Expression of calcitonin gene-related peptide in atopic dermatitis and correlation with distress.

BACKGROUND: Atopic dermatitis (AD) is a chronic, inflammatory, often severely itching skin disorder. It may worsen due to stress, depression, or anxiety. Calcitonin gene-related peptide (CGRP) may be involved in inflammation signaling. CGRP has also been suggested in relation to stress, depression, and anxiety. This study aimed to investigate the expression of CGRP in the skin of patients with AD. METHODS: Twenty-seven adult patients with AD, characterized with clinical and psychodemographic parameters, were investigated regarding CGRP expression in skin biopsies, using an immunohistochemical technique. RESULTS: The total number of CGRP-positive nerve-like fibers was found to be higher in lesional skin than in non-lesional skin. Moreover, more inflammatory cells of dendritic shape intruded into the epidermis in lesional skin compared to non-lesional skin. Keratinocytes showing expression of CGRP were also found in lesional skin. Interestingly, the number of CGRP-positive nerve-like fibers in lesional skin correlated with depressive and anxiety scores. Correlation with depressive score was also found for round CGRP-positive inflammatory cells in the epidermis. CONCLUSIONS: CGRP may have a role in both the inflammatory process and distress, in AD.

Technique for Sutured Scleral Fixation of One-Piece Hydrophobic Acrylic Intraocular Lenses Dislocated Into the Vitreous.

PURPOSE: To present a suturing technique for safe refixation of posteriorly dislocated one-piece hydrophobic acrylic intraocular lenses (IOLs). METHOD: Retrospective data analysis of a series of 12 cases operated with vitrectomy, followed by IOL relocation to the retropupillary area, after which polypropylene sutures are passed through the optic-haptic junctions of the dislocated IOL and subsequently secured to the sclera. RESULTS: In all cases, the IOL remained centered throughout the follow-up period (mean 10.5 months, range 3 weeks-36 months). One case was complicated by vitreous hemorrhage the first postoperative day and later cystoid macular edema. Visual acuity was not compromised at the end of follow-up. CONCLUSION: The presented technique is safe and provides long-term stable refixation in cases of late posterior dislocation of a one-piece hydrophobic acrylic IOL. The risk that sutures looped around haptics will slip off the haptic is thereby avoided.

Electroconvulsive therapy in children and adolescents: results from a population­based study utilising the Swedish National Quality Register.

Electroconvulsive therapy (ECT) is effective and safe for adults with severe depression, but less studied in adolescents. Here, we examined the indications, prevalence, practice, response and remission rates, and side effects in young people treated with ECT in Sweden. We also examined the usage of ECT in the transition to adult psychiatry. Using data from national patient registers and the Swedish National Quality Register for ECT (Q-ECT), we identified patients aged up to 19 years treated with ECT over a 5-year study period. Response and remission rates were analysed using the Clinical Global Impression (7-point scale)-Improvement (CGI-I) and Severity (CGI-S). A total of 118 individuals were identified, of which 105 were also enrolled in the Q-ECT. The most common indication for ECT was depression (68%; n = 80). Adolescents aged < 18 years were more severely ill before treatment than those aged 18 years (P < 0.01). Three of the hospitals in Sweden treated the majority of adolescents < 18 years old. The median number of sessions in each ECT series was seven. Unilateral placement of the electrodes was the most common (88%; n = 99). Fifty-seven percent (n = 54) of the patients responded (CGI-I, 1-2) to the treatment; remission (CGI-S, 1-2) was achieved by 32% (n = 30). Psychotic symptoms were associated with a higher response rate in patients with depression (P = 0.038). A deterioration of memory compared to pre-treatment was reported in six patients. ECT was associated with high response and remission rates in adolescents with severe psychiatric disorders after non-response to medication.

Postoperative Endophthalmitis in Immediate Sequential Bilateral Cataract Surgery: A Nationwide Registry Study.

