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1

HIV-associated Opportunistic Pneumonias  

PubMed Central

Among the HIV-associated pulmonary complications, opportunistic pneumonias are major causes of morbidity and mortality. The spectrum of HIV-associated opportunistic pneumonias is broad and includes bacterial, mycobacterial, fungal, viral, and parasitic pneumonias. Bacterial pneumonia is the most frequent opportunistic pneumonia in the United States and Western Europe while tuberculosis (TB) is the dominant pathogen in sub-Saharan Africa. With the use of combination antiretroviral therapy and prophylaxis, the incidence of Pneumocystis pneumonia (PCP) has declined. Nevertheless, PCP continues to occur in persons who are unaware of their HIV infection, those who fail to access medical care, and those who fail to adhere to antiretroviral therapy or prophylaxis. Although pneumonias due to Cryptococcus neoformans, Histoplasma capsulatum, Coccidioides immitis, cytomegalovirus (CMV), and Toxoplasma gondii are less frequent, their presence in the lung is often indicative of disseminated disease and is associated with significant mortality. PMID:19645867

Huang, Laurence; Crothers, Kristina A.

2009-01-01

2

Systems analysis of human brain gene expression: mechanisms for HIV-associated neurocognitive impairment and common pathways with Alzheimer's disease  

PubMed Central

Background Human Immunodeficiency Virus-1 (HIV) infection frequently results in neurocognitive impairment. While the cause remains unclear, recent gene expression studies have identified genes whose transcription is dysregulated in individuals with HIV-association neurocognitive disorder (HAND). However, the methods for interpretation of such data have lagged behind the technical advances allowing the decoding genetic material. Here, we employ systems biology methods novel to the field of NeuroAIDS to further interrogate extant transcriptome data derived from brains of HIV?+?patients in order to further elucidate the neuropathogenesis of HAND. Additionally, we compare these data to those derived from brains of individuals with Alzheimer’s disease (AD) in order to identify common pathways of neuropathogenesis. Methods In Study 1, using data from three brain regions in 6 HIV-seronegative and 15 HIV?+?cases, we first employed weighted gene co-expression network analysis (WGCNA) to further explore transcriptome networks specific to HAND with HIV-encephalitis (HIVE) and HAND without HIVE. We then used a symptomatic approach, employing standard expression analysis and WGCNA to identify networks associated with neurocognitive impairment (NCI), regardless of HIVE or HAND diagnosis. Finally, we examined the association between the CNS penetration effectiveness (CPE) of antiretroviral regimens and brain transcriptome. In Study 2, we identified common gene networks associated with NCI in both HIV and AD by correlating gene expression with pre-mortem neurocognitive functioning. Results Study 1: WGCNA largely corroborated findings from standard differential gene expression analyses, but also identified possible meta-networks composed of multiple gene ontology categories and oligodendrocyte dysfunction. Differential expression analysis identified hub genes highly correlated with NCI, including genes implicated in gliosis, inflammation, and dopaminergic tone. Enrichment analysis identified gene ontology categories that varied across the three brain regions, the most notable being downregulation of genes involved in mitochondrial functioning. Finally, WGCNA identified dysregulated networks associated with NCI, including oligodendrocyte and mitochondrial functioning. Study 2: Common gene networks dysregulated in relation to NCI in AD and HIV included mitochondrial genes, whereas upregulation of various cancer-related genes was found. Conclusions While under-powered, this study identified possible biologically-relevant networks correlated with NCI in HIV, and common networks shared with AD, opening new avenues for inquiry in the investigation of HAND neuropathogenesis. These results suggest that further interrogation of existing transcriptome data using systems biology methods can yield important information. PMID:23406646

2013-01-01

3

cerebrospinal fluid of patients with HIV-associated neurological diseases  

Microsoft Academic Search

Matrix metalloproteinases (MMPs) have been identified as mediators of brain injury in HIV-associated neurological diseases. The activity of the 72 kDa gelatinase A (MMP-2) and 92 kDa gelatinase B (MMP-9) was detected by zymography in the cerebrospinal fluid (CSF) of 138 HIV-infected patients (40 with AIDS dementia, 83 with brain opportunistic infections and 15 neurologically asymptomatic), 26 HIV-seronegative individuals with

Grazia M Liuzzi; Claudio M Mastroianni; Maria P Santacroce; Margherita Fanelli; Claudia D'Agostino; Vincenzo Vullo; Paolo Riccio

4

Treatment guidelines for HIV-associated wasting.  

PubMed

Patients with acquired immunodeficiency syndrome (AIDS) often suffer from weight loss manifested by a loss of body cell mass (BCM). The causes of human immunodeficiency virus (HIV)-associated wasting may include anorexia, malabsorption, and a variety of altered metabolic states. Malabsorption and diarrhea may result from gastrointestinal tract opportunistic infections or from direct effects of HIV on the gastrointestinal tract. Infection with HIV may produce metabolic derangements that alter nutrient utilization, resulting in loss of BCM. Nutritional assessment of the patient with AIDS should include an evaluation of BCM and physical and psychosocial functioning. Antiretroviral therapy and eradication of opportunistic infections do not always reverse wasting. Treatment should include nutritional counseling. Total parenteral nutrition is sometimes of benefit, particularly in patients with damaged gastrointestinal tracts. Dronabinol and megestrol acetate may promote weight gain; however, dronabinol may have adverse effects, and most of the gain with megestrol acetate is in fat rather than BCM. If gonadal dysfunction is present, testosterone replacement therapy should be included in the treatment plan. Some studies suggest that oral anabolic steroids may improve muscle strength and body composition. In randomized, placebo-controlled trials, mammalian-derived human growth hormone (rhGH[m]) has produced sustained weight and BCM gains in AIDS patients. If a patient continues to lose BCM after the above factors have been addressed and corrected, a 12-week course of rhGH[m] is indicated. Halting the progression of HIV-associated wasting may improve survival, enhance physical and social functioning, and enrich quality of life. PMID:10761494

Nemechek, P M; Polsky, B; Gottlieb, M S

2000-04-01

5

HIV Associated Sensory Neuropathy  

PubMed Central

Background: In the era of highly active antiretroviral therapy, sensory neuropathies have increased in prevalence. We have documented the frequency and profile of the two most common forms of sensory neuropathies associated with Human Immunodeficiency Virus (HIV) infection and looked into clinicoelectrophysiological correlates to differentiate the two entities. Methods: The study population comprised of all consecutive patients detected to be HIV positive and attending the Neurology outpatient department (from March 2011 to March 2012) who were aged ? 18 years and were able to give informed consent. The data were collected from the patient records (including CD4 counts and treatment details) and questionnaire based interview with each patient. All patients underwent detailed clinical examination and nerve conduction studies (NCSs). Results: Among the total study population of 50 patients, there were 31 men and 19 women. Thirty two patients were in age range of 21 - 40 years and rest were above 40 years. 25 were on antiretroviral therapy (18 on regimen containing zidovudine; seven on regimen containing stavudine). The mean duration of antiretroviral therapy was 16.6±8.4 months. Low CD4 counts (<200) were noted in 24 patients (13 of these were on antiretroviral therapy). Clinically, the patients were classified as asymptomatic (n=34) and symptomatic (n=16). Among the symptomatic patients, nine were on antiretroviral therapy since less than one year (seven of these were on regimen containing stavudine). Ten patients aged more than 40-years had symptomatic neuropathy. No significant correlation was found between low CD4 counts and symptomatic neuropathy (p=0.21). Impaired vibration (100%) and absent ankle jerks (75%) were commoner than reduced pin sensitivity (46.6%). Twenty two patients had abnormal NCS results (18 of these were on antiretroviral therapy). Axonal distal symmetrical sensory neuropathy was the commonest pattern noted in 14 patients who were receiving antiretroviral therapy. Subclinical involvement as evidenced by abnormal NCSs was noted in 5 asymptomatic patients who were all on antiretroviral therapy. Conclusion: Symptomatic neuropathy was seen predominantly in HIV patients who were on antiretroviral therapy. All patients receiving stavudine containing regimen had severe symptomatic neuropathy within 1 year. There was an increase in the likelihood of symptomatic neuropathy among patients aged > 40 years. Subclinical neuropathy was common in those on antiretroviral therapy. Axonal neuropathy was the commonest pattern noted in patients who were receiving antiretroviral therapy and demyelinating neuropathy in patients not on antiretroviral therapy. Surprisingly no significant correlation was found between low CD4 counts and symptomatic neuropathy. PMID:25177587

S, Praveen-kumar; B, Nataraju; BS, Nagaraja

2014-01-01

6

HIV-associated intramammary lymphadenopathy.  

PubMed

The differential diagnosis of a breast mass in an HIV-infected patient is broad. We report a case of HIV-associated intramammary lymphadenopathy that manifested itself as a painful solitary breast mass best demonstrated by ultrasound imaging. Fine-needle aspiration (FNA), ultrasound-guided core needle biopsy, and subsequent excisional biopsy demonstrated an intramammary lymph node with reactive changes typical of acute HIV-associated lymphadenopathy. Intramammary lymphadenopathy, an otherwise under-reported entity, should be included in the differential diagnosis of a breast mass in an HIV-positive patient. FNA sampling alone can be adequate in such low suspicion breast lesions that appear benign on clinical and imaging evaluations, provided that sufficient cellular material is procured for ancillary studies to exclude infection and malignancy. PMID:17319863

Konstantinopoulos, Panagiotis A; Dezube, Bruce J; March, David; Pantanowitz, Liron

2007-01-01

7

Biomarkers of HIV-associated Cancer  

PubMed Central

Cancer biomarkers have provided great opportunities for improving the management of cancer patients by enhancing the efficiency of early detection, diagnosis, and efficacy of treatment. Every cell type has a unique molecular signature, referred to as biomarkers, which are identifiable characteristics such as levels or activities of a myriad of genes, proteins, or other molecular features. Biomarkers can facilitate the molecular definition of cancer, provide information about the course of cancer, and predict response to chemotherapy. They offer the hope of early detection as well as tracking disease progression and recurrence. Current progress in the characterization of molecular genetics of HIV-associated cancers may form the basis for improved patient stratification and future targeted or individualized therapies. Biomarker use for cancer staging and personalization of therapy at the time of diagnosis could improve patient care. This review focuses on the relevance of biomarkers in the most common HIV-associated malignancies, namely, Kaposi sarcoma, non-Hodgkin’s lymphoma, and invasive cervical cancer. PMID:25057241

Flepisi, Brian Thabile; Bouic, Patrick; Sissolak, Gerhard; Rosenkranz, Bernd

2014-01-01

8

HIV-Associated Venous Thromboembolism  

PubMed Central

HIV infection has been recognized as a prothrombotic condition and this association has now been proven by a large number of studies with a reported VTE frequency among HIV-infected patients ranging from 0.19% to 7,63 %/year. HIV infection is associated with a two to tenfold increased risk of venous thrombosis in comparison with a general population of the same age. Some risk factors demonstrated a strongest association with VTE such as, low CD4+ cell count especially in the presence of clinical AIDS, protein S deficiency, and protein C deficiency. Whereas other risk factors are still controversial like protease inhibitor therapy, presence of active opportunistic infections and presence of antiphospholipid antibodies, including anticardiolipin antibodies and lupus anticoagulant. Physicians caring for HIV positive patients should be able to recognize and treat not only the well-known opportunistic infections and malignancies associated with this chronic disease, but also be alert to the less well-known complications such as thromboses. Pulmonary embolism should be included in the differential diagnosis when patients with HIV/AIDS have unexplained dyspnea or hypoxemia. In younger individuals with VTE, especially men, without other identifiable risk factors for VTE, HIV should be considered. Because interactions between warfarin and antiretrovirals is possible, health care providers should also be alert to the potential of dangerously high or low INRs when they are giving anticoagulants to patients with HIV infection who are undergoing antiretroviral therapy. PMID:21869916

