Cancer History Avoids the Increase of Senescence Markers in Peripheral Cells of Amnestic Mild Cognitive Impaired Patients

Epidemiological studies show that having a history of cancer protects from the development of Alzheimer's Disease (AD), and vice versa, AD protects from cancer. The mechanism of this mutual protection is unknown. We have reported that the peripheral blood mononuclear cells (PBMC) of amnestic cognitive impairment (aMCI) and Alzheimer's Disease (AD) patients have increased susceptibility to oxidative cell death compared to control subjects, and from the opposite standpoint a cancer history is associated with increased resistance to oxidative stress cell death in PBMCs, even in those subjects who have cancer history and aMCI (Ca + aMCI). Cellular senescence is a regulator of susceptibility to cell death and has been related to the pathophysiology of AD and cancer. Recently, we showed that cellular senescence markers can be tracked in PBMCs of aMCI patients, so we here investigated whether these senescence markers are dependent on having a history of cancer. Senescence-associated βeta-galactosidase (SA-β-Gal) activity, G0-G1 phase cell-cycle arrest, p16 and p53 were analyzed by flow cytometry; phosphorylated H2A histone family member X (γH2AX) by immunofluorescence; IL-6 and IL-8 mRNA by qPCR; and plasmatic levels by ELISA. Senescence markers that were elevated in PBMCs of aMCI patients, such as SA-β-Gal, Go-G1 arrested cells, IL-6 and IL-8 mRNA expression, and IL-8 plasmatic levels, were decreased in PBMCs of Ca + aMCI patients to levels similar to those of controls or of cancer survivors without cognitive impairment, suggesting that cancer in the past leaves a fingerprint that can be peripherally traceable in PBMC samples. These results support the hypothesis that the senescence process might be involved in the inverse association between cancer and AD.

Cancer History Is Associated with Slower Speed of Cognitive Decline in Patients with Amnestic Cognitive Impairment

Background: Several epidemiological studies report a negative association between Cancer and Alzheimer’s disease (AD). Objective: To characterize the trajectories of memory loss in individuals with early amnestic cognitive impairment with and without history of previous cancer. Methods: Cognitive deterioration was assessed using the Montreal Cognitive Assessment (MoCA) or MoCA-Memory Index Score (MoCA-MIS) biannually in subjects with early amnestic cognitive impairment followed-up retrospectively from 2007 to 2021. History of Cancer was obtained from clinical records. Simple linear regressions of MoCA-MIS scores were calculated for each subject and analyzed with K-means cluster analysis to identify subgroups with different cognitive decline trajectories. χ 2 and t tests were used for descriptive categorical and continuous variables and mixed multiple linear regressions to determine cognitive decline covariates. Results: Analysis of the trajectory of cognitive decline in 141 subjects with early amnestic cognitive impairment identified two subgroups: Fast (n = 60) and Slow (n = 81) progressors. At baseline Fast progressors had better MoCA-MIS (p <  0.001) and functionality (CDR p = 0.02, AD8 p = 0.05), took less anti-dementia medications (p = 0.005), and had higher depression rates (p = 0.02). Interestingly, Fast progressors slowed their speed of memory decline (from 1.6 to 1.1 MoCA-MIS points/year) and global cognitive decline (from 2.0 to 1.4 total MoCA points/year) when Cancer history was present. Conclusion: Two trajectories of amnestic cognitive decline were identified, possibly derived from different neurophysiopathologies or clinical stages. This study suggests that a history of previous Cancer slows down amnestic cognitive decline, specifically in a subgroup of subjects with depression at baseline and accelerated deterioration at follow-up.

Association of Vitamin D Receptor Polymorphisms with Amyloid-β Transporters Expression and Risk of Mild Cognitive Impairment in a Chilean Cohort

Background: Amyloid-β peptide (Aβ) deposition in Alzheimer’s disease (AD) is due to an imbalance in its production/clearance rate. Aβ is transported across the blood-brain barrier by LRP1 and P-gp as efflux transporters and RAGE as influx transporter. Vitamin D deficit and polymorphisms of the vitamin D receptor (VDR) gene are associated with high prevalence of mild cognitive impairment (MCI) and AD. Further, vitamin D promotes the expression of LRP1 and P-gp in AD-animal model brains. Objective: To associate VDR polymorphisms Apa I (rs7975232), Taq I (rs731236), and Fok I (rs2228570) with the risk of developing MCI in a Chilean population, and to evaluate the relationship of these polymorphisms to the expression of VDR and Aβ-transporters in peripheral blood mononuclear cells (PBMCs). Methods: VDR polymorphisms Apa I, Taq I, and Fok I were determined in 128 healthy controls (HC) and 66 MCI patients. mRNA levels of VDR and Aβ-transporters were evaluated in subgroups by qPCR. Results: Alleles A of Apa I and C of Taq I were associated with a lower risk of MCI. HC with the Apa I AA genotype had higher mRNA levels of P-gp and LRP1, while the expression of VDR and RAGE were higher in MCI patients and HC. For Fok I, the TC genotype was associated with lower expression levels of Aβ-transporters in both groups. Conclusion: We propose that the response to vitamin D treatment will depend on VDR polymorphisms, being more efficient in carriers of protective alleles of Apa I polymorphism.