PURPOSE: To report the incidence of postoperative endophthalmitis (PE) after immediate sequential bilateral cataract surgery (ISBCS) in Sweden. DESIGN: Retrospective cohort registry study. PARTICIPANTS: Patient data from 1 457 172 cataract extractions, including 1 364 934 unilateral surgeries and 92 238 ISBCSs. METHODS: Endophthalmitis cases reported to the Swedish National Cataract Register (NCR) during a 16-year period (2002-2017) were analyzed in comparison to all control cases with regard to patient characteristics, surgical technique, and capsule complication. MAIN OUTCOME MEASURE: Incidence and determinants for PE in ISBCS compared with unilateral surgeries. RESULTS: A total of 422 cases of PE were identified in 1 457 172 cataract extractions, yielding an overall incidence of 0.029% (95% confidence interval [CI], 0.0262-0.0317). For unilateral procedures, the rate was 0.0299% (95% CI, 0.0270-0.0328) or 408 cases in 1 364 934 operations, whereas that for ISBCS was 0.0152% (95% CI, 0.0072-0.0231) or 14 incidents in 92 238 operations (P = 0.01). In a logistic regression model including all cataract procedures, nonuse of intracameral (IC) antibiotics (ABs), capsule complication, age 85 years or more, male gender, and ocular comorbidity were found to be independent risk factors for PE. All these parameters were less frequent in ISBCS. Notwithstanding, in the same multivariate analysis, ISBCS in itself was associated with a significantly lower risk for PE. At follow-up, 5 of the 14 PE cases in the ISBCS cohort had a visual acuity (VA) of 20/200 or worse. Of these, one 93-year-old ISBCS patient developed bilateral infection. CONCLUSIONS: After ISBCS in Sweden, PE occurred once in 6600 surgeries. The risk of sustaining a final VA of 20/200 or less was 1 incident in 18 000 operated eyes. When counseling potential ISBCS patients about the risk of PE, it seems reasonable to state that the reported risk in the literature is lower than that with unilateral surgery but not negligible. Precautions remain necessary.

Methods and Strategies for Reducing Seclusion and Restraint in Child and Adolescent Psychiatric Inpatient Care.

Restraints and seclusions are restrictive interventions used in psychiatric inpatient units when there is an imminent risk of harm to the patient or others. Coercive measures are controversial and can lead to negative consequences, including negative emotions, re-traumatization, injuries, or death. The article summarizes the last 10 years of literature regarding methods and strategies used for reducing seclusions and restraints in child and adolescent psychiatric inpatient units, and reports on their outcomes. The literature was reviewed by searching PubMed and PsycInfo for English-language articles published between May 2010 and May 2020. Eighteen articles were found that described methods or strategies aimed at reducing restraint or seclusion utilization in child and adolescent psychiatric inpatient units. The following interventions were evaluated: Trauma-Informed Care (TIC), Six Core Strategies, Child and Family Centered Care (CFCC), Collaborative & Proactive Solutions (CPS), Strength-Based Care, Modified Positive Behavioral Interventions and Supports (M-PBIS), Behavioral Modification Program (BMP), Autism Spectrum Disorder Care Pathway (ASD-CP), Dialectical Behavior Therapy (DBT), sensory rooms, Mindfulness-Based Stress Reduction Training (MBSR) of staff, and Milieu Nurse-Client Shift Assignments. Most of the interventions reduced the use of seclusions and/or restraints. Two child-centered and trauma-informed initiatives eliminated the use of mechanical restraints. This review shows that the use of coercive measures can be reduced and should be prioritized. Successful implementation requires ongoing commitment on all levels of an organization and a willingness to learn. To facilitate comparisons, future models should evaluate different standardized parameters.

"Seeing a Brighter Future" - Experiences of Adolescents with Common Mental Disorders Receiving the Problem-Solving Therapy "Youth Friendship Bench" in Zimbabwe.

