989 resultados para Cyst degeneration
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This article presents a feasibility study with the objective of investigating the potential of multi-detector computed tomography (MDCT) to estimate the bone age and sex of deceased persons. To obtain virtual skeletons, the bodies of 22 deceased persons with known age at death were scanned by MDCT using a special protocol that consisted of high-resolution imaging of the skull, shoulder girdle (including the upper half of the humeri), the symphysis pubis and the upper halves of the femora. Bone and soft-tissue reconstructions were performed in two and three dimensions. The resulting data were investigated by three anthropologists with different professional experience. Sex was determined by investigating three-dimensional models of the skull and pelvis. As a basic orientation for the age estimation, the complex method according to Nemeskéri and co-workers was applied. The final estimation was effected using additional parameters like the state of dentition, degeneration of the spine, etc., which where chosen individually by the three observers according to their experience. The results of the study show that the estimation of sex and age is possible by the use of MDCT. Virtual skeletons present an ideal collection for anthropological studies, because they are obtained in a non-invasive way and can be investigated ad infinitum.
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The parotid lymph nodes of naive and previously infected Balb/c mice were studied after, respectively, infection and re-infection with cercariae of Schistosoma mansoni via the ears. Schistosomula were able to pass through the lymph node by following the lymph flow or by penetrating the veins of the medullary cords. The number of nodal mast cells was higher from day 2 to 6 of primary infection; and from day 5 to 11 of re-infection. The amount of degranulating mast cells was significantly higher at day 4 of infection and at day 1 of re-infection. Eosinophils characterized the nodal inflammatory processes observed after day 5 in both primarily-infected and re-infected mice. However, only in the latter the eosinophils were able to adhere to the larval surface. In primarily-infected mice, no intranodal larva presented signs of degeneration. In contrast, in re-infected animals, some degenerating larvae were found inside eosinophilic infiltrates. The eosinophils reached the nodal tissue by migrating through the high endothelial venules and their collecting veins.
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Lymphocoele is a rare and little known complication with only a handful of reports available. We report two cases of lymphocoele after anterior lumbar surgery that have occurred in two different centres and discuss diagnosis and management options. The first case is that of a 53-year-old male patient undergoing two level anterior lumbar interbody fusion (ALIF) for disabling back pain due to disc degeneration in the context of an old spondylodiscitis. He developed a large fluid mass postoperatively. Fluid levels of creatinin were low and intravenous urography ruled out a urinoma suggesting the diagnosis of a lymphocoele. Following two unsuccessful drainage attempts he underwent a laparoscopic marsupialization. The second case was that of a 32-year-old female patient developing a large fluid mass following a L5 corpectomy for a burst fracture. She was treated successfully with insertion of a vacuum drain during 7 days. Lymphocoele is a rare complication but should be suspected if fluid collects postoperatively following anterior lumbar spine procedures. Chemical analysis of the fluid can help in diagnosis. Modern treatment consists of laparoscopic marsupialization. Lymph vessel anatomy should be borne in mind while exposing the anterior lumbar spine.
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BACKGROUND: Persisting metallic intraocular foreign bodies (IOFB) with a ferrous content have been associated with ocular siderosis and retinal degeneration. We describe two patients in whom a metallic IOFB containing iron was left embedded for many years in the choroid and sclera after having penetrated through the vitreous and the retina. HISTORY AND SIGNS: Two male patients, aged 41 and 48 years, presented with a metallic IOFB sustained during a work accident involving metal tools. THERAPY AND OUTCOME: For the first patient it was deemed unwise to operate, as the IOFB was also lodged very deeply in the choroid and sclera in the inferior temporal quadrant. The second patient underwent pars plana vitrectomy, but the IOFB could not be removed surgically as it was too deeply embedded in the sclera and choroid. After a period of 6 years (Case 1) and 4 years (Case 2) of follow-up, visual acuity remained at 1.0 and the IOFB was encased in a fibrotic capsule in both cases. Full-field and multifocal electroretinograms showed an inter-ocular asymmetry at baseline, which remained stable during the follow-up. CONCLUSIONS: Ocular siderosis may not develop in patients with a deeply embedded metallic IOFB. Regular monitoring of both visual function and the electroretinogram is mandatory when the IOFB is left inside the eye.
