Achievements by CSGMT/JEMS·MMS: the Collaborative Study Group for the Micronucleus Test in the Mammalian Mutagenesis Study Group of the Environmental Mutagen Society of Japan

The Collaborative Study Group for the Micronucleus Test (CSGMT) is one of the task groups in the Mammalian Mutagenesis Study Group (MMS) of the Environmental Mutagen Society of Japan (JEMS). It was established in 1982 and has made efforts to understand what the micronucleus test is, what are the advantages and disadvantages of the test as an in vivo detection system for mutagens/carcinogens, and to establish a standard protocol applicable to numerous chemicals. Members of the CSGMT have published more than 75 papers as part of collaborative studies and have contributed to the understanding of the nature of the micronucleus test and to setting guidelines for testing of medicinal and other chemicals. The CSGMT held some workshops to share up-to-date knowledge and techniques on the micronucleus test. Through workshops and collaborative studies, the CSGMT contributed to the maintaining of a high standard of knowledge and techniques among Japanese researchers of the micronucleus test. This paper reviews achievements made by the CSGMT until now.     

Indigenous Research: A Commitment to Walking the Talk. The Gudaga Study—an Australian Case Study

Increasingly, the role of health research in improving the discrepancies in health outcomes between Indigenous and non-Indigenous populations in developed countries is being recognised. Along with this comes the recognition that health research must be conducted in a manner that is culturally appropriate and ethically sound. Two key documents have been produced in Australia, known as The Road Map and The Guidelines, to provide theoretical and philosophical direction to the ethics of Indigenous health research. These documents identify research themes considered critical to improving the health of the nation’s Indigenous peoples. They also provide values that, from an Indigenous perspective, are foundational to an ethical research process. This paper examines these research themes and values within the context of a current longitudinal birth cohort study of Indigenous infants and children in south-west Sydney: the Gudaga Study. Considerable time and effort have been invested in being true to the values stated in these documents: reciprocity; respect; equality; responsibility; survival and protection; and spirit and integrity. We have learnt that it is vital to be true to these values when conducting Indigenous health research—to quite literally “walk the talk”.     

Exploring the Interdependence of Couples' Rest‐Wake Cycles: An Actigraphic Study

Within western societies, it is commonplace for couples to share a bed. Yet there has been remarkably little research carried out on couples' sleep. This paper draws upon actigraphy, audio diary, and questionnaire data from both partners of 36 heterosexual couples (age 20–59 yrs) and aims to quantify the extent to which it is important to take into account the dyadic nature of sleep‐wake cycles. It achieves this through two interrelated aims: to use hierarchical linear models to measure dyadic interdependence in actigraphically recorded variables, and to investigate how much of this dyadic interdependence truly results from couple dynamics. The variables with the most significant couple interdependency were actual bed time, sleep latency, light/dark ratio, and wake bouts. The paper concludes by suggesting that interdependence may be the defining feature of couples' sleep, and that we need to employ analytic approaches that both acknowledge this and are sensitive to the possibilities that not all aspects of sleep will behave in the same way.     

The review of randomization in the Canadian National Breast Screening Study: Is the debate over?

The randomization procedure in the Canadian National Breast Screening Study (NBSS) is assessed in this issue (see pages 193 to 199) by Drs. John C. Bailar III and Brian MacMahon. They conclude that although there was ample opportunity for the randomization process to be subverted, no evidence of subversion was found. This is unlikely to allay all concerns about randomization, because there are still puzzling differences between the arms of the NBSS in a number of baseline variables. For example, the existence of prior health claims for breast cancer for women who entered the NBSS in Manitoba has raised the possibility that subversion occurred. Although the question may never be resolved, one lesion is clear: randomization in clinical trials should be managed in a manner that makes subversion impossible. As for the clinical implications of the NBSS for women in their 40s, physicians may now look to the results of randomized trials that have been published more recently. A meta-analysis of these results suggests that screening mammography reduces deaths from breast cancer among women in their 40s, but continued follow-up over the next few years will be needed to settle the debate.     

