Graft cell expansion from hiPSC-RPE strip after transplantation in primate eyes with or without RPE damage.

Clinical studies using suspensions or sheets of human pluripotent cell-derived retinal pigment epithelial cells (hiPSC-RPE) have been conducted globally for diseases such as age-related macular degeneration. Despite being minimally invasive, cell suspension transplantation faces challenges in targeted cell delivery and frequent cell leakage. Conversely, although the RPE sheet ensures targeted delivery with correct cell polarity, it requires invasive surgery, and graft preparation is time-consuming. We previously reported hiPSC-RPE strips as a form of quick cell aggregate that allows for reliable cell delivery to the target area with minimal invasiveness. In this study, we used a microsecond pulse laser to create a local RPE ablation model in cynomolgus monkey eyes. The hiPSC-RPE strips were transplanted into the RPE-ablated and intact sites. The hiPSC-RPE strip stably survived in all transplanted monkey eyes. The expansion area of the RPE from the engrafted strip was larger at the RPE injury site than at the intact site with no tumorigenic growth. Histological observation showed a monolayer expansion of the transplanted RPE cells with the expression of MERTK apically and collagen type 4 basally. The hiPSC-RPE strip is considered a beneficial transplantation option for RPE cell therapy.

Detection sensitivity of fluorescence lifetime imaging ophthalmoscopy for laser-induced selective damage of retinal pigment epithelium.

PURPOSE: To investigate the sensitivity of fluorescence lifetime imaging ophthalmoscopy (FLIO) to detect retinal laser spots by comparative analysis with other imaging modalities. METHODS: A diode laser with a wavelength of 514 nm was applied with pulse durations of 5.2, 12, 20, and 50 µs. The laser pulse energy was increased so that the visibility of the laser spot by slit-lamp fundus examination (SL) under the irradiator's observation covers from the subvisible to visible range immediately after irradiation. The irradiated areas were then examined by fundus color photography (FC), optical coherence tomography (OCT), fundus autofluorescence (AF), FLIO, and fluorescein angiography (FA). The visibility of a total of over 2200 laser spots was evaluated by two independent researchers, and effective dose (ED) 50 laser pulse energy values were calculated for each imaging modality and compared. RESULTS: Among examined modalities, FA showed the lowest mean of ED50 energy value and SL the highest, that is, they had the highest and lowest sensitivity to detect retinal pigment epithalium (RPE)-selective laser spots, respectively. FLIO also detected spots significantly more sensitively than SL at most laser pulse durations and was not significantly inferior to FA. AF was also often more sensitive than SL, but the difference was slightly less significant than FLIO. CONCLUSION: Considering its high sensitivity in detecting laser spots and previously reported potential of indicating local wound healing and metabolic changes around laser spots, FLIO may be useful as a non-invasive monitoring tool during and after minimally invasive retinal laser treatment.

Artificial Intelligence in Fluorescence Lifetime Imaging Ophthalmoscopy (FLIO) Data Analysis-Toward Retinal Metabolic Diagnostics.

The purpose of this study was to investigate the possibility of implementing an artificial intelligence (AI) approach for the analysis of fluorescence lifetime imaging ophthalmoscopy (FLIO) data even with small data. FLIO data, including the fluorescence intensity and mean fluorescence lifetime (τm) of two spectral channels, as well as OCT-A data from 26 non-smokers and 28 smokers without systemic and ocular diseases were used. The analysis was performed with support vector machines (SVMs), a well-known AI method for small datasets, and compared with the results of convolutional neural networks (CNNs) and autoencoder networks. The SVM was the only tested AI method, which was able to distinguish τm between non-smokers and heavy smokers. The accuracy was about 80%. OCT-A data did not show significant differences. The feasibility and usefulness of the AI in analyzing FLIO and OCT-A data without any apparent retinal diseases were demonstrated. Although further studies with larger datasets are necessary to validate the results, the results greatly suggest that AI could be useful in analyzing FLIO-data even from healthy subjects without retinal disease and even with small datasets. AI-assisted FLIO is expected to greatly advance early retinal diagnosis.

