Selective thinning of the perifoveal inner retina as an early sign of hydroxychloroquine retinal toxicity

PURPOSE

To evaluate macular thickness profiles using spectral-domain optical coherence tomography (SDOCT) and image segmentation in patients with chronic exposure to hydroxychloroquine.

METHODS

This study included eight patients with chronic exposure to hydroxychloroquine (group 1) and eight controls (group 2). Group 1 patients had no clinically evident retinal toxicity. All subjects underwent SDOCT imaging of the macula. An image segmentation technique was used to measure thickness of six retinal layers at 200 microm intervals. A mixed-effects model was used for multivariate analysis.

RESULTS

By measuring total retinal thickness either at the central macular (2800 microm in diameter), the perifoveal region 1200-microm-width ring surrounding the central macula), or the overall macular area (5200 microm in diameter), there were no significant differences in the thickness between groups 1 and 2. On an image segmentation analysis, selective thinning of the inner plexiform+ganglion cell layers (P=0.021) was observed only in the perifoveal area of the patients in group 1 compared with that of group 2 by using the mixed-effects model analysis.

CONCLUSION

Our study results suggest that chronic exposure to hydroxychloroquine is associated with thinning of the perifoveal inner retinal layers, especially in the ganglion cell and inner plexiform layers, even in the absence of functional or structural clinical changes involving the photoreceptor or retinal pigment epithelial cell layers. This may be a contributing factor as the reason most patients who have early detectable signs of drug toxicity present with paracentral or pericentral scotomas.

Stent-assisted recanalisation of acute occlusive arteries in patients with acute limb ischaemia

OBJECTIVE

To assess the efficacy of stent-assisted recanalisation for acute limb ischaemia in patients considered unfit for thrombolysis or in patients with failed surgical recanalisation.

MATERIALS AND METHODS

Fifteen patients with acute limb ischaemia, treated with stent implantation, were analysed retrospectively. The reasons for acute limb ischaemia were a cardiogenic embolism (n=3), a traumatic injury (n=3), acute in situ thrombosis with atherosclerosis (n=6), immediate graft thrombosis (n=2), or a delayed thrombotic occlusion after a thrombin injection in the pseudoaneurysm (n=1). This study examined the technical and clinical outcomes of the procedures, including complications during the procedural and follow-up periods.

RESULTS

Stent-assisted recanalisation was technically successful and provided immediate recanalisation in all patients (15/15 patients, 100%) and reduced or eliminated the clinical symptoms in 12 patients (12/15 patients, 80%). Two patients died of multi-organ failure related to reperfusion injury, and one patient with a crash injury underwent a below-the-knee amputation as a result of wound necrosis despite recanalisation of the occluded bypass graft.

CONCLUSIONS

Stent-assisted recanalisation has a high technical success rate with good clinical results as a bailout procedure for the management of acute limb ischaemia in patients, considered unfit for thrombolysis or in patients with failed surgical recanalisation.

Perinatal survivin is essential for the establishment of pancreatic beta cell mass in mice

AIMS/HYPOTHESIS

Pancreatic beta cells undergo dynamic remodelling during the perinatal period, with enhanced neogenesis, proliferation and apoptosis observed. The molecular mechanisms responsible for these processes have yet to be elucidated. Survivin is an inhibitor of apoptosis, first described as being exclusively expressed in tumour and embryonic tissues with regulatory functions in mitosis and apoptosis. The aim of the present study was to define the essential physiological role of survivin in the pancreas.

METHODS

The expression profile of survivin was assessed in the mouse pancreas, and we generated a Pdx1 promoter-driven Survivin (also known as Birc5) knockout mouse using the Cre-loxP recombination system to determine the essential physiological function of survivin in the pancreas.

RESULTS

Survivin is transiently expressed in mouse pancreatic islets during the embryonic and neonatal periods. Targeted deletion of Survivin in the pancreas resulted in a significant decline in beta cell mass throughout the perinatal period, leading to glucose intolerance in the adult. Survivin-deficient islets showed decreased cell proliferation as a result of a delay in cell cycle progression with perturbations in cell cycle proteins. Survivin did not, however, play an essential role in beta cell apoptosis either during the physiological remodelling period or in response to streptozotocin. Islet development, islet architecture, microvasculature and apoptosis were not affected by the absence of survivin in the pancreas.

CONCLUSIONS/INTERPRETATION

Survivin expression in the pancreatic islets during the perinatal remodelling period is essential for the establishment of beta cell mass through cell cycle regulation.

Extensive spinal cord oedema and early syrinx formation due to tension pseudomeningocele after foramen magnum decompression

Pseudomeningoceles can cause syringomyelia. However, this is the first case report to show an unusually acute complication of a post-operative pseudomeningocele: spinal cord oedema and early syrinx, treated favourably with an early surgical intervention.