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The retinal pigment epithelium (RPE) is constantly exposed to external injuries which lead to degeneration, dysfunction or loss of RPE cells. The balance between RPE cells death and proliferation may be responsible for several diseases of the underlying retina, including age-related macular degeneration (AMD) and proliferative vitreoretinopathy (PVR). Signaling pathways able to control cells proliferation or death usually involve the MAPK (mitogen-activated protein kinases) pathways, which modulate the activity of transcription factors by phosphorylation. UV exposure induces DNA breakdown and causes cellular damage through the production of reactive oxygen species (ROS) leading to programmed cell death. In this study, human retinal pigment epithelial cells ARPE19 were exposed to 100 J/m(2) of UV-C and MAPK pathways were studied. We first showed the expression of the three major MAPK pathways. Then we showed that activator protein-1 (AP-1) was activated through phosphorylation of cJun and cFos, induced by JNK and p38, respectively. Specific inhibitors of both kinases decreased their respective activities and phosphorylation of their nuclear targets (cJun and cFos) and reduced UV-induced cell death. The use of specific kinases inhibitors may provide excellent tools to prevent RPE apoptosis specifically in RPE diseases involving ROS and other stress-related compounds such as in AMD.
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Different toxoplasma antigens were entrapped within liposomes and evaluated, in this form, for their ability to protect Swiss mice against toxoplasma infection: soluble tachyzoite antigen (L/TAg), tissue cyst (L/CAg), tachyzoite plus tissue cyst (L/TCAg) or purified antigen of tachyzoite (L/pTAg). The protein used in L/pTAg was purified from tachyzoites using a stage-specific monoclonal antibody which reacted at a molecular weight of 32 kD in SDS PAGE and silver stain using reduced condition. To compare the immuno-adjuvant action of liposomes and of Freund's Complete Adjuvant (FCA), another group of mice was immunized with soluble tachyzoite antigen (STAg) emulsified in FCA (FCA/TAg). Control groups were inoculated with (STAg) alone, phosphate-buffered saline (PBS), FCA with PBS (FCA/PBS) and empty liposomes (L/PBS). Mice were inoculated subcutaneously with these antigens six, four and two weeks before a challenge with 80 tissue cysts of the P strain of Toxoplasma gondii orally. All mice immunized with or without adjuvant showed a humoral response, as measured by Elisa. However, no correlation was found between antibody titer and protection against the challenge. All mice immunized with L/pTAg or L/TCAg survived (100), whereas 80% and 90% of mice from groups which received respectively PBS or FCA/PBS and L/PBS died. All mice immunized with antigens entrapped within liposomes (L/TAg, L/CAg, L/TCAg and L/pTAg) showed low numbers of intracerebral cysts.
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Purpose: Mutations in the ligand-binding domain (LBD) of NR2E3 cause recessively inherited enhanced short wavelength sensitive (S-) cone syndrome (ESCS), Goldmann-Favre syndrome (GFS) and clumped pigmentary retinal degeneration (CPRD). In addition to ligand binding, the LBD contains also essential amino acid sequences for the oligomerization of nuclear receptors. The aim of our studies is to characterize the impact of mutations in the LBD on receptor oligomerization and transcriptional activity of NR2E3. Methods: The different NR2E3 mutants were generated by QuickChange mutagenesis and analyzed in 293T-based transactivation studies and BRET2 (bioluminescence resonance electron transfer) assays. In silico homology modeling of mutant proteins was also performed using available crystallographic data of related nuclear receptors. Results: The mutants p.W234S, p.A256V, p.A256E, p.L263P, p.R309G, p.R311Q, p.R334G, p.L336P, p.L353V, p.R385P and p.M407K, all located in the LBD, showed impaired receptor dimerization at various degrees. Impaired repressor dimerization as assessed by BRET2 assays did not always correlate with impaired repressor function of NR2E3 as assessed by cell-based reporter assays. There were minor differences of transcriptional activity of mutant proteins on mouse S-opsin (opn1sw), mouse cone arrestin (arr3) and human cone arrestin, suggesting that the effect of LBD mutations was independent of the promoter context. Conclusions: Mutational analysis and homology modeling allowed the characterization of potential oligomerization interfaces of the NR2E3 LBD. Additionally, mutations in NR2E3 LBD may cause recessive retinal degenerations by different molecular mechanisms.
