1-Chloro-2-formyl indenes and tetralenes as antitubercular agents

1-Chloro-2-formyl indenes and tetralenes have been synthesized using Vilsmeier-Haack-Arnold reaction onto indanones and tetralones. Most of these analogues exhibited antitubercular activity against Mycobacterium tuberculosis H37Rv strain with MICs ranging from 30 to 500 μg/mL. Analogue 13 was further modified to some derivatives. The most active analogue 23 showing MIC at 30 μg/mL was further evaluated for acute oral toxicity in Swiss albino mice and was found to be safe up to 300 mg/kg dose.     

Bacterial Pu(V) reduction in the absence and presence of Fe(III)–NTA: modeling and experimental approach

Plutonium (Pu), a key contaminant at sites associated with the manufacture of nuclear weapons and with nuclear-energy wastes, can be precipitated to “immobilized” plutonium phases in systems that promote bioreduction. Ferric iron (Fe³⁺) is often present in contaminated sites, and its bioreduction to ferrous iron (Fe²⁺) may be involved in the reduction of Pu to forms that precipitate. Alternately, Pu can be reduced directly by the bacteria. Besides Fe, contaminated sites often contain strong complexing ligands, such as nitrilotriacetic acid (NTA). We used biogeochemical modeling to interpret the experimental fate of Pu in the absence and presence of ferric iron (Fe³⁺) and NTA under anaerobic conditions. In all cases, Shewanella alga BrY (S. alga) reduced Pu(V)(PuO₂ ⁺) to Pu(III), and experimental evidence indicates that Pu(III) precipitated as PuPO_4(am). In the absence of Fe³⁺ and NTA, reduction of PuO₂ ⁺ was directly biotic, but modeling simulations support that PuO₂ ⁺ reduction in the presence of Fe³⁺ and NTA was due to an abiotic stepwise reduction of PuO₂ ⁺ to Pu⁴⁺, followed by reduction of Pu⁴⁺ to Pu³⁺, both through biogenically produced Fe²⁺. This means that PuO₂ ⁺ reduction was slowed by first having Fe³⁺ reduced to Fe²⁺. Modeling results also show that the degree of PuPO_4(am) precipitation depends on the NTA concentration. While precipitation out-competes complexation when NTA is present at the same or lower concentration than Pu, excess NTA can prevent precipitation of PuPO_4(am).     

The Inner Foreskin of Healthy Males at Risk of HIV Infection Harbors Epithelial CD4+ CCR5+ Cells and Has Features of an Inflamed Epidermal Barrier

Male circumcision provides partial protection against multiple sexually transmitted infections (STIs), including HIV, but the mechanisms are not fully understood. To examine potential vulnerabilities in foreskin epithelial structure, we used Wilcoxon paired tests adjusted using the false discovery rate method to compare inner and outer foreskin samples from 20 healthy, sexually active Peruvian males who have sex with males or transgender females, ages 21–29, at elevated risk of HIV infection. No evidence of epithelial microtrauma was identified, as assessed by keratinocyte activation, fibronectin deposition, or parakeratosis. However, multiple suprabasal tight junction differences were identified: 1) inner foreskin stratum corneum was thinner than outer (p = 0.035); 2) claudin 1 had extended membrane-bound localization throughout inner epidermis stratum spinosum (p = 0.035); 3) membrane-bound claudin 4 was absent from inner foreskin stratum granulosum (p = 0.035); and 4) occludin had increased membrane deposition in inner foreskin stratum granulosum (p = 0.042) versus outer. Together, this suggests subclinical inflammation and paracellular transport modifications to the inner foreskin. A setting of inflammation was further supported by inner foreskin epithelial explant cultures secreting higher levels of GM-CSF (p = 0.029), IP-10 (p = 0.035) and RANTES (p = 0.022) than outer foreskin, and also containing an increased density of CCR5+ and CD4+ CCR5+ cells (p = 0.022). Inner foreskin dermis also secreted more RANTES than outer (p = 0.036), and had increased density of CCR5+ cells (p = 0.022). In conclusion, subclinical changes to the inner foreskin of sexually active males may support an inflammatory state, with availability of target cells for HIV infection and modifications to epidermal barriers, potentially explaining the benefits of circumcision for STI prevention.     

Cytokine and protein markers of leprosy reactions in skin and nerves: baseline results for the North Indian INFIR cohort

Background

Previous studies investigating the role of cytokines in the pathogenesis of leprosy have either been on only small numbers of patients or have not combined clinical and histological data. The INFIR Cohort study is a prospective study of 303 new multibacillary leprosy patients to identify risk factors for reaction and nerve damage. This study characterised the cellular infiltrate in skin and nerve biopsies using light microscopic and immunohistochemical techniques to identify any association of cytokine markers, nerve and cell markers with leprosy reactions.

