Subacute and acute fasciolosis in sheep in southern Brazil

Eight outbreaks of acute and subacute fasciolosis are reported in sheep in the municipality of Santa Vitória do Palmar, southern Brazil, in areas used for irrigated rice cultivation, which are subject to frequent flooding. Two outbreaks occurred mid-winter during July and August, and six occurred during spring and early summer. Morbidity ranged from 3 to 66.7 %, and mortality ranged from 3 to 50 %. Clinical signs included weight loss, mucosal pallor, apathy, depression, muscle tremors, and drooling; these were followed by death within approximately 24 h. Some sheep were found dead. Gross lesions were characterized by an irregular liver capsule with fibrin deposition and hemorrhages. The liver parenchyma contained hemorrhagic tracts or irregular clear areas alternated with dark hemorrhagic areas. Histologically, hemorrhagic dark red tracts of necrotic liver parenchyma and an inflammatory infiltrate were noted; these lesions coincided with the presence of immature flukes. Langhans-type giant cells, fibrous tissue, and bile duct cell proliferation were observed in subacute cases. Chronic fasciolosis is a well-known disease to farmers in southern Brazil; nevertheless, acute and subacute fasciolosis, which are more difficult to diagnose and treat, may cause important economic losses. Efficient control of fasciolosis requires integration of measures to treat infections in the definitive host, to reduce the population of snails of the genus Lymnaea, and to avoid contact between the parasite and host by appropriate pasture management.     

Amino acid immunoreactivity in normal human retina and after brachytherapy

We localised amino acids in the mid‐peripheral aged human retina and a retina that had undergone radiation treatment 10 years earlier. The distribution pattern of glutamate, γ‐amino butyric acid (GABA), glycine, glutamine and taurine, reflected patterns established in the primate retina. The retina that had undergone radiation exposure displayed both anatomical and neurochemical remodelling. The proximal retina comprised around 40 to 45 per cent of the total retina and neuronal kinesis and aberrant neuronal projections were also present. Amino acid neurochemistry was strikingly different with Müller cells displaying GABA loading, glycinergic neurons displaced and displaying a very high level of glycine labelling. We conclude that radiation exposure triggered these changes in the human retina and likely reflects general remodelling of structure and function following ischaemic damage to endothelial cells.     

Functional and anatomical remodeling in human retinal detachment

Rhegmatogenous retinal detachment is by far the most common indication for retinal surgery and a major cause of severe vision loss. Increased levels of glutamate found in the vitreous of human patients and persistent remodeling, even after reattachment, suggest substantial neurochemical, functional and anatomical changes have occurred in the detached retina. Therefore, this study was designed to characterize the morphological changes and glutamate receptor functionality in human rhegmatogenous retinal detachment. A cation channel permeating probe, agmatine (1-amino-4-guanidobutane; AGB), was employed to track endogenous and kainate (KA) driven channel functionality combined with immunocytochemical characterization of cellular remodeling. In the detached retina increased AGB permeability was identified in the outer retina while there was a decrease in the inner retina in basal conditions. KA receptors exhibited increased AGB permeability in ON bipolar cells and decreased permeability in calbindin labeled inner retinal cells. All retinal detachment samples demonstrated ectopic synaptic protein expression, photoreceptor processes extending toward the inner retina, and other remodeling features of retinal degeneration. These anatomical changes have been demonstrated in animal studies and are novel features unreported in primary cases of human retinal detachment. We conclude that deafferentation in retinal detachment leads to alteration of the glutamatergic pathway.     

Revisiting transconjunctival sutureless 25‐gauge vitrectomy: still worthwhile?

To present the outcomes of various retinal conditions treated with the sutureless 25-gauge (25G) vitrectomy technique. Retrospective case review of 232 eyes of 228 patients who underwent 25G vitrectomy from January 2003 to August 2006. Follow-up was a minimum of 3 months. Indications for surgery included idiopathic macular hole, rhegmatogenous retinal detachment, epiretinal membrane and proliferative diabetic retinopathy. Main outcome measures included final visual acuity, re-operation rate and surgical complications such as endophthalmitis, hypotony and retinal (re)detachment. For all cases, the mean overall visual acuity (logMAR) improved from 0.9 preoperatively to 0.5 ( P  < 0.0001). The improvement in acuity was highest in the rhegmatogenous detachment and diabetic groups. Transient postoperative hypotony was observed in 15 cases (9.2%) on day 1 after surgery but all these cases resolved. In 7.3% of the cases (17 out of 232) additional surgery was performed due to retina (re)detachment but final anatomic success was achieved in all cases; the detachments occurred within the first 3 months. One patients developed endophthalmitis (0.4%) which coincided with subconjunctival antibiotics being discontinued in favour of topical treatment. The 25G system remains a safe and effective technique for a variety of retinal conditions; significant fast visual rehabilitation is an advantage.