Clinical Landscape of Central Serous Chorioretinopathy in Germany: Retina.net CSC Registry Report Number 1.

INTRODUCTION: The German Registry of central serous chorioretinopathy (CSC) collects data on CSC patients in a nationwide multicenter approach to analyze epidemiology, risk factors, clinical presentations, as well as diagnosis and treatment patterns. METHODS: In this multicenter cohort study, patients with CSC were enrolled in nine tertiary referral centers in Germany between January 2022 and June 2023. After consenting to the study, demographic data, risk factors, reported symptoms, best-corrected visual acuity (BCVA), funduscopic findings, disease severity, and diagnostic and treatment decisions were recorded and analyzed. RESULTS: A total of 539 eyes of 411 CSC patients were enrolled in this study including 308 males (75%) and 103 females (25%). Patients were predominantly of Caucasian origin and had a mean age of 55.5 years (IQR 41.0-70.0). 28% of eyes were classified as acute (<4 months duration) CSC, 28% as chronic (>4 months duration) CSC, 21% as inactive CSC, 11% as chronic atrophic CSC, and 12% as CSC with secondary CNV. 128 patients (31%) demonstrated bilateral CSC. The most common risk factors reported were psychological stress (52%), smoking (38%), arterial hypertension (38%), and a history of or current use of steroids (30%). Most frequently encountered symptoms included decreased visual acuity (76%), metamorphopsia (49%), relative scotoma (47%), blurred vision (19%), and dyschromatopsia (9%). The mean logMAR BCVA on initial examination was 0.2 (≈20/30, IQR 0.2-0.4) but showed significant variation with a tendency of lower BCVA in chronic cases. At the baseline visit, 74% of the overall cohort received no treatment, while 19% underwent local treatment and only 2% underwent systemic treatment. Of the local therapies, anti-VEGF injections were the most frequently performed procedure (33%, mainly for secondary CNV), followed by micropulse laser (28%), focal nonpulsed laser (23%), verteporfin photodynamic therapy (14%), and nonsteroidal anti-inflammatory eye drops (2%). Among intravitreal anti-VEGF agents, aflibercept was used most frequently, followed by bevacizumab and ranibizumab. CONCLUSION: This registry represents one of the largest cohorts of European patients with CSC to date. Patient age and the proportion of women were higher than expected and bilateral active disease was lower than anticipated, highlighting that neither age nor gender should be overemphasized when diagnosing CSC. Therapeutic interventions are heterogeneous and include verteporfin photodynamic therapy, micropulse laser, and anti-VEGF injections in case of secondary CNV.

Timing of initial symptom onset during milk and wheat challenges: A retrospective study.

BACKGROUND: Allergic reactions to milk appear sooner than those to hen's eggs, irrespective of the total dose of the oral food challenges (OFCs) and type of matrices. The reported median times for the first symptom occurrence are 20-30 min with milk and 50-60 min with eggs. However, allergic reactions due to wheat have not yet been fully investigated. METHODS: This study retrospectively collected data from OFC for milk and wheat conducted at Sagamihara National Hospital and Sendai Medical Center from 2009 to 2023. The time from the start of the OFC to the onset of symptoms was compared between children with cow's milk and wheat allergy. RESULTS: Twenty-five and 13 children reacted to single-dose OFCs with milk products equivalent to 25 mL of raw cow's milk or 15 g of udon noodles, respectively. The median ages of patients with positive challenges were 1.4 and 2.8 years for milk and wheat, respectively, and the median times for the first symptom occurrence were 20 min and 53 min, respectively (p = .006). CONCLUSION: This multicenter study was the first to examine the time of symptom appearance during single-medium-dose milk and wheat challenges. Allergic reactions to wheat appear later than those for milk during OFC. For multiadministration OFC for wheat, the dosing interval should be longer than 60 min. Our findings can help improve the safety of OFCs.

