Atmospheric Carbon and Transport - America (ACT-America) Data Sets: Description, Management, and Delivery.

The ACT-America project is a NASA Earth Venture Suborbital-2 mission designed to study the transport and fluxes of greenhouse gases. The open and freely available ACT-America data sets provide airborne in situ measurements of atmospheric carbon dioxide, methane, trace gases, aerosols, clouds, and meteorological properties, airborne remote sensing measurements of aerosol backscatter, atmospheric boundary layer height and columnar content of atmospheric carbon dioxide, tower-based measurements, and modeled atmospheric mole fractions and regional carbon fluxes of greenhouse gases over the Central and Eastern United States. We conducted 121 research flights during five campaigns in four seasons during 2016-2019 over three regions of the US (Mid-Atlantic, Midwest and South) using two NASA research aircraft (B-200 and C-130). We performed three flight patterns (fair weather, frontal crossings, and OCO-2 underflights) and collected more than 1,140 h of airborne measurements via level-leg flights in the atmospheric boundary layer, lower, and upper free troposphere and vertical profiles spanning these altitudes. We also merged various airborne in situ measurements onto a common standard sampling interval, which brings coherence to the data, creates geolocated data products, and makes it much easier for the users to perform holistic analysis of the ACT-America data products. Here, we report on detailed information of data sets collected, the workflow for data sets including storage and processing of the quality controlled and quality assured harmonized observations, and their archival and formatting for users. Finally, we provide some important information on the dissemination of data products including metadata and highlights of applications of ACT-America data sets.

Key considerations and challenges in the application of social-network research for environmental decision making.

Attempts to better understand the social context in which conservation and environmental decisions are made has led to increased interest in human social networks. To improve the use of social-network analysis in conservation, we reviewed recent studies in the literature in which such methods were applied. In our review, we looked for problems in research design and analysis that limit the utility of network analysis. Nineteen of 55 articles published from January 2016 to June 2019 exhibited at least 1 of the following problems: application of analytical methods inadequate or sensitive to incomplete network data; application of statistical approaches that ignore dependency in the network; or lack of connection between the theoretical base, research question, and choice of analytical techniques. By drawing attention to these specific areas of concern and highlighting research frontiers and challenges, including causality, network dynamics, and new approaches, we responded to calls for increasing the rigorous application of social science in conservation.

Consideraciones y Retos Importantes en la Aplicación de la Investigación por medio de Redes Sociales para la Toma de Decisiones Ambientales Resumen Los intentos por tener un mejor entendimiento del contexto social en el que se toman las decisiones ambientales y de conservación han derivado en un incremento en el interés por las redes sociales humanas. Para mejorar el uso del análisis de redes sociales en la conservación, buscamos en la literatura los estudios recientes que hayan aplicado dichos métodos y los sometimos a una revisión. En esta revisión, examinamos los problemas en el diseño de la investigación y del análisis que limitan la utilidad del análisis de redes. Diecinueve de los 55 artículos publicados entre enero 2016 y junio 2019 exhibieron al menos uno de los siguientes problemas: aplicación de métodos analíticos inadecuados o sensibles a la información incompleta sobre las redes; aplicación de estrategias estadísticas que ignoran la dependencia en la red; o falta de conexión entre la base teórica, la pregunta de investigación y la selección de técnica analítica. Al llamar la atención hacia estas áreas específicas de interés y resaltar las fronteras y retos de la investigación, incluyendo la causalidad, las dinámicas de redes y las estrategias nuevas, respondimos a la necesidad de incrementar la aplicación rigurosa de las ciencias sociales en la conservación.

A two-year toxicology study of bisphenol A (BPA) in Sprague-Dawley rats: CLARITY-BPA core study results.