What's new in atopic eczema? An analysis of systematic reviews published in 2019. Part 1: Risk factors and prevention

This review is part of an annual evidence update on atopic eczema (AE), providing a summary of key findings from 18 systematic reviews published in 2019 on AE risk factors and prevention. Parental atopy, particularly AE, is a risk factor for offspring AE, and this risk is augmented both by the number of parental atopic diseases present and the number of affected parents. Low-quality evidence suggests that autumn or winter birth increases childhood AE risk compared with birth in spring. There is some evidence to support filaggrin gene-environment interactions; however, this is limited by small underpowered studies. There is no evidence to suggest that polymorphisms in the -1082, -592 and -819 loci of the interleukin-10 gene increase susceptibility to AE. There is no robust evidence to support a relationship between childhood AE development and either yoghurt consumption in the first year of life, gut microbiota variants, prenatal or infantile paracetamol exposure, maternal antibiotic exposure or air pollution. Three systematic reviews investigated the effect of probiotics given during pregnancy or infancy; although low-quality evidence suggests benefits of combined probiotics, these studies were limited by significant heterogeneity. No relationship between the age at which complementary food and beverages are introduced and the risk of developing AE in infancy was identified. Consistent evidence showed no relationship between human milk feeding and infant AE development, aside from limited evidence suggesting a protective role in those with atopic heredity. This summary of recent evidence related to AE risk factors and prevention highlights the complex aetiology of AE.

What's new in atopic eczema? An analysis of systematic reviews published in 2019. Part 2: treatment

This review forms part of a series of annual evidence updates on atopic eczema (AE), and provides a summary of key findings from systematic reviews (SRs) published or indexed in 2019 related to AE treatment. Several SRs assessed the efficacy of topical corticosteroids (TCS), topical calcineurin inhibitors, topical phosphodiesterase-4 inhibitors and topical Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway inhibitors. However, there is a lack of good-quality trials comparing topical treatment agents with TCS, which remain the standard of care for patients with AE. Most of the included trials lack meaningful comparisons as they used vehicle as a comparator. There is also lack of harmonization of outcome measures for AE across studies. Large, well-designed RCTs are needed to further determine whether any specific emollients offer superior benefit. There is evidence highlighting limited benefit of oral H1 antihistamines as 'add-on' therapy to topical treatment of eczema. Mycophenolate mofetil may have a role in patients with refractory AE. Among biologic therapies, most of the efficacy data relate to dupilumab. Furthermore, there is growing evidence for the efficacy and safety of systemic JAK/STAT pathway inhibitors, but the existing data are of low quality.

Measurement properties of patient-reported outcome measures for eczema control: a systematic review

Atopic eczema (herein referred to as 'eczema') is a skin disease characterized by remitting and relapsing symptoms. The Harmonising Outcome Measures for Eczema (HOME) initiative was developed to establish a core outcome set (COS) for eczema to be measured for all future eczema trials. The core outcome set for atopic eczema clinical trials includes the domain for patient-reported eczema control, but a review of the validation of available eczema control instruments was lacking. We aimed to review the literature and systematically assess the measurement properties of validated patient-reported outcome instruments that capture eczema control. PubMed and Ovid EMBASE were searched up to 24 January 2020 for any study that reported on PROM instrument development or validation. The COnsensus-based Standards for the selection of health Measurement Instruments (COSMIN) criteria were used to assess the quality of eligible studies. We screened 12 036 titles and abstracts and 58 full texts. A total of 12 papers were included, reporting on seven PROMS. These were assessed with respect to development, reliability, construct validity and responsiveness. Two instruments, Recap of Atopic Eczema (RECAP) and the Atopic Dermatitis Control Tool (ADCT), have been developed and validated to a sufficient standard to support their recommendation as patient-reported outcome instruments for measuring control of atopic eczema as part of the HOME Core Outcome Set.

Scoping the international impact from four independent national dermatology trials

BACKGROUND

Research impact describes whether and how research results in wider benefits to society beyond academic publication. Little is known about translation of clinical trial research into dermatological practice.

