Automatic segmentation of anterior segment optical coherence tomography images

Optical coherence tomography (OCT) images can provide quantitative measurements of the eye's entire anterior segment. A new technique founded on a newly proposed level set-based shape prior segmentation model has been developed for automatic segmentation of the cornea's anterior and posterior boundaries. This technique comprises three major steps: removal of regions containing irrelevant structures and artifacts, estimation of the cornea's location using a thresholding technique, and application of the new level set-based shape prior segmentation model to improve segmentation. The performance of our technique is compared to previously developed methods for analysis of the cornea in 33 OCT images of normal eyes, whereby manual annotations are used as a reference standard. The new technique achieves much improved concordance than previous methods, with a mean Dice's similarity coefficient of > 0.92. This demonstrates the technique's potential to provide accurate and reliable measurements of the anterior segment geometry, which is important for many applications, including the construction of representative numerical simulations of the eye's mechanical behavior.

The influence of depression on physical complications in spinal cord injury: behavioral mechanisms and health-care implications

STUDY DESIGN

This study is a literature review and a proposed conceptual model.

OBJECTIVES

The objective of this study is to develop a conceptual model to explore the relationship between the presence of depressive symptoms and secondary physical complications such as pressure ulcers, urinary tract infections and autonomic dysreflexia in spinal cord injury (SCI).

SETTING

Community setting for individuals with SCI.

METHODS

A conceptual model explaining the mechanism underlying the relationship between depression and secondary physical SCI complications was developed based on the International Classification of Functioning, Disability and Health (ICF). A literature review was conducted to develop the model and to identify potential mechanisms responsible for the association.

RESULTS

A conceptual model based on ICF was created, informed by the literature discussing the link between depression and secondary physical SCI complications. Evidence in the literature was located that supports both a causal connection between depression and increased physical complications and/or the potential mechanisms mediating that connection.

CONCLUSION

The proposed model can be utilized to encourage further research on the influence of depression on SCI outcomes and the importance of prompt and effective identification and treatment of depressive symptoms. Additional research is needed to assess the relationship between depression and secondary physical SCI complications, and to test the validity of the model.

Stroke rehabilitation: recent advances and future therapies

Despite advances in the acute management of stroke, a large proportion of stroke patients are left with significant impairments. Over the coming decades the prevalence of stroke-related disability is expected to increase worldwide and this will impact greatly on families, healthcare systems and economies. Effective neuro-rehabilitation is a key factor in reducing disability after stroke. In this review, we discuss the effects of stroke, principles of stroke rehabilitative care and predictors of recovery. We also discuss novel therapies in stroke rehabilitation, including non-invasive brain stimulation, robotics and pharmacological augmentation. Many trials are currently underway, which, in time, may impact on future rehabilitative practice.

Prevalence of ketoacidosis at diagnosis of childhood onset Type 1 diabetes in Wales from 1991 to 2009 and effect of a publicity campaign

AIMS

To determine the proportion of cases of childhood Type 1 diabetes that present with ketoacidosis and any temporal trend. To assess the impact of a publicity campaign promoting earlier diagnosis.

METHODS

We used an all-Wales register of incident cases with data on 2046 children from 1991 to 2009. The proportion with ketoacidosis at diagnosis was compared with the Yorkshire Childhood Diabetes Register. On World Diabetes Day posters were sent to every pharmacy, school and general practitioner surgery across Wales and radio interviews given. A questionnaire survey was conducted in Gwent to assess penetrance of the campaign.

RESULTS

Annually, in 1991-2009 the proportion presenting with ketoacidosis varied between 20% and 33% (mean 25%) with no change over time. Similar proportions occurred in Yorkshire. Ketoacidosis was more common before age 5 years (37% of cases) than at age 5-9 years (20%) or 10-14 years (23%) (P < 0.001). From November 2006-2007 30% of cases presented with ketoacidosis and from November 2007-2008 25% cases presented with ketoacidosis. After the campaign (November 2008-2009) 26% presented with ketoacidosis (P = 0.72). The information had reached a low proportion of families. General practitioners referred immediately cases that presented to them.

CONCLUSIONS

Over 20 years in Wales there has been no change in the proportion of children with Type 1 diabetes initially presenting with ketoacidosis. This presentation occurs in a higher proportion of new cases aged under 5 years. Publicity to increase awareness did not reduce the proportion with ketoacidosis at diagnosis in Wales. We need to get the educational message through to parents to reduce ketoacidosis at presentation.

