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Wearable physical activity (PA) monitors have improved the ability to estimate free-living total energy expenditure (TEE) but their application during arduous military training alongside more well-established research methods has not been widely documented. This study aimed to assess the validity of two wrist-worn activity monitors and a PA log against doubly-labelled water (DLW) during British Army Officer Cadet (OC) training. For 10 days of training, twenty (10 male and 10 female) OCs (mean ± SD: age 23 ± 2 years, height 1.74 ± 0.09 m, body mass 77.0 ± 9.3 kg) wore one research-grade accelerometer (GENEActiv, Cambridge, UK) on the dominant wrist, wore one commercially-available monitor (Fitbit SURGE, USA) on the non-dominant wrist and completed a self-report PA log. Immediately prior to this 10-day period, participants consumed a bolus of DLW and provided daily urine samples, which were analysed by mass spectrometry to determine TEE. Bivariate correlations and limits of agreement (LoA) were employed to compare TEE from each estimation method to DLW. Average daily TEE from DLW was 4112 ± 652 kcal·day against which the GENEActiv showed near identical average TEE (mean bias ± LoA: -15 ± 851 kcal day ) while Fitbit tended to underestimate (-656 ± 683 kcal·day ) and the PA log substantially overestimate (+1946 ± 1637 kcal·day ). Wearable physical activity monitors provide a cheaper and more practical method for estimating free-living TEE than DLW in military settings. The GENEActiv accelerometer demonstrated good validity for assessing daily TEE and would appear suitable for use in large-scale, longitudinal military studies.

Objective To estimate the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies in health care personnel. Methods The Mayo Clinic Serology Screening Program was created to provide a voluntary, two-stage testing program for SARS-CoV-2 antibodies to health care personnel. The first stage used a dried blood spot screening test initiated on June 15, 2020. Those participants identified as reactive were advised to have confirmatory testing via a venipuncture. Venipuncture results through August 8, 2020, were considered. Consent and authorization for testing was required to participate in the screening program. This report, which was conducted under an institutional review board–approved protocol, only includes employees who have further authorized their records for use in research. Results A total of 81,113 health care personnel were eligible for the program, and of these 29,606 participated in the screening program. A total of 4284 (14.5%) of the dried blood spot test results were "reactive" and warranted confirmatory testing. Confirmatory testing was completed on 4094 (95.6%) of the screen reactive with an overall seroprevalence rate of 0.60% (95% CI, 0.52% to 0.69%). Significant variation in seroprevalence was observed by region of the country and age group. Conclusion The seroprevalence for SARS-CoV-2 antibodies through August 8, 2020, was found to be lower than previously reported in other health care organizations. There was an observation that seroprevalence may be associated with community disease burden.

BACKGROUND Dietary changes have led to the growing prevalence of type 2 diabetes and nonalcoholic fatty liver disease. A hallmark of both disorders is hepatic lipid accumulation, derived in part from increased de novo lipogenesis. Despite the popularity of high-protein diets for weight loss, the effect of dietary protein on de novo lipogenesis is poorly studied. We aimed to characterize the effect of dietary protein on de novo lipid synthesis. METHODS We use a 3-way crossover interventional study in healthy males to determine the effect of high-protein feeding on de novo lipogenesis, combined with in vitro models to determine the lipogenic effects of specific amino acids. The primary outcome was a change in de novo lipogenesis–associated triglycerides in response to protein feeding. RESULTS We demonstrate that high-protein feeding, rich in glutamate, increases de novo lipogenesis–associated triglycerides in plasma (1.5-fold compared with control; P < 0.0001) and liver-derived very low-density lipoprotein particles (1.8-fold; P < 0.0001) in samples from human subjects (n = 9 per group). In hepatocytes, we show that glutamate-derived carbon is incorporated into triglycerides via palmitate. In addition, supplementation with glutamate, glutamine, and leucine, but not lysine, increased triglyceride synthesis and decreased glucose uptake. Glutamate, glutamine, and leucine increased activation of protein kinase B, suggesting that induction of de novo lipogenesis occurs via the insulin signaling cascade. CONCLUSION These findings provide mechanistic insight into how select amino acids induce de novo lipogenesis and insulin resistance, suggesting that high-protein feeding to tackle diabetes and obesity requires greater consideration. FUNDING The research was supported by UK Medical Research Council grants MR/P011705/1, MC_UP_A090_1006 and MR/P01836X/1. JLG is supported by the Imperial Biomedical Research Centre, National Institute for Health Research (NIHR)., A subset of amino acids may induce de novo lipogenesis in humans, suggesting that use of high-protein diets to tackle diabetes requires greater consideration.

