Validating instructional design and predicting student performance in histology education: Using machine learning via virtual microscopy.

As a part of modern technological environments, virtual microscopy enriches histological learning, with support from large institutional investments. However, existing literature does not supply empirical evidence of its role in improving pedagogy. Virtual microscopy provides fresh opportunities for investigating user behavior during the histology learning process, through digitized histological slides. This study establishes how students' perceptions and user behavior data can be processed and analyzed using machine learning algorithms. These also provide predictive data called learning analytics that enable predicting students' performance and behavior favorable for academic success. This information can be interpreted and used for validating instructional designs. Data on the perceptions, performances, and user behavior of 552 students enrolled in a histology course were collected from the virtual microscope, Cytomine®. These data were analyzed using an ensemble of machine learning algorithms, the extra-tree regression method, and predictive statistics. The predictive algorithms identified the most pertinent histological slides and descriptive tags, alongside 10 types of student behavior conducive to academic success. We used these data to validate our instructional design, and align the educational purpose, learning outcomes, and evaluation methods of digitized histological slides on Cytomine®. This model also predicts students' examination scores, with an error margin of <0.5 out of 20 points. The results empirically demonstrate the value of a digital learning environment for both students and teachers of histology.

[Ulcerative Zoon's balanitis]. / Balanite de Zoon ulcérée.

Zoon's balanitis is a rare genital dermatosis of unknown etiology, usually presenting as a red-orange macule or plaque with a «cayenne pepper¼ appearance on the glans and/or foreskin. Unfortunately, atypical presentations are not uncommon, including vegetating or ulcerative lesions. Usually, it affects middle-age to older uncircumcised men. Although it is a benign pathology, Zoon's balanitis may be superimposed on another inflammatory or neoplastic dermatosis. As topical treatments are generally non satisfactory and relapses are usual on treatment with-drawal, circumcision remains an interesting option with usually a rapid and complete remission of the symptoms.

La balanite de Zoon est une dermatose génitale peu fréquente d'étiologie inconnue, se présentant habituellement par une macule ou une plaque de couleur rouge- orange avec un aspect en «poivre de cayenne¼, sur le gland et/ou le prépuce. Néanmoins, des formes atypiques, végétantes ou ulcérées, sont possibles. Elle touche plus souvent l'homme d'âge moyen à avancé et non circoncis. Il s'agit d'une pathologie bénigne, mais qui peut se surajouter à d'autres dermatoses inflammatoires ou néoplasiques. Les traitements topiques ne sont pas très efficaces et entraînent généralement une récidive à l'arrêt, tandis que la circoncision permet souvent une disparition rapide et complète des symptômes.

Effects of Minocycline Hydrochloride as an Adjuvant Therapy for a Guided Bone Augmentation Procedure in The Rat Calvarium.

This in vivo study reports the influence of minocycline-HCl administration on extra-skeletal bone generation in a Guided Bone Augmentation model, utilizing titanium caps placed on the intact as well as perforated calvaria of rats. The test group was administered 0.5 mg/mL minocycline-HCl with the drinking water, and the amount of bone tissue in the caps was quantified at three time points (4, 8 and 16 weeks). A continuously increased tissue fill was observed in all groups over time. The administration of minocycline-HCl as well as perforation of the calvaria increased this effect, especially with regard to mineralization. The strongest tissue augmentation, with 1.8 times that of the untreated control group, and, at the same time, the most mineralized tissue (2.3× over untreated control), was produced in the combination of both treatments, indicating that systemic administration of minocycline-HCl has an accelerating and enhancing effect on vertical bone augmentation.

Re-Evaluating the Relevance of the Oxygen-Glucose Deprivation Model in Ischemic Stroke: The Example of Cdk Inhibition.

