932 resultados para corneal stroma
Resumo:
In the current study perfusions of an isolated cotyledon of term placenta using standard medium were compared to medium containing xanthine plus xanthine oxidase (X+XO), which generates reactive oxygen species (ROS). A time-dependant increase in the levels of different cytokines (TNF-alpha, IL-1ss, IL-6, IL-8 and IL-10) was observed between 1 and 7h with more than 90% of the total recovered from the maternal compartment with no significant difference between the 2 groups. For 8-iso-PGF2alpha 90% of the total was found in the fetal compartment and a significantly higher total release was seen in the X+XO group. Microparticles (MPs) isolated from the maternal circuit were identified by flow cytometry as trophoblastic sheddings, whereas MPs from the fetal circuit were predominantly derived from endothelial cells. More than 90% of the total of MPs was found in the maternal circuit. The absolute amount of the total as well as the maternal fraction were significantly higher in the X+XO group. Immunohistochemistry (IHC) of the perfused tissue revealed staining for IL-1beta of villous stroma cells, which became clearly more pronounced in experiments with X+XO. Western blot of tissue homogenate revealed 2 isoforms of IL-1beta at 17 and 31kD. In X+XO experiments there was a tendency for increased expression of antioxidant enzymes in the tissue. Western blot of MPs from the maternal circuit showed increased expression of antioxidant enzymes in the X+XO group and for IL-1beta only the 17kD band was detected. In vitro reperfusion of human placental tissue results in mild tissue injury suggestive of oxidative stress. In view of the increased generation of ROS in perfused tissue with further increase under the influence of X+XO, the overall manifestation of oxidative stress remained rather mild. Preservation of antioxidant capacity of human placental tissue could be a sign of integrity of structure and function being maintained in vitro by dual perfusion of an isolated cotyledon. The observed changes resemble findings seen in placentae from preeclampsia.
Resumo:
Endometriosis corresponds to ectopic endometrial glands and stroma outside the uterine cavity. Clinical symptoms include dysmenorrhoea, dyspareunia, infertility, painful defecation or cyclic urinary symptoms. Pelvic ultrasound is the primary imaging modality to identify and differentiate locations to the ovary (endometriomas) and the bladder wall. Characteristic sonographic features of endometriomas are diffuse low-level internal echos, multilocularity and hyperchoic foci in the wall. Differential diagnoses include corpus luteum, teratoma, cystadenoma, fibroma, tubo-ovarian abscess and carcinoma. Repeated ultrasound is highly recommended for unilocular cysts with low-level internal echoes to differentiate functional corpus luteum from endometriomas. Posterior locations of endometriosis include utero-sacral ligaments, torus uterinus, vagina and recto-sigmoid. Sonographic and MRI features are discussed for each location. Although ultrasound is able to diagnose most locations, its limited sensitivity for posterior lesions does not allow management decision in all patients. MRI has shown high accuracies for both anterior and posterior endometriosis and enables complete lesion mapping before surgery. Posterior locations demonstrate abnormal T2-hypointense, nodules with occasional T1-hyperintense spots and are easier to identify when peristaltic inhibitors and intravenous contrast media are used. Anterior locations benefit from the possibility of MRI urography sequences within the same examination. Rare locations and possible transformation into malignancy are discussed.
Resumo:
Steady-state hematopoiesis and hematopoietic transplantation rely on the unique potential of stem cells to undergo both self-renewal and multilineage differentiation. Fetal liver (FL) represents a promising alternative source of hematopoietic stem cells (HSCs), but limited by the total cell number obtained in a typical harvest. We reported that human FL nonobese diabetic/severe combined immunodeficient (NOD/SCID) repopulating cells (SRCs) could be expanded under simple stroma-free culture conditions. Here, we sought to further characterize FL HSC/SRCs phenotypically and functionally before and following culture. Unexpanded or cultured FL cell suspensions were separated into various subpopulations. These were tested for long-term culture potential and for in vivo repopulating function following transplantation into NOD/SCID mice. We found that upon culture of human FL cells, a tight association between classical stem cell phenotypes, such as CD34(+) /CD38(-) and/or side population, and NOD/SCID repopulating function was lost, as observed with other sources. Although SRC activity before and following culture consistently correlated with the presence of a CD34(+) cell population, we provide evidence that, contrary to umbilical cord blood and adult sources, stem cells present in both CD34(+) and CD34(-) FL populations can sustain long-term hematopoietic cultures. Furthermore, upon additional culture, CD34-depleted cell suspensions, devoid of SRCs, regenerated a population of CD34(+) cells possessing SRC function. Our studies suggest that compared to neonatal and adult sources, the phenotypical characteristics of putative human FL HSCs may be less strictly defined, and reinforce the accumulated evidence that human FL represents a unique, valuable alternative and highly proliferative source of HSCs for clinical applications.
