Multiple Mechanisms in Proton-Induced Nucleon Removal at ∼100 MeV/Nucleon

We report on the first proton-induced single proton- and neutron-removal reactions from the neutron-deficient ^{14}O nucleus with large Fermi-surface asymmetry S_{n}-S_{p}=18.6  MeV at ∼100  MeV/nucleon, a widely used energy regime for rare-isotope studies. The measured inclusive cross sections and parallel momentum distributions of the ^{13}N and ^{13}O residues are compared to the state-of-the-art reaction models, with nuclear structure inputs from many-body shell-model calculations. Our results provide the first quantitative contributions of multiple reaction mechanisms including the quasifree knockout, inelastic scattering, and nucleon transfer processes. It is shown that the inelastic scattering and nucleon transfer, usually neglected at such energy regime, contribute about 50% and 30% to the loosely bound proton and deeply bound neutron removal, respectively. These multiple reaction mechanisms should be considered in analyses of inclusive one-nucleon removal cross sections measured at intermediate energies for quantitative investigation of single-particle strengths and correlations in atomic nuclei.

The HIV-1 viral synapse signals human foreskin keratinocytes to secrete thymic stromal lymphopoietin facilitating HIV-1 foreskin entry

The complexity of signal transduction resulting from the contact of human immunodeficiency virus type 1 (HIV-1)-infected cells and mucosal cells has hampered our comprehension of HIV-1 mucosal entry. Such process is driven efficiently only by viral synapse contacts, whereas cell-free HIV-1 remains poorly infectious. Using CD4⁺ T-cells expressing only HIV-1 envelope inoculated on human adult foreskin tissues, we designed methodologies to identify the signals transduced in foreskin keratinocytes following HIV-1-envelope-dependent viral synapse formation. We find that the viral synapse activates the MyD88-independent TLR-4-nuclear factor (NfκB) signaling pathway in keratinocytes and the subsequent secretion of cytokines including thymic stromal lymphopoietin (TSLP), a cytokine linking innate and T-helper type 2-adaptive immune responses. Moreover, the viral synapse upregulates the non-coding microRNA miR-375, known to control TSLP, and transfection of keratinocytes with anti-miR-375 blocks significantly TSLP secretion. Thus, the secretion of TSLP by keratinocytes is induced by the viral synapse in a miR-375 controlled manner. At the tissue level, these signals translate into the epidermal redistribution of Langerhans cells and formation of conjugates with T-cells, recapitulating the initial events observed in human foreskin infection by HIV-1. These results open new possibilities for designing strategies to block mucosal HIV-1 transmission, the major pathway by which HIV-1 spreads worldwide.

Virus like particle based strategy to elicit HIV-protective antibodies to the alpha-helic regions of gp41

Natural antibodies to gp41 inhibit HIV-1 replication through the recognition of two different regions, corresponding to the leucine zipper motif in the HR1 alpha-helix and to another motif within HR2 region, hosting 2F5 and 4E10 epitope. This study aimed at reproducing such protective responses through VLP vaccination. Six regions covering the alpha-helical regions of gp41 were conjugated to the surface of AP205 phage-based VLPs. Once administered in mice via systemic or mucosal route, these immunogens elicited high titers of gp41-specific IgG. Immunogenicity and HIV infectivity reduction were obtained either with HR2 regions or with peptides where aminoacid strings were added to either the C-terminus or N-terminus of core epitope in HR1 region. Antibody-dependent cell cytotoxicity (ADCC) activity was induced by one of the HR2 epitopes only. These results may have relevant implications for the development of new vaccinal approaches against HIV infection.

