Cognitive Test Performance among Nondemented Elderly African Americans and Whites

We examined the neuropsychological test performance of a randomly selected community sample of English-speaking non-Hispanic African American and white elders in northern Manhattan. All participants were diagnosed as nondemented by a neurologist, whose assessment was made independent of neuropsychological test scores. African American elders obtained significantly lower scores on measures of verbal and nonverbal learning and memory, abstract reasoning, language, and visuospatial skill than whites. After using a stratified random sampling technique to match groups on years of education, many of the discrepancies became nonsignificant; however, significant ethnic group differences on measures of figure memory, verbal abstraction, category fluency, and visuospatial skill remained. Discrepancies in test performance of education-matched African Americans and whites could not be accounted for by occupational attainment or history of medical conditions such as hypertension and diabetes. These findings emphasize the importance of using culturally appropriate norms when evaluating ethnically diverse elderly for dementia

Oblique-incidence reflectometry: one relative profile measurement of diffuse reflectance yields two optical parameters

A new, simple and quick approach, oblique-incidence reflectometry, was used to measure the absorption and reduced scattering coefficients of a semi-infinite turbid medium. An obliquely incident light beam causes the center of the far diffuse reflectance to shift from the point of incidence, where the far diffuse reflectance refers to the diffuse reflectance that is several transport mean free paths away from the incident point. The amount of shift yields the diffusion constant by a simple formula, and the slope of the diffuse reflectance yields the attenuation coefficient. Only the relative profile of the diffuse reflectance is needed to deduce both optical parameters, which makes this method attractive in clinical settings because it does not require a stringent calibration for absolute quantity measurements. This method was tested theoretically by Monte Carlo simulations and experimentally by a reflectometer. Because this method can be used to measure optical properties of biological tissues quickly and requires only inexpensive equipment, it has potential clinical application to the diagnosis of disease or monitoring of treatments

Recent Weather Extremes and Impacts on Agricultural Production and Vector-Borne Disease Outbreak Patterns

We document significant worldwide weather anomalies that affected agriculture and vector-borne disease outbreaks during the 2010-2012 period. We utilized 2000-2012 vegetation index and land surface temperature data from NASA's satellite-based Moderate Resolution Imaging Spectroradiometer (MODIS) to map the magnitude and extent of these anomalies for diverse regions including the continental United States, Russia, East Africa, Southern Africa, and Australia. We demonstrate that shifts in temperature and/or precipitation have significant impacts on vegetation patterns with attendant consequences for agriculture and public health. Weather extremes resulted in excessive rainfall and flooding as well as severe drought, which caused,10 to 80% variation in major agricultural commodity production (including wheat, corn, cotton, sorghum) and created exceptional conditions for extensive mosquito-borne disease outbreaks of dengue, Rift Valley fever, Murray Valley encephalitis, and West Nile virus disease. Analysis of MODIS data provided a standardized method for quantifying the extreme weather anomalies observed during this period. Assessments of land surface conditions from satellite-based systems such as MODIS can be a valuable tool in national, regional, and global weather impact determinations

Climate Teleconnections and Recent Patterns of Human and Animal Disease Outbreaks

Interannual climate variability associated with the El Niño/Southern Oscillation (ENSO) phenomenon and regional climatic circulation mechanisms in the equatorial Indian Ocean result in significant rainfall and ecological anomaly patterns that are major drivers of spatial and temporal patterns of mosquito-borne disease outbreaks. Correlation and regression analyses of long time series rainfall, vegetation index, and temperature data show that large scale anomalies occur periodically that may influence mosquito vector populations and thus spatial and temporal patterns of Rift Valley fever and chikungunya outbreaks. Rift Valley fever outbreak events occurred after a period of ∼3–4 months of persistent and above-normal rainfall that enabled vector habitats to flourish. On the other hand, chikungunya outbreaks occurred during periods of high temperatures and severe drought over East Africa and the western Indian Ocean islands. This is consistent with highly populated environmental settings where domestic and peri-domestic stored water containers were the likely mosquito sources. However, in Southeast Asia, approximately 52% of chikungunya outbreaks occurred during cooler-than-normal temperatures and were significantly negatively correlated with drought. Besides climate variability, other factors not accounted for such as vertebrate host immunity may contribute to spatio-temporal patterns of outbreaks

Trajectories of Quality of Life after Hematopoietic Cell Transplantation: Secondary Analysis of BMT CTN 0902 Data

Quality of life is increasingly recognized as an important secondary endpoint of hematopoietic cell transplantation (HCT). The current study examined the extent to which attrition results in biased estimates of patient quality of life. The study also examined whether patients differ in terms of trajectories of quality of life in the first six months post-transplant. A secondary data analysis was conducted of 701 participants who enrolled in the Blood and Marrow Transplantation Clinical Trials Network (BMT CTN) 0902 trial. Participants completed the SF-36, a measure of quality of life, prior to transplant and 100 and 180 days post-transplant. Results indicated that attrition resulted in slightly biased overestimates of quality of life but the amount of overestimation remained stable over time. Patients could be grouped into three distinct classes based on physical quality of life: 1) low and stable; 2) average and declining, then stable; and 3) average and stable. Four classes of patients emerged for mental quality of life: 1) low and stable; 2) average, improving, then stable; 3) higher than average (by almost 1 SD) and stable; and 4) average and stable. Taken together, these data provide a more comprehensive understanding of quality of life that can be used to educate HCT recipients and their caregivers

