Concurrent detection of other respiratory viruses in children shedding viable human respiratory syncytial virus.

Human respiratory syncytial virus (HRSV) is an important cause of respiratory disease. The majority of studies addressing the importance of virus co-infections to the HRSV-disease have been based on the detection of HRSV by RT-PCR, which may not distinguish current replication from prolonged shedding of remnant RNA from previous HRSV infections. To assess whether co-detections of other common respiratory viruses are associated with increased severity of HRSV illnesses from patients who were shedding viable-HRSV, nasopharyngeal aspirates from children younger than 5 years who sought medical care for respiratory infections in Ribeirão Preto (Brazil) were tested for HRSV by immunofluorescence, RT-PCR and virus isolation in cell culture. All samples with viable-HRSV were tested further by PCR for other respiratory viruses. HRSV-disease severity was assessed by a clinical score scale. A total of 266 samples from 247 children were collected and 111 (42%) were HRSV-positive. HRSV was isolated from 70 (63%), and 52 (74%) of them were positive for at least one additional virus. HRSV-positive diseases were more severe than HRSV-negative ones, but there was no difference in disease severity between patients with viable-HRSV and those HRSV-positives by RT-PCR. Co-detection of other viruses did not correlate with increased disease severity. HRSV isolation in cell culture does not seem to be superior to RT-PCR to distinguish infections associated with HRSV replication in studies of clinical impact of HRSV. A high rate of co-detection of other respiratory viruses was found in samples with viable-HRSV, but this was not associated with more severe HRSV infection.

Human bocavirus respiratory infections in children.

Human bocavirus (HBoV) was recently identified in respiratory samples from patients with acute respiratory infections and has been reported in different regions of the world. To the best of our knowledge, HBoV has never been reported in respiratory infections in Brazil. Nasopharyngeal aspirates were collected from patients aged <5 years hospitalized in 2005 with respiratory infections in Ribeirão Preto, southeast Brazil, and tested by polymerase chain reaction (PCR) for HBoV. HBoV-positive samples were further tested by PCR for human respiratory syncytial virus, human metapneumovirus, human coronaviruses 229E and OC43, human influenza viruses A and B, human parainfluenza viruses 1, 2 and 3, human rhinovirus and human adenovirus. HBoV was detected in 26/248 (10.5%) children of which 21 (81%) also tested positive for other respiratory viruses. Despite the high rates of co-infections, no significant differences were found between HBoV-positive patients with and without co-infections with regard to symptoms.

Prevention of prolapsed silicone stents in lacrimal intubation using an intrasac fixation suture.

Silicone stents are routinely used for the maintenance of patent mucosal passages in patients with nasolacrimal disorders. A common complication associated with the use of silicone stents is lateral migration or displacement of the tubes, which can be difficult to correct. This report describes a modified Quickert-Dryden approach with fixation of the tubes by an intrasac suture. From 1990 to 1996, 53 patients had silicone stents placed by this method with no complications related to tube displacement. The intrasac fixation suture has distinct advantages over other fixation methods.

Medpor Motility Coupling Post: a rabbit model.

PURPOSE: To verify if a Medpor porous polyethylene orbital implant (PPOI) (Porex Surgical, Atlanta, GA, U.S.A.), once vascularized, will tolerate a partially exposed titanium screw on its anterior surface. METHODS: Ten New Zealand white rabbits were enucleated and given Medpor PPOIs. Eight weeks postoperatively, Medpor Motility Coupling Posts (MCPs) (Porex Surgical) were placed into the orbital implants. Clinical tissue tolerance and histologic response to the new device were noted. RESULTS: The titanium screws were well tolerated by the animals. No case of post-operative infection, conjunctival inflammation, conjunctival erosion, MCP dislocation, or PPOI fragmentation was noted. A fibrous tissue growth over the titanium head was noted in all screws with a head height of 2.5 mm. The fibrous tissue overgrowth was not observed in screws with a head height of 4 mm or more. CONCLUSION: During the 6-month observation period, all implanted Medpor MCPs demonstrated favorable tissue tolerance and stable interfaces between the MCP and the conjunctiva and between the MCP and the PPOI.

Porous polyethylene sheet implant with a barrier surface: a rabbit study.

Soft tissue adhesion to the porous polyethylene sheet implant (PPSI) raises the concern of postoperative extraocular motility disturbance after orbital blowout fracture repairs using PPSI. A PPSI with a barrier surface (PPSI-B) has been developed to reduce adhesion between soft tissue and the implant. Six PPSI-B and six conventional PPSI were implanted under the scalps of three New Zealand white rabbits. The implants were harvested at 2-, 4-, and 20-week intervals. Clinical and histologic comparisons were made between PPSI-B and PPSI with regard to adhesion at the soft tissue-implant interface. Clinically, PPSI-B demonstrated less adhesion between soft tissue and implant compared with the conventional PPSI. Both types of implants demonstrated a complete fibrovascular ingrowth by 2 weeks. Because PPSI-B causes less adhesion at the soft tissue-implant interface, consideration should be given to the use of PPSI-B in repairs of orbital blowout fractures in which extraocular muscle is exposed to the implant surface.

