Characterization of dsRed2-positive cells in the doublecortin-dsRed2 transgenic adult rat retina.

Doublecortin (DCX) is predominantly expressed in neuronal precursor cells and young immature neurons of the developing and adult brain, where it is involved in neuronal differentiation, migration and plasticity. Moreover, its expression pattern reflects neurogenesis, and transgenic DCX promoter-driven reporter models have been previously used to investigate adult neurogenesis. In this study, we characterize dsRed2 reporter protein-expressing cells in the adult retina of the transgenic DCX promoter-dsRed2 rat model, with the aim to identify cells with putative neurogenic activity. Additionally, we confirmed the expression of the dsRed2 protein in DCX-expressing cells in the adult hippocampal dentate gyrus. Adult DCX-dsRed2 rat retinas were analyzed by immunohistochemistry for expression of DCX, NF200, Brn3a, Sox2, NeuN, calbindin, calretinin, PKC-a, Otx2, ChAT, PSA-NCAM and the glial markers GFAP and CRALBP, followed by confocal laser-scanning microscopy. In addition, brain sections of transgenic rats were analyzed for dsRed2 expression and co-localization with DCX, NeuN, GFAP and Sox2 in the cortex and dentate gyrus. Endogenous DCX expression in the adult retina was confined to horizontal cells, and these cells co-expressed the DCX promoter-driven dsRed2 reporter protein. In addition, we encountered dsRed2 expression in various other cell types in the retina: retinal ganglion cells (RGCs), a subpopulation of amacrine cells, a minority of bipolar cells and in perivascular cells. Since also RGCs expressed dsRed2, the DCX-dsRed2 rat model might offer a useful tool to study RGCs in vivo under various conditions. Müller glial cells, which have previously been identified as cells with stem cell features and with neurogenic potential, did express neither endogenous DCX nor the dsRed2 reporter. However, and surprisingly, we identified a perivascular glial cell type expressing the dsRed2 reporter, enmeshed with the glia/stem cell marker GFAP and colocalizing with the neural stem cell marker Sox2. These findings suggest the so far undiscovered existence of perivascular associated cell with neural stem cell-like properties in the adult retina.

[Benign intracranial hypertension. History, clinical features and treatment in a series of 41 patients]. / Hipertensión intracraneal benigna. Antecedentes, clínica y tratamiento en una serie de 41 pacientes.

INTRODUCTION: Benign intracranial hypertension (BIH) is a syndrome characterized by the abnormal elevation of the intracranial pressure with a normal composition of the cerebrospinal fluid (CSF) and in absence of ventriculomegaly or some intracranial expansive lesion. AIM: The present work seeks, by means of the analysis of diagnosed BIH patients to evaluate its epidemic, clinical and therapeutic features. PATIENTS AND METHODS: 87 histories from intracranial hypertension diagnosed patients with normal cerebral CT were reviewed, between 1999 and 2002. 41 BIH patients were selected. RESULTS: The reached results allow us to draw the following profile, a woman (> 70%) of between 21 and 30 years (29%), smoker, obese (59%) with an recent increase of weight (37%) that consults after spending more than three months with headache (89%), alterations of the visual acuity (> 50%) and nauseas with some vomiting (> 40%). In the exploration, it presents with bilateral papilledema (100%), a CSF pressure bigger than 20 cmH2O (40,78 15,55 cmH2O) with normal composition, without alterations in the neuroradiological study results. CONCLUSION: The treatment with acetazolamide was favourable (51,2%), being definitive (70%) the lumbar peritoneal shunt when it is specified (30,7%), being improved these figures in those patients with a smaller pressure of the CSF in the moment of the diagnosis (p<0,035).

Mesenteric angioplasty in the treatment of chronic intestinal ischemia.

PURPOSE: This study was undertaken to determine the safety and efficacy of percutaneous transluminal angioplasty (PTA) in the treatment of chronic mesenteric ischemia (CMI) in very high-risk surgical patients. METHODS: Twenty-four focal mesenteric stenoses treated from 1984 to 1994 by PTA in 19 patients with CMI were reviewed. All 19 patients were considered poor surgical candidates. Seventeen patients had classic symptoms of CMI, and two patients had atypical abdominal complaints. Vessels dilated included the superior mesenteric artery (18), celiac artery (3), inferior mesenteric artery (1), aorta-superior mesenteric artery vein graft (1), and aorta-splenic artery vein graft (1). Complete follow-up was possible in all patients, with the exception of one patient who had no symptoms when last seen 17 months after the procedure. RESULTS: PTA was technically successful in 18 of 19 patients (95%) and 23 of 24 stenoses (96%). The lone technical failure resulted in superior mesenteric artery dissection with thrombosis and bowel infarction; the patient died despite emergent laparotomy and revascularization (mortality rate, 5%). Complete symptomatic relief was attained in 15 patients (79%), with follow-up showing continued relief of symptoms for a mean of 39 months (range, 4 to 101 months). Partial symptomatic relief was attained in three patients. Recurrent symptoms developed in three patients (20%) at a mean interval of 28 months (range, 9 to 43 months). Repeat PTA performed in two patients provided good technical results and relief from clinical symptoms. One patient had a symptomatic axillary sheath hematoma that required surgical decompression. CONCLUSIONS: Mesenteric PTA is a valuable treatment option in patients who have CMI and are considered very high operative risks. The initial technical success rate is excellent, with the majority of patients having complete symptomatic improvement and continued relief of symptoms at short-term follow-up.