Bibas, Michele; Biava, Gianluigi; Antinori., Andrea

2011-01-01

9

HIV-associated lipodystrophy: Description, pathogenesis, and molecular pathways  

Microsoft Academic Search

HIV-infected individuals taking antiretroviral medications may experience changes in body shape and metabolism, commonly known\\u000a as HIV-associated lipodystrophy (HIVLD). In vitro and in vivo research have revealed numerous effects of both protease inhibitors\\u000a and nucleoside reverse transcriptase inhibitors on the function of various organs— most importantly adipose tissue, liver,\\u000a and muscle. The metabolic abnormalities could result in an increased risk

Patrick W. G. Mallon; Andrew Carr; David A. Cooper

2002-01-01

10

Tryptophan, Neurodegeneration and HIV-Associated Neurocognitive Disorder  

PubMed Central

This review presents an up-to-date assessment of the role of the tryptophan metabolic and catabolic pathways in neurodegenerative disease and HIV-associated neurocognitive disorder. The kynurenine pathway and the effects of each of its enzymes and products are reviewed. The differential expression of the kynurenine pathway in cells within the brain, including inflammatory cells, is explored given the increasing recognition of the importance of inflammation in neurodegenerative disease. An overview of common mechanisms of neurodegeneration is presented before a review and discussion of the evidence for a pathogenetic role of the kynurenine pathway in Alzheimer’s disease, HIV-associated neurocognitive disorder, Huntington’s disease, motor neurone disease, and Parkinson’s disease. PMID:22084594

Davies, Nicholas W.S.; Guillemin, Gilles; Brew, Bruce J.

2010-01-01

11

Drugs of Abuse, Dopamine, and HIV-Associated Neurocognitive Disorders\\/HIV-Associated Dementia  

Microsoft Academic Search

Although the incidence of HIV-associated dementia (HAD) has declined, HIV-associated neurocognitive disorders (HAND) remain\\u000a a significant health problem despite use of highly active antiretroviral therapy. In addition, the incidence and\\/or severity\\u000a of HAND\\/HAD are increased with concomitant use of drugs of abuse, such as cocaine, marijuana, and methamphetamine. Furthermore,\\u000a exposure to most drugs of abuse increases brain levels of dopamine,

Vishnudutt Purohit; Rao Rapaka; David Shurtleff

2011-01-01

12

Treatment of HIV-Associated Nephropathies  

Microsoft Academic Search

In patients with HIV, the use of highly active antiretroviral therapy has improved life expectancy. At the same time, this increase in life expectancy has been associated with a higher frequency of chronic kidney disease due to factors other than HIV infection. Besides HIV-associated nephropathy, a number of different types of immune complex and non-immune complex-mediated processes have been identified

Usama Elewa; Ana Maria Sandri; Stacey A. Rizza; Fernando C. Fervenza

2011-01-01

13

HIV-associated renal and genitourinary comorbidities in Africa.  

PubMed

With the recent massive scale-up of access to antiretroviral therapy (ART) in resource-limited countries, HIV has become a chronic disease with new challenges. There is mounting evidence of an increased burden of renal and genitourinary diseases among HIV-infected persons caused by direct HIV viral effects and/or indirectly through the development of opportunistic infections, ART medication-related toxicities, and other noncommunicable diseases (NCDs). We review the epidemiology of HIV-associated renal and urogenital diseases, including interactions with kidney-related NCDs such as hypertension, diabetes mellitus, and cardiovascular disease. We also examine the current evidence regarding the impact of HIV infection on the development of urogenital diseases. Highly advisable in sub-Saharan Africa are the establishment of renal disease registries, reviews of existing clinical practice including cost-effectiveness studies, and the adoption and use of HIV-related NCD management, with training for different cadres of health providers. Epidemiological research priorities include prospective studies to evaluate the true prevalence and spectrum of HIV-related renal disease and their progression. Simple diagnostics tools should be evaluated, including urinary dipsticks and point-of-care urea and creatinine tests to screen for kidney injury in primary care settings. Study of urological manifestations of HIV can help determine the extent of disease and outcomes. As patients live longer on ART, the burden of renal and genitourological complications of HIV and of ART can be expected to increase with a commensurate urgency in both discovery and evidence-based improvements in clinical management. PMID:25117962

Kalyesubula, Robert; Wearne, Nicola; Semitala, Fred C; Bowa, Kasonde

2014-09-01

14

Cytokine expression patterns distinguish HIV associated skin diseases.  

PubMed

AIDS is known to cause a shift of cytokines in the periphery. However, predominant cytokines in skin of patients with HIV-associated skin diseases have not been clearly defined. We hypothesized that there are distinct cytokine profiles that distinguish among the different clinical manifestations of AIDS-related skin diseases. To test this hypothesis, lesional and non-lesional skin was biopsied from 53 HIV+ patients with Kaposi's sarcoma (KS), psoriasis, and pruritus due to eosinophilic folliculitis, and from HIV negative controls with psoriasis or KS prior to therapy. Immunohistochemistry was performed with antibodies to tumor necrosis factor (TNF)-alpha, interleukin (IL)-10, interferon (IFN)-gamma, and interferon-inducible protein (IP)-10. HIV positive individuals included 10 with psoriasis, 14 with pruritus, and 15 with Kaposi's sarcoma. HIV negative controls included 12 with psoriasis and two with KS. Semi-quantitative analysis of cytokine staining was confirmed by optical density using a digital imaging system on four representative skin sections from each disease. Optical density analyses were conducted using ANOVA and t-tests. We found that epidermis overlying HIV+ Kaposi's sarcoma was hyperproliferative and was highest in IP-10, IFN-gamma, and IL-10 (P=0.0001). HIV+ pruritus was significantly highest in TNF-alpha (P=0.0001) staining. HIV+ psoriasis represented an intermediate state for all four cytokines. Normal skin adjacent to lesions showed the same relative patterns, with lower intensities. Skin diseases seen frequently in the setting of HIV and immunodeficiency have relatively distinct levels and patterns of cytokine expression that may reflect immune dysfunction, reactivity to HIV and to opportunistic infections. PMID:11016855

Breuer-McHam, J N; Ledbetter, L S; Sarris, A H; Duvic, M

2000-10-01

15

Reduced intraepidermal nerve fiber density in HIV-associated sensory  

E-print Network

diagnostic tool in idiopathic small-fiber sensory neuropathy3,4 and diabetic neuropathy,5 but has not yetReduced intraepidermal nerve fiber density in HIV-associated sensory neuropathy M. Polydefkis, MD nerve fiber (IENF) density in HIV-associated sensory neuropathy (HIV-SN) to measurements of neuropathy

Steinbach, Joe Henry

16

Successful outcome of renal transplantation in a child with HIV-associated nephropathy.  

PubMed

Classical HIV-associated nephropathy (HIVAN) was first described before the advent of highly active antiretroviral therapy in late stages of HIV disease with high viral load and low CD4 cell count. Renal transplantation has been successful in a large series of carefully selected HIV-infected adults, with patient and renal allograft survival approaching those of non-HIV-infected patients. We report the successful outcome of living related renal transplantation in a vertically transmitted HIV-infected 8-year-old girl with end-stage kidney disease on haemodialysis due to HIVAN. The pretransplant preparations and post-transplant care, with particular emphasis on immunosuppression and avoidance of opportunistic infections, are discussed. PMID:25123405

Shroff, Rukshana C; McCulloch, Mignon; Novelli, Vas; Shingadia, Delane; Bradley, Suzanne; Clapson, Margaret; Mamode, Nizam; Marks, Stephen D

2014-11-01

17

Preventing opportunistic infections.  

PubMed

As more drugs are approved for the prevention of opportunistic infections, concerns regarding the benefits and potential risks of these therapies are arising. A synopsis of the data for prophylaxis against opportunistic infections is provided for the following: Pneumocystis carinii pneumonia, fungal infections, Mycobacterium avium complex, cytomegalovirus infections, and toxoplasmosis. General precautions in using preventive medications for people with fewer than 100 CD4 plus cells are highlighted. PMID:11362422

Cheng, B

1995-05-01

18

HIV-associated Kaposi sarcoma in African children.  

PubMed

HIV-associated Kaposi sarcoma (HIV-KS) is common in African countries where HIV infection is pandemic and anti-retroviral medication is not readily available. Human herpesvirus-8 (HHV-8), which is the essential, but not the sole aetiological factor in KS, is endemic in sub-Saharan Africa and is substantially more prevalent in HIV-seropositive than in HIV-seronegative subjects. In children in sub-Saharan Africa, KS, whether it be HIV-KS or African endemic KS is much more prevalent than any other epidemiological forms of KS. In addition, in sub-Saharan children oral KS is common, and the life-expectancy of HIV-seropositive children with KS is short. Since generalized systemic KS is frequently associated with oral HIV-KS, it is advisable to introduce systemic cytotoxic chemotherapy early in the course of oral HIV-KS. Although the introduction of highly active antiretroviral therapy (HAART) brought about a decline in the incidence of HIV-KS worldwide, HIV-KS remains a significant problem in sub-Saharan Africa where the prevalence of HHV-8 infection is high and access to HAART is limited. PMID:20411798

Feller, L; Khammissa, R A G; Gugushe, T S; Chikte, U M E; Wood, N H; Meyerov, R; Lemmer, J

2010-02-01

19

HIV-associated neurocognitive disorders persist in the era of potent antiretroviral therapy  

PubMed Central

Objectives: This is a cross-sectional, observational study to determine the frequency and associated features of HIV-associated neurocognitive disorders (HAND) in a large, diverse sample of infected individuals in the era of combination antiretroviral therapy (CART). Methods: A total of 1,555 HIV-infected adults were recruited from 6 university clinics across the United States, with minimal exclusions. We used standardized neuromedical, psychiatric, and neuropsychological (NP) examinations, and recently published criteria for diagnosing HAND and classifying 3 levels of comorbidity (minimal to severe non-HIV risks for NP impairment). Results: Fifty-two percent of the total sample had NP impairment, with higher rates in groups with greater comorbidity burden (40%, 59%, and 83%). Prevalence estimates for specific HAND diagnoses (excluding severely confounded cases) were 33% for asymptomatic neurocognitive impairment, 12% for mild neurocognitive disorder, and only 2% for HIV-associated dementia (HAD). Among participants with minimal comorbidities (n = 843), history of low nadir CD4 was a strong predictor of impairment, and the lowest impairment rate on CART occurred in the subset with suppressed plasma viral loads and nadir CD4 ?200 cells/mm3 (30% vs 47% in remaining subgroups). Conclusions: The most severe HAND diagnosis (HAD) was rare, but milder forms of impairment remained common, even among those receiving CART who had minimal comorbidities. Future studies should clarify whether early disease events (e.g., profound CD4 decline) may trigger chronic CNS changes, and whether early CART prevents or reverses these changes. GLOSSARY ANI = asymptomatic neurocognitive impairment; CART = combination antiretroviral therapy; CHARTER = CNS HIV Antiretroviral Therapy Effects Research; CIDI = Composite International Diagnostic Interview; CLIA = Clinical Laboratory Improvement Amendments; CPE = CNS penetration effectiveness; HAD = HIV-associated dementia; HAND = HIV-associated neurocognitive disorder; IADL = instrumental activities of daily living; LP = lumbar puncture; MND = mild neurocognitive disorder; NP = neuropsychological; PAOFI = Patient's Assessment of Own Functioning Inventory. PMID:21135382

Heaton, R.K.; Clifford, D.B.; Franklin, D.R.; Woods, S.P.; Ake, C.; Vaida, F.; Ellis, R.J.; Letendre, S.L.; Marcotte, T.D.; Atkinson, J.H.; Rivera-Mindt, M.; Vigil, O.R.; Taylor, M.J.; Collier, A.C.; Marra, C.M.; Gelman, B.B.; McArthur, J.C.; Morgello, S.; Simpson, D.M.; McCutchan, J.A.; Abramson, I.; Gamst, A.; Fennema-Notestine, C.; Jernigan, T.L.; Wong, J.; Grant, I.

