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.

A rare case of vomiting: fourth ventricular B-cell lymphoma

We document the case of a 69-year-old man presenting with 6 weeks of intractable vomiting. Magnetic Resonance Imaging showed a homogenously enhancing mass in the caudal fourth ventricle. Surgical exploration and biopsy was performed and pathological examination demonstrated a high-grade B-cell lymphoma. The lesion was a primary tumour in an immuno-competent patient. Despite the increasing incidence of primary central nervous system lymphomas this is believed to be only the third ever case to have occurred at this rare site. We suggest that primary B-cell lymphoma should be considered with homogenous lesions of the fourth ventricle.

Comparison of inflammatory markers and angiographic outcomes after implantation of sirolimus and paclitaxel-eluting stents

OBJECTIVE

We compared the degree of systemic inflammation and its relation to the angiographic outcomes after drug-eluting stent (DES) implantations.

METHODS

We implanted a single DES in 79 stable angina patients (50 men; 60.4 (9.5) years of age; sirolimus-eluting stent (SES), n = 38; paclitaxel-eluting stent (PES), n = 41). The high-sensitivity C-reactive protein (hs-CRP) and interleukin 6 (IL-6) levels were determined before and at 24 hours, 72 hours, and 4 weeks after the percutaneous coronary intervention (PCI). An angiography and intravascular ultrasound (IVUS) were performed.

RESULTS

The hs-CRP and IL-6 levels at baseline did not differ between the two groups. The hs-CRP increased significantly from baseline at 24 hours and 72 hours after the PCI in both groups and there was a significant increase in the IL-6 level at 24 hours after the PCI in both groups. However, there was no significant difference between the two groups in any of the hs-CRP or IL-6 measurements. At follow-up, the late lumen loss was significantly higher in the PES group than in the SES group (0.57 (0.56) mm vs 0.28 (0.58) mm, respectively, p = 0.020). The neointimal hyperplasia (NIH) volume in the PES group was significantly higher than that in the SES group (23.1 (22.7) vs 3.8 (7.1) mm(3), respectively, p = 0.000). The percentage luminal volume reduction was higher in the PES group than in the SES group (18.9 vs 3.9%, p = 0.002). The absolute values or change in the inflammatory markers did not correlate with the NIH or stent volume reduction.

CONCLUSIONS

Our study showed that the benefits obtained from the SES, which reduce neointimal proliferation, are not probably mediated by the attenuation of the systemic inflammatory markers hs-CRP or IL-6.

Olfactory ensheathing cells in the nasal mucosa of the rat and human

Olfactory ensheathing cells are unique glial cells which have the ability to encourage nerve fibres to grow, and may have potential for use as a therapy for spinal cord and brachial plexus injuries. These images show olfactory ensheathing cells in the olfactory mucosa of the nose, and provide insight into their function. The olfactory mucosa is likely to be a convenient source for these cells in future clinical studies of CNS repair.

Adjacent segment disease after fusion for cervical spondylosis; myth or reality?

Cervical spondylosis is a common cause of radiculopathy and myelopathy, often treated by discectomy and interbody fusion. However, there has been a recent vogue for the use of artificial disc prostheses to decrease the risk of accelerated degenerative disease at adjacent levels. The short-term results of artificial disc replacements have been encouraging, but the long-term justification for using this new technology hinges on whether the incidence of adjacent segment disease decreases. It will also be necessary to demonstrate that movement at the operated levels is maintained and the incidence of device failure is low. We review the radiological, biomechanical and clinical evidence for adjacent segment disease, and the rationale for using artificial cervical disc replacements. There is presently insufficient evidence to justify the widespread use of artificial disc replacements in the treatment of cervical spondylosis, but neither is there sufficient evidence to criticize their use. Present evidence suggests that adjacent segment disease is partly due to the natural history of spondylotic disease and partly due to cervical fusion. Randomized trials are required to ascertain whether the incidence of adjacent segment disease changes with the use of artificial disc replacements in the long term. Indications for the use of artificial discs are presently unclear, but disc replacements might be recommended for 'young' patients who require an anterior cervical discectomy, with good ranges of neck movements, and an awareness of the satisfactory short-term results, but lack of long-term outcome data, preferably within the limits of a clinical trial.

Left ventricular diastolic functional reserve during exercise in patients with impaired myocardial relaxation at rest

BACKGROUND

Patients with similar grade diastolic dysfunction at rest may have a spectrum of alterations in diastolic function during exercise.

OBJECTIVE

To evaluate (a) whether exercise could unmask further diastolic abnormalities not evident during rest; (b) whether diastolic functional reserve during exercise is associated with exercise capacity.

