Association of 25-Hydroxyvitamin D status and genetic variation in the vitamin D metabolic pathway with FEV1 in the Framingham Heart Study

Background

Vitamin D is associated with lung function in cross-sectional studies, and vitamin D inadequacy is hypothesized to play a role in the pathogenesis of chronic obstructive pulmonary disease. Further data are needed to clarify the relation between vitamin D status, genetic variation in vitamin D metabolic genes, and cross-sectional and longitudinal changes in lung function in healthy adults.

Methods

We estimated the association between serum 25-hydroxyvitamin D [25(OH)D] and cross-sectional forced expiratory volume in the first second (FEV₁) in Framingham Heart Study (FHS) Offspring and Third Generation participants and the association between serum 25(OH)D and longitudinal change in FEV₁ in Third Generation participants using linear mixed-effects models. Using a gene-based approach, we investigated the association between 241 SNPs in 6 select vitamin D metabolic genes in relation to longitudinal change in FEV₁ in Offspring participants and pursued replication of these findings in a meta-analyzed set of 4 independent cohorts.

Results

We found a positive cross-sectional association between 25(OH)D and FEV₁ in FHS Offspring and Third Generation participants (P = 0.004). There was little or no association between 25(OH)D and longitudinal change in FEV₁ in Third Generation participants (P = 0.97). In Offspring participants, the CYP2R1 gene, hypothesized to influence usual serum 25(OH)D status, was associated with longitudinal change in FEV₁ (gene-based P < 0.05). The most significantly associated SNP from CYP2R1 had a consistent direction of association with FEV₁ in the meta-analyzed set of replication cohorts, but the association did not reach statistical significance thresholds (P = 0.09).

Conclusions

Serum 25(OH)D status was associated with cross-sectional FEV₁, but not longitudinal change in FEV₁. The inconsistent associations may be driven by differences in the groups studied. CYP2R1 demonstrated a gene-based association with longitudinal change in FEV₁ and is a promising candidate gene for further studies.

Electronic supplementary material

The online version of this article (doi:10.1186/s12931-015-0238-y) contains supplementary material, which is available to authorized users.     

Compartmentation of glutamate metabolism in brain. Evidence for the existence of two different tricarboxylic acid cycles in brain

1. (14)C from [1-(14)C]glucose injected intraperitoneally into mice is incorporated into glutamate, aspartate and glutamine in the brain to a much greater extent than (14)C from [2-(14)C]glucose. This difference for [1-(14)C]glucose and [2-(14)C]glucose increases with time. The amount of (14)C in C-1 of glutamate increases steadily with time with both precursors. It is suggested that a large part of the glutamate and aspartate pools in brain are in close contact with intermediates of a fast-turning tricarboxylic acid cycle. 2. (14)C from [1-(14)C]acetate and [2-(14)C]acetate is incorporated to a much larger extent into glutamine than into glutamate. An examination of the time-course of (14)C incorporated into glutamine and glutamate reveals that glutamine is not formed from the glutamate pool, labelled extensively by glucose, but from a small glutamate pool. This small glutamate pool is not derived from an intermediate of a fast-turning tricarboxylic acid cycle. 3. It is proposed that two different tricarboxylic acid cycles exist in brain.     

Functional knock down of VCAM1 in mice mediated by endoplasmatic reticulum retained intrabodies

Functional knockdowns mediated by endoplasmatic reticulum-retained antibodies (ER intrabodies) are a promising tool for research because they allow functional interference on the protein level. We demonstrate for the first time that ER intrabodies can induce a knock-down phenotype in mice. Surface VCAM1 was suppressed in bone marrow of heterozygous and homozygous ER intrabody mice (iER-VCAM1 mice). iER-VCAM1 mice did not have a lethal phenotype, in contrast to the constitutive knockout of VCAM1, but adult mice exhibited physiological effects in the form of aberrant distribution of immature B-cells in blood and bone marrow. The capability to regulate knock-down strength may spark a new approach for the functional study of membrane and plasma proteins, which may especially be valuable for generating mouse models that more closely resemble disease states than classic knockouts do.     

Mitochondrial DNA structure and colony expansion dynamics of New Zealand fur seals (Arctocephalus forsteri) around Banks Peninsula

