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.

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.

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.

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.

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.

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.

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.

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.

Comparative neurovirulence and tissue tropism of wild-type and attenuated strains of Venezuelan equine encephalitis virus administered by aerosol in C3H/HeN and BALB/c mice

To assess the potential for aerosol administration of vaccines for Venezuelan equine encephalitis virus (VEE), we compared the neurovirulence and tissue tropism of the wild-type Trinidad donkey (TrD) strain to those of the attenuated TC83 and V3526 strains of VEE in mice. Six to 8-week-old female C3H/HeN and BALB/c mice were aerosol exposed to one of the three VEE strains. Three mice of each strain were euthanatized at different times and their tissues were processed and stained using hematoxylin and eosin, immunohistochemistry, and in situ hybridization. All three viral strains infected the brains of mice and induced encephalitis. TrD spread caudally from the olfactory bulbs to all regions of the brain, caused widespread necrotizing panencephalitis by day 5, and resulted in 100% mortality (geometric mean = 7 days) in both mouse strains. By comparison, TC83 relatively spared the caudal regions of the brain but still caused 100% mortality in the C3H/HeN mice (geometric mean = 12 days), yet it did not kill any BALB/c mice. V3526 infectivity of the brain was the most limited, mainly affecting the neocortex and diencephalon. This virus was not lethal in either mouse strain. The TrD strain also infected the olfactory neuroepithelium, local lymphoid tissues, teeth, and vomeronasal organs, whereas the affinity of TC83 and V3526 outside the brain was essentially limited to the olfactory neuroepithelium. Attenuated VEE strains administered to mice by aerosol have restricted tissue tropism as compared with wild-type virus; however, even attenuated strains can infect the brain and induce encephalitis.

Antibiotic treatment of experimental pneumonic plague in mice

A mouse model was developed to evaluate the efficacy of antibiotic treatment of pneumonic plague; streptomycin was compared to antibiotics with which there is little or no clinical experience. Infection was induced by inhalation of aerosolized Yersinia pestis organisms. Antibiotics were administered by intraperitoneal injection every 6 hours for 5 days, at doses that produced levels of drug in serum comparable to those observed in humans treated for other serious infections. These studies compared in vitro to in vivo activity and evaluated the efficacy of antibiotics started at different times after exposure. Early treatment (started 24 h after challenge, when 0 of 10 mice tested had positive blood cultures) with netilmicin, ciprofloxacin, ofloxacin, ceftriaxone, ceftazidime, aztreonam, ampicillin, and rifampin (but not cefazolin, cefotetan, or ceftizoxime) demonstrated efficacy comparable to streptomycin. Late treatment (started 42 h after exposure, when five of five mice tested had positive blood cultures) with netilmicin, ciprofloxacin, ofloxacin, and a high dose (20 mg/kg of body weight every 6 h) of gentamicin produced survival rates comparable to that with streptomycin, while all of the beta-lactam antibiotics (cefazolin, cefotetan, ceftriaxone, ceftazidime, aztreonam, and ampicillin) and rifampin were significantly inferior to streptomycin. In fact, all groups of mice treated late with beta-lactam antibiotics experienced accelerated mortality rates compared to normal-saline-treated control mice. These studies indicate that netilmicin, gentamicin, ciprofloxacin, and ofloxacin may be alternatives for the treatment of pneumonic plague in humans. However, the beta-lactam antibiotics are not recommended, based upon poor efficacy in this mouse model of pneumonic plague, particularly when pneumonic plague may be associated with bacteremia.

Cancer statistics by race and ethnicity

Key findings on cancer incidence and mortality are presented for five racial and ethnic groups in the United States--African Americans, American Indians, Asians and Pacific Islanders, Hispanics, and whites. Information on the prevalence of cancer risk factors and screening examinations among these racial and ethnic groups is also included.