Within 1 h, HIV-1 uses viral synapses to enter efficiently the inner, but not outer, foreskin mucosa and engages Langerhans-T cell conjugates

Although circumcision reduces male acquisition of human immunodeficiency virus type-1 (HIV-1) by 60%, the initial mechanisms of HIV-1 transmission at the foreskin remain elusive. We have established two novel and complementary models of the human adult foreskin epithelium, namely, ex vivo foreskin explants and in vitro reconstructed immunocompetent foreskins. In these models, efficient HIV-1 transmission occurs after 1 h of polarized exposure of the inner, but not outer, foreskin to mononuclear cells highly infected with HIV-1, but not to cell-free virus. HIV-1-infected cells form viral synapses with apical foreskin keratinocytes, leading to polarized budding of HIV-1, which is rapidly internalized by Langerhans cells (LCs) in the inner foreskin. In turn, LCs migrate toward the epidermis-dermis interface to form conjugates with T cells, thereby transferring HIV-1. Seminal plasma mixed with cervicovaginal secretions inhibits HIV-1 translocation. This set of results rationalizes at the cellular level the apparent protective outcome of circumcision against HIV-1 acquisition by men.

HIV-1 gp41-specific monoclonal mucosal IgAs derived from highly exposed but IgG-seronegative individuals block HIV-1 epithelial transcytosis and neutralize CD4(+) cell infection: an IgA gene and functional analysis

AIDS is mainly a sexually transmitted disease, and accordingly, mucosal tissues are the primary sites of natural human immunodeficiency virus type-1 (HIV-1) transmission. Mucosal immunoglobulin A (IgA) antibody specific for HIV-1 envelope gp41 subunit is one correlate of protection in individuals who are highly sexually exposed to HIV-1 but remain persistently IgG seronegative (HEPS). Understanding these peculiar IgAs at the gene and functional level is possible only with monoclonal IgAs. We have constructed a mucosal Fab IgA library from HEPS and have characterized a series of HIV-1 IgAs specific for gp41 that, in vitro, are transcytosis-blocking and infection-neutralizing. Characterization of their IgA genes shows that Fab specific for the gp41 membrane-proximal region harbors a long heavy-chain CDR3 loop (CDRH3) similar to the two broadly neutralizing IgG monoclonal antibodies, 2F5 and 4E10. Furthermore, the selected Fab IgA shows extensive somatic mutations that cluster in the CDR regions, indicating that affinity maturation due to an antigen-driven process had occurred in HEPS individuals, presumably upon multiple exposures to HIV. This analysis of HEPS monoclonal IgA gives a unique opportunity to correlate an antibody function (resistance to a pathogen in vivo) with an antibody gene. Such neutralizing monoclonal IgAs could be used in microbicide formulation.

The in vitro behaviour and patterns of colony formation of murine epithelial stem cells

OBJECTIVE

The mechanisms of renewal of skin and mucosal epithelia in vivo are associated with hierarchies of stem and amplifying cells organized in distinct spatial patterns. Stem and amplifying characteristics persist after isolation and growth of human keratinocytes in vitro but the pattern for murine keratinocytes has been less clear.

MATERIALS AND METHODS

Murine keratinocytes were grown in low calcium media and examined for their patterns of colony morphologies.

RESULTS

We consistently identified three types of colonies, one of which contains concentric zones of amplifying and differentiated cells surrounding a central zone of cells that have patterns of expression and behavioural characteristic of stem cells. This zonal organization facilitated analysis of stem cell formation and loss. Cells in the central stem cell zone undergo rapid symmetric divisions but expansion of this population is partially limited by their peripheral transition into amplifying cells. A striking feature of central zone cells is their enhanced apoptotic susceptibility and stem cell expansion limited by consistently high background rates of apoptosis. This occasionally reaches catastrophic levels with elimination of the entire central zone.

CONCLUSION

In vitro amplification of stem cells for the generation of engineered tissue has tended to focus on control of asymmetric division but these findings suggest that development of mechanisms protecting stem cells from apoptotic changes are also likely to be of particular value.