Fluorescence Lifetime Imaging Ophthalmoscopy of Mouse Models of Age-related Macular Degeneration.

Purpose: To investigate fluorescence lifetime of mouse models of age-related macular degeneration (AMD) by fluorescence lifetime imaging ophthalmoscopy (FLIO). Methods: Two AMD mouse models, apolipoprotein E knockout (ApoE-/-) mice and NF-E2-related factor-2 knockout (Nrf2-/-) mice, and their wild-type mice underwent monthly ophthalmic examinations including FLIO from 3 months of age. After euthanasia at the age of 6 or 11 months, blood plasma was collected to determine total antioxidant capacity and eyes were enucleated for Oil red O (ORO) lipid staining of chorioretinal tissue. Results: In FLIO, the mean fluorescence lifetime (τm) of wild type shortened with age in both spectral channels. In short spectral channel, τm shortening was observed in both AMD models as well, but its rate was more pronounced in ApoE-/- mice and significantly different from the other strains as months of age progressed. In contrast, in long spectral channel, both model strains showed completely opposite trends, with τm becoming shorter in ApoE-/- and longer in Nrf2-/- mice than the others. Oil red O staining at Bruch's membrane was significantly stronger in ApoE-/- mice at 11 months than the other strains. Plasma total antioxidant capacity was highest in ApoE-/- mice at both 6 and 11 months. Conclusions: The two AMD mouse models exhibited largely different fundus fluorescence lifetime, which might be related to the different systemic metabolic state. FLIO might be able to indicate different metabolic states of eyes at risk for AMD. Translational Relevance: This animal study may provide new insights into the relationship between early AMD-associated metabolic changes and FLIO findings.

Physician approval for pregnancy in patients with systemic lupus erythematosus showing only serological activity: A vignette survey study.

OBJECTIVE: The European League Against Rheumatism recommends that the disease activity of systemic lupus erythematosus should be stable before pregnancy because complications and disease flares increase if pregnancy occurs while disease activity is high. However, some patients have ongoing serological activity even after treatment. Herein, we investigated how physicians decide on the acceptability of pregnancy in patients showing only serological activity. METHODS: A questionnaire was administered from December 2020 to January 2021. It included the characteristics of physicians, facilities, and the allowance for pregnancies of patients using vignette scenarios. RESULTS: The questionnaire was distributed to 4946 physicians, and 9.4% responded. The median age of respondents was 46 years, and 85% were rheumatologists. Pregnancy allowance was significantly affected by the duration of the stable period and status of serological activity [duration: proportion difference 11.8 percentage points (p.p.), P < .001; mild activity: proportion difference -25.8 p.p., P < .001; high activity: proportion difference -65.6 p.p., P < .001]. For patients with high-level serological activity, 20.5% of physicians allowed pregnancy if there were no clinical symptoms for 6 months. CONCLUSIONS: Serological activity had a significant effect on the acceptability of pregnancy. However, some physicians allowed patients with serological activity alone to become pregnant. Further observational studies are required to clarify such prognoses.

Impact of cigarette smoking on fluorescence lifetime of ocular fundus.

Cigarette smoking is known to adversely affect cellular metabolism and is a risk factor for various retinal diseases. Fluorescence lifetime imaging ophthalmoscopy (FLIO) has the potential to detect metabolic changes in the ocular fundus. Aim of this study was to analyze the influence of cigarette smoking on fluorescence lifetime (FLT) of healthy eyes using FLIO. Twenty-six non-smokers and 28 smokers aged between 20 and 37 years without systemic and ocular diseases were investigated by FLIO (excitation: 473 nm, emission: short spectral channel (SSC) 498-560 nm, long spectral channel (LSC) 560-720 nm). The FLT at the ETDRS grid regions were analyzed and compared. In SSC, the mean FLT (τm) of smokers was significantly longer in the ETDRS inner ring region, whereas the τm in LSC was significantly shorter in the outer ring. For the long component (τ2), smokers with pack year < 7.11 showed significantly shorter τ2 in SSC than non-smokers and the smokers with pack year ≥ 7.11. There were no significant differences in retinal thickness. The lack of obvious structural differences implies that the observed FLT changes are likely related to smoking-induced metabolic changes. These results suggest that FLIO may be useful in assessing retinal conditions related to lifestyle and systemic metabolic status.