METHODS

141 subjects (77 male, mean (SD) age 62 (9)) with abnormal left ventricular (LV) relaxation (mitral E/A <0.75) and/or deceleration time >240 ms, underwent graded supine bicycle exercise with simultaneous respiratory gas analysis and two-dimensional and Doppler echocardiographic study. Mitral inflow and annular velocities were measured at rest and during exercise. The LV diastolic function reserve index (DFRI) was calculated.

RESULTS

Patients were classified into two groups: group 1 (n = 64), DFRI <13.5; group 2 (n = 77), DFRI >or=13.5. The ratio of E/E' to stroke volume was used as an index of ventricular elastance (Ed). No significant differences between the groups in mitral inflow and annular velocities at rest were found. Mean (SD) Ed was not significantly different at rest between the groups (0.19 (0.07) vs 0.18 (0.06), p = 0.29). Ed was significantly higher during exercise in group 1 than in group 2 (25 W, 0.21 (0.09) vs 0.14 (0.04), p<0.001; 50 W, 0.22 (0.10) vs 0.15 (0.04), p<0.001). Group 1 subjects had a shorter exercise duration (8.2 (2.7) vs 9.4 (3.7) min, p = 0.04) and lower peak oxygen consumption (17.5 (4.5) vs 20.2 (5.4) ml/kg/min, p = 0.005).

CONCLUSIONS

Despite similar mitral flow and annular velocities at rest, different responses to exercise were seen in patients with abnormal LV relaxation at rest. Lower LV diastolic functional reserve was associated with higher ventricular elastance during exercise, and reduced exercise capacity.

Clinical studies in spinal cord injury: moving towards successful trials

Spinal cord injury is a devastating condition for which there is still no cure. Many new therapies have emerged in the past few decades that have attempted to improve the outcome after injury, with varying levels of supporting experimental and clinical data. Most studies have been preliminary and have lacked control groups, but positive results can often be embraced by clinicians and patients who are faced without an alternative, despite the poor design and bias of many studies. This article is a review of clinical studies in spinal cord injury and discusses guidelines for future clinical trial design.

Sandwich capture ELISA by a murine monoclonal antibody against a genus-specific LPS epitope for the detection of different common serotypes of salmonellas

A sandwich capture ELISA based on a murine monoclonal antibody against a genus-specific epitope in the outer core region of the Salmonella lipopolysaccharide is described for the detection of different common serotypes of salmonellas. Four h broth cultures of seven standard and 24 wild strains of salmonellas were all detected by the capture ELISA while overnight broth cultures of 21 non-salmonella standard strains were all negative. The capture ELISA detected 1 ng/ml of Ra lipopolysaccharide, 10(6)/ml of a smooth wild strain of Salm. typhimurium, and 1120 cells of Salm. heidelberg after enrichment culture for 4 h.

Determining the cost of tuberculosis case management in a low-incidence state

OBJECTIVE

To establish the average cost per patient of nurse case management for tuberculosis (TB) in Oregon State and so facilitate estimates of the overall cost of TB treatment. TB treatment is currently funded by a combination of local, state and federal public health dollars.

DESIGN

A longitudinal survey was used to assess the amount of case management time patients required per week. Additional patient information was collected from public health records. Mixed effects modeling techniques were used to identify important factors associated with case management time and to make predictions.

RESULTS

The following variables were significantly associated with case management time: non-adherence to treatment, the use of incentives, the phase of treatment and the presence of complicating factors, including human immunodeficiency virus infection, antibiotic resistance, homelessness and adverse reaction to drugs. The mean case management cost was $4831 per patient for a standard 28-week treatment course, and ranged from $3386 for a simple case to $7542 for a case with multiple complications.

CONCLUSIONS

These estimates are substantially higher than the current state funding for case management. Using these data, health officials can make better informed budget decisions and provide more appropriate support for TB control.

Systems biology of the neurospora biological clock

A major challenge of systems biology is explaining complex traits, such as the biological clock, in terms of the kinetics of macromolecules. The clock poses at least four challenges for systems biology: (i) identifying the genetic network to explain the clock mechanism quantitatively; (ii) specifying the clock's functional connection to a thousand or more genes and their products in the genome; (iii) explaining the clock's response to light and other environmental cues; and (iv) explaining how the clock's genetic network evolves. Here, the authors illustrate an approach to these problems by fitting an ensemble of genetic networks to microarray data derived from oligonucleotide arrays with approximately all 11 000 Neurospora crassa genes represented. A promising genetic network for the clock mechanism is identified.

