[Invasive squamous cell carcinoma: about 2 cases]

Conjunctival tumors are common in tropical areas, where exposure to ultraviolet radiation is high and almost permanent. Malignant tumors are quite rare and the most represented is conjunctival squamous cell carcinoma. We report two cases of invasive squamous cell carcinoma of the conjunctiva received in the ophthalmology department of the Sominé Dolo hospital in Mopti, Mali. The patients were 25 and 51 years old, living in a rural desert area exposed to sunlight and dust. They presented with a mass developed in the area of the palpebral fissure, invading the cornea and preventing palpebral occlusion. The mass was raised, multi-lobulated, well circumscribed, pearly white in color and papillomatous in appearance with dilation of the feeder vessels. A wide surgical excision at 4 - 5 mm from the healthy tissue edges was performed with anatomopathological examination of the specimen, which confirmed a mature and invasive differentiated squamous cell carcinoma of the conjunctiva. The extension workup and HIV serology were negative. The evolution was favorable in the medium term without recurrence.

[Eye traumatism during the COVID-19 sanitary crisis at Iota-teaching hospital]

INTRODUCTION

During the COVID-19 pandemic, we have witnessed a world-wide lock-down of the population. This government action combined with the application of social distancing should in principle reduce the frequency of occurrence of ocular injuries. The goal of our work is to try to understand the circumstances of the occurrence of ocular injuries at the IOTA Teaching Hospital during the lock-down period of the COVID-19 health crisis.

METHODOLOGY

This was a cross-sectional, descriptive study. The data were collected prospectively. Our study covered the period from March to May 2020. All consenting patients seen at the IOTA Teaching Hospital for ocular trauma regardless of gender, age, circumstances in which the trauma occurred or the nature of the injuries were included by non-probability sampling. Excluded from the study were patients who did not consent or who consulted for a non-traumatic ophthalmologic condition.

RESULTS

There were a total of 138 cases, of which 84 were male and 54 female, for a gender ratio of M/F=1.5. Children aged 0 to 5 years represented more than 3/4 (79.14%) of our sample. Trauma occurred in 45.83% of cases during leisure activities and 3.60% of cases involved domestic violence.

DISCUSSION

According to the authors, measures aimed at limiting public movement, particularly the curfews introduced by the Malian government to contain the spread of the COVID-19 pandemic, may actually result in trauma.

CONCLUSION

Raising public awareness of the social and psychological consequences of lock-down through audiovisual means might significantly reduce the frequency of these ocular traumas.

How microwaves can help to study membrane ageing

This paper studies original protocols of rapid PES/PVP membrane NaOCl degradation allowing at reaching ageing states that are representative of industrial ageing. The long term objective is to propose basis for further fundamental studies aiming at the improvement of the impact of membrane ageing on behaviour in UF (fouling and cleaning mastering). The key of several protocols is the use of ageing acceleration thanks to microwave irradiation, either continuous or pulsed ones, that can be further associated (or not) with short ageing time in UF conditions. To evaluate the representativeness of obtained aged membranes, comparisons are achieved between pristine, voluntary laboratory aged membranes and an industrial membrane at the end of its service-life. Several physico-chemical analyses were used (ATR-FTIR, SEM-EDX, contact angle, SEC-HPLC). Evaluation of UF performances were made in UF of a model protein (Lysozyme, 14,300 g.mol^-1). Finally, the proof of concept is done that conditions using MW exist to reach ageing state representative of industrial ageing.

A Chemical Probe for the ATAD2 Bromodomain

ATAD2 is a cancer-associated protein whose bromodomain has been described as among the least druggable of that target class. Starting from a potent lead, permeability and selectivity were improved through a dual approach: 1) using CF2 as a sulfone bio-isostere to exploit the unique properties of fluorine, and 2) using 1,3-interactions to control the conformation of a piperidine ring. This resulted in the first reported low-nanomolar, selective and cell permeable chemical probe for ATAD2.

GSK6853, a Chemical Probe for Inhibition of the BRPF1 Bromodomain

The BRPF (Bromodomain and PHD Finger-containing) protein family are important scaffolding proteins for assembly of MYST histone acetyltransferase complexes. A selective benzimidazolone BRPF1 inhibitor showing micromolar activity in a cellular target engagement assay was recently described. Herein, we report the optimization of this series leading to the identification of a superior BRPF1 inhibitor suitable for in vivo studies.

