do intestino delgado após preservação hipotérmica com as soluções da Universidade de Wisconsin e Euro-Collins. Estudo experimental.

PURPOSE: The objective of this study is to compare small bowel histopathologic alterations under hypothermic preservation with University of Wisconsin (UW) and Euro-Collins (EC) solutions. METHODS: In 40 Wistar rats (250-300g) the small bowel was microsurgically withdrawn and randomly treated with UW solution or EC solution. Periodic intestinal biopsies were taken from the proximal jejunum and distal ileum each 8 hours after small bowel withdrawing (time 0) until 48 hours. The histopathologic alterations were semiquantitatively classified in 4 degrees of severity and the obtained results were analysed statistically by appropriated tests (p < 0.05). RESULTS: There was a significant increase of the small bowel ischaemic lesions over the time for both experimental groups. The lesions frequency and severity were significantly more increased in the EC group than in the UW group, for jejunal segments at 8 hours, in jejunal and ileal segments at 24 and in jejunal and ileal segments at 48 hours. CONCLUSION: The UW solution did not avoid the development of small bowel ischaemic lesions but, with time, it protected better jejunal and ileal segments, decreasing frequency and severity of histopathological alterations, when compared to EC solution.

Home parenteral nutrition program and referral of potential candidates for intestinal and multivisceral transplantation in a single Brazilian center.

Intestinal failure is a multifaceted condition that may require high-complexity treatment and a multidisciplinary program, including home parenteral nutrition therapy (HPNT) and intestinal transplantation. In this article, we profile a Brazilian single-center experience with 128 cases of HTPN followed for the last 30 years and appraise the referral for potential intestinal and multivisceral transplantation.