Safety results from a pooled analysis of randomized, controlled phase II and III clinical trials and interim data from an open-label extension trial of the interleukin-12/23 monoclonal antibody, briakinumab, in moderate to severe psoriasis

BACKGROUND

Anti-interleukin-12/23 treatment (anti-IL-12/23) has recently demonstrated significant efficacy for moderate to severe psoriasis, yet potential safety signals warrant further investigation.

OBJECTIVES

Expand safety findings for the anti-IL-12/23, briakinumab, beyond individual phase II and III clinical trials.

METHODS

Safety data pooled from five phase II and III clinical trials (parent studies) and an open-label extension study (OLE), through 22 October 2010; patients with ≥ 1 dose of briakinumab in a parent study or the OLE are included. All parent study briakinumab treatment groups were combined with the OLE population, which received 100-mg briakinumab every 4 weeks. Adverse events (AEs) were collected from the first dose of briakinumab, whether in a parent study or the OLE, through 45 days post-last dose.

RESULTS

Two thousand five hundred and twenty patients (4704 patient-years drug exposure) received ≥ 1 dose of briakinumab during the interim period: 5.6% withdrew due to AEs. Serious infections occurred in 1.3% and malignancies in 2.6% (including 1.0% basal cell carcinoma, 0.8% squamous cell carcinoma). Twenty-seven major adverse cardiovascular events (MACE) occurred, seven in one parent study and 20 in the OLE (incidence = 0.57 events/100 PY). Four cardiovascular risk factors were retrospectively found to be significant predictors for MACE during briakinumab exposure: history of cardiovascular disease, diabetes, body mass index (≥ 30) and baseline blood pressure (systolic ≥ 140 or diastolic ≥ 90).

CONCLUSIONS

Pooled briakinumab safety results from five parent studies and an OLE suggest increased rates of infections, malignancies and MACE, and that patients receiving anti-IL-12/23 treatment for moderate to severe psoriasis should be monitored for these potential safety signals.

Allergic Rhinitis and its Impact on Asthma (ARIA): achievements in 10 years and future needs

Allergic rhinitis (AR) and asthma represent global health problems for all age groups. Asthma and rhinitis frequently coexist in the same subjects. Allergic Rhinitis and its Impact on Asthma (ARIA) was initiated during a World Health Organization workshop in 1999 (published in 2001). ARIA has reclassified AR as mild/moderate-severe and intermittent/persistent. This classification closely reflects patients' needs and underlines the close relationship between rhinitis and asthma. Patients, clinicians, and other health care professionals are confronted with various treatment choices for the management of AR. This contributes to considerable variation in clinical practice, and worldwide, patients, clinicians, and other health care professionals are faced with uncertainty about the relative merits and downsides of the various treatment options. In its 2010 Revision, ARIA developed clinical practice guidelines for the management of AR and asthma comorbidities based on the Grading of Recommendation, Assessment, Development and Evaluation (GRADE) system. ARIA is disseminated and implemented in more than 50 countries of the world. Ten years after the publication of the ARIA World Health Organization workshop report, it is important to make a summary of its achievements and identify the still unmet clinical, research, and implementation needs to strengthen the 2011 European Union Priority on allergy and asthma in children.

Synthesis of protein-containing polymers in organic solvents

Subtilisin has been modified with polyethylene glycol (PEG) monomethacrylate (MW 8000) by reductive alkylation, and incorporated into polymethyl methacrylate durring free-radical initiated polymerization. The activity and stability of the PEG-modified enzymes have been determined in aqueous buffer and organic solvents. The K(m) and V(max) values for unmodified, singly and doubly modified subtilisin were compared in these environments, and the half-lives of both modified enzymes were remarkably high (up to 2 months). The protein-containing polymer was analyzed for activity and polymer properties, and our results indicate that active subtilisin can be incorporated into polymethyl methacrylate during polymerization in organic solvents while retaining its activity and stability. (c) 1995 John Wiley & Sons, Inc.

Microarray comparative genomic hybridization in prenatal diagnosis: a review

G-band chromosomal karyotyping of fetal cells obtained by invasive prenatal testing has been used since the 1960s to identify structural chromosomal anomalies. Prenatal testing is usually performed in response to parental request, increased risk of fetal chromosomal abnormality associated with advanced maternal age, a high-risk screening test and/or the presence of a congenital malformation identified by ultrasonography. The results of karyotyping may inform the long-term prognosis (e.g. aneuploidy being associated with a poor outcome or microscopic chromosomal anomalies predicting global neurodevelopmental morbidity). Relatively recent advances in microarray technology are now enabling high-resolution genome-wide evaluation for DNA copy number abnormalities (e.g. deletions or duplications). While such technological advances promise increased sensitivity and specificity they can also pose difficult challenges of interpretation and clinical management. This review aims to give interested clinicians without an extensive prior knowledge of microarray technology, an overview of its use in prenatal diagnosis, the literature to date, advantages, potential pitfalls and experience from our own tertiary center.

