Variation in European harbour seal immune response genes and susceptibility to phocine distemper virus (PDV)

Phocine distemper virus (PDV) has caused two mass mortalities of European harbour seals (Phoca vitulina) in recent decades. Levels of mortality varied considerably among European populations in both the 1988 and 2002 epidemics, with higher mortality in continental European populations in comparison to UK populations. High levels of genetic differentiation at neutral makers among seal populations allow for the possibility that there could be potential genetic differences at functional loci that may account for some of the variation in mortality. Recent genome sequencing of carnivore species and development of genomic tools have now made it possible to explore the possible contribution of variation in candidate genes from harbour seals in relation to the differential mortality patterns. We assessed variation in eight genes (CD46, IFNG, IL4, IL8, IL10, RARa, SLAM and TLR2) encoding key proteins involved in host cellular interactions with Morbilliviruses and the relationship of variants to disease status. This work constitutes the first genetic association study for Morbillivirus disease susceptibility in a non-model organism, and for a natural mortality event. We found no variation in harbour seals from across Europe in the protein coding domains of the viral receptors SLAM and CD46, but SNPs were present in SLAM intron 2. SNPs were also present in IL8 p2 and RARa exon 1. There was no significant association of SLAM or RARa polymorphisms with disease status implying no role of these genes in determining resistance to PDV induced mortality, that could be detected with the available samples and the small number of polymorphisms indentified. However there was significant differentiation of allele frequencies among populations. PDV and other morbilliviruses are important models for wildlife epidemiology, host switches and viral evolution. Despite a negative result in this case, full sequencing of pinniped and other ‘non-model’ carnivore genomes will help in refining understanding the role of host genetics in disease susceptibility for these viruses.     

V-region mutation in vitro,in vivo,and in silico reveal the importance of the enzymatic properties of AID and the sequence environment

The somatic hypermutation of Ig variable regions requires the activity of activation-induced cytidine deaminase (AID) which has previously been shown to preferentially deaminate WRC (W = A/T, R = A/G) motif hot spots in in vivo and in vitro assays. We compared mutation profiles of in vitro assays for the 3′ flanking intron of VhJ558-Jh4 region to previously reported in vivo profiles for the same region in the Msh2^−/−Ung^−/− mice that lack base excision and mismatch repair. We found that the in vitro and in vivo mutation profiles were highly correlated for the top (nontranscribed) strand, while for the bottom (transcribed) strand the correlation is far lower. We used an in silico model of AID activity to elucidate the relative importance of motif targeting in vivo. We found that the mutation process entails substantial complexity beyond motif targeting, a large part of which is captured in vitro. To elucidate the contribution of the sequence environment to the observed differences between the top and bottom strands, we analyzed intermutational distances. The bottom strand shows an approximately exponential distribution of distances in vivo and in vitro, as expected from a null model. However, the top strand deviates strongly from this distribution in that mutations approximately 50 nucleotides apart are greatly reduced, again both in vivo and in vitro, illustrating an important strand asymmetry. While we have confirmed that AID targeting of hot and cold spots is a key part of the mutation process, our results suggest that the sequence environment plays an equally important role.     

Radiographic measures of hyperinflation in clinical emphysema. Discrimination of patients from controls and relationship to physiologic and mechanical lung function

In a retrospective study we investigated the accuracy of radiographic measurements of hyperinflation in distinguishing a sample of patients with a clinical diagnosis of pulmonary emphysema (n = 44) from a sample of age- and sex-matched control subjects (n = 39). The relationship of the hyperinflation parameters to pulmonary function test results (PFTs) and arterial blood gas measurements (ABGs) in the emphysema patients was also examined. The radiographic measurements were diaphragmatic angle of depression, lung height, lung width, heart size, diaphragm level, radiographic total lung capacity (TLC), and size of the retrosternal air space. By discriminant function analysis, the best contributors to the function were lung height and diaphragmatic angle of depression, followed by radiographic TLC and heart size. The derived classification rule had a diagnostic accuracy of 88 percent. The radiographic measures, largely independent of one another, showed moderate correlations with percentage PFTs, ABGs, portable percentage spirometric studies, height, and weight. High correlations were found between several of the radiographic measurements and the PFTs that represent actual static lung volumes. The correlation between radiographically measured TLC and PFT TLC measured by the helium dilution technique was .90.     

