Reconfigurable perfect vortex beam generator based on a liquid crystal spiral phase plate.

A transmissive adaptable optical setup to generate a range of perfect vortex beams (PVBs) carrying different topological charges (TC) without using moving parts is presented. The setup is composed of an ad hoc transparent reconfigurable liquid crystal (LC) spiral phase plate (SPP), a refractive axicon and a convergent refractive lens. The LC SPP electrodes are manufactured ablating indium-tin oxide (ITO) glass substrates using direct laser writing (DLW) resulting in a very high fill factor device. In-house tailored electronics drive the 72 LC SPP electrodes giving rise to 72 different configurations with orbital angular momentum. In this work, the generation of PVBs with 36 positive or 36 negative TCs using this optical setup is accomplished.

Computer-supported diagnosis for endotension cases in endovascular aortic aneurysm repair evolution.

An abdominal aortic aneurysm (AAA) is a localized abnormal enlargement of the abdominal aorta with fatal consequences if not treated on time. The endovascular aneurysm repair (EVAR) is a minimal invasive therapy that reduces recovery times and improves survival rates in AAA cases. Nevertheless, post-operation difficulties can appear influencing the evolution of treatment. The objective of this work is to develop a pilot computer-supported diagnosis system for an automated characterization of EVAR progression from CTA images. The system is based on the extraction of texture features from post-EVAR thrombus aneurysm samples and on posterior classification. Three conventional texture-analysis methods, namely the gray level co-occurrence matrix (GLCM), the gray level run length matrix (GLRLM), the gray level difference method (GLDM), and a new method proposed by the authors, the run length matrix of local co-occurrence matrices (RLMLCM), were applied to each sample. Several classification schemes were experimentally evaluated. The ensembles of a k-nearest neighbor (k-NN), a multilayer perceptron neural network (MLP-NN), and a support vector machine (SVM) classifier fed with a reduced version of texture features resulted in a better performance (Az=94.35±0.30), as compared to the classification performance of the other alternatives.

Differential effects of environmental enrichment and isolation housing on the hormonal and neurochemical responses to stress in the prefrontal cortex of the adult rat: relationship to working and emotional memories.

The present study was designed to investigate the modulation of the stress responses by the environmental conditions and its putative neurobiological mechanisms. For that an integrative study on the effects of environmental enrichment and isolation housing on (1) the corticosterone, dopamine and acetylcholine responses to acute restraint stress in the prefrontal cortex (PFC) of the awake rat; (2) the mRNA levels of glucocorticoid receptors (GRs) in the PFC, and (3) the behavioral responses to stress, related to the PFC (habituation to a novel environment, spatial-working memory and inhibitory avoidance response) was performed. Male Wistar rats were maintained from 3 to 6 months of age in two different conditions: enriched (EC) or impoverished (IC). Animals were stereotaxically implanted with bilateral guide cannulae in the PFC to perform microdialysis experiments to evaluate the concentrations of corticosterone, dopamine and acetylcholine. EC animals showed lower increases of corticosterone and dopamine but not of acetylcholine than IC animals in the PFC in response to acute restraint stress (20 min). In the PFC, GR mRNA levels showed a trend towards an enhancement in EC animals. EC reduced the days to learn the spatial working memory task (radial-water maze). Spatial working memory, however, was not different between groups in either basal or stress conditions. Inhibitory avoidance response was reduced in EC rats. The changes produced by EC in the neurochemical, neuroendocrine and behavioral parameters evaluated suggest that EC rats could show a better coping during an acute stress challenge.

Observations on the failure of stent-grafts in the aortic arch.

INTRODUCTION: The results of endovascular stent-grafts in the abdominal aorta and descending thoracic aorta have been encouraging. Expanding the use of thoracic stent-grafts in to the aortic arch has been associated with increasing numbers of complications. Recently isolated cases of stent-graft collapse have been reported. METHODS: This was a multi-centre European case series. Data was collected retrospectively on seven patients from five experienced endovascular centres with thoracic stent-graft collapse. RESULTS: Of the seven patients four were treated for traumatic aortic rupture. Six were male, median age 33 (range 17-54) years. During the ensuing 2 months all patients suffered stent-graft collapse. This was symptomatic in 3 patients and the rest were identified on CT. Endovascular management was possible in 6/7 patients using either a balloon expandable stent (n=6) or further stent-graft (n=1). Two patients had persistent type I endoleak despite treatment. Two of the 7 patients died, both of which presented with symptomatic thoracic stent-graft occlusion. Both deaths were a direct result of stent-graft collapse. CONCLUSIONS: Thoracic stent-graft collapse may be asymptomatic underscoring the importance of stent-graft surveillance. Endovascular management of collapse is possible in most cases using a large balloon expandable stent. Symptomatic collapse is associated with high morbidity and mortality.

Environmental enrichment reduces the function of D1 dopamine receptors in the prefrontal cortex of the rat.