2010-01-01

20

Trichoderma species — opportunistic, avirulent plant symbionts  

Microsoft Academic Search

Trichoderma spp. are free-living fungi that are common in soil and root ecosystems. Recent discoveries show that they are opportunistic, avirulent plant symbionts, as well as being parasites of other fungi. At least some strains establish robust and long-lasting colonizations of root surfaces and penetrate into the epidermis and a few cells below this level. They produce or release a

Charles R. Howell; Ada Viterbo; Ilan Chet; Matteo Lorito; Gary E. Harman

2004-01-01

21

HIV-associated kidney disease in the context of an aging population.  

PubMed

Acute renal failure and chronic kidney disease are more common in HIV-infected patients compared with the general population. Several studies have shown age to be a risk factor for HIV-associated kidney disease. The improved life expectancy of HIV-infected patients as a result of widespread use of antiretroviral therapy has resulted in progressive aging of HIV cohorts in the developed world, and an increased burden of cardiovascular and kidney disease. Consequently, HIV care increasingly needs to incorporate strategies to detect and manage these non-infectious co-morbidities. PMID:22127033

Naftalin, Claire; Nathan, Bavithra; Hamzah, Lisa; Post, Frank A

2011-12-01

22

HIV-Associated Neurocognitive Disorder: Pathogenesis and Therapeutic Opportunities  

PubMed Central

Human immunodeficiency virus type 1 (HIV) infection presently affects more that 40 million people worldwide, and is associated with central nervous system (CNS) disruption in at least 30% of infected individuals. The use of highly active antiretroviral therapy has lessened the incidence, but not the prevalence of mild impairment of higher cognitive and cortical functions (HIV-associated neurocognitive disorders) as well as substantially reduced a more severe form dementia (HIV-associated dementia). Furthermore, improving neurological outcomes will require novel, adjunctive therapies that are targeted towards mechanisms of HIV-induced neurodegeneration. Identifying such molecular and pharmacological targets requires an understanding of the events preceding irreversible neuronal damage in the CNS, such as actions of neurotoxins (HIV proteins and cellular factors), disruption of ion channel properties, synaptic damage, and loss of adult neurogenesis. By considering the specific mechanisms and consequences of HIV neuropathogenesis, unified approaches for neuroprotection will likely emerge using a tailored, combined, and non-invasive approach. PMID:20396973

Lindl, Kathryn A.; Marks, David R.; Kolson, Dennis L.

2010-01-01

23

HIV-Associated Neurocognitive Disorder (HAND)  

PubMed Central

Summary Neurological involvement in HIV is commonly associated with cognitive impairment. While severe and progressive neurocognitive impairment has become rare in HIV clinics in the era of potent antiretroviral therapy, a majority of HIV patients worldwide perform below expectations on formal neurocognitive tests. Co-morbid conditions contribute to impairment, but they are insufficient to explain the frequency of impairment encountered. HIV disease markers like current viral load and CD4 counts are no longer strongly associated with ongoing impairment on therapy, while cardiovascular disease markers and inflammatory markers appear more closely associated. Novel cerebrospinal fluid and neuroimaging biomarkers are needed to detect and follow impairment. Ongoing research to optimize HIV therapy within the central nervous system, and potentially to intervene in downstream mechanisms of neurotoxicity remain important avenues of future investigation. Ultimately, the full control of virus in the brain is a necessary step in the goal of HIV eradication. Weekly searches of English language publications referring to HIV neurocognitive impairment, HIV neuropathy, HIV myelopathy, HIV dementia, and HIV from 1988 to August 2013 were performed. In addition, the authors’ own files were manually searched. PMID:24156898

Clifford, David B.; Ances, Beau M.

2014-01-01

24

Cardiovascular implications of HIV-associated dyslipidemic lipodystrophy  

Microsoft Academic Search

The emergence of a new metabolic syndrome in patients with HIV infection, termed “HIV-associated dyslipidemic lipodystrophy”\\u000a (HADL), is characterized by central fat redistribution, severe dyslipidemia, and insulin resistance and predisposes to an\\u000a increased risk of cardiovascular disease. The factors promoting the development of cardiovascular disease in this condition\\u000a are not well understood and may involve contributions from antiretroviral drugs and

Rajagopal V. Sekhar; Farook Jahoor; Henry J. Pownall; Christie M. Ballantyne; Ashok Balasubramanyam

2004-01-01

25

The Functional Impact of HIV-Associated Neuropsychological Decline  

Microsoft Academic Search

Briefly, HIV infection is associated with neuropsychological deficits in attention\\/working memory, motor abilities, memory,\\u000a and executive functioning (1–5), which are often attributed to disruptions in frontal-striatal circuitry (3, 6). These HIV-associated deficits generally worsen with infection staging (3) , and decline in psychomotor speed appears to be the most robust (5,7) . Although dementia occurs in a relatively small number

Matthew J. Wright; Ellen Woo; Terry R. Barclay; Charles H. Hinkin

26

Functional Consequences of HIV-Associated Neuropsychological Impairment  

Microsoft Academic Search

This review focuses on the “real world” implications of infection with HIV\\/AIDS from a neuropsychological perspective. Relevant\\u000a literature is reviewed which examines the relationships between HIV-associated neuropsychological impairment and employment,\\u000a driving, medication adherence, mood, fatigue, and interpersonal functioning. Specifically, the relative contributions of medical,\\u000a cognitive, psychosocial, and psychiatric issues on whether someone with HIV\\/AIDS will be able to return to

Ashley A. Gorman; Jessica M. Foley; Mark L. Ettenhofer; Charles H. Hinkin; Wilfred G. van Gorp

2009-01-01

27

HIV-associated cerebral lymphocyte infiltration mimicking vestibular schwannoma  

Microsoft Academic Search

The association of unilateral, rapidly progressive hearing loss, tinnitus and vestibular dysfunction in combination with a\\u000a contrast-enhancing mass within the internal auditory canal on MRI is suggestive of a vestibular schwannoma (VS). We report\\u000a the rare finding of a HIV-associated cerebral lymphocyte infiltration, most probably malignant lymphoma, which was presumed\\u000a initially to be a VS. A 36-year-old male presented with

Gentiana I. Wenzel; Friedrich Götz; Thomas Lenarz; Timo Stöver

2008-01-01

28

Epidemiology, Diagnosis, and Treatment of HIV-Associated Non-Hodgkin Lymphoma in Resource-Limited Settings  

PubMed Central

Lymphoma was a common complication of HIV infection in the pre-antiretroviral era, and the incidence of HIV-associated lymphoma has dropped dramatically since the introduction of combination antiretroviral therapy (cART) in resource-rich regions. Conversely, lymphoma is an increasingly common complication of HIV infection in resource-limited settings where the prevalence of HIV infection is high. Relatively little is known, however, about the true incidence and optimal treatment regimens for HIV-associated lymphoma in resource-poor regions. We review the epidemiology, diagnosis, and treatment of HIV-associated non-Hodgkin lymphoma in developing nations and highlight areas for further research that may benefit care in both settings. Examples include risk modification and dose modification of chemotherapy based on HIV risk factors, improving our understanding of the current burden of disease through national cancer registries, and developing cost-effective hematopathological diagnostic strategies to optimize care delivery and maximize use of available chemotherapy. PMID:22548067

Ulrickson, Matthew; Press, Oliver W.; Casper, Corey

2012-01-01

29

Opportunistic immunisation in hospital  

PubMed Central

AIM—To assess the potential for administering catch up and scheduled immunisations during hospital admission.?METHODS—Immunisation status according to the child's principal carer was checked against official records for 1000 consecutively admitted preschool age children. Junior doctors were instructed to offer appropriate vaccination before discharge, and consultants were asked to reinforce this proactive policy on ward rounds.?RESULTS—Excluding those children who were not fully immunised against pertussis through parental choice, 142 children (14.2%) had missed an age appropriate immunisation and 41 were due a scheduled immunisation. None had a valid contraindication. Only 43 children were offered vaccination on the ward but uptake was 65% in this group.?CONCLUSIONS—Admission to hospital provides opportunities for catch up and routine immunisations and can contribute to the health care of an often disadvantaged group of children. These opportunities are frequently missed. Junior doctors must be encouraged to see opportunistic immunisation as an important part of their routine work.? PMID:10519717

Conway, S

1999-01-01

30

Opportunistic pathogens enriched in showerhead biofilms  

PubMed Central

The environments we humans encounter daily are sources of exposure to diverse microbial communities, some of potential concern to human health. In this study, we used culture-independent technology to investigate the microbial composition of biofilms inside showerheads as ecological assemblages in the human indoor environment. Showers are an important interface for human interaction with microbes through inhalation of aerosols, and showerhead waters have been implicated in disease. Although opportunistic pathogens commonly are cultured from shower facilities, there is little knowledge of either their prevalence or the nature of other microorganisms that may be delivered during shower usage. To determine the composition of showerhead biofilms and waters, we analyzed rRNA gene sequences from 45 showerhead sites around the United States. We find that variable and complex, but specific, microbial assemblages occur inside showerheads. Particularly striking was the finding that sequences representative of non-tuberculous mycobacteria (NTM) and other opportunistic human pathogens are enriched to high levels in many showerhead biofilms, >100-fold above background water contents. We conclude that showerheads may present a significant potential exposure to aerosolized microbes, including documented opportunistic pathogens. The health risk associated with showerhead microbiota needs investigation in persons with compromised immune or pulmonary systems. PMID:19805310

Feazel, Leah M.; Baumgartner, Laura K.; Peterson, Kristen L.; Frank, Daniel N.; Harris, J. Kirk; Pace, Norman R.

2009-01-01

31

Role of Neuroimaging in HIV Associated Neurocognitive Disorders (HAND)  

PubMed Central

HIV enters the brain soon after seroconversion and can cause HIV associated neurocognitive disorders (HAND). While the more severe and progressive forms of HAND are less prevalent due to combination antiretroviral therapy (cART), ~ 40% of HIV-infected (HIV+) patients continue to have cognitive impairment. Some HIV+ individuals who have effective plasma HIV-1 RNA suppression with cART still develop HAND. It is often difficult to diagnose HAND in the outpatient setting as detailed neuropsychological performance testing is required. Additional biomarkers that are relatively easy to obtain and clinically relevant are needed for assessing HIV associated neuropathologic changes. Recently developed non-invasive magnetic resonance imaging (MRI) techniques have great potential to serve as biomarkers. We review the application of some of these neuroimaging techniques [magnetic resonance spectroscopy (MRS), volumetric MRI, diffusion tensor imaging (DTI), functional MRI (fMRI)] in HIV+ individuals. Each of the neuroimaging methods offers unique insight into mechanisms underlying neuroHIV, could monitor disease progression, and may assist in evaluating the efficacy of particular cART regimens. It is hoped that considerable progress will continue to occur such that some of these neuroimaging methods will be incorporated across multiple sites and included in future HAND guidelines. PMID:24715492

Masters, Mary C.; Ances, Beau M.