AIM

We scoped international impact from four independently funded clinical trials published by our group over the past 10 years.

METHODS

This was a scoping survey of 35 international colleagues from 22 countries followed by a narrative summary of emergent themes.

RESULTS

All recipients kindly responded to the survey. At least 20 emergent themes were identified, which broadly included: (i) interest and enthusiasm in the concept of trying to document clinical trial impact; (ii) direct impacts such as adoption of the drug as tested and recommended from the trial results, including more confidence using the drug in slightly different ways for the same condition; (iii) the finding that trial impact was dependent on factors such as drug availability and country-specific disease patterns; and (iv) the educational value of good trial design for journal club discussions and improving future clinical trial designs in dermatology. Our survey suggests that uptake into clinical practice was surprisingly rapid and widespread.

CONCLUSION

Clinical trial research is of little use unless findings are translated into clinical practice for patient benefit. Our international scoping survey suggests that independent clinical trials that address important questions identified by the dermatology community have substantial, diverse and far-reaching impacts on dermatological practice.

Outcome assessment in dermatology clinical trials and cochrane reviews: call for a dermatology-specific outcome taxonomy

BACKGROUND

Standardized outcome reporting is crucial for trial evidence synthesis and translation of findings into clinical decision-making. The OMERACT 2.0 Filter and COMET outcome domain taxonomy propose frameworks for consistent reporting of outcomes. There is an absence of a uniform dermatology-specific reporting strategy that uses precise and consistent outcome definitions.

OBJECTIVES

Our aim was to map efficacy/effectiveness outcomes assessed in dermatological trials to the OMERACT 2.0 Filter as a starting point for developing an outcome taxonomy in dermatology.

METHODS

We critically appraised 10 Cochrane Skin Reviews randomly selected from all 69 Cochrane Skin Reviews published until 01/2015 and the 220 trials included covering a broad spectrum of dermatological conditions and interventions. Efficacy/effectiveness outcomes were mapped to core areas and domains according to the OMERACT 2.0 Filter. The extracted trial outcomes were used for critical appraisal of outcome reporting in dermatology trials and for the preliminary development of a dermatology-specific outcome taxonomy.

RESULTS

The allocation of 1086 extracted efficacy/effectiveness outcomes to the OMERACT 2.0 Filter resulted in a hierarchically structured dermatology-specific outcome classification. In 506 outcomes (47%), the outcome concept to be measured was insufficiently described, hindering meaningful evidence synthesis. Although the core areas assessed in different dermatology trials of the same condition overlap considerably, quantitative evidence synthesis usually failed due to imprecise outcome definitions, non-comparable outcome measurement instruments, metrics and reporting.

CONCLUSIONS

We present an efficacy/effectiveness outcome classification as a starting point for a dermatology-specific taxonomy to provide trialists and reviewers with the opportunity to better synthesize and compare evidence.

What's new in atopic eczema? An analysis of systematic reviews published in 2018. Part 1: prevention and topical therapies

This review is part of a series of annual updates that summarize the evidence base for atopic eczema (AE). The aim is to provide a succinct guide for clinicians on the key findings from 14 systematic reviews on the prevention and topical treatment of AE published or indexed in 2018. Various supplements, including long-chain polyunsaturated fatty acids, vitamin D and the probiotic Lactobacillus rhamnosus GG, given prenatally and postnatally, have not been shown to prevent AE in infants, although mixed strains of probiotics may decrease the risk of AE if given to the mother during pregnancy and to the infant for the first 6 months of life. In the postnatal period, there is no evidence that hydrolysed formula, compared with cow's milk formula (CMF), reduces the risk of AE in partially breastfed infants. However, weak evidence suggests that a specific partially hydrolysed whey formula decreases the risk of AE compared with CMF. No specific skin practices can be recommended to reduce the eczema risk in healthy term babies. There is weak evidence of a low risk of reversible hypothalamic-pituitary-adrenal axis suppression following 2-4 weeks of treatment with low-potency topical steroids, and conflicting evidence as to whether bleach bathing affects skin flora or AE severity. A single study demonstrated that the topical Janus kinase inhibitor tofacitinib at 2% significantly reduces the Eczema Area and Severity Index compared with vehicle. Topical naltrexone cream 1% improves pruritus (measured using a visual analogue scale) by 30% more than placebo. There is weak evidence that topical alternative therapies, including antioxidants, micronutrients and some herbal medicines, may improve AE.