Previous research has shown that cyclin-dependent kinases (Cdks) that play physiological roles in cell cycle regulation become activated in post-mitotic neurons after ischemic stroke, resulting in apoptotic neuronal death. In this article, we report our results using the widely used oxygen-glucose deprivation (OGD) in vitro model of ischemic stroke on primary mouse cortical neurons to investigate whether Cdk7, as part of the Cdk-activating kinase (CAK) complex that activates cell cycle Cdks, might be a regulator of ischemic neuronal death and may potentially constitute a therapeutic target for neuroprotection. We found no evidence of neuroprotection with either pharmacological or genetic invalidation of Cdk7. Despite the well-established idea that apoptosis contributes to cell death in the ischemic penumbra, we also found no evidence of apoptosis in the OGD model. This could explain the absence of neuroprotection following Cdk7 invalidation in this model. Neurons exposed to OGD seem predisposed to die in an NMDA receptor-dependent manner that could not be prevented further downstream. Given the direct exposure of neurons to anoxia or severe hypoxia, it is questionable how relevant OGD is for modeling the ischemic penumbra. Due to remaining uncertainties about cell death after OGD, caution is warranted when using this in vitro model to identify new stroke therapies.

Design, Synthesis, and Evaluation of Novel Pyruvate Dehydrogenase Kinase Inhibitors.

AIMS: The present work describes the synthesis and the biological evaluation of novel compounds acting as pyruvate dehydrogenase kinase (PDK) inhibitors. These drugs should become a new therapeutic approach for the treatment of pathologies improved by the control of the blood lactate level. METHODS: Four series of compounds belonging to N-(4-(N-alkyl/aralkylsulfamoyl)phenyl)-2- methylpropanamides and 1,2,4-benzothiadiazine 1,1-dioxides were prepared and evaluated as PDK inhibitors. RESULTS: The newly synthesized N-(4-(N-alkyl/aralkylsulfamoyl)phenyl)-2-methylpropanamides structurally related to previously reported reference compounds 4 and 5 were found to be potent PDK inhibitors (i.e. 10d: IC50 = 41 nM). 1,2,4-Benzothiadiazine 1,1-dioxides carrying a (methyl/ trifluoromethyl)-propanamide moiety at the 6-position were also designed as conformationally restricted ring-closed analogues of N-(4-(N-alkyl/aralkylsulfamoyl)phenyl)-2-hydroxy-2-methylpropanamides. Most of them were found to be less potent than their ring-opened analogues. Interestingly, the best choice of hydrocarbon side chain at the 4-position was the benzyl chain, providing 11c (IC50 = 3.6 µM) belonging to "unsaturated" 1,2,4-benzothiadiazine 1,1-dioxides, and 12c (IC50 = 0.5 µM) belonging to "saturated' 1,2,4-benzothiadiazine 1,1-dioxides. CONCLUSION: This work showed that ring-closed analogues of N-(4-(N-alkyl/aralkylsulfamoyl) phenyl)- 2-hydroxy-2-methylpropanamides were less active as PDK inhibitors than their corresponding ring-opened analogues. However, the introduction of a bulkier substituent at the 4-position of the 1,2,4-benzothiadiazine 1,1-dioxide core structure, such as a benzyl or a phenethyl side chain, was allowed, opening the way to the design of new inhibitors with improved PDK inhibitory activity.

Effects of Low Intensity Pulsed Ultrasound Stimulation on the Temporal Dynamics of Irradiated Bone Tissue Healing: A Histomorphometric Study in Rabbits.

The present study evaluated the influence of Low-Intensity Pulsed Ultrasound (LIPUS) on the regeneration processes of non-critical-size bone defects in irradiated and non-irradiated rabbit tibias. Bone defects were surgically created on both tibiae of six rabbits. The control group had no additional treatment. In one intervention group, one tibia was irradiated with 15 Gy in a single dose. A second group was treated with LIPUS, and a third with a combination of both treatments. The control samples showed 83.10% ± 17.79% of bone repair after 9 weeks, while the irradiated bone had regenerated significantly less during the same period (66.42% ± 29.36%). The LIPUS treatment on irradiated bones performed a 79.21% ± 21.07% bone fill and could not significantly improve the response compared to the non-treated irradiated specimens. However, LIPUS treatment on non-irradiated bone showed bone formations beyond the size defect (115.91% ± 33.69%), which was a highly significant increase when compared to the control group or any irradiated group. The application of ultrasound to healthy bone produced highly significant and enhanced bone formations with 36.70% more regenerated bone when compared to the same application on irradiated bone. LIPUS vibration stimuli may be considered as a promising complementary treatment approach in non-irradiated bone regeneration procedures to shorten the treatment and enhance bone healing. In irradiated bones, the effect of ultrasound application is less clear, and further studies are needed to refine the dynamics of the present results.