Neurodevelopmental associations of prenatal and postnatal methylmercury exposure among first-grade children in the Kinan region, Japan.

The most severe effects of methylmercury (MeHg) exposure during child development are thought to result from exposure during fetal life and childhood. However, comparing the neurodevelopmental effects of prenatal and postnatal MeHg exposure (PreMeHg and PostMeHg, respectively) remains unclear. We aimed to investigate the associations between neurodevelopmental indicators and PreMeHg or PostMeHg. The participants were 134 children in the first grade of elementary schools aged 7-8 years from the Kinan region, an area with high consumption of MeHg-rich whales and tunas in Japan. We measured MeHg levels in preserved umbilical cord tissues and total mercury (T-Hg) levels in children's hair to estimate PreMeHg and PostMeHg levels, respectively. Neuropsychological (intelligence quotient testing and Boston Naming Test) and neurophysiological (brainstem auditory evoked potential [BAEP], visual evoked potential [VEP], and color vision tests) studies were performed to evaluate the neurodevelopmental status. Multiple regression analyses were conducted according to sex. The geometric mean MeHg levels in preserved umbilical cord tissues and T-Hg levels in children's hair were 0.11 µg/g and 2.94 µg/g, respectively. Neither PreMeHg nor PostMeHg was related to neuropsychological indicators. Some associations between MeHg exposure and neurophysiological results were observed only in boys. N145 latency in VEPs was significantly prolonged with increasing PreMeHg (ß: 12.01, 95% confidence interval [CI]: 0.648, 23.38). The III-V interpeak intervals in BAEP were significantly prolonged with increasing PreMeHg or PostMeHg (ß [95% CI]: 0.142 [0.041, 0.243] and 0.159 [0.052, 0.265], respectively). After adjusting for PreMeHg, the association between PostMeHg and BAEP latencies disappeared. In conclusion, the latency in the auditory and visual pathways was significantly prolonged with increasing PreMeHg in boys. These findings suggest that male fetuses may be more susceptible to MeHg exposure.

Single-trial neuromagnetic analysis reveals somatosensory dysfunction in chronic Minamata disease.

Methylmercury pollution is a global problem, and Minamata disease (MD) is a stark reminder that exposure to methylmercury can cause irreversible neurological damage. A "glove and stocking type" sensory disturbance due to injured primary sensory cortex (SI) (central somatosensory disturbance) is the most common neurologic sign in MD. As this sign is also prevalent in those with polyneuropathy, we aimed to develop an objective assessment for detecting central somatosensory disturbances in cases of chronic MD. We selected 289 healthy volunteers and 42 patients with MD. We recorded the sensory nerve action potentials (SNAPs) and somatosensory evoked magnetic fields (SEFs) to median nerve stimulation with magnetoencephalography. Single-trial epochs were classified into three categories (N20m, non-response, and P20m epochs) based on the cross-correlation between averaged sensor SEFs and individual epochs. We assessed SI responses (the appearance rate of P20m [P20m rate] and non-response epochs [non-response rate]) and early somatosensory cortical processing (N20m amplitude, reproducibility of N20m in single-trial responses [cross-correlation value], and induced gamma-band oscillations of the SI [gamma response] of single epochs excluding non-response epochs). Receiver operating characteristic curve analyses were used to examine the diagnostic accuracy of each parameter. We found that SNAPs exerted a marginal effect on the N20m. The N20m amplitude, cross-correlation value, and gamma response were significantly reduced in the MD group on either side (p < 0.0001), suggestive of altered early somatosensory cortical processing. Interestingly, the P20m rate and non-response rate were significantly increased in the MD group on either side (p < 0.0001), thereby suggesting impaired SI responses. Notably, P20m and absent N20m peaks were observed in 6 and 11 patients with MD, respectively, which may be attributed to increased numbers of P20m epochs. The cross-correlation value exhibited the highest correlation with the P20m rate or non-response rate. Thus, reduced reproducibility of N20m may play an important role in chronic MD. The cross-correlation value exhibited the highest correlation with the gamma response for both SI parameters in early somatosensory cortical processing. The area under the curve was > 0.77 (range: 0.77-0.79) for all parameters. Their confidence intervals overlapped with each other; thus, each SEF parameter likely had an approximately equivalent discrimination ability. In conclusion, chronic MD is characterized by impaired SI responses and alterations in early somatosensory cortical processing. Thus, single-trial neuromagnetic analysis of somatosensory function may be useful for detecting central somatosensory disturbance and elucidating the relevant pathophysiological mechanisms even in the context of chronic MD.