Assessment of the bioequivalence of two oxcarbazepine oral suspensions versus a film-coated tablet in healthy subjects

Oxcarbazepine (trileptal) oral suspension has been reformulated and a study was performed to compare the bioavailability after single doses and at steady state of the current and former oral suspension versus the marketed film-coated tablets and to compare the bioavailability of the current and former oral suspension. The results support the switch from the former oral suspension to the current oral suspension and also from both oral suspensions to the film-coated tablet and vice versa. The study was an open-label, single-center, 3-way crossover trial. Each treatment period consisted of a single dose of 600 mg oxcarbazepine on Day 1, 600 mg oxcarbazepine b.i.d. repeated administration from Day 4 up to including Day 7, and a final dose of 600 mg oxcarbazepine administered on the morning of Day 8. Blood samples were taken on Day 1, Day 7 and Day 8 (pre-dose). Plasma concentrations of the main metabolite of oxcarbazepine (MHD) were determined using a validated HPLC assay. The 2 oral suspensions were compared with the film-coated tablet as reference formulation under fasted conditions. Also the current oral suspension was compared with the former oral suspension. These comparisons were made using data following single dose administration and under steady state conditions. Plasma AUC for single dose and AUC(0-12h) at steady state and plasma Cmax, log-transformed (natural base) were used for the assessment of bioequivalence. The 90% confidence interval (CI) approach was used for testing bioequivalence. Bioequivalence was accepted if CI was contained within the region (0.8, 1.25). At steady state, both the former and the current oral suspensions showed bioequivalence with the film-coated tablet with respect to AUC and Cmax. The current oral suspension was also bioequivalent when compared to the former oral suspension with respect to AUC and Cmax. After single dose, the former oral suspension was bioequivalent when compared to the film-coated tablet with respect to both AUC and Cmax. However, the current oral suspension was bioequivalent to both the film-coated tablet and the former oral suspension with respect to AUC but not to Cmax.

Oxcarbazepine final market image tablet formulation bioequivalence study after single administration and at steady state in healthy subjects

A final market image (FMI) tablet formulation of oxcarbazepine was compared with the marketed formulation (current market formulation (CMF)) and with the clinical trial formulation (CTF) tablet used during clinical efficacy and safety studies. The goal of the study was to compare the bioavailability after single doses and at steady state of the FMI versus CMF and CTF as well. Additionally, the effect of food was evaluated on the final market formulation. The study was an open-label, single-center, 4-way crossover trial. Each treatment period consisted of a single dose of 600 mg OXC on Day 1. From Day 4 up to including Day 7, 600 mg b.i.d. were administered. A final dose of 600 mg was administered in the morning on Day 8. Blood samples were taken on Day 1 before and on Day 7 (predose) and on Day 8 (morning dose). Plasma concentrations of MHD (the main metabolite of OXC) were determined by using a validated HPLC assay. FMI as test formulation was compared with the CMF and CTF as reference formulations. FMI under fed conditions was also compared with FMI under fasting conditions. These comparisons were made using data following single-dose administration and steady state conditions. Plasma AUC for single dose or AUC(0-12h) for steady state, and plasma Cmax, log-transformed (natural base), were used for the assessment of bioequivalence. The 90% confidence interval (CI) approach was used for testing bioequivalence. Bioequivalence was accepted if the CI was contained within the region (0.8, 1.25). At steady state under fed conditions, tested formulation (FMI) was bioequivalent to CTF and with the reference marketed formulation (CMF) with regard to AUC and Cmax. After single dose under fed conditions, FMI and CTF were bioequivalent with regard to AUC and Cmax, and FMI and CMF were equivalent with regard to AUC but not Cmax. Food had no effect on the bioavailability of the FMI. These results clearly support the switch from the current market formulation (CMF) to the final market image tablet in the countries where Trileptal is or was already registered.