Ptosis evaluation and management in the 21st century.

Determining the etiology and appropriate management of ptosis requires a directed evaluation seeking specific signs and symptoms. The clinical significance of such concomitant findings as motility deficits, pupillary abnormalities, levator function abnormalities, ocular manifestations, and associated systemic symptoms are discussed. Management options for correction of specific types of ptosis are reviewed. The clinical application of new technologies, such as the CO2 laser, or molecular biology, such as muscle cell transplantation or gene mapping, open exciting possibilities for future novel therapeutic alternatives. With an emphasis on newer and better, the fundamental question of indications and outcomes will remain relevant.

Hypoxic regulation of vascular endothelial growth factor in retinal cells.

BACKGROUND: Vascular endothelial growth factor (VEGF) is an angiogenic protein and vasopermeability factor whose intraocular concentrations are closely correlated with active neovascularization in patients with diabetes mellitus, central retinal vein occlusion, retinopathy of prematurity, and rubeosis iridis. OBJECTIVE: To determine whether hypoxia could induce expression of VEGF in retinal cells, which then promotes retinal endothelial cell proliferation. METHODS: Retinal pigment epithelial cells, pericytes, and microvascular endothelial cells were exposed to hypoxic conditions in vitro, and RNA expression of VEGF was evaluated by Northern blot analysis. The VEGF-specific proliferative potential of the medium was measured by means of retinal endothelial cell growth assays and VEGF-neutralizing VEGF receptor IgG chimeric protein. RESULTS: The VEGF RNA levels increased within 4 hours and reached elevations of threefold to 30-fold after 18 hours of hypoxia (0% to 5% oxygen, 5% carbon dioxide, 90% to 95% nitrogen) in all cell types (.01 < P < .03). Stimulation was dependent on oxygen concentration. The VEGF RNA levels were normalized by reinstitution of normoxia for 24 hours (P < .004). Medium conditioned by hypoxic retinal pericytes and retinal pigment epithelial cells stimulated retinal endothelial cell growth by 20% (P = .04), and this stimulation was entirely inhibited by VEGF-neutralizing receptor chimeric protein (P = .02). CONCLUSION: Hypoxia increases VEGF expression in retinal cells, which promotes retinal endothelial cell proliferation, suggesting that VEGF plays a major role in mediating intraocular neovascularization resulting from ischemic retinal diseases.

Vascular endothelial growth factor in ocular fluid of patients with diabetic retinopathy and other retinal disorders.

BACKGROUND: Retinal ischemia induces intraocular neovascularization, which often leads to glaucoma, vitreous hemorrhage, and retinal detachment, presumably by stimulating the release of angiogenic molecules. Vascular endothelial growth factor (VEGF) is an endothelial-cell-specific angiogenic factor whose production is increased by hypoxia. METHODS: We measured the concentration of VEGF in 210 specimens of ocular fluid obtained from 164 patients undergoing intraocular surgery, using both radioimmuno-assays and radioreceptor assays. Vitreous proliferative potential was measured with in vitro assays of the growth of retinal endothelial cells and with VEGF-neutralizing antibody. RESULTS: VEGF was detected in 69 of 136 ocular-fluid samples from patients with diabetic retinopathy, 29 of 38 samples from patients with neovascularization of the iris, and 3 of 4 samples from patients with ischemic occlusion of the central retinal vein, as compared with 2 of 31 samples from patients with no neovascular disorders (P < 0.001, P < 0.001, and P = 0.006, respectively). The mean (+/- SD) VEGF concentration in 70 samples of ocular fluid from patients with active proliferative diabetic retinopathy (3.6 +/- 6.3 ng per milliliter) was higher than that in 25 samples from patients with nonproliferative diabetic retinopathy (0.1 +/- 0.1 ng per milliliter, P = 0.008), 41 samples from patients with quiescent proliferative diabetic retinopathy (0.2 +/- 0.6 ng per milliliter, P < 0.001), or 31 samples from nondiabetic patients (0.1 +/- 0.2 ng per milliliter, P = 0.003). Concentrations of VEGF in vitreous fluid (8.8 +/- 9.9 ng per milliliter) were higher than those in aqueous fluid (5.6 +/- 8.6 ng per milliliter, P = 0.033) in all 10 pairs of samples obtained simultaneously from the same patient; VEGF concentrations in vitreous fluid declined after successful laser photocoagulation. VEGF stimulated the growth of retinal endothelial cells in vitro, as did vitreous fluid containing measurable VEGF. Stimulation was inhibited by VEGF-neutralizing antibodies. CONCLUSIONS: Our data suggest that VEGF plays a major part in mediating active intraocular neovascularization in patients with ischemic retinal diseases, such as diabetic retinopathy and retinal-vein occlusion.