In Zimbabwe common mental disorders are prevalent among adolescents and the treatment gap is large. The recently introduced Youth Friendship Bench intervention (YouFB) addresses this gap by task-shifting youth lay health workers to offer a culturally contextualised, manual-based, six-session problem-solving therapy to adolescents, 16-19 years of age. The aim of this study was to explore participants´ experiences of YouFB to attain a first insight into this novel intervention. Interviews with nine adolescents were analysed using qualitative content analysis on a latent level. The experience of YouFB was positive, perceived to offer hope and relief from feelings of isolation and uncertainty, increase manageability of problems, and contribute to feelings of autonomy, resulting in a feeling of optimism about the future. The notion among participants that this brief intervention had such a positive influence on their lives, sparks interest because of its applicability in low-resource settings.

Clinical safety and efficacy of a hydrophilic acrylic intraocular lens in a real-world population: a 1-year follow-up retro-prospective study.

BACKGROUND: This multicentre, retro-prospective real-world study evaluated the visual, refractive and safety outcomes of a monofocal lens 1 year after implantation in cataract patients with or without pre-existing ocular pathologies. METHODS: Records from 4 centres in Germany and Sweden were reviewed to select eyes with aged-related cataracts, having undergone crystalline lens extraction by phacoemulsification and implantation of a CT ASPHINA 409 IOL. Preoperative, 1-month and 3-month postoperative data was collected retrospectively. In addition, included patients attended a prospective visit 12 months or later after surgery. The examination included: monocular uncorrected (UDVA) and corrected distance visual acuity (CDVA), subjective refraction, slit-lamp examination, optical biometry, intraocular pressure (IOP), endothelial cell count and postoperative complications. RESULTS: 282 eyes, including 94 with pre-existing ocular pathologies, were analysed. Twelve months after the surgery, 95% of eyes achieved monocular CDVA equal or better than 0.3 logMAR, mean postoperative CDVA was 0.06 ± 0.17 logMAR, and mean UDVA 0.31 ± 0.29 logMAR. Visual acuity outcomes were better in eyes with no pre-existing ocular pathologies, but both groups showed a statistically significant improvement after surgery compared with preoperative values (p ≤ 0.002). The mean sphere and spherical equivalent values also improved significantly postoperatively (p = 0.003). Overall, 62.1% of eyes had spherical equivalent within ±0.5 D and 80.9% within ±1.0 D. The IOL was stable in the capsular bag as demonstrated by tilt and decentration measurements. IOP, corneal status, and endothelial cell count values were in the normal range. Nd:YAG treatment was performed on 9.9% of the eyes. CONCLUSION: The implantation of the monofocal CT ASPHINA 409 IOL was beneficial to restore vision in eyes with or without concomitant ocular pathology such as macular degeneration, glaucoma, Sicca syndrome, epiretinal membrane, cornea guttata, or amblyopia. Good to excellent long-term visual and refractive outcomes, and a low rate of complications in both healthy and pathological eyes were found 12 months after the surgery. TRIAL REGISTRATION: Trial registered on under the identification NCT03145103 (date of registration 9 May 2017).

A 15-year follow-up of former self-harming inpatients in child & adolescent psychiatry - a qualitative study.

Purpose: Self-harm is common among adolescents, and is even more frequent among psychiatric populations. The aim of this study was to increase knowledge and understanding of different aspects of life for adults who, when adolescents, had engaged in severe self-harm during inpatient stays.Material and methods: Individual semi-structured interviews were held with seven former inpatients with a history of severe self-harm during inpatient stay in their adolescence. The interviews were analysed using a qualitative method, and the results were described in the form of categories and sub-categories.Results: Five categories, with 16 sub-categories, were found to be related to the former patients' experiences of their lives. At the time of the interviews, the subjects were in their early thirties and had no ongoing self-harm. In childhood they had experienced a dysfunctional relationship with one or both of their parents, and self-harm was one of several destructive behaviours. Friendships outside the unit were difficult during adolescence. Soon after admission to the psychiatric inpatient unit, relationships with other patients became important and contributed to them wanting to stay at the unit. Meaningful relationships and being part of a social context with healthy expectations were seen as important factors for stopping self-harm at a later stage. The subjects' experiences of their life today ranged from not enjoying it to accepting their current situation.Conclusion: These findings are based on a small sample, but they indicate the importance of relationships and the social context in contributing to and then ending self-harm.