Complexation of the mycotoxin zearalenone with β-cyclodextrin: Study of the interaction and first promising applications

This work reports the study of the interactions between native and substituted β-cyclodextrins and zearalenone and its derivatives α- and β-zearelonol. The data obtained by fluorescence and NMR experiments suggested that zearalenone, α- and β-zearalenol and cyclodextrins give rise to host-guest complexation, with the inclusion of the phenolic moiety inside the cyclodextrin cavity. The high stability of these complexes induces a high fluorescence enhancement upon complexation. These results have been successfully applied to the spectrofluorimetric determination of zearalenone in maize raw samples, without any chromatographic separation. Presented at the 29^th Mykotoxin-Workshop, Fellbach, Germany, May 14–16, 2007 Financial support: Emilia-Romagna region (project SIQUAL)     

The transition from the native to the acid-state characterized by multi-spectroscopy approach: Study for the holo-form of bovine α-lactalbumin

The transition of the holo-form of bovine α-lactalbumin from the native (N) to the pH-generated acidic-state (A-state) was analyzed by probing its tertiary and secondary structure using a concerted spectroscopic approach combining near- and far-UV circular dichroism (CD), electrospray ionization ion mobility mass spectrometry (ESI-IM-MS), vibrational circular dichroism (VCD), and Fourier transform infrared spectroscopy (FTIR) in the attenuated total reflection (ATR) and transmission (TR) modes. The spectroscopic results, which relied on the interaction of an electromagnetic field with different molecular targets, confirmed the decay of extensive rigid side-chain packing interactions during the pH-induced N → A-state transition and revealed the targets' dependence on secondary structural changes. Independent analyses of the spectral changes using two methods of multivariate analysis, such as principal component analysis and two-dimensional correlation spectroscopy, revealed small but significant differences in the secondary structure as a result of the all-or-none transition. The cooperativity of the transition was quantitatively described using values corresponding to the mid-point (t_m) and width of the transition (Δt_m). The averages of the two parameters, calculated using the data collected by the different probes, were equal to 3.5 ± 0.2 and 0.6 ± 0.1(SE), respectively. The variable two-state nature of the cooperative N → A-state transition confirmed that the protonation of the side chain carboxyl groups on the Asp and Glu residues and that the release of a Ca^2 + ion induced structural changes on both the secondary and tertiary levels. The changes have been confirmed by results obtained from the concerted spectroscopic approach.     

Results of Observational Studies: Analysis of Findings from the Nurses’ Health Study

Background

The role of observational studies in informing clinical practice is debated, and high profile examples of discrepancies between the results of observational studies and randomised controlled trials (RCTs) have intensified that debate. We systematically reviewed findings from the Nurses’ Health Study (NHS), one of the longest and largest observational studies, to assess the number and strength of the associations reported and to determine if they have been confirmed in RCTs.

Methods

We reviewed NHS publication abstracts from 1978–2012, extracted information on associations tested, and graded the strength of the reported effect sizes. We searched PubMed for RCTs or systematic reviews for 3 health outcomes commonly reported in NHS publications: breast cancer, ischaemic heart disease (IHD) and osteoporosis. NHS results were compared with RCT results and deemed concordant when the difference in effect sizes between studies was ≤0.15.

Findings

2007 associations between health outcomes and independent variables were reported in 1053 abstracts. 58.0% (1165/2007) were statistically significant, and 22.2% (445/2007) were neutral (no association). Among the statistically significant results that reported a numeric odds ratio (OR) or relative risk (RR), 70.5% (706/1002) reported a weak association (OR/RR 0.5–2.0), 24.5% (246/1002) a moderate association (OR/RR 0.25–0.5 or 2.0–4.0) and 5.0% (50/1002) a strong association (OR/RR ≤0.25 or ≥4.0). 19 associations reported in NHS publications for breast cancer, IHD and osteoporosis have been tested in RCTs, and the concordance between NHS and RCT results was low (≤25%).