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PURPOSE: We characterized the pupil responses that reflect rod, cone, and melanopsin function in a genetically homogeneous cohort of patients with autosomal dominant retinitis pigmentosa (adRP). METHODS: Nine patients with Gly56Arg mutation of the NR2E3 gene and 12 control subjects were studied. Pupil and subjective visual responses to red and blue light flashes over a 7 log-unit range of intensities were recorded under dark and light adaptation. The pupil responses were plotted against stimulus intensity to obtain red-light and blue-light response curves. RESULTS: In the dark-adapted blue-light stimulus condition, patients showed significantly higher threshold intensities for visual perception and for a pupil response compared to controls (P = 0.02 and P = 0.006, respectively). The rod-dependent, blue-light pupil responses decreased with disease progression. In contrast, the cone-dependent pupil responses (light-adapted red-light stimulus condition) did not differ between patients and controls. The difference in the retinal sensitivity to blue and red stimuli was the most sensitive parameter to detect photoreceptor dysfunction. Unexpectedly, the melanopsin-mediated pupil response was decreased in patients (P = 0.02). CONCLUSIONS: Pupil responses of patients with NR2E3-associated adRP demonstrated reduced retinal sensitivity to dim blue light under dark adaptation, presumably reflecting decreased rod function. Rod-dependent pupil responses were quantifiable in all patients, including those with non-recordable scotopic electroretinogram, and correlated with the extent of clinical disease. Thus, the chromatic pupil light reflex can be used to monitor photoreceptor degeneration over a larger range of disease progression compared to standard electrophysiology.
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A new echinostome cercaria, Cercaria kuwaitae XI sp.n., from the prosobranch gastropod Cerithidea cingulata (Gmelin) from Kuwait Bay is described. The new cercaria is characterized by 23 collar spines and primary excretory tubules with distinct diverticula. The cercaria encysts in the snail host and is similar to those of Acanthoparyphium sp. The surface topography of the redia, cercaria and metacercarial cyst wall is studied by scanning electron microscopy. This is the first echinostome cercaria to be recorded in a gastropod from the Arabian Gulf region.
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Posterior cortical atrophy (PCA) is a group of neurodegenerative dementing disorders characterized by initial predominant visual complaints followed by progressive decline in cognitive functions. The visuospatial and visuoperceptual defects arise from the dysfunction of, respectively, the dorsal (occipito-parietal) and the ventral (occipito-temporal) streams. Clinical symptoms, results of neuropsychological examination, and findings of posterior cerebral atrophy and/or posterior hypoperfusion/hypometabolism contribute to the diagnosis. However, owing to the insidious onset of PCA and the non-specificity of initial symptoms, the diagnosis is often delayed. Specific etiologies include Alzheimer's disease, dementia with Lewy bodies, subcortical gliosis, corticobasal degeneration, and prion-associated diseases. Alzheimer's disease accounts for at least 80 % of PCA cases. Recent research has concentrated on better defining the clinical presentation of PCA, improving neuroimaging analysis, testing new neuroimaging techniques, and developing biological measurements. Selected recent papers on PCA are reviewed in this article.