Cell Penetrant Inhibitors of the KDM4 and KDM5 Families of Histone Lysine Demethylases. 1. 3-Amino-4-pyridine Carboxylate Derivatives

Optimization of KDM6B (JMJD3) HTS hit 12 led to the identification of 3-((furan-2-ylmethyl)amino)pyridine-4-carboxylic acid 34 and 3-(((3-methylthiophen-2-yl)methyl)amino)pyridine-4-carboxylic acid 39 that are inhibitors of the KDM4 (JMJD2) family of histone lysine demethylases. Compounds 34 and 39 possess activity, IC50 ≤ 100 nM, in KDM4 family biochemical (RFMS) assays with ≥ 50-fold selectivity against KDM6B and activity in a mechanistic KDM4C cell imaging assay (IC50 = 6-8 μM). Compounds 34 and 39 are also potent inhibitors of KDM5C (JARID1C) (RFMS IC50 = 100-125 nM).

Structure-Based Optimization of Naphthyridones into Potent ATAD2 Bromodomain Inhibitors

ATAD2 is a bromodomain-containing protein whose overexpression is linked to poor outcomes in a number of different cancer types. To date, no potent and selective inhibitors of the bromodomain have been reported. This article describes the structure-based optimization of a series of naphthyridones from micromolar leads with no selectivity over the BET bromodomains to inhibitors with sub-100 nM ATAD2 potency and 100-fold BET selectivity.

Fragment-Based Discovery of Low-Micromolar ATAD2 Bromodomain Inhibitors

Overexpression of ATAD2 (ATPase family, AAA domain containing 2) has been linked to disease severity and progression in a wide range of cancers, and is implicated in the regulation of several drivers of cancer growth. Little is known of the dependence of these effects upon the ATAD2 bromodomain, which has been categorized as among the least tractable of its class. The absence of any potent, selective inhibitors limits clear understanding of the therapeutic potential of the bromodomain. Here, we describe the discovery of a hit from a fragment-based targeted array. Optimization of this produced the first known micromolar inhibitors of the ATAD2 bromodomain.

Tuberculosis specific responses following therapy for TB: Impact of HIV co-infection

Characterizing perturbations in the immune response to tuberculosis in HIV can develop insights into the pathogenesis of coinfection. HIV+ TB+ and TB monoinfected (TB+) subjects recruited from clinics in Bamako prior to initiation of TB treatment were evaluated at time-points following initiation of therapy. Flow cytometry assessed CD4+/CD8+ T cell subsets and activation markers CD38/HLA-DR. Antigen specific responses to TB proteins were assessed by intracellular cytokine detection and proliferation. HIV+ TB+ subjects had significantly higher markers of immune activation in the CD4+ and CD8+ T cells compared to TB+ subjects. HIV+ TB+ had lower numbers of TB-specific CD4+ T cells at baseline. Plasma IFNγ levels were similar between HIV+ TB+ and TB+ subjects. No differences were observed in in-vitro proliferative capacity to TB antigens between HIV+ TB+ and TB+ subjects. Subjects with HIV+ TB+ coinfection demonstrate in vivo expansion of TB-specific CD4+ T cells. Immunodeficiency associated with CD4+ T cell depletion may be less significant compared to immunosuppression associated with HIV viremia or untreated TB infection.

A selective jumonji H3K27 demethylase inhibitor modulates the proinflammatory macrophage response