Environmental enrichment produces changes in spontaneous and psychostimulant-induced motor activity. Dopamine in the prefrontal cortex (PFC), through the activation of D1 receptors, has been suggested to play a role in modulating motor activity. The present study investigated the effects of environmental enrichment on spontaneous motor activity, prefrontal acetylcholine release following local D1 receptor stimulation and D1 receptor expression in the PFC. Male wistar rats (3 months of age) were housed in enriched or isolated conditions during 90 days. Animals were then implanted with guide cannulae to perform microdialysis experiments in the PFC. Spontaneous motor activity and acetylcholine extracellular concentrations were monitored simultaneously. Also spontaneous motor activity was measured in an open field. On completion of the experiments, the density of D1 receptors in the PFC was studied by immunocytochemistry. Rats housed in an enriched environment showed significantly lower spontaneous motor activity in the open field compared to isolated animals. Perfusion of the D1 agonist SKF38393 (50 microM; 40 min) in the PFC produced long lasting increases of spontaneous motor activity and of local dialysate concentrations of acetylcholine in both groups of rats. However, increases of both motor activity and acetylcholine concentrations were significantly lower in enriched compared to isolated animals. Moreover, the density of D1 receptors in the PFC was significantly reduced in animals housed in an enriched environment. These results are the first evidence suggesting that environmental enrichment during adult life changes the function of D1 dopamine receptors in the PFC.

[Massive hemorrhage due to esophageal varices as a form of presentation of autoimmune hepatitis]. / Hemorragia masiva por varices esofágicas como forma de presentación de una hepatitis autoinmune.

Autoimmune hepatitis is a necro-inflammatory disease of unknown etiology. An acute or fulminant presentation is rare. We report a 18-year-old man presented with acute variceal hemorrhage. The patient was treated with endoscopic sclerotherapy, somatostatin, balloon tamponade and TIPS. The patient died within a week of massive bleeding and hepatic failure. This patient's history strongly suggests that autoimmune hepatitis can be presented as fulminant hemorrhage. The importance of diagnosis and treatment is emphasized to improve prognosis.

Endovascular repair of abdominal aortic aneurysm in a renal transplant patient.

A 65-year-old man presented with an asymptomatic infrarenal abdominal aortic aneurysm of 6 cm in transverse diameter. Five years before he received a cadaveric renal transplant. The patient also had the following risk factors and associated diseases: arterial hypertension, coronary artery disease, previous myocardial infarction, coronary angioplasty and stent, ileal resection secondary to Chron disease, hepatopathy, hyperlipidemia and hepato-renal cystic disease. The ASA classification was III, IV. Considering previous abdominal operations and risk factors, we decided to repair the aneurysm with a minimal aggression. The aneurysm was successfully approached by an endovascular route implanting a 22x10 bifurcated aorto-iliac endovascular prosthesis. The patient died 13 months later after being diagnosed of enterocolitis by cytomegalovirus complicated with sepsis and lung infection. We consider this less invasive modality of treatment a valid and useful alternative in this high-risk group of patients.

Treatment of popliteal artery aneurysms with uncovered Wallstents.

We report two patients with acutely thrombosed popliteal artery aneurysms that were successfully treated with a combination of thrombolytic therapy and placement of noncovered Wallstents.

[Endovascular treatment of abdominal aorta aneurysms using bifurcated endoprosthesis]. / Tratamiento endovascular de los aneurismas de aorta abdominal con endoprótesis bifurcadas.

OBJECTIVE: To obtain an initial assessment of the implantation technique of bifurcated vascular endoprothesis in the treatment of abdominal aorta aneurysms (AAA). METHODS: Eleven Vanguard type endoprostheses were implanted in eleven patients with infra-renal aortic aneurysm. The technique was performed with surgical approach in one femoral artery, and percutaneously in the other. The procedure was performed with epidural anesthesia. RESULTS: A technical success--i.e., the exclusion of the aneurysm--was obtained in all cases. No technical complications occurred during the procedure. Three patients had low degree contrast leak in the angiographic control immediately after the procedure. Eight patients had low grade fever in the immediate follow-up which resolved with medical therapy, two patients had hematomas in the approach sites, one renal infarction, one ileus for two days, another one for five days, and three patients had lymphatic effusion. During follow-up the patients with leak had to undergo co-axial endoprosthesis implantation. CONCLUSIONS: It is our view that bifurcated vascular endoprostheses offer a valid alternative in the treatment of AAA. The procedure can be performed with epidural anesthesia and sedation, with a low rate of complications. The long term follow-up and the perfecting of the approach and resection systems will ultimately dictate their usefulness in this and other vascular conditions.

[Impact of zidovudine treatment and the pneumocystis carinii prophylaxis in natural history of patients with HIV infection]. / Influencia del tratamiento con zidovudina y de la profilaxis contra Pneumocystis carinii en la historia natural de los enfermos con infección por VIH.