Inhalation toxicity of (1-->3)-beta-D glucan: recent advances

To investigate the effects of (1→3)-β-D-glucan after inhalation, animals were exposed to different forms of glucan and the number of lung lavage cells was determined 24 h after exposure. None of the different forms assayed caused any increase in cell numbers. In animals exposed to endotoxin, all types of cells were increased after 24 h. A simultaneous exposure to curdlan reduced this increase in a dose-related fashion. The results suggest that (1→3)-β-D-glucan-related acute injury to the lung is induced by mechanisms other than those induced by inflammagenic agents such as endotoxin.

Severe chronic allergic (and related) diseases: a uniform approach--a MeDALL--GA2LEN--ARIA position paper

Concepts of disease severity, activity, control and responsiveness to treatment are linked but different. Severity refers to the loss of function of the organs induced by the disease process or to the occurrence of severe acute exacerbations. Severity may vary over time and needs regular follow-up. Control is the degree to which therapy goals are currently met. These concepts have evolved over time for asthma in guidelines, task forces or consensus meetings. The aim of this paper is to generalize the approach of the uniform definition of severe asthma presented to WHO for chronic allergic and associated diseases (rhinitis, chronic rhinosinusitis, chronic urticaria and atopic dermatitis) in order to have a uniform definition of severity, control and risk, usable in most situations. It is based on the appropriate diagnosis, availability and accessibility of treatments, treatment responsiveness and associated factors such as comorbidities and risk factors. This uniform definition will allow a better definition of the phenotypes of severe allergic (and related) diseases for clinical practice, research (including epidemiology), public health purposes, education and the discovery of novel therapies.

Offspring number, pregnancy, and risk of a first clinical demyelinating event: the AusImmune Study

OBJECTIVE

To examine the association between past pregnancy, offspring number, and first clinical demyelination risk.

METHODS

Cases (n = 282) were aged 18-59 years with a first clinical diagnosis of CNS demyelination (first clinical demyelinating event [FCD]) and resident within 1 of 4 Australian centers (from latitudes 27° south to 43° south) from 2003 to 2006. Controls (n = 542) were matched to cases on age, sex, and study region, without first clinical diagnosis of CNS demyelination.

RESULTS

Higher offspring number was associated with FCD risk among women (p < 0.001) but not men (p = 0.71); difference in effect; p = 0.001. Among women, higher parity was associated with reduced risk of FCD (adjusted odds ratio 0.51 [95% confidence interval 0.36, 0.72] per birth) with a similar magnitude of effect observed among classic first demyelinating events (adjusted odds ratio 0.47 [95% confidence interval 0.29, 0.74]). The apparent beneficial effect of higher parity was also evident among parous women only (p < 0.001). Among cases, a clear female excess was evident for those with low but not high (4 or more) offspring number. Factors such as human leukocyte antigen DR15 genotype did not appear to modify the association between higher parity and a reduced FCD risk among women.

CONCLUSIONS

These findings are consistent with a cumulative beneficial effect of pregnancy. Temporal changes toward an older maternal age of parturition and reduced offspring number may partly underlie the increasing female excess among MS cases over time.

Negligence claims in UK total hip arthroplasty: a series of 167 consecutive cases

A review of negligence reports, detailing 227 complaints from the practices of two orthopedic surgeons, was undertaken. There were demonstrable differences in the number of complaints over leg-length discrepancy; femoral fracture and cup malposition when cemented versus uncemented implants were compared. Surgeons must appreciate the less forgiving nature of uncemented hip implants and the importance of preoperative planning particularly in the presence of abnormal anatomy.

Polysplenia syndrome with agenesis of the dorsal pancreas and preduodenal portal vein presenting with obstructive jaundice--a case report and literature review

Polysplenia, as part of the heterotaxy syndrome, is a rare embryological disorder which results from failure of development of the usual left-right asymmetry of organs. It is often associated with cardiac and biliary abnormalities, which are the usual causes of death in early neonatal life. A congenitally short pancreas and abnormalities with portal vein formation, gut malrotations and inferior vena cava anomalies are known to be associated with this rare syndrome. We report a case of polysplenia in an adult female presenting with obstructive jaundice owing to choledocholithiasis, possibly formed by biliary stasis as a result of compression of the common bile duct by the preduodenal portal vein, and review the literature. The patient was also found to have complete agenesis of the dorsal pancreas on CT and endoscopic retrograde cholangiopancreatography.

