Structure and biological activity of pathogen-like synthetic nanomedicines

Here we characterize the structure, stability and intracellular mode of action of DermaVir nanomedicine that is under clinical development for the treatment of HIV/AIDS. This nanomedicine comprises pathogen-like pDNA/PEIm nanoparticles (NPs) having the structure and function resembling spherical viruses that naturally evolved to deliver nucleic acids to the cells. Atomic force microscopy demonstrated spherical 100 - 200 nm NPs with a smooth polymer surface protecting the pDNA in the core. Optical absorption determined both the NP structural stability and biological activity relevant to their ability to escape from the endosome and release the pDNA at the nucleus. Salt, pH and temperature influence nanomedicine shelf-life and intracellular stability. This approach facilitates the development of diverse polyplex nanomedicines where the delivered pDNA-expressed antigens induce immune responses to kill infected cells. FROM THE CLINICAL EDITOR: The authors investigated DermaVir nanomedicine comprised of pathogen-like pDNA/PEIm nanoparticles with structure and function resembling spherical viruses. DermaVir delivery of pDNA expresses antigens that induce immune responses to kill HIV infected cells.     

Natural human antibody responses to Plasmodium vivax apical membrane antigen 1 under low transmission and unstable malaria conditions in Sri Lanka

Plasmodium vivax apical membrane antigen 1, an important malaria vaccine candidate, was immunogenic during natural malaria infections in Sri Lanka, where low transmission and unstable malaria conditions prevail. Antibody prevalence increased with exposure in areas where malaria was or was not endemic. A marked isotype switch to cytophilic (immunoglobulin G1 [IgG1]/IgG3) antibodies was evident with increasing exposure exclusively in residents from areas of endemicity.     

Naturally occurring benzoic acid derivatives retard cancer cell growth by inhibiting histone deacetylases (HDAC)

Histone deacetylases (HDACs), which modulate the expression of genes, are potential therapeutic targets in several cancers. Targeted inhibition of HDAC prevents the expression of oncogenes thereby help in the treatment of cancers. Hence, several pharmaceutical companies developed inhibitors of HDAC and tested them in preclinical models and in clinical trials. SAHA (suberanilohydroxamic acid) is one such HDAC inhibitor developed for treating breast and colorectal carcinomas. However, due to poor efficacy in clinical trials the utility of SAHA for treating cancers was discouraged. Similarly another HDAC inhibitor Trichostatin-A (TSA) also showed promising results in clinical trials but exhibited severe adverse effects, which dampened the interest of using this molecule for cancer treatment. Therefore, search for developing a potent HDAC inhibitor with minimal side effects still continues. Hence, in this study we have screened benzoic acid and benzoic acid derivatives with hydroxylic (-OH) groups and methoxy (-OCH3) groups for their efficacy to bind to the TSA binding site of HDAC using molecular docking studies. Molecules that showed much stronger affinity (than TSA) to HDAC were tested for inhibiting HDAC expressing cultured cancer cells. DHBA but not Dimethoxy Benzoic Acid (DMBA) inhibited HDAC activity, leading to cancer cell growth inhibition through the induction of ROS and cellular apoptosis mediated by Caspase-3. In addition, DHBA arrested cells in G2/M phase of the cell cycle and elevated the levels of sub-G0-G1 cell population. In summary, results of this study report that DHBA could be a strong HDAC inhibitor and inhibit cancer cell growth more effectively.     

Ileostomy-Associated Chronic Papillomatous Dermatitis Showing Nevus Sebaceous-Like Hyperplasia, HPV 16 Infection, and Lymphedema: A Case Report and Literature Review of Ostomy-Associated Reactive Epidermal Hyperplasias

ABSTRACT:: Chronic papillomatous dermatitis (CPD) is a stoma site complication due to chronic irritant contact dermatitis. Papillomatosis can also arise in the setting of Human Papillomavirus (HPV) infection or chronic lymphedema (elephantiasis). Herein, we report the case of a 57-year-old female who presented with a papillomatous growth surrounding a loop ileostomy suspected to be recurrent ovarian serous carcinoma. Excisional biopsy demonstrated nevus sebaceous (NS)-like organoid hyperplasia with koilocytes overlying a dermal scar that exhibited lymphangiectases. Polymerase chain reaction and sequencing for HPV DNA detected HPV 16. In situ hybridization for high-risk HPV DNA showed punctate nuclear pattern in the keratinocytes populating the NS-like hyperplasia indicating integrated HPV 16 DNA. No recurrence has been observed 11 months postexcision. Reports of CPD have documented a spectrum of reactive epidermal hyperplasias including pseudoepitheliomatous, verrucous, papillomatous, syringofibroadenomatous, and rudimentary follicular hyperplasias. HPV DNA has been detected in 3 of 4 CDP cases tested to date and in authentic NS. We postulate that localized lymphedema secondary to scarring coupled with chronic epidermal irritation and inflammation allowed for latent HPV infection to manifest as CPD with NS-like cutaneous hyperplasia.     

Circumscribed cicatricial alopecia due to localized sarcoidal granulomas and single‐organ granulomatous arteritis: a case report and systematic review of sarcoidal vasculitis

Vasculitis associated with sarcoid granulomas is an uncommon phenomenon. A 72‐year‐old female presented with an expanding region of circumscribed alopecia and scalp atrophy of 2 months duration. Biopsy showed non‐caseating granulomas, dermal thinning, loss of follicles, fibrosis and muscular vessels disrupted by mixed lymphocyte, macrophage and giant‐cell infiltrates. Affected vessels had loss and fragmentation of the elastic lamina, fibrous replacement of their walls and luminal stenosis (endarteritis obliterans). Dermal and vascular advential intralymphatic granulomas and lymphangiectases were found by D2‐40 expression, suggesting lymphatic obstruction and poor antigen clearance. No evidence of a post‐zoster eruption, systemic sarcoidosis or systemic giant‐cell arteritis was found. Two years later, prednisone had halted – but not reversed – progression of her alopecia. Review of the literature showed two types of vasculitis associated with sarcoid granulomas: (i) acute, self‐limited leukocytoclastic vasculitis and (ii) chronic granulomatous vasculitis (GV). Persistence of non‐degradable material or antigen contributes to the pathogenesis of granulomatous inflammation. In this case, lymphatic obstruction probably impeded clearance of nonimmunologic and/or immunologic stimuli permitting and sustaining the development of sarcoid granulomas and sarcoid GV, ultimately causing scarring alopecia and cutaneous atrophy.