Parenting stress and its correlates in an infant mental health unit: a cross-sectional study.

Background: An infant's development is closely linked to the relationship they have with their parents. Parenting stress, affective disorder, and an upbringing with substance-abusing parents can affect parenting quality and increase the risk of children developing behavioral, mental and social problems. The overall aim of the study was to investigate how parents of children attending an outpatient Infant Mental Health (IMH) unit rate their own psychological health and parenting stress, and to explore predictors of parenting stress.Methods: The sample comprised 197 parents, 129 mothers and 68 fathers, referred with their infant/toddler to an outpatient IMH unit for interplay treatment. On admission, the parents completed self-report questionnaires concerning their own mental health problems and parenting stress.Results: The mothers reported significantly more psychiatric symptoms and parenting stress than the fathers. Fathers with substance-abusing parents had often experienced divorce in the family of origin, had a low level of education, and had often experienced trauma. Depression was a predictor for parenting stress for both mothers and fathers.Conclusion: The parents' situation was strained, presenting a variety of psychiatric symptoms and high levels of parenting stress, making assessment of parental health before starting treatment important. The mothers' situations were more serious compared with the fathers', and for both parents depression was a significant predictor for parenting stress. To increase the chances of a positive treatment outcome for the child, both parents should be included in the treatment.

Tachykinin upregulation in atopic dermatitis.

Context: Atopic dermatitis (AD) is a chronic, inflammatory, itching skin disorder, which may worsen due to stress, depression and anxiety. Tachykinins may be involved in inflammation signaling as well as they may have a role in stress, depression and anxiety. Objective: This study aimed to measure the expression of tachykinin markers, in the skin of patients with AD, and the correlation of these tachykinins with clinical and psychodemographic parameters. Materials and methods: Twenty-eight adult patients with AD were investigated regarding tachykinin expression in skin biopsies, using an immunohistochemical technique. The patients were characterized with clinical and psychodemographic parameters. Results: The number of substance P and neurokinin (NK)A positive nerve fibers, as well as NKA positive mononuclear dermal cells, was increased in lesional compared to non-lesional skin. Interestingly, the depression score and the number of dermal NK-1 receptor (R) positive cells in lesional as well as in non-lesional skin showed a correlation. Conclusion: These findings indicate an upregulation of the tachykinergic system in the inflamed skin of AD.

Evaluation of clinical outcomes following implantation of a sub-2-mm hydrophilic acrylic MICS intraocular lens.

PURPOSE: To evaluate clinical outcomes following sub-2-mm microincision cataract surgery (MICS) and intraocular lens (IOL) implantation. SETTING: Five EU clinical sites. DESIGN: Prospective, multicenter, open-label, single-arm, non-randomized. METHODS: Preoperative assessment involved visual acuity (VA), intraocular pressure and biometry measurements. 1.4-mm wound-assisted or 1.8-mm MICS was performed. Follow-up visits were made 1 day, 1-2 weeks, 1-2 and 4-6 months after surgery. The incision size, corrected distance VA (CDVA), uncorrected distance VA, manifest refraction spherical equivalent (MRSE), refraction predictability/stability and IOL decentration were assessed. At 12-, 18-, and 24-month, long-term centration, posterior capsular opacification (PCO) and Nd:YAG capsulotomy rates were investigated. RESULTS: A total of 103 eyes were implanted with the study IOL (INCISE, Bausch & Lomb), 96 of which were included in visual outcome analysis. A mean 6-month CDVA of - 0.02 logMAR (20/20 + 1) was observed and 75 eyes (79.8%) and 93 eyes (98.3%) achieved a visual acuity of at least 20/20 or 20/40. Mean MRSE was - 0.20 ± 0.60 D. Mean absolute predictive error was 0.44 ± 0.36 D, with 90.4% within 1.00 D of target. Mean total decentration was 0.35 ± 0.36 mm at 6 months and 0.32 ± 0.14 mm at 24 months (p > 0.05). 24-month evaluation of posterior capsular opacification score was 0.03 for the central area. A Nd:YAG rate of 3.4% was observed at 24 months. CONCLUSIONS: The new MICS IOL provided excellent visual outcomes and was safe and effective for the sub-2-mm procedure. The MICS IOL demonstrated long-term centration, stability and a low rate of PCO development.