Saliva, Diagnostics, and Dentistry

Saliva, a scientific and clinical entity familiar to every oral health researcher and dental practitioner, has emerged as a translational and clinical commodity that has reached national visibility at the National Institutes of Health and the President’s Office of Science and Technology. “Detecting dozens of diseases in a sample of saliva” was issued by President Obama as one of the 14 Grand Challenges for biomedical research in the 21st Century ( National Economic Council, 2010 ). In addition, NIH’s 2011 Government Performance Report Act (GPRA) listed 10 initiatives in the high-risk long-term category ( Collins, 2011 ). The mandate is to determine the efficacy of using salivary diagnostics to monitor health and diagnose at least one systemic disease by 2013. The stage is set for the scientific community to capture these national and global opportunities to advance and substantiate the scientific foundation of salivary diagnostics to meet these goals. A specific calling is to the oral, dental, and craniofacial health community. Three areas will be highlighted in this paper: the concept of high-impact diagnostics, the role of dentists in diagnostics, and, finally, an infrastructure currently being developed in the United Kingdom—The UK Biobank—which will have an impact on the translational and clinical utilizations of saliva.

Stroke recurrence within the time window recommended for carotid endarterectomy

OBJECTIVE

In the North Dublin Population Stroke Study, we investigated the risk of recurrent stroke within the 14-day time window recommended for endarterectomy.

METHODS

In a population-based prospective cohort study, all ischemic stroke patients were identified over 1 year and categorized into those with (CS-positive) and without (CS-negative) ipsilateral carotid stenosis (CS) (≥50% lumen narrowing). Nonprocedural stroke recurrence was determined at 72 hours and 7 and 14 days.

RESULTS

Of 365 ischemic stroke patients with carotid imaging, 51 were excluded due to posterior circulation or nonlateralizing stroke, ipsilateral carotid occlusion, or intracranial stenosis, leaving 314 included for analysis (36 CS-positive and 278 CS-negative). Recurrent stroke occurred in 5.6% (2/36) CS-positive and 0.4% (1/278) CS-negative patients by 72 hours of symptom onset (p =0.003), 5.6% (2/36) CS-positive and 0.7% (2/278) CS-negative patients (p =0.01) by 7 days, and in 8.3% (3/36) CS-positive and 1.8% (5/278) CS-negative patients by 14 days (p =0.02). On multivariable Cox regression analysis, CS was the only independent predictor of recurrence at 72 hours (adjusted hazard ratio [HR] 36.1, 95% confidence interval [CI] 1.6-837.5, p =0.03), and 7 days (HR 9.1, 1.1-79.2, p =0.05), with a trend at 14 days (HR 4.6, 0.9-22.8, p =0.06).

CONCLUSIONS

Although only a minority of patients with symptomatic CS had a recurrent stroke within 14 days, early recurrent stroke risk was high, particularly within the first 72 hours. Earlier carotid revascularization or improved acute medical treatment may reduce recurrence in this high-risk group.

R, Pestka J, Williams D, Glenn A. The current state of mycotoxin biomarker development in humans and animals and the potential for application to plant systems

Filamentous fungi that contaminate livestock feeds and human food supply often produce toxigenic secondary metabolites known as mycotoxins. Among the hundreds of known mycotoxins, aflatoxins, deoxynivalenol, fumonisins, ochratoxin A and zearalenone are considered the most commercially important. Intense research on these mycotoxins, especially aflatoxin, has resulted in the development of 'biomarkers' used to link exposure to disease risk. In the case of aflatoxin this effort has led to the discovery of both exposure and mechanism-based biomarkers, which have proven essential for understanding aflatoxin's potential for causing disease in humans, including subtle effects on growth and immune response. Fumonisin biomarkers have also been used extensively in farm and laboratory animals to study the fumonisin-induced disruption of cellular and systemic physiology which leads to disease. This review summarises the status of mycotoxin biomarker development in humans and animals for the commercially important mycotoxins. Since the fungi responsible for the production of these mycotoxins are often endophytes that infect and colonise living plant tissues, accumulation of mycotoxins in the plant tissues may at times be associated with development of plant disease symptoms. The presence of mycotoxins, even in the absence of disease symptoms, may still have subtle biological effects on the physiology of plants. This review examines the question of whether or not the knowledge gained from mechanistic studies and development of biomarkers in animal and human systems is transferable to the study of mycotoxin effects on plant systems. Thus far, fumonisin has proven amenable to development of mechanism-based biomarkers to study maize seedling disease caused by the fumonisin producer, Fusarium verticillioides. Expanding our knowledge of mechanisms of toxicity and the overt and subtle effects on animal, human, and plant systems through the identification and validation of biomarkers will further our ability to monitor and limit the damage and economic impact of mycotoxins.