Methodology/Principal Findings

TNF-α, TGF-β and iNOS protein in skin and nerve biopsies were detected using monoclonal antibody detection immunohistochemistry techniques in 299 skin biopsies and 68 nerve biopsies taken from patients at recruitment. The tissues were stained with hematoxylin and eosin, modified Fite Faraco, CD68 macrophage cell marker and S100.

Conclusions/Significance

Histological analysis of the biopsies showed that 43% had borderline tuberculoid (BT) leprosy, 27% borderline lepromatous leprosy, 9% lepromatous leprosy, 13% indeterminate leprosy types and 7% had no inflammation. Forty-six percent had histological evidence of a Type 1 Reaction (T1R) and 10% of Erythema Nodosum Leprosum. TNF-α was detected in 78% of skin biopsies (181/232), iNOS in 78% and TGF-β in 94%. All three molecules were detected at higher levels in patients with BT leprosy. TNF-α was localised within macrophages and epithelioid cells in the granuloma, in the epidermis and in dermal nerves in a few cases. TNF-α, iNOS and TGF-β were all significantly associated with T1R (p<0.001). Sixty-eight nerve biopsies were analysed. CD68, TNF-α and iNOS staining were detectable in 88%, 38% and 28% of the biopsies respectively. The three cytokines TNF-α, iNOS and TGF-β detected by immunohistochemistry showed a significant association with the presence of skin reaction. This study is the first to demonstrate an association of iNOS and TGF-β with T1R.     

Modulating pharmacokinetics, tumor uptake and biodistribution by engineered nanoparticles

BACKGROUND: Inorganic nanoparticles provide promising tools for biomedical applications including detection, diagnosis and therapy. While surface properties such as charge are expected to play an important role in their in vivo behavior, very little is known how the surface chemistry of nanoparticles influences their pharmacokinetics, tumor uptake, and biodistribution. METHOD/PRINCIPAL FINDINGS: Using a family of structurally homologous nanoparticles we have investigated how pharmacological properties including tumor uptake and biodistribution are influenced by surface charge using neutral (TEGOH), zwitterionic (Tzwit), negative (TCOOH) and positive (TTMA) nanoparticles. Nanoparticles were injected into mice (normal and athymic) either in the tail vein or into the peritoneum. CONCLUSION: Neutral and zwitterionic nanoparticles demonstrated longer circulation time via both i.p. and i.v. administration, whereas negatively and positively charged nanoparticles possessed relatively short half-lives. These pharmacological characteristics were reflected on the tumor uptake and biodistribution of the respective nanoparticles, with enhanced tumor uptake by neutral and zwitterionic nanoparticles via passive targeting.     

Identification of second arginine‐glycine‐aspartic acid motif of ovine vitronectin as the complement C9 binding site and its implication in bacterial infection

Vitronectin (Vn), a multifunctional protein of blood and extracellular matrix, interacts with complement C9. This interaction may modulate innate immunity. Details of Vn–C9 interactions are limited. Vn–C9 interactions were assessed by employing a goat homologous system and observing Vn binding to C9 in three different assays. Using recombinant fragments, C9 binding was mapped to the N‐terminus of Vn. Site directed mutagenesis was performed to alter the second arginine glycine aspartic acid (RGD) sequence (RGD‐2) of Vn. Changing R to G or D to A in RGD‐2 caused significant decrease in Vn binding to C9 whereas changing of R to G in the first RGD motif (RGD‐1) had no effect on Vn binding to C9. These results imply that the RGD‐2 of goat Vn is involved in C9 binding. In a competitive binding assay, the presence of soluble RGD peptide inhibited Vn binding to C9 whereas heparin had no effect. Vn binding to C9 was also evaluated in terms of bacterial pathogenesis. Serum dependent inhibition of Escherichia coli growth was significantly reverted when Vn or its N‐fragment were included in the assay. The C‐fragment, which did not support C9 binding, also partly nullified serum‐dependent inhibition of bacterial growth, probably through other serum component(s).     

Discovery of 2-oxopiperazine dengue inhibitors by scaffold morphing of a phenotypic high-throughput screening hit

A series of 2-oxopiperazine derivatives were designed from the pyrrolopiperazinone cell-based screening hit 4 as a dengue virus inhibitor. Systematic investigation of the structure-activity relationship (SAR) around the piperazinone ring led to the identification of compound (S)-29, which exhibited potent anti-dengue activity in the cell-based assay across all four dengue serotypes with EC₅₀ < 0.1 μM. Cross-resistant analysis confirmed that the virus NS4B protein remained the target of the new oxopiperazine analogs obtained via scaffold morphing from the HTS hit 4.