Studies on the role of plasminogen activator in systemic infection by virulent Yersinia pestis strain C092

Plasminogen activator is an outer membrane protease of Yersinia pestis encoded by the pla gene on plasmid pPst. Pla of the KIM-10 strain of Y. pestis appears to be required for the virulence from a subcutaneous (sc) but not an intraperitoneal (ip) or intravenous (iv) route of infection in mice. However, other strains of Y. pestis are highly virulent by the sc route yet lack pPst and pla. In this study, the pPst- Pestoides F strain was lethal to mice inoculated sc, with an LD50 (3 cfu), equal to that of C092, a virulent pPst+ strain. To analyse further the role of Pla in invasive infection, isogenic derivatives of C092, including one harboring pla with a frameshift mutation and another cured of pPst, were made. Although the ip LD50 of pPst- C092 and of the pla mutant were nearly identical to that of the wild type, the subcutaneous LD50 of the cured and mutant strains were 4 to 6 logs greater than that of wild type. Thus, pPst appears to be required for development of a lethal infection by some strains after sc inoculation but not after direct ip inoculation. Pla-associated virulence did not appear to be mediated by interference with the phagocyte chemoattractant C5a, as shown by the lack of correlation of C5a production with susceptibility to Y. pestis in C5a+ and C5a- congenic mice. In a footpad model of the early host response to subcutaneous infection, pPst- C092 proliferated at the subcutaneous injection site to a similar extent as did the wild type parent strain, and elicited a similarly large, local inflammatory response. However, the wild type was present at higher concentrations at more distant sites such as the popliteal lymph node and spleen.

Bacterial filamentation of Yersinia pestis by beta-lactam antibiotics in experimentally infected mice

OBJECTIVE

To identify alternatives to streptomycin for treating pneumonic plague, we evaluated beta-lactam antibiotics to treat experimental pneumonic plague in mice.

METHODS

Mice were exposed to a lethal inhaled dose of Yersinia pestis and treated with beta-lactam antibiotics administered every 6 hours, starting 42 hours postexposure.

RESULTS

The mice died or were euthanized in extremis 3 days postexposure. We observed marked bacterial filamentation of Y pestis in the tissues of mice treated with ceftazidime (10/10 mice), aztreonam (9/10 mice), or ampicillin (1/10 mice), but not in the tissues of mice treated with cefotetan, cefazolin, ceftriaxone, or saline. There was no evidence of septation of the filamentous bacteria by light or electron microscopy. The filamentous bacteria were confirmed as Y pestis based on their reactivity with rabbit anti-Y pestis F1 serum.

CONCLUSIONS

Marked bacterial filamentation of Y pestis can be produced in vivo by certain beta-lactam antibiotics. This antibiotic-induced morphologic change is important because filamentous bacteria in clinical samples could possibly be confused with filamentous actinomycotic organisms.

Pathology of experimental Ebola virus infection in African green monkeys. Involvement of fibroblastic reticular cells

BACKGROUND

Ebola virus has been responsible for explosive lethal outbreaks of hemorrhagic fever in both humans and nonhuman primates. Previous studies showed a predilection of Ebola virus for cells of the mononuclear phagocyte system and endothelial cells.

OBJECTIVE

To examine the distribution of lesions and Ebola virus antigen in the tissues of six adult male African green monkeys (Cercopithecus aethiops) that died 6 to 7 days after intraperitoneal inoculation of Ebola-Zaire (Mayinga) virus.

METHODS

Tissues were examined histologically, immunohistochemically, and ultrastructurally.

RESULTS

A major novel finding of this study was that fibroblastic reticular cells were immunohistochemically and ultrastructurally identified as targets of Ebola virus infection.

CONCLUSIONS

The role of Ebola virus-infected fibroblastic reticular cells in the pathogenesis of Ebola hemorrhagic fever warrants further investigation. This is especially important because of recent observations indicating that fibroblastic reticular cells, along with the reticular fibers they produce, maximize the efficiency of the immune response.

Experimental infection of nonhuman primates with sandfly fever virus

Due to the lack of an animal model, previous studies of sandfly fever have relied upon human challenge trials. We examined the infectivity and potential pathogenicity of sandfly fever virus in cynomolgus monkeys (Macaca fascicularis). Three different preparations of sandfly fever virus. Sicilian strain, and a placebo were compared by different routes of administration. The most notable postchallenge clinical event was a decrease in lymphocytes in the intramuscularly challenged monkeys. Plaque-reduction neutralization responses peaked earlier in animals challenged intravenously as compared with those in animals challenged intramuscularly. There was no evidence for neurotropism or meningeal inflammation. Sandfly fever virus was infectious for cynomolgus monkeys, but produced no detectable clinical disease that might serve as a marker for animal modeling studies. On the other hand, the preclinical data provide supportive evidence for safe parenteral administration of a Sicilian strain of sandfly fever virus inoculum to humans as a challenge model for sandfly fever disease.