Development and initial testing of a new instrument to measure the experience of eczema control in adults and children: Recap of atopic eczema (RECAP)

Background

Eczema control has been identified as an important outcome by key stakeholders in eczema research (including patients, carers, healthcare professionals and researchers) but no validated instruments for the domain have been identified.

Objectives

To develop a measurement instrument to capture a patient's perspective of eczema control that is suitable for use in eczema clinical trials.

Methods

Best practice for the development of a patient‐reported outcome was followed. A mixed‐methods approach was used to develop and refine a conceptual framework, generate, refine and select items and to test the distribution and construct validity of the final scale. The mixed‐methods approach involved expert panel meetings (including patient representatives, healthcare professionals and methodologists), and data collection using a focus group, cognitive interviews and an online survey with people with eczema and caregivers. Multivariable linear regression was used in the item selection process.

Results

Fourteen expert panel members co‐produced the instrument, with input from people with eczema and caregivers via a focus group (n = 6), cognitive interviews (n = 13) and an online survey (n = 330). The resulting instrument, Recap of atopic eczema (RECAP), is a seven‐item questionnaire that captures eczema control via self or caregiver report. The development process aimed to ensure good content validity and feasibility. Initial testing suggested no floor or ceiling effects and good construct validity. Hypothesized correlation with the Patient‐Oriented Eczema Measure was confirmed [r(258) = 0·83, P < 0·001].

Conclusions

RECAP has the potential to improve reporting of eczema control in research and clinical practice. Further exploration of measurement properties is required.

Linked Comment: Pattinson and Bundy. Br J Dermatol 2020; 183:418–419.

What's already known about this topic?

Eczema control has been identified as an important outcome by key stakeholders in eczema research (including patients, carers, healthcare professionals and researchers).

Qualitative studies suggest eczema control is a multifaceted and individual experience and no instrument has been identified that captures eczema control in this way.

What does this study add?

We have developed Recap of atopic eczema (RECAP), a seven‐item questionnaire to capture the experience of eczema control in all ages and eczema severities; there are two versions: a self‐reported version for adults and older children with eczema, and a caregiver‐reported version for younger children with eczema.

Designed with input from people with eczema, caregivers and healthcare professionals to ensure good content validity.

Initial testing of score distributions and construct validity suggests good measurement properties.

What are the clinical implications of the work?

The RECAP instrument is appropriate and feasible for measuring eczema control in clinical trials and may also be useful in routine practice.

Linked Comment: Pattinson and Bundy. Br J Dermatol 2020; 183:418–419.

Plain language summary available online

What's new in atopic eczema? An analysis of systematic reviews published in 2017. Part 1: treatment and prevention

This review forms part of a series of annual updates that summarize the evidence base for atopic eczema (AE). It provides a summary of key findings from 25 systematic reviews that were published or indexed during 2017, and focuses on the treatment and prevention of AE. There is high-quality evidence to demonstrate that dupilumab is better than placebo for the treatment of AE, is not associated with a higher incidence of adverse effects and does not increase the risk of infection compared with placebo; however, comparison studies with other systemic treatments are necessary. Topical tofacitinib is a promising treatment for mild-moderate AE, but currently lacks sufficient evidence from well-designed randomized controlled trials (RCTs) comparing with other active treatments. Topical doxepin may be effective for pruritus in AE, but available studies have short follow-up periods and longer-term outcomes are needed. Bleach baths were no more effective than water baths alone at reducing AE severity. Topical antibiotics cannot be recommended for infected AE, owing to insufficient evidence of benefit. There is little comparison of different emollients in RCTs, but overall evidence indicates that they reduce AE severity, are steroid-sparing and lead to better outcomes in combination with topical corticosteroids (TCS) than TCS alone. No clear benefit was demonstrated for vitamin D/C/E supplementation in pregnancy for eczema prevention.

Vitamin D Increases Aβ140 Plasma Levels and Protects Lymphocytes from Oxidative Death in Mild Cognitive Impairment Patients

BACKGROUND

Mild cognitive impairment (MCI) has an increased rate of progression to dementia. Alterations of some metabolic factors, such as deficiency of vitamin D, are a risk factor for cognitive deterioration. Vitamin D is involved in the clearance of β-amyloid (Aβ) from the brain. We have reported that lymphocytes from Alzheimer's disease (AD) patients have an increased susceptibility to oxidative death by H2O2 exposure, but currently it is unknown if this characteristic is modifiable in vivo.

OBJECTIVE

To determine if correction of low vitamin D levels protects lymphocytes from oxidative death and increases Aβ1-40 plasma levels in MCI and very early AD (VEAD) patients.

