Selective Targeting of Nanocarriers to Neutrophils and Monocytes

We previously identified and characterized cell-type selective binding peptides from random peptide phage display libraries. Here, we used one of these peptides (GGP) to target liposomal nanocarriers to leukocyte subsets. To profile the binding selectivity of GGP-coated liposomes to human blood cells, we performed flow cytometric analysis with whole anti-coagulated blood. It is shown that when liposomal nanocarriers present these peptides on their surface, they facilitated cell-type specific targeting of liposomes to neutrophils and monocytes in contrast to nontargeted liposomes. Our data suggest that engineering the appropriate number of targeting peptide ligands on the nanocarrier surface is a factor in cell-binding selectivity, as is dose. Increasing the peptide density on the surface of the liposomes from 250 to 500 molecules resulted in more binding to neutrophils and monocytes. Fluorescence confocal microscopy corroborated the flow cytometry data revealing that liposomes coated with targeting GGP peptides decorated the surface of targeting cells and facilitate cell uptake of payload as evidenced by nuclear localization of tracer. These data suggest that small peptides identified by phage display techniques can be used to target nanocarriers that potentially carry therapeutic or imaging agents to leukocyte subsets. This ability has important implications for diseases where neutrophils and monocytes play a major role such as arthritis, inflammatory bowel disease, chronic obstructive pulmonary disease, and glomerulonephritis.     

CRLX101 (formerly IT-101)-A Novel Nanopharmaceutical of Camptothecin in Clinical Development

CRLX101 (formerly IT-101) is a first-in-class nanopharmaceutical, currently in Phase 2a development, which has been developed by covalently conjugating camptothecin (CPT) to a linear, cyclodextrin-polyethylene glycol (CD-PEG) co-polymer that self-assembles into nanoparticles. As a nanometer-scale drug carrier system, the cyclodextrin polymeric nanoparticle technology, referred to as "CDP", has unique design features and capabilities. Specifically, CRLX101 preclinical and clinical data confirm that CDP can address not only solubility, formulation, toxicity, and pharmacokinetic challenges associated with administration of CPT, but more importantly, can impart unique biological properties that enhance CPT pharmacodynamics and efficacy.     

Factors Associated with Condom Use Among HIV Clients in Stable Relationships with Partners at Varying Risk for HIV in Uganda

In Africa, HIV infections occur mostly in stable relationships, yet little is known about the determinants of condom use in this context. We examined condom use among 272 coupled HIV clients in Uganda who had just screened for ART eligibility; 128 had an HIV-positive partner, 47 HIV-negative, and 97 a partner with unknown HIV status. Sixty-six percent reported unprotected sex with their partner over the past 6 months (57–70% across the three subgroups). Multiple variables among socioeconomic characteristics, physical health, social support, and psychosocial adjustment were correlated with condom use in bivariate analysis, but in multivariate analysis, condom use self-efficacy was the only predictor of condom use in the total sample and subgroups; church attendance and physical functioning were also predictors among unknown status couples. This analysis reveals high rates of unprotected sex among coupled HIV clients, regardless of partner’s HIV status, and suggests multiple targets for prevention.     

Bone loss during menopausal transition among southern Chinese women

Objectives

Estrogen deficiency during menopausal transition is associated with rapid bone loss. The purpose of this study was to examine the time of onset, the rate, and predictors of menopausal bone loss.

Study design

Prospective data were analyzed from 160 Chinese women between the ages of 45 to 55 years who participated in the Hong Kong Osteoporotic Study.

Main outcome measures

All participants were studied yearly for 4 years. Demographic information, menstrual status according to the Stages of Reproductive Aging Workshop (STRAW), and lifestyle habits were recorded as well as bone mineral density (BMD) measured every visit. Baseline follicular stimulating hormone, sex hormone binding globulin, parathyroid hormones, C-terminal telopeptides of type 1 collagen, estradiol and testosterone were also measured.

Results

There was no significant bone loss at the spine, femoral neck and total hip in premenopausal women. Maximal bone loss occurred within the STRAW stage −2 and −1. Age at menopause, baseline age, body weight and FSH were independent predictors of bone loss. Subjects in the lowest quartile of baseline body weight (<50 kg) lost bone 2 times faster at spine compared with those in the highest quartile (>61 kg). Subjects in the highest quartile of baseline FSH (>40 IU/l) lost bone 1.3–2.3 times faster at all 3 sites compared with those in the lowest quartile (<5.8 IU/l).

