Influenza virus evades prevailing natural and vaccine-induced immunity by accumulating antigenic change in the haemagglutinin surface protein. Linking amino acid substitutions in haemagglutinin epitopes to epidemiology has been problematic because of the scarcity of data connecting these scales. We use experiments on equine influenza virus to address this issue, quantifying how key parameters of viral establishment and shedding increase the probability of transmission with genetic distance between previously immunizing virus and challenge virus. Qualitatively similar patterns emerge from analyses based on antigenic distance and from a published human influenza study. Combination of the equine data and epidemiological models allows us to calculate the effective reproductive number of transmission as a function of relevant genetic change in the virus, illuminating the probability of influenza epidemics as a function of immunity.
Each year, influenza viruses cause epidemics by evading pre-existing humoral immunity through mutations in the major glycoproteins: the haemagglutinin (HA) and the neuraminidase (NA). In 2004, the antigenic evolution of HA of human influenza A (H3N2) viruses was mapped (Smith et al., Science
305, 371–376, 2004) from its introduction in humans in 1968 until 2003. The current study focused on the genetic evolution of NA and compared it with HA using the dataset of Smith and colleagues, updated to the epidemic of the 2009/2010 season. Phylogenetic trees and genetic maps were constructed to visualize the genetic evolution of NA and HA. The results revealed multiple reassortment events over the years. Overall rates of evolutionary change were lower for NA than for HA1 at the nucleotide level. Selection pressures were estimated, revealing an abundance of negatively selected sites and sparse positively selected sites. The differences found between the evolution of NA and HA1 warrant further analysis of the evolution of NA at the phenotypic level, as has been done previously for HA.
Recent literature has identified that musculoskeletal disorders (MSD) are a significant occupational health issue for both dentists and dental hygienists. Research on the occupational health of dental hygienists is lacking in Australia, which is of particular concern given that it is a rapidly growing field in this country. The aims of this research are to investigate the prevalence of MSD and correlating regions of pain among Australian dental hygienists. A self-reporting questionnaire was distributed to all registered dental hygienists in Australia. The questionnaire was a modified version of a validated tool, used previously among health practitioners and students.
A total of 624 dental hygienists responded to the questionnaire, achieving a response rate of 42%. MSD were frequently reported by dental hygienists in the neck (85%), shoulder (70%), and lower back (68%). Of those reporting pain, over two thirds reported that the pain lasted for longer than two days, for all body regions. Logistic regression analysis revealed that there is a correlation between reports of MSD in the neck, shoulder and lower back regions.
Overall, this study suggests that MSD are a reasonably common problem for Australian dental hygienists, and that they often need to seek medical treatment for these problems. It is concerning that there is a correlation between reports of MSD in the neck, shoulder and lower back regions; further studies are needed to establish the epidemiological patterns of MSD in this profession.
Musculoskeletal disorders; Dental hygienist; Occupational health
Hfq is an RNA-binding protein that functions in post-transcriptional gene regulation by mediating interactions between mRNAs and small regulatory RNAs (sRNAs). Two proteins encoded by BAB1_1794 and BAB2_0612 are highly overproduced in a Brucella abortus hfq mutant compared to the parental strain, and recently, expression of orthologs of these proteins in Agrobacterium tumefaciens was shown to be regulated by two sRNAs, called AbcR1 and AbcR2. Orthologous sRNAs (likewise designated AbcR1 and AbcR2) have been identified in B. abortus 2308. In Brucella, abcR1 and abcR2 single mutants are not defective in their ability to survive in cultured murine macrophages, but an abcR1 abcR2 Sdouble mutant exhibits significant attenuation in macrophages. Additionally, the abcR1 abcR2 double mutant displays significant attenuation in a mouse model of chronic Brucella infection. Quantitative proteomics and microarray analyses revealed that the AbcR sRNAs predominantly regulate genes predicted to be involved in amino acid and polyamine transport and metabolism, and Northern blot analyses indicate that the AbcR sRNAs accelerate the degradation of the target mRNAs. In an E. coli two-plasmid reporter system, over-expression of either AbcR1 or AbcR2 was sufficient for regulation of target mRNAs, indicating that the AbcR sRNAs from Brucella abortus 2308 perform redundant regulatory functions.