We report the data from the guideline-compliant two-year toxicology study conducted as part of the Consortium Linking Academic and Regulatory Insights on Bisphenol A Toxicity (CLARITY-BPA). BPA (0, 2.5, 25, 250, 2,500, and 25,000 µg/kg body weight (bw)/day) was administered daily by gavage in 0.3% carboxymethylcellulose vehicle to NCTR Sprague-Dawley rats from gestation day 6 through the start of parturition and then directly to pups from the day after birth until postnatal day 21 (stop-dose arm) or continuously until termination at one or two years. The stop-dose arm was included to assess the potential for any BPA effects that were due to developmental exposure. No BPA-related effects were evident in the in-life and non-histopathology data. Neoplastic and nonneoplastic lesions diagnosed in both females and males were common age-associated lesions that were variable across control and BPA-treated groups. The lack of consistent responses within the continuous- and stop-dose arms within and across tissues brought into question the plausible relationship of most of these lesions to BPA treatment. There was a possible relationship between the increased incidences of lesions in the female reproductive tract and the male pituitary and exposure to the 25,000 µg BPA/kg bw/day dose level.

Evaluating the risk of pneumonia with inhaled corticosteroids in COPD: Retrospective database studies have their limitations SA.

An increased risk of non-fatal pneumonia has been documented in COPD patients treated with inhaled corticosteroids (ICS) in randomized clinical trials. Retrospective database analyses have been conducted to evaluate this signal in larger populations treated in the community. To understand how methodological choices may influence results in observational studies, we compared two recent Canadian studies which used health administrative databases from Quebec and Ontario and came to opposite conclusions on the risk of pneumonia in ICS treated COPD patients. Explanations for why the results of these studies diverged are explored. The Suissa analysis used RAMQ data from Quebec and showed an increased relative risk of serious pneumonia for current users of ICS compared to non users, RR = 1.69 (95% confidence interval, 1.63-1.75). The Gershon analysis used ODB data and showed no difference for pneumonia hospitalisation, RR = 1.01 (0.93-1.08). Reasons for differences in study findings include lack of validated definitions of COPD, poor selection of relevant exposure groups, channeling and confounding biases, and failure to perform on-treatment analyses for safety. CONCLUSION: Our study identifies methodological features that need consideration to increase robustness and minimize threats to internal validity of retrospective health administrative database studies.

Is Johnny wheezing? Parent-child agreement in the Childhood Asthma in America survey.

We compared responses of children and parents to determine their level of agreement in a national, population-based survey regarding asthma-related health of US children. A telephone-based survey was conducted in 2004 among a national probability sample of children with current asthma in the United States. To compare responses between parent-child pairs, a subset of 284 children aged 10-15 were interviewed in addition to the parents. This survey collected data on asthma symptom prevalence, physical activity limitations and impact of exercise on asthma, and asthma management including medication use. Paired responses were compared using the kappa (κ) statistic. Overall, parents of 10-15-yr-olds underestimated the burden of asthma experienced by their children, especially the effects on physical activity. More than half (58%) of children replied that exercise was a trigger for their asthma compared to only 35% of parents (κ 0.23). Children were more likely than parents to mention activity limitations, specifically avoiding physical exertion (63% vs. 49%-κ 0.004). Prevalence of symptoms was also underreported by parents relative to children, particularly breathing problems (41% vs. 67%-κ 0.16) and cough (45% vs. 64%-κ 0.14). Maintenance therapy use in the past 4 weeks was reported by 35% of children, whereas 44% of parents believed their children had used maintenance therapy (κ 0.47). Relative to children's self-report, parents underestimated avoidance tactics used by their children with asthma, including exercise and physical activity self-limitation to prevent the onset or worsening of asthma symptoms. Parents also underreported asthma symptoms of their children aged 10-15 years old and were discordant with their children regarding medication use. Increasing regular communication about asthma between child, parent, and physician is warranted to improve asthma control and overall health.

Academic stress and menstrual disorders among female undergraduates in Uyo, South Eastern Nigeria - the need for health education.