METHOD

Sixteen MCI, 11 VEAD and 25 healthy control (HC) voluntaries were evaluated with the Clinical Dementia Rating (CDR), Montreal Cognitive assessment (MoCA), and Memory Index score (MIS). Lymphocyte death was measured by flow cytometry after 20h exposure to H2O2. In patients with low levels of vitamin D -11 MCI, 9 VEAD and 20 HC- lymphocyte H2O2-death, plasma Aβ1-40 levels and cognitive status were evaluated pre- and post-vitamin D supplementation for 6 months.

RESULTS

Lymphocytes from MCI and VEAD patients showed increased susceptibility to oxidative death at study entry. In MCI, but not VEAD patients, lymphocyte susceptibility to death and Aβ1-40 levels plasma levels improved after 6 months of vitamin D supplementation. In addition, cognitive status on follow-up (18 months) improved in MCI patients after vitamin D supplementation.

CONCLUSION

Vitamin D supplementation may be beneficial in MCI. The lack of effect in VEAD may be due to a more advanced stage or different characteristics of the neurodegenerative process.

What's new in atopic eczema? An analysis of systematic reviews published in 2016. Part 3: nomenclature and outcome assessment

This review forms part of a series of annual updates that summarize the evidence base for atopic eczema (AE). It presents the key findings from 11 systematic reviews published in 2016 that focus on AE outcome assessment, disease impact and nomenclature. Systematic reviews on the treatment and prevention of AE are summarized in Part 1 of this update, and systematic reviews on the epidemiology of and risk factors for AE are summarized in Part 2. Six reviews summarized what outcome measurement instruments have been used in published AE trials, or summarized validation studies for the available instruments. These reviews were used to inform consensus decisions by the Harmonising Outcome Measures for Eczema initiative. Although validated instruments exist for clinical signs and patient-reported symptoms, there are currently no validated instruments for capturing quality of life or long-term control. Four reviews examined the impact of AE on children and their families, but few studies were included. One birth cohort study found no association between AE and educational attainment at 11 years. AE has a moderate impact on health-related quality of life and a substantial impact on family life. AE is a major risk factor for occupational hand dermatitis, and it is advised that young atopic individuals are informed about high-risk occupations. Further efforts are required to standardize the nomenclature for AE, which is also commonly known as 'atopic dermatitis' or 'eczema', and preferred terms vary around the world.

Report from the fifth international consensus meeting to harmonize core outcome measures for atopic eczema/dermatitis clinical trials (HOME initiative)

This is the report from the fifth meeting of the Harmonising Outcome Measures for Eczema initiative (HOME V). The meeting was held on 12-14 June 2017 in Nantes, France, with 81 participants. The main aims of the meeting were (i) to achieve consensus over the definition of the core domain of long-term control and how to measure it and (ii) to prioritize future areas of research for the measurement of the core domain of quality of life (QoL) in children. Moderated whole-group and small-group consensus discussions were informed by presentations of qualitative studies, systematic reviews and validation studies. Small-group allocations were performed a priori to ensure that each group included different stakeholders from a variety of geographical regions. Anonymous whole-group voting was carried out using handheld electronic voting pads according to predefined consensus rules. It was agreed by consensus that the long-term control domain should include signs, symptoms, quality of life and a patient global instrument. The group agreed that itch intensity should be measured when assessing long-term control of eczema in addition to the frequency of itch captured by the symptoms domain. There was no recommendation of an instrument for the core outcome domain of quality of life in children, but existing instruments were assessed for face validity and feasibility, and future work that will facilitate the recommendation of an instrument was agreed upon.

Cancer Imprints an Increased PARP-1 and p53-Dependent Resistance to Oxidative Stress on Lymphocytes of Patients That Later Develop Alzheimer's Disease