Lethal experimental infection of rhesus monkeys with Ebola-Zaire (Mayinga) virus by the oral and conjunctival route of exposure

OBJECTIVE

The source of infection or mode of transmission of Ebola virus to human index cases of Ebola fever has not been established. Field observations in outbreaks of Ebola fever indicate that secondary transmission of Ebola virus is linked to improper needle hygiene, direct contact with infected tissue or fluid samples, and close contact with infected patients. While it is presumed that the virus infects through either breaks in the skin or contact with mucous membranes, the only two routes of exposure that have been experimentally validated are parenteral inoculation and aerosol inhalation. Epidemiologic evidence suggests that aerosol exposure is not an important means of virus transmission in natural outbreaks of human Ebola fever; this study was designed to verify that Ebola virus could be effectively transmitted by oral or conjunctival exposure in nonhuman primates.

MATERIALS AND METHODS

Adult rhesus monkeys (Macaca mulatta) were exposed to Ebola-Zaire (Mayinga) virus orally (N=4), conjunctivally (N=4), or by intramuscular inoculation (N=1, virus-positive control).

RESULTS

Four of four monkeys exposed by the conjunctival route, three of four monkeys exposed by the oral route, and the intramuscularly inoculated positive control monkey (one of one) were successfully infected with Ebola-Zaire (Mayinga). Seven monkeys died of Ebola fever between days 7 and 8 postexposure. One monkey was given aggressive supportive therapy and a platelet transfusion; it lived until day 12 postexposure.

CONCLUSIONS

Findings in this study experimentally confirm that Ebola virus can be effectively transmitted via the oral or conjunctival route of exposure in nonhuman primates.

Pathology of experimental pneumonic plague produced by fraction 1-positive and fraction 1-negative Yersinia pestis in African green monkeys (Cercopithecus aethiops)

OBJECTIVE

The protein capsule of Yersinia pestis, known as Fraction 1 or F1, is a protective immunogen and is an assumed, but not proven, virulence factor. Our objectives were to determine if inhaled F1-negative and/or F1-positive strains of Y pestis were virulent in the African green monkey and, if so, to differentiate F1-negative from F1-positive monkeys. Because F1-negative strains have been isolated from natural sources and have caused experimental fatal disease, we felt that this information was crucial to the development of future vaccines and diagnostic tests.

MATERIALS AND METHODS

Adult African green monkeys were exposed by aerosol to F1-positive (CO92, n=15) or F1-negative (CO92-C12, n=6; Java-9, n=2) Y pestis strains.

RESULTS

All monkeys died 4 to 10 days postexposure and had lesions consistent with primary pneumonic plague. Antibodies to F1 antigen and other Y pestis antigens allowed us to differentiate F1-positive from F1-negative Y pestis strains in fixed tissues.

CONCLUSIONS

In this study, F1 antigen was not a required virulence factor. Therefore, there may be a need for vaccines and diagnostic assays that are not solely based on the F1 antigen.

Venezuelan equine encephalitis in BALB/c mice: kinetic analysis of central nervous system infection following aerosol or subcutaneous inoculation

OBJECTIVE

To investigate the routes of entry of Venezuelan equine encephalitis (VEE) virus into the brain, we infected BALB/c mice with a virulent strain (V3000) by aerosol or subcutaneous inoculation.

METHODS

Immunohistochemistry and in situ hybridization methods were used to detect VEE virus in tissues taken at daily intervals postinfection.

RESULTS

In both groups, virus in the brain first appeared in olfactory regions. Aerosol exposure caused early massive infection of olfactory epithelium, which developed into bilaterally symmetrical infection of the olfactory nerves, olfactory bulbs, and lateral olfactory tracts by day 2 postinfection. After subcutaneous inoculation, VEE in the brain also appeared first in olfactory regions, but was not detected until day 3 postinfection. By day 4 postinfection, VEE viral infection had spread throughout the brain in both groups. Vascular endothelium and the choroid plexus remained uninfected during the entire study.