The jumonji (JMJ) family of histone demethylases are Fe2+- and α-ketoglutarate-dependent oxygenases that are essential components of regulatory transcriptional chromatin complexes. These enzymes demethylate lysine residues in histones in a methylation-state and sequence-specific context. Considerable effort has been devoted to gaining a mechanistic understanding of the roles of histone lysine demethylases in eukaryotic transcription, genome integrity and epigenetic inheritance, as well as in development, physiology and disease. However, because of the absence of any selective inhibitors, the relevance of the demethylase activity of JMJ enzymes in regulating cellular responses remains poorly understood. Here we present a structure-guided small-molecule and chemoproteomics approach to elucidating the functional role of the H3K27me3-specific demethylase subfamily (KDM6 subfamily members JMJD3 and UTX). The liganded structures of human and mouse JMJD3 provide novel insight into the specificity determinants for cofactor, substrate and inhibitor recognition by the KDM6 subfamily of demethylases. We exploited these structural features to generate the first small-molecule catalytic site inhibitor that is selective for the H3K27me3-specific JMJ subfamily. We demonstrate that this inhibitor binds in a novel manner and reduces lipopolysaccharide-induced proinflammatory cytokine production by human primary macrophages, a process that depends on both JMJD3 and UTX. Our results resolve the ambiguity associated with the catalytic function of H3K27-specific JMJs in regulating disease-relevant inflammatory responses and provide encouragement for designing small-molecule inhibitors to allow selective pharmacological intervention across the JMJ family.

Fragment-based discovery of bromodomain inhibitors part 2: optimization of phenylisoxazole sulfonamides

Bromodomains are epigenetic reader modules that regulate gene transcription through their recognition of acetyl-lysine modified histone tails. Inhibitors of this protein-protein interaction have the potential to modulate multiple diseases as demonstrated by the profound anti-inflammatory and antiproliferative effects of a recently disclosed class of BET compounds. While these compounds were discovered using phenotypic assays, here we present a highly efficient alternative approach to find new chemical templates, exploiting the abundant structural knowledge that exists for this target class. A phenyl dimethyl isoxazole chemotype resulting from a focused fragment screen has been rapidly optimized through structure-based design, leading to a sulfonamide series showing anti-inflammatory activity in cellular assays. This proof-of-principle experiment demonstrates the tractability of the BET family and bromodomain target class to fragment-based hit discovery and structure-based lead optimization.

Seroprevalence of HIV/HBV coinfection in Malian blood donors

OBJECTIVES

A cross-sectional study was conducted to assess the prevalence of human immunodeficiency virus (HIV), hepatitis B virus (HBV), and their coinfection among blood donors at the National Blood Transfusion Center in Bamako, Mali, from November 2001 to July 2002.

METHODS

Enzyme-linked immunosorbent assay techniques with reagents from Bio-Rad (France) were used to test the blood samples.

RESULTS

11,592 blood donors were tested for HIV and HBV surface antigens. The prevalence of HIV was 4.5% and the prevalence of HBV was 14.9%. The HIV/HBV coinfection rate was only 1.13% in this population.

CONCLUSION

The coinfection rate was unexpectedly low in this blood donor population where monoinfection with HIV or HBV prevalence was high.

Reconstitution of immune responses occurs very rapidly after initiation of therapy for tuberculosis (43.54)

Introduction: Immune reconstitution syndrome is a potentially fatal sequelae of HAART therapy in 20% of patients with HIV and 3–5% with tuberculosis who begin treatment. The role of CD4+T cells in its pathogenesis is poorly understood.

Methods: This study was done under an IRB approved protocol to study MTb specific immunity. Groups based on HIV status and local or disseminated MTb were evaluated for CD4+ T cell counts, Purified Protein Derivative (PPD) induced proliferation and cytokine induction using intracellular cytokine staining for IFN γ, IL2, TNFα and CFSE dilution at predefined times before and after starting therapy.

Results: In preliminary results, the first 3 HIV negative patients with MTb exhibited striking increase in MTb specific immunity in the first week of therapy. Percentage of IFN γ producing CD4+T cells increased from 1.96 and 0.48 to 4.46 and 1.34, and of TNF α producing cells increased from 0.85 and 0.45 to 3.96 and 1.06 in 2 patients. Proliferative responses also showed marked increases. Percent dividing cells increased from 4.3, 4.4 and 16.3 at baseline to 36.9, 11.9 and 39.6 at 1 week and 54.8 and 72.3 at 4 weeks of therapy. Total number of CD4+ T cells also increased.

Conclusions: Tuberculosis like HIV causes quantitative and qualitative changes in CD4+T cells . These are rapidly reversed when therapy is begun .This data provides insight into the pathogenesis of the immune reconstitution syndrome.