Resumo:
Objective: Feline odontoclastic resorptive lesions (FORL) are common in domestic cats. The disease is painful, and leads to root resorption and replacement by bone, and tooth loss. The cause of this non-curable disease has not been established. The present study focused on the periodontal ligament (PL) in clinically and histologically healthy teeth and in teeth exhibiting various degrees of FORL. Methods: A total of 176 tissue blocks from 29 teeth was available for light and transmission electron microscopy. An antibody against osteopontin (OPN) was used for high-resolution immunocytochemistry, since this protein is involved in bone remodeling, cell adhesion, and inflammation. Results: A partial low cell number and an occasional translucent perivascular zone characterized the PL in healthy looking teeth. In teeth exhibiting small or initial FORL, the perivascular hyalinization was more pronounced, cell number was reduced, and widened channels connected the PL with the alveolar bone. In teeth exhibiting severe forms of FORL, the PL tissue was drastically affected. PL regions with massive tissue destruction were characterized by a lack of both cells and extracellular matrix, while other regions were replaced by bone marrow stroma. OPN labeling was restricted to the PL-facing matrix portions of bone and cementum. Conclusion: PL alterations seem to be a common feature in feline teeth. PL degeneration may initially be associated with vasculitis and appeared to increase with the severity of FORL. Since the PL did not recover and bone marrow stroma occupied the degenerated PL, ankylosis and replacement resorption are regarded as unavoidable sequelae.
Resumo:
The rare occurrence of angiosarcoma in postmastectomy upper-limb lymphedema with magnetic resonance (MR) imaging is discussed. Unfamiliarity with this aggressive vascular tumor and its harmless appearance often leads to delayed diagnosis. Angiosarcoma complicating chronic lymphedema may be low in signal intensity on T2-weighting and short tau inversion recovery (STIR) imaging reflecting the densely cellular, fibrous stroma, and sparsely vascularized tumor histology. Additional administration of intravenous contrast medium revealed significant enhancement of the tumorous lesions. Awareness of angiosarcoma and its MR imaging appearance in patients with chronic lymphedema may be a key to early diagnosis or allow at least inclusion in the differential diagnosis.
Resumo:
BACKGROUND: Histopathologic features of the capsule may have an impact on the recurrence rate of pleomorphic adenomas. METHODS: Retrospective (n = 154) and prospective (n = 64) histologic analysis of the capsular characteristics such as incompleteness, tumor penetration, pseudopodia, and satellite tumors of 218 pleomorphic adenomas. RESULTS: In 160 of the 218 (73%) pleomorphic adenomas, 1 or more capsular characteristics such as incomplete capsule (33%), capsule penetration (26%), pseudopodia (40%), and satellite nodules (13%) were detected. Incomplete capsule and satellite tumors were most frequently seen in the stroma-rich (myxoid) subtype. Capsular penetration and pseudopodia were significantly more common in the prospective group than in the retrospective group (p < .05/<.05). CONCLUSION: Pseudopodia and satellite tumors were more common than reported in the literature. If left in the surrounding salivary gland tissue at surgery, they can lead to recurrences of pleomorphic adenomas of the parotid gland.