Haemagglutinin is a determinant of many viral properties, and successful adaptation to a human-like form is thought to be an important step toward pandemic influenza emergence. The availability of structurally distinct sialic acid linked receptors in the sites of human and avian influenza infection are generally held to account for the differences observed, but the relevance of other selection pressures has not been elucidated. There is evidence for genetic and structural constraints of haemagglutinin playing a role in restricting haemagglutinin adaptation, and also for differences in the selection pressure to alter binding, specifically when considering virus replication within host compared to transmission between hosts. Understanding which characteristics underlie such adaptations in humans is now possible in greater detail by using glycan arrays. However, results from these assays must also interpreted in context of an as yet still to be determined detailed knowledge of the structural diversity of sialic acids in the human respiratory tract. A clearer understanding of the evolutionary benefits conveyed by different haemagglutinin properties would have substantial impact and would affect the risk we allocate to viral propagation in different species, such as swine and poultry. Relevant to the H5N1 threat, current evidence also suggests that mortality associated with any emergent pandemic from current strains may be reduced if haemagglutinin specificity changes, further emphasising the importance of understanding how and if selection pressures in the human will cause such an alteration.
Recent technical advances in the field of quantitative proteomics have stimulated a large number of biomarker discovery studies of various diseases, providing avenues for new treatments and diagnostics. However, inherent challenges have limited the successful translation of candidate biomarkers into clinical use, thus highlighting the need for a robust analytical methodology to transition from biomarker discovery to clinical implementation. We have developed an end-to-end computational proteomic pipeline for biomarkers studies. At the discovery stage, the pipeline emphasizes different aspects of experimental design, appropriate statistical methodologies, and quality assessment of results. At the validation stage, the pipeline focuses on the migration of the results to a platform appropriate for external validation, and the development of a classifier score based on corroborated protein biomarkers. At the last stage towards clinical implementation, the main aims are to develop and validate an assay suitable for clinical deployment, and to calibrate the biomarker classifier using the developed assay. The proposed pipeline was applied to a biomarker study in cardiac transplantation aimed at developing a minimally invasive clinical test to monitor acute rejection. Starting with an untargeted screening of the human plasma proteome, five candidate biomarker proteins were identified. Rejection-regulated proteins reflect cellular and humoral immune responses, acute phase inflammatory pathways, and lipid metabolism biological processes. A multiplex multiple reaction monitoring mass-spectrometry (MRM-MS) assay was developed for the five candidate biomarkers and validated by enzyme-linked immune-sorbent (ELISA) and immunonephelometric assays (INA). A classifier score based on corroborated proteins demonstrated that the developed MRM-MS assay provides an appropriate methodology for an external validation, which is still in progress. Plasma proteomic biomarkers of acute cardiac rejection may offer a relevant post-transplant monitoring tool to effectively guide clinical care. The proposed computational pipeline is highly applicable to a wide range of biomarker proteomic studies.
Novel proteomic technology has led to the generation of vast amounts of biological data and the identification of numerous potential biomarkers. However, computational approaches to translate this information into knowledge capable of impacting clinical care have been lagging. We propose a computational proteomic pipeline for biomarker studies that is founded on the combination of advanced statistical methodologies. We demonstrate our approach through the analysis of data obtained from heart transplant patients. Heart transplantation is the gold standard treatment for patients with end-stage heart failure, but is complicated by episodes of immune rejection that can adversely impact patient outcomes. Current rejection monitoring approaches are highly invasive, requiring a biopsy of the heart. This work aims to reduce the need for biopsies, and demonstrate the power and utility of computational approaches in proteomic biomarker discovery. Our work utilizes novel high-throughput proteomic technology combined with advanced statistical techniques to identify blood markers that guide the decision as to whether a biopsy is warranted, reduce the number of unnecessary biopsies, and ultimately diagnose the presence of rejection in heart transplant patients. Additionally, the proposed computational methodologies can be applied to a range of proteomic biomarker studies of various diseases and conditions.
