A new approach to prevent HIV transmission: Project Protect intervention for recently infected individuals

Past research suggests that as many as 50% of onward human immunodeficiency virus (HIV) transmissions occur during acute and recent HIV infection. It is clearly important to develop interventions which focus on this highly infectious stage of HIV infection to prevent further transmission in the risk networks of acutely and recently infected individuals. Project Protect tries to find recently and acutely infected individuals and prevents HIV transmission in their risk networks. Participants are recruited by community health outreach workers at community-based HIV testing sites and drug users' community venues, by coupon referrals and through referrals from AIDS clinics. When a network with acute/recent infection is identified, network members are interviewed about their risky behaviors, network information is collected, and blood is drawn for HIV testing. Participants are also educated and given prevention materials (condoms, syringes, educational materials); HIV-infected participants are referred to AIDS clinics and are assisted with access to care. Community alerts about elevated risk of HIV transmission are distributed within the risk networks of recently infected. Overall, 342 people were recruited to the project and screened for acute/recent HIV infection. Only six index cases of recent infection (2.3% of all people screened) were found through primary screening at voluntary counseling and testing (VCT) sites, but six cases of recent infection were found through contact tracing of these recently infected participants (7% of network members who came to the interview). Combining screening at VCT sites and contact tracing the number of recently infected people we located as compared to VCT screening alone. No adverse events were encountered. These first results provide evidence for the theory behind the intervention, i.e., in the risk networks of recently infected people there are other people with recent HIV infection and they can be successfully located without increasing stigma for project participants.     

Epitope mapping and biological function analysis of antibodies produced by immunization of mice with an inactivated Chinese isolate of severe acute respiratory syndrome-associated coronavirus (SARS-CoV)

Inactivated severe acute respiratory syndrome-associated coronavirus (SARS-CoV) has been tested as a candidate vaccine against the re-emergence of SARS. In order to understand the efficacy and safety of this approach, it is important to know the antibody specificities generated with inactivated SARS-CoV. In the current study, a panel of twelve monoclonal antibodies (mAbs) was established by immunizing Balb/c mice with the inactivated BJ01 strain of SARS-CoV isolated from the lung tissue of a SARS-infected Chinese patient. These mAbs could recognize SARS-CoV-infected cells by immunofluorescence analysis (IFA). Seven of them were mapped to the specific segments of recombinant spike (S) protein: six on S1 subunit (aa 12-798) and one on S2 subunit (aa 797-1192). High neutralizing titers against SARS-CoV were detected with two mAbs (1A5 and 2C5) targeting at a subdomain of S protein (aa 310-535), consistent with the previous report that this segment of S protein contains the major neutralizing domain. Some of these S-specific mAbs were able to recognize cleaved products of S protein in SARS-CoV-infected Vero E6 cells. None of the remaining five mAbs could recognize either of the recombinant S, N, M, or E antigens by ELISA. This study demonstrated that the inactivated SARS-CoV was able to preserve the immunogenicity of S protein including its major neutralizing domain. The relative ease with which these mAbs were generated against SARS-CoV virions further supports that subunit vaccination with S constructs may also be able to protect animals and perhaps humans. It is somewhat unexpected that no N-specific mAbs were identified albeit anti-N IgG was easily identified in SARS-CoV-infected patients. The availability of this panel of mAbs also provided potentially useful agents with applications in therapy, diagnosis, and basic research of SARS-CoV.     

Selected Properties of Formaldehyde-Free Polymer-Straw Boards Made from Different Types of Thermoplastics and Different Kinds of Straw

This research investigated the effects of different thermoplastics types and different kinds of straw on selected properties of polymer-straw boards. Polyethylene, polyethylene, and polystyrene of virgin and of recycled origin were used for bonding the boards. Three kinds of straw were used: rape (Brassica napus L. var. napus), triticale (Triticosecale Witt b m.), and rye (Secale L.). Five-layer polymer-straw boards were produced. The obtained boards differed in both the materials they were made of and the moisture content (7, 25, and 2% for the core, the middle, and the face layers, respectively), and 30% of straw particles were substituted with thermoplastics added to the face layers. It was found that properties of polymer-straw boards strongly depend on both the kind of straw and the type of polymer used. The best mechanical properties were obtained for rye straw and polystyrene or recycled polymers, whereas the best hydrophobic properties were observed for rape straw combined with recycled polyethylene or polypropylene. Although recycled polymers improved the hydrophobic properties of the boards, they impaired their mechanical properties in comparison with the reference ones. However, in terms of bending strength, they still met the requirements for heavy duty load-bearing boards for use in humid conditions (20 MPa for P7 boards according to EN 312).     