Cutaneous Breast Cancer Metastases Successfully Treated Using an Oxygen Flow Assisted Topical Administration of Methotrexate (OFAMTX).

INTRODUCTION: Cutaneous metastases of breast cancer remain a therapeutic challenge. Oxygen flow-assisted topical administration of methotrexate 5% (OFAMTX, 5% methotrexate in a carrier solution) has recently been proven to be an efficacious alternative treatment for extramammary Paget's disease, which is considered to be an in situ mammary adenocarcinoma of the epidermis. CASE REPORT: A 51-year-old patient with triple negative breast cancer presenting with biopsy-proven skin metastases on the chest agreed to a treatment with OFAMTX5%. The treatment duration was 2 weeks and consisted of twice-weekly sessions with OFAMTX5% applied to an area of skin of approximately 40 cm2. Skin biopsies were performed before and 2 months after procedure. The tolerance to the treatment was excellent, and no pain sensations were experienced. Two months post-procedure the treated area presented a post-inflammatory hyperpigmentation. No residual metastatic lesions were detectable on the control skin biopsy. Six months post-procedure the patient is still in clinical remission. DISCUSSION: OFAMTX5% represents an alternative skin-directed, painless, patient-friendly and efficacious adjuvant treatment for superficial metastatic lesions of breast cancer. Larger series are required to evaluate the potential of OFAMTX5% for the treatment of superficial metastatic lesions of breast cancer.

Exploratory Assessment of Oxygen Flow-Assisted Cutaneous Administration of Methotrexate for Superficial Basal Cell Carcinoma, Mycosis Fungoides, and Extramammary Paget Disease.

The molecular weight of methotrexate (MTX) makes cutaneous penetration difficult. Oxygen flow could enhance the skin permeation of MTX diluted in the proprietary LP3 carrier system. This pilot study aims to assess the efficacy, safety, and tolerance of oxygen flow-assisted LP3-MTX3% for treating superficial skin cancers. Patients with superficial basal cell carcinoma (n = 12), extramammary Paget disease (n = 5), classic mycosis fungoides (MF; n = 10), and folliculotropic MF (n = 6) were included in the study and were treated with four weekly applications of oxygen flow-assisted LP3-MTX3%. Photographs and biopsies were performed before and one month after treatment. At one month after treatment, the mean superficial basal cell carcinoma erythema-crusting-thickness clinical score, the extramammary Paget disease erythema-oozing-scaling/hyperkeratosis-pain/pruritus clinical score, and the modified composite assessment of index lesion severity classic MF and folliculotropic MF scores were improved by 77.5% ± 17.1% (P < 0.0001), 66.7% ± 22.9% (P = 0.011), 51.3% ± 32.2% (P = 0.0007), and 27.8% ± 32.0% (P = 0.086), respectively. At one month after treatment, histology revealed partial and total clearances for superficial basal cell carcinoma (1/12, 11/12), extramammary Paget disease (4/5, 1/5), classic MF (8/10, 2/10), and folliculotropic MF (6/6, 0/6). Tolerance was excellent and no pain was observed. MTX was never detectable in serum at baseline and 1, 2, 3, 8, 24, 48, and 72 hours post-treatment. In conclusion, the interesting therapeutic efficacy of oxygen flow-assisted LP3-MTX3% for treating superficial basal cell carcinoma, extramammary Paget disease, and MF lesions prompts further studies on a larger scale.

Four-color multiplex real-time PCR assay prototype targeting azithromycin resistance mutations in Mycoplasma genitalium.