The Caucasus, at the border of Europe and Asia, is important for migration and over-wintering of wild waterbirds. Three flyways, the Central Asian, East Africa-West Asia, and Mediterranean/Black Sea flyways, converge in the Caucasus region. Thus, the Caucasus region might act as a migratory bridge for influenza virus transmission when birds aggregate in high concentrations in the post-breeding, migrating and overwintering periods. Since August 2009, we have established a surveillance network for influenza viruses in wild birds, using five sample areas geographically spread throughout suitable habitats in both eastern and western Georgia. We took paired tracheal and cloacal swabs and fresh feces samples. We collected 8343 swabs from 76 species belonging to 17 families in 11 orders of birds, of which 84 were real-time RT-PCR positive for avian influenza virus (AIV). No highly pathogenic AIV (HPAIV) H5 or H7 viruses were detected. The overall AIV prevalence was 1.6%. We observed peak prevalence in large gulls during the autumn migration (5.3–9.8%), but peak prevalence in Black-headed Gulls in spring (4.2–13%). In ducks, we observed increased AIV prevalence during the autumn post-moult aggregations and migration stop-over period (6.3%) but at lower levels to those observed in other more northerly post-moult areas in Eurasia. We observed another prevalence peak in the overwintering period (0.14–5.9%). Serological and virological monitoring of a breeding colony of Armenian Gulls showed that adult birds were seropositive on arrival at the breeding colony, but juveniles remained serologically and virologically negative for AIV throughout their time on the breeding grounds, in contrast to gull AIV data from other geographic regions. We show that close phylogenetic relatives of viruses isolated in Georgia are sourced from a wide geographic area throughout Western and Central Eurasia, and from areas that are represented by multiple different flyways, likely linking different host sub-populations.
Influenza vaccination rates among Japanese people of working age (20–69 years) is currently suboptimal, and the reasons for this have not been clearly elucidated. This study examined factors associated with vaccination intention among the working age population in Japan during September 2011, one-month prior to influenza vaccination becoming available.
A web-based survey of intention to be vaccinated against influenza in the coming season was undertaken among 3,129 Japanese aged 20 to 69 years. Multinomial logistic regression analysis was used to explore the associations between vaccination intent and other variables. Influenza vaccination intent was associated with having been vaccinated in the previous year (Odds Ratio (OR): 3.81; 95% Confidence Interval (CI): 3.75–3.86), the number of children per household (one compared with zero; OR: 1.37; 95%CI: 1.11–1.65), and household income ($50,000 to <$100,000 compared with $0 to <$50,000; OR: 1.30; 95%CI: 1.07–1.54). Smoking was inversely associated with influenza vaccine uptake (current smokers compared with non-smokers; OR: 0.79; 95%CI: 0.61–0.98). A history of either the survey respondent or a household member having being medically diagnosed with influenza in the previous year was not statistically associated with future influenza vaccination intent.
Overall, this suggests that intention to be vaccinated among working age Japanese is associated with a past history of influenza vaccination, having children, and the household's income. As such, consideration of these factors should now form the cornerstone of strategies to encourage increased uptake of vaccination against influenza in future years.
Exposure of rhesus macaque fetuses for 24 h, or neonates for 9 h, to ketamine anesthesia causes neuroapoptosis in the developing brain. The present study further clarifies the minimum exposure required for, and the extent and spatial distribution of, ketamine-induced neuroapoptosis in rhesus fetuses and neonates.
Ketamine was administered by intravenous infusion for 5 h to postnatal day 6 rhesus neonates, or to pregnant rhesus females at 120 days gestation (full term = 165 days). Three hours later, fetuses were delivered by caesarian section, and the fetal and neonatal brains were studied for evidence of apoptotic neurodegeneration, as determined by activated caspase-3 staining.
Both the fetal (n = 3) and neonatal (n = 4) ketamine-exposed brains had a significant increase in apoptotic profiles compared to drug-naive controls (fetal n = 4; neonatal n = 5). Loss of neurons due to ketamine exposure was 2.2 times greater in fetuses than in neonates. The pattern of neurodegeneration in fetuses was different from that in neonates, and all subjects exposed at either age had a pattern characteristic for that age.
