Small Bowel Endoscopy Using the Double-Balloon Technique: Four-Year Results in a Tertiary Referral Hospital in Brazil

Background: Double-balloon enteroscopy (DBE) allows evaluation and therapy for various small bowel diseases. In this series the outcome of a 4-year experience in a tertiary hospital school in Brazil is reported. Methods: A total of 457 consecutive DBE were performed in 418 patients from August 2004 to August 2008. 93 patients with several indications, whose aim was not the evaluation of suspected diseases of the small bowel mucosa, were excluded, therefore leaving 364 DBE in 325 patients for analysis. Data were retrospectively collected with regard to clinical, endoscopic findings, therapy and complications. Results: Among the 364 DBE performed in 325 patients, 143/325 were males (44%) and 182/325 females (56%) with a mean age of 48.6 +/- 15.7 years (range 17-89). Mean investigation time was 64 +/- 22 min (range 35-135). The depth of insertion beyond the ligament of Treitz was 230 +/- 85 cm (range 30-500) by the antegrade approach and 140 +/- 75 cm (range 0-320) by the retrograde approach. Total enteroscopy was achieved in 41.66% of the attempts (30 of 72 patients). Overall diagnostic yield was 54.95% (200 of 364 procedures) ranging from 0 to 100% in this series, depending on the indication. Angiodysplasia was the main diagnosis in 24.5% (49 of 200 procedures) and endoscopic treatment, including biopsies, hemostasis, tattooing and polypectomy were performed in 65.38% (238 of 364 procedures). No major complications were reported. Conclusions: DBE is a feasible, safe and well-tolerated procedure allowing endoscopic therapy. Selection of indications increases its diagnostic yield. Copyright (C) 2009 S. Karger AG, Basel

Secondary Lymphangiectasia of the Small Bowel: Utility of Double Balloon Enteroscopy for Diagnosis and Management

Sporadic lymphangiectasias are commonly found throughout the small bowel and are considered to be normal. Not uncommonly, lymphangiectasias are pathologic and can lead to mid-gastrointestinal bleeding, abdominal pain and protein-losing enteropathy. Pathologic lymphangiectasias of the small bowel include primary lymphangiectasia, secondary lymphangiectasia and lymphaticovenous malformations. In this report we present three different cases of small bowel lymphangiectasia detected by double balloon enteroscopy. The patients were diagnosed with South American blastomycosis, tuberculosis and primary small bowel lymphangioma. Copyright (C) 2009 S. Karger AG, Basel

Neoskin development in the fetus with the use of a three-layer graft: an animal model for in utero closure of large skin defects

Objective: To assess the ability of a three-layer graft in the closuse of large fetal skin defects. Methods: Ovine fetuses underwent a large (4 x 3 cm) full-thickness skin defect over the lumbar region at 105 days` gestation (term = 140 days). A bilaminar artificial skin was placed over a cellulose interface to cover the defect (3-layer graft). The skin was partially reapproximated with a continuous nylon suture. Pregnancy was allowed to continue and the surgical site was submitted to histopathological analysis at different post-operative intervals. Results: Seven fetuses underwent surgery. One maternal/fetal death occurred, and the remaining 6 fetuses were analyzed. Artificial skin adherence to the wound edges was observed in cases that remained in utero for at least 15 days. Neoskin was present beneath the silicone layer of the bilaminar artificial skin. Conclusions: Our study shows that neoskin can develop in the fetus using a 3-layer graft, including epidermal growth beneath the silicone layer of the bilaminar skin graft. These findings suggest that the fetus is able to reepithelialise even large skin defects. Further experience is necessary to assess the quality of this repair.

Phrenic nerve diabetic neuropathy in rats: unmyelinated fibers morphometry

We have demonstrated that phrenic nerves` large myelinated fibers in streptozotocin (STZ)-induced diabetic rats show axonal atrophy, which is reversed by insulin treatment. However, studies on structural abnormalities of the small myelinated and the unmyelinated fibers in the STZ-model of neuropathy are limited. Also, structural changes in the endoneural vasculature are not clearly described in this model and require detailed study. We have undertaken morphometric studies of the phrenic nerve in insulin-treated and untreated STZ-diabetic rats and non-diabetic control animals over a 12-week period. The presence of neuropathy was assessed by means of transmission electron microscopy, and morphometry of the unmyelinated fibers was performed. The most striking finding was the morphological evidence of small myelinated fiber neuropathy due to the STZ injection, which was not protected or reversed by conventional insulin treatment. This neuropathy was clearly associated with severe damage of the endoneural vessels present on both STZ groups, besides the insulin treatment. The STZ-diabetes model is widely used to investigate experimental diabetic neuropathies, but few studies have performed a detailed assessment of either unmyelinated fibers or capillary morphology in this animal model. The present study adds useful information for further investigations on the ultrastructural basis of nerve function in diabetes.