Conclusion

Strategies to retard bone loss should be stressed to middle aged women, especially those with lean body built or with early menopause, to prevent osteoporosis later on in life.     

Distribution of HLA-B alleles in a Ugandan HIV-infected adult population: NORA pharmacogenetic substudy of DART

Objectives To determine the frequencies of HLA‐B alleles in Ugandan patients in the NORA substudy of the DART trial and to compare HLA‐B allele frequencies in those with and without clinically diagnosed hypersensitivity reaction (HSR). Methods DNA‐based HLA‐B genotyping was used to determine HLA alleles in 247 participants who received abacavir, including all six participants (‘cases’) with clinically diagnosed abacavir HSR. Results The incidence of clinical abacavir HSR in this double‐blinded study was 2.0% (6/300) in the abacavir group. As HLA‐B*5701 was absent throughout the entire cohort, including the six HSR ‘cases’, an association could not be established between HLA‐B*5701 and clinically diagnosed abacavir HSR. No other HLA‐B*57 alleles were present among the six ‘cases’. HLA‐B*5703 was the most frequent HLA‐B*57 allele among the abacavir‐tolerant participants. Conclusion The rate of clinical HSR was low, which may reflect the expected 2–3% clinical false‐positive rate seen in previous double‐blind randomized studies. The presumption that these cases may be false‐positive abacavir HSR is supported by the fact that no HLA‐B*5701 alleles were found in the abacavir group. Implementation of prospective HLA‐B*5701 screening must be based on benefit/risk considerations within local practice. Clinical risk management remains paramount.     

Duration of efficacy of treatment of latent tuberculosis infection in HIV-infected adults.

BACKGROUND: Treatment of latent infection is needed to protect HIV-infected individuals against tuberculosis. A previous report addressed short-term efficacy of three regimens in HIV-infected adults. We now report on long-term efficacy of the study regimens. METHODS: Three daily self-administered regimens were compared in a randomized placebo-controlled trial in 2736 purified protein derivative (PPD)-positive and anergic HIV-infected adults. PPD-positive subjects were treated with isoniazid (INH) for 6 months (6H), INH plus rifampicin for 3 months (3HR), INH plus rifampicin and pyrazinamide for 3 months (3HRZ), or placebo for 6 months. Anergic subjects were randomized to 6H or placebo. RESULTS: 6H initially protected against tuberculosis in PPD-positive individuals; however, benefit was lost within the first year of treatment. Sustained benefit was observed in persons receiving 3HR and 3HRZ. In a Cox regression analysis, the adjusted relative risk for tuberculosis compared with placebo was 0.67 [95% confidence interval (CI), 0.42-1.07] for 6H, 0.49 (95% CI, 0.29-0.82) for 3HR, and 0.41 (95% CI, 0.22-0.76) for 3HRZ. When the rifampicin-containing regimens were combined, the adjusted relative risk for tuberculosis compared with placebo was 0.46 (95% CI, 0.29-0.71). Among anergic subjects, a modest degree of protection with 6H was present (adjusted relative risk, 0.61; 95% CI, 0.32-1.16). Treatment of latent tuberculosis infection had no effect on mortality. CONCLUSION: Six months of INH provided short-term protection against tuberculosis in PPD-positive HIV-infected adults. Three month regimens including INH plus rifampicin or INH, rifampicin and pyrazinamide provided sustained protection for up to 3 years.     

