23 research outputs found

    Evidence-Based Annotation of the Malaria Parasite's Genome Using Comparative Expression Profiling

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    A fundamental problem in systems biology and whole genome sequence analysis is how to infer functions for the many uncharacterized proteins that are identified, whether they are conserved across organisms of different phyla or are phylum-specific. This problem is especially acute in pathogens, such as malaria parasites, where genetic and biochemical investigations are likely to be more difficult. Here we perform comparative expression analysis on Plasmodium parasite life cycle data derived from P. falciparum blood, sporozoite, zygote and ookinete stages, and P. yoelii mosquito oocyst and salivary gland sporozoites, blood and liver stages and show that type II fatty acid biosynthesis genes are upregulated in liver and insect stages relative to asexual blood stages. We also show that some universally uncharacterized genes with orthologs in Plasmodium species, Saccharomyces cerevisiae and humans show coordinated transcription patterns in large collections of human and yeast expression data and that the function of the uncharacterized genes can sometimes be predicted based on the expression patterns across these diverse organisms. We also use a comprehensive and unbiased literature mining method to predict which uncharacterized parasite-specific genes are likely to have roles in processes such as gliding motility, host-cell interactions, sporozoite stage, or rhoptry function. These analyses, together with protein-protein interaction data, provide probabilistic models that predict the function of 926 uncharacterized malaria genes and also suggest that malaria parasites may provide a simple model system for the study of some human processes. These data also provide a foundation for further studies of transcriptional regulation in malaria parasites

    Plasmodium Protease ROM1 Is Important for Proper Formation of the Parasitophorous Vacuole

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    Apicomplexans are obligate intracellular parasites that invade host cells by an active process leading to the formation of a non-fusogenic parasitophorous vacuole (PV) where the parasite replicates within the host cell. The rhomboid family of proteases cleaves substrates within their transmembrane domains and has been implicated in the invasion process. Although its exact function is unknown, Plasmodium ROM1 is hypothesized to play a role during invasion based on its microneme localization and its ability to cleave essential invasion adhesins. Using the rodent malaria model, Plasmodium yoelii, we carried out detailed quantitative analysis of pyrom1 deficient parasites during the Plasmodium lifecycle. Pyrom1(-) parasites are attenuated during erythrocytic and hepatic stages but progress normally through the mosquito vector with normal counts of oocyst and salivary gland sporozoites. Pyrom1 steady state mRNA levels are upregulated 20-fold in salivary gland sporozoites compared to blood stages. We show that pyrom1(-) sporozoites are capable of gliding motility and traversing host cells normally. Wildtype and pyrom1(-) sporozoites do not differ in the rate of entry into Hepa1–6 hepatocytes. Within the first twelve hours of hepatic development, however, only 50% pyrom1(-) parasites have developed into exoerythrocytic forms. Immunofluorescence microscopy using the PVM marker UIS4 and transmission electron microscopy reveal that the PV of a significant fraction of pyrom1(-) parasites are morphologically aberrant shortly after invasion. We propose a novel function for PyROM1 as a protease that promotes proper PV modification to allow parasite development and replication in a suitable environment within the mammalian host

    New York State cases of anaphylaxis in elderly patients from 2000 to 2010.

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    BACKGROUND: Limited information is available on the effect of anaphylaxis, a severe, potentially life-threatening allergic reaction, in the elderly population. OBJECTIVE: To elucidate the frequency of anaphylaxis and the demographic characteristics of elderly patients admitted to New York hospitals from 2000 to 2010. METHODS: A retrospective analysis of hospitalized patients aged 65 years and older in New York from 2000 to 2010 was conducted using the Statewide Planning and Research Cooperative System, a statewide administrative database. Cases were identified using anaphylaxis International Classification of Diseases, Ninth Revision (ICD-9) codes or an ICD-9-based diagnostic algorithm incorporating the National Institutes of Allergy and Infectious Disease diagnostic criteria. The Ο‡ RESULTS: A total of 3673 hospitalizations were analyzed. Anaphylaxis ICD-9 codes identified 1790 cases (48.7%), the algorithms identified 1701 cases (46.3.%), and 182 cases (5.0%) were identified by both. Hospitalization rates increased significantly during this period (P \u3c .001). Women comprised 61.5% and people of white race comprised 69.8% of the sample. Distribution by age differed by ascertainment method (ICD-9 vs algorithm) among the early-old group (65-74 years of age; 53.8% vs 41.8%) and among the late-old group (β‰₯85 years of age; 11.2% vs 19.3%). CONCLUSION: Hospitalization rates and anaphylaxis cases increased during the study period among the hospitalized elderly population of New York. Relying on anaphylaxis ICD-9 codes alone missed approximately half of possible cases. The identification and possibly the effect of anaphylaxis among the elderly population may differ, depending on age, race, payer, New York County, and disposition