Resumo:
PURPOSE: To evaluate the expression and presence of surfactant protein (SP) A and SP-D in the lacrimal apparatus, at the ocular surface, and in tears in healthy and pathologic states. METHODS: Expression of mRNA for SP-A and SP-D was analyzed by RT-PCR in healthy lacrimal gland, conjunctiva, cornea, and nasolacrimal ducts as well as in a spontaneously immortalized conjunctival epithelial cell line (HCjE; IOBA-NHC) and a SV40-transfected cornea epithelial cell line (HCE). Deposition of SP-A and SP-D was determined by Western blot, dot blot, and immunohistochemistry in healthy tissues, in tears, aqueous humor, and in sections of different corneal abnormalities (keratoconus, herpetic keratitis, and Staphylococcus aureus-based ulceration). Cell lines were stimulated with different cytokines and bacterial components and were analyzed for the production of SP-A and SP-D by immunohistochemistry. RESULTS: The presence of SP-A and SP-D on mRNA and protein levels was evidenced in healthy lacrimal gland, conjunctiva, cornea, and nasolacrimal duct samples. Moreover, both proteins were present in tears but were absent in aqueous humor. Immunohistochemistry revealed the production of both peptides by acinar epithelial cells of the lacrimal gland and epithelial cells of the conjunctiva and nasolacrimal ducts, whereas goblet cells revealed no reactivity. Healthy cornea revealed weak reactivity on epithelial surface cells only. In contrast, SP-A and SP-D revealed strong reactivity in patients with herpetic keratitis and corneal ulceration surrounding lesions and in several immigrated defense cells. Reactivity in corneal epithelium and endothelium was also seen in patients with keratoconus. Cell culture experiments revealed that SP-A and SP-D are produced by both epithelial cell lines without and after stimulation with cytokines and bacterial components. CONCLUSIONS: These results show that SP-A, in addition to SP-D, is a peptide of the tear film. Based on the known direct and indirect antimicrobial effects of collectins, the surfactant-associated proteins A and D seem to be involved in several ocular surface diseases.
Resumo:
BACKGROUND: An age-controlled comparison concerning patient satisfaction and electrical performance of microfibres (DTL) and rigid contact lens (Henkes) corneal ERG electrodes was carried out. METHODS: 36 test persons underwent complete ophthalmological examination and were equally distributed into 3 age groups. Electroretinograms were recorded according to ISCEV standards. Randomly, in one eye a Henkes electrode was used and in the other eye a DTL electrode. Amplitudes of a- and b-waves and implicit times were measured and compared for the two electrode types. RESULTS: 34 of 36 test persons preferred DTL electrodes. Electrical performance concerning b-wave amplitudes was comparable. Statistically significant differences were detected only for scotopic combined cone-rod stimulation in the age groups 20 - 40 and 41 - 60 years between the different electrodes. Other recordings did not show differences. A statistically significant reduction of signal amplitudes with age was detected for scotopic isolated rod signals and combined cone-rod signals. Significance level was p < 0.05. No conjunctival or corneal erosions were found after ERG recordings for either electrode. CONCLUSIONS: Electrical performance is comparable between electrodes. For scotopic stimulations age was a significant influencing factor for signal amplitude and should be respected for normative values. DTL electrodes were preferred by the vast majority of patients. No adverse clinical effects were observed for either electrode. DTL electrodes should be preferred due to hygienic reasons (single use) and patient comfort.
Resumo:
BACKGROUND: Several conversion tables and formulas have been suggested to correct applanation intraocular pressure (IOP) for central corneal thickness (CCT). CCT is also thought to represent an independent glaucoma risk factor. In an attempt to integrate IOP and CCT into a unified risk factor and avoid uncertain correction for tonometric inaccuracy, a new pressure-to-cornea index (PCI) is proposed. METHODS: PCI (IOP/CCT(3)) was defined as the ratio between untreated IOP and CCT(3) in mm (ultrasound pachymetry). PCI distribution in 220 normal controls, 53 patients with normal-tension glaucoma (NTG), 76 with ocular hypertension (OHT), and 89 with primary open-angle glaucoma (POAG) was investigated. PCI's ability to discriminate between glaucoma (NTG+POAG) and non-glaucoma (controls+OHT) was compared with that of three published formulae for correcting IOP for CCT. Receiver operating characteristic (ROC) curves were built. RESULTS: Mean PCI values were: Controls 92.0 (SD 24.8), NTG 129.1 (SD 25.8), OHT 134.0 (SD 26.5), POAG 173.6 (SD 40.9). To minimise IOP bias, eyes within the same 2 mm Hg range between 16 and 29 mm Hg (16-17, 18-19, etc) were separately compared: control and NTG eyes as well as OHT and POAG eyes differed significantly. PCI demonstrated a larger area under the ROC curve (AUC) and significantly higher sensitivity at fixed 80% and 90% specificities compared with each of the correction formulas; optimum PCI cut-off value 133.8. CONCLUSIONS: A PCI range of 120-140 is proposed as the upper limit of "normality", 120 being the cut-off value for eyes with untreated pressures
Resumo:
BACKGROUND: Noninvasive intraocular pressure (IOP) measurement in mice is critically important for understanding the pathophysiology of glaucoma. Rebound tonometry is one of the methods that can be used for obtaining such measurements. We evaluated the ability of the rebound tonometer (RT) to determine IOP differences among various mouse strains and whether differences in corneal thickness may affect IOP measurements in these animals. MATERIALS AND METHODS: Five different commonly used mouse strains (BALB/C, CBA/CAHN, AKR/J, CBA/J, and 129P3/J) were used. IOP was measured in eyes from 12 nonsedated animals (6 male and 6 female) from each strain at 2 to 3 months of age using the RT. IOPs were measured in all animals, on 2 different days between 10 AM and 12 PM. Subsequently, a number of eyes from each strain were cannulated to provide a calibration curve specific for that strain. Tonometer readings for all strains were converted to apparent IOP values using the calibration data obtained from the calibration curve of the respective strain. For comparison purposes, IOP values were also obtained using the C57BL/6 calibration data previously reported. IOP for the 5 strains, male and female animals, and the different occasion of measurement were compared using repeat measures analysis of variance. The central corneal thickness (CCT) of another group of 8 male animals from each of the 5 strains was also measured using an optical low coherence reflectometry (OLCR) pachymeter modified for use with mice. CCT values were correlated to mean IOPs of male animals and to the slopes and intercept of individual strain calibration curves. RESULTS: Noninvasive IOP measurements confirm that the BALB/C strain has lower and the CBA/CAHN has higher relative IOPs than other mouse strains while the AKR/J, the CBA/J, and the 129P3/J strains have intermediate IOPs. There is a very good correlation of apparent IOP values obtained by RT with previously reported true IOPs obtained by cannulation. There was a small but statistically significant difference in IOP between male and female animals in 2 strains (129P3/J and AKR/J) with female mice having higher relative IOPs. No correlation between CCT and IOP was detected. CCT did not correlate with any of the constants describing the calibration curves in the various strains. CONCLUSIONS: Noninvasive IOP measurement in mice using the RT can be used to help elucidate IOP phenotype, after prior calibration of the tonometer. CCT has no effect on mouse IOP measurements using the RT.
Resumo:
BACKGROUND: Ibopamine is an alpha-adrenergic agent and causes an elevation of intraocular pressure in eyes with increased outflow resistance. It has been proposed as a test substance for the detection of early ocular hydrodynamic disorders. PATIENTS AND METHODS: A total of 64 normal-tension glaucoma suspect eyes without anti-hypertensive treatment were enrolled. A daily pressure curve was registered with measurements at 7:00 am, 8:00 am, 12:00 am, 17:00 pm using an applanation tonometer and a contour tonometer followed by instillation of ibopamine 2% in both eyes. Tonometry was performed every 15 minutes during the following hour. An IOP increase of > 2.0 mmHg was considered positive. RESULTS: The positive test group showed a significant pressure increase from 18.04 to 22.06 mmHg. Ocular pulse amplitude increased from 2.96 to 3.97 mmHg and was positively correlated with the pressure. Intraocular pressure was unchanged in the negative test group. Central corneal thickness was not significantly different in the two groups (p = 0.32). CONCLUSIONS: Ibopamine 2% eye drops have a positive pressure effect in 50% of suspected normal-tension glaucoma eyes and may differentiate between eyes with normal trabecular outflow capacity and eyes with increased resistance in the trabecular meshwork that are prone to pressure peaks and deterioration to glaucoma.
Resumo:
Candida albicans is the most frequent cause of fungal keratitis in temperate regions. Caspofungin has potent activity against Candida spp. in a variety of clinical settings. Little is known, however, about its activity against fungal keratitis. We compared the efficacy of topical caspofungin with that of topical amphotericin B (AMB) in a rabbit model of experimental keratomycosis. Keratitis was induced with a standardized inoculum of Candida albicans (SC 5314) placed on the debrided cornea. Twenty-four hours after infection, animals were randomly assigned to treatment with 0.15% caspofungin, 0.5% caspofungin, 0.15% AMB, and a saline control (n = 12 rabbits in each group). For the first 12 h, treatment was repeated every 30 min and, after a 12-h pause, was resumed at hourly intervals for another 12 h. The animals were examined and killed 12 h after administration of the last dose. Treatment effects were evaluated by clinical assessment, fungal culture, and histopathology. Drug treatment significantly reduced corneal fungal recovery from 3.78 log10 CFU in saline-treated animals to 2.97, 1.76, and 1.18 log10 CFU in animals treated with 0.15% caspofungin, 0.5% caspofungin, and 0.15% AMB, respectively. By histopathology, the mean hyphal density was significantly lower in the corneas of treated animals than in those of the controls; there was no difference in hyphal densities between the different treatment groups. The depth of corneal invasion was not significantly reduced by the antifungal treatments. By clinical assessment, keratitis progressed in animals treated with saline, whereas disease progression was inhibited by all drug treatment regimens. In our rabbit model, 0.5% caspofungin was as effective as 0.15% AMB for the topical treatment of Candida keratitis. The potential clinical efficacy of caspofungin awaits further investigation.