Comparative Treatment Study on Macular Edema Secondary to Branch Retinal Vein Occlusion by Intravitreal Ranibizumab with and without Selective Retina Therapy.

The purpose of this study was to compare the safety and efficacy of selective retina therapy (SRT) combined with the intravitreal injection of ranibizumab (IVR) in patients with macular edema (ME) secondary to branch retinal vein occlusion (BRVO). This trial was a 12-month single-center, randomized, single-masked prospective study. Eligible patients were randomized (1:1) to IVR and SRT (IVR + SRT group), or IVR and sham SRT (IVR + sham group). After the initial IVR, all participants received ME resolution criteria-driven pro re nata treatment. SRT or sham SRT was always applied one day after IVR. The primary outcome measure of this study was the mean change in central macular thickness (CMT) from baseline, and the secondary outcome measures were the mean change in visual acuity from baseline and the number of IVR treatments at a 52-week follow-up. Thirteen patients were in the IVR + SRT group, and 11 were in the IVR + sham group. Compared to the baseline, mean CMT and BCVA improved significantly after 52 weeks in both groups, with no significant difference between the two groups. The mean number of IVR was 2.85 ± 1.52 in the IVR + SRT group and 4.73 ± 2.33 in the IVR + sham group at the 52-week follow-up, with a significant difference between the two groups (p < 0.05). IVR combined with SRT may significantly decrease the number of IVR treatments while maintaining the visual and anatomical improvement effect of IVR monotherapy.

Relationship between serum allergen-specific immunoglobulin E and threshold dose in an oral food challenge.

BACKGROUND: Several studies have reported threshold doses for food allergens. However, evidence regarding potential risk factors for low threshold doses is limited. Moreover, the relationship between threshold dose and specific immunoglobulin E (sIgE) levels to causative foods remains unclear. This study examined the relationship and the risk factors for a low threshold dose. METHODS: We recruited children with food allergies and examined the risk factors for a positive oral food challenge (OFC) with a low threshold dose and anaphylaxis. RESULTS: We evaluated 2501 children with food allergies (1667 [67%] boys; median age, 4.9 years) to eggs (n = 1096), milk (n = 671), wheat (n = 370), peanuts (n = 258), walnuts (n = 65), and cashews (n = 41). Of these patients, 234 (9%) reacted to ≤30 mg protein of causative foods and 620 (25%) reacted to ≤100 mg protein of causative foods. The sIgE level to causative foods was a significant independent factor for positive OFCs with a threshold dose of ≤30 mg for milk, wheat, and peanuts; ≤ 100 mg for eggs, milk, wheat, peanuts, and cashews; and anaphylaxis from eggs, milk, wheat, peanuts, and walnuts. High sIgE levels to causative foods were associated with a lower threshold dose of the OFC and anaphylaxis during the OFC. CONCLUSIONS: Approximately 9% of patients reacted to ≤30 mg protein of causative foods. The potential risks of anaphylaxis should be considered during OFCs for patients with elevated sIgE levels.