BACKGROUND: The worldwide expansion of macrolide-resistant Mycoplasma genitalium (MG) in cases of genital infections has led to an increased recurrence rate of these infections after first-line azithromycin treatment. By detecting the presence of azithromycin-resistant MG, the patient's antibiotic treatment can be targeted and the spread of resistance prevented. With this aim in mind, macrolide-resistance detection kits are helpful tools for the physician. METHODS: Azithromycin resistance mutations in MG are targeted using a four-color multiplex real-time RT-PCR assay. Tested targets include plasmid DNA (as positive controls) as well as macrolide-sensitive and macrolide-resistant genomic DNA from characterized cell lines and clinical samples. RESULTS: The analytical data presented here were generated from plasmid DNA and genomic RNA/DNA and include adaptation to an internal control, specificity between targets, specificity vs non-MG species, limit of detection (LoD) and interference studies (co-infection and endogenous substances). The clinical data were based on the application of the assay to clinical samples characterized by sequencing. CONCLUSIONS: A new NAAT (nucleic acid amplification test) prototype has been developed in collaboration with the Diagenode s.a. company, this prototype targets MG and azithromycin-resistance mutations in that pathogen.

Growth Hormone (GH) Deficient Mice With GHRH Gene Ablation Are Severely Deficient in Vaccine and Immune Responses Against Streptococcus pneumoniae.

The precise impact of the somatotrope axis upon the immune system is still highly debated. We have previously shown that mice with generalized ablation of growth hormone (GH) releasing hormone (GHRH) gene (Ghrh-/-) have normal thymus and T-cell development, but present a marked spleen atrophy and B-cell lymphopenia. Therefore, in this paper we have investigated vaccinal and anti-infectious responses of Ghrh-/- mice against S. pneumoniae, a pathogen carrying T-independent antigens. Ghrh-/- mice were unable to trigger production of specific IgM after vaccination with either native pneumococcal polysaccharides (PPS, PPV23) or protein-PPS conjugate (PCV13). GH supplementation of Ghrh-/- mice restored IgM response to PPV23 vaccine but not to PCV13 suggesting that GH could exert a specific impact on the spleen marginal zone that is strongly implicated in T-independent response against pneumococcal polysaccharides. As expected, after administration of low dose of S. pneumoniae, wild type (WT) completely cleared bacteria after 24 h. In marked contrast, Ghrh-/- mice exhibited a dramatic susceptibility to S. pneumoniae infection with a time-dependent increase in lung bacterial load and a lethal bacteraemia already after 24 h. Lungs of infected Ghrh-/- mice were massively infiltrated by inflammatory macrophages and neutrophils, while lung B cells were markedly decreased. The inflammatory transcripts signature was significantly elevated in Ghrh-/- mice. In this animal model, the somatotrope GHRH/GH/IGF1 axis plays a vital and unsuspected role in vaccine and immunological defense against S. pneumoniae.

[A Massive Open Oneline Course (MOOC) on pratical histology: A goal, a tool, a large public ! Return on a first experience]. / Un « Massive Open Online Course ¼ (MOOC) sur des travaux pratiques en histologie : un objectif, un outil, un public varié ! Retour sur une première expérience.

A goal ! The MOOC entitled "Introduction to Histology, A Human Tissue Exploration" correspond to our vision of the practice of General Histology, which is based on the ability to diagnose 5 families of biological tissues. Ultimately, participants must be able to recognize the different types of cells and all the surrounding elements in order to understand how they organize themselves to form tissues with specific functions. A tool ! This know-how is based on reasoning from observations of microscopic structures. Learners are therefore invited to manipulate a virtual microscope to explore biological samples on histological slides digitized. Annotations, comments, drawings or photos are associated with landmarks that enrich the study of these histological sections. A target audience ! Two educational paths allow deepening the subject in a different way and thus matching the goals or motivations of each one. After a first year of experience, usage statistics and surveys of our learners show that the MOOC Histo has allowed each of them to find an interest and federate a community of motivated learners.

Role of Prion protein in premature senescence of human fibroblasts.

