Retinopatía diabética proliferativa ilustrada por reflectancia infrarroja / Proliferative diabetic retinopathy imaged by near-infrared reflectance

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Optical coherence tomographic angiography shows reduced deep capillary flow in paracentral acute middle maculopathy.

INTRODUCTION: Paracentral acute middle maculopathy (PAMM) has been described as an ischemic lesion of the middle retinal layers with a characteristic lamellar hyper-reflective placoid appearance in the acute phase and thinning of the involved retinal layers in the chronic phase. Optical coherence tomographic angiography (OCTA) is a novel and non-invasive technique for imaging retinal capillary vasculature with en face segmentation capabilities. METHOD: Case series. We describe two patients with PAMM who underwent clinical examination and multimodal imaging including OCTA. RESULTS: In the first patient, who presented with PAMM secondary to acute cilioretinal artery occlusion, OCTA demonstrated reduction in flow in the deep capillary plexus (DCP). One month later, OCTA revealed a flow void due to thinning of the GCL, INL, and OPL and paradoxical apparent ONL thickening. Similar findings of focal retinal lamellar ectopia were seen in the second patient, who had an incidentally detected chronic PAMM lesion. CONCLUSIONS: OCTA images the superficial and deep capillary plexi independently. PAMM is characterized by acute and chronic attenuation of the DCP flow signature. Focal lamellar ectopia in PAMM is discussed.

New Leptospira serovar Sokoine of serogroup Icterohaemorrhagiae from cattle in Tanzania.

The prevalence of leptospirosis is generally high in domestic animals and rodents in Tanzania. Identification of Leptospira isolates from cattle was carried out to establish prevalent Leptospira serovars. Serological typing was done based on monoclonal antibodies and the standard cross-agglutination absorption test. Molecular typing involved pathogenic- and saprophytic-specific PCRs and a PCR specifically amplifying DNA from the species Leptospira kirschneri. DNA fingerprinting with primers derived from sequences of insertion elements IS1500 and IS1533 was carried out. Both serological and molecular characterization indicated that one of the Leptospira isolates, coded RM1, represents a new serovar of the species L. kirschneri of serogroup Icterohaemorrhagiae. The serovar name Sokoine is proposed for this new Leptospira isolate.

Antibiotic resistance pattern and visual outcome in experimentally-induced Staphylococcus epidermidis endophthalmitis in a rabbit model.

OBJECTIVE: To study whether the clinical outcome of Staphylococcus epidermidis-induced endophthalmitis in rabbits is related to the antibiotic resistance pattern of the infecting strain. DESIGN: Experimental animal study. PARTICIPANTS: The right eyes of 36 New Zealand white albino rabbits were inoculated with strains of S. epidermidis that displayed various patterns of antibiotic resistance. METHODS: There were 12 rabbits in each of three study groups: fully antibiotic susceptible (FS), partially antibiotic resistant (PR), and multiresistant (MR). Five days after inoculation, the eyes were enucleated and prepared for histologic studies. MAIN OUTCOME MEASURES: Comparisons among the three groups were made based on electroretinographic (ERG) findings, histologic evaluation by a masked observer, and clinical examination. RESULTS: Electroretinographic findings on all rabbits were made by an unmasked observer. At 30 hours after inoculation, the ERG was diminished to 65% of normal for group FS, compared with a flat ERG waveform for groups PR (P < 0.05) and MR (P < 0.05). The ERG waveform was flat for all three groups at 72 hours after inoculation. Histologic evaluation by use of a histologic score revealed that the degree of inflammation and destruction of the retina was less for group FS (n = 10) compared with groups PR (n = 8) and MR (n = 8). Clinical examination revealed that there was a trend of less ocular inflammation for group FS compared with groups PR and MR. CONCLUSIONS: In a rabbit model of S. epidermidis-induced endophthalmitis, antibiotic-susceptible strains caused less inflammation and destruction of the infected retina than did antibiotic-resistant strains.

[Bacterial colonization of conjunctiva with Propionibacterium acnes before and after polyvidon iodine administration before intraocular interventions]. / Bakterielle Keimbesiedelung der Konjunktiva mit Propionibacterium acnes vor und nach Polyvidon-Jod-Applikation vor intraokulären Eingriffen.

BACKGROUND: Propionibacterium acnes has been described as a causative agent of postoperative endophthalmitis. This gram-positive, immotile, non-spore-forming bacterium is highly pleomorphic and grows under conditions of low to no oxygen concentration. It is commonly found on the skin at the openings of sebaceous glands and on hairs. A near-symptomless postoperative endophthalmitis occurs particularly when Propionibacteria are enclosed in the capsular bag. We investigated to what extent the number of P. acnes in the conjunctival sac can be reduced by preoperative disinfection with polyvidone iodine (1%). PATIENTS AND METHODS: A total of 261 patients with intrabulbar surgery had two conjuctival swabs taken: the first immediately prior to preoperative preparation in the operating theatre, following in-patient application of antibiotic eye drops (Polymyxin-B-sulfat, Neomycinsulfat and Gramicidin in combination); the second swab was taken after disinfection with polyvidone iodine before opening the conjunctiva. RESULTS: Of the 261 swabs, 60 (23%) taken prior to polyvidone iodine application were positive for Propinibacterium acnes. Following polyvidone iodine treatment, a further 5 (1.9%) remained culture-positive. After disinfection, 55 (92%) of the 60 positive swabs for Propionibacterium acnes remained culture-negative. CONCLUSIONS: We concluded that a significant reduction of P. acnes can be achieved by preoperative application of polyvidone iodine (1%) (P < 0.001).

Expression of crumbs confers apical character on plasma membrane domains of ectodermal epithelia of Drosophila.

The crumbs protein of Drosophila is an integral membrane protein, with 30 EGF-like and 4 laminin A G domain-like repeats in its extracellular segment, which is expressed on the apical plasma membrane of all ectodermally derived epithelia. Here, we present evidence to show that the insertion of crumbs into the plasma membrane is necessary and sufficient to confer apical character on a membrane domain. Overexpression of crumbs results in an enormous expansion of the apical plasma membrane and the concomitant reduction of the basolateral domain. This is followed by the redistribution of beta Heavy-spectrin, a component of the membrane cytoskeleton, and by the ectopic deposition of cuticle and other apical components into these areas. Strikingly, overexpression of the membrane-bound cytoplasmic portion of crumbs alone is sufficient to produce this dominant phenotype. Our results suggest that crumbs plays a key role in specifying the apical plasma membrane domain of ectodermal epithelial cells of Drosophila.