Resumo:
Encephalitozoon cuniculi was documented to cause disseminated microsporidial infection including an iris tumor and endophthalmitis in an adolescent with idiopathic CD4+ T-lymphocytopenia. The diagnosis was established by microscopic, serologic and molecular methods. E. cuniculi (rabbit strain) was identified from the iris tumor, as well as from urine, conjunctival, corneal, and nasal swabs. Treatment with oral albendazole led to rapid improvement. This case raises the possibility of disseminated microsporidial infection in the context of idiopathic CD4+ T-lymphocytopenia and possibly advanced human immunodeficiency virus (HIV) infection, and above all the possibility of intraocular infection with E. cuniculi in humans.
Resumo:
PURPOSE: To compare the performance of dynamic contour tonometry (DCT) and Goldmann applanation tonometry (GAT) in measuring intraocular pressure in eyes with irregular corneas. METHODS: GAT and DCT measures were taken in 30 keratoconus and 29 postkeratoplasty eyes of 35 patients after pachymetry and corneal topography. Regression and correlation analyses were performed between both tonometry methods and between tonometry methods and corneal parameters. Bland-Altman plots were constructed. RESULTS: DCT values were significantly higher than GAT values in both study groups: +4.1 +/- 2.3 mm Hg (mean +/- SD) in keratoconus and +3.1 +/- 2.5 mm Hg after keratoplasty. In contrast to DCT, GAT values were significantly higher in postkeratoplasty eyes than in keratoconus. The correlation between the 2 tonometry methods was moderate in keratoconus (Kendall correlation coefficient, tau = 0.34) as well in postkeratoplasty eyes (tau = 0.66). The +/-1.96 SD span of the DCT-GAT differences showed a considerable range: -0.42 to +8.70 mm Hg in keratoconus and -1.87 to +7.98 mm Hg in postkeratoplasty eyes. In the keratoconus group, neither DCT nor GAT correlated significantly with any of the corneal parameters. In the postkeratoplasty group, both DCT and GAT measures showed a moderate positive correlation with corneal steepness, but only DCT had a significant negative correlation with the central corneal thickness (tau = -0.33). CONCLUSIONS: DCT measured significantly higher intraocular pressures than GAT in keratoconus and postkeratoplasty eyes. DCT and GAT measures varied considerably, and DCT was not less dependent on biomechanical properties of irregular corneas than GAT.
Resumo:
AIMS: To compare the outcome of prophylactic oral valacyclovir (VAL) or oral acyclovir treatment (ACV) in patients having undergone penetrating keratoplasty for herpetic keratitis (HK). METHODS: All patients having received a penetrating keratoplasty for HK and being treated postoperatively with either oral VAL or oral ACV (inclusion period from 12/97 to 3/06 and 5/92 to 9/96, respectively) were retrospectively evaluated. Records were analysed for postoperative reactivation of recurrent HK, graft rejection, endothelial cell loss, central corneal thickness and visual acuity after a follow-up of up to 5 years. RESULTS: Twenty patients received VAL and were compared with 19 patients being treated with ACV. Two patients developed clinical signs of recurrent herpetic disease in the VAL group compared with three patients in the ACV group. Two patients from both groups each developed an irreversible graft failure. Best corrected visual acuity improved in both treatment groups from baseline (logMAR) -1.97 (VAL), -1.47 (ACV) to -0.85, -0.72, respectively, at the 1-year follow-up and slightly deteriorated after 5 years in the ACV group (-0.71 VAL vs -1.14 ACV). CONCLUSION: Prophylactic oral VAL treatment is at least as effective as ACV in preventing recurrence in patients who underwent corneal transplantation for HK. The tolerability of the two drugs is similar, but the dosing for VAL might be more comfortable for patients.