Nanogels designed for cell-free nucleic acid sequestration.

Chronic wounds exhibit over-expression of cell-free deoxyribonucleic acid (cfDNA), leading to a prolonged inflammation and non-healing wounds. Scavenging excessive cfDNA molecules is a promising strategy for chronic wound treatment. Nanoscopic particles act as efficient cfDNA scavengers due to their large surface area, however their efficiency in cfDNA uptake was limited by adsorption solely on the nanoparticle surface. In contrast, nanogels may provide multiple cfDNA binding sites in the nanoparticle interior, however their use for cfDNA scavenging is yet to be explored. Herein, we report cationic nanogels derived from a copolymer of chitosan and poly{2-[(acryloyloxy)ethyl]trimethylammonium chloride} end-grafted to the chitosan backbone as side chains. The nanogels retain their positive charge at the pH and ionic strength of chronic wound exudate, enabling electrostatically driven cfDNA scavenging. The network structure of the nanogels leads to the cfDNA sequestration in the nanogel interior, in addition to surface attachment. A key factor in cfDNA sequestration is the ratio of the pore size of the nanogel-to-cfDNA molecular dimensions. The enhanced cfDNA scavenging efficiency, along with biocompatibility of the nanogels, makes them a promising component of dressings for chronic wound treatment.

The balance between persistent virus infection and immune cells determines demyelination.

We addressed the contributions of persistent virus infection and immune cells to the pathogenesis of Theiler's virus-induced demyelination, a model for human multiple sclerosis. We developed a model involving the transfer of spleen cells into immunodeficient C.B-17-scid (SCID) mice, which normally die of overwhelming virus encephalitis without demyelination when infected with Theiler's virus. Adoptive transfer of nonimmune spleen cells from BALB/c mice into SCID mice resulted in the survival of all mice. However, these mice developed extensive demyelination and virus Ag/RNA persistence in the spinal cord white matter. The most demyelination was observed when mice received an intermediate number of spleen cells (1.8-7.5 x 10(6)), whereas too few cells (0.5 x 10(6)) did not ameliorate the SCID phenotype, and too many cells (30 x 10(6)) resulted in almost complete viral clearance with minimal demyelination. Adoptive transfer of spleen cells depleted of either CD4+ or CD8+ T cells produced vacuolar demyelination associated with virus persistence. In contrast, reconstitution with both CD4+ and CD8+ T cells produced less severe demyelination and partial clearance of virus. These experiments support the hypothesis that demyelination is the result of a balance between persistent virus infection and immune injury mediated by either CD4+ or CD8+ T cells.

Treatment and long-term follow up of a capillary angioma of the optic disc.

This case report describes the treatment of a capillary angioma involving the temporal aspect of the optic disc by photocoagulation therapy. It chronicles the effect of creating a retinal-choroidal adhesion at the temporal margin of the lesion in reducing exudation from the angioma spreading to involve the macula. The patient in question has been followed for sixteen years and vision in this eye has been maintained at 6/6 following the course of therapy described. Our experience suggests that direct laser treatment to capillary angiomas of the optic disc combined with photocoagulation barrier protection of the macula is beneficial and should be considered early when the lesion is relatively small.

Orbital infiltration by eyelid skin carcinoma.

This paper presents 5 patients seen in the Eye Clinic, Royal Victoria Hospital, Belfast with orbital infiltration of malignant eyelid tumours. The physical features and natural progression of the disease are described. The value of CT scans in determining the extent of the disease and patient management are described.

Failed retinal surgery caused by intraocular gas injection.

Four patients developed inferior retinal redetachment following initially successful surgery which included intraocular injection of air and sulphahexafluoride (SF6) mixture. In each case the intravitreal gas bubble produced vitreoretinal traction which opened inferior retinal breaks and led to retinal separation. Cautious use of intraocular gas is advised when bullous upper rhegmatogenous retinal detachments are accompanied by inferior retinal breaks.

Ocular larva migrans: a case report.

A case of intraocular toxocara larva migrans occurring in a 12-year-old boy is presented. Motility is inferred from the nature of multiple intraocular lesions observed. Possible mechanisms preventing a conclusive immunological response to the organism are discussed.

Ocular immobilization and its role in the management of superior retinal detachment.

Twenty-eight patients with bullous superior half retinal detachments were treated by pre-operative binocular occlusion, retrobulbar Bupivicaine hydrochloride and ocular immobilization using a temporary inferior rectus suture taped to the patient's forehead. Sufficient pre-operative flattening of the retina was achieved in each case to permit successful simple detachment surgery, with release of subretinal fluid in only three eyes. Eye movements were recorded by electro-oculography in five patients during separate periods of binocular occlusion, inferior rectus suture fixation and following a retrobulbar injection of 0.5 per cent Bupivicaine hydrochloride. All three methods of ocular immobilization caused a significant reduction in frequency and amplitude of eye movements compared with periods of unrestricted eye movement.

Management of superior-half-bullous retinal detachment.

We treated a selected group of patients with superior-half bullous retinal detachments by preoperative bed rest and immobilisation of the affected eye using a temporary inferior rectus suture taped to the brow. Sufficient flattening of the retina was achieved in each case to permit successful simple extrascleral detachment surgery.

Benign hemangioendothelioma of the lacrimal gland fossa.

A mass was surgically removed from a patient who complained of a swelling in the lacrimal gland fossa. Histopathologic evaluation of the mass showed an unusual variant of the benign capillary hemangioma that exhibited abundant endothelial cell proliferation, and that could alternatively be classified as a benign hemangioendothelioma.