Quantitative assessment of DNA damage in the industrial ethanol production strain Saccharomyces cerevisiae PE-2.

Lignocellulosic hydrolysates remain one of the most abundantly used substrates for the sustainable production of second generation fuels and chemicals with Saccharomyces cerevisiae. Nevertheless, fermentation inhibitors such as acetic acid, furfural and hydroxymethylfurfural are formed during the process and can lead to slow or stuck fermentations and/or act as genotoxic agents leading to production strain genetic instability. We have developed a novel dominant deletion (DEL) cassette assay for quantification of DNA damage in both wild-type and industrial yeast strains. Using this assay, the ethanol production strain S. cerevisiae PE-2 was shown to be more resistant to hydrogen peroxide and furfural than the laboratory DEL strain RS112. Indeed, the PE-2 strain also showed a lower tendency for recombination, consistent with a more efficient DNA protection. The dominant DEL assay presented herein should prove to be a useful tool in the selection of robust yeast strains and process conditions for second generation feedstock fermentations.

HAA1 and PRS3 overexpression boosts yeast tolerance towards acetic acid improving xylose or glucose consumption: unravelling the underlying mechanisms.

Acetic acid tolerance and xylose consumption are desirable traits for yeast strains used in industrial biotechnological processes. In this work, overexpression of a weak acid stress transcriptional activator encoded by the gene HAA1 and a phosphoribosyl pyrophosphate synthetase encoded by PRS3 in a recombinant industrial Saccharomyces cerevisiae strain containing a xylose metabolic pathway was evaluated in the presence of acetic acid in xylose- or glucose-containing media. HAA1 or PRS3 overexpression resulted in superior yeast growth and higher sugar consumption capacities in the presence of 4 g/L acetic acid, and a positive synergistic effect resulted from the simultaneous overexpression of both genes. Overexpressing these genes also improved yeast adaptation to a non-detoxified hardwood hydrolysate with a high acetic acid content. Furthermore, the overexpression of HAA1 and/or PRS3 was found to increase the robustness of yeast cell wall when challenged with acetic acid stress, suggesting the involvement of the modulation of the cell wall integrity pathway. This study clearly shows HAA1 and/or, for the first time, PRS3 overexpression to play an important role in the improvement of industrial yeast tolerance towards acetic acid. The results expand the molecular toolbox and add to the current understanding of the mechanisms involved in higher acetic acid tolerance, paving the way for the further development of more efficient industrial processes.

Serotonergic Markers in Atopic Dermatitis.

Stress and anxiety may worsen atopic dermatitis (AD) through the serotonin system. Serotonergic expression was measured in 28 patients with AD in relation to extent of the disease (SCORing of Atopic Dermatitis; SCORAD), pruritus intensity (visual analogue scale; VAS), anxiety traits (Swedish Universities Scales of Personality; SSP) and depression (Montgomery-Åsberg Depression Rating Scale-Self assessment; MADRS-S). Biopsies were taken from lesional and non-lesional AD skin, and investigated for expression of serotonin, its receptors 5-HT1A and 5-HT2, and serotonin transporter protein (SERT), using immunohistochemistry. 5-HT1AR-immunoreactivity (ir) was higher in lesional skin in apical epidermis and in mast cell-like cells in dermis, and 5-HT2AR-ir in apical epidermis and on blood vessels. In contrast, a basement membrane 5-HT2AR-ir signal was higher in non-lesional skin. The distribution of SERT-ir in the basal epidermal layer was higher in lesional skin. Positive and negative correlations were found between serotonergic markers and SCORAD, inflammation, pruritus intensity, anxiety traits, and depression score, indicating that serotonergic mechanisms are involved in AD.