After facial nerve damage, regenerating axons become aberrant throughout the length of the nerve and not only at the site of the lesion: an experimental study

After facial nerve trauma, aberrant regeneration is associated with synkinesis. Animal models of mechanical nerve guides or reparative cell transplants at the site of a lesion have not been shown to improve disorganized regeneration. We examined whether this is because regenerating axons become disorganized throughout the length of the nerve and not only at the site of the lesion. In rats (n = 12), retrograde fluorescent tracer techniques were used to establish that most of the temporal branch fibres were carried in the superior half of the facial nerve trunk. In two further groups of rats (n = 24) a complete proximal facial nerve lesion was made, and the nerve immediately repaired by suture. After 4 weeks, at a second operation, the superior half of the facial nerve trunk was cut, either proximal or distal to the original lesion, and retrograde tracers were applied to distal branches of the nerve. It was possible to localize the points at which regenerating fibres became aberrant in their course by studying the number of labelled motoneurons in the facial nucleus after application of the tracer to the temporal branch of the nerve: this was similar in the distal and proximal hemisection groups, suggesting that aberrant axonal development occurred throughout the length of the nerve. Future strategies aimed at improving the organization of regeneration need to provide guidance cues not only at the site of the lesion as previously thought, but also throughout the length of the nerve.

Optical coherence tomography evaluation of zotarolimus-eluting stents at 9-month follow-up: comparison with sirolimus-eluting stents

OBJECTIVE

To evaluate the vascular response at 9 months after zotarolimus-eluting stent (ZES; Endeavor) implantation using optical coherence tomography (OCT). These findings were compared with those after implantation of a sirolimus-eluting stent (SES; Cypher Select).

DESIGN

Cross-sectional observational study with prospective OCT registry.

SETTING

Nine months after ZES or SES implantation.

PATIENTS AND METHODS

A total of 68 patients (32 ZES and 36 SES) underwent OCT at 9 months after stent implantation. The neointima hyperplasia (NIH) thickness inside each strut and percentage of NIH area at every 1 mm cross section were measured.

MAIN OUTCOME MEASUREMENT

The degree of neointimal coverage and the prevalence of malapposition at 9 months after ZES and SES implantation using OCT.

RESULTS

The mean (SD) NIH thickness (251.2 (110.0) mum vs 85.5 (53.3) mum, p<0.001) and percentage of NIH area (27.9 (9.1)% vs 11.2 (7.1)%, p<0.001) were significantly greater in ZES than in SES. The prevalence of uncovered strut as well as malapposed strut was significantly lower in ZES than in SES (0.3% vs 12.3%, p<0.001 and 0.08% vs 2.6%, p<0.001). Thrombus was not observed in ZES (0.0% in ZES vs 27.8% in SES, p = 0.001).

CONCLUSIONS

Neointimal coverage in ZES was almost complete and malapposition was very rare at 9-months' follow-up.

Rituximab for treatment of ocular inflammatory disease: a series of four cases

Rituximab may be effective in the treatment of ocular inflammatory disease. Dosing is less frequent than many medications currently available. Four cases are reported, each of which appeared to have responded well to treatment with rituximab, although patient 2 was able to remain on a low dose of prednisone for only 2 months. The ongoing pilot study will hopefully provide additional insight into the benefit of rituximab for treatment of scleritis and idiopathic orbital inflammatory disease.

p53, secreted by K-Ras-Snail pathway, is endocytosed by K-Ras-mutated cells; implication of target-specific drug delivery and early diagnostic marker

p53 is eliminated from K-Ras-mutated cancer cells through direct interaction with Snail. However, it is not achieved through proteasome-mediated degradation or transcriptional repression. Here we provide evidence that p53, binding with Snail, is exported from a K-Ras-mutated cell through a vesicle transport-like mechanism, independently using a p53-nuclear-exporting mechanism. Although we can detect p53 in culture media, a majority of p53 might be degraded by extracellular proteases. Thus, we can recover the secreted p53 in culture media by the inhibition of protease and endocytosis. In addition, a considerable amount of p53 is endocytosed by neighboring cells. As p53 resorption occurs in a K-Ras-dependent manner, treatment of recombinant p53 is detected in the whole-cell lysate of K-Ras-mutated cells, but not in that of wild-type cells. Using the property of p53, we can deliver the chemical (propidium iodine) into K-Ras mutated cells selectively. In contrast, Snail, a co-secreted protein with p53 in response to oncogenic K-Ras, shows resistance to endocytosis and protease, and results in remaining in the media. Thus, we can detect an autoantibody against Snail in the serum of a human cancer patient. Our finding can be used for a mutant K-Ras-specific anticancer drug delivery system and for the diagnosis of pancreatic, colon and lung cancers.