Type I IFN modulates the immune response induced by DNA vaccination to pseudorabies virus glycoprotein C

DNA vaccines have the capacity to induce strong Th1-biased immune responses that are of major importance to providing protection against intracellular pathogens. In the present study we have focused on the role played by type I IFN in immune responses induced after DNA vaccination. Mice lacking the IFNAR1 chain of the type I IFN receptor (IFNAR K/O mice) were immunized with a plasmid encoding glycoprotein C of pseudorabies virus (PRV-gC). After DNA vaccination, wild-type (WT) mice showed features characteristic of Th1 immune responses, such as high IgG2a:IgG1 anti-PRV Ab ratio and antigen-specific IFN-gamma production by spleen cells. In contrast, IFNAR K/O mice showed a significantly lower IgG2a:IgG1 Ab ratio and IFN-gamma production. In addition, the percentage of CD8(+) and B lymph-node cells expressing CD69 after PRV-gC DNA vaccination was lower in IFNAR K/O than in WT mice. These results support a major role played by type I IFN in shaping Th1 immune responses after DNA vaccination. Codelivery of plasmids encoding IL-12 and IL-18 along with the plasmid encoding PRV-gC restored Th1 responses in IFNAR K/O mice.

RAD in stable lung and heart/lung transplant recipients: safety, tolerability, pharmacokinetics, and impact of cystic fibrosis

BACKGROUND

RAD is a novel macrolide with potent immunosuppressive and antiproliferative activities. This study characterizes the safety, tolerability, and pharmacokinetics of two different single oral doses of RAD in stable lung and heart/lung transplant recipients with and without cystic fibrosis (CF).

METHODS

This was a Phase I, multicenter, randomized, double-blind, two-period, two-sequence, crossover study. Single doses of RAD capsules at doses of 0.035 mg/kg (2.5 mg maximum) or 0.10 mg/kg (7.5 mg maximum) were administered with cyclosporine (Neoral [cyclosporine, USP] modified), steroids, and azathioprine on Day 1. The alternate dose was administered on Day 16. Laboratory assessments, vital signs, and adverse events were recorded throughout the study. RAD pharmacokinetic profiles were assessed over a 7-day period following each dose. Steady-state cyclosporine (CsA) profiles were assessed at baseline and with each RAD dose; RAD and CsA trough concentrations were obtained throughout the study period.

RESULTS

Of the 20 patients randomized, 8 had CF and 12 did not. Single doses of RAD were safe and well tolerated. Headache was the most common side effect. RAD produced a mild, dose-dependent, reversible decrease in platelet and leukocyte counts. Cholesterol and triglycerides were minimally affected. At both doses, CF patients had significantly lower peak concentrations of RAD than did non-CF patients (p = 0.03); however, overall exposure (area under the curve/dose) was not different between the groups (p = 0.63). At the higher dose, there was a clinically minor under-proportionality in AUC, averaging -11%. Steady-state pharmacokinetics of CsA were not affected by RAD co-administration.RAD was safe and well tolerated by stable lung and heart/lung transplant recipients with and without CF. The presence of CF did not influence the extent of RAD exposure. Single doses of RAD did not affect the pharmacokinetics of CsA. Ongoing studies are assessing the long-term safety and efficacy of RAD in lung and heart/lung transplantation.

Articular cartilage superficial zone protein (SZP) is homologous to megakaryocyte stimulating factor precursor and Is a multifunctional proteoglycan with potential growth-promoting, cytoprotective, and lubricating properties in cartilage metabolism