The number of chemicals in our society and in our daily lives continues to increase. Accompanying this is an increasing risk of human exposure to and injury from hazardous substances. Chemical hazards can range from those present in industrial manufacturing processes, to those under the kitchen sink of the average household. Performing regular, structured surveillance of chemical exposures and events allows a greater situational awareness with respect to the common chemical hazards causing injury and the frequency of their occurrence as well as providing a better understanding of exposures. This information can be used to introduce measures to better protect public health from hazardous chemical exposures. This chapter aims to give an overview of surveillance for chemical events, including some of the sources which may be used, examples of the types of chemicals involved in exposures and the rationale for conducting regular surveillance and implementing a structured surveillance strategy.

A number of European and international IT platforms are used to notify competent authorities of new potential chemical exposures. Recently the European Parliament and the Council of European Union adopted new legislation that aims to improve the co-ordinated response to cross border health threats (Decision 1082/2013/EU). The Decision, inter alia, sets provisions on notification, ad hoc monitoring and coordination of public health measures following serious cross border threats to health from biological, chemical and environmental events as well as events that have an unknown origin. The legal instrument applies to all European Union Member States and is comparable to the International Health Regulations in its content, requirements and adoption of a multiple hazards approach. An inter-sectoral and multidisciplinary response to events with potentially dangerous cross border exposure pathways is often required. For example, European Poisons Centres may be aware of cases of toxic exposure to a product and, in parallel, trading standards may be aware of the same product due to a breach of consumer product standards. Whilst both cases would have been recorded for separate purposes in different alerting systems, they relate to the same exposure pathway; therefore a process for linking these records would allow a more robust approach to risk assessment and risk mitigation. The Decision seeks to reconcile this issue for serious threats by linking relevant platforms into one overarching higher level risk management IT platform called the Early Warning Response System (EWRS). This system will serve to link other sectors within the European Commission (EC) to public health (e.g. medicines), as well as other EU agencies and international bodies via co-notification features. Other European alert systems will be linked to EWRS to facilitate information sharing at both the assessment and management levels. This paper provides a timely overview of the main systems run by the EC and other international organisations that provide alerts following chemical incidents that have, or may have, the potential to affect public health. The advantages and further considerations of linking these different systems and sectors are also highlighted. Recommendations are made with the purpose of ensuring that modifications to these systems made to satisfy with EU legislation enable a more timely coordinated response and greater awareness of events in Europe, thereby reducing the public health impact from chemical exposures. Keywords: Chemicals, Hazards, Reporting, Alerting, RASCHEM, EWRS

The European Union (EU) Decision (1082/2013/EU) on serious cross border threats to health was adopted by the European Parliament in November 2013, in recognition of the need to strengthen the capacity of Member States to coordinate the public health response to cross border threats, whether from biological, chemical, environmental events or events which have an unknown origin. Although mechanisms have been in place for years for reporting cross border health threats from communicable diseases, this has not been the case for incidents involving chemicals and/or environmental events. A variety of collaborative EU projects have been funded over the past 10 years through the Health Programme to address gaps in knowledge on health security and to improve resilience and response to major incidents involving chemicals. This paper looks at the EU Health Programme that underpins recent research activities to address gaps in resilience, planning, responding to and recovering from a cross border chemical incident. It also looks at how the outputs from the research programme will contribute to improving public health management of transnational incidents that have the potential to overwhelm national capabilities, putting this into context with the new requirements as the Decision on serious cross border threats to health as well as highlighting areas for future development. Keywords: Chemical incident, Public health risk assessment and management, Cross border health threats, CBRN, Emergency response, Alerting and notification