The First Prediction of a Rift Valley Fever Outbreak

El Nino/Southern Oscillation (ENSO) related anomalies were analyzed using a combination of satellite measurements of elevated sea surface temperatures, and subsequent elevated rainfall and satellite derived normalized difference vegetation index data. A Rift Valley fever risk mapping model using these climate data predicted areas where outbreaks of Rift Valley fever in humans and animals were expected and occurred in the Horn of Africa from December 2006 to May 2007. The predictions were subsequently confirmed by entomological and epidemiological field investigations of virus activity in the areas identified as at risk. Accurate spatial and temporal predictions of disease activity, as it occurred first in southern Somalia and then through much of Kenya before affecting northern Tanzania, provided a 2 to 6 week period of warning for the Horn of Africa that facilitated disease outbreak response and mitigation activities. This is the first prospective prediction of a Rift Valley fever outbreak

Global Disease Outbreaks Associated with the 2015–2016 El Niño Event

Interannual climate variability patterns associated with the El Niño-Southern Oscillation phenomenon result in climate and environmental anomaly conditions in specific regions worldwide that directly favor outbreaks and/or amplification of variety of diseases of public health concern including chikungunya, hantavirus, Rift Valley fever, cholera, plague, and Zika. We analyzed patterns of some disease outbreaks during the strong 2015–2016 El Niño event in relation to climate anomalies derived from satellite measurements. Disease outbreaks in multiple El Niño-connected regions worldwide (including Southeast Asia, Tanzania, western US, and Brazil) followed shifts in rainfall, temperature, and vegetation in which both drought and flooding occurred in excess (14–81% precipitation departures from normal). These shifts favored ecological conditions appropriate for pathogens and their vectors to emerge and propagate clusters of diseases activity in these regions. Our analysis indicates that intensity of disease activity in some ENSO-teleconnected regions were approximately 2.5–28% higher during years with El Niño events than those without. Plague in Colorado and New Mexico as well as cholera in Tanzania were significantly associated with above normal rainfall (p \u3c 0.05); while dengue in Brazil and southeast Asia were significantly associated with above normal land surface temperature (p \u3c 0.05). Routine and ongoing global satellite monitoring of key climate variable anomalies calibrated to specific regions could identify regions at risk for emergence and propagation of disease vectors. Such information can provide sufficient lead-time for outbreak prevention and potentially reduce the burden and spread of ecologically coupled diseases

Perturbation of Cytochrome c Maturation Reveals Adaptability of the Respiratory Chain in Mycobacterium tuberculosis

ABSTRACT Mycobacterium tuberculosis depends on aerobic respiration for growth and utilizes an aa3-type cytochrome c oxidase for terminal electron transfer. Cytochrome c maturation in bacteria requires covalent attachment of heme to apocytochrome c, which occurs outside the cytoplasmic membrane. We demonstrate that in M. tuberculosis the thioredoxin-like protein Rv3673c, which we named CcsX, is required for heme insertion in cytochrome c. Inactivation of CcsX resulted in loss of c-type heme absorbance, impaired growth and virulence of M. tuberculosis, and induced cytochrome bd oxidase. This suggests that the bioenergetically less efficient bd oxidase can compensate for deficient cytochrome c oxidase activity, highlighting the flexibility of the M. tuberculosis respiratory chain. A spontaneous mutation in the active site of vitamin K epoxide reductase (VKOR) suppressed phenotypes of the CcsX mutant and abrogated the activity of the disulfide bond-dependent alkaline phosphatase, which shows that VKOR is the major disulfide bond catalyzing protein in the periplasm of M. tuberculosis. IMPORTANCE Mycobacterium tuberculosis requires oxygen for growth; however, the biogenesis of respiratory chain components in mycobacteria has not been explored. Here, we identified a periplasmic thioredoxin, CcsX, necessary for heme insertion into cytochrome c. We investigated the consequences of disrupting cytochrome c maturation (CCM) for growth and survival of M. tuberculosis in vitro and for its pathogenesis. Appearance of a second-site suppressor mutation in the periplasmic disulfide bond catalyzing protein VKOR indicates the strong selective pressure for a functional cytochrome c oxidase. The observation that M. tuberculosis is able to partially compensate for defective CCM by upregulation of the cytochrome bd oxidase exposes a functional role of this alternative terminal oxidase under normal aerobic conditions and during pathogenesis. This suggests that targeting both oxidases simultaneously might be required to effectively disrupt respiration in M. tuberculosis