We have proposed that a common biological mechanism deregulated in opposite directions might explain the inverse epidemiological association observed between Alzheimer's disease (AD) and cancer. Accordingly, we showed that lymphocytes from AD patients have an increased susceptibility, whereas those from survivors of a skin cancer, an increased resistance to oxidative death induced by hydrogen peroxide (H₂O₂), compared to healthy controls (HC). We investigated the susceptibility to H₂O₂-induced death of lymphocytes in survivors of any type of cancer and in cancer survivors who later developed AD (Ca&AD). We also explored the involvement of Poly [ADP-ribose] polymerase-1 (PARP-1) and p53 pathways in the process, since both are involved in the increased susceptibility to death of AD lymphocytes. Lymphocytes from 11 cancer and 13 Ca&AD patients, and 12 HC were submitted to increasing concentrations of H₂O₂ for 20 h. Cell death was determined by flow cytometry, in the presence or absence of PARP-1 inhibition (3-aminobenzamide, 3-ABA), or p53 inhibition (pifithrin-α) or stabilization (Nut-3). PARP-1 and p53 mRNA levels were determined by Real-Time PCR. Lymphocytes from cancer and Ca&AD patients showed increased survival compared to HC, without differences between them, opposite to the increased susceptibility to death previously shown in AD. PARP-1 inhibition provided marked protection from H₂O₂-induced death in the two groups of patients, significantly greater than in HC. Pharmacological inhibition of p53 increased lymphocyte survival in Ca&AD patients, contrary to the effect previously reported in HC and AD. PARP-1 and p53 mRNA levels were elevated in Ca&AD lymphocytes compared with controls. In all, these results show that cancer imprints an increased resistance to H₂O₂-induced death in lymphocytes that persists after AD development, and is dependent on both PARP-1 and p53. p53 inhibition showed a differential role in cancer and Ca&AD compared to HC and AD lymphocytes, that could explain the inverse susceptibility to oxidative death in cancer and AD. These results are in agreement with the hypothesis of a common biological mechanism in AD and cancer. The similar cell death susceptibility and cell death pattern observed in cancer and Ca&AD lymphocytes suggests that cancer history leaves long term effects on lymphocyte cell death susceptibility.

What's new in atopic eczema? An analysis of systematic reviews published in 2015. Part 1: epidemiology and methodology

This review forms part of a series of annual updates that summarize the evidence base for atopic eczema (AE), providing a succinct guide for clinicians and patients. It provides a summary of key findings from 15 systematic reviews that were published during 2015, and focuses on the epidemiology and methodology issues of AE. For systematic reviews on the prevention and treatment of AE, see Part 2 of this update. The worldwide prevalence of AE during childhood has been calculated to be 7.89% (95% CI 7.88-7.89), based on studies of 1 430 329 children from 102 countries. Children with AE are four times more likely than controls to have allergic rhinitis and asthma [relative risk (RR) = 4.24, 95% CI 3.75-4.79]. Twin studies show the heritability of AE to be about 75%. AE is more prevalent in patients with vitiligo and alopecia, and is positively associated with a high body mass index in America and Asia but not in Europe. Possible relationships between AE and exercise, maternal folate supplementation, maternal stress and autism spectrum disorder (ASD) have been assessed, but more high-quality studies are needed for definitive conclusions. The Harmonising Outcomes Measures for Eczema (HOME) Initiative is developing a core set of outcome measures for AE trials. Suitable instruments for measuring quality of life are yet to be agreed, and use of Investigator Global Assessment in trials requires standardization. Transparent reporting of AE trials remains problematic.

PARP-1 and p53 Regulate the Increased Susceptibility to Oxidative Death of Lymphocytes from MCI and AD Patients

Mild cognitive impairment (MCI) is a clinically detectable initial stage of cognitive deterioration with a high conversion rate to dementia. There is increasing evidence that some of the cerebral alterations present in Alzheimer type dementia can be found in peripheral tissues. We have previously shown that lymphocytes from Alzheimer’s disease (AD) patients have increased susceptibility to hydrogen peroxide (H₂O₂)-induced death that depends on dementia severity. We here investigated whether lymphocytes from MCI patients show increased vulnerability to death, and explored the involvement of Poly [ADP-ribose] polymerase (PARP-1) and p53 in the regulation of this process. Lymphocytes from 16 MCI and 10 AD patients, and 15 healthy controls (HCs) were submitted to increasing concentrations of H₂O₂ for 20 h. Cell death was determined by flow cytometry, in the presence or absence of PARP-1 inhibitors (3-aminobenzamide (3-ABA) or Nicotinamide (NAM)), or the p53 inhibitor (nutlin-3) or stabilizer (pifithrin-α). PARP-1 and p53 mRNA levels were determined by quantitative PCR (qPCR). Lymphocytes from MCI patients showed increased susceptibility to death, attaining intermediate values between AD and controls. PARP inhibitors -3-ABA and NAM- markedly protected from H₂O₂-induced death, making the difference between MCI and controls disappear, but not the difference between AD and controls. PARP-1 mRNA expression was increased in MCI lymphocytes. Modulation of p53 with Nutlin-3 or pifithrin-α did not modify the H₂O₂-induced death of lymphocytes from MCI or AD patients, but augmented the death in control lymphocytes attaining levels similar to MCI and AD. Accordingly, p53 mRNA expression was increased in AD and MCI lymphocytes compared to controls. In all, these results show that increased oxidative death is present in lymphocytes at the MCI stage. PARP-1 has a preponderant role, with complete death protection achieved with PARP inhibition in MCI lymphocytes, but not in AD, suggesting that PARP-1 might have a protective role. In addition, deregulations of the p53 pathway seem to contribute to the H₂O₂-induced death in MCI and AD lymphocytes, which show increased p53 expression. The results showing a prominent protective role of PARP inhibitors opens the door to study the use of these agents to prevent oxidative death in MCI patients.