Pathophysiological conditions induced by SARS-CoV-2 infection reduce ACE2 expression in the lung.

SARS-CoV-2 infection causes a variety of physiological responses in the lung, and understanding how the expression of SARS-CoV-2 receptor, angiotensin-converting enzyme 2 (ACE2), and its proteolytic activator, transmembrane serine protease 2 (TMPRSS2), are affected in patients with underlying disease such as interstitial pneumonia will be important in considering COVID-19 progression. We examined the expression of ACE2 and TMPRSS2 in an induced usual interstitial pneumonia (iUIP) mouse model and patients with IPF as well as the changes in whole-lung ACE2 and TMPRSS2 expression under physiological conditions caused by viral infection. Histopathological and biochemical characteristics were analyzed using human specimens from patients with IPF and precision-cut lung slices (PCLS) from iUIP mouse model showing UIP with honeycombing and severe fibrosis after non-specific interstitial pneumonia. ACE2 expression decreased with acute lung inflammation and increased in the abnormal lung epithelium of the iUIP mouse model. ACE2 is also expressed in metaplastic epithelial cells. Poly(I:C), interferons, and cytokines associated with fibrosis decreased ACE2 expression in PCLS in the iUIP model. Hypoxia also decreases ACE2 via HIF1α in PCLS. Antifibrotic agent, nintedanib attenuates ACE2 expression in invasive epithelial cells. Patients with IPF are at a higher risk of SARS-CoV-2 infection due to the high expression of ACE2. However, ACE2 and TMPRSS2 expression is decreased by immune intermediaries, including interferons and cytokines that are associated with viral infection and upon administration of antifibrotic agents, suggesting that most of the viral infection-induced pathophysiological responses aid the development of resistance against SARS-CoV-2 infection.

CTLA-4-Ig internalizes CD80 in fibroblast-like synoviocytes from chronic inflammatory arthritis mouse model.

CD80 interact with CD28 and CTLA-4 on antigen-presenting cells, and function in the co-stimulatory signaling that regulates T cell activity. CTLA-4-Ig is used to treat RA by blocking co-stimulatory signaling. Chronic inflammatory arthritis was induced in D1BC mice using low-dose arthritogenic antigens and treated with CTLA-4-Ig. We performed histopathology of the joints and lymph nodes, serological examination for rheumatoid factors, and flow cytometric analysis of isolated synovial cells, including CD45- FLSs and CD45+ synovial macrophages. CTLA-4-Ig treatment ameliorated the chronic inflammatory polyarthritis. There was a decrease in the number of infiltrating lymphoid cells in the joints as well as in the levels of RF-IgG associated with a decrease in the number of B cells in the lymph nodes; more than 15% of CD45- FLSs expressed CD80, and a small number of them expressed PD-L1, indicating the presence of PD-L1/CD80 cis-heterodimers in these cells. CTLA-4-Ig internalized CD80, but not PD-L1, in isolated synovial cells. Gene ontology analysis revealed that CTLA-4-Ig internalization did not significantly alter the expression of inflammation-related genes. The therapeutic effect of CTLA-4-Ig appears to extend beyond the lymph nodes into the inflamed synovial compartment through the synergistic inactivation of T cells by the CD80 and PD-L1 axes.

Temperature Increase and Damage Extent at Retinal Pigment Epithelium Compared between Continuous Wave and Micropulse Laser Application.