New Zealand fur seals are one of many pinniped species that survived the commercial sealing of the eighteenth and nineteenth centuries in dangerously low numbers. After the enforcement of a series of protection measures in the early twentieth century, New Zealand fur seals began to recover from the brink of extinction. We examined the New Zealand fur seal populations of Banks Peninsula, South Island, New Zealand using the mitochondrial DNA control region. We identified a panmictic population structure around Banks Peninsula. The most abundant haplotype in the area showed a slight significant aggregated structure. The Horseshoe Bay colony showed the least number of shared haplotypes with other colonies, suggesting a different origin of re-colonisation of this specific colony. The effective population size of the New Zealand fur seal population at Banks Peninsula was estimated at approximately 2500 individuals. The exponential population growth rate parameter for the area was 35, which corresponds to an expanding population. In general, samples from adjacent colonies shared 4.4 haplotypes while samples collected from colonies separated by between five and eight bays shared 1.9 haplotypes. The genetic data support the spill-over dynamics of colony expansion already suggested for this species. Approximate Bayesian computations analysis suggests re-colonisation of the area from two main clades identified across New Zealand with a most likely admixture coefficient of 0.41 to form the Banks Peninsula population. Approximate Bayesian computations analysis estimated a founder population size of approximately 372 breeding individuals for the area, which then rapidly increased in size with successive waves of external recruitment. The population of fur seals in the area is probably in the late phase of maturity in the colony expansion dynamic.     

New Electropositive Filter for Concentrating Enteroviruses and Noroviruses from Large Volumes of Water

The U.S. Environmental Protection Agency''s information collection rule requires the use of 1MDS electropositive filters for concentrating enteric viruses from water, but unfortunately, these filters are not cost-effective for routine viral monitoring. In this study, an inexpensive electropositive cartridge filter, the NanoCeram filter, was evaluated for its ability to concentrate enteroviruses and noroviruses from large volumes of water. Seeded viruses were concentrated using the adsorption-elution procedure. The mean percent retention of seeded polioviruses by NanoCeram filters was 84%. To optimize the elution procedure, six protocols, each comprising two successive elutions with various lengths of filter immersion, were evaluated. The highest virus recovery (77%) was obtained by immersing the filters in beef extract for 1 minute during the first elution and for 15 min during the second elution. The recovery efficiencies of poliovirus, coxsackievirus B5, and echovirus 7 from 100-liter samples of seeded tap water were 54%, 27%, and 32%, respectively. There was no significant difference in virus recovery from tap water with a pH range of 6 to 9.5 and a water flow rate range of 5.5 liters/min to 20 liters/min. Finally, poliovirus and Norwalk virus recoveries by NanoCeram filters were compared to those by 1MDS filters, using tap water and Ohio River water. Poliovirus and Norwalk virus recoveries by NanoCeram filters from tap and river water were similar to or higher than those by the 1MDS filters. These data suggest that NanoCeram filters can be used as an inexpensive alternative to 1MDS filters for routine viral monitoring of water.Viruses that primarily infect and replicate in the gastrointestinal tract are known as enteric viruses. More than 140 different enteric viruses are known to infect humans. These include the enteroviruses, rotaviruses, hepatitis A virus, noroviruses, adenoviruses, and reoviruses, among others. Enteric viruses are capable of causing a wide range of illnesses, including gastroenteritis, paralysis, aseptic meningitis, herpangina, respiratory illness, fevers, myocarditis, etc. Given the potential public health impact of the enteric viruses, enteroviruses (echovirus and coxsackievirus), adenoviruses, and caliciviruses are on the U.S. Environmental Protection Agency''s contaminant candidate list 2 for regulatory consideration for drinking water (11). Within the Caliciviridae family, noroviruses are the primary viruses of concern for drinking water.Contaminated drinking water is considered to be a potential transmission route, and an infectious dose in humans may consist of only a small number of virus particles. Enteric viruses are introduced in aquatic environments through natural or human activities, such as leaking sewage and septic systems, urban runoff, landfills, injection of treated wastewater into aquifers, wastewater discharge, sewage outfall, etc. These viruses have been found in surface water, groundwater, and drinking water (1, 6, 13, 22, 26). Between 1971 and 2004, 789 drinking water outbreaks and 575,207 cases of illness were reported in the United States, and 8% of the reported outbreaks were due to enteric viruses (2, 5, 28, 29, 30, 46).The levels of enteric viruses in natural waters are often low, and as such, typical virus sampling involves a primary concentration of viruses from large volumes of water (hundreds to thousands of liters). Unlike other waterborne pathogens (such as bacteria and parasites), viruses are smaller, and thus, size exclusion filtration is often not practical, especially for turbid waters. In addition, viruses are negatively charged in natural environments and can be adsorbed onto a number of different matrices by electrostatic and hydrophobic interactions (16). Consequently, different types of matrices have been used to isolate enteric viruses from water. These include negatively and positively charged membranes or cartridge filters (10, 17, 32, 34, 35, 39), gauze pad (31), and glass powder or glass wool (14, 27). Of all of these methods, electronegative and electropositive filters are most commonly used. In the case of electronegative filters, the acidification of the water and addition of multivalent cations are required for optimal virus adsorption. Because of this need to condition the water to attain acceptable recoveries, it is difficult to use electronegative filters for field sampling. In contrast, electropositive filters do not require conditioning of the water. Among all the filters, 1MDS electropositive filters (Cuno, Meriden, CT) are the most commonly used filter for fresh and drinking water sampling; however, they are not cost-effective for routine viral monitoring of water and require pH adjustment for waters with pH values exceeding 8.0 (12).Viruses adsorbed on the filter are usually eluted and recovered using 1 to 1.6 liters of eluting solution (6, 12). Many different procedures are described in the literature to elute viruses from filters. These procedures include the use of different eluting solutions, such as 0.3%, 1.5% or 3% beef extract, urea-arginine phosphate buffer, glycine buffer, etc. (10, 12, 24, 37). There are also different elution processes, such as single elution, recirculation of eluents, or successive elution of filters (6, 8, 15, 43). Sobsey and Hickey (40) used only one elution with 0.3% beef extract in 50 mM glycine. Sobsey et al. (43) suggested that 1 liter of 1.5% beef extract be recirculated through the filters for 5 min. Dahling and Wright (8) reported that the highest virus recoveries were obtained by three elutions, each using 1.6 liters of 3% beef extract. Dahling (6) reported that the highest virus recoveries were obtained with two separate beef extract elutions, one being an overnight filter immersion in beef extract.Although methods for concentration of many enteric viruses have been developed, limited studies have been conducted for concentrating noroviruses from water. Huang et al. (21) described a norovirus concentration method using porcine calicivirus (Pan-1) as a surrogate. Pan-1 was sensitive to the high pH (9.5) of the eluting solution, which is commonly used. Myrmel et al. (33) described a method of norovirus concentration using feline calicivirus as a surrogate organism. The method used electronegative filters, and the recovery of virus was 5 to 10%. Many other studies reported detection of human noroviruses in environmental waters (18, 19, 25); however, none of these studies evaluated the recovery efficiencies of human noroviruses from large volumes of water.The objective of this study was to evaluate the NanoCeram (Argonide, Sanford, FL) cartridge filter for the concentration of enteroviruses and noroviruses from large volumes of water. NanoCeram filters have an active component of nano alumina (AlOOH) fibers, which give them a naturally occurring electropositive charge.     