Reporting of symptoms in randomized controlled trials of atopic eczema treatments: a systematic review

'Symptoms' is a core outcome domain for atopic eczema (AE) trials, agreed by consensus as part of the Harmonising Outcome Measures for Eczema (HOME) initiative. To standardize and validate the core domain symptoms and symptom instruments for AE trials the HOME roadmap is followed. Its first step is to establish if and how symptoms have been measured in published AE treatment trials. Therefore the Global Resource for Eczema Trials database was used to collect all randomized controlled trials (RCTs) of treatments for AE between January 2000 and April 2014. Study selection and data extraction were performed by three reviewers independently. We identified the use of symptoms in 295 of 378 trials (78%). Symptoms as a primary end point were applied by 147 RCTs (50%). Seventeen different symptoms were measured, but mostly itch and sleep loss. Symptoms were assessed by only 37% of trials by a stand-alone symptom measurement. Overall 63% of RCTs used a composite instrument, and 30 different instruments were identified. The Scoring Atopic Dermatitis (SCORAD) index was the most commonly applied, but only 23% of RCTs reported the SCORAD symptom score separately. This systematic review demonstrates that symptoms, most frequently itch and sleep loss, are commonly reported in AE treatment trials, but are measured using many different instruments. Often symptoms are evaluated as part of a composite instrument, and currently it is not possible to extract symptoms-only data from most published studies. Future trials should report symptom scores to permit meta-analysis of the core outcomes.

'Toy' laser macular burns in children

PURPOSE

Laser 'toys' can be purchased online and imported with relative ease; the variety of such devices is a potential public safety concern. We describe five children with maculopathy following exposure to laser 'toys'.

METHODS

Case series of maculopathy following exposure to laser 'toys'.

RESULTS

Five children were seen in our Ophthalmic Unit with macular injuries following exposure to laser 'toys'. Clinically, three children had an acute vitelliform-like maculopathy which resolved to leave sub-foveal retinal pigment epithelium changes with reduced vision. One case was complicated by a choroidal neovascular membrane.

CONCLUSION

Laser 'toys', which resemble laser pointers, are increasingly available over the internet. Such 'toys' may not meet safety standards. Retinal injury in childhood following exposure to laser 'toys' is a public safety concern.

Childhood blindness in Uzbekistan

PURPOSE

To elucidate the aetiology of childhood blindness in the Republic of Uzbekistan and to assess the needs for future provision of ophthalmic services for children.

METHODS

Six hundred and seventy-one children in seven schools for the blind and visually impaired throughout Uzbekistan were examined using the WHO/PBL (World Health Organization Prevention Of Blindness) childhood blindness proforma. The locations were chosen to give a representation of the major areas of population within the country.

RESULTS

Of the 671 children examined, 506 (75.4%) were blind or severely visually impaired (corrected visual acuity of less than 6/60 (20/200) in the better eye). Cataract-related blindness (35%), retinal dystrophies (24%) and microphthalmos (23%) formed the three largest diagnostic categories.

CONCLUSIONS

The commonest avoidable cause of blindness was found to be cataract; the cause of poor vision may be due to unoperated cataract, aphakia, amblyopia or post-operative capsular fibrosis. The high proportion of retinal dystrophies may be related to the common practice of consanguineous marriage. The frequent finding of microphthalmos is discussed and compared with findings from other surveys. Glaucoma accounted for approximately 5% of the avoidable blindness.

Acoustic neuroma and the eye

A retrospective survey is presented of the case records of 138 patients who had undergone operative treatment for acoustic neuroma. The nature and incidence of ophthalmic features prior to and following surgery is documented. The study covers 12 years in two regional neurosurgical centres, under the care of six different neurosurgeons, one otolaryngologist and nine ophthalmologists. Of the 138 records examined, 61 patients (44%) required lid surgery of one variety or another. 18 (13%) developed minor superficial exposure keratopathy, 13 (9%) developed corneal opacification or clouding, two had recurrent infective abscesses and four developed optic atrophy. The development of corneal complications strongly correlates with the presence of documented preoperative fifth nerve involvement. Postoperative oculomotor cranial nerve palsies were seen in 10 patients (7%). Ophthalmologists should be involved in the perioperative management of these patients and certainly before irreversible corneal damage has occurred.