We have performed cDNA sequencing and homology analyses to elucidate the complete amino acid composition for a superficial zone protein (SZP) from human and bovine cartilage which has previously been shown to be a proteoglycan specifically synthesized by chondrocytes located at the surface of bovine articular cartilage and also some synovial lining cells. The results of this study indicate that cartilage SZP is homologous with a glycoprotein first described as the precursor protein of a megakaryocyte stimulating factor (MSF). Sequence comparisons and analyses indicate that (i) the amino acid composition of SZP is highly conserved between bovine and human species, (ii) SZP contains structural motifs at the N- and C-termini which are similar to those found in vitronectin and which may impart cell-proliferative and matrix-binding properties to the molecule, and (iii) SZP contains large and small mucin-like repeat domains composed of the sequences KEPAPTTT/P (76-78 repeats) and XXTTTX (6-8 repeats), respectively, which occur within a large central region of approximately 940 amino acids. The mucin-like domains are likely to be substituted with O-linked oligosaccharides which would impart lubricating properties to SZP which in part accumulates at the articular cartilage-synovial fluid interface. Additionally, we have shown that interleukin-1 inhibits the biosynthesis of chondrocyte SZP, while TGF-beta and IGF-1 increase its biosynthesis, and that in pathological (osteoarthritic) human articular cartilage SZP mRNA can be expressed as an alternatively spliced variant lacking exons 4 and 5 which encode a potential heparin binding domain. The occurrence of different SZP alternative splice variants and the differential expression of SZP in the presence of cytokines and growth factors suggest that SZP may play an important cytoprotective role by preventing cellular adhesion to the articular cartilage surface in normal cartilage metabolism. Modifications to the structure of SZP, coupled with inhibition of SZP synthesis during inflammation, may account for the attachment and invasion of pannus observed in inflammatory joint diseases.

Can an antihistamine delay appearance of hay fever symptoms when given prior to pollen season?

Mizolastine is a new, nonsedating antihistamine providing satisfactory symptom relief in allergic conditions. The purpose of this study was to determine whether the onset of hay fever symptoms could be delayed in patients known to suffer seasonal allergic rhinoconjunctivitis symptoms if mizolastine was given before the pollen season. This double-blind study involved 342 patients, randomly allocated to once-daily 10 mg mizolastine (n = 115), once-daily 120 mg terfenadine (n = 116), or placebo (n = 111) groups. All patients started treatment on 1 May, before the onset of the grass pollen season. The prophylactic effect of test drugs was assessed on their ability to delay the time to the first hay fever crisis of the season, which was defined by the occurrence of one of the following events: use of rescue medication, study withdrawal because of treatment failure, or total diary symptom score over 18. Active treatments prolonged the time to the first crisis by approximately 1 week (mizolastine 55 days, terfenadine 57 days) in comparison with placebo (50 days) (survival curve analysis: Logrank test, P = 0.01; Wilcoxon test, P = 0.03). Tolerability was satisfactory and comparable between groups. Thus, mizolastine can be safely used to delay and to treat symptoms of seasonal allergic rhinitis.

Local treatment of pressure sores in the elderly: amino acid copolymer membrane versus hydrocolloid dressing

OBJECTIVE

To compare the clinical effectiveness and wound management properties of a copolymer membrane, Inerpan (Synthélabo), and a hydrocolloid dressing, Comfeel (Coloplast), in the treatment of decubitus ulcers in the elderly.

DESIGN

Open, randomized, multicentric French study, with two parallel groups of patients.

PATIENTS

168 in-patients aged more 65 years (mean age: 82 years) suffering from grade II to grade IV (in the Shea classification) pressure sores. TRIAL PERIOD: Either 8 weeks or until the ulcer healed, whichever occurred first.

MEASUREMENTS

In addition to a complete physical examination, patients were evaluated at baseline for nutritional status and risk factors. The wounds were described, their depth scored, and the areas traced at Weeks 0, 1, 2, 4, 6, and 8. The number of dressings used was recorded.

RESULTS

Thirty-one Inerpan-treated patients and 23 Comfeel-treated patients achieved healing (P = 0.089), with respective median healing times of 32 and 38 days. Healing times were compared using survival curves (in the whole population) adjusted for ulcer depth effect and showed a significant difference in favor of Inerpan (P = 0.044 and 0.014). Progress of healing (percentage of ulcer healed) was calculated in the two groups. Clinically assessed the treatment performance scored at the completion of the study showed better results with Inerpan (P < 0.05). Both groups were similar in terms of granulation/exudation scores, surrounding skin, and ease of care.

CONCLUSION

It is concluded that Inerpan is easy to use, safeguards the healing process, and is of particular value in the management of pressure sores.