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Inhibition of vascular endothelial growth factor (VEGF) has become the standard of care for patients presenting with wet age-related macular degeneration. However, monthly intravitreal injections are required for optimal efficacy. We have previously shown that electroporation enabled ciliary muscle gene transfer results in sustained protein secretion into the vitreous for up to 9 months. Here, we evaluated the long-term efficacy of ciliary muscle gene transfer of three soluble VEGF receptor-1 (sFlt-1) variants in a rat model of laser-induced choroidal neovascularization (CNV). All three sFlt-1 variants significantly diminished vascular leakage and neovascularization as measured by fluorescein angiography (FA) and flatmount choroid at 3 weeks. FA and infracyanine angiography demonstrated that inhibition of CNV was maintained for up to 6 months after gene transfer of the two shortest sFlt-1 variants. Throughout, clinical efficacy was correlated with sustained VEGF neutralization in the ocular media. Interestingly, treatment with sFlt-1 induced a 50% downregulation of VEGF messenger RNA levels in the retinal pigment epithelium and the choroid. We demonstrate for the first time that non-viral gene transfer can achieve a long-term reduction of VEGF levels and efficacy in the treatment of CNV.Gene Therapy advance online publication, 27 June 2013; doi:10.1038/gt.2013.36.
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OBJECTIVE: To weight the rod-, cone-, and melanopsin-mediated activation of the retinal ganglion cells, which drive the pupil light reflex by varying the light stimulus wavelength, intensity, and duration. DESIGN: Experimental study. PARTICIPANTS: Forty-three subjects with normal eyes and 3 patients with neuroretinal visual loss. METHODS: A novel stimulus paradigm was developed using either a long wavelength (red) or short wavelength (blue) light given as a continuous Ganzfeld stimulus with stepwise increases over a 2 log-unit range. The pupillary movement before, during, and after the light stimulus was recorded in real time with an infrared illuminated video camera. MAIN OUTCOME MEASURES: The percent pupil contraction of the transient and sustained pupil response to a low- (1 cd/m(2)), medium- (10 cd/m(2)), and high-intensity (100 cd/m(2)) red- and blue-light stimulus was calculated for 1 eye of each subject. From the 43 normal eyes, median and 25th, 75th, 5th, and 95th percentile values were obtained for each stimulus condition. RESULTS: In normal eyes at lower intensities, blue light evoked much greater pupil responses compared with red light when matched for photopic luminance. The transient pupil contraction was generally greater than the sustained contraction, and this disparity was greatest at the lowest light intensity and least apparent with bright (100 cd/m(2)) blue light. A patient with primarily rod dysfunction (nonrecordable scotopic electroretinogram) showed significantly reduced pupil responses to blue light at lower intensities. A patient with achromatopsia and an almost normal visual field showed selective reduction of the pupil response to red-light stimulation. A patient with ganglion cell dysfunction owing to anterior ischemic optic neuropathy demonstrated global loss of pupil responses to red and blue light in the affected eye. CONCLUSIONS: Pupil responses that differ as a function of light intensity and wavelength support the hypothesis that selected stimulus conditions can produce pupil responses that reflect phototransduction primarily mediated by rods, cones, or melanopsin. Use of chromatic pupil responses may be a novel way to diagnose and monitor diseases affecting either the outer or inner retina.
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AIMS/HYPOTHESIS: Diabetic macular edema represents the main cause of visual loss in diabetic retinopathy. Besides inner blood retinal barrier breakdown, the role of the outer blood retinal barrier breakdown has been poorly analyzed. We characterized the structural and molecular alterations of the outer blood retinal barrier during the time course of diabetes, focusing on PKCζ, a critical protein for tight junction assembly, known to be overactivated by hyperglycemia. METHODS: Studies were conducted on a type2 diabetes Goto-Kakizaki rat model. PKCζ level and subcellular localization were assessed by immunoblotting and immunohistochemistry. Cell death was detected by TUNEL assays. PKCζ level on specific layers was assessed by laser microdissection followed by Western blotting. The functional role of PKCζ was then evaluated in vivo, using intraocular administration of its specific inhibitor. RESULTS: PKCζ was localized in tight junction protein complexes of the retinal pigment epithelium and in photoreceptors inner segments. Strikingly, in outer segment PKCζ staining was restricted to cone photoreceptors. Short-term hyperglycemia induced activation and delocalization of PKCζ from both retinal pigment epithelium junctions and cone outer segment. Outer blood retinal barrier disruption and photoreceptor cone degeneration characterized long-term hyperglycemia. In vivo, reduction of PKCζ overactivation using a specific inhibitor, restored its tight-junction localization and not only improved the outer blood retinal barrier, but also reduced photoreceptor cell-death. CONCLUSIONS: In the retina, hyperglycemia induced overactivation of PKCζ is associated with outer blood retinal barrier breakdown and photoreceptor degeneration. In vivo, short-term inhibition of PKCζ restores the outer barrier structure and reduces photoreceptor cell death, identifying PKCζ as a potential target for early and underestimated diabetes-induced retinal pathology.