Prion protein (PrP) is essentially known for its capacity to induce neurodegenerative prion diseases in mammals caused by a conformational change in its normal cellular isoform (PrPC) into an infectious and disease-associated misfolded form, called scrapie isoform (PrPSc). Although its sequence is highly conserved, less information is available on its physiological role under normal conditions. However, increasing evidence supports a role for PrPC in the cellular response to oxidative stress. In the present study, a new link between PrP and senescence is highlighted. The role of PrP in premature senescence induced by copper was investigated. WI-38 human fibroblasts were incubated with copper sulfate (CuSO4) to trigger premature senescence. This induced an increase of PrP mRNA level, an increase of protein abundance of the normal form of PrP and a nuclear localization of the protein. Knockdown of PrP expression using specific small interfering RNA (siRNA) gave rise to appearance of several biomarkers of senescence as a senescent morphology, an increase of senescence associated ß-galactosidase activity and a decrease of the cellular proliferative potential. Overall these data suggest that PrP protects cells against premature senescence induced by copper.

Eruptive Seborrheic Keratoses Restricted to Plaque/Patch-Stage Mycosis Fungoides.

Eruptive seborrheic keratoses (ESK) are rare in dermatology. They are usually inflammatory in nature and may be encountered as Leser-Trélat sign. ESK may also be simultaneously observed with hepatic angiomas, chemotherapy, segmental neurofibromatosis, HIV or erythrodermic pityriasis rubra pilaris, psoriasis, and drug eruption. ESK may be transient and self-healing. Others recede after successful treatment of the underlying disease. In some instances, seborrheic keratoses may follow an isotopic response and remain strictly restricted to sites of previous eczema, photo-exposition or tattoos. A patient with patch/plaque lesions of classic-type mycosis fungoides (MF) presented sudden ESK that were exclusively limited to the MF lesions. In conclusion, this patient combined an isotopic response and ESK.

Exposure to Bacterial CpG DNA Protects from Airway Allergic Inflammation by Expanding Regulatory Lung Interstitial Macrophages.

Living in a microbe-rich environment reduces the risk of developing asthma. Exposure of humans or mice to unmethylated CpG DNA (CpG) from bacteria reproduces these protective effects, suggesting a major contribution of CpG to microbe-induced asthma resistance. However, how CpG confers protection remains elusive. We found that exposure to CpG expanded regulatory lung interstitial macrophages (IMs) from monocytes infiltrating the lung or mobilized from the spleen. Trafficking of IM precursors to the lung was independent of CCR2, a chemokine receptor required for monocyte mobilization from the bone marrow. Using a mouse model of allergic airway inflammation, we found that adoptive transfer of IMs isolated from CpG-treated mice recapitulated the protective effects of CpG when administered before allergen sensitization or challenge. IM-mediated protection was dependent on IL-10, given that Il10-/- CpG-induced IMs lacked regulatory effects. Thus, the expansion of regulatory lung IMs upon exposure to CpG might underlie the reduced risk of asthma development associated with a microbe-rich environment.

Lysozyme as a cotreatment during antibiotics use against vaginal infections: An in vitro study on Gardnerella vaginalis biofilm models.

Bacterial vaginoses are frequent in women, most of them involving Gardnerella vaginalis. In more than 50% of the cases, usual antibiotic treatments are not capable of eliminating completely the infection, leading to recurrent vaginosis. In addition to the appearance of antibiotic resistance, recurrence can be due to the development of a biofilm by G. vaginalis. In vitro experiments on G. vaginalis biofilms showed that the biofilm protected bacteria from the antibiotic clindamycin. Also, recombinant human lysozyme (rhLys) was able to both degrade biofilms and prevent their formation. This degradation effect persisted whenever other vaginal commensal or pathogenic microorganisms were added to the culture and on each tested clinical biofilm-producing strain of G. vaginalis. The co-administration of rhLys and clindamycin or metronidazole improved both antibiotics' efficiency and lysozyme-driven biofilm degradation. The comparison of both clindamycin and metronidazole antibacterial spectra showed that metronidazole was preferable to treat vaginosis. This suggests that human lysozyme could be added as an anti-biofilm cotreatment to vaginal antibiotherapy, preferably metronidazole, against Gardnerella vaginalis infection in vivo. [Int Microbiol 19(2): 101-107 (2016)].

Melanoma masquerading as nonmelanocytic lesions.