Prohibitin interacts with RNF2 and regulates E2F1 function via dual pathways

Prohibitin, a tumor suppresser protein, plays an important role in the transcriptional regulation of various genes involved in cell-cycle control and proliferation. Recent studies have reported that the growth-suppressive property of the prohibitin protein is exhibited in its physical interaction with E2F family proteins and its subsequent repression of their transcriptional activity. Herein, we report that prohibitin interacts with RING finger protein 2 (RNF2), a member of the PcG (polycomb-group) family of proteins, and that the two proteins regulate the activity of E2F1 via dual pathways: the direct, prohibitin-mediated pathway and the indirect, p16-mediated pathway of E2F1 transcriptional regulation. Co-immunoprecipitation experiments showed that endogenous prohibitin interacts with endogenous RNF2. Interestingly, the expressed amounts of RNF2 and prohibitin were interdependently affected at the post-translational level. Furthermore, the depletion of either endogenous RNF2 or prohibitin using the RNA interference technique increased the level of p16 protein expression, resulting in a decrease in the transcriptional activity of E2F1 via the p16-CDK4-Rb pathway. In addition, chromatin immunoprecipitation assays showed that RNF2 was recruited to E2F1-response promoters along with prohibitin to inhibit the transcriptional activity of E2F1. Cell proliferation was also regulated by the prohibitin-RNF2 interaction. These results suggest that the RNF2-prohibitin complex regulates the activity of E2F1 via dual pathways.

Hepatic intra-arterial injection of 3-bromopyruvate in rabbit VX2 tumor

PURPOSE

To evaluate the antitumoral effects of an intra-arterial injection of 3-bromopyruvate (3-BrPA) on liver VX2 tumor in rabbits.

MATERIAL AND METHODS

Twenty rabbits with surgically implanted liver VX2 tumors were used. The rabbits were divided into three groups: a control, a saline, and a 3-BrPA group. Four rabbits were not treated at all, and they served as the control group. The saline group (n = 6) received only intra-arterial saline injection. The 3-BrPA group (n = 10) received an intra-arterial injection of 3-bromopyruvate through the hepatic artery. The delivered amounts of 3-bromopyruvate were as follows: 25 ml of 0.5 mM in six rabbits, 25 ml of 1.0 mM in two rabbits, and 25 ml of 2.0 mM in two rabbits. Four days after intra-arterial injection, the rabbits were sacrificed and histopathologic analysis of the explanted livers was performed with comparison of the tumor necrosis ratio (a percentage of the necrotic area versus the entire tumorous area) in each group.

RESULTS

The mean tumor necrosis ratio was 12.5+/-4.2%, 44.8+/-24.7%, and 49.4+/-14.3% in the control, saline, and 3-BrPA groups, respectively. Between the control and the saline group, and between the control and the 3-BrPA group the mean tumor necrosis ratio appeared to be significantly different (P<0.05). However, there was no statistical difference in the mean tumor necrosis ratio between the saline and the 3-BrPA group (P = 0.416).

CONCLUSION

A single session of intra-arterial injection of 3-BrPA showed no better results in terms of tumor necrosis than that of saline injection in a rabbit VX2 tumor model.

Transport of living cells with magnetically assembled nanowires

We present a technique of transporting and positioning living cells internalized by nickel (Ni) nanowires guided by magnetic field. Nanoscale magnetic nanowires are internalized by the Rat Neuroblastoma (ATCC number CRL-2754) and the cells are transported and positioned by magnetic fields from the magnetic material-coated electrodes. This technique may enable the interfacing between neurons and electronic devices to empower investigations pertaining to non-invasive neuron probing as well as nanofabricated neural pharmacological technologies.

Tissue factor serum levels and the risk of future coronary artery disease in apparently healthy men and women: the EPIC-Norfolk prospective population study

INTRODUCTION

Tissue factor (TF) has been implicated in coronary artery disease (CAD). High levels of circulating TF are found in patients with acute atherothrombotic events. Whether high serum TF levels predict risk of future CAD independent of known risk factors remains unknown.

METHODS

We conducted a prospective case-control study nested in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Norfolk population study. Cases (n=1037) were apparently healthy men and women, aged 45-79 years, who developed fatal or non-fatal CAD during follow-up. Controls (n=2005) were matched by age, sex, and enrolment time. Serum TF levels were measured using high-affinity antibodies.

RESULTS

In men, median TF levels were not significant higher in cases than in controls (59.0 pg mL-1, range: 16.7-370.4 vs. 54.9 pg mL-1, range: 16.2-452.4). In women, median TF levels were not significant higher in controls than in cases (73.4 pg mL-1, range: 16.7-492.3 vs. 50.5 pg mL-1, range: 16.5-376.7). The incidence of smoking was about double in the lowest compared with the highest TF quartile. Correcting for sex, age, body mass index, smoking, diabetes, systolic blood pressure, low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol and C-reactive protein levels, the risk of future CAD was 1.05 (95% CI: 0.81-1.36) for people in the highest TF quartile, compared with those in the lowest (P-value for linearity=0.8).

CONCLUSION

High levels of serum TF were not independently associated with an increased risk of future CAD in apparently healthy individuals.