Aggressive management of an epidemic of chronic pseudophakic endophthalmitis: results and literature survey

Six cases of chronic endophthalmitis following extracapsular cataract extraction and lens implantation are reviewed. All were referred for tertiary management by one surgeon over a period of just over 2 years. In two of the cases coagulase negative staphylococci were isolated and in three Propionibacterium spp were retrieved. In the remaining case a mixed growth of coagulase negative staphylococci and Propionibacterium acnes was cultured. The surgical management, microbiological results, and eventual visual outcome are discussed. To our knowledge, this is the first documented outbreak of chronic pseudophakic endophthalmitis with commensal organisms from a single centre.

Development of atypical amiodarone keratopathy in a corneal graft

The presence of fine epithelial deposits in a whorled pattern (cornea verticillata) as a consequence of treatment with amiodarone is well documented. We present a case of amiodarone keratopathy in a grafted cornea which is atypical in that the orientation of the pattern is rotated through nearly 90 degrees to that normally observed. This observation runs counter to the hypothesis that cornea verticillata is a manifestation of the line of lid closure. We speculate on the mechanism directing the migrational pathways of epithelial cells.

On the energetics of conformational changes and pH dependent redox behaviour of electron transfer proteins

Calculations of the electrostatic interaction energies for four metalloproteins that carry out electron transfer are reported. Each protein has a pH dependent redox potential from which the measured electrostatic interaction energy is obtained. The calculations were made using the X-ray structure coordinates and a semimacroscopic model of the interactions. For cytochrome c-551 and HIPIP the calculated and observed interaction energies were found to be approximately the same, in agreement with the fact that significant conformational changes do not accompany the ionisations. For cytochrome c2 and azurin, however, major differences were found between the calculated and observed values. These are accounted for primarily by the occurrence of significant conformational changes accompanying the ionisations. The reorganisation energies for these conformational changes are approximately 7.0 and approximately 11.1 kJ.mol-1, respectively.

Factors influencing redox potentials of electron transfer proteins

The redox potentials of electron transfer proteins vary over a wide range, even when the type of redox center is the same. Rees [Proc. Natl. Acad. Sci. USA (1985) 82, 3082-3085] proposed that this variation of redox potential partly reflects the different net charges of the proteins, and he presented a linear correlation between these two properties for 36 proteins. A review of the factors that influence protein redox potentials makes it clear that this linear correlation is fortuitous. The key factors influencing redox potentials are the contributions to the Gibbs energy difference between the two redox states, resulting from bonding interactions at the redox center, electrostatic interactions between the redox-center charge and polar groups within the protein and solvent, and redox-state conformational changes. The relative importance of these terms is likely to vary from protein to protein.

Electrostatic interactions in globular proteins: calculation of the pH dependence of the redox potential of cytochrome c551

An equal mixture of oxidized and reduced cytochrome c551 experiences a change in the potential of the haem iron when one of the propionates attached to the haem is ionized. The change is 65 mV, which corresponds to an effective dielectric between the propionate and the iron of 27. It has been possible to use the algorithm of Warwicker & Watson (1982) to calculate the change in the potential at the haem iron arising from the change in ionization of the propionate. This gives the extra work required to oxidize or reduce the iron. The change in potential that we calculate is 90 mV, which corresponds to an effective dielectric of 19.5, between the propionate and the iron. In comparison with other commonly used dielectric models the agreement is very good.

The influence of electrostatic interactions between buried charges on the properties of membrane proteins

The importance of electrostatic interactions between buried charges in determining the properties of membrane proteins is considered. It is demonstrated that in some cases altered properties may result from the extraction of a membrane protein into an aqueous medium even when the protein conformation is unperturbed.

Electrostatic interactions in globular proteins. Different dielectric models applied to the packing of alpha-helices

The alpha-helix has an electric dipole arising from the alignment of peptide dipoles parallel to the helix axis. The effect of this alpha-helix dipole in the stabilization of the tertiary structure of globular proteins is examined using three of the commonly used dielectric models. These models are; (1) the uniform dielectric model, (2) the distance dependent dielectric model and (3) the cavity dielectric model. Of these the cavity model is the most reasonable since it attempts to describe the markedly different dielectric responses of the solvent and the protein. The protein is set at a low continuous dielectric value and the solvent is set at a high continuous dielectric value. It is found that for the cavity model of the dielectric the calculated interaction energy between two helices is strongly dependent upon how exposed the helix termini are to solvent. For helices with exposed termini the calculations using the cavity model yield electrostatic interaction energies which are lower by an order of magnitude than those obtained using the uniform dielectric model.