Continuous wave (CW) and microsecond pulse (MP) laser irradiations were compared regarding cell damage and laser-induced temperature rise at retinal pigment epithelium (RPE). The RPE of porcine RPE-choroid-sclera explants was irradiated with a 577 nm laser in CW or MP mode (5% or 15% duty cycle (DC)) for 20 ms or 200 ms at an average laser power of 20−90 mW. Cell viability was investigated with calcein-AM staining. Optoacoustic (OA) technique was employed for temperature measurement during irradiation. For 200 ms irradiation, the dead cell area (DCA) increased linearly (≈1600 µm2/mW) up to the average power of 40 mW for all modes without significant difference. From 50 mW, the increase of DCA of MP-5% significantly dropped to 610 µm2/mW (p < 0.05), likely due to the detected microbubble formation. OA temperature measurement showed a monotonic temperature increase in CW mode and a stepwise increase in MP mode, but no significant difference in the average temperature increase at the same average power, consistent with the temperature modeling. In conclusion, there is no difference in the average temperature rise between CW and MP modes at the same average power regardless of DC. At lower DC, however, more caution is required regarding mechanical damage due to microbubble formation.

Personalized management for unmet needs with food allergy.

PURPOSE OF REVIEW: Patients with food allergies are at risk of experiencing accidental allergic symptoms in real life. Low thresholds may be a risk factor for accidental allergic reactions. Therefore, the evaluation of this threshold is required for the management of food allergies. We have suggested a management approach to identify the threshold dose and the consumable dose, considering patient age and the severity of food allergies. RECENT FINDINGS: A younger age is a risk factor for accidental allergic reactions, and school-age children are likely to have a lower quality of life (QOL) than younger children. Additionally, patients with a low threshold may have difficulty in acquiring tolerance. We performed a stepwise oral food challenge (OFC) to evaluate the threshold and consumable doses for patients with food allergies. Performing a low-dose OFC for the first step would identify the dose that could be consumed at home safely and avoid the complete elimination of allergic foods. Identifying the threshold dose would be effective in managing the risk of accidental ingestion. For patients who react to low-dose OFC, low-dose oral immunotherapy (OIT) would be expected to prevent the experience of allergic reactions by accidental ingestion and consume medium doses safely. SUMMARY: For food allergy patients and their caregivers, identifying the consumable dose would help manage the diet and eliminate their anxiety. Low-dose OFC and low-dose OIT are effective and well tolerated, which would improve their QOL. Considering the severity of food allergy and age, determining a safe threshold with no reactions would meet the unmet needs of patients with food allergy.

Phase-Sensitive Measurements of Depth-Dependent Signal Transduction in the Inner Plexiform Layer.

Non-invasive spatially resolved functional imaging in the human retina has recently attracted considerable attention. Particularly functional imaging of bipolar and ganglion cells could aid in studying neuronal activity in humans, including an investigation of processes of the central nervous system. Recently, we imaged the activity of the inner neuronal layers by measuring nanometer-size changes of the cells within the inner plexiform layer (IPL) using phase-sensitive optical coherence tomography (OCT). In the IPL, there are connections between the neuronal cells that are dedicated to the processing of different aspects of the visual information, such as edges in the image or temporal changes. Still, so far, it was not possible to assign functional changes to single cells or cell classes in living humans, which is essential for studying the vision process. One characteristic of signal processing in the IPL is that different aspects of the visual impression are only processed in specific sub-layers (strata). Here, we present an investigation of these functional signals for three different sub-layers in the IPL with the aim to separate different properties of the visual signal processing. Whereas the inner depth-layer, closest to the ganglion cells, exhibits an increase in the optical path length, the outer depth-layer, closest to the bipolar cell layer, exhibits a decrease in the optical path length. Additionally, we found that the central depth is sensitive to temporal changes, showing a maximum response at a stimulation frequency of around 12.5 Hz. The results demonstrate that the signals from different cell types can be distinguished by phase-sensitive OCT.

Nintedanib induces gene expression changes in the lung of induced-rheumatoid arthritis-associated interstitial lung disease mice.