    Considerations in the diagnosis of chronic granulomatous disease

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    Β© The Author(s) 2018. Chronic granulomatous disease (CGD) is a rare primary immunodeficiency that is caused by defects in the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase complex. The disease presents in most patients initially with infection, especially of the lymph nodes, lung, liver, bone, and skin. Patients with CGD are susceptible to a narrow spectrum of pathogens, and Staphylococcus aureus, Burkholderia cepacia complex, Serratia marcescens, Nocardia species, and Aspergillus species are the most common organisms implicated in North America. Granuloma formation, most frequently in the gastrointestinal and genitourinary systems, is a common complication of CGD and can be seen even before diagnosis. An increased incidence of autoimmune disease has also been described in patients with CGD and X-linked female carriers. In patients who present with signs and symptoms consistent with CGD, a flow cytometric dihydrorhodamine neutrophil respiratory burst assay is a quick and cost-effective way to evaluate NADPH oxidase function. The purpose of this review is to highlight considerations for and challenges in the diagnosis of CGD

    Noninfectious manifestations and complications of chronic granulomatous disease

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    Β© The Author(s) 2018. Chronic granulomatous disease (CGD), a primary immunodeficiency characterized by a deficient neutrophil oxidative burst and the inadequate killing of microbes, is well known to cause a significantly increased risk of invasive infection. However, infectious complications are not the sole manifestations of CGD; substantial additional morbidity is driven by noninfectious complications also. These complications can include, for example, a wide range of inflammatory diseases that affect the gastrointestinal tract, lung, skin, and genitourinary tract and overt autoimmune disease. These diseases can occur at any age and are especially problematic in adolescents and adults with CGD. Many of these noninfectious complications present a highly challenging therapeutic conundrum, wherein immunosuppression must be balanced against an already markedly increased risk of invasive fungal and bacterial infections. In this review, the myriad noninfectious complications of CGD are discussed, as are important gaps in our understanding of these processes, which warrant further investigation

    PROMIS-29 survey confirms major impact of fatigue on health-related quality of life in common variable immunodeficiency

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    Β© 2020, Springer Science+Business Media, LLC, part of Springer Nature. Health-related quality of life (HRQOL) is an emerging topic of interest in patients with immunodeficiency. Information about HRQOL in common variable immunodeficiency (CVID) is limited. The primary objective was to compare primary immunodeficiency disease (PIDD) patients with and without common variable immunodeficiency (CVID) on HRQOL domains using Patient-Reported Outcomes Measurement Information System (PROMIS-29) survey data from the United States Immunodeficiency Network (USIDNET) registry. The primary endpoint variables were scores on 7 HRQOL domains. The USIDNET registry was used to select patients with baseline PROMIS-29 data collected between 2015 and 2018. Descriptive statistics, Fisher’s exact test, and Student’s two-sample t test were used to compare patients with CVID versus patients with non-CVID on demographic and clinical characteristics. The single-sample t test was used to compare sample means to the normed population mean of 50. A general linear model approach to multiple regression with backward selection was used to remove factors that did not contribute significant information to the multivariable models, while controlling for multiple testing. Potential explanatory variables included group (CVID/non-CVID), sex, age, and BMI. Among 184 PIDD patients, 146 (79%) were diagnosed with CVID. Patients had a mean (SD) age of 53 (13.8), were predominantly female (83%), and were Caucasian (98%). PROMIS-29 results revealed a significant effect of group (CVID/non-CVID) on the anxiety, fatigue, and social participation domains, with fatigue being the most statistically significant. Fatigue, anxiety, and social participation may be key factors influencing HRQOL among patients with CVID. Future prospective longitudinal studies using PROMIS-29 will be needed to confirm these findings and to determine the mechanisms through which these factors develop in CVID, and how they can be improved
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