2014-01-01

32

Treatment of HIV-associated diarrhea with curcumin.  

PubMed

Curcumin is the organic extract of turmeric and possesses known anti-inflammatory properties. Our aim was to explore the utility of curcumin in patients with HIV-associated diarrhea. Eight patients with HIV-associated diarrhea were given a mean daily dose of 1,862 mg of curcumin and followed for a mean of 41 weeks. All had resolution of diarrhea and normalization of stool quality in a mean time of 13 +/- 9.3 days. Mean number of bowel movements per day dropped from 7 +/- 3.6 to 1.7 +/- 0.5. Seven of eight patients had considerable weight gain on curcumin (10.8 +/- 8.9 lbs). Five of six patients had resolution of bloating and abdominal pain. Patients on anti-retroviral therapy experienced no discernible drug interactions, changes in CD(4) count, or changes in HIV viral load while taking curcumin. Curcumin therapy was associated with rapid and complete resolution of diarrhea, substantial weight gain, improvement in the reduction of bloating and abdominal pain. PMID:19051018

Conteas, Chris N; Panossian, Abraham M; Tran, Timothy T; Singh, Hardeep M

2009-10-01

33

Increased cortical expression of FK506 binding protein-51 in HIV-associated neurocognitive disorders.  

PubMed

FK506 binding protein (FKBP)-51 and FKBP52 act as molecular chaperones to control glucocorticoid receptor (GR) sensitivity. Dysregulation of proteins involved in GR-mediated signaling can lead to maladaptive stress response and aging-related cognitive decline. As HIV infection is related to chronic stress, we hypothesized that altered cortical expression of these proteins was associated with HIV-associated neurocognitive disorders (HAND). We used quantitative immunohistochemistry to assess expression levels of these proteins in the mid-frontal gyrus of 55 HIV-infected subjects free of cerebral opportunistic diseases compared to 20 age-matched non-HIV controls. The immunoreactivity normalized to the neuroanatomic area measured (IRn) for FKBP51 was increased in HIV subjects both in the cortex and subcortical white matter (p?

Soontornniyomkij, Virawudh; Everall, Ian P; Moore, David J; Gouaux, Ben; Tatro, Erick T; Gospodarev, Vadim; Masliah, Eliezer; Yin, Nicole S; Vinters, Harry V; Achim, Cristian L

2012-08-01

34

Script Generation of Activities of Daily Living in HIV-associated Neurocognitive Disorders  

PubMed Central

Script generation describes one’s ability to produce complex, sequential action plans derived from mental representations of everyday activities. The aim of this study was to assess the effect of HIV infection on script generation performance. Sixty HIV+ individuals (48% of whom had HIV-associated neurocognitive disorders [HAND]) and 26 demographically comparable HIV? participants were administered a novel, standardized test of script generation, which required participants to verbally generate and organize the necessary steps for completing six daily activities. HAND participants evidenced significantly more total errors, intrusions, and script boundary errors compared to the HIV-sample, indicating difficulties inhibiting irrelevant actions and staying within the prescribed boundaries of scripts, but had adequate knowledge of the relevant actions required for each script. These findings are generally consistent with the executive dysfunction and slowing common in HAND and suggest that script generation may play a role in everyday functioning problems in HIV. PMID:22882813

Scott, J. Cobb; Woods, Steven Paul; Vigil, Ofilio; Heaton, Robert K.; Grant, Igor; Ellis, Ronald J.; Marcotte, Thomas D.

2012-01-01

35

Rodent models for HIV-associated neurocognitive disorders  

PubMed Central

Human immunodeficiency virus (HIV)-associated neurocognitive disorders (HAND) reflect the spectrum of neural impairments seen during chronic viral infection. Current research efforts focus on improving antiretroviral and adjunctive therapies, defining disease onset and progression, facilitating drug delivery, and halting neurodegeneration and viral resistance. As HIV is species-specific, generating disease in small animal models has proved challenging. After two decades of research, rodent HAND models now include those containing a human immune system. Antiviral responses, neuroinflammation and immunocyte blood-brain barrier (BBB) trafficking follow HIV infection in these rodent models. Here, we review these and other rodent models of HAND and discuss their unmet potential in reflecting human pathobiology and in facilitating disease monitoring and therapeutic discoveries. PMID:22305769

Gorantla, Santhi; Poluektova, Larisa; Gendelman, Howard E.

2012-01-01

36

HIV-Associated Histoplasmosis Early Mortality and Incidence Trends: From Neglect to Priority  

PubMed Central

Background Histoplasmosis is an endemic fungal infection in French Guiana. It is the most common AIDS-defining illness and the leading cause of AIDS-related deaths. Diagnosis is difficult, but in the past 2 decades, it has improved in this French overseas territory which offers an interesting model of Amazonian pathogen ecology. The objectives of the present study were to describe the temporal trends of incidence and mortality indicators for HIV-associated histoplasmosis in French Guiana. Methods A retrospective study was conducted to describe early mortality rates observed in persons diagnosed with incident cases of HIV-associated Histoplasma capsulatum var. capsulatum histoplasmosis admitted in one of the three main hospitals in French Guiana between 1992 and 2011. Early mortality was defined by death occurring within 30 days after antifungal treatment initiation. Data were collected on standardized case report forms and analysed using standard statistical methods. Results There were 124 deaths (45.3%) and 46 early deaths (16.8%) among 274 patients. Three time periods of particular interest were identified: 1992–1997, 1998–2004 and 2005–2011. The two main temporal trends were: the proportion of early deaths among annual incident histoplasmosis cases significantly declined four fold (?2, p<0.0001) and the number of annual incident histoplasmosis cases increased three fold between 1992–1997 and 1998–2004, and subsequently stabilized. Conclusion From an occasional exotic diagnosis, AIDS-related histoplasmosis became the top AIDS-defining event in French Guiana. This was accompanied by a spectacular decrease of early mortality related to histoplasmosis, consistent with North American reference center mortality rates. The present example testifies that rapid progress could be at reach if awareness increases and leads to clinical and laboratory capacity building in order to diagnose and treat this curable disease. PMID:25144374

Adenis, Antoine; Nacher, Mathieu; Hanf, Matthieu; Vantilcke, Vincent; Boukhari, Rachida; Blachet, Denis; Demar, Magalie; Aznar, Christine; Carme, Bernard; Couppie, Pierre

2014-01-01

37

Immunocytochemical and virological characteristics of HIV-associated inflammatory myopathies: similarities with seronegative polymyositis.  

PubMed

We performed an immunoperoxidase study on muscle biopsy specimens from 19 patients with polymyositis who were seropositive for human immunodeficiency virus (HIV) (21 specimens) and 5 HIV-seronegative patients with polymyositis and compared the findings. A quantitative analysis of T cells and T-cell subsets, B cells, natural killer cells, interleukin-2 receptor-positive cells, and macrophages was performed on serial sections from all the specimens. Localization of major histocompatibility complex (MHC)-I and -II antigens, alpha and gamma interferon, and HIV antigens (p24, gp120, and gp41) was performed using specific antisera. In specimens from HIV-positive and seronegative patients, the predominant cell population was CD8+ cells and macrophages invading or surrounding healthy muscle fibers that expressed MHC-I antigen on their surface. The endomysial infiltrates in specimens from HIV-positive patients differed from those seen in specimens from the seronegative patients only by a significant reduction of the CD4+ cells (12.6 +/- 3.2% versus 21.1 +/- 4.2%). HIV antigens were seen in occasional interstitial mononuclear cells (but not in muscle fibers) in 6 of the 21 specimens from HIV-positive patients. Interferon was not localized. We conclude that the development of HIV-associated polymyositis does not appear to be related to direct infection of the muscle fibers by HIV but rather is due to a T-cell-mediated and MHC-I-restricted cytotoxic process, perhaps triggered by HIV. Because this immunopathological mechanism is common in both HIV-associated polymyositis and polymyositis alone, it is suggested that viruses may also be responsible in triggering polymyositis. PMID:1859178

Illa, I; Nath, A; Dalakas, M

1991-05-01

38

Overview of opportunistic fungal infections in India.  

PubMed

In recent years fungi have been flourishing in immunocompromised patients of tertiary care centers. The data on the burden of opportunistic mycoses in India is not clear though the climate in this country is well suited for a wide variety of fungal infections. There are very few good diagnostic mycology laboratories and clinicians are still not aware of the emerging trends. Within the limited data available, an increased incidence of invasive candidiasis, aspergillosis, and zygomycosis are reported. The emergence of fungal rhinosinusitis, penicilliosis marneffei and zygomycosis due to Apophysomyces elegans is unique in the Indian scenario. Invasive candidiasis is the most common opportunistic mycosis. The global change in spectrum of Candida species is also observed in India; however, the higher prevalence of candidemia due to Candida tropicalis instead of C. glabrata or C. parapsilosis is interesting. Invasive aspergillosis is the second contender. Though due to difficulty in antemortem diagnosis the exact prevalence of this disease is not known, high prevalence is expected in Indian hospitals where construction activities continue in the hospital vicinity without a proper impervious barrier. The other opportunistic mycosis, invasive zygomycosis is an important concern as the world's highest number of cases of this disease is reported from India. The infection is commonly observed in patients with uncontrolled diabetes mellitus. Though antiretroviral therapy in AIDS patients has been introduced in most Indian hospitals, no decline in the incidence of cryptococcosis and penicilliosis has yet been observed. Thus there is need of good diagnostic mycology laboratories, rapid diagnosis, and refinement of antifungal strategies in India. PMID:18689964

Chakrabarti, Arunaloke; Chatterjee, Shiv Sekhar; Shivaprakash, M R

2008-01-01

39

Opportunistic Software Deployment in Disconnected  

E-print Network

Opportunistic Software Deployment in Disconnected Mobile Ad Hoc Networks Fr�d�ric Guidec, Nicolas presents a middleware platform allowing the dissemination of software com- ponents on handheld devices repository with software components so as to be able to satisfy the deployment requests ex- pressed

Paris-Sud XI, Université de

40

Opportunistic Reuse: Lessons from Scrapheap Software Development  

Microsoft Academic Search

Abstract. Many organizations use opportunistic reuse as a low-cost mechanism to improve the efficiency of development. Scrapheap reuse is a particular form of opportunistic development that we explore in this paper with the aid of an experimental study.

Gerald Kotonya; Simon Lock; John Mariani

2008-01-01

41

OPPORTUNISTIC ORGANISMS AND THE WATER SUPPLY CONNECTION  

EPA Science Inventory

Organisms that established in water supply may also be opportunistic pathogens. epresentative opportunistic pathogens that are waterborne include acid-fast bacteria, fecal klebsiellae, Legionella and Pseudomonas aeruginosa. hese organisms may be found in the heterotroph ic bacter...