CONCLUSIONS

Our findings suggest that VEE virus, whether given by aerosol or subcutaneously, first enters the brain through the olfactory tract.

Pathology of experimental inhalation anthrax in the rhesus monkey

BACKGROUND

The inhalation form of anthrax, although rare, is nearly always fatal because of the rapid progression of the disease with little host response until the terminal stages of the disease. The Gulf War heightened the concern that anthrax could be used as a biologic weapon. Past studies modeling pathologic changes in human inhalation anthrax have used the rhesus monkey.

EXPERIMENTAL DESIGN

We studied pathologic changes in the rhesus monkey model of inhalation anthrax. Gross examination as well as light and electron microscopy were used to define pathologic alterations. Immunolabeling techniques were used to identify the anthrax bacillus by light and electron microscopy.

RESULTS

Gross changes included hemorrhage in mesenteric (54%) and tracheobronchial (46%) lymph nodes, meninges (38%), lungs (31%), and small intestinal serosa (31%). Histopathologic changes included suppurative meningitis (77%); hemorrhages in the meninges (54%), neuropil (31%), and pulmonary alveoli (31%); and pneumonia (15%). Spleens and various lymph nodes from all monkeys had one or more of the following changes: hemorrhage, acute inflammation, extracellular bacilli, lymphocytic depletion, and histiocytosis. Spleens of two monkeys were devoid of extracellular bacilli, but degraded intrahistiocytic bacilli reacted with Ab to Bacillus anthracis cell wall polysaccharide.

CONCLUSIONS

In our study, compared with previous reports, meningitis and mesenteric lymph node hemorrhages were more common, whereas mediastinal and tracheobronchial lymph node hemorrhages were less common. Immunostaining highlighted intracellular bacilli that would have been otherwise missed by light microscopic examination.

Spontaneously generated non-Hodgkin's lymphoma in twenty-seven simian T-cell leukemia virus type 1 antibody-positive baboons (Papio species)

Simian T-cell leukemia virus type 1 (STLV-1), a type C retrovirus associated with leukemia/lymphoma in Old World monkeys, is closely related to human T-cell leukemia virus type 1, the etiologic agent of adult T-cell leukemia/lymphoma in humans. In a colony of 3200 baboons, the prevalence of antibodies to STLV-1 is more than 40%. Seropositivity is more frequent in female baboons than in males and increases with age. Of 27 STLV-1 antibody-positive baboons with non-Hodgkin's lymphoma, 20 were females and 7 were males, ranging in age from 3 to 21 years (mean, 13 years). Non-Hodgkin's lymphoma was not found in STLV-1 antibody-negative baboons. Clinical signs and laboratory findings were variable but generally included lethargy, low body weights, anemia, dyspnea, lymphadenopathy, hepatosplenomegaly, pneumonia, nodular skin lesions, and leukemia with or without multilobulated lymphocytes in peripheral blood. Radiography revealed pulmonary infiltrates consistent with pneumonia in 17 of the baboons. Serum chemical values were normal except for hypercalcemia in one baboon. Lymphocytosis was found in 18 of the baboons, with leukemia diagnosed in 11. At necropsy, variable enlargement of lymph nodes and other lymphopoietic tissue was usually found. Pale tan to white space-occupying foci typical of proliferative lymphoid tissue were often found in various organs, including lungs, spleens, livers, skin, and hearts. The lungs in 14 baboons had thickened pleuras, congestion,edema, and large tan to brown areas of consolidation.(ABSTRACT TRUNCATED AT 250 WORDS)

The Rate Constant for the Recombination of Trifluoromethyl Radicals

The rotating sector data reported by Ayscough for the recombination of CF3radicals have been analysed by means of a method which takes into account all first-order radical removal processes, including CF3 radical addition to CF3COCF3, the radical source. The rate constant obtained, (1.48 � 0.50)×1013 cm3 mol-1 s-l, is substantially lower than the value originally reported.

Impact of physical fitness on strategy development in decision-making tasks

Data from 30 female subjects indicated that a 17.3% increase in a physical fitness index improved by 12% to 68% the information processing and decision-making capabilities of the subjects. The changes in physical fitness did not affect the performance on a variety of other tasks.