A robust synthetic strategy for the introduction of the N-(4-azidobutyl) linker into peptides using standard SPPS techniques is described. Based on the example of Cilengitide it is shown that the N-(4-azidobutyl) group exerts similar conformational restraints as a backbone N-Me group and allows conjugation of a desired molecule either via click chemistry or-after azide reduction-via acylation or reductive alkylation.
View Article and Find Full Text PDFPipecolidepsin A is a head-to-side-chain cyclodepsipeptide isolated from the marine sponge Homophymia lamellosa. This compound shows relevant cytotoxic activity in three human tumour cell lines and has unique structural features, with an abundance of non-proteinogenic residues, including several intriguing amino acids. Although the moieties present in the structure show high synthetic difficulty, the cornerstone is constituted by the unprecedented and highly hindered γ-branched β-hydroxy-α-amino acid D-allo-(2R,3R,4R)-2-amino-3-hydroxy-4,5-dimethylhexanoic acid (AHDMHA) residue, placed at the branching ester position and surrounded by the four demanding residues L-(2S,3S,4R)-3,4-dimethylglutamine, (2R,3R,4S)-4,7-diamino-2,3-dihydroxy-7-oxoheptanoic acid, D-allo-Thr and L-pipecolic acid.
View Article and Find Full Text PDFHere we studied the N-triethylene glycol (N-TEG) group as a surrogate for the N-Me group in Sansalvamide A peptide. The five N-TEG and N-Me analogs of this cyclic pentapeptide were synthesized, and their biological activity, lipophilicity and conformational features were compared.
View Article and Find Full Text PDFUltrafine particles (UFP; aerodynamic diameter < 0.1 micrometers) are a ubiquitous exposure in the urban environment and are elevated near highways. Most epidemiological studies of UFP health effects use central site monitoring data, which may misclassify exposure.
View Article and Find Full Text PDFCurrent literature is insufficient to make causal inferences or establish dose-response relationships for traffic-related ultrafine particles (UFPs) and cardiovascular (CV) health. The Community Assessment of Freeway Exposure and Health (CAFEH) is a cross-sectional study of the relationship between UFP and biomarkers of CV risk. CAFEH uses a community-based participatory research framework that partners university researchers with community groups and residents.
View Article and Find Full Text PDFObjectives: The main goal of the study was to assess possible association between fetal exposure to fine particulate matter (PM2.5) and exhaled carbon monoxide (eCO) measured in non-asthmatic children.
Material And Methods: The subjects include 118 children taking part in an ongoing population-based birth cohort study in Kraków.
Here we evaluated the use of internal reference compounds for the rapid assessment of reactions performed in solid-phase. An internal reference compound (commercially available) was bound to the resin, together with the substrate, and cleaved with the products after completion of the reaction. The peak area of the reference compound in the HPLC-UV chromatograms can be correlated directly with those of other compounds present in the reaction mixture, thereby allowing a quantitative interpretation of the chromatograms with respect to conversion and yield.
View Article and Find Full Text PDFThe aircraft cabin represents a unique indoor environment due to its high surface-to-volume ratio, high occupant density, and the potential for high ozone concentrations at cruising altitudes. Ozone was continuously measured and air was sampled on sorbent traps, targeting carbonyl compounds, on 52 transcontinental U.S.
View Article and Find Full Text PDFBackground: Flame retardant chemicals are used in materials on airplanes to slow the propagation of fire. These chemicals migrate from their source products and can be found in the dust of airplanes, creating the potential for exposure.
Methods: To characterize exposure to flame retardant chemicals in airplane dust, we collected dust samples from locations inside 19 commercial airplanes parked overnight at airport gates.
New World hantaviruses can cause hantavirus cardiopulmonary syndrome with high mortality in humans. Distinct virus species are hosted by specific rodent reservoirs, which also serve as the vectors. Although regional spillover has been documented, it is unknown whether rodent reservoirs are competent for infection by hantaviruses that are geographically separated, and known to have related, but distinct rodent reservoir hosts.
View Article and Find Full Text PDFWe designed this community-based participatory research (CBPR) project aiming to generate evidence-based research results to encourage residents living in urban low-income public housing dwellings engaging in a community-wide integrated pest management (IPM) program with the intention to improve their health and quality of life, as well as household conditions. We enrolled 20 families and their children in this study in which we utilized environmental exposure assessment (surface wipe and indoor air) tools to quantitatively assessing residential pesticide exposure in young children before the implementation of an IPM program. We analyzed those samples for 19 organophosphate (OP) and pyrethroid pesticides.
View Article and Find Full Text PDFOver the last decades many epidemiologic studies considered the morbidity patterns for respiratory diseases and lung function of children in the context of ambient air pollution usually measured in the postnatal period. The main purpose of this study is to assess the impact of prenatal exposure to fine particulate matter (PM2.5) on the recurrent broncho-pulmonary infections in early childhood.