42

Prepulse Inhibition in HIV-Associated Neurocognitive Disorders  

PubMed Central

Sensorimotor inhibition, or the ability to filter out excessive or irrelevant information, theoretically supports a variety of higher-level cognitive functions. Impaired inhibition may be associated with increased impulsive and risky behavior in everyday life. Individuals infected with HIV frequently show impairment on tests of neurocognitive function, but sensorimotor inhibition in this population has not been studied and may be a contributor to the profile of HIV-associated Neurocognitive Disorders (HAND). 37 HIV-infected individuals (15 with HAND) and 48 non-infected comparison subjects were assessed for prepulse inhibition (PPI), an eyeblink startle paradigm measuring sensorimotor gating. Although HIV status alone was not associated with PPI deficits, HIV-positive participants meeting criteria for HAND showed impaired PPI compared to cognitively intact HIV-positive subjects. In HIV-positive subjects, PPI was correlated with working memory but was not associated with antiretroviral therapy or illness factors. In conclusion, sensorimotor disinhibition in HIV accompanies deficits in higher-order cognitive functions, though the causal direction of this relationship requires investigation. Subsequent research on the role of sensorimotor gating on decision-making and risk behaviors in HIV may be indicated. PMID:23552464

Minassian, Arpi; Henry, Brook L.; Woods, Steven Paul; Vaida, Florin; Grant, Igor; Geyer, Mark A.; Perry, William

2013-01-01

43

Cannabinoid receptor-2 and HIV-associated neurocognitive disorders.  

PubMed

Despite the wide spread use of highly active antiretroviral therapy (HAART), mild forms of HIV-associated neuro cognitive disorders (HAND) remain commonplace. HAART treated patients now show low levels of viremia and more subtle yet biologically important signs of brain macrophage and microglial activation. Adjunctive therapeutic strategies are required to eliminate HIV-1 infection and suppress immune activation and its associated neuroinflammation. In this regard, cannabinoid receptor-2(CB2) activation is a promising means to attenuate HAND by inhibiting HIV replication, down regulating inflammation, and suppressing chemokine-like activity of viral neurotoxic proteins (for example, Tat and HIV-1gp120), and thereby prevent neuronal and synaptic loss. Inhibiting even low level HIV replication can attenuate neuronal injury by decreasing the production of neurotoxins. Down regulation of inflammation by CB2 activation is mediated through blunted activation of peri vascular macrophages and microglia; decreased production of tumor necrosis factor-?, chemokines and virotoxins. Down regulated neuroinflammation can decrease blood brain barrier permeability and leukocyte infiltration resulting in reduced neuronal injury. It is suggested that CB2 agonists may further attenuate HAND in HIVinfected patients on HAART. In addition, CB2 activation may also blunt brain injury by attenuating drug addiction. PMID:25015040

Purohit, Vishnudutt; Rapaka, Rao S; Rutter, Joni

2014-09-01

44

Stenotrophomonas maltophilia: an Emerging Global Opportunistic Pathogen  

PubMed Central

Summary: Stenotrophomonas maltophilia is an emerging multidrug-resistant global opportunistic pathogen. The increasing incidence of nosocomial and community-acquired S. maltophilia infections is of particular concern for immunocompromised individuals, as this bacterial pathogen is associated with a significant fatality/case ratio. S. maltophilia is an environmental bacterium found in aqueous habitats, including plant rhizospheres, animals, foods, and water sources. Infections of S. maltophilia can occur in a range of organs and tissues; the organism is commonly found in respiratory tract infections. This review summarizes the current literature and presents S. maltophilia as an organism with various molecular mechanisms used for colonization and infection. S. maltophilia can be recovered from polymicrobial infections, most notably from the respiratory tract of cystic fibrosis patients, as a cocolonizer with Pseudomonas aeruginosa. Recent evidence of cell-cell communication between these pathogens has implications for the development of novel pharmacological therapies. Animal models of S. maltophilia infection have provided useful information about the type of host immune response induced by this opportunistic pathogen. Current and emerging treatments for patients infected with S. maltophilia are discussed. PMID:22232370

2012-01-01

45

ColoPlus, a new product based on bovine colostrum, alleviates HIV-associated diarrhoea  

Microsoft Academic Search

Objective. HIV-associated diarrhoea occurs in nearly all patients with acquired immunodeficiency syndrome (AIDS) in the developing countries. Diarrhoea is caused by the HIV-related immune dysfunction and is pivotal in the decrease of the helper T-cell (CD4? \\/) population. Enteric pathogens in HIV-associated diarrhoea are, for example, Cryptosporidium, Amoeba and Campylobacter species. Bovine colostrum is the first milk the suckling calf

Claes-Henrik Florén; Sonny Chinenye; Lidia Elfstrand; Conny Hagman; Ingemar Ihse

2006-01-01

46

Cannabis in painful HIV-associated sensory neuropathy: A randomized placebo-controlled trial  

Microsoft Academic Search

Objective: To determine the effect of smoked cannabis on the neuropathic pain of HIV-associated sensory neuropathy and an experimental pain model. Methods: Prospective randomized placebo-controlled trial conducted in the inpatient General Clinical Research Center between May 2003 and May 2005 involving adults with painful HIV- associated sensory neuropathy. Patients were randomly assigned to smoke either cannabis (3.56% tetrahydrocannabinol) or identical

D. I. Abrams; C. A. Jay; S. B. Shade; H. Vizoso; H. Reda; M. E. Kelly; M. C. Rowbotham; K. L. Petersen

2007-01-01

47

Host genetic factors predisposing to HIV-associated neurocognitive disorder.  

PubMed

The success of combination antiretroviral therapy (cART) in transforming the lives of HIV-infected individuals with access to these drugs is tempered by the increasing threat of HIV-associated neurocognitive disorders (HAND) to their overall health and quality of life. Intensive investigations over the past two decades have underscored the role of host immune responses, inflammation, and monocyte-derived macrophages in HAND, but the precise pathogenic mechanisms underlying HAND remain only partially delineated. Complicating research efforts and therapeutic drug development are the sheer complexity of HAND phenotypes, diagnostic imprecision, and the growing intersection of chronic immune activation with aging-related comorbidities. Yet, genetic studies still offer a powerful means of advancing individualized care for HIV-infected individuals at risk. There is an urgent need for 1) longitudinal studies using consistent phenotypic definitions of HAND in HIV-infected subpopulations at very high risk of being adversely impacted, such as children, 2) tissue studies that correlate neuropathological changes in multiple brain regions with genomic markers in affected individuals and with changes at the RNA, epigenomic, and/or protein levels, and 3) genetic association studies using more sensitive subphenotypes of HAND. The NIH Brain Initiative and Human Connectome Project, coupled with rapidly evolving systems biology and machine learning approaches for analyzing high-throughput genetic, transcriptomic and epigenetic data, hold promise for identifying actionable biological processes and gene networks that underlie HAND. This review summarizes the current state of understanding of host genetic factors predisposing to HAND in light of past challenges and suggests some priorities for future research to advance the understanding and clinical management of HAND in the cART era. PMID:24996618

Kallianpur, Asha R; Levine, Andrew J

2014-09-01

48

Current knowledge on HIV-associated Plasmablastic Lymphoma  

PubMed Central

HIV-associated PBL is an AIDS-defining cancer, classified by WHO as a distinct entity of aggressive DLBCL. To date less than 250 cases have been published, of them 17 are pediatric. The pathogenesis of this rare disease is related to immunodeficiency, chronic immune stimulation and EBV. Clinically is a rapid growing destructive disease mainly involving the oral cavity even if extraoral and extranodal sites are not infrequent. The diagnosis requires tissue mass or lymph node biopsy and core needle or fine needle biopsy is acceptable only for difficult access sites. Classically immunophenotype is CD45, CD20, CD79a negative and CD38, CD138, MUM1 positive, EBER and KI67 is >80%. Regarding the therapy, standard treatment is, usually, CHOP or CHOP-like regimens while more intensive regimens as CODOX-M/IVAC or DA-EPOCH are possible options. Use of cART is recommended during chemotherapy, keeping in mind the possible overlapping toxicities. Rituximab is not useful for this CD20 negative disease and CNS prophylaxis is mandatory. Intensification with ABMT in CR1 may be considered for fit patients. For refractory/relapsed patients, therapy is, usually, considered palliative, however, in chemo-sensitive disease, intensification + ABMT or new drugs as Bortezomib may be considered. Factors affecting outcome are achieving complete remission, PS, clinical stage, MYC, IPI score. Reported median PFS ranges between 6–7 months and median OS ranges between 11–13 months. Long term survivors are reported but mostly in pediatric patients. Finally, due to the scarcity of data on this subtype of NHL we suggest that the diagnosis and the management of HIV-positive PBL patients should be performed in specialized centers. PMID:25408850

Bibas, Michele; Castillo, Jorge J.

2014-01-01

49

REMOTE DETECTION OF INVASSIVE AND OPPORTUNISTIC PLANT SPECIES IN GREAT LAKES COASTAL WETLANDS  

EPA Science Inventory

Invasive and opportunistic plant species have been associated with wetland disturbance. Increases in the abundance of plant species such as common reed (Phragmites australis) in coastal Great Lakes wetlands are hypothesized to occur with shifts toward drier hydrologic regimes, fr...

50

REMOTE DETENTION OF INVASIVE AND OPPORTUNISTIC PLANT SPECIES IN GREAT LAKES COASTAL WETLANDS  

EPA Science Inventory

Invasive and opportunistic plant species have been associated with wetland disturbance. Increases in the abundance of plant species such as common reed (Phragmites australis) in coastal Great Lakes wetlands are hypothesized to occur with shifts toward drier hydrologic regimes, fr...

51

Fc Gamma Receptor 3A Polymorphism and Risk for HIV-Associated Cryptococcal Disease  

PubMed Central

ABSTRACT Cryptococcus neoformans is one of the most common causes of fungal disease in HIV-infected persons, but not all of those who are infected develop cryptococcal disease (CD). Although CD4+ T cell deficiency is a risk factor for HIV-associated CD, polymorphisms of phagocytic Fc gamma receptors (FCGRs) have been linked to CD risk in HIV-uninfected persons. To investigate associations between FCGR2A 131 H/R and FCGR3A 158 F/V polymorphisms and CD risk in HIV-infected persons, we performed PCR-based genotyping on banked samples from 164 men enrolled in the Multicenter AIDS Cohort Study (MACS): 55 who were HIV infected and developed CD and a matched control group of 54 who were HIV infected and 55 who were HIV uninfected. Using additive and allelic statistical models for analysis, the high-affinity FCGR3A 158V allele was significantly associated with CD status after adjusting for race/ethnicity (odds ratio [OR], 2.1; P = 0.005), as was the FCGR3A 158 VV homozygous genotype after adjusting for race/ethnicity, rate of CD4+ T cell decline, and nadir CD4+ T cell count (OR, 21; P = 0.005). No associations between CD and FCGR2A 131 H/R polymorphism were identified. In binding studies, human IgG (hIgG)-C. neoformans complexes exhibited more binding to CHO-K1 cells expressing FCGR3A 158V than to those expressing FCGR3A 158F, and in cytotoxicity assays, natural killer (NK) cells expressing FCGR3A 158V induced more C. neoformans-infected monocyte cytotoxicity than those expressing FCGR3A 158F. Together, these results show an association between the FCGR3A 158V allele and risk for HIV-associated CD and suggest that this polymorphism could promote C. neoformans pathogenesis via increased binding of C. neoformans immune complexes, resulting in increased phagocyte cargo and/or immune activation. PMID:23982074