Coincident plasma ACTH and corticosterone time series: Comparisons between young and old rats

Senescence is accompanied by a reduced ability to respond to a variety of physical and behavioral stressors. A sizable literature has been devoted to the interplay between hypothalamic-pituitary-adrenocortical axis dysfunction and senescence; yet, the precise interactions remain an enigma. Adrenocorticotropic hormone (ACTH) is secreted in pulsatile bursts generating complex signals in the plasma compartment that must be “read” by adrenocortical cells in order to initiate appropriate secretory responses. We have previously demonstrated subtle differences between young and old rats in the pattern of fluctuations in plasma ACTH concentrations over time, despite no difference in mean levels. The present work addressed the physiological significance of these differences in the plasma ACTH signal by analyzing the corresponding plasma corticosterone concentration time series and the relationship between these two hormones over time. Time series of integrated 10-min ACTH and corticosterone concentrations were collected over 4 h at the time of diurnal activation and analyzed in the time and frequency domains. The time of onset of the diurnal surge occurred 20 min later in old rats, and the ratio of corticosterone to ACTH was less at the time of onset and peak of the diurnal surge. Corticosterone levels were lower in old rats and mean ACTH and corticosterone levels were correlated in young but not old rats, as were maximum levels of the two hormones. Cross-correlation of ACTH and corticosterone time series and comparison of spectra were consistent with smoother fluctuations in plasma corticosterone in old animals with less variability at time scales less than 55 min. We conclude that age may be associated with a delay in diurnal activation of the HPA axis, a loss of sensitivity of adrenal corticosterone secretion to plasma ACTH levels, and a relative loss of high frequency variability in the corticosterone signal, as seen in many physiological systems with age.     

Cross GTPase-activating protein (CrossGAP)/Vilse links the Roundabout receptor to Rac to regulate midline repulsion

The regulators of the Rho-family GTPases, GTPase-activating proteins (GAPs) and guanine exchange factors (GEFs), play important roles in axon guidance. By means of a functional genomic study of the Rho-family GEFs and GAPs in Drosophila, we have identified a Rho-family GAP, CrossGAP (CrGAP), which is involved in Roundabout (Robo) receptor-mediated repulsive axon guidance. CrGAP physically associates with the Robo receptor. Too much or too little CrGAP activity leads to defects in Robo-mediated repulsion at the midline choice point. The CrGAP gain-of-function phenotype mimics the loss-of-function phenotypes of both Robo and Rac. Dosage-sensitive genetic interactions among CrGAP, Robo, and Rac support a model in which CrGAP transduces signals downstream of Robo receptor to regulate Rac-dependent cytoskeletal changes.     

Purification and characterization of a juvenile hormone binding protein from the hemolymph of the fourth instar tobacco hornworm, Manduca sexta

A protein which binds the insect juvenile hormone has been isolated from the hemolymph of the fourth instar tobacco hornworm, Manduca sexta (Lepidoptera). Bioassay and chemical characterization of the bound ligand from the purified binding protein indicates that this molecule is the primary macromolecule responsible for juvenile hormone transport in the hemolymph of this insect. The juvenile hormone binding protein has been purified using gel filtration, ion exchange chromatography and preparative polyacrylamide gel electrophoresis. The protein is a single polypeptide chain of about 28,000 daltons with a sedimentation coefficient of 2.2S and an isoelectric point of 5.0. Binding analysis using a hydroxyapatite batch assay indicates that the juvenile hormone binding protein has one binding site with a Ka of 1.2 times 10(7) M-1 at 4 degrees C.     