The developing rhesus macaque brain is sensitive to the apoptogenic action of ketamine at both a fetal and neonatal age, and exposure duration of 5 h is sufficient to induce a significant neuroapoptosis response at either age. The pattern of neurodegeneration induced by ketamine in fetuses was different from that in neonates, and loss of neurons attributable to ketamine exposure was 2.2 times greater in the fetal than neonatal brains.
Although there has been a downward trend in smoking rates among medical doctors in recent years, rates have been higher among Japanese doctors when compared internationally.
We extensively reviewed all published English- and Japanese-language articles that reported the smoking rates of Japanese doctors.
A total of 36 articles were examined, most of which had been conducted as postal surveys, usually by a national, prefectural, or local medical association. Sample sizes ranged from 17 to 11 773, and response rates ranged from 33% to 91%. National surveys conducted between 1965 and 2009 suggest that there has been a statistically significant (P < 0.0001) decline in smoking rates among Japanese doctors (from around 68% to 16% among males and from 19% to 5% among females).
Overall, the published data reveal a significant decline in smoking rates among Japanese doctors since 1965, especially among men. Although less than one-fifth of Japanese male doctors now smoke, more work needs to be done in tobacco control to help further reduce the burden of smoking, especially in medical schools.
smoking; tobacco; physician; doctor; Japan
Although the wearing of face masks in public has not been recommended for preventing influenza, these devices are often worn in many Asian countries during the influenza season. In Japan, it is thought that such behavior may be an indicator of other positive hygiene practices. The aim of this study, therefore, was to determine if wearing a face mask in public is associated with other positive hygiene practices and health behaviors among Japanese adults.
We initially recruited around 3,000 Japanese individuals ranging from 20 to 69 years of age who were registered with a web survey company. Participants were asked to recall their personal hygiene practices during the influenza season of the previous year. Logistic regression analysis was then used to examine the associations between wearing a face mask in public and personal hygiene practices and health behaviors.
A total of 3,129 persons responded to the survey, among whom 38% reported that they had worn a face mask in public during the previous influenza season. Wearing a face mask in public was associated with various self-reported hygiene practices including: frequent hand washing (adjusted Odds Ratio [OR]: 1.67; 95% Confidence Interval [95%CI]: 1.34-1.96), occasional hand washing (OR: 1.43; 95%CI: 1.10-1.75), frequently avoiding crowds (OR: 1.85; 95%CI: 1.70-1.98), occasionally avoiding crowds (OR: 1.65; 95%CI: 1.53-1.76), frequent gargling (OR: 1.68; 95%CI: 1.51-1.84), occasional gargling (OR: 1.46; 95%CI: 1.29-1.62), regularly avoiding close contact with an infected person (OR: 1.50; 95%CI: 1.33-1.67), occasionally avoiding close contact with an infected person (OR: 1.31; 95%CI: 1.16-1.46), and being vaccinated of influenza in the last season (OR: 1.31; 95%CI: 1.17-1.45).
Overall, this study suggests that wearing a face mask in public may be associated with other personal hygiene practices and health behaviors among Japanese adults. Rather than preventing influenza itself, face mask use might instead be a marker of additional, positive hygiene practices and other favorable health behaviors in the same individuals.
Face mask; Health behavior; Hygiene practices; Influenza
Foot ulcerations complicated by infection are the major cause of limb loss in people with diabetes. This is especially true in those patients with severe sepsis. Determining whether to amputate or attempt to salvage a limb often requires in depth evaluation of each individual patient's physical, mental, and socioeconomic status. The current report presents and juxtaposes two similar patients, admitted to the same service at the same time with severe diabetic foot infections complicated by sepsis. We describe in detail the similarities and differences in the clinical presentation, extent of infection, etiology, and socioeconomic concerns that ultimately led to divergent clinical decisions regarding the choices of attempting diabetic limb salvage versus primary amputation and prompt rehabilitation.
diabetic foot; Charcot arthropathy; diabetic limb salvage; diabetic foot infection; amputation
Tobacco control represents a key area in which doctors can make a significant positive impact on their patients’ lives. Despite this fact, however, doctors in certain regions of China are known to smoke tobacco at rates similar to or even exceeding those seen within the general population.