Cloning, isolation and characterization of the Thermotoga maritima KDPG aldolase

The Thermotoga maritima aldolase gene has been cloned into a T7 expression vector and overexpressed in Escherichia coli. The preparation yields 470 UL(-1) of enzyme at a specific activity of 9.4 U mg(-1). During retroaldol cleavage of KDPG, the enzyme shows a k(cat) that decreases with decreasing temperature. A more than offsetting decrease in K(m) yields an enzyme that is more efficient at 40 degrees C than at 70 degrees C. The substrate specificity of the enzyme was evaluated in the synthetic direction with a range of aldehyde substrates. Although the protein shows considerable structural homology to KDPG aldolases from mesophilic sources, significant differences in substrate specificity exist. A preparative scale reaction between 2-pyridine carboxaldehyde and pyruvate provided product of the same absolute configuration as mesophilic enzymes, but with diminished stereoselectivity.     

Evaluation of an alternative IMS dissociation procedure for use with Method 1622: detection of Cryptosporidium in water

U.S. EPA Methods 1622 and 1623 are used to detect and quantify Cryptosporidium oocysts in water. The protocol consists of filtration, immunomagnetic separation (IMS), staining with a fluorescent antibody, and microscopic analysis. Microscopic analysis includes detection by fluorescent antibody and confirmation by the demonstration of 1-4 sporozoites or nuclei after staining with 4',6-diamidino-2-phenyl indole dihydrochloride (DAPI). The purpose of this study was to evaluate a new IMS dissociation, a 10-min incubation at 80 degrees C. Heat dissociation improved the average oocyst recovery from 41% to 71% in seeded reagent water, and from 10% to 51% in seeded river samples. The average DAPI confirmation rate improved from 49% to 93% in reagent water, and from 48% to 73% in river samples. This modification improved both oocyst recovery and confirmation.     

Molecular biology of insect olfaction:recent progress and conceptual models

Insects have an enormous impact on global public health as disease vectors and as agricultural enablers as well as pests and olfaction is an important sensory input to their behavior. As such it is of great value to understand the interplay of the molecular components of the olfactory system which, in addition to fostering a better understanding of insect neurobiology, may ultimately aid in devising novel intervention strategies to reduce disease transmission or crop damage. Since the first discovery of odorant receptors in vertebrates over a decade ago, much of our view on how the insect olfactory system might work has been derived from observations made in vertebrates and other invertebrates, such as lobsters or nematodes. Together with the advantages of a wide range of genetic tools, the identification of the first insect odorant receptors in Drosophila melanogaster in 1999 paved the way for rapid progress in unraveling the question of how olfactory signal transduction and processing occurs in the fruitfly. This review intends to summarize much of this progress and to point out some areas where advances can be expected in the near future.