INTRODUCTION: Early use of prophylactic regimens against Pneumocystis carinii and zidovudine therapy, may have modified the natural history of patients with HIV-1 infection. We describe the incidence of opportunistic infections and analize the mortality rate in those patients to check the occurrence of any change in the above mentioned natural history. PATIENTS: Clinical charts of patients with HIV-1 infection attending our hospital are reviewed, from november 1987 to june 1994. RESULTS: We found 200 patients with AIDS, documenting 64 (32%) deaths and 69 (34.5%) patients lost to follow-up. Seven HIV-1 infected patients (3.5%) received primary prophylaxis against Pneumocystis carinii and 17 (8.5%) zidovudine therapy before developing AIDS. Patients with AIDS receiving zidovudine therapy had a higher survival (median 50 months) than those not receiving such therapy (median 17 months; p < 0.001). Ninety one patients with tuberculosis receiving zidovudine therapy had also a higher survival than those not receiving antirretroviral therapy (p < 0.01). Eighty six patients with Pneumocystis carinii pneumonia receiving zidovudine had also a higher survival (p < 0.001). Likewise, patients on zidovudine treatment had a lower reduction on CD4 lymphocyte count. CONCLUSIONS: The spectrum of AIDS-defining illnesses is similar to the whole country. We have not found any difference in the incidence of opportunistic infections, but we observed a trend to reduction in the incidence rate of PCP. The introduction of zidovudine therapy seems to have a positive influence on the survival of AIDS patients. This advantage is highlighted in those patients more immunodeficients at first.

Cragg Endopro System I: early experience. I. Femoral arteries.

PURPOSE: This work describes the early experience with the Cragg Endopro System I. The safety and efficacy of this device in the treatment of atherosclerotic lesions of the femoral arteries are evaluated. MATERIALS AND METHODS: Eleven patients with complex femoral artery lesions were treated. Ten patients presented with femoral artery occlusion and one had a 90% stenosis. All patients had life-style limiting claudication. Associated comorbid states included smoking (n = 10), hypertension (n = 4), hyperlipidemia (n = 5), coronary artery disease (n = 3), and diabetes (n = 1). The stents were dilated to the size of the native artery in the first three patients. The protocol was modified and stents were overdilated by 1 mm in the remaining eight patients. An anticoagulation regimen was used in the first three patients and modified per protocol requirements in the remaining eight. Prophylactics antibiotics were given before the procedure. Follow-up studies included Doppler ultrasound and intravenous and intraarterial digital subtraction angiography. RESULTS: An antegrade femoral approach was used. Stent placement was successful in all patients. The mean lesion length was 9.9 cm (4-18 cm). Mean ankle/brachial index before treatment was 0.65 and increased to 0.87 after treatment. Mean follow-up was 17.2 months, and one patients was lost to follow-up. Complications included sepsis (n = 1), fever (n = 2), severe pain (n = 4), thrombosis (n = 5), and hematoma (n = 2). Stent patency was improved after protocol modifications. Overall primary patency rate was 45% and secondary patency was 56%. CONCLUSION: This early experience with the Cragg Endopro System I shows that recanalization of long femoral occlusions and stent-graft placement is feasible. The primary and secondary patency rates are low and the complication rate is high. Improved patency rates are expected with a more aggressive anticoagulation regimen and stent overdilation.

Effects of perinatal diazepam exposure on the sexually dimorphic rat locus coeruleus.

Diazepam (DZ) administration over prenatal, postnatal, and pre plus postnatal periods altered the normal expression of the morphological sex differences of the LC. Males were affected only by the prenatal exposure and the effect of this exposure produced an increase in the volume and neuron number of male's LC. By contrast, females were affected by both pre and postnatal treatments and the effect of this exposure resulted in a decrease in the volume and neuron number of female's LC. However, pre plus postnatal treatment did not affect female's LC.

Sexual dimorphism of the dopamine-beta-hydroxylase-immunoreactive neurons in the rat locus ceruleus.

Sex differences in the noradrenaline synthesizing neurons of the locus ceruleus (LC) in rat brain were investigated immunocytochemically using an antibody to dopamine-beta-hydroxylase. Female adult rats contained a greater structural volume and average somatic area in the anterior intermediate region of the nucleus compared with males. Whether this difference is related to the endocrine status of the animals, and consequently a functionally distinct population of neurons, is yet to be determined.

Early postnatal diazepam exposure alters sex differences in the rat brain.

The volume and neuron number of the sexually dimorphic accessory olfactory bulb and locus coeruleus are altered by early postnatal exposure (from the day of birth to postnatal day 16) to diazepam. After diazepam treatment, both volume and neuron number were decreased in the male accessory olfactory bulb and in the female locus coeruleus. These results indicate that early postnatal diazepam administration can bear gender-dependent teratogenic effects upon sexually dimorphic nuclei and suggest that endogenous benzodiazepines may be involved in the sexual differentiation of the brain.

Effects of sex steroids on the development of the locus coeruleus in the rat.

The effects of postnatal (on day 1 (D1) after birth) male orchidectomy and female androgenization on the locus coeruleus (LC) are studied. Normal adult female rats show greater LC volume and cell number than males. Testosterone treatment of females on D1 eliminates these differences. However, D1 male orchidectomy does not affect either the volume or the number of cells.