View Article and Find Full Text PDFJ Expo Sci Environ Epidemiol
March 2014
Exposure to high levels of traffic-generated particles may pose risks to human health; however, limited measurement has been conducted at homes near highways. The purpose of this study was to characterize differences between indoor and outdoor particle number concentration (PNC) in homes near to and distant from a highway and to identify factors that may affect infiltration. We monitored indoor and outdoor PNC (6-3000 nm) for 1-3 weeks at 18 homes located <1500 m from Interstate-93 (I-93) in Somerville, MA (USA).
View Article and Find Full Text PDFIn a birth cohort study, we have assessed the dose-response relationship between individual measurements of prenatal airborne polycyclic aromatic hydrocarbon (PAH) exposure and specific PAH-DNA adducts in cord blood adjusted for maternal blood adducts and season of birth. The study uses data from an earlier established birth cohort of children in Krakow. The final analysis included 362 pregnant women who gave birth to term babies and had complete data on personal exposure in the second trimester of pregnancy to eight airborne PAHs including benzo[a]pyrene (B[a]P), as well as DNA adducts, both in maternal and cord blood.
View Article and Find Full Text PDFBackground: While commercial aircraft are known sources of ultrafine particulate matter (UFP), the relationship between airport activity and local real-time UFP concentrations has not been quantified. Understanding these associations will facilitate interpretation of the exposure and health risk implications of UFP related to aviation emissions.
Objectives: We used time-resolved UFP data along with flight activity and meteorological information to determine the contributions of aircraft departures and arrivals to UFP concentrations.
Sources of air pollution in developing country cities include transportation and industrial pollution, biomass fuel use, and re-suspended dust from unpaved roads. We examined the spatial patterns of particulate matter (PM) and its sources in four neighborhoods of varying socioeconomic status (SES) in Accra. PM data were from 1 week of morning and afternoon mobile and stationary air pollution measurements in each of the study neighborhoods.
View Article and Find Full Text PDFJ Public Health Manag Pract
November 2012
Context: Availability of public neighborhood parks is associated with physical activity. Little is known about how parks contribute to population energy balance.
Purpose: This study estimated energy expenditure associated with the use of neighborhood parks and compared energy expenditure by activity areas within parks and by neighborhood race/ethnicity and income.
To address the knowledge gaps regarding inhalation exposure of flight crew to polybrominated diphenyl ethers (PBDEs) on airplanes, we measured PBDE concentrations in air samples collected in the cabin air at cruising altitudes and used Bayesian Decision Analysis (BDA) to evaluate the likelihood of inhalation exposure to result in the average daily dose (ADD) of a member of the flight crew to exceed EPA Reference Doses (RfDs), accounting for all other aircraft and non-aircraft exposures. A total of 59 air samples were collected from different aircraft and analyzed for four PBDE congeners-BDE 47, 99, 100 and 209 (a subset were also analyzed for BDE 183). For congeners with a published RfD, high estimates of ADD were calculated for all non-aircraft exposure pathways and non-inhalation exposure onboard aircraft; inhalation exposure limits were then derived based on the difference between the RfD and ADDs for all other exposure pathways.
View Article and Find Full Text PDFFast cysteine labelling of peptides promoted by an adjacent arginine has been observed with a standard labelling agent specific for amines, N-succinimidyl 4-[(18)F]fluorobenzoate.
View Article and Find Full Text PDFBackground: Although the entire duration of fetal development is generally considered a highly susceptible period, it is of public health interest to determine a narrower window of heightened vulnerability to polycyclic aromatic hydrocarbons (PAHs) in humans. We posited that exposure to PAHs during the first trimester impairs fetal growth more severely than a similar level of exposure during the subsequent trimesters.
Methods: In a group of healthy, non-smoking pregnant women with no known risks of adverse birth outcomes, personal exposure to eight airborne PAHs was monitored once during the second trimester for the entire cohort (n = 344), and once each trimester within a subset (n = 77).
In December 2008, the U.S. Consumer Product Safety Commission (CPSC) began receiving reports about odors, corrosion, and health concerns related to drywall originating from China.
View Article and Find Full Text PDFObjectives: To test an original scale assessing perceived barriers among school administrators to allowing community use of school recreational facilities outside of regular school hours.
Methods: Exploratory factor analysis (EFA) and confirmatory factor analysis (CFA).
Results: Using EFA and CFA, we found that a model including factors of legal/security, resources, and social support demonstrated the best relative fit for our data.
Exposure to fine particulate matter (PM) is a recognized risk factor for elevated blood pressure (BP) and cardiovascular disease in adults, and this prospective cohort study was undertaken to evaluate whether gestational exposure to PM(2.5) has a prohypertensive effect. We measured personal exposure to fine particulate matter (PM(2.
View Article and Find Full Text PDFParticulate matter (PM) is an important metric for studying the health effects of household air pollution. There are limited data on PM exposure for children in homes that use biomass fuels, and no previous study has used direct measurement of personal exposure in children younger than 5 years of age. We estimated PM(2.
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