FIBER-ML, an Open-Source Supervised Machine Learning Tool for Quantification of Fibrosis in Tissue Sections

Pathologic fibrosis is a major hallmark of tissue insult in many chronic diseases. Although the amount of fibrosis is recognized as a direct indicator of the extent of disease, there is no consentaneous method for its quantification in tissue sections. This study tested FIBER-ML, a semi-automated, open-source freeware that uses a machine-learning approach to quantify fibrosis automatically after a short user-controlled learning phase. Fibrosis was quantified in sirius red-stained tissue sections from two fibrogenic animal models: acute stress-induced cardiomyopathy in rats (Takotsubo syndrome-like) and HIV-induced nephropathy in mice (chronic kidney disease). The quantitative results of FIBER-ML software version 1.0 were compared with those of ImageJ in Takotsubo syndrome, and with those of inForm in chronic kidney disease. Intra- and inter-operator and inter-software correlation and agreement were assessed. All correlations were excellent (>0.95) in both data sets. The values of discriminatory power between the pathologic and healthy groups were <10^-3 for data on Takotsubo syndrome and <10^-4 for data on chronic kidney disease. Intra-operator agreement, assessed by intra-class coefficient correlation, was good (>0.8), while inter-operator and inter-software agreement ranged from moderate to good (>0.7). FIBER-ML performed in a fast and user-friendly manner, with reproducible and consistent quantification of fibrosis in tissue sections. It offers an open-source alternative to currently used software, including quality control and file management.

Vector-apodizing phase plate coronagraph: design, current performance, and future development [Invited]

Over the last decade, the vector-apodizing phase plate (vAPP) coronagraph has been developed from concept to on-sky application in many high-contrast imaging systems on 8 m class telescopes. The vAPP is a geometric-phase patterned coronagraph that is inherently broadband, and its manufacturing is enabled only by direct-write technology for liquid-crystal patterns. The vAPP generates two coronagraphic point spread functions (PSFs) that cancel starlight on opposite sides of the PSF and have opposite circular polarization states. The efficiency, that is, the amount of light in these PSFs, depends on the retardance offset from a half-wave of the liquid-crystal retarder. Using different liquid-crystal recipes to tune the retardance, different vAPPs operate with high efficiencies (${\gt}96\%$) in the visible and thermal infrared (0.55 µm to 5 µm). Since 2015, seven vAPPs have been installed in a total of six different instruments, including Magellan/MagAO, Magellan/MagAO-X, Subaru/SCExAO, and LBT/LMIRcam. Using two integral field spectrographs installed on the latter two instruments, these vAPPs can provide low-resolution spectra (${\rm{R}} \sim 30$) between 1 µm and 5 µm. We review the design process, development, commissioning, on-sky performance, and first scientific results of all commissioned vAPPs. We report on the lessons learned and conclude with perspectives for future developments and applications.

Cytotoxic CD8+ T cells promote granzyme B-dependent adverse post-ischemic cardiac remodeling

Acute myocardial infarction is a common condition responsible for heart failure and sudden death. Here, we show that following acute myocardial infarction in mice, CD8⁺ T lymphocytes are recruited and activated in the ischemic heart tissue and release Granzyme B, leading to cardiomyocyte apoptosis, adverse ventricular remodeling and deterioration of myocardial function. Depletion of CD8⁺ T lymphocytes decreases apoptosis within the ischemic myocardium, hampers inflammatory response, limits myocardial injury and improves heart function. These effects are recapitulated in mice with Granzyme B-deficient CD8⁺ T cells. The protective effect of CD8 depletion on heart function is confirmed by using a model of ischemia/reperfusion in pigs. Finally, we reveal that elevated circulating levels of GRANZYME B in patients with acute myocardial infarction predict increased risk of death at 1-year follow-up. Our work unravels a deleterious role of CD8⁺ T lymphocytes following acute ischemia, and suggests potential therapeutic strategies targeting pathogenic CD8⁺ T lymphocytes in the setting of acute myocardial infarction.

Immune cells contribute to adverse remodeling following myocardial infarction. Here the authors show in mice and pigs that CD8⁺ lymphocytes release Granzyme B in the infarcted heart leading to cardiomyocyte death, enhanced inflammation and deterioration of cardiac function.

Isolated tubal twist: A case series of a rare event occurring at different times in reproductive life

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Isolated fallopian tube torsion is a rare but potentially serious event occurring at different times in reproductive life.

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This diagnosis is often overlooked before surgery.

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It should be evoked in front acute pelvic pain in patients with history of hydrosalpinx or paratubal cyst.

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Conservative management must be privileged especially in woman of childbearing age and in a pediatric population.

Introduction and importance

Isolated fallopian tube torsion (IFTT) is a rare but potentially serious cause of pelvic pain in women. Despite being a surgical emergency, this diagnosis is often overlooked before surgery. To raise awareness of this diagnosis among clinicians, we describe here five cases, which occurred at different times in reproductive life.