Rohatgi, Soma; Gohil, Shruti; Kuniholm, Mark H.; Schultz, Hannah; Dufaud, Chad; Armour, Kathryn L.; Badri, Sheila; Mailliard, Robbie B.; Pirofski, Liise-anne

2013-01-01

52

HIV-Associated TB in An Giang Province, Vietnam, 2001– 2004: Epidemiology and TB Treatment Outcomes  

E-print Network

Background. Mortality is high in HIV-infected TB patients, but few studies from Southeast Asia have documented the benefits of interventions, such as co-trimoxazole (CTX), in reducing mortality during TB treatment. To help guide policy in Vietnam, we studied the epidemiology of HIV-associated TB in one province and examined factors associated with outcomes, including the impact of CTX use. Methodology/Principal Findings. We retrospectively abstracted data for all HIV-infected persons diagnosed with TB from 2001–2004 in An Giang, a province in southern Vietnam in which TB patients receive HIV counseling and testing. We used standard WHO definitions to classify TB treatment outcomes. We conducted multivariate analysis to identify risk factors for the composite outcome of death, default, or treatment failure during TB treatment. From 2001–2004, 637 HIV-infected TB patients were diagnosed in An Giang. Of these, 501 (79%) were male, 321 (50%) were aged 25–34 years, and the most common self-reported HIV risk factor was sex with a commercial sex worker in 221 (35%). TB was classified as smear-positive in 531 (83%). During TB treatment, 167 (26%) patients died, 9 (1%) defaulted, and 6 (1%) failed treatment. Of 454 patients who took CTX, 116 (26%) had an unsuccessful outcome compared with 33 (70%) of 47 patients who did not take CTX (relative risk, 0.4; 95 % confidence interval [CI], 0.3–0.5). Adjusting for male sex, rural residence, TB smear status and

Trinh Thanh Thuy; N. Sarita Shah; Mai Hoang Anh; Do Trong Nghia; Duong Thom; Truong Linh; Dinh Ngoc Sy; Bui Duc Duong; Luu Thi; Minh Chau; Phung Thi; Phuong Mai; Charles D. Wells; Kayla F. Laserson; Jay K. Varma

53

An Unusual Case of Anti-GBM Antibody Elevation in HIV-Associated Nephropathy  

PubMed Central

Introduction. The most commonly seen glomerular disease in HIV infected patients is HIV-associated nephropathy (HIVAN); however, a multitude of other nephropathies can occur in HIV infection with an almost equal cumulative frequency. We report an unusual case of a patient with clinical and histological evidence of HIVAN in which the diagnosis was initially confounded by the finding of an elevated serum anti-glomerular basement membrane (anti-GBM) antibody. Case Presentation. We present a case of a 27-year-old African American female with a history of schizophrenia, cocaine abuse, and HIV infection who upon admission to our hospital was found to have severe acute kidney injury requiring hemodialysis. Urine studies revealed nephrotic range proteinuria and a serological workup was positive for anti-GBM antibody elevation with a value of 91 units (normal: 0–20 units). A renal biopsy revealed HIVAN with no evidence of crescentic glomerulonephritis or anti-GBM disease. Conclusion. This case highlights the need for careful interpretation of anti-GBM antibody tests in HIV infected patients with kidney disease and, in particular, the need for biopsy confirmation of the diagnosis prior to starting therapy. More research is needed to study the prognostic correlation between the degree of anti-GBM antibody elevation in HIVAN and disease severity. PMID:24995137

Makary, Raafat; Poenariu, Andreea

2014-01-01

54

Heel pain and HIV-associated lipodystrophy: a report of two cases  

PubMed Central

Plantar fasciitis is diagnosed based on a pathognomonic clinical presentation and physical examination including plantar heel pain with the initial few steps after a period of inactivity. People living with HIV/AIDS, who are taking anti-retroviral medications, often have an associated redistribution of body fat (lipodystrophy). Lipoatrophy of the extremities may involve the heel fat-pad in this population and result in the signs and symptoms of plantar fasciitis. Two cases of plantar heel pain in HIV-associated lipodystrophy are presented to discuss the possible clinical association between the two conditions. Although conservative therapies have limited evidence, they are commonly used and have been seen, clinically, to result in a resolution of symptoms. In the presented cases, the individuals benefited from soft tissue therapy, modalities, activity modification and education on proper footwear. Clinicians should be aware that the association between these two conditions may be a significant cause of morbidity in a population of patients with HIV. PMID:18516231

Stupar, Maja; Tibbles, Anthony

2008-01-01

55

Selegiline and oxidative stress in HIV-associated cognitive impairment  

PubMed Central

Objective: To assess the effectiveness of the selegiline transdermal system (STS) in reversing HIV-induced metabolic brain injury (as measured by proton magnetic resonance spectroscopy [MRS]) and in decreasing oxidative stress, measured by CSF protein carbonyl concentration. Methods: Sixty-two subjects with HIV-associated cognitive impairment were coenrolled in a 24-week placebo-controlled study (AIDS Clinical Trial Group protocol A5090) and were randomly assigned to receive STS 3 mg/24 h, STS 6 mg/24 h, or matching placebo. Cognitive performance was evaluated using the neuropsychological z score (NPZ)-8 and NPZ-6, as well as cognitive domain scores. Subjects underwent proton MRS at study entry and weeks 12 and 24. CSF protein carbonyl was measured at baseline and week 24. Results: A slight increase in N-acetyl aspartate/creatine from baseline to week 24 was found in the basal ganglia (p = 0.023) and centrum semiovale (p = 0.072) of the placebo group compared with the STS groups; however, there were no significant changes when the absolute metabolite concentrations were analyzed. The levels of choline/creatine in the midfrontal cortex were also significantly higher during the week 12 visit in the combined STS groups. This persisted to the week 24 visit (p = 0.002). Evaluation of the change in NPZ-8, NPZ-6, and cognitive domain scores from baseline to weeks 12 and 24 revealed no significant differences between treatment arms. Protein carbonyl analysis revealed no significant changes among the groups. Conclusion: In this 24-week study, the selegiline transdermal system (STS) had no effect on either magnetic resonance spectroscopy (MRS) metabolites or oxidative stress, as measured by CSF protein carbonyl concentration. The lack of effect on these biomarkers is also reflected in the lack of cognitive improvement in the STS groups compared to placebo. Level of evidence: This study provides Class II evidence that STS had no effect on either MRS metabolites or oxidative stress, as measured by CSF protein carbonyl concentration over a period of 24 weeks. GLOSSARY ADC = dementia complex; Cho = choline; Cr = creatine; DNPH = 2,4-dinitrophenylhydrazine; FOV = field of view; Glx = glutamate/glutamine; HAART = highly active antiretroviral therapy; MI = myoinositol; MRS = magnetic resonance spectroscopy; NAA = N-acetylaspartate; NEX = number of excitations; NPZ = neuropsychological z score; PBS = phosphate-buffered saline; SNR = signal-to-noise ratio; STS = selegiline transdermal system; TE = echo time; TR = repetition time. PMID:19890073

Schifitto, G; Yiannoutsos, C T.; Ernst, T; Navia, B A.; Nath, A; Sacktor, N; Anderson, C; Marra, C M.; Clifford, D B.

2009-01-01

56

Migration and opportunistic feeding increase PCB accumulation in Arctic seabirds.  

PubMed

It is widely accepted that body concentrations of persistent organic pollutants (POPs) tend to increase with trophic level (TL). Yet, little attention has been paid to the causes in the underlying differences in POP body concentrations between species occupying similar TLs. In this paper we use two modeling approaches to quantify the importance of migration and opportunistic feeding, relative to that of trophic level, in explaining interspecific differences in polychlorinated biphenyl (PCB) body concentrations between 6 Arctic seabird species breeding in the Barents Sea: Little Auk (Alle alle), Black Guillemot (Cepphus grylle), Brünnich's Guillemot (Uria lomvia), Common Eider (Somateria mollissima), Black-legged Kittiwake (Rissa tridactyla), and Glaucous Gull (Larus hyperboreus). As a first approach, we use additive models to analyze two independent data sets (n = 470 and n = 726). We demonstrate that migration, opportunistic feeding, and TL significantly (p < 0.001) increase PCB body concentrations by a factor 3.61-4.10, 2.66-20.95, and 2.38-2.41, respectively. Our second approach, using a mechanistic bioaccumulation model, confirmed these positive effects on the body burdens but suggested lower effects of migration, opportunistic feeding, and TL (1.55, 2.39, and 2.38) than did our statistical analysis. These two independent approaches demonstrate that the effects of migration and opportunistic feeding on seabird body burdens can be similar to that of an increase of one TL and should therefore be accounted for in future analyses. PMID:24024972

Baert, J M; Janssen, C R; Borgå, K; De Laender, F

2013-10-15

57

Mobile Opportunistic Planning: Methods and Models  

Microsoft Academic Search

We present a study exploring the promise of develo ping computa- tional systems to support the discovery and executi on of opportunistic activities in mobile settings. We introduce the challenge of mobile opportunistic plan- ning, describe a prototype named Mobile Commodities , and focus on the con- struction and use of probabilistic user models to i nfer the cost of

Eric Horvitz; Paul Koch; Muru Subramani

2007-01-01

58

Design Principles for Robust Opportunistic Communication  

E-print Network

Design Principles for Robust Opportunistic Communication S. Keshav David R. Cheriton School energy and bandwidth usage costs by exploiting transient communication opportunities. We argue that this opportunistic communication mode will play a significant role in future mobile communication systems. We present

Waterloo, University of

59

Opportunistic Spectrum Access in Cognitive Radio Networks  

Microsoft Academic Search

Enabled by regulatory initiatives and radio technol- ogy advances, opportunistic spectrum access has the potential to mitigate spectrum scarcity and satisfy the increasing demand for spectrum. In this paper, we consider a scenario where secondary users can opportunistically access unused spectrum vacated by idle primaries. We introduce two metrics to protect primary performance, namely collision probability and overlapping time. We

Senhua Huang; Xin Liu; Zhi Ding

2008-01-01

60

Antiretroviral medications disrupt microglial phagocytosis of ?-amyloid and increase its production by neurons: implications for HIV-associated neurocognitive disorders.  

PubMed

Up to 50% of long-term HIV infected patients, including those with systemically well-controlled infection, commonly experience memory problems and slowness, difficulties in concentration, planning, and multitasking. Deposition of A? plaques is also a common pathological feature of HIV infection. However, it is not clear whether this accumulation is due to AD-like processes, HIV-associated immunosuppression, Tat protein-induced A? elevations, and/or the effects of single highly active antiretroviral therapy (ART). Here we evaluated the effects of several ART medications (Zidovudine, Lamivudine, Indinavir, and Abacavir) alone and in combination on: 1) A?1-40, 42 generation in murine N2a cells transfected with the human "Swedish" mutant form of APP; 2) microglial phagocytosis of FITC-A?1-42 peptides in cultured murine N9 microglia. We report for the first time that these antiretroviral compounds (10 ?M) generally increase A? generation (~50-200%) in SweAPP N2a cells and markedly inhibit microglial phagocytosis of FITC-A?1-42 peptides in murine microglia. The most significant amyloidogenic effects were observed with combined ART (p < 0.05); suggesting certain ART medications may have additive amyloidogenic effects when combined. As these antiretroviral compounds are capable of penetrating the blood brain barrier and reaching the concentrations employed in the in vitro studies, these findings raise the possibility that ART may play a casual role in the elevated A? found in the brains of those infected with HIV. Therefore these compounds may consequently contribute to cognitive decline observed in HIV associated neurocognitive disorders (HAND). PMID:21649911

Giunta, Brian; Ehrhart, Jared; Obregon, Demian F; Lam, Lucy; Le, Lisa; Jin, JingJi; Fernandez, Francisco; Tan, Jun; Shytle, R Douglas

2011-01-01

61

Opportunistic tangible user interfaces for augmented reality.  