Silencing of HTLV-1 gag and env genes by small interfering RNAs in HEK 293 cells

Since the discovery of RNAi technology, several functional genomic and disease therapy studies have been conducted using this technique in the field of oncology and virology. RNAi-based antiviral therapies are being studied for the treatment of retroviruses such as HIV-1. These studies include the silencing of regulatory, infectivity and structural genes. The HTLV-1 structural genes are responsible for the synthesis of proteins involved in the entry, assembly and release of particles during viral infection. To examine the possibility of silencing HTLV-1 genes gag and env by RNA interference technology, these genes were cloned into reporter plasmids. These vectors expressed the target mRNAs fused to EGFP reporter genes. Three small interference RNAs (siRNAs) corresponding to gag and three corresponding to env were designed to analyze the effect of silencing by RNAi technology. The plasmids and siRNAs were co-transfected into HEK 293 cells. The results demonstrated that the expression of the HTLV-1 gag and env genes decreased significantly in vitro. Thus, siRNAs can be used to inhibit HTLV-1 structural genes in transformed cells, which could provide a tool for clarifying the roles of HTLV-1 structural genes, as well as a therapy for this infection. (C) 2011 Elsevier B.V. All rights reserved.

Anti-aversive effects of the atypical antipsychotic, aripiprazole, in animal models of anxiety

Aripiprazole is a unique antipsychotic that seems to act as a partial agonist at dopamine D2-receptors, contrasting with other drugs in this class, which are silent antagonists. Aripiprazole may also bind to serotonin receptors. Both neurotransmitters may play major roles in aversion-, anxiety-and panic-related behaviours. Thus, the present work tested the hypothesis that this antipsychotic could also have anti-aversive properties. Male Wistar rats received injections of aripiprazole (0.1-10 mg/kg) and were tested in the open field, in the elevated plus and T mazes (EPM and ETM, respectively) and in a contextual fear conditioning paradigm. Aripiprazole (1mg/kg) increased the percentage of entries onto the open arms of the EPM and attenuated escape responses in the ETM. In the latter model, the dose of 0.1 mg/kg also decreased the latency to leave the enclosed arm, suggesting anxiolytic- and panicolytic-like properties. This dose also decreased the time spent in freezing in a contextual fear conditioning. No significant motor effects were observed at these doses. The present data support the hypothesis that aripiprazole could inhibit anxiety-related responses. Acting as a partial agonist at dopamine receptors, this drug could effectively treat schizophrenia and, in contrast with most antipsychotic drugs, alleviate aversive states.

Nitric oxide-mediated anxiolytic-like and antidepressant-like effects in animal models of anxiety and depression

The effects of microinjection of the nitric oxide (NO) precursor L-arginine (L-Arg), the NO synthase (NOS) inhibitors N-methyl-L-arginine (L-NAME) and 7-nitroindazole (7-NI), and the cyclic guanosine 3`,5`-monophosphate (cGMP) analog 8-Br-cGMP into the dorsal raphe nucleus (DRN) were assessed in rats using the elevated plus maze (EPM) and the forced swim test (FST). L-Arg (100 and 200 nmol) produced an anxiolytic-like effect in the EPM. 8-Br-cGMP (25 and 50 nmol) dose-dependently increased locomotor activity. In the FST, antidepressant-like effects were produced by L-Arg (50 and 100 nmol) and 8-Br-cGMP (12.5 and 25 nmol). Dual effects were observed with NOS inhibitors L-NAME and 7-NI in both the EPM and FST. While low doses of L-NAME (25 nmol) or 7-NI (1 nmol) induced a selective increase in EPM open arm exploration and a decrease in immobility time in the FST, high doses (L-NAME 400 nmol, 7-NI 10 nmol) decreased locomotor activity. These results show that interference with NO-mediated neurotransmission in the DRN induced significant and complex motor and emotional effects. Further studies are needed to elucidate the mechanisms involved in these effects. (C) 2007 Elsevier Inc. All rights reserved.

Small-World Effect in Epidemics Using Cellular Automata

The spread of an infectious disease in a population involves interactions leading to an epidemic outbreak through a network of contacts. Extending on Watts and Strogatz (1998) who showed that short-distance connections create a small-world effect, a model combining short-and long-distance probabilistic and regularly updated contacts helps considering spatial heterogeneity. The method is based on cellular automata. The presence of long-distance connections accelerates the small-world effect, as if the world shrank in proportion of their total number.