Chitosan-Coated Collagen Membranes Promote Chondrocyte Adhesion,Growth, and Interleukin-6 Secretion

Designing scaffolds made from natural polymers may be highly attractive for tissue engineering strategies. We sought to produce and characterize chitosan-coated collagen membranes and to assess their efficacy in promoting chondrocyte adhesion, growth, and cytokine secretion. Porous collagen membranes were placed in chitosan solutions then crosslinked with glutaraldehyde vapor. Fourier transform infrared (FTIR) analyses showed elevated absorption at 1655 cm⁻¹ of the carbon–nitrogen (N=C) bonds formed by the reaction between the (NH₂) of the chitosan and the (C=O) of the glutaraldehyde. A significant peak in the amide II region revealed a significant deacetylation of the chitosan. Scanning electron microscopy (SEM) images of the chitosan-coated membranes exhibited surface variations, with pore size ranging from 20 to 50 μm. X-ray photoelectron spectroscopy (XPS) revealed a decreased C–C groups and an increased C–N/C–O groups due to the reaction between the carbon from the collagen and the NH₂ from the chitosan. Increased rigidity of these membranes was also observed when comparing the chitosan-coated and uncoated membranes at dried conditions. However, under wet conditions, the chitosan coated collagen membranes showed lower rigidity as compared to dried conditions. Of great interest, the glutaraldehyde-crosslinked chitosan-coated collagen membranes promoted chondrocyte adhesion, growth, and interleukin (IL)-6 secretion. Overall results confirm the feasibility of using designed chitosan-coated collagen membranes in future applications, such as cartilage repair.     

Zoonotic filariasis in the Arabian Peninsula: autochthonous onchocerciasis and dirofilariasis

We describe zoonotic filariasis in two patients from Kuwait; one with Onchocerca spp. and one with Dirofilaria spp. Case 1, a 12-year-old Kuwaiti woman who had visited Saudi Arabia, initially reported ocular symptoms. She later reported a nodule that appeared in the suprapubic area, which was resected. A coiled worm was observed in histologic sections and was identified as an Onchocerca spp., but could not be definitively identified. This patient represents the 15th reported case of zoonotic onchocerciasis in a country that is not endemic for human onchocerciasis. Case 2, a 34-year-old Indian woman from Kuwait City, reported a moving object in her left eye. A live worm was extracted and tentatively identified as an immature female Dirofilaria (Nochtiella) repens. These two cases bring to four the number of reports of zoonotic filariasis in the Arabian Peninsula and suggest that zoonotic filariasis is not uncommon in the Arabian Gulf region.     

Partner Violence and Sexual HIV Risk Behaviors Among Women in Methadone Treatment

To examine associations between recent partner violence and sexual HIV risk behaviors and their implications for HIV prevention among women in methadone treatment, we conducted structured interviews covering demographics, drug use, trauma history, partner violence, and sexual risk behavior with 147 sexually active women who were at risk of HIV infection. Almost one third (30.5%) of the women reported that they had been physically or sexually abused by a spouse or boyfriend during the previous year. Multiple logistic regression analysis indicated that after adjusting for potential confounders, recently abused women were less likely to report using condoms (OR = 0.41, CI = 0.17, 0.99) and more likely than non-recently abused women to report having contracted a sexually transmitted disease (STD) (OR = 3.6, CI = 1.6, 8.5), exchanged sex for money (OR = 2.4, CI = 1.1, 5.4), and having had sex with an HIV-infected partner (OR = 2.5, CI = 1.0, 6.1). The study findings underscore the importance of developing HIV-risk reduction strategies that target the specific needs of abused women in drug treatment.     

Resveratrol rescues cAMP-dependent anionic transport in the cystic fibrosis pancreatic cell line CFPAC1

BACKGROUND AND PURPOSE

The cystic fibrosis transmembrane conductance regulator (CFTR) is a cAMP-dependent chloride channel in the plasma membrane of epithelia whose mutation is the cause of the genetic disease cystic fibrosis (CF). The most frequent CFTR mutation is deletion of Phe⁵⁰⁸ and this mutant protein (delF508CFTR) does not readily translocate to the plasma membrane and is rapidly degraded within the cell. We hypothesized that treating epithelial cells with resveratrol, a natural polyphenolic, phyto-ooestrogenic compound from grapes, could modulate both the expression and localization of CFTR.

EXPERIMENTAL APPROACH

Cells endogenously expressing CFTR (MDCK1 and CAPAN1 cells) or delF508CFTR (CFPAC1 and airway epithelial cells, deriving from human bronchial biopsies) were treated with resveratrol for 2 or 18 h. The effect of this treatment on CFTR and delF508CFTR expression and localization was evaluated using RT-PCR, Western blot and immunocytochemistry. Halide efflux was measured with a fluorescent dye and with halide-sensitive electrodes. Production of interleukin-8 by these cells was assayed by ELISA.

KEY RESULTS

Resveratrol treatment increased CFTR expression or maturation in immunoblotting experiments in MDCK1 cells or in CFPAC1 cells. Indirect immunofluorescence experiments showed a shift of delF508CFTR localization towards the (peri)-membrane area in CFPAC1 cells and in human airway epithelial cells. A cAMP-dependent increase in membrane permeability to halide was detected in resveratrol-treated CFPAC1 cells, and was inhibited by a selective inhibitor of CFTR.

CONCLUSION AND IMPLICATIONS

These results show that resveratrol modulated CFTR expression and localization and could rescue cAMP-dependent chloride transport in delF508CFTR cells.     

Expanding the space: inclusion of most-at-risk populations in HIV prevention, treatment, and care services

The provision of appropriate HIV prevention, treatment, and care services for most-at-risk populations (MARP) will challenge many health care systems. For people who sell sex or inject drugs and for men who have sex with men, stigma, discrimination, and criminalization can limit access to care, inhibit service uptake, and reduce the disclosure of risks. Several models for provision of HIV services to MARP may address these issues. We discuss integrated models, stand-alone services, and hybrid models, which may be appropriate for some MARP in some settings. Both public health and human rights frameworks concur that those at greatest risk should have expanded access to services.