Summary To test the hypothesis that competitor density and time spent at a food resource influences aggressive behaviour in male swordtail, Xiphophorus sp., fish were kept at two densities (low: 18 fish m−3; high: 54 fish m−3) and aggressive behaviour was recorded with the time at the food resource used as a covariate. Competitor density is likely to affect the cost:benefit ratio of food defence. When density is low, there should be sufficient food for all individuals and intra-specific interactions are expected to be rare, while at high densities, increased intra-specific encounter rates mean that individuals may spend more time defending a resource than utilising it. Food resource defence should occur at intermediate densities. The frequency of aggression, i.e. bites, chases, and display behaviour was significantly positively influenced by time spent at the food resource (Bites: F1,31 = 8.186, P = 0.007; Chases: F1,31 = 6.439, P = 0.016; Displays: F1,31 = 4.435, P = 0.043) suggesting that food resource defence occurred. Competitor density had no effect on food resource defence and minimal effect on the frequency of aggression with only one type of aggressive behaviour, male–male displays, showing a difference between densities (F1,31 = 6.975, P = 0.013). This finding is suggested to be a result of the formation of dominance hierarchies in this species. Aggression from the dominant individual may be directed at only subordinates of the next dominance rank and subordinate behaviour may be restricted by status rather than immediate threat. In such a situation, aggression may be independent of competitor density.

1. Developing tail tendons from rats (19-day foetal to 126 days post partum) were examined by electron microscopy after staining for proteoglycan with a cationic copper phthalocyanin dye. Cuprolinic Blue, in a “critical electrolyte concentration” method. Hydroxyproline was measured on papain digests of tendons, from which glycosaminoglycuronans were isolated, characterized and quantified. 2. Mean collagen fibril diameters increased more than 10-fold with age according to a sigmoid curve, the rapid growth phase 2 being during 30-90 days after conception. Fibril periodicities were considerably smaller (50-55 nm) in phases 1 and 2 than in phase 3 (greater than 62 nm). 3. Dermatan sulphate is the main glycosaminoglycuronan in mature tendon. Chondroitin sulphate and hyaluronate preponderate in foetal tissue. 4. Proteoglycan was seen around but not inside collagen fibrils. Proteoglycan and collagen were quantified from electron micrographs. Their ratios behaved similarly to uronic acid/hydroxyproline and hyaluronate/hydroxyproline ratios, which decreased rapidly around birth, and then levelled off to a low plateau coincident with the onset of rapid growth in collagen fibril diameter. 5. Dermatan sulphate/hydroxyproline ratios suggest that the proteoglycan orthogonal array around the fibril is largely dermatan sulphate. In the foetus hyaluronate and chondroitin sulphate exceed that expected to be bound to collagen. 6. An inhibiting action of chondroitin sulphate-rich proteoglycan on fibril diameter growth is suggested. 7. The distributions of hyaluronate, chondroitin sulphate and dermatan sulphate are discussed in the light of secondary structures suggested to be present in hyaluronate and chondroitin sulphate, but not in dermatan sulphate.

The left stifle joints of 16 beagle dogs were subjected to surgical division of the anterior cruciate ligament (ACL). The femoral condyles showed surface alterations and damage after 14 days when examined by low temperature (LTSEM) and conventional scanning electron microscopy (SEM). The first change was an increase in the fibrous texture of the articular cartilage surface. Folds and surface roughening were later recognised. After 112 days deformation and disruption gave way to cracking or fracture of the surface layers. Superficial damage was focal in distribution and accompanied by a decrease in the frequency of tertiary elevations. The affected areas of cartilage increased in frequency and size with time and surgery. The observations obtained from LTSEM, in which the tissue remains fully hydrated during examination, may be caused by alterations in water content and a loss of proteoglycan at the surface, together with changes in cell shape and size. Surface cracks may be the en face appearance of histological fibrillation.

Thin (100 micron) perpendicular slices of canine femoral condylar cartilage were placed horizontally on the stage of a Nachet microscope and viewed by transmitted light in the differential interference contrast mode. Each slice was held on the microscope stage by a loading rig and tested mechanically in compression. Measured loads to a maximum of approximately 2-3 MN/m2 were applied to the end of the slice corresponding to the articular surface. Photographs were taken of the cartilage before and during loading, and the distance by which selected chondrocytes were displaced was used as an index of mechanical strain, i.e., of change in length/original length. Maximum strains were observed in the superficial cartilage zone. Minimum strains were recorded in the mid-zone, at a depth corresponding to approximately 75% of the total cartilage thickness. The relative concentrations of cartilage collagen (COL) and proteoglycan (PG) were assessed by the light and electron microscopic histochemical study of cartilage sections taken from contiguous blocks. Superficial cartilage, which deformed most, had high concentrations of oriented COL fibres, low concentrations of PG. Mid-zone cartilage, which deformed least, had lower concentrations of randomly arrayed COL fibres but relatively high concentrations of PG.

Two collagen-poor, ultramicroscopic layers are described at the surface of canine articular cartilage. They are distinguished by staining with an electron-dense cationic dye, Cupromeronic Blue, in a critical electrolyte concentration technique and by digestion with testicular hyaluronidase. The superficial layer, approximately 50 nm thick, stained at low electrolyte concentrations but failed to stain in conditions specific for sulphated glycosaminoglycans. It was hyaluronidase-resistant and may be either glycoprotein or protein in nature. The deeper layer, 100-400 nm thick, stained positively at electrolyte concentrations specific for sulphated glycosaminoglycans but not in conditions specific for keratan sulphate. It was removed by hyaluronidase digestion. This layer probably represents a chondroitin sulphate-rich proteoglycan. These surface layers may be important in the lubrication of the articular surface and in the permeability and compression resistance of the superficial cartilage zone.

Seven young men developed acute pulmonary hemorrhage and edema from the inhalation of powder or fumes of a bisphenol epoxy resin containing tri-mellitic anhydride (TMA) while working in a steel pipe-coating plant. The illness was characterized by cough, hemoptysis, dyspnea, fever, weakness and nausea or vomiting. Chest roentgenograms showed either a bilateral or unilateral pulmonary infiltrate. All patients had a normochromic type of anemia. Pulmonary function studies demonstrated a restrictive defect, hypoxemia, and increased A-a DO2 gradients. Light and electron microscopic studies of lung tissue revealed extensive bleeding into alveoli but no basement membrane deposits were seen and no antiglomerular basement membrane antibodies were detected. The patients improved quickly without treatment. Follow-up studies of six patients three weeks to one year after their illness revealed apparent recovery. A detailed medical survey carried out on all 29 workers currently employed in the plant revealed five additional men had experienced severe recurrent pulmonary problems.

Researchers conducted an epidemiologic investigation of an outbreak of brucellosis at a meat-packing plant, where work was interrupted by a strike. The investigation revealed that the risk of infection with brucellosis may coincide with the rate at which reactor cattle are slaughtered, a factor often overlooked in other reports which investigated outbreaks of brucellosis. The slaughter of 20 to 25 reactor cattle per day was the estimate of the critical number of reactor cattle when the risk of infection is most likely to occur. Of the 193 workers studied, 17 (8.8%) were seropositive, but only eight (4.1%) were presumptive cases. Young, newly employed workers who did not wear glasses were at greatest risk of infection.