Conclusions

NHS publications contain a large number of analyses, the majority of which reported statistically significant but weak associations. Few of these associations have been tested in RCTs, and where they have, the agreement between NHS results and RCTs is poor.     

Study on the Effect of Kidney Transplantation on the Health of the Patients’ Offspring: A Report on 252 Chinese Children

Even though the incidence of pregnancies in the female recipients is lower and also chronic renal disease in male patients is associated with impaired spermatogenesis, the health of the children born to these patients was not studied. In this report, we discuss information on the growth and development of offspring of 248 male and female kidney recipient patients. Physical and routine clinical measurements of the 252 offspring (129 male and 123 female) born to these transplantation patients were made along with the intelligence tests. In some of these children chest X-ray and immune indices were assessed. Among the recipients, 219 males fathered 223 children with an average birth weight of 3,255 ± 374 g and 29 female recipients gave birth to 29 children with an average birth weight of 2,923 ± 551. While most of these children were normal, we noticed a case of soft double toe, a case of short tongue tie, five cases of marginal mental retardation, three cases of proteinuria, six cases of microscopic hematuria, 15 cases of low hemoglobin, and 21 cases with recurrent respiratory tract infections. We conclude that kidney transplantation has no significant impact on the growth, development, health, and intelligence of the offspring born to recipients.     

‘A Dispassionate and Objective Effort:’ Negotiating the First Study on the Biological Effects of Atomic Radiation

The National Academy of Science’s 1956 study on the Biological Effects of Atomic Radiation (BEAR) was designed to provide an objective analysis to assess conflicting statements by leading geneticists and by officials in the Atomic Energy Commission. Largely because of its status as a detached, non-governmental evaluation by eminent scientists, no studies have had a broader impact on the development of biological thinking in regard to nuclear policies. This paper demonstrates that despite the first BEAR study’s reputation as an objective and independent study, it was the product of careful negotiation between Academy scientists, the Atomic Energy Commission, and Britain’s Medical Research Council. This paper also reveals the fragility of the consensus that produced the Academy’s report, the range of political uses of the report, and the subsequent disaffection of the scientists who took part in it.     

β-Lactoglobulin's Conformational Requirements for Ligand Binding at the Calyx and the Dimer Interphase: a Flexible Docking Study

β-lactoglobulin (BLG) is an abundant milk protein relevant for industry and biotechnology, due significantly to its ability to bind a wide range of polar and apolar ligands. While hydrophobic ligand sites are known, sites for hydrophilic ligands such as the prevalent milk sugar, lactose, remain undetermined. Through the use of molecular docking we first, analyzed the known fatty acid binding sites in order to dissect their atomistic determinants and second, predicted the interaction sites for lactose with monomeric and dimeric BLG. We validated our approach against BLG structures co-crystallized with ligands and report a computational setup with a reduced number of flexible residues that is able to reproduce experimental results with high precision. Blind dockings with and without flexible side chains on BLG showed that: i) 13 experimentally-determined ligands fit the calyx requiring minimal movement of up to 7 residues out of the 23 that constitute this binding site. ii) Lactose does not bind the calyx despite conformational flexibility, but binds the dimer interface and an alternate Site C. iii) Results point to a probable lactolation site in the BLG dimer interface, at K141, consistent with previous biochemical findings. In contrast, no accessible lysines are found near Site C. iv) lactose forms hydrogen bonds with residues from both monomers stabilizing the dimer through a claw-like structure. Overall, these results improve our understanding of BLG''s binding sites, importantly narrowing down the calyx residues that control ligand binding. Moreover, our results emphasize the importance of the dimer interface as an insufficiently explored, biologically relevant binding site of particular importance for hydrophilic ligands. Furthermore our analyses suggest that BLG is a robust scaffold for multiple ligand-binding, suitable for protein design, and advance our molecular understanding of its ligand sites to a point that allows manipulation to control binding.     

FRAX?: Prediction of Major Osteoporotic Fractures in Women from the General Population: The OPUS Study

Purposes

The aim of this study was to analyse how well FRAX® predicts the risk of major osteoporotic and vertebral fractures over 6 years in postmenopausal women from general population.