The aim of this study was to determine the association between academic stress and menstrual disorders among female undergraduates in Uyo, South Eastern Nigeria. Three hundred and ninety-three (393) female students of the University of Uyo, ages between 16 and 35 years were randomly selected from different departments in the University, and studied during the 2009/2010 academic session. Menstrual history and Student's Stress Assessment Questionnaire (SSAQ) were used for this assessment. They were distributed for participants to fill out. Prevalence of menstrual disorder among participants was 34.6%. A direct association between menstrual disorder and academic stress was observed. Commonest menstrual disorder was menorrhagia (37.5%). Others were: Pre-menstrual Syndrome (PMS 33.1%), Oligomenorrhea 19.9% and amenorrhea 5.9% (P<0.05). Those who experienced academic stress had about 2 times chances of having menstrual disorders (OR : 2.0, C.I = 1.224-2.837) at P<0.05. This study demonstrated a significant association between academic stress and menstrual disorder among females undergraduate in Uyo, South Eastern Nigeria.

Pelvic floor dysfunction: a scoping study exploring current service provision in the UK, interprofessional collaboration and future management priorities.

OBJECTIVE: Pelvic floor dysfunction (PFD) has a significant socioeconomic and healthcare cost. This study aimed to investigate current service provision for PFD in the UK, highlighting any gaps and areas for improvement to inform future service improvement. METHODS: A three-phase design comprised a scoping literature review, consultation survey with frontline practitioners from four key professional groups and an overarching synthesis. An interpretative analytical framework was informed by the concepts of interdisciplinary and interprofessional collaboration. RESULTS: Empirical evidence on PFD service provision is limited. No overarching strategic approach to PFD as a single clinical entity in the UK was identified. Two hundred and forty-three medical, nursing and physiotherapy practitioners from different clinical subspecialties participated in the survey. Access and availability to services, models of delivery and individual practice vary widely within and across the disciplines. Time restrictions, mixed professional attitudes, lack of standardisation and low investment priority were identified as major barriers to optimal service provision. Five overlapping areas for improvement are highlighted: access and availability, team working and collaboration, funding and investment, education, training and research, public and professional awareness. CONCLUSIONS: Current services are characterised by a fragmented approach with asynchronous delivery, limited investment and poor interprofessional integration. An improved service delivery model has the potential to improve outcomes through better interdisciplinary collaboration and efficient use of resources.

Relationship between lung function impairment and incidence or recurrence of cardiovascular events in a middle-aged cohort.

INTRODUCTION: Lung function impairment may be a risk factor for cardiovascular disease (CVD) events. OBJECTIVE: To determine the relationship between the severity of airflow obstruction based on modified Global Initiative on Obstructive Lung Disease (GOLD) criteria and the prevalence and incidence or recurrence of CVD in a cohort of US adults, aged 45-64 years, from 1987 to 2001. METHODS: We analysed data from 14 681 adults using logistic regression to determine the cross sectional association between lung function impairment and prevalent CVD at baseline and Cox regression to examine the prospective association of lung function impairment at baseline with CVD over 15 years of follow-up. Models were adjusted for age, sex, race, smoking, comorbid hypertension and diabetes, cholesterol levels and fibrinogen level. RESULTS: At baseline, the crude prevalence of CVD was higher among subjects with GOLD 2 (OR 2.9, 95% CI 2.4 to 3.6) and GOLD 3 or 4 chronic obstructive pulmonary disease (COPD) (OR 3.0, 95% CI 2.0 to 4.5), compared with normal subjects. These relative risks were greatly reduced after adjusting for covariates (OR 1.4, 95% CI 1.1 to 1.8 for GOLD 2 and OR 1.3, 95% CI 0.8 to 2.1 for GOLD 3 or 4). Similarly, the association between COPD and risk of incident or recurrent CVD was much stronger in the unadjusted models (hazard ratio (HR) 2.4, 95% CI 2.1 to 2.7 for GOLD 2 and 2.9, 95% CI 2.2 to 3.9 for GOLD 3 or 4) than in the adjusted ones (HR 1.2, 95% CI 1.03 to 1.4 for GOLD 2 and 1.5, 95% CI 1.1 to 2.0 for GOLD 3 or 4). CONCLUSION: We observed a crude association between lung function impairment and prevalent and incident or recurrent CVD that was greatly reduced after adjusting for covariates, including age, sex, race, smoking, comorbid hypertension and diabetes, cholesterol levels and fibrinogen level. These data suggest that this association may be, in part, mediated through established CVD risk factors included in our adjusted models.