Cases presentation

We present five cases of isolated fallopian tube torsion at different ages (13–54 years). It often manifests with sudden onset of acute pelvic pain in four cases and chronic pelvic pain in one case.

At admission, patients were suspected of adnexal torsion (3 cases), genital infection (1 case), and renal pain (1 case). CT-scan showed IFTT in only one patient. Laparoscopic surgical management, performed by experienced surgeons, consisted of salpingectomy in 4 cases and conservative treatment in one case. The latter was complicated with hydrosalpinx 6 years later. All patients were followed in outpatient clinic at least one time after surgery and had favorable outcomes.

Clinical discussion

Given the rarity of the pathology and the lack of pathognomonic imaging, IFTT is rarely diagnosed before surgery. Its etiology is still unknown but hydrosalpinx following an infectious process seems to be a major risk factor.

Conclusion

Increasing awareness of this rare entity is advocated, especially in woman of reproductive age. Torsion should be evoked in front acute pelvic pain in patients with hydrosalpinx or paratubal cyst. Conservative management must be privileged especially in women of childbearing age and in pediatric population.

P5369Alpha-V integrin regulates the contribution of PW1+ cells to cardiac fibrosis

Background

Activated cardiac fibroblasts produce extracellular matrix proteins that accumulate during cardiac fibrosis. We have recently shown that PW1 is expressed in a subset of cardiac stromal cells and that cardiac PW1+ cells represent a cellular source of fibroblasts in the ischemic hearts.

Purpose

We aimed to further identify new cell surface markers expressed by cardiac PW1+ cells and to investigate their role in the fibrogenic behavior of these cells.

Methods and results

We first performed transcriptomic and proteomic profiling of FACS-isolated cardiac PW1+ from normal and ischemic hearts. RNA-sequencing output files were processed with bioinformatics algorithms to identify 378 specific cell-surface markers for cardiac PW1+ cells. By comparing these candidates with the proteomic profile, we then cross-identified 9 cell surface proteins primarily involved in cell motility, adhesion to the matrix, inflammatory response and response to wounding. One of these candidates (i.e., aV-integrin or CD51) was expressed in almost all cardiac PW1+ cells (93±1%), and was predominantly found in cells expressing PW1 in the myocardium. Cardiac PW1+ cells showed a predominant expression of aVβ1 complex which is known to mediate fibrosis through TGF-beta activation in a number of tissues. The transfer of isolated cardiac PW1+CD51+ cells into ischemic hearts was associated with fibrosis development. We further demonstrated that inhibition of aV-integrin in cardiac PW1+ cells reduces their profibrotic gene expression profile and their ability to differentiate into fibroblasts. Lastly, a pharmacological blockade of aV-integrin improved cardiac function and animal survival following myocardial infarction coupled with a reduced infarct size and fibrotic lesion.

Conclusions

These data identify a targetable pathway that regulates cardiac fibrosis in response to an ischemic injury and demonstrate that pharmacological inhibition of aV-integrin leads to reduced pathological outcomes following cardiac ischemia.

Acknowledgement/Funding

Fondation Leducq (grant 13CVD01, CardioStemNet project), Fédération Française de Cardiologie and Era-CVD (ANR-16-ECVD-0011-03, Clarify project)

Improvement of Dystrophic Muscle Fragility by Short-Term Voluntary Exercise through Activation of Calcineurin Pathway in mdx Mice

Dystrophin deficiency in mdx mice, a model for Duchenne muscular dystrophy, leads to muscle weakness revealed by a reduced specific maximal force as well as fragility (ie, higher susceptibility to contraction-induced injury, as shown by a greater force decrease after lengthening contractions). Both symptoms could be improved with dystrophin restoration-based therapies and long-term (months) voluntary exercise. Herein, we evaluated the effect of short-term (1-week) voluntary wheel running. We found that running improved fragility of tibialis anterior muscle (TA), but not plantaris muscle, independently of utrophin up-regulation, without affecting weakness. Moreover, TA muscle excitability was also preserved by running, as shown by compound muscle action potential measurements after lengthening contractions. Of interest, the calcineurin inhibitor cyclosporin A prevented the effect of running on both muscle fragility and excitability. Cyclosporin also prevented the running-induced changes in expression of genes involved in excitability (Scn4a and Cacna1s) and slower contractile phenotype (Myh2 and Tnni1) in TA muscle. In conclusion, short-term voluntary exercise improves TA muscle fragility in mdx mice, without worsening weakness. Its effect was related to preserved excitability, calcineurin pathway activation, and changes in the program of genes involved in excitability and slower contractile phenotype. Thus, remediation of muscle fragility of Duchenne muscular dystrophy patients through appropriate exercise training deserves to be explored in more detail.