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Distinct Toxoplasma gondii antigens were entrapped within liposomes and evaluated for their ability to protect Balb/c mice against congenital transmission: soluble tachyzoite antigen (L/STAg), soluble tissue cyst antigen (L/SCAg), soluble tachyzoite plus tissue cyst (L/STCAg) or purified 32kDa antigen of tachyzoite (L/pTAg). Soluble tachyzoite antigen alone in PBS (STAg) or emulsified in Freund's Complete Adjuvant (FCA/STAg) was also evaluated. Dams were inoculated subcutaneously with these antigens 6, 4 and 2 weeks prior to a challenge with four tissue cysts of the P strain of T. gondii orally between 10 and 14 days of pregnancy. Significant diminution differences were observed between the frequency of infected pups born of the dams immunized with the antigens incorporated into liposomes and that of pups born of the dams immunized with antigen emulsified in FCA or non immunized group (p<0.05). There was a significant decrease in the number of pups born dead in the groups L/STAg, L/SCAg and L/pTAg when compared with pups from all other groups (p <0.05). All dams immunized with or without adjuvant showed an antibody response and a proliferation of T-cells. However, no correlation was found between immune response and protection against the challenge.
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WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: The AMS 800 urinary control system is the gold standard for the treatment of urinary incontinence due to sphincter insufficiency. Despite excellent functional outcome and latest technological improvements, the revision rate remains significant. To overcome the shortcomings of the current device, we developed a modern electromechanical artificial urinary sphincter. The results demonstrated that this new sphincter is effective and well tolerated up to 3 months. This preliminary study represents a first step in the clinical application of novel technologies and an alternative compression mechanism to the urethra. OBJECTIVES: To evaluate the effectiveness in continence achievement of a new electromechanical artificial urinary sphincter (emAUS) in an animal model. To assess urethral response and animal general response to short-term and mid-term activation of the emAUS. MATERIALS AND METHODS: The principle of the emAUS is electromechanical induction of alternating compression of successive segments of the urethra by a series of cuffs activated by artificial muscles. Between February 2009 and May 2010 the emAUS was implanted in 17 sheep divided into three groups. The first phase aimed to measure bladder leak point pressure during the activation of the device. The second and third phases aimed to assess tissue response to the presence of the device after 2-9 weeks and after 3 months respectively. Histopathological and immunohistochemistry evaluation of the urethra was performed. RESULTS: Bladder leak point pressure was measured at levels between 1091 ± 30.6 cmH2 O and 1244.1 ± 99 cmH2 O (mean ± standard deviation) depending on the number of cuffs used. At gross examination, the explanted urethra showed no sign of infection, atrophy or stricture. On microscopic examination no significant difference in structure was found between urethral structure surrounded by a cuff and control urethra. In the peripheral tissues, the implanted material elicited a chronic foreign body reaction. Apart from one case, specimens did not show significant presence of lymphocytes, polymorphonuclear leucocytes, necrosis or cell degeneration. Immunohistochemistry confirmed the absence of macrophages in the samples. CONCLUSIONS: This animal study shows that the emAUS can provide continence. This new electronic controlled sequential alternating compression mechanism can avoid damage to urethral vascularity, at least up to 3 months after implantation. After this positive proof of concept, long-term studies are needed before clinical application could be considered.