Lung function decline and outcomes in an elderly population.

OBJECTIVE: To determine the risk factors for and outcomes associated with the rapid decline in lung function in a cohort of elderly US adults. METHODS: Data from 4923 adult participants aged 65 years and older at baseline in the Cardiovascular Health Study were analysed. Subjects were classified using a modification of the GOLD criteria for chronic obstructive pulmonary disease (COPD) and a "restricted" category (FEV1/FVC>or=70% and FVC<80% predicted) was added. Cox proportional hazard models were used to determine the risk of lung function decline over 4 years on subsequent mortality and COPD hospital admissions after adjusting for age, race, sex, smoking status, and other factors. RESULTS: Of the participants in the initial cohort, 3388 (68.8%) had spirometric tests at the year 4 visit. Participants with GOLD stages 3 or 4 COPD at baseline were less likely than normal subjects to have follow up spirometric tests (52.7% v 77.9%, p<0.01) and were more likely to be in the most rapidly declining quartile of FEV1 (28.2% v 21.3%, p<0.01) with an annual loss of FEV1 of at least 3.5%. Overall, being in the most rapidly declining quartile of FEV1 from baseline to year 4 was associated with an increased risk of admission to hospital for COPD (adjusted hazard ratio (HR) 1.6, 95% confidence interval (CI) 1.3 to 2.0) and all-cause death (adjusted HR 1.5, 95% CI 1.2 to 1.7) over an additional 7 years of follow up. CONCLUSION: More rapid decline in lung function is independently associated with a modest increased risk of hospital admissions and deaths from COPD in an elderly cohort of US participants.

Poor asthma control in children: evidence from epidemiological surveys and implications for clinical practice.

The objectives of this study is to compile current knowledge about asthma control in children in relation to goals proposed in international guidelines, to elucidate the factors associated with insufficient asthma control and to address the implications for clinical practice. Review of recent worldwide large population epidemiological surveys and clinical asthma studies of more than 20,000 children are the methods used in this study. The studies report high frequencies of sleep disturbances, emergency visits, school absence and limitations of physical activity due to asthma. Only a small percentage of children with asthma reach the goals of good asthma control set out by Global Initiative for Asthma (GINA). There is evidence of underuse of inhaled corticosteroids even in children with moderate or severe persistent asthma and over-reliance on short-acting beta(2)-agonist rescue medication. Both parents and physicians generally overestimate asthma control and have low expectations about the level of achievable control. Many children with asthma are not being managed in accordance with guideline recommendations, and asthma management practices vary widely between countries. Asthma control falls short of guideline recommendations in large proportions of children with asthma worldwide. Simple methods for assessing asthma control in clinical practice are needed. Treatment goals based on raised expectations should be established in partnership with the asthmatic child and the parents. Effective anti-inflammatory treatment should be used more frequently, and patients should be reviewed regularly.

Adjuvant biofeedback following anal sphincter repair: a randomized study.

AIMS: To evaluate the impact of adjuvant biofeedback following sphincter surgery. METHODS: Thirty-eight patients were randomized into sphincter repair or sphincter repair plus biofeedback groups. Outcome measures included a symptom questionnaire, patient's rating of satisfaction with continence function and improvement, change in continence score, quality of life and anorectal physiology. Endoanal ultrasonography was also performed pre- and post-operatively. RESULTS: Immediately following surgery, there was no statistically significant difference in any of the functional or physiological variables between the groups. Continence and patient satisfaction scores improved with a mean difference of -0.48 (95% CI: -3.30-2.33, P = 0.73) and 1.03 (95% CI: -1.40-3.46, P = 0.39), respectively. Only the difference in embarrassment scores reached statistical significance (mean) 0.56 (95% CI: 0.12-0.99, P = 0.014). Resting and squeeze pressures also improved. Thirteen of 14 in the biofeedback and 11 of 17 (control) reported symptomatic improvement. In the biofeedback group, although not statistically significant continence and satisfaction scores improved and were sustained over time. In the control group, continence and satisfaction scores changed little between 3 and 12 months (P = NS). Quality of life measures improved within the biofeedback group but there was no statistical difference between the groups. CONCLUSION: Following surgery continence function improves in all patients but adjuvant biofeedback therapy improves quality of life and maintains symptomatic improvement over time.