This study sought to investigate the smoking habits of doctors at a teaching hospital in Shandong province, as well as providing a brief review of smoking research that has been conducted among doctors elsewhere in China.
An anonymous questionnaire survey was distributed to doctors working at a university teaching hospital in 2008, as part of a larger study of occupational health issues in the healthcare profession.
The overall smoking prevalence rate of doctors in this study was 36.3% with significant differences observed between the genders (males: 46.7% and females: 5.3%). Age and total career length were also correlated with smoking habit, although no significant associations were found with department of employment.
Overall, our study suggests that smoking rates among doctors in Shandong province are higher than those documented in many other countries, a finding which is consistent with previous research conducted in some other Chinese provinces. Addressing this issue from an intrinsic cultural perspective will clearly need to form the cornerstone of tobacco control efforts within the Chinese medical community in future years.
China; Chinese; Doctor; Physician; Smoking; Tobacco; Medical
Purpose: Research encompassing the characteristics of chiropractic students is limited. The purpose of our study was to evaluate a current chiropractic student population enrolled at a chiropractic college concerning demographics, expectations, and beliefs. Methods: A 44-item survey was administered to volunteer participants. Direct verbal interaction in a classroom setting to potential participants was the recruitment strategy used. Data were collected and stored on a safe network. Percentages for all responses were calculated and means were recorded where appropriate. Results: A total of 664 students participated of 877 potential eligible candidates (75%). The respondents tended to be 21–25 years of age, Caucasian, and male. Most respondents expected to work in a private practice immediately following graduation and anticipated an annual income of at least $100,000 eventually. Respondents preferred the retaining of the term, “subluxation,” and identified the importance of new and emerging scientific data. Additionally, respondents held the viewpoint that some non-musculoskeletal diseases can be treated effectively with spinal manipulation as a primary treatment. Conclusions: The majority of chiropractic students in our study were represented by specific demographic characteristics, and a strong favoritism toward the expectations of working in a private practice setting and earning at least $100,000 per year at some point in their career. Distinct beliefs are shared between chiropractic students and practicing chiropractors in North America, and certain aspects of students in our study are comparable to chiropractic students in similar studies.
Attitude; Chiropractic; Cross Sectional Survey; Education; Students
Avian A/H5N1 influenza viruses pose a pandemic threat. As few as five amino acid substitutions, or four with reassortment, might be sufficient for mammal-to-mammal transmission by respiratory droplets. From surveillance data we find that two of these substitutions are common in A/H5N1 viruses and thus some viruses might require only three additional substitutions to become transmissible via respiratory droplets between mammals. We use a mathematical model of within-host virus evolution to study factors that could increase and decrease the probability of the remaining substitutions evolving after the virus has infected a mammalian host. These factors combined with the presence of some of these substitutions in circulating strains, make a virus evolving in nature a potentially serious threat. These results highlight critical areas where more data are needed for assessing, and potentially averting, this threat.
Glucocorticoids are used to treat respiratory dysfunction associated with premature birth but have been shown to cause neurodevelopmental deficits when used therapeutically. Recently, we established that acute glucocorticoid exposure at clinically relevant doses produces neural progenitor cell apoptosis in the external granule layer of the developing mouse cerebellum and permanent decreases in the number of cerebellar neurons. As the cerebellum naturally matures and neurogenesis is no longer needed, the external granule layer decreases proliferation and permanently disappears during the second week of life. At this same time, corticosterone (the endogenous rodent glucocorticoid) release increases and a glucocorticoid-metabolizing enzyme that protects the external granule layer against glucocorticoid receptor stimulation (11B-Hydroxysteroid-Dehydrogenase-Type 2; HSD2) naturally disappears. Here we show that HSD2 inhibition or raising corticosterone to adult physiological levels can both independently increase neural progenitor cell apoptosis in the neonatal mouse. Conversely, glucocorticoid receptor antagonism decreased natural physiological apoptosis in this same progenitor cell population suggesting endogenous glucocorticoid stimulation may regulate apoptosis in the external granule layer. We also found that glucocorticoids HSD2 can effectively metabolize generate less external granule layer apoptosis then glucocorticoids this enzyme is ineffective at breaking down. This finding may explain why glucocorticoids this enzyme can metabolize are clinically effective at treating respiratory dysfunction yet seem to produce no neurodevelopmental deficits. Finally, we demonstrate that both acute and chronic glucocorticoid exposure produces external granule layer apoptosis but without appropriate control groups this effect becomes masked. These results are discussed in terms of their implications for glucocortiocid therapy and neurodevelopment during the perinatal period.