Dose-Dependent Protective and Inductive Effectsof Xanthohumol on Oxidative DNA Damage inSaccharomyces cerevisiae.

The effect of xanthohumol, a prenylflavonoid isolated from the hop plant (Humulus lupulus L.), on Saccharomyces cerevisiae DNA oxidative damage and viability was evaluated. Yeast cultures under oxidative stress, induced by H2O2, displayed stronger growth in the presence of 5 mg/L of xanthohumol than cultures with only H2O2. Likewise, DNA damage assessed by the comet assay was significantly lower in cells co-incubated with xanthohumol and H2O2. Accordingly, fluorescence of dichlorofluorescein in cells treated with H2O2 and xanthohumol was considerably lower than in cells exclusively treated with H2O2, indicative of a reactive oxygen species scavenging mechanism and consequent formation of oxidation products, as detected by mass spectrometry. However, at concentrations above 5 mg/L, xanthohumol elicited an opposite effect, leading to a slower growth rate and significant increase in DNA damage. A yeast yap1 deletion mutant strain sensitive to oxidative stress grew more slowly in the presence of at least 5 mg/L of xanthohumol than cultures of the wild type, suggesting that xanthohumol toxicity is mediated by oxidative stress. This evidence provides further insight into the impact of xanthohumol on yeast cells, supporting dose-dependent antioxidant/antigenotoxic and prooxidant/genotoxic effects.

Toward Treatment Integrity: Developing an Approach to Measure the Treatment Integrity of a Dialectical Behavior Therapy Intervention With Homeless Youth in the Community.

The current paper discusses an approach to measuring treatment integrity of dialectical behavioral therapy (DBT) when implemented within two programs providing services to street-involved youth in the community. Measuring treatment integrity is a critical component of effective implementation of evidence-based interventions in clinical practice, since sound treatment integrity increases confidence in client outcomes and intervention replicability. Despite being an essential part of implementation science, few studies report on treatment integrity, with limited research addressing either measurement tools or maintenance of treatment integrity. To address the lack of available treatment integrity measures, researchers in the current study developed and piloted a treatment integrity measure which pertain to the individual and group components of DBT. A total of 20 recordings were assessed using the treatment integrity measure. Results indicate that the community agency staff (e.g. youth workers, social workers & nurses) implemented the intervention as intended; increasing confidence in the outcome variables, the staffs' training and the replicability of the intervention. This article offers one approach to addressing treatment integrity when implementing evidence-based interventions, such as DBT in a community setting, and discusses the need for effective and feasible integrity measures that can be adopted in order to strengthen mental health practice in community settings.

Pydna: a simulation and documentation tool for DNA assembly strategies using python.

BACKGROUND: Recent advances in synthetic biology have provided tools to efficiently construct complex DNA molecules which are an important part of many molecular biology and biotechnology projects. The planning of such constructs has traditionally been done manually using a DNA sequence editor which becomes error-prone as scale and complexity of the construction increase. A human-readable formal description of cloning and assembly strategies, which also allows for automatic computer simulation and verification, would therefore be a valuable tool. RESULTS: We have developed pydna, an extensible, free and open source Python library for simulating basic molecular biology DNA unit operations such as restriction digestion, ligation, PCR, primer design, Gibson assembly and homologous recombination. A cloning strategy expressed as a pydna script provides a description that is complete, unambiguous and stable. Execution of the script automatically yields the sequence of the final molecule(s) and that of any intermediate constructs. Pydna has been designed to be understandable for biologists with limited programming skills by providing interfaces that are semantically similar to the description of molecular biology unit operations found in literature. CONCLUSIONS: Pydna simplifies both the planning and sharing of cloning strategies and is especially useful for complex or combinatorial DNA molecule construction. An important difference compared to existing tools with similar goals is the use of Python instead of a specifically constructed language, providing a simulation environment that is more flexible and extensible by the user.

Genotoxic effect of photodynamic therapy mediated by curcumin on Candida albicans.