Systematic review: the epidemiology of ischaemic colitis.

BACKGROUND: Ischaemic colitis has been associated with co-morbid conditions, medications, vascular surgery and advanced age in case reports and case series. Few data exist on the baseline incidence in the general population or on the increased risk imposed by these risk factors. AIM: To systematically review the literature regarding the incidence, prevalence and risk factors for ischaemic colitis. METHODS: Searches of bibliographic databases were performed independently by two investigators. Studies were included if they used population-based samples, disease-specific population samples or case-control population-based samples of adults with ischaemic colitis, and reported the incidence, prevalence or risk factors for ischaemic colitis. Eligible articles were reviewed and data were abstracted in a duplicate, independent manner. RESULTS: Four studies were identified that reported the general population incidence and four that reported the disease-specific population incidence. The incidence of ischaemic colitis in general populations ranged from 4.5 to 44 cases per 100 000 person-years. The risk was increased two- to four-fold by either prevalent irritable bowel syndrome or chronic obstructive pulmonary disease. The risk was also increased in females and in subjects of 65 years and older. CONCLUSIONS: Ischaemic colitis is uncommon in the general population. The effect sizes of the most commonly reported risk factors have not been adequately quantified in population-based studies.

Component and whole-system respiration fluxes in northern deciduous forests.

We measured component and whole-system respiration fluxes in northern hardwood (Acer saccharum Marsh., Tilia americana L., Fraxinus pennsylvanica Marsh.) and aspen (Populus tremuloides Michx.) forest stands in Price County, northern Wisconsin from 1999 through 2002. Measurements of soil, leaf and stem respiration, stem biomass, leaf area and biomass, and vertical profiles of leaf area were combined with biometric measurements to create site-specific respiration models and to estimate component and whole-system respiration fluxes. Hourly estimates of component respiration were based on site measurements of air, soil and stem temperature, leaf mass, sapwood volume and species composition. We also measured whole-system respiration from an above-canopy eddy flux tower. Measured soil respiration rates varied significantly among sites, but not consistently among dominant species (P < 0.05 and P > 0.1). Annual soil respiration ranged from 8.09 to 11.94 Mg C ha(-1) year(-1). Soil respiration varied linearly with temperature (P < 0.05), but not with soil water content (P > 0.1). Stem respiration rates per unit volume and per unit area differed significantly among species (P < 0.05). Stem respiration per unit volume of sapwood was highest in F. pennsylvanica (up to 300 micro mol m(3) s(-1)) and lowest in T. americana (22 micro mol m(3) s(-1)) when measured at peak summer temperatures (27 to 29 degrees C). In northern hardwood stands, south-side stem temperatures were higher and more variable than north-side temperatures during leaf-off periods, but were not different statistically during leaf-on periods. Cumulative annual stem respiration varied by year and species (P < 0.05) and averaged 1.59 Mg C ha(-1) year(-1). Leaf respiration rates varied significantly among species (P < 0.05). Respiration rates per unit leaf mass measured at 30 degrees C were highest for P. tremuloides (38.8 nmol g(-1) s(-1)), lowest for Ulmus rubra Muhlenb. (13.1 nmol g(-1) s(-1)) and intermediate and similar (30.2 nmol g(-1) s(-1)) for T. americana, F. pennsylvanica and Q. rubra. During the growing season, component respiration estimates were dominated by soil respiration, followed by leaf and then stem respiration. Summed component respiration averaged 11.86 Mg C ha(-1) year(-1). We found strong covariance between whole-ecosystem and summed component respiration measurements, but absolute rates and annual sums differed greatly.

