Anti-Pathogenic Properties of the Combination of a T3SS Inhibitory Halogenated Pyrrolidone with C-30 Furanone

Antimicrobial resistance is one of the current public health challenges to be solved. The World Health Organization (WHO) has urgently called for the development of strategies to expand the increasingly limited antimicrobial arsenal. The development of anti-virulence therapies is a viable option to counteract bacterial infections with the possibility of reducing the generation of resistance. Here we report on the chemical structures of pyrrolidones DEXT 1–4 (previously identified as furan derivatives) and their anti-virulence activity on Pseudomonas aeruginosa strains. DEXT 1–4 were shown to inhibit biofilm formation, swarming motility, and secretion of ExoU and ExoT effector proteins. Also, the anti-pathogenic property of DEXT-3 alone or in combination with furanone C-30 (quorum sensing inhibitor) or MBX-1641 (type III secretion system inhibitor) was analyzed in a model of necrosis induced by P. aeruginosa PA14. All treatments reduced necrosis; however, only the combination of C-30 50 µM with DEXT-3 100 µM showed significant inhibition of bacterial growth in the inoculation area and systemic dispersion. In conclusion, pyrrolidones DEXT 1–4 are chemical structures capable of reducing the pathogenicity of P. aeruginosa and with the potential for the development of anti-virulence combination therapies.

Foetal virilisation caused by overproduction of non-aromatisable 11-oxygenated C19 steroids in maternal adrenal tumour

It is widely believed that adrenal tumours and ovarian luteomas in pregnant women cause virilisation of female foetuses through overproduction of testosterone and/or androstenedione. However, this notion raises a fundamental question as to how these classic androgens pass through the placenta without being converted by aromatase into oestrogens. Here, we report a case of maternal adrenal tumour, in which overproduction of 11-oxygenated C19 steroids (11ox C19s), newly characterised non-aromatisable androgens in humans, caused foetal virilisation. The female proband presented with severely virilised external genitalia at birth. The mother exhibited hirsutism, hyperglycaemia and hypertension and was diagnosed as having adrenal tumour. The mother was subjected to comprehensive steroid measurement. Serum levels of 11ox C19s were markedly elevated. In contrast, testosterone and androstenedione levels remained within the normal range, and levels of most other steroids in the conventional and backdoor androgenic pathways were normal or only mildly elevated. After tumour removal, levels of 11ox C19s were markedly reduced. These results provide the first evidence that 11ox C19s can be synthesised in adrenal adenomas and, due to their non-aromatisable nature, can pass through the placental barrier to cause foetal virilisation. These findings highlight a unique pathogenic property of these newly specified androgens in humans.

Pathophysiology and management of monoclonal gammopathy of renal significance

Recent years have witnessed a rapid growth in our understanding of the pathogenic property of monoclonal proteins. It is evident that some of these small monoclonal proteins are capable of inducing end-organ damage as a result of their intrinsic physicochemical properties. Hence, an umbrella term, monoclonal gammopathy of clinical significance (MGCS), has been coined to include myriad conditions attributed to these pathogenic proteins. Because kidneys are the most commonly affected organ (but skin, peripheral nerves, and heart can also be involved), we discuss MGRS exclusively in this review. Mechanisms of renal damage may involve direct or indirect effects. Renal biopsy is mandatory and demonstration of monoclonal immunoglobulin in kidney, along with the corresponding immunoglobulin in serum or urine, is key to establish the diagnosis. Pitfalls exist at each diagnostic step, and a high degree of clinical suspicion is required to diagnose MGRS. Recognition of MGRS by hematologists and nephrologists is important, because timely clone-directed therapy improves renal outcomes. Autologous stem cell transplant may benefit selected patients.