Distribution and abundance of microplastics in coastal sediments depends on grain size and distance from sources.

Microplastic deposition in marine sediments is a geographically widespread problem. This study examines microplastics in intertidal and subtidal sediments at 87 locations in habitats designated as Special Areas of Conservation (SACs) and Special Protection Areas (SPAs) on the coastline of Ireland. Established methodological approaches including, organic matter digestion, density separation, particle extraction and polymer identification were applied. Microplastic abundance was closely related with distance from known sources and concentrations were greater in intertidal as opposed to subtidal sediments. Colourless, polyethylene fibres and polypropylene fragments were the most abundant MP recorded and finer grained sediments were shown to entrap more MPs than coarser sediments. The results demonstrate that an understanding of potential sources of pollution, sediment type and hydrodynamic conditions are very important in terms of MP abundance and distribution in marine sediments and also in terms of effective waste management strategies and policy aimed at reducing the global plastics problem.

Cellular events of acute, resolving or progressive COVID-19 in SARS-CoV-2 infected non-human primates.

Understanding SARS-CoV-2 associated immune pathology is crucial to develop pan-effective vaccines and treatments. Here we investigate the immune events from the acute state up to four weeks post SARS-CoV-2 infection, in non-human primates (NHP) with heterogeneous pulmonary pathology. We show a robust migration of CD16 expressing monocytes to the lungs occurring during the acute phase, and we describe two subsets of interstitial macrophages (HLA-DR+CD206-): a transitional CD11c+CD16+ cell population directly associated with IL-6 levels in plasma, and a long-lasting CD11b+CD16+ cell population. Trafficking of monocytes is mediated by TARC (CCL17) and associates with viral load measured in bronchial brushes. We also describe associations between disease outcomes and high levels of cell infiltration in lungs including CD11b+CD16hi macrophages and CD11b+ neutrophils. Accumulation of macrophages is long-lasting and detectable even in animals with mild or no signs of disease. Interestingly, animals with anti-inflammatory responses including high IL-10:IL-6 and kynurenine to tryptophan ratios show less severe illness. Our results unravel cellular mechanisms of COVID-19 and suggest that NHP may be appropriate models to test immune therapies.

Bayesian techniques for comparison of the test performance of PCR and culture for the identification of Campylobacter in enriched comminuted chicken samples.

AIMS: Using Bayesian methods that do not require the definition of a gold standard, the diagnostic sensitivity and specificity of a real-time polymerase chain reaction (PCR) assay are compared to those of an enriched culture assay for detection of Campylobacter in enriched comminuted chicken samples. METHODS AND RESULTS: Food Safety and Inspection Service comminuted chicken samples were collected from production facilities across the United States. Enriched samples were examined using a commercial real-time PCR kit and plated for culture. Allowing for conditional dependence between these approaches and defining relatively uninformed prior distributions, the 'no gold standard' Bayesian methods generated estimates of the means (95% credible interval) of the posterior distributions for sensitivity and specificity of the PCR as 93% (79, 100%) and 95% (87, 100%) respectively. The estimated sensitivity implies a mean false negative frequency of 7%. The estimated means of the posterior distributions for sensitivity and specificity of the culture assay were 91% (76, 100%) and 96% (88, 100%) respectively. In this case, the mean false negative frequency is 9%. Graphical comparisons of the posterior distributions with their corresponding prior distributions suggested only subtle differences in the sensitivities of both tests, but the posterior distributions for specificities are substantially more certain than the prior distributions. CONCLUSIONS: The study suggests that the commercial real-time PCR assay is a more sensitive screening test that would provide timelier negative test results. The modest 1% reduction in specificity of this PCR assay, as compared to an enriched culture assay, is less of a concern for regulatory testing programs if a culture-based confirmatory assay is applied to all presumptive positive samples. SIGNIFICANCE AND IMPACT OF THE STUDY: The sensitivity and specificity of a PCR assay and a culture assay for Campylobacter in comminuted poultry produced in the United States were estimated. The PCR assay was shown to be an appropriate alternative screening test.