Cytochrome P450 2B6 (CYP2B6) G516T influences nevirapine plasma concentrations in HIV-infected patients in Uganda

OBJECTIVES: Polymorphisms in the cytochrome P450 (CYP) 2B6 gene have been shown to influence nevirapine plasma concentrations in HIV-infected European Caucasians. Although nevirapine is used extensively in Africa, the influence of CYP2B6 genotype on nevirapine exposure has not been assessed in this population. We aimed to determine the influence of CYP2B6 genotype at position 516 on nevirapine trough concentrations in HIV-infected patients in Kampala, Uganda. Additional polymorphisms in the CYP and multidrug resistance protein-1 (MDR-1) genes were also assessed for their impact on nevirapine concentrations. METHODS: The following genotypes were determined in all subjects using polymerase chain reaction-restriction fragment length polymorphism: CYP2B6 G516T, MDR-1 C3435T and G2677T, CYP3A4(*)1B and CYP3A5(*)3. Nevirapine plasma concentrations were determined using high-performance liquid chromatography in 23 HIV-infected patients who were generally healthy and had been taking nevirapine 200 mg twice daily for at least 14 days. Analysis of variance with post hoc testing was used to compare nevirapine concentrations among CYP2B6 genotype groups. RESULTS: The median nevirapine trough concentration in individuals homozygous for the variant allele (TT) was 7607 ng/mL vs 4181 and 5559 ng/mL for GG and GT individuals, respectively (GG vs TT median ratio=1.82; P=0.011). The mean ratio for TT vs GG individuals (95% confidence interval) was 1.51 (1.18, 1.84). No associations were observed between the other polymorphisms studied and nevirapine concentrations. CONCLUSIONS: CYP2B6 G516T significantly influenced nevirapine trough concentrations in HIV-infected patients in Uganda. Additional studies in larger patient populations are necessary to further define the potential clinical impact of these preliminary findings.     

Respiratory syncytial virus infection: denominator-based studies in Indonesia, Mozambique, Nigeria and South Africa

OBJECTIVE: To assess the burden of respiratory syncytial virus (RSV)-associated lower respiratory infections (LRI) in children in four developing countries. METHODS: A WHO protocol for prospective population-based surveillance of acute respiratory infections in children aged less than 5 years was used at sites in Indonesia, Mozambique, Nigeria and South Africa. RSV antigen was identified by enzyme-linked immunosorbent assay performed on nasopharyngeal specimens from children meeting clinical case definitions. FINDINGS: Among children aged < 5 years, the incidence of RSV-associated LRI per 1000 child-years was 34 in Indonesia and 94 in Nigeria. The incidence of RSV-associated severe LRI per 1000 child-years was 5 in Mozambique, 10 in Indonesia, and 9 in South Africa. At all study sites, the majority of RSV cases occurred in infants. CONCLUSION: These studies demonstrate that RSV contributes to a substantial but quite variable burden of LRI in children aged < 5 years in four developing countries. The possible explanations for this variation include social factors, such as family size and patterns of seeking health care; the proportion of children infected by human immunodeficiency syndrome (HIV); and differences in clinical definitions used for obtaining samples. The age distribution of cases indicates the need for an RSV vaccine that can protect children early in life.     

Immune status of physically active women during lactation

PURPOSE: The purpose of this study was to provide baseline data on immune status of exercising and sedentary exclusively lactating women. Dietary intake and body composition were also investigated to determine whether they related to immune function. METHODS: Healthy, exclusively breastfeeding women with a body mass index between 20 and 30 kg x m were studied at 3 months postpartum. Participants in the exercise group (EG; N = 27) exercised aerobically at least 30 min x d, 3x wk, and women in the sedentary group (SG; N = 23) exercised once a week or less during the previous 6 wk. Immune status while at rest was determined by measuring: 1) a complete blood cell count and differential leukocyte count; 2) percentages and absolute counts of peripheral blood T cells (CD3+), cytotoxic T cells (CD3+CD8+), helper T cells (CD3+CD4+), B cells (CD19+), and natural killer cells (CD56+); 3) neutrophil bacterial killing and oxidative burst activity; and 4) in vitro mitogenic responsiveness of lymphocytes. Cardiorespiratory fitness, body composition, and dietary intake were also measured. RESULTS: Participants in the EG had a significantly higher level of mean predicted cardiorespiratory fitness than women in the SG (39.5 +/- 1.1 vs 32.5 +/- 1.0 mL O2 x min x kg; P < 0.05); however, there were no significant differences in body composition or dietary intake. There were no significant differences in any of the indicators of immune status between groups. In addition, there were no significant relationships between body composition or dietary intake and immune status. CONCLUSIONS: The results of this study suggest that women may exercise moderately during lactation and increase their fitness level without impairing their immune function.