Following the report of ten cases of respiratory illness in processors of frozen king crab, we investigated the conditions of work and the pulmonary and immunologic status of the workers in three crab-processing and one fish-packing (control) plant. Pulmonary function was measured before and after work, and skin tests were performed in subgroups matched for age, sex, and duration of current employment. The antibody response to king crab antigens was examined in sera from the subgroups and another (unrelated) control group. Extracts of crab meat, shell, and processing dust were used for skin testing and precipitin detection. FEV1, FVC, and MEFR decreased during the day in two crab processors, and precipitins were evident in sera from nine, but findings were normal in the fish packers. Crab meat elicited the strongest response, with multiple precipitin bands in some cases. Control sera showed no reaction. There was correlation between serology, results of skin tests, and symptoms. It is concluded that the inhalation of aerosolized crab antigen(s) may cause respiratory symptoms and can cause immunologic effects similar to those caused by other occupational respiratory allergens. We recommend preplacement and periodic medical examination of workers in crab-processing plants, improved ventilation in processing areas, and programs to discourage smoking.

Rat tail tendon was stained with a cationic phthalocyanin dye, Cupromeronic Blue, in a ‘critical-electrolyte-concentration’ method [Scott (1980) Biochem. J. 187, 887-891] specifically to demonstrate proteoglycan by electron microscopy. Hyaluronidase digestion in the presence of proteinase inhibitors corroborated the results. Collagen was stained with uranyl acetate and/or phosphotungstic acid to demonstrate the banding pattern a-e in the D period. Proteoglycan was distributed about the collagen fibrils in an orthogonal array, the transverse elements of which were located almost exclusively at the d band, in the gap zone. The proteoglycan may inhibit (1) fibril radial growth by accretion of collagen molecules or fibril fusion, through interference with cross-linking, and (2) calcification by occupying the holes in the gap region later to be filled with hydroxyapatite.

Summary. Spirochaetes were recognised in the large bowel of 57 of 59 baboons as a basophilic fringe at the microvillous brush border of the epithelial cells. Both caecum and colon were usually affected, but seven animals had spirochaetes in the caecum alone. Examination of three animals by transmission electronmicroscopy revealed only one type of spirochaete; ring forms and cross-walls were present. Inflammatory changes were not seen in association with the infection, and the distribution of spirochaetes in 10 animals with soft or diarrhoeic faeces resembled that in normal animals.

Blocks of hyaline cartilage from the femoral condyles of five young adult beagles dogs were quench-frozen in nitrogen slush at 63 K. The free cartilage surfaces of blocks from three animals were examined in the secondary electron mode; the remaining specimens were cut by cryoultramicrotone (approximately 188 K) tangential to the surface to expose midzone cartilage which was examined in the backscattered electron mode. A random array of gently convex prominences was apparent at the free cartilage surfaces. When X-ray emissions were recorded from tissue immediately below these elevations, the spectra proved to be similar to those derived from midzone chondrocytes. These spectra revealed high count rates for the X-rays characteristic of P and K. By contrast, in areas of free surface remote from these prominences, and in midzone intercellular matrix, larger count rates for the X-rays characteristic of Na, S. Cl and Ca were detected. The evidence supports the hypothesis that the elevations seen on the non-loaded articular cartilage of disarticulated mammalian synovial joints are the surface representations of superficial chondrocytes.

A scanning electron microscopic technique for the examination of bulk, fresh, hydrated human tissue is described. Samples of fresh tissue are frozen in liquid nitrogen against a mirror-finished copper block and planed in a cryoultramicrotome before transfer to a low temperature scanning electron microscope. After sublimation of water from the specimen surface, the tissue is examined in secondary electron and backscattered electron modes. Adjacent pieces of tissue, and those retrieved after backscattered electron observation, can be readily prepared for and examined by light and by conventional transmission electron microscopy. The method has been tested with multiple blocks taken from 6 cases of human breast carcinoma. In the backscattered electron mode, the infiltrating columns of neoplastic cells can be distinguished from mammary adipose and fibrous tissue. Within a carcinoma, the collagenous stroma, carcinoma cells, and perivascular and perineural infiltrates can be identified. These features have been contrasted with those obtained by light microscopy, by low temperature scanning, and by transmission electron microscopy. This use of backscattered electron imaging for the investigation of unfixed hydrated tissue offers the possibility that the technique could be of considerable value in the microscopy of very small samples in which, because of a need for subsequent biochemical, histochemical, and immunologic investigation, fixation and dehydration are to be avoided.