Patients and methods

The OPUS study was conducted in European women aged above 55 years, recruited in 5 centers from random population samples and followed over 6 years. The population for this study consisted of 1748 women (mean age 74.2 years) with information on incident fractures. 742 (43.1%) had a prevalent fracture; 769 (44%) and 155 (8.9%) of them received an antiosteoporotic treatment before and during the study respectively. We compared FRAX® performance with and without bone mineral density (BMD) using receiver operator characteristic (ROC) c-statistical analysis with ORs and areas under receiver operating characteristics curves (AUCs) and net reclassification improvement (NRI).

Results

85 (4.9%) patients had incident major fractures over 6 years. FRAX® with and without BMD predicted these fractures with an AUC of 0.66 and 0.62 respectively. The AUC were 0.60, 0.66, 0.69 for history of low trauma fracture alone, age and femoral neck (FN) BMD and combination of the 3 clinical risk factors, respectively. FRAX® with and without BMD predicted incident radiographic vertebral fracture (n = 65) with an AUC of 0.67 and 0.65 respectively. NRI analysis showed a significant improvement in risk assignment when BMD is added to FRAX®.

Conclusions

This study shows that FRAX® with BMD and to a lesser extent also without FN BMD predict major osteoporotic and vertebral fractures in the general population.     

Diabetes Mellitus and the Risk of Alzheimer’s Disease: A Nationwide Population-Based Study

Objectives

Possible association between diabetes mellitus (DM) and Alzheimer’s disease (AD) has been controversial. This study used a nationwide population-based dataset to investigate the relationship between DM and subsequent AD incidence.

Methods

Data were collected from Taiwan’s National Health Insurance Research Database, which released a cohort dataset of 1,000,000 randomly sampled people and confirmed it to be representative of the Taiwanese population. We identified 71,433 patients newly diagnosed with diabetes (age 58.74±14.02 years) since January 1997. Using propensity score, we matched them with 71,311 non-diabetic subjects by time of enrollment, age, gender, hypertension, hyperlipidemia, and previous stroke history. All the patients were followed up to December 31, 2007. The endpoint of the study was occurrence of AD.

Results

Over a maximum 11 years of follow-up, diabetic patients experienced a higher incidence of AD than non-diabetic subjects (0.48% vs. 0.37%, p<0.001). After Cox proportional hazard regression model analysis, DM (hazard ratio [HR], 1.76; 95% confidence interval [CI], 1.50–2.07, p<0.001), age (HR, 1.11; 95% CI, 1.10–1.12, p<0.001), female gender (HR, 1.24; 95% CI, 1.06–1.46, p = 0.008), hypertension (HR, 1.30; 95% CI, 1.07–1.59, p = 0.01), previous stroke history (HR, 1.79; 95% CI, 1.28–2.50, p<0.001), and urbanization status (metropolis, HR, 1.32; 95% CI, 1.07–1.63, p = 0.009) were independently associated with the increased risk of AD. Neither monotherapy nor combination therapy with oral antidiabetic medications were associated with the risk of AD after adjusting for underlying risk factors and the duration of DM since diagnosis. However, combination therapy with insulin was found to be associated with greater risk of AD (HR, 2.17; 95% CI, 1.04–4.52, p = 0.039).

Conclusion

Newly diagnosed DM was associated with increased risk of AD. Use of hypoglycemic agents did not ameliorate the risk.     

Infective Endocarditis in the U.S., 1998–2009: A Nationwide Study

Background

Previous studies based on local case series estimated the annual incidence of endocarditis in the U.S. at about 4 per 100,000 population. Small-scale studies elsewhere have reported similar incidence rates. However, no nationally-representative population-based studies have verified these estimates.