Sex,drugs and prisons: HIV prevention strategies for over 190 000 clients in Ukraine

Setting: One hundred and forty non-governmental organisations implementing human immunodeficiency virus (HIV) prevention programmes among clients, including people who inject drugs, prisoners, female sex workers, men who have sex with men and street children in Ukraine, 2010–2011.Objective: Among enrolled clients, to assess factors associated with HIV testing, HIV retesting within a year of initial testing and HIV seroconversion.Design: Retrospective cohort study involving record reviews.Results: Of 192 487 clients, 42 109 (22%) underwent an initial HIV test (22% were positive). Among HIV-negative clients at baseline, 10 858 (27%) were retested within a year: 317 (3%) of these were HIV-positive. HIV testing and retesting rates were lower among prisoners (0.3%) and others (street children and partners of those in risk groups, 6%), and those who did not receive counselling or services such as condom and needle distribution. Individuals who were not counselled were more likely to seroconvert.Conclusions: In this large cohort of high-risk groups from Eastern Europe, HIV testing was low and HIV sero-conversion was high. This is of public health concern, bringing into question the overall quality of counselling and how well it is tailored to the specific needs of various risk groups. Qualitative studies to understand the reasons for non-testing are urgently required for designing client-specific interventions.     

Discovery of Marburg virus neutralizing antibodies from virus-naïve human antibody repertoires using large-scale structural predictions

Marburg virus (MARV) disease is lethal, with fatality rates up to 90%. Neutralizing antibodies (Abs) are promising drug candidates to prevent or treat the disease. Current efforts are focused in part on vaccine development to induce such MARV-neutralizing Abs. We analyzed the antibody repertoire from healthy unexposed and previously MARV-infected individuals to assess if naïve repertoires contain suitable precursor antibodies that could become neutralizing with a limited set of somatic mutations. We computationally searched the human Ab variable gene repertoire for predicted structural homologs of the neutralizing Ab MR78 that is specific to the receptor binding site (RBS) of MARV glycoprotein (GP). Eight Ab heavy-chain complementarity determining region 3 (HCDR3) loops from MARV-naïve individuals and one from a previously MARV-infected individual were selected for testing as HCDR3 loop chimeras on the MR78 Ab framework. Three of these chimerized antibodies bound to MARV GP. We then tested a full-length native Ab heavy chain encoding the same 17-residue-long HCDR3 loop that bound to the MARV GP the best among the chimeric Abs tested. Despite only 57% amino acid sequence identity, the Ab from a MARV-naïve donor recognized MARV GP and possessed neutralizing activity against the virus. Crystallization of both chimeric and full-length native heavy chain-containing Abs provided structural insights into the mechanism of binding for these types of Abs. Our work suggests that the MARV GP RBS is a promising candidate for epitope-focused vaccine design to induce neutralizing Abs against MARV.

With the advent of high-throughput immune repertoire sequencing, the number of available human antibody (Ab) sequences is exploding rapidly from thousands to billions. These datasets provide a resource for understanding the natural process of Ab maturation through somatic mutations, quick identification of novel functional Abs, and engineering of improved Abs. Ultimately, such Ab repertoires may provide or add templates for developing epitope-focused (1) and germline-targeting (2, 3) vaccines. While Ab function sometimes can be predicted from sequence homology, often Abs of very different sequence have the same function by virtue of adopting a similar structure. However, despite substantial progress in computational methods of modeling Abs (4, 5) and Ab–antigen interactions (6–10), and the use of high-performance computing, it is still beyond the available computational resources to predict and study the structure of billions of Abs one by one. Therefore, in order to take advantage of the rapidly increasing Ab sequence databases, it is essential to find more effective ways of relating Ab sequence to function.The recently proposed position-specific structure scoring matrix (P3SM) approach is a new computational method specifically designed for rapid screening of large Ab sequence libraries (11, 12). This approach aims to predict whether a given Ab sequence can adopt the desired 3D conformation and thus correctly place critical-for-activity functional groups. This prediction is based on modeling of a small subset of structures using Rosetta (13) followed by evaluation of the compatibility of each of 20 amino acids in each of the analyzed positions with the desired structure and function. The resulting P3SM then can be used for rapid screening of the remaining Ab sequences. The best-scoring candidate sequences are fed back into Rosetta for a detailed energetic analysis and prioritization for experimental validation.The human monoclonal Ab MR78 was isolated previously from a B cell in the peripheral blood of an otherwise healthy individual with a prior history of naturally acquired Marburg virus (MARV) infection (14). A crystal structure of MARV glycoprotein (GP) in complex with MR78 (Protein Data Bank [PDB] ID 5UQY) revealed that the Ab heavy-chain complementarity determining region 3 (HCDR3) contacts the receptor binding domain (RBD) on MARV GP that interacts with the natural receptor on human cells (Niemann–Pick disease, type C1 [NPC1] protein) (15). Here, we applied the P3SM approach to search for structurally homologous Abs to MR78 based on this Ab–antigen cocrystal structure.     

Initial human experience with the Amplatzer perimembranous ventricular septal occluder device.