apoptosis; neural progenitor cell; cerebellum; glucocorticoid; dexamethasone; betamethasone; bronchopulmonary dysplasia; chronic lung disease; premature birth; neurodevelopment
Marine and freshwater scientists are potentially exposed to a wide variety of occupational hazards. Depending on the focus of their research, risks may include animal attacks, physiological stresses, exposure to toxins and carcinogens, and dangerous environmental conditions. Many of these hazards have been investigated amongst the general population in their recreational use of the environment; however, very few studies have specifically related potential hazards to occupational exposure. For example, while the incidence of shark and crocodile attacks may invoke strong emotions and the occupational risk of working with these animals is certainly real, many more people are stung by jellyfish or bitten by snakes or dogs each year. Furthermore, a large proportion of SCUBA-related injuries and deaths are incurred by novice or uncertified divers, rather than professional divers using aquatic environments. Nonetheless, marine and freshwater research remains a potentially risky occupation, and the likelihood of death, injury and long-term health impacts still needs to be seriously considered.
Exposure; Hazard; Injury; Occupational health; Research; Risk
Dengue viruses (DENV) cause countless human deaths each year, whilst West Nile virus (WNV) has re-emerged as an important human pathogen. There are currently no WNV or DENV vaccines licensed for human use, yet vaccines exist against other flaviviruses. To investigate flavivirus cross-reactivity, sera from a human cohort with a history of vaccination against tick-borne encephalitis virus (TBEV), Japanese encephalitis virus (JEV) and yellow fever virus (YFV) were tested for antibodies by plaque reduction neutralization test. Neutralization of louping ill virus (LIV) occurred, but no significant neutralization of Murray Valley encephalitis virus was observed. Sera from some individuals vaccinated against TBEV and JEV neutralized WNV, which was enhanced by YFV vaccination in some recipients. Similarly, some individuals neutralized DENV-2, but this was not significantly influenced by YFV vaccination. Antigenic cartography techniques were used to generate a geometric illustration of the neutralization titres of selected sera against WNV, TBEV, JEV, LIV, YFV and DENV-2. This demonstrated the individual variation in antibody responses. Most sera had detectable titres against LIV and some had titres against WNV and DENV-2. Generally, LIV titres were similar to titres against TBEV, confirming the close antigenic relationship between TBEV and LIV. JEV was also antigenically closer to TBEV than WNV, using these sera. The use of sera from individuals vaccinated against multiple pathogens is unique relative to previous applications of antigenic cartography techniques. It is evident from these data that notable differences exist between amino acid sequence identity and mapped antigenic relationships within the family Flaviviridae.
Musculoskeletal disorders (MSD) represent one of the most common and most expensive occupational health problems in both developed and developing countries. School teachers represent an occupational group among which there appears to be a high prevalence of MSD. Given that causes of MSD have been described as multi-factorial and prevalence rates vary between body sites and location of study, the objective of this systematic review was to investigate the prevalence and risk factors for MSD among teaching staff.
The study involved an extensive search of MEDLINE and EMBASE databases in 2011. All studies which reported on the prevalence and/or risk factors for MSD in the teaching profession were initially selected for inclusion. Reference lists of articles identified in the original search were then examined for additional publications. Of the 80 articles initially located, a final group of 33 met the inclusion criteria and were examined in detail.
This review suggests that the prevalence of self-reported MSD among school teachers ranges between 39% and 95%. The most prevalent body sites appear to be the back, neck and upper limbs. Nursery school teachers appear to be more likely to report suffering from low back pain. Factors such as gender, age, length of employment and awkward posture have been associated with higher MSD prevalence rates.