Methods and Findings

Using the 1998–2009 Nationwide Inpatient Sample, which provides diagnoses from about 8 million U.S. hospitalizations annually, we examined endocarditis hospitalizations, bacteriology, co-morbidities, outcomes and costs. Hospital admissions for endocarditis rose from 25,511 in 1998 to 38, 976 in 2009 (12.7 per 100,000 population in 2009). The age-adjusted endocarditis admission rate increased 2.4% annually. The proportion of patients with intra-cardiac devices rose from 13.3% to 18.9%, while the share with drug use and/or HIV fell. Mortality remained stable at about 14.5%, as did cardiac valve replacement (9.6%). Other serious complications increased; 13.3% of patients in 2009 suffered a stroke or CNS infection, and 5.5% suffered myocardial infarction. Amongst cases with identified pathogens, Staphylococcus aureus was the most common, increasing from 37.6% in 1998 to 49.3% in 2009, 53.3% of which were MRSA. Streptococci were mentioned in 24.7% of cases, gram-negatives in 5.6% and Candida species in 1.0%. We detected no inflection in hospitalization rates after changes in prophylaxis recommendations in 2007. Mean age rose from 58.6 to 60.8 years; elderly patients suffered higher rates of myocardial infarction and death, but slightly lower rates of Staphylococcus aureus infections and neurologic complications. Our study relied on clinically diagnosed cases of endocarditis that may not meet strict criteria. Moreover, since some patients are discharged and readmitted during a single episode of endocarditis, our hospitalization figures probably slightly overstate the true incidence of this illness.

Conclusions

Endocarditis is more common in the U.S. than previously believed, and is steadily increasing. Preventive efforts should focus on device-associated and health-care-associated infections.     

Severe Maternal Sepsis in the UK, 2011–2012: A National Case-Control Study

Background

In light of increasing rates and severity of sepsis worldwide, this study aimed to estimate the incidence of, and describe the causative organisms, sources of infection, and risk factors for, severe maternal sepsis in the UK.

Methods and Findings

A prospective case-control study included 365 confirmed cases of severe maternal sepsis and 757 controls from all UK obstetrician-led maternity units from June 1, 2011, to May 31, 2012. Incidence of severe sepsis was 4.7 (95% CI 4.2–5.2) per 10,000 maternities; 71 (19.5%) women developed septic shock; and five (1.4%) women died. Genital tract infection (31.0%) and the organism Escherichia coli (21.1%) were most common. Women had significantly increased adjusted odds ratios (aORs) of severe sepsis if they were black or other ethnic minority (aOR = 1.82; 95% CI 1.82–2.51), were primiparous (aOR = 1.60; 95% CI 1.17–2.20), had a pre-existing medical problem (aOR = 1.40; 95% CI 1.01–1.94), had febrile illness or were taking antibiotics in the 2 wk prior to presentation (aOR = 12.07; 95% CI 8.11–17.97), or had an operative vaginal delivery (aOR = 2.49; 95% CI 1.32–4.70), pre-labour cesarean (aOR = 3.83; 95% CI 2.24–6.56), or cesarean after labour onset (aOR = 8.06; 95% CI 4.65–13.97). Median time between delivery and sepsis was 3 d (interquartile range = 1–7 d). Multiple pregnancy (aOR = 5.75; 95% CI 1.54–21.45) and infection with group A streptococcus (aOR = 4.84; 2.17–10.78) were associated with progression to septic shock; for 16 (50%) women with a group A streptococcal infection there was <2 h—and for 24 (75%) women, <9 h—between the first sign of systemic inflammatory response syndrome and a diagnosis of severe sepsis. A limitation of this study was the proportion of women with sepsis without an identified organism or infection source (16.4%).

Conclusions

For each maternal sepsis death, approximately 50 women have life-threatening morbidity from sepsis. Follow-up to ensure infection is eradicated is important. The rapid progression to severe sepsis highlights the importance of following the international Surviving Sepsis Campaign guideline of early administration of high-dose intravenous antibiotics within 1 h of admission to hospital for anyone with suspected sepsis. Signs of severe sepsis in peripartum women, particularly with confirmed or suspected group A streptococcal infection, should be regarded as an obstetric emergency. Please see later in the article for the Editors'' Summary