Transcatheter closure of perimembranous ventricular septal defects with coils or devices designed to close other lesions may be complicated by embolization or aortic insufficiency. A new asymmetric Amplatzer perimembranous ventricular septal occluder and delivery system was specifically designed for perimembranous defects. This report describes the first use of this device in 27 patients. Implantation was successful in 25 (93%), with 1 removed for device-related aortic insufficiency and inability to position the delivery sheath in another. Device orientation was excellent when the device was initially advanced through a standard delivery sheath positioned in the left ventricular apex. Twenty-three had complete occlusion within 1 week (92%), with a tiny (< 2 mm) residual shunt in the other two. In the 25 subjects with the device left in place, device-related aortic or tricuspid insufficiency, arrhythmias, and embolization were not observed. These excellent acute results need to be confirmed by long-term follow-up.     

Dietary iodine intake in residents of northwestern regions of ukraine contaminated by the chernobyl accident

Daily iodine intake in Ukrainian subjects of northwestern regions was estimated in relation to the health effects on inhabitants after the Chernobyl accident. Total diets were collected from 106 locations for children and adult males by a duplicate portion study. Iodine was rapidly determined by inductively coupled plasma mass spectrometry after chemical separation. Iodine concentration on a dry basis for Ukrainians was 0.11 microg g(-1) and the daily iodine intake was in the range of 2.80-372 microg per person. The median, geometric mean, and standard deviation were 28.1, 32.7, and 2.51 microg, respectively. The yearly trend of the intake had almost no change. Regional differences would be expected to exist among the 10 areas of the Ukraine, but no clear differences appeared in the present findings. Daily iodine intake in Ukrainians was lower than the recommended dietary intake (RDI) allowance (150 microg), and its lack would be related to the high prevalence of goiter in the country.     

Interstitial guidance of cancer invasion

Cancer cell invasion into healthy tissues develops preferentially along pre-existing tracks of least resistance, followed by secondary tissue remodelling and destruction. The tissue scaffolds supporting or preventing guidance of invasion vary in structure and molecular composition between organs. In the brain, the guidance is provided by myelinated axons, astrocyte processes, and blood vessels which are used as invasion routes by glioma cells. In the human breast, containing interstitial collagen-rich connective tissue, disseminating breast cancer cells preferentially invade along bundled collagen fibrils and the surface of adipocytes. In both invasion types, physical guidance prompted by interfaces and space is complemented by molecular guidance. Generic mechanisms shared by most, if not all, tissues include (i) guidance by integrins towards fibrillar interstitial collagen and/or laminins and type IV collagen in basement membranes decorating vessels and adipocytes, and, likely, CD44 engaging with hyaluronan; (ii) haptotactic guidance by chemokines and growth factors; and likely (iii) physical pushing mechanisms. Tissue-specific, resticted guidance cues include ECM proteins with restricted expression (tenascins, lecticans), cell-cell interfaces, and newly secreted matrix molecules decorating ECM fibres (laminin-332, thrombospondin-1, osteopontin, periostin). We here review physical and molecular guidance mechanisms in interstitial tissue and brain parenchyma and explore shared principles and organ-specific differences, and their implications for experimental model design and therapeutic targeting of tumour cell invasion.     

Properties of Eco-Friendly Particleboards Bonded with Lignosulfonate-Urea-Formaldehyde Adhesives and pMDI as a Crosslinker

The purpose of this study was to evaluate the feasibility of using magnesium and sodium lignosulfonates (LS) in the production of particleboards, used pure and in mixtures with urea-formaldehyde (UF) resin. Polymeric 4,4′-diphenylmethane diisocyanate (pMDI) was used as a crosslinker. In order to evaluate the effect of gradual replacement of UF by magnesium lignosulfonate (MgLS) or sodium lignosulfonate (NaLS) on the physical and mechanical properties, boards were manufactured in the laboratory with LS content varying from 0% to 100%. The effect of LS on the pH of lignosulfonate-urea-formaldehyde (LS-UF) adhesive compositions was also investigated. It was found that LS can be effectively used to adjust the pH of uncured and cured LS-UF formulations. Particleboards bonded with LS-UF adhesive formulations, comprising up to 30% LS, exhibited similar properties when compared to boards bonded with UF adhesive. The replacement of UF by both LS types substantially deteriorated the water absorption and thickness swelling of boards. In general, NaLS-UF-bonded boards had a lower formaldehyde content (FC) than MgLS-UF and UF-bonded boards as control. It was observed that in the process of manufacturing boards using LS adhesives, increasing the proportion of pMDI in the adhesive composition can significantly improve the mechanical properties of the boards. Overall, the boards fabricated using pure UF adhesives exhibited much better mechanical properties than boards bonded with LS adhesives. Markedly, the boards based on LS adhesives were characterised by a much lower FC than the UF-bonded boards. In the LS-bonded boards, the FC is lower by 91.1% and 56.9%, respectively, compared to the UF-bonded boards. The boards bonded with LS and pMDI had a close-to-zero FC and reached the super E0 emission class (≤1.5 mg/100 g) that allows for defining the laboratory-manufactured particleboards as eco-friendly composites.