Photodynamic therapy (PDT) is a promising method for localized and specific inactivation of fungi and bacteria. A nontoxic light-sensitive compound is taken up by cells, which are then exposed selectively to light, which activates toxicity of the compound. We investigated the potential of sublethal PDT using light-sensitive curcumin (CUR) in combination with blue (455 nm) light to promote reactive oxygen species (ROS) formation in the form of singlet oxygen and DNA damage of Candida albicans. Surprisingly, CUR-mediated PDT but also light alone caused significantly longer comet tails, an indication of DNA damage of C. albicans when compared with the negative control. The intracellular ROS production was also significantly higher for the group treated only with light. However, PDT compared to blue light alone significantly slowed DNA repair. Comet tails decreased during 30 min visualized as a 90% reduction in length in the absence of light for cells treated with light alone, while comet tails of cells treated with PDT only diminished in size about 45%. These results indicate that complex mechanisms may result in PDT in a way that should be considered when choosing the photosensitive compound and other aspects of the treatment design.

Simultaneous imaging of amyloid-ß and lipids in brain tissue using antibody-coupled liposomes and time-of-flight secondary ion mass spectrometry.

The spatial localization of amyloid-ß peptide deposits, the major component of senile plaques in Alzheimer's disease (AD), was mapped in transgenic AD mouse brains using time-of-flight secondary ion mass spectrometry (ToF-SIMS), simultaneously with several endogenous molecules that cannot be mapped using conventional immunohistochemistry imaging, including phospholipids, cholesterol and sulfatides. Whereas the endogenous lipids were detected directly, the amyloid-ß deposits, which cannot be detected as intact entities with ToF-SIMS because of extensive ion-induced fragmentation, were identified by specific binding of deuterated liposomes to antibodies directed against amyloid-ß. Comparative investigation of the amyloid-ß deposits using conventional immunohistochemistry and fluorescence microscopy suggests similar sensitivity but a more surface-confined identification due to the shallow penetration depth of the ToF-SIMS signal. The recorded ToF-SIMS images thus display the localization of lipids and amyloid-ß in a narrow (~10 nm) two-dimensional plane at the tissue surface. As compared to a frozen nontreated tissue sample, the liposome preparation protocol generally increased the signal intensity of endogenous lipids, likely caused by matrix effects associated with the removal of salts, but no severe effects on the tissue integrity and the spatial distribution of lipids were observed with ToF-SIMS or scanning electron microscopy (SEM). This method may provide an important extension to conventional tissue imaging techniques to investigate the complex interplay of different kinds of molecules in neurodegenerative diseases, in the same specimen. However, limitations in target accessibility of the liposomes as well as unspecific binding need further consideration.

Imaging of distribution of topically applied drug molecules in mouse skin by combination of time-of-flight secondary ion mass spectrometry and scanning electron microscopy.

In the development of topical drugs intended for local effects in the skin, one of the major challenges is to achieve drug penetration through the external barrier of the skin, stratum corneum, and secure exposure to the viable skin layers. Mass spectrometric imaging offers an opportunity to study drug penetration in a variety of skin models by mapping the spatial distribution in different skin layers after topical application of the drug. In this study, we used time-of-flight secondary ion mass spectrometry (TOF-SIMS) and scanning electron microscopy (SEM) to image the distribution of three drug molecules in skin tissue cross sections of inflamed mouse ear. The three compounds, roflumilast, tofacitinib, and ruxolitinib, were topically administered to the mouse ears, which were subsequently cryosectioned and thawed for the analyses. The results reveal that the combination of TOF-SIMS and SEM was beneficial for interpretation of drug distribution. SEM identified the different skin layers, while spatial distributions of all three compounds could be visualized by TOF-SIMS, showing that the drug was primarily distributed into, or on the top of, the stratum corneum. Imaging of endogenous skin components like cholesterol, phospholipids, ceramides, and free fatty acids showed distributions in good agreement with the literature. One limitation of the TOF-SIMS method is sensitivity, typically allowing for analysis in the millimolar range rather than the pharmacologically relevant micromolar range. However, the data presented demonstrate the potential of the technique for studying the penetration of drugs with different physicochemical properties in skin.