Overall, this study suggests that school teachers are at a high risk of MSD. Further research, preferably longitudinal, is required to more thoroughly investigate the issue of MSD among teachers, with a greater emphasis on the possible wider use of ergonomic principles. This would represent a major step forward in the prevention of MSD among teachers, especially if easy to implement control measures could be recommended.
The clinical impact of the 2009 pandemic influenza A(H1N1) virus (pdmH1N1) has been relatively low. However, amino acid substitution D222G in the hemagglutinin of pdmH1N1 has been associated with cases of severe disease and fatalities. D222G was introduced in a prototype pdmH1N1 by reverse genetics, and the effect on virus receptor binding, replication, antigenic properties, and pathogenesis and transmission in animal models was investigated. pdmH1N1 with D222G caused ocular disease in mice without further indications of enhanced virulence in mice and ferrets. pdmH1N1 with D222G retained transmissibility via aerosols or respiratory droplets in ferrets and guinea pigs. The virus displayed changes in attachment to human respiratory tissues in vitro, in particular increased binding to macrophages and type II pneumocytes in the alveoli and to tracheal and bronchial submucosal glands. Virus attachment studies further indicated that pdmH1N1 with D222G acquired dual receptor specificity for complex α2,3- and α2,6-linked sialic acids. Molecular dynamics modeling of the hemagglutinin structure provided an explanation for the retention of α2,6 binding. Altered receptor specificity of the virus with D222G thus affected interaction with cells of the human lower respiratory tract, possibly explaining the observed association with enhanced disease in humans.
Prior to the introduction of the 2009 pandemic H1N1 virus from humans into pigs, four phylogenetic clusters (α-, β-, γ- and δ) of the haemagglutinin (HA) gene from H1 influenza viruses could be found in US swine. Information regarding the antigenic relatedness of the H1 viruses was lacking due to the dynamic and variable nature of swine lineage H1. We characterized 12 H1 isolates from 2008 by using 454 genome-sequencing technology and phylogenetic analysis of all eight gene segments and by serological cross-reactivity in the haemagglutination inhibition (HI) assay. Genetic diversity was demonstrated in all gene segments, but most notably in the HA gene. The gene segments from the 2009 pandemic H1N1 formed clusters separate from North American swine lineage viruses, suggesting progenitors of the pandemic virus were not present in US pigs immediately prior to 2009. Serological cross-reactivity paired with antigenic cartography demonstrated that the viruses in the different phylogenetic clusters are also antigenically divergent.
Plasma biomarkers studies are based on the differential expression of proteins between different treatment groups or between diseased and control populations. Most mass spectrometry-based methods of protein quantitation, however, are based on the detection and quantitation of peptides, not intact proteins. For peptide-based protein quantitation to be accurate, the digestion protocols used in proteomic analyses must be both efficient and reproducible. There have been very few studies, however, where plasma denaturation/digestion protocols have been compared using absolute quantitation methods. In this paper, 14 combinations of heat, solvent [acetonitrile, methanol, trifluoroethanol], chaotropic agents [guanidine hydrochloride, urea], and surfactants [sodium dodecyl sulfate (SDS) and sodium deoxycholate (DOC)] were compared with respect to their effectiveness in improving subsequent tryptic digestion. These digestion protocols were evaluated by quantitating the production of proteotypic tryptic peptides from 45 moderate- to high-abundance plasma proteins, using tandem mass spectrometry in multiple reaction monitoring mode, with a mixture of stable-isotope labeled analogues of these proteotypic peptides as internal standards. When the digestion efficiencies of these 14 methods were compared, we found that both of the surfactants (SDS and DOC) produced an increase in the overall yield of tryptic peptides from these 45 proteins, when compared to the more commonly used urea protocol. SDS, however, can be a serious interference for subsequent mass spectrometry. DOC, on the other hand, can be easily removed from the samples by acid precipitation. Examining the results of a reproducibility study, done with 5 replicate digestions, DOC and SDS with a 9 h digestion time produced the highest average digestion efficiencies (~80%), with the highest average reproducibility (<5% error, defined as the relative deviation from the mean value). However, because of potential interferences resulting from the use of SDS, we recommend DOC with a 9 h digestion procedure as the optimum protocol.
protein digestion; deoxycholate; urea; sodium dodecyl sulfate; heat denaturation; solvent denaturation
Nearly 50% of U.S. women of child-bearing age are overweight or obese, conditions linked to offspring obesity and diabetes.