PubMed

Opportunistic Controls are a class of user interaction techniques that we have developed for augmented reality (AR) applications to support gesturing on, and receiving feedback from, otherwise unused affordances already present in the domain environment. By leveraging characteristics of these affordances to provide passive haptics that ease gesture input, Opportunistic Controls simplify gesture recognition, and provide tangible feedback to the user. In this approach, 3D widgets are tightly coupled with affordances to provide visual feedback and hints about the functionality of the control. For example, a set of buttons can be mapped to existing tactile features on domain objects. We describe examples of Opportunistic Controls that we have designed and implemented using optical marker tracking, combined with appearance-based gesture recognition. We present the results of two user studies. In the first, participants performed a simulated maintenance inspection of an aircraft engine using a set of virtual buttons implemented both as Opportunistic Controls and using simpler passive haptics. Opportunistic Controls allowed participants to complete their tasks significantly faster and were preferred over the baseline technique. In the second, participants proposed and demonstrated user interfaces incorporating Opportunistic Controls for two domains, allowing us to gain additional insights into how user interfaces featuring Opportunistic Controls might be designed. PMID:19910657

Henderson, Steven; Feiner, Steven

2010-01-01

62

Planning for rover opportunistic science  

NASA Technical Reports Server (NTRS)

The Mars Exploration Rover Spirit recently set a record for the furthest distance traveled in a single sol on Mars. Future planetary exploration missions are expected to use even longer drives to position rovers in areas of high scientific interest. This increase provides the potential for a large rise in the number of new science collection opportunities as the rover traverses the Martian surface. In this paper, we describe the OASIS system, which provides autonomous capabilities for dynamically identifying and pursuing these science opportunities during longrange traverses. OASIS uses machine learning and planning and scheduling techniques to address this goal. Machine learning techniques are applied to analyze data as it is collected and quickly determine new science gods and priorities on these goals. Planning and scheduling techniques are used to alter the behavior of the rover so that new science measurements can be performed while still obeying resource and other mission constraints. We will introduce OASIS and describe how planning and scheduling algorithms support opportunistic science.

Gaines, Daniel M.; Estlin, Tara; Forest, Fisher; Chouinard, Caroline; Castano, Rebecca; Anderson, Robert C.

2004-01-01

63

Relationship between lactobacilli and opportunistic bacterial pathogens associated with vaginitis  

PubMed Central

Background: Vaginitis, is an infectious inflammation of the vaginal mucosa, which sometimes involves the vulva. The balance of the vaginal flora is maintained by the Lactobacilli and its protective and probiotic role in treating and preventing vaginal infection by producing antagonizing compounds which are regarded as safe for humans. Aim: The aim of this study was to evaluate the protective role of Lactobacilli against common bacterial opportunistic pathogens in vaginitis and study the effects of some antibiotics on Lactobacilli isolates. Materials and Methods: In this study (110) vaginal swabs were obtained from women suffering from vaginitis who admitted to Babylon Hospital of Maternity and Paediatrics in Babylon province, Iraq. The study involved the role of intrauterine device among married women with vaginitis and also involved isolation of opportunistic bacterial isolates among pregnant and non pregnant women. This study also involved studying probiotic role of Lactobacilli by production of some defense factors like hydrogen peroxide, bacteriocin, and lactic acid. Results: Results revealed that a total of 130 bacterial isolates were obtained. Intrauterine device was a predisposing factor for vaginitis. The most common opportunistic bacterial isolates were Staphylococcus aureus, Escherichia coli, Streptococcus agalactiae, and Klebsiella pneumoniae. All Lactobacilli were hydrogen peroxide producers while some isolates were bacteriocin producers that inhibited some of opportunistic pathogens (S. aureus, E. coli). Lactobacilli were sensitive to erythromycin while 93.3% of them were resistant to ciprofloxacin and (40%, 53.3%) of them were resistant to amoxicillin and gentamycin respectively. Results revealed that there was an inverse relationship between Lactobacilli presence and organisms causing vaginitis. This may be attributed to the production of defense factors by Lactobacilli. Conclusion: The types of antibiotics used to treat vaginitis must be very selective in order not to kill the beneficial bacteria (Lactobacilli) that help in preservation of vaginal health and ecosystem as being one of the probiotic bacteria. PMID:22540089

Razzak, Mohammad Sabri A.; Al-Charrakh, Alaa H.; AL-Greitty, Bara Hamid

2011-01-01

64

Opportunistic, collaborative and synchronized, proximal device ecology  

E-print Network

CoSync is an on-device software framework for coordinating proximal consumer electronic devices in order to create a synchronized, opportunistic and collaborative device ecology. The CoSync device ecology combines multiple ...

Toledano, Eyal

2013-01-01

65

Diagnosis and treatment of HIV-associated manifestations in otolaryngology  

PubMed Central

Almost 30 years after its first description, HIV still remains a global pandemic. The present paper aims to review the current knowledge on the ear, nose and throat (ENT) manifestations of HIV infection, and present the available diagnostic and treatment options. A literature review was conducted in Medline and other available database sources. Information from related books was also included in the data analysis. It is well acknowledged that up to 80% of HIV-infected patients eventually develop ENT manifestations; among which, oral disease appears to be the most common. Oro-pharyngeal manifestations include candidiasis, periodontal and gingival disease, HSV and HPV infection, oral hairy leucoplakia, Kaposi's sarcoma, and non-Hodgkin's lymphoma. ENT manifestations in the neck can present as cervical lymphadenopathy or parotid gland enlargement. Respective nasal manifestations include sinusitis (often due to atypical bacteria), and allergic rhinitis. Finally, otological manifestations include otitis (externa, or media), inner ear involvement (sensorineural hearing loss, disequilibrium), and facial nerve palsy (up to 100 times more frequently compared to the general population). Although ENT symptoms are not diagnostic of the disease, they might be suggestive of HIV infection, or related to its progression and the respective treatment failure. ENT doctors should be aware of the ENT manifestations associated with HIV disease, and the respective diagnosis and treatment. A multi-disciplinary approach may be required to provide the appropriate level of care to HIV patients. PMID:24470939

lacovou, Emily; Vlastarakos, Petros V.; Papacharalampous, George; Kampessis, George; Nikolopoulos, Thomas P.

2012-01-01

66

HIV-associated nephropathy and end-stage renal disease in children in the United States  

Microsoft Academic Search

Single-center studies have reported that HIV-associated nephropathy (HIVAN) can occur in children and may have a clinical course and prognosis similar to that of adults. However, the prevalence and survival has not been reported for a national sample of children with HIVAN and end-stage renal disease (ESRD) on dialysis in the United States. We utilized the United States Renal Data

Tejinder S. Ahuja; Kevin C. Abbott; Laura Pack; Yong-Fang Kuo

2004-01-01

67

RESEARCH Open Access Probabilistic framework for opportunistic  

E-print Network

network performance based only on the local interference measurements at the cognitive senders does as local interference measurements lead to inaccurate spectrum access decisions and (ii) adopts a non approaches. Keywords: Cognitive radio networks, Opportunistic spectrum management, Medium access control 1

Perkins, Dmitri

68

Low Complexity Opportunistic Decoder for Network Coding  

E-print Network

Low Complexity Opportunistic Decoder for Network Coding Bei Yin, Michael Wu, Guohui Wang for network coding decoder which significantly reduces the decoder complexity and increases the through- put transmissions. Although network coding increases the network performance, the complexity of the network coding

Mellor-Crummey, John

69

Hindering Eavesdropping via IPv6 Opportunistic Encryption  

E-print Network

proposal enables the dynamic configu- ration of an encrypted tunnel between the two nodes' IPsec gateways on any global Trusted Third Party (such as DNSSEC or a PKI). The IPsec gateways are discovered using IPv6, IPv6, Opportunistic Encryption, IPsec, CBID, del- egation, IKE. 1 Introduction Because of its massive

Castelluccia, Claude

70

Hindering Eavesdropping via IPv6 Opportunistic Encryption  

Microsoft Academic Search

This paper presents an opportunistic encryption scheme strictly layered on top of IPv6. Assuming that a node needs to send data toward another node, our proposal enables the dynamic configu- ration of an encrypted tunnel between the two nodes' IPsec gateways. The main contribution of this paper is to propose a solution that is fully distributed and does not rely

Claude Castelluccia; Gabriel Montenegro; Julien Laganier; Christoph Neumann

2004-01-01

71

A history of alcohol dependence augments HIV-associated neurocognitive deficits in persons aged 60 and older.  

PubMed

Excessive alcohol use is common among people living with HIV. Given the growing prevalence of older HIV+ adults and observations indicating higher risk for neurocognitive impairment in older adults with either HIV infection or alcoholism, an increased understanding of their combined impact in the context of this increasingly aged population is crucial. We conducted comprehensive neurocognitive assessment in 112 older HIV+ individuals aged 50 to 69 years. Regression analyses were conducted to examine the interaction between age and the presence of lifetime alcohol dependence on neurocognitive measures, controlling for years of education, hepatitis C serostatus, and lifetime non-alcohol substance use disorder. Significant interactions of age and alcohol dependence history were found for global neurocognitive function, which was driven by the domains of executive function, processing speed, and semantic memory. Follow-up analyses indicated adverse effects of alcohol use history on neurocognitive measures that were evident only in HIV+ individuals 60 years and older. While mounting evidence in younger cohorts indicates adverse synergistic HIV/alcohol effects on neurocognitive function, our novel preliminary findings in this elderly HIV+ cohort demonstrated the importance of even a relatively distant alcohol use history on the expression of HIV-associated neurocognitive disorders that may not become apparent until much later in life. PMID:25201556

Gongvatana, Assawin; Morgan, Erin E; Iudicello, Jennifer E; Letendre, Scott L; Grant, Igor; Woods, Steven Paul

2014-10-01

72

BBS-ONE: Bulletin board and forum system for mobile opportunistic networks  

Microsoft Academic Search

Electronic bulletin boards and forum systems are commonly used to exchange opinions, news, event notifications, documents and other media on the Internet. However, such systems usually require a central server hosting the content. Such servers cannot be installed in ad-hoc opportunistic wireless networks, which are created when mobile devices congregate to form a localized and short-lived network without Internet connectivity.

Kiwoon Sung; Suman Srinivasan; Henning Schulzrinne

2010-01-01

73

Draft Genome Sequence of the Rodent Opportunistic Pathogen Pasteurella pneumotropica ATCC 35149T  

PubMed Central

Pasteurella pneumotropica is an opportunistic pathogen in rodents that is commonly isolated from upper respiratory tracts in laboratory rodents. Here, we report the draft genome sequence of the P. pneumotropica type strain ATCC 35149, which was first isolated and characterized as biotype Jawetz. PMID:25103762

Ishikawa, Hiroki; Asano, Ryoki; Ueshiba, Hidehiro; Matsumoto, Tetsuya; Boot, Ron

2014-01-01

74

Risk indicators for HIV-associated jointly occurring oral candidiasis and oral hairy leukoplakia.  