Use of stents covered with polytetrafluoroethylene in experimental abdominal aortic aneurysm.

PURPOSE: To establish the effectiveness of covered stents in the treatment of aortic aneurysms, to investigate the histopathologic healing patterns of the device, and to determine the long-term endurance and integrity of modified polytetrafluoroethylene (PTFE). MATERIALS AND METHODS: Experimental aneurysms were created in dogs by enlarging the aortic lumen with a patch of abdominal fascia. After 5 months, eight animals underwent an endoluminal bypass. The bypass device consisted of a 6-cm-long stent covered with thin PTFE. After surgery, the animals were killed at 3, 6, and 12 months in groups of three, three, and two, respectively. Specimens were processed for luminal surface studies and cross-sectional histologic study. Explanted PTFE material was analyzed for its physical characteristics and performance and was compared with retained control samples. RESULTS: Before the animals were killed, aortography showed patent bypass conduits in all animals, although two of eight had leaks into the aneurysmal sac. Endothelialized neointima largely covered the luminal surface of the PTFE stent. The percentage of prosthetic surface covered by tissue did not change from 3 months to 1 year. Physical testing of the explanted PTFE material showed no structural deterioration and no change in the internodal distance. Thickness and axial tensile strength varied 12% and 17% from controls, respectively. CONCLUSION: Thin-walled PTFE seems to have physicochemical characteristics that make this material adequate for endovascular use. Though limited, this study supports the establishment of preliminary clinical evaluation of metallic stents combined with PTFE for the treatment of abdominal aortic aneurysm.

Dissection of the external iliac artery in highly trained athletes.

We report a series of four acute external iliac artery dissections occurring in three patients within days of completion of ultraendurance athletic events. Acute dissection of the external iliac artery in highly trained athletes after competition has not been previously documented. A retrospective review of three cases was performed with subsequent follow-up, including imaging and hemodynamic measurements. Dissection was suspected on the basis of duplex imaging results in one case, and arteriography confirmed dissection in all cases. All patients were endurance athletes over the age of 40 years. One patient was found to have bilateral lesions. Treatment in two cases was initiated with percutaneous transluminal angioplasty, one with a successful result and subsequent Plamaz stent placement. In the other case percutaneous transluminal angioplasty was unsuccessful, and operative repair was required with the placement of a graft. The final patient who had bilateral involvement was treated conservatively. At a mean follow-up of 32 months, there have been no complications, and all patients have normal resting hemodynamics. Follow-up duplex imaging shows healing of the dissections in the untreated patient. Histopathologic study in the patient treated with operation disclosed dissection in an otherwise normal arterial wall. Highly trained athletes over the age of 40 are susceptible to external iliac artery dissection, and successful treatment has been achieved by surgical, endovascular, and conservative therapies.

Percutaneous aortic stent placement for life threatening aortic rupture due to metastatic germ cell tumor.

Patients with testicular carcinoma frequently present with advanced disease and symptoms resulting from metastatic lesions. We report an unusual case of successful emergency management of a massive rupturing aortic pseudoaneurysm midway through systemic chemotherapy for stage III germ cell tumor by percutaneous trans-luminal placement of an aortic bypass stent-graft. Unstable hemorrhage was controlled, allowing our patient to complete chemotherapy and undergo elective retroperitoneal lymph node dissection with resection of the pseudoaneurysm and residual disease after normalization of tumor markers. Final pathological evaluation revealed only fibrosis in the resected tissue. Followup angiography demonstrated a patent stent-graft and the patient was without evidence of disease 1 year after retroperitoneal lymph node dissection.

Intraluminal bypass of abdominal aortic aneurysm: feasibility study.

This study evaluated the feasibility of treatment of abdominal aortic aneurysm (AAA) by means of intraluminal bypass. Artificial aortic aneurysms with fusiform Dacron conduits were created at surgery , a weft-knit Dacron tube with balloon-expandable stents attached at both ends was inserted transfemorally through a 14-F introducer sheath and expanded at the aneurysmal level by means of inflation of a coaxial balloon. The transluminal bypass successfully excluded the aneurysmal lumen immediately after placement. In two dogs, a postplacement aortogram revealed torsion of the graft that caused early occlusion. The six other dogs had a patent bypass at 6 months follow-up. Four of these dogs had evidence of kinking of the graft as a result of shrinkage of the prosthetic aneurysm. Histopathologic studies revealed that endothelialization was complete on the stents and partial on the graft surface. It is concluded that transluminal bypass of AAA is feasible in the dog model.

Variceal hemorrhage associated with portal vein thrombosis: treatment with a unique portal venous stent.

A patient with an uncommon cause of portal venous hypertension, pancreatitis, is depicted. The patient had an equally uncommon pattern of symptoms and signs consisting of abdominal pain and lower gastrointestinal hemorrhage caused by colonic varices. A unique treatment, with angiographic placement of an expandable intraluminal stent within the portal vein, was employed to reopen the portal venous system and reduce portal pressure. Relief of bleeding was accomplished and sustained for more than 1 year.