Acquisition of anal human papillomavirus (HPV) infection in women: the Hawaii HPV Cohort study

BACKGROUND: The majority of anal cancer is associated with human papillomavirus (HPV) infection, yet little is known about women's risk of acquisition of anal HPV infection. METHODS: Risk factors for the acquisition of anal HPV infection were examined in a longitudinal cohort study of 431 women, via repeated measurement of HPV DNA. RESULTS: Seventy percent of women were positive for anal HPV infection at one or more clinic visits from baseline through a follow-up period that averaged 1.3 years. The incidence of a high-risk (HR) infection was 19.5 (95% confidence interval [CI], 16.0-23.6) per 1000 woman-months. The most common incident HR HPV types were HPV-53, -52 and -16. The presence of an HR anal HPV infection at baseline increased the risk of an incident anal infection by 65%. Baseline HR cervical HPV infection also predicted the acquisition of an HR anal HPV infection (odds ratio, 1.81 [95% CI, 1.09-3.02]). Nonviral risk factors for acquisition of HR HPV infection included younger age, lower socioeconomic status, greater lifetime number of sexual partners, past use of hormones, and condom use. CONCLUSIONS: The results of this study suggest that women's risk of anal HPV infection is as common as their risk of cervical HPV infection.     

Dichloroacetate: Effects on exercise endurance in untrained rats

The effect of dichloroacetate (DCA), an activator of pyruvate dehydrogenase, on the performance of fed, untrained rats was evaluated while swimming for different durations. DCA-treated rats were able to swim almost 40% longer than controls (354 ± 18 versus 255 ± 18 sec, p < .001). This was associated with lower levels of blood and muscle lactate at rest and after 210 and 240 sec of swimming. At exhaustion, blood lactate was the same in the two groups even though the DCA rats had worked for an additional 99 sec (16.9 ± 1.2 versus 15.8 ± 1.2 mM/L NS). Pretreatment with DCA did not alter the usual exercise-induced decreases in muscle ATP and creatine phosphate or liver glycogen. After 210 sec of exercise, plasma FFA and blood glucose and acetoacetate were also the same in the two groups; however, β-hydroxybutyrate was somewhat higher, and there was a small but significant sparing of muscle glycogen in the DCA group. The data indicate that DCA enhances the ability of rats to exercise at near maximal work loads. They are consistent with the notion that improved endurance is a consequence of a decreased rate of lactate accumulation; however, the possibility that it is secondary to some other action of DCA cannot be excluded.     

Brief report: Risk factors for pneumococcal vaccine refusal in adults

Background: Invasive pneumococcal disease is a significant cause of morbidity and mortality in the United States. Despite availability of an effective vaccine, many patients refuse vaccination.
Objective: To investigate patient characteristics and features of the patient–provider relationship associated with pneumococcal vaccine refusal.
Design: Case–control study using chart review.
Patients: Five hundred adults from the medical clinics of a 1,000-bed inner-city teaching hospital.
Measurements and Main Results: Independent risk factors for pneumococcal vaccine refusal included patient–provider gender discordance (odds ratio (OR)=2.09, 95% confidence interval (CI) 1.07 to 4.09); a visit to a not-usual provider at the time of vaccine offering (OR=2.26, 95% CI 1.13 to 4.49); never having received influenza vaccination (OR=7.44, 95% CI 3.76 to 14.76); prior pneumococcal vaccine refusals (OR=3.45, 95% CI 1.60 to 7.43); and a history of ever having refused health maintenance tests (OR=2.86, 95% CI 1.40 to 5.84).
Conclusions: We have identified both patient factors and factors related to the patient–provider relationship that are risk factors for pneumococcal vaccine refusal. By identifying patients at risk for pneumococcal vaccine refusal, efforts to increase vaccination rates can be better targeted.