Utilizing the sheep, females were fed a highly palatable diet at two levels of overfeeding designed to induce different levels of maternal body weight increase and adiposity at conception, and from conception to midgestation. Fetal growth and organ development were then evaluated at midgestation in response to these two different levels of overfeeding. Ewes were fed to achieve: 1) normal weight gain (control, C), 2) overweight (125% of National Research Council [NRC] recommendations, OW125) or 3) obesity (150% of NRC recommendations, OB150) beginning 10 wks prior to breeding and through midgestation. Body fat % and insulin sensitivity were assessed at three points during the study: 1) diet initiation, 2) conception and 3) mid-gestation. Ewes were necropsied and fetuses recovered at mid-gestation (day 78).
OB150 ewes had a higher % body fat than OW125 ewes prior to breeding (P = 0.03), but not at mid-gestation (P = 0.37). Insulin sensitivity decreased from diet initiation to mid-gestation (P = 0.04), and acute insulin response to glucose tended to be greater in OB150 ewes than C ewes (P = 0.09) and was greater than in OW125 ewes (P = 0.02). Fetal crown-rump length, thoracic and abdominal girths, and fetal perirenal fat were increased in the OW125 and OB150 versus C ewes at mid-gestation. However, only fetal heart, pancreas, and liver weights, as well as lipid content of fetal liver, were increased (P < 0.05) in OB150 ewes versus both C and OW125 ewes at midgestation.
These data demonstrate that different levels of overfeeding, resulting in differing levels of maternal weight gain and adiposity prior to and during pregnancy, lead to differential effects on fetal overgrowth and organ development.
In light of the 2009 influenza pandemic and potential future pandemics, Maria Van Kerkhove and colleagues anticipate six public health challenges and the data needed to support sound public health decision making.
Magnesium sulfate (MgSO4) is often used as a treatment for pre-eclampsia/eclampsia and preterm labor, resulting in the exposure of a significant number of neonates to this drug despite a lack of evidence suggesting that it is safe, or effective as a tocolytic. While there is evidence that MgSO4 may be neuroprotective in perinatal brain injury, recent reviews have suggested that the effects are dependent upon dose, and that higher doses may actually increase neonatal morbidity and mortality. There is a lack of evidence investigating the neurotoxic effects of neonatal magnesium (Mg) exposure on the developing brain, specifically in terms of neurodevelopmental apoptosis, a cell-killing phenomenon known to be potentiated by other drugs with mechanisms of action at Mg-binding sites (i.e. NMDA receptor antagonists such as MK-801, ketamine, and PCP).
To investigate the effects of Mg exposure on the neonatal mouse brain at different postnatal ages to determine whether MgSO4 treatment causes significant cell death in the developing mouse brain.
C57Bl/6 mice were treated with four doses of MgSO4 (250 mg/kg) on postnatal days 3 (P3), 7 (P7) or 14 (P14). Caspase-3 immunohistochemistry, cupric silver staining, and electron microscopy techniques were used to examine Mg-treated brains for neurotoxic effects.
Qualitative evaluation using cupric silver staining revealed widespread damage throughout the brain in P7 animals. Results of electron microscopy confirmed that the cell death process was apoptotic in nature. Quantitative evaluation of damage to the cortex, caudate-putamen, hippocampus, thalamus, and cerebellum showed that Mg treatment caused significant brain damage in animals treated on P3 and P7, but not P14.
Administration of high doses of Mg may be detrimental to the fetal brain, particularly if exposure occurs during critical periods of neurodevelopment.
Magnesium sulfate; Apoptosis; Caspase-3; Pre-eclampsia; Preterm labor; Neurodevelopment