Spontaneous pancreatic islet amyloidosis in 40 baboons.

Spontaneous amyloidosis occurs in many nonhuman primate species but remains difficult to diagnose and treat. Nonhuman primates continue to offer promise as animal models in which to study amyloidosis in humans. Amyloidosis was not diagnosed clinically but was found histologically in four male and 36 female baboons. The baboons averaged 18 years of age at death (range, 7-28 years). Clinical signs, if present, were hyperglycemia and cachexia. Blood glucose values were elevated in 12 of 30 baboons with available clinical pathology data. Four baboons had been clinically diagnosed as diabetic and three were treated with insulin. Amyloid was found in the islets of Langerhans of the pancreas in 40 baboons; 35 baboons had amyloid only in the islets of Langerhans. Amyloid was found in nonislet tissue of baboons as follows: five, nonislet pancreas; four, intestine and adrenal; three, kidney; two, prostate and spleen; and one each, lymph node, liver, gall bladder, stomach, tongue, urinary bladder, and salivary gland. Sections of paraffin-embedded tissues were evaluated for amyloid with hematoxylin and eosin (HE) and congo red (CR) staining, and using immunohistochemistry for human islet amyloid polypeptide (IAPP), calcitonin gene-related peptide (CGRP), glucagon, pancreatic polypeptide (PP), somatostatin (SS), and porcine insulin. Islet amyloid was positive with HE in 40 baboons, with CR in 39 baboons, and with IAPP and CGRP in 35 baboons. IAPP and CGRP only stained islet amyloid. PP, SS, glucagon, and porcine insulin did not stain amyloid. Islet amyloidosis in the baboon appears to be difficult to diagnose clinically, age-related, and similar to islet amyloidosis in other species. The baboon may be a good model for the study of islet amyloidosis in humans.

Pathogenesis of experimental Ebola Zaire virus infection in BALB/c mice.

Guinea-pigs and non-human primates have traditionally been used as animal models for studying Ebola Zaire virus (EBO-Z) infections. The virus was also recently adapted to the stage of lethal virulence in BALB/c mice. This murine model is now in use for testing antiviral medications and vaccines. However, the pathological features of EBO-Z infection in mice have not yet been fully described. To identify sites of viral replication and characterize sequential morphological changes in BALB/c mice, adult female mice were infected with mouse-adapted EBO-Z and killed in groups each day for 5 days post-infection. Tissues were examined by light microscopy, immunohistochemistry, electron microscopy and in-situ hybridization. As in guinea-pigs and non-human primates, cells of the mononuclear phagocytic system were the earliest targets of infection. Viral replication was observed by day 2 in macrophages in lymph nodes and spleen. By the time of onset of illness and weight loss (day 3), the infection had spread to hepatocytes and adrenal cortical cells, and to macrophages and fibroblast-like cells in many organs. Severe lymphocytolysis was observed in the spleen, lymph nodes and thymus. There was minimal infection of endothelial cells. All of these changes resembled those observed in EBO-Z-infected guinea-pigs and non-human primates. In contrast to the other animal models, however, there was little fibrin deposition in the late stage of disease. The availability of immunodeficient, "gene-knockout" and transgenic mice will make the mouse model particularly useful for studying the early steps of Ebola pathogenesis.

The role of Mg2+ as an impurity in calcite growth.

Magnesium is a key determinant in CaCO3 mineralization; however, macroscopic observations have failed to provide a clear physical understanding of how magnesium modifies carbonate growth. Atomic force microscopy was used to resolve the mechanism of calcite inhibition by magnesium through molecular-scale determination of the thermodynamic and kinetic controls of magnesium on calcite formation. Comparison of directly measured step velocities to standard impurity models demonstrated that enhanced mineral solubility through magnesium incorporation inhibited calcite growth. Terrace width measurements on calcite growth spirals were consistent with a decrease in effective supersaturation due to magnesium incorporation. Ca(1-x)Mg(x)CO3 solubilities determined from microscopic observations of step dynamics can thus be linked to macroscopic measurements.