Time valuation of historical outbreak attribution data.

Human illness attribution is recognized as an important metric for prioritizing and informing food-safety decisions and for monitoring progress towards long-term food-safety goals. Inferences regarding the proportion of illnesses attributed to a specific commodity class are often based on analyses of datasets describing the number of outbreaks in a given year or combination of years. In many countries, the total number of pathogen-related outbreaks reported nationwide for an implicated food source is often fewer than 50 instances in a given year and the number of years for which data are available can be fewer than 10. Therefore, a high degree of uncertainty is associated with the estimated fraction of pathogen-related outbreaks attributed to a general food commodity. Although it is possible to make inferences using only data from the most recent year, this type of estimation strategy ignores the data collected in previous years. Thus, a strong argument exists for an estimator that could 'borrow strength' from data collected in the previous years by combining the current data with the data from previous years. While many estimators exist for combining multiple years of data, most either require more data than is currently available or lack an objective and biologically plausible theoretical basis. This study introduces an estimation strategy that progressively reduces the influence of data collected in past years in accordance with the degree of departure from a Poisson process. The methodology is applied to the estimation of the attribution fraction for Salmonella and Escherichia coli O157:H7 for common food commodities and the estimates are compared against two alternative estimators.

The difference in seizure incidences between young and adult rats related to lipid peroxidation after intracortical injection of ferric chloride.

INTRODUCTION: Clinical studies have shown that the incidence of early post-traumatic seizures is higher in children than in adults. It has been proposed that iron-induced lipid peroxidation plays an important role in the development of epileptogenic foci. This study examined some of the hypothesised reasons for the difference in the incidence of early post-traumatic seizures between children and adults. METHODS: 12 young rats and 12 adult rats were randomised into four groups. Groups 1 and 2 were control groups, comprising six young rats and six adult rats, respectively, and they were administered an intracortical injection of saline. Groups 3 and 4 were injury groups, comprising six young rats and six adult rats, respectively, and they were administered an intracortical injection of FeCl3. All the rats were observed for six hours post-injection for the occurrence of seizures, and were then killed. The injected hemispheres were extirpated and tested for the malondialdehyde (MDA) levels and superoxide dismutase (SOD) activity as indices of oxidative damage. RESULTS: Seizures were observed only in Group 3. Increased MDA levels and decreased SOD activity were observed in Group 3 (ANOVA, p-value is less than 0.001). Increased MDA levels and decreased SOD activity were significantly higher in rats with seizures (Group 3) than in those without seizures (independent t-test, p-value is less than 0.001). CONCLUSION: Different levels of lipid peroxidation induced by an intracortical ferric chloride injection may account for the different incidence rates of seizures between young and adult rats.

Concentrations of metals in blood and feathers of nestling ospreys (Pandion haliaetus) in Chesapeake and Delaware Bays.