Nintedanib is a multi-tyrosine kinase inhibitor widely used to treat progressive fibrosing interstitial lung diseases because it slows the reduction in forced vital capacity. However, the prognosis for patients treated with nintedanib remains poor. To improve nintedanib treatment, we examined the effects of nintedanib on gene expression in the lungs of induced-rheumatoid arthritis-associated interstitial lung disease model mice, which develop rheumatoid arthritis and subsequent pulmonary fibrosis. Using next-generation sequencing, we identified 27 upregulated and 130 downregulated genes in the lungs of these mice after treatment with nintedanib. The differentially expressed genes included mucin 5B and heat shock protein 70 family genes, which are related to interstitial lung diseases, as well as genes associated with extracellular components, particularly the myocardial architecture, suggesting unanticipated effects of nintedanib. Of the genes upregulated in the nintedanib-treated lung, expression of regulatory factor X2, which is suspected to be involved in cilia movement, and bone morphogenetic protein receptor type 2, which is involved in the pathology of pulmonary hypertension, was detected by immunohistochemistry and RNA in situ hybridization in peripheral airway epithelium and alveolar cells. Thus, the present findings indicate a set of genes whose expression alteration potentially underlies the effects of nintedanib on pulmonary fibrosis. It is expected that these findings will contribute to the development of improved nintedanib strategies for the treatment of progressive fibrosing interstitial lung diseases.

Oxygen saturation targets in pediatric respiratory disease.

BACKGROUND: The present study aimed to assess the appropriate oxygen saturation target in patients with pediatric respiratory diseases by lowering the oxygen saturation target from SpO2 94% to 90%. No previous study has explored appropriate oxygen saturation targets in respiratory diseases other than bronchiolitis. METHODS: The present, prospective, single-arm intervention trial enrolled pediatric inpatients with bronchiolitis, bronchitis, pneumonia, and asthma. The oxygen saturation target was lowered from SpO2 94% to 90% after the patients' general condition improved. The patients continued to be observed for 12 h after achieving SpO2 94%. The duration from the first cut-off point (SpO2 90% for 12 h without oxygen) to the second cut-off point (SpO2 94% for 12 h) was then evaluated. RESULTS: In total, 248 patients completed the study. Patients with bronchiolitis, bronchitis, pneumonia, and asthma had an interval between the two cut-off points of 23.9, 15.5, 19.1, and 13.8 h, respectively, (mean 17.2 h; 95% confidence interval 15.0-19.5). CONCLUSIONS: In generally healthy children, setting the oxygen saturation target at SpO2 90% after confirming improvement in their general condition was safe. The time required for increasing SpO2 from 90% to 94% was longest in the patients with bronchiolitis.

Bimodal fibrosis in a novel mouse model of bleomycin-induced usual interstitial pneumonia.

Idiopathic pulmonary fibrosis is pathologically represented by usual interstitial pneumonia (UIP). Conventional bleomycin models used to study pathogenic mechanisms of pulmonary fibrosis display transient inflammation and fibrosis, so their relevance to UIP is limited. We developed a novel chronic induced-UIP (iUIP) model, inducing fibrosis in D1CC×D1BC transgenic mice by intra-tracheal instillation of bleomycin mixed with microbubbles followed by sonoporation (BMS). A bimodal fibrotic lung disease was observed over 14 wk, with an acute phase similar to nonspecific interstitial pneumonia (NSIP), followed by partial remission and a chronic fibrotic phase with honeycombing similar to UIP. In this secondary phase, we observed poor vascularization despite elevated PDGFRß expression. γ2PF- and MMP7-positive epithelial cells, consistent with an invasive phenotype, were predominantly adjacent to fibrotic areas. Most invasive cells were Scgb1a1 and/or Krt5 positive. This iUIP mouse model displays key features of idiopathic pulmonary fibrosis and has identified potential mechanisms contributing to the onset of NSIP and progression to UIP. The model will provide a useful tool for the assessment of therapeutic interventions to oppose acute and chronic fibrosis.