Increased awareness among dermatologists as well as the development of dermoscopy and sequential dermoscopy have contributed significantly toward an increase in the diagnostic accuracy of pigmented melanoma and even of amelanotic melanoma. However, the dermatologist's nightmare is the small group of melanomas that present as common skin diseases, often associated with a significant delay in diagnosis and hence a poor prognosis. The study was carried out to prospectively assess the number of melanomas lacking any clinical suspicion of melanoma and to describe their clinical and histological features over a 6-year observation period in an University Tertiary Skin Cancer Center. Out of 502 cases of newly diagnosed cases of melanoma, seven (1.4%) nonpigmented and nonamelanotic cases of melanoma were identified. The mean age of the patients was 69 years (two females/five males). All cases were discovered by chance on a punch biopsy. The clinical diagnostic suspicions were basal cell carcinoma, fungal intertrigo, keratoacanthoma, lichenoid keratoma, diabetic foot ulcer, eczema, and necrotic pressure ulcer. Dermoscopy, performed after the punch biopsies, was only partially contributive. The mean histological thickness was 2.7 mm, the mean number of mitoses was 7/mm, local micrometastases were present in 5/7 (71%), the mean Ki67 count was 18.9%, and a positive sentinel lymph node was observed in 4/6 (66%) cases. Nonpigmented and nonamelanotic melanomas are rare, are at high risk, and have a poor prognosis because of a delayed diagnosis. Dermoscopy is only of partial diagnostic aid. Treatment resistance or atypical behavior of the above-mentioned lesions should lead to biopsy.

The importance of the tumor microenvironment in the therapeutic management of cancer.

Tumor prognosis is generally defined by various tumor parameters. However, it is well known that paracrine, endocrine and cell-cell interactions between the tumor and its microenvironment contribute to its growth. The tumor microenvironment (TME) can also influence disease prognosis and is likely to be considered as an important prognostic factor. In addition, conventional therapies can influence the microenvironment and antitumor immunity. Similarly, the TME will influence the effectiveness of therapy. The purpose of this review is to demonstrate how TME is important in therapeutic management. Key interactions between TME and different cancer therapies as well as their current clinical consequences have been described. More research is needed to establish the important network between tumor cells and their environment to highlight their relationships with conventional therapies and develop global therapeutic strategies.

In vitro approach to study the synergistic effects of tobramycin and clarithromycin against Pseudomonas aeruginosa biofilms using prokaryotic or eukaryotic culture media.

Recurrent Pseudomonas aeruginosa infections involving biofilm formation are frequent in cystic fibrosis, aggravating the respiratory distress. Co-administration of clarithromycin and classical tobramycin could improve the health status of patients. Antibiotic toxicity was assessed on epithelial (CFBE41o(-)) and macrophagic (THP-1) cell lines. Non-toxic concentrations of antibiotics alone or in combination were applied twice daily for 12 days on mature (12-day-old) biofilms of three P. aeruginosa strains, developed either in prokaryotic culture broth [tryptic soy broth (TSB)] or in a eukaryotic cell culture medium (RPMI-FCS) more similar to an in vivo environment. The antibiofilm and bactericidal effects of antibiotics were assessed. No toxicity of tobramycin was observed on eukaryotic cell lines at concentrations up to 500µg/mL, whilst 100µg/mL was selected as the clarithromycin upper safe limit. The amount of biofilm was strongly reduced by 100µg/mL and 500µg/mL tobramycin for each strain in both media, whilst clarithromycin was only effective in RPMI-FBS, with synergistic (PAO1 strain) and additive (PYO2 strain) effects detected when combining tobramycin 4µg/mL and clarithromycin 100µg/mL. Finally, tobramycin at ≥100µg/mL exerted strong bactericidal effects on each strain in both media. Clarithromycin also exerted bactericidal effects on each strain in both media; its effect was weaker than tobramycin in TSB but was similar in RPMI-FBS. Synergistic effects were observed on PAO1 and MUCO biofilms, e.g. when combining tobramycin 4µg/mL and clarithromycin 100µg/mL. These in vitro data show that co-administration of clarithromycin and tobramycin acts synergistically against in vitro P. aeruginosa biofilms.