Specialized dementia programs in residential care settings.

The authors conducted a telephone survey in 7 states to determine the prevalence of residential care specialized dementia programs (RC-SDPs) and to identify a sample of homes (n = 56) for more detailed study. The 56 homes were site visited, and data were gathered on facility administration, therapeutic environment, and characteristics of 259 randomly selected residents. Comparison data from 138 nursing home Special Care Units (NH-SCUs) and 1,340 of their residents were obtained from 4 studies conducted in the same 7 states. RC-SDPs were smaller, provided a more homelike environment, and had a higher proportion of residents paying privately, compared with NH-SCUs. Mean levels of cognitive and physical impairment among residents were higher in NH-SCUs; prevalences of psychotropic medication use and problem behaviors were similar. Among RC facilities, small homes were more homelike, provided fewer structured activities, and charged less than larger facilities. RC-SDPs include 5 types: small, independently operated homes; multiple small homes with joint administration; larger, all-dementia facilities; SDPs operated within larger, exclusively RC facilities; and RC-SDPs in multilevel facilities.

American Cancer Society guidelines for the early detection of cancer.

This issue of CA inaugurates a yearly report on American Cancer Society guidelines for early detection of cancer in asymptomatic individuals. The current recommendations, which reflect almost 20 years of updates, cover screening recommendations for breast, colorectal, prostate, and cervical cancers, as well as for other cancers, depending on patient age, history, environmental and/or occupational exposures, etc. A key concept for both the general public and health providers is the distinction between public health recommendations regarding screening and decisions about early detection tests that might be undertaken on an individual basis. Although it is likely that current screening protocols will be supplanted by newer technologies, such as genetic and molecular markers of risk and disease, greater utilization of the technologies at hand will improve efforts toward establishing an organized and systematic approach to early cancer detection.

Isolation and chemical analysis of a lipopolysaccharide from the outer membrane of the oral anaerobic spirochete Treponema pectinovorum.

Isolation of a putative lipopolysaccharide from the surface of the oral treponeme, Treponema pectinovorum, revealed it to contain larger amounts of 3-deoxy-D-manno-octulosonic acid compared with other oral Treponema species. This molecule was isolated from the outer membrane of T. pectinovorum and had chemical characteristics of a putative lipopolysaccharide. The yield of lipopolysaccharide was between 0.6% and to 1.1% of the bacterial dry weight. The purified molecule was resistant to the action of proteinases and consisted of both sugars and lipids. 3-Deoxy-D-manno-octulosonic acid and hexoses accounted for 6.1-8.7% and 17.6-20.2%, respectively of the dry weight. Carbohydrate compositional analysis revealed the presence of glucose, galactose, 2-acetamido-2-deoxy-glucose, rhamnose and 6-deoxy-talose in the molar ratio of 1.00:0.96:0.19:0.88:0.98, respectively. No heptose was detected. The fatty acid analysis determined the presence of straight chain, C13:00, C14:00, C15:00 and C17:00 acids, as well as branched chain, C13:00, C14:00 and two species of C15:00, acids. Electrophoretic analysis indicated that the lipopolysaccharide was present as two major species.

Pathogenesis of experimental Ebola virus infection in guinea pigs.

The subtype Zaire of Ebola (EBO) virus (Mayinga strain) was adapted to produce lethal infections in guinea pigs. In many ways, the disease was similar to EBO infections in nonhuman primates and humans. The guinea pig model was used to investigate the pathologic events in EBO infection that lead to death. Analytical methods included immunohistochemistry, in situ hybridization, and electron microscopy. Cells of the mononuclear phagocyte system, primarily macrophages, were identified as the early and sustained targets of EBO virus. During later stages of infection, interstitial fibroblasts in various tissues were infected, and there was evidence of endothelial cell infection and fibrin deposition. The distribution of lesions, hematologic profiles, and increases in serum biochemical enzymes associated with EBO virus infection in guinea pigs was similar to reported findings in experimentally infected nonhuman primates and naturally infected humans.