In 2000, 2001, and 2002, blood and feather samples were collected from 40-45-day-old nestling ospreys (Pandion haliaetus) from Chesapeake Bay and Delaware Bay and River. Concentrations of 18 metals, metalloids, and other elements were determined in these samples by inductively coupled plasma-mass spectroscopy, and Hg concentrations were measured by cold vapor atomic absorption spectroscopy. When compared to concurrent reference areas (South, West, and Rhode Rivers), mean As and Hg concentrations in blood were greater (p < 0.05) in two of three Chesapeake Bay regions of concern (Baltimore Harbor [As: 1.18 vs. 0.548 microg/g dw], Anacostia River [Hg: 0.305 vs. 0.178 microg/g dw], and Elizabeth River [As: 0.876 vs. 0.663 microg/g dw; Hg: 0.260 vs. 0.180 microg/g dw]). Lead was detected more frequently in blood of nestlings from the highly industrialized Elizabeth River compared to the rural reference area. When compared to the concurrent reference area, mean Al, Ba, Hg, Mn, and Pb concentrations in feathers were substantially greater (p < 0.05) in one or more Chesapeake regions of concern (Anacostia River [Al: 206 vs. 62.1 microg/g dw; Ba: 3.31 vs. 0.823 microg/g dw; Mn: 65.4 vs. 22.9 microg/g dw] and Elizabeth River [Al: 165 vs. 63.5 microg/g dw; Hg: 1.24 vs. 0.599 microg/g dw; Pb 1.47 vs. 0.543 microg/g dw]). When compared to the coastal Inland Bays reference area, feathers of nestlings from northern Delaware Bay and River had greater concentrations (p < 0.05) of Ba (1.90 vs. 0.660 microg/g dw), Fe (258 vs. 109 microg/g dw), Mn (18.5 vs. 4.66 microg/g dw), Mo (0.130 vs. 0.040 microg/g dw), Pb (1.96 vs. 0.624 microg/g dw), and V (0.671 vs. 0.325 microg/g dw), presumably due to extensive metal-working and petroleum refinery activities. Concentrations of Hg in nestling feathers from Delaware were frequently greater than in the Chesapeake. The present findings and those of related reproductive studies suggest that concentrations of several heavy metals (e.g., Cd, Hg, Pb) in nestling blood and feathers from Chesapeake and Delaware Bays were below toxicity thresholds and do not seem to be affecting chick survival during the nestling period.

Retrospective ecotoxicological data and current information needs for terrestrial vertebrates residing in coastal habitat of the United States.

The Contaminant Exposure and Effects-Terrestrial Vertebrates (CEE-TV) database was developed to conduct simple searches for ecotoxicological information, examine exposure trends, and identify significant data gaps. The CEE-TV database contains 16,696 data records on free-ranging amphibians, reptiles, birds, and mammals residing in estuarine and coastal habitats of the Atlantic, Gulf, and Pacific coasts, Alaska, Hawaii, and the Great Lakes. Information in the database was derived from over 1800 source documents, representing 483 unique species (about 252,000 individuals), with sample collection dates spanning from 1884 to 2003. The majority of the records contain exposure data (generally contaminant concentrations) on a limited number (n = 209) of chlorinated and brominated compounds, cholinesterase-inhibiting pesticides, economic poisons, metals, and petroleum hydrocarbons, whereas only 9.3% of the records contain biomarker or bioindicator effects data. Temporal examination of exposure data provides evidence of declining concentrations of certain organochlorine pesticides in some avian species (e.g., ospreys, Pandion haliaetus), and an apparent increase in the detection and possibly the incidence of avian die-offs related to cholinesterase-inhibiting pesticides. To identify spatial data gaps, 11,360 database records with specific sampling locations were combined with the boundaries of coastal watersheds, and National Wildlife Refuge and National Park units. Terrestrial vertebrate ecotoxicological data were lacking in 41.9% of 464 coastal watersheds in the continental United States. Recent (1990-2003) terrestrial vertebrate contaminant exposure or effects data were available for only about half of the National Wildlife Refuge and National Park units in the geographic area encompassed by the database. When these data gaps were overlaid on watersheds exhibiting serious water quality problems and/or high vulnerability to pollution, 72 coastal watersheds, and 76 National Wildlife Refuge and 59 National Park units in the continental United States were found to lack recent terrestrial vertebrate ecotoxicology data. Delineation of data gaps in watersheds of concern can help prioritize monitoring in areas with impaired water quality and emphasize the need for comprehensive monitoring to gain a more complete understanding of coastal ecosystem health.

Clinical analysis of non-accidental head injury in infants.

We present the clinical features, radiological findings and outcome of infants with non-accidental head injury presenting to our department between 2001 and 2003. There were 26 male and 13 female infants, aged between 7 days and 5 months. Presenting symptoms included seizures, vomiting, bulging fontanel, decreased level of consciousness, focal neurological signs, anemia and respiratory distress. We classified the patients into three groups: mild head injury (8 patients), moderate head injury (11 patients) and severe head injury (20 patients). Detailed history taking and thorough physical examination, did not reveal obvious injury or abuse (by the parents), other external visible injury or significant incidence of retinal bleeding. CT scan showed intracranial hemorrhage in all patients, most commonly including acute or acute on chronic subdural hematoma (SDH) and subarachnoid hemorrhage (SAH) in the parafalcine and tentorial regions and over the brain convexity, associated with focal or diffuse hypodensity of the parenchyma. Intracranial lesions were mostly bilateral (80%). These patients generally had a poor outcome; 31% died, 23% had a good outcome, and the remainder recovered with neurological impairment of varying types and degrees. After comprehensive assessment, we concluded that all the cases in our series were "non-accidental" head injuries. However, the absence of retinal bleeding, visible external injury and recognised abuse in our series differed from reports by other investigators. In our opinion these features are not absolute requirements in diagnosing "non-accidental" injury and detailed history taking, thorough clinical examination and radiological studies were the key indicators of the diagnosis.

Contaminant exposure and reproductive success of ospreys (Pandion haliaetus) nesting in Chesapeake Bay regions of concern.

The Chesapeake Bay osprey population has more than doubled in size since restrictions were placed on the production and use of DDT and other toxic organochlorine contaminants in the 1970s. Ospreys are now nesting in the most highly polluted portions of the Bay. In 2000 and 2001, contaminant exposure and reproduction were monitored in ospreys nesting in regions of concern, including Baltimore Harbor and the Patapsco River, the Anacostia and middle Potomac rivers, and the Elizabeth River, and a presumed reference site consisting of the South, West, and Rhode rivers. A "sample egg" from each study nest was collected for contaminant analysis, and the fate of eggs remaining in each nest (n = 14-16/site) was monitored at 7- to 10-day intervals from egg incubation through fledging of young. Ospreys fledged young in regions of concern (observed success: 0.88-1.53 fledglings/active nest), although productivity was marginal for sustaining local populations in Baltimore Harbor and the Patapsco River and in the Anacostia and middle Potomac rivers. Concentrations of p,p'-DDE and many other organochlorine pesticides or metabolites, total PCBs, some arylhydrocarbon receptor-active PCB congeners and polybrominated diphenyl ether congeners, and perfluorooctanesulfonate were often greater in sample eggs from regions of concern compared to the reference site. Nonetheless, logistic regression analyses did not provide evidence linking marginal productivity to p,p'-DDE, total PCBs, or arylhydrocarbon receptor-active PCB congener exposure in regions of concern. In view of the moderate concentrations of total PCBs in eggs from the reference site, concerns related to new and emerging toxicants, and the absence of ecotoxicological data for terrestrial vertebrates in many Bay tributaries, a more thorough spatial evaluation of contaminant exposure in ospreys throughout the Chesapeake may be warranted.

Eating disorders in children and adolescents: epidemiology, diagnosis and treatment.

Eating disorders such as anorexia nervosa (AN) and bulimia nervosa (BN) are increasingly prevalent among children and adolescents. Whereas AN has a peak age of onset in early to mid-adolescence, BN typically presents during or after late adolescence. There is a spectrum of eating disorders that can be categorised by the criteria in the fourth edition of the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders into AN, BN and 'eating disorder not otherwise specified (ED-NOS)'. The key clinical signs of AN are those of protein calorie malnutrition. In BN, signs of purging are also important. Despite marked physical changes, metabolic decompensation occurs late and when present is an indication for hospital admission. During refeeding, electrolyte disturbances, in particular hypophosphataemia, should be serially monitored. For females with AN, restoration of gonadotropins, oestradiol and resumption of menses is a cardinal indicator of nutritional recovery. Treatment should address the medical, nutritional and psychological needs of children and adolescents with eating disorders. No single professional can be proficient in all spheres. Children and adolescents with eating disorders are best managed by a 'team approach'. Treatment may occur in a variety of inpatient, daypatient or outpatient settings. The aims of medical treatment are to promote bodyweight gain and nutritional recovery. Psychiatric goals address the psychosocial precipitants, treat comorbid mood symptoms and assist the patient to develop alternative coping skills. The crude mortality of AN has decreased to around 6%. For children and adolescents, the morbidity from malnutrition is increased because of the biological changes that are interrupted.

Emergency contraception: pediatricians' knowledge, attitudes, and opinions.

UNLABELLED: Emergency contraception (EC) is the use of a method of contraception after unprotected intercourse to prevent unintended pregnancy. Although first described over 20 years ago, physician awareness of EC has been limited and many feel uncomfortable prescribing it. OBJECTIVE: To assess the knowledge, attitudes, and opinions of practicing pediatricians regarding the use of EC in adolescents. METHODS: An anonymous questionnaire was mailed to all 954 active members of New York Chapter 2, District II of the American Academy of Pediatrics. The questionnaire assessed basic knowledge, attitudes, and opinions regarding EC in adolescents. Data were analyzed by physician age, gender, year completed residency, and practice type. RESULTS: Two hundred thirty-three practicing pediatricians (24.4%) completed the survey. Of the respondents, 23.7% had been asked to prescribe EC to an adolescent and 49% of these cases involved a rape victim. Only 16.7% of pediatricians routinely counsel adolescent patients about the availability of EC, with female pediatricians more likely to do so. Most respondents (72.9%) were unable to identify any of the Food and Drug Administration-approved methods of EC. Only 27.9% correctly identified the timing for its initiation and only 31.6% of respondents felt comfortable prescribing EC. Inexperience with use was cited as the primary reason for not prescribing EC by 70% of respondents. Twelve percent cited moral or religious reasons and 17% were concerned about teratogenic effects. There were no differences in comfort level based on age, gender, or practice type. Twenty-two percent of respondents believed that providing EC encourages adolescent risk-taking behavior and 52.4% would restrict the number of times they would dispense EC to an individual patient. A minority of respondents (17%) believed that adolescents should have EC available at home to use if necessary and only 19.6% believed that EC should be available without a prescription. The vast majority (87.5%) were interested in learning more about EC. CONCLUSIONS: Despite the safety and efficacy of EC, the low rate of use is of concern. Pediatricians are being confronted with the decision to prescribe EC but do not feel comfortable prescribing it because of inadequate training in its use. Practicing pediatricians are aware of their lack of experience and are interested in improving their knowledge base.

Random transposon mutagenesis of Campylobacter jejuni.

Genetic studies of Campylobacter jejuni have been limited due to the lack of a transposon mutagenesis method. Here, we describe a novel technique for random transposon mutagenesis using a mariner-based transposon into C. jejuni strain 480. Insertions were random, as demonstrated by Southern blot analysis and insertional junction sequencing. We have demonstrated, for the first time, random in vivo transposon mutagenesis of C. jejuni.

Cellular blue naevus of the scalp with brain invasion.

A case of a 28 year old woman with an intracranial cellular blue naevus (CBN) which was believed to be the extension from a pigmented skin/scalp lesion is reported. There was no similar pigmented skin lesion noted on other parts of her body. Radical intervention, including wide excision of the affected skin of the scalp, removal of the underlying pigmented skull bone and wide excision of the pigmented dura, together with wide excision of the intracranial mass, were performed. The skin defect was covered by rotation flap and free skin graft. The dura was closed by grafting with fascia lata. The skull defect was left open and would be repaired later at a second planned surgery.

Inhibition of thrombin generation by the zymogen factor VII: implications for the treatment of hemophilia A by factor VIIa.

Factor VII circulates as a single chain inactive zymogen (10 nmol/L) and a trace ( approximately 10-100 pmol/L) circulates as the 2-chain form, factor VIIa. Factor VII and factor VIIa were studied in a coagulation model using plasma concentrations of purified coagulation factors with reactions initiated with relipidated tissue factor (TF). Factor VII (10 nmol/L) extended the lag phase of thrombin generation initiated by 100 pmol/L factor VIIa and low TF. With the coagulation inhibitors TFPI and AT-III present, factor VII both extended the lag phase of the reaction and depressed the rate of thrombin generation. The inhibition of factor Xa generation by factor VII is consistent with its competition with factor VIIa for TF. Thrombin generation with TF concentrations >100 pmol/L was not inhibited by factor VII. At low tissue factor concentrations (<25 pmol/L) thrombin generation becomes sensitive to the absence of factor VIII. In the absence of factor VIII, factor VII significantly inhibits TF-initiated thrombin generation by 100 pmol/L factor VIIa. In this hemophilia A model, approximately 2 nmol/L factor VIIa is needed to overcome the inhibition of physiologic (10 nmol/L) factor VII. At 10 nmol/L, factor VIIa provided a thrombin generation response in the hemophilia model (0% factor VIII, 10 nmol/L factor VII) equivalent to that observed with normal plasma, (100% factor VIII, 10 nmol/L factor VII, 100 pmol/L factor VIIa). These results suggest that the therapeutic efficacy of factor VIIa in the medical treatment of hemophiliacs with inhibitors is, in part, based on overcoming the factor VII inhibitory effect. (Blood. 2000;95:1330-1335)

Regulation of prothrombinase activity by protein S.

The independent effect of protein S as prothrombinase inhibitor has been proposed to depend on binding to both coagulation factors Va and factor Xa or on the binding to phospholipid thereby limiting the phospholipid available for prothrombinase activity. In this study we show that plasma concentrations of protein S (300 nM) equilibrated with the prothrombinase components (factor Va, factor Xa, phospholipid) cause a profound inhibition at low phospholipid concentrations (approximately 0.2 microM). This inhibition by protein S of prothrombinase activity is abrogated with increasing phospholipid concentrations. Modeling of the effect of protein S on prothrombinase based only on the reported affinity of protein S for phospholipids (Kd approximately 10(-8) M) in an equilibrium model (Clotspeed), predicted the experimentally obtained thrombin generation rates at low phospholipid in the presence of protein S based on the diminished available phospholipid binding sites for the prothrombinase components. Consistently, initial rates of prothrombinase activity are already maximally inhibited when protein S is preincubated with the phospholipid prior to the addition of factor Xa, factor Va and prothrombin. The results indicate that the order of addition of prothrombinase components and the availability of phospholipid may have a profound influence on observed effects of protein S on prothrombinase activity. All prothrombinase components (factor Xa, factor Va, phospholipid) become available during the course of the physiological thrombin generation. The effect of protein S was therefore studied on tissue factor-induced, platelet-dependent thrombin generation. Protein S delayed and inhibited the rate of thrombin generation of tissue factor-induced thrombin formation when surface is provided at physiologic concentrations using isolated platelets (2 x 10(8)/ml). In contrast, protein S hardly affected thrombin generation in this model when platelets were pre-activated with collagen. Furthermore, the observed effects of addition of protein C and thrombomodulin in the absence or presence of protein S on tissue factor-induced, platelet-dependent thrombin generation, indicate that protein S and protein C may cooperate in the regulation of prothrombinase activity through independent mechanisms.

A one year prospective census of workload and process at a community hospital casualty room.

A prospective census of patients attending the casualty room of Wicklow District Hospital (a general practitioner operated service) for one year was performed. A total of 1564 attendances were recorded, of which 904 (58%) were male and 953 (61%) were eligible for free medical care. Almost half, 735 (47%) attended outside daytime hours. Concerning type of presentation, 637 (41%) attended with acute trauma, 450 (29%) attended with acute medical and 477 (30%) attended with elective problems. Repeat visits accounted for 5% of the total. Concerning outcome of consultation, 409 (26%) were given a prescription, 307 (20%) had blood tests, 263 (17%) received dressings, 183 (12%) were referred to secondary care, 168 (11%) were followed up by their GP, 146 (9%) had minor surgery, and 86 (5%) had no intervention. This study indicates that the hospital is responsible for a considerable workload, with a significant out of hours component.