PubMed

Joint occurrence of two or more diseases may impact their transmission, clinical presentation, management approaches, and treatment efficacy. Although oral candidiasis (OC) and oral hairy leukoplakia (OHL) are the most commonly occurring opportunistic oral diseases of HIV-infected patients, literature describing their joint occurrence is sparse. The purpose of this project was to develop an explanatory multivariable model for joint occurrence of OC and OHL (OC-OHL). This cross-sectional study examined 631 adult dentate HIV-1 seropositive persons for OC and OHL from 1995-2000 at the University of North Carolina Hospitals in Chapel Hill, NC. Data collected from medical record review, interviews and clinical examinations were analyzed using chi(2) tests, t itests, and nonparametric tests. Multivariable proportional odds models were developed, using the likelihood ratio test and adjusting for several demographic, behavioral, and biological factors. Thirteen percent of participants had OC only; 12.8% had OHL only; 4.6% had OC-OHL; whereas 69.7% had neither. Occurrence of OC-OHL was independently associated with CD4+ counts less than 200 cells per microliter (adjusted odds ratio [OR] (95% confidence interval {CI}) = 13.4 (6.6, 27.2) and CD4+ counts 200-499 cells per microliter (OR = 3.9 [1.9, 8.1]); current smokers (OR = 2.3 [1.4, 3.8]); and whites (OR = 1.7 [1.1, 2.5]). Combination antiretroviral therapy was protective (OR = 0.5 [0.3, 0.9]). In an HIV-1-infected population, lower CD4+ cell counts and smoking were important independent risk indicators for joint occurrence of OC and OHL. PMID:18240892

Chattopadhyay, Amit; Patton, Lauren L

2007-11-01

75

Medical Marijuana for HIV-Associated Sensory Neuropathy: Legal and Ethical Issues.  

PubMed

The number of states legalizing medical marijuana is increasing. Medical marijuana is possibly effective therapy for HIV-associated sensory neuropathy. Despite legalization at the state level, however, the current and contradictory federal drug enforcement policy creates the risk that physicians who recommend medical marijuana to their patients will lose their ability to prescribe medications. The federal-state tension has legal and ethical implications for neurologists who receive a request for medical marijuana from their patients since neurologists must strive to both relieve suffering and obey relevant laws. Recommendation of medical marijuana by neurologists to their patients is ethically permissible but is not ethically mandatory. PMID:25299291

Larriviere, Daniel G

2014-10-01

76

HIV-associated adipose redistribution syndrome (HARS): etiology and pathophysiological mechanisms  

PubMed Central

Human immunodeficiency virus (HIV)-associated adipose redistribution syndrome (HARS) is a fat accumulation disorder characterized by increases in visceral adipose tissue. Patients with HARS may also present with excess truncal fat and accumulation of dorsocervical fat ("buffalo hump"). The pathophysiology of HARS appears multifactorial and is not fully understood at present. Key pathophysiological influences include adipocyte dysfunction and an excessive free fatty acid release by adipocyte lipolysis. The contributory roles of free fatty acids, cytokines, hormones including cortisol, insulin and the growth hormone-adipocyte axis are significant. Other potential humoral, paracrine, endocrine, and neural influences are also discussed. PMID:17597538

Lichtenstein, Kenneth; Balasubramanyam, Ashok; Sekhar, Rajagopal; Freedland, Eric

2007-01-01

77

Opportunistic migration in spatial evolutionary games  

NASA Astrophysics Data System (ADS)

We study evolutionary games in a spatial diluted grid environment in which agents strategically interact locally but can also opportunistically move to other positions within a given migration radius. Using the imitation of the best rule for strategy revision, it is shown that cooperation may evolve and be stable in the Prisoner's Dilemma game space for several migration distances but only for small game interaction radius while the Stag Hunt class of games become fully cooperative. We also show that only a few trials are needed for cooperation to evolve, i.e., searching costs are not an issue. When the stochastic Fermi strategy update protocol is used cooperation cannot evolve in the Prisoner's Dilemma if the selection intensity is high in spite of opportunistic migration. However, when imitation becomes more random, fully or partially cooperative states are reached in all games for all migration distances tested and for short to intermediate interaction radii.

Buesser, Pierre; Tomassini, Marco; Antonioni, Alberto

2013-10-01

78

Information Spreading in Opportunistic Networks is Fast  

E-print Network

Performance bounds for opportunistic networks have been derived in a number of recent papers for several key quantities, such as the expected delivery time of a unicast message, or the flooding time, i.e., the time needed to deliver a message to all nodes in the network. However, to the best of our knowledge, none of the existing results is based on "realistic" mobility models, where "realistic" refers to a mobility model which is able to accurately reproduce the power law+exponential tail dichotomy of the pairwise node inter-meeting time distribution which has been observed in several real world traces. The contributions of this paper are three-fold: first, we present a simple link model -- called the Home-MEG model -- for opportunistic networks based on the notion of a home location derived in previous works, and we show through extensive comparison with real-world traces that the Home-MEG model is "realistic". Second, we use the Home-MEG model to analyze flooding time in opportunistic networks, presenting ...

Becchetti, Luca; Pasquale, Francesco; Resta, Giovanni; Santi, Paolo; Silvestri, Riccardo

2011-01-01

79

HIV-associated Deficits in Action (Verb) Generation May Reflect Astrocytosis  

PubMed Central

Commensurate with the hypothesized neural dissociation between verb and noun generation, research in HIV infection shows that, relative to noun fluency, action (verb) fluency is disproportionately impaired, more strongly related to executive dysfunction, and more sensitive to declines in everyday functioning. However, whether the neurobiological correlates of HIV-associated deficits in verb and noun generation are separable have not heretofore been investigated. The present study examined the biomarker correlates of action and noun fluency in 74 participants with HIV infection. Biomarkers of viral burden, neuroaxonal damage, macrophage activation, neuroprotection, inflammation, and astrocytosis were measured in plasma and cerebrospinal fluid (CSF). Deficits in action, but not noun generation, were significantly associated with higher CSF levels of S100?, a marker of astrocyte activation, even after controlling for antiretroviral therapy, current immune compromise, and general cognitive impairment. Concurrent validity for the frontal systems hypothesis of verb generation was provided by post-hoc analyses demonstrating that S100? was also associated with measures of executive functions, but not semantic memory or psychomotor speed. Overall, these findings suggest that HIV-associated impairment in action fluency, and executive dysfunction more generally, may reflect astrocytosis (i.e., elevated S100 ?). Complementing the literature in HIV and other clinical populations with frontal systems involvement, these data also support the possible neurobiological dissociation of noun and verb generation. PMID:19844819

Woods, Steven Paul; Iudicello, Jennifer E.; Dawson, Matthew S.; Weber, Erica; Grant, Igor; Letendre, Scott L.

2009-01-01

80

Cognitive Neurorehabilitation of HIV-associated Neurocognitive Disorders: A Qualitative Review and Call to Action  

PubMed Central

Despite significant advances in the virologic management of HIV infection over the last two decades, effective treatments for HIV-associated neurocognitive disorders (HAND) remain elusive. While pharmacological interventions have yielded some success in improving neurocognitive outcomes in HIV, there is a dearth of rigorous studies examining the efficacy of cognitive rehabilitation for remediating HIV-associated neurocognitive impairment. This qualitative review summarizes and critiques the emerging literature on cognitive and behavioral treatments for HAND, which provides many reasons for optimism, but also has major limitations that underscore the scope of the work that lies ahead. Considering the notable real-world consequences of HAND, the development, validation, and clinical deployment of cognitive neurorehabilitation interventions tailored to the needs of persons living with HIV infection is a priority for clinical neuroAIDS investigators. In describing potential future directions for this endeavor, particular attention was paid to the application of cognitive neuropsychological principles in developing theory-driven approaches to managing HAND, improving everyday functioning, and enhancing HIV health outcomes. PMID:23417497

Weber, Erica; Blackstone, Kaitlin; Woods, Steven Paul

2013-01-01

81

Human immunodeficiency virus (HIV)-associated extranodal T cell non-Hodgkin lymphoma of the oral cavity.  

PubMed

T cell non-Hodgkin lymphoma is characterized by uncontrolled cellular proliferation of immature malignant clones. HIV-associated T cell non-Hodgkin lymphoma comprises a heterogeneous group of lymphoproliferative neoplastic entities classified according to morphological, immunological, genetic and clinical features. Extranodal T cell non-Hodgkin lymphoma of the oral cavity is uncommon. A case is presented with extranodal T cell non-Hodgkin lymphoma as an initial sign of HIV-infection. The characteristics of HIV-associated non-Hodgkin lymphoma are discussed. PMID:18689348

Wood, Neil H; Feller, Liviu; Raubenheimer, Erich J; Jadwat, Yusuf; Meyerov, Robin; Lemmer, Johan

2008-04-01

82

Ultrastructural alterations produced by sertaconazole on several opportunistic pathogenic fungi.  

PubMed

Sertaconazole is a new synthetic antifungal which has shown promising activity against numerous fungi. The morphological changes induced by the drug at two concentrations, the MIC and 10 times the MIC, during 24 and 48 h on the filamentous opportunistic fungi Aspergillus fumigatus, Chaetomium atrobrunneum and Scedosporium prolificans indicated that the intensity of the ultrastructural breakdown depended on the dose and not on the time of exposure. Common severe alterations of many fungal cells, which could be considered beyond repair, were seen at the cell wall, plasmalemma and cytoplasm levels. The results obtained underline the drug efficacy for those fungi and suggest its applicability as therapeutic agent in the human infections produced by them. PMID:8683408

Figueras, M J; Cano, J F; Guarro, J

1995-01-01

83

The impact of HIV-associated lipodystrophy on healthcare utilization and costs  

PubMed Central

Background HIV disease itself is associated with increased healthcare utilization and healthcare expenditures. HIV-infected persons with lipodystrophy have been shown to have poor self-perceptions of health. We evaluated whether lipodystrophy in the HIV-infected population was associated with increased utilization of healthcare services and increased healthcare costs. Objective To examine utilization of healthcare services and associated costs with respect to presence of lipodystrophy among HIV-infected patients. Methods Healthcare utilization and cost of healthcare services were collected from computerized accounting records for participants in a body image study among HIV-infected patients treated at a tertiary care medical center. Lipodystrophy was assessed by physical examination, and effects of lipodystrophy were assessed via body image surveys. Demographic and clinical characteristics were also ascertained. Analysis of healthcare utilization and cost outcomes was performed via between-group analyses. Multivariate modeling was used to determine predictors of healthcare utilization and associated costs. Results Of the 181 HIV-infected participants evaluated in the study, 92 (51%) had clinical evidence of HIV-associated lipodystrophy according to physician examination. Total healthcare utilization, as measured by the number of medical center visits over the study period, was notably increased among HIV-infected subjects with lipodystrophy as compared to HIV-infected subjects without lipodystrophy. Similarly, total healthcare expenditures over the study period were $1,718 more for HIV-infected subjects with lipodystrophy than for HIV-infected subjects without lipodystrophy. Multivariate modeling demonstrated strong associations between healthcare utilization and associated costs, and lipodystrