Herpes simplex virus keratitis mimicking Acanthamoeba keratitis: a clinicopathological correlation

A 36-year-old male, soft contact lens wearer was referred by his primary ophthalmologist for corneal ulcer of the right eye (OD), which was persistent despite topical fluoroquinolone therapy for 1 month. A ring-shaped infiltrate typically seen in Acanthamoeba infection was noted, and topical therapy with chlorhexidine and polyhexamethylene biguanide was initiated. However, the patient's condition deteriorated over the next several weeks; thus, diagnostic and therapeutic penetrating keratoplasty was performed. The postoperative immunohistochemical analysis suggested a diagnosis of herpes simplex virus (HSV) keratitis. The patient ultimately improved after initiation of oral valacyclovir following penetrating keratoplasty. We report a case of a commonly encountered clinical entity, HSV keratitis, with an atypical clinical presentation, masquerading as Acanthamoeba keratitis.

Corneal abrasion following anaesthesia for non-ocular surgical procedures: A case-controlled study

The aim of this study was to identify risk factors associated with perioperative corneal abrasion at a single hospital in Mineola, New York (United States). A chart review was conducted of patients with perioperative corneal abrasion following non-ocular surgery and age-matched controls between June 2011 and November 2013. An age-stratified logistic regression model evaluated the association between corneal abrasion and potentially predisposing variables. The adjusted odds of a corneal abrasion occurring were 4.6 times greater for patients having surgery for ≥ 3 hours (p=0.001) and 3.6 times greater for patients with pre-existing ocular disease (p=0.02). Gender, diabetes status, surgical procedure or position were not found to be associated with the occurrence of a corneal abrasion. Corneal abrasions were associated with longer procedures and history of pre-existing ocular disease. No significant association between body positioning or surgical site and perioperative corneal abrasion was found. The study concludes that a longer duration of surgical procedure and pre-existing ocular disease are risk factors for perioperative corneal abrasion.

Effect of partial posterior vitreous detachment on retinal nerve fiber layer thickness as measured by optical coherence tomography

OBJECTIVE

To evaluate the effect of partially attached posterior vitreous detachments (pPVDs) at the optic disc on retinal nerve fiber layer (RNFL) thickness as measured by optical coherence tomography.

METHODS

A retrospective study was conducted using stored Stratus optical coherence tomography III scans of patients with suspected glaucoma from January 2003 to September 2006 at the Montefiore Medical Center, Bronx, New York. All scans were evaluated for vitreous attachments at the disc and were divided into control (without pPVD) and pPVD groups. The RNFL thickness was compared using the fast RNFL protocol. Patients were defined as glaucoma suspects based on clinical findings of either glaucomatous-appearing optic discs or elevated intraocular pressure. All study patients had normal Humphrey visual fields.

RESULTS

A total of 110 eyes from 110 patients were included; 59 were in the pPVD group and 51 were controls. Partial PVD was found in 40% of the glaucoma suspects. The mean RNFL thickness of eyes with pPVD was significantly broader than that of controls (101.6 microm vs 95.6 microm, respectively; P < .001). The average RNFL thickness of each quadrant was greater in the pPVD group than in the control group, with statistically significant differences in superior and inferior quadrants (P < .001 and P = .001, respectively).

CONCLUSIONS

More than one-third of this population of glaucoma suspects had a pPVD, indicating that this is a common phenomenon. The results suggest that RNFL thicknesses are greater in patients with pPVD than in controls. This may indicate a limitation of using RNFL thickness as a criterion for evaluating glaucomatous damage in patients with pPVD.

Nuclear translocation of insulin receptor substrate-1 by oncogenes and Igf-I. Effect on ribosomal RNA synthesis

The insulin receptor substrate-1 (IRS-1) is one of the major substrates of both the insulin and IGF-I receptors and is generally localized in the cytosol/membrane fraction of the cell. We show here that a substantial fraction of IRS-1 is translocated to the nucleus in mouse embryo fibroblasts (MEF) expressing the simian virus 40 T antigen. Nuclear translocation of IRS-1 occurs also in MEF stimulated with IGF-I or in MEF expressing the oncogene v-src. Nuclear translocation of IRS-1 can be demonstrated by confocal microscopy, immunohistochemistry, or subcellular fractionation. An antibody to IRS-1 immunoprecipitates from nuclear fractions (but not from cytosolic fractions) the upstream binding factor, which is a key regulator of RNA polymerase I activity and ribosomal RNA (rRNA) synthesis. In agreement with this finding, in 32D murine hemopoietic cells, nuclear translocation of IRS-1 correlates with a markedly increased rRNA synthesis. Our experiments suggest that nuclear IRS-1 may play a specialized role in rRNA synthesis and/or processing.

Simultaneous quantitation of fatty acids, sterols and bile acids in human stool by capillary gas-liquid chromatography

A simple method for the simultaneous gas-liquid chromatographic quantitation of fatty acids, sterols and bile acids from human fecal samples is described. The various compounds are directly converted into the n-butyl ester-trimethylsilyl ether derivatives, without prior isolation from the stool. Under these conditions, fecal bile acid derivatives are well resolved from each other and from those of fecal fatty acids and sterols without overlaps. The method was found to be reproducible and recoveries were similar to those obtained after exhaustive solvent extraction of fecal sterols, fatty acids and bile acids. Optimum derivatization conditions that allowed maximum recovery of fecal components with minimal destruction and application of the method for simultaneous bile acid, fatty acid and sterol analysis in human stool are described.

Highly simplified method for gas-liquid chromatographic quantitation of bile acids and sterols in human stool

A simple method for the gas-liquid chromatographic quantitation of human fecal bile acids and sterols is described where bile acids are subjected to n-butyl ester derivatization, without prior isolation from the stool, followed by trimethylsilylation of the sterols and bile acids. Under these conditions, bile acid derivatives are well resolved from each other and from the trimethylsilyl ether derivatives of fecal sterols and no overlap occurs. The method was shown to be highly reproducible and recoveries were similar to those obtained with other methods used for fecal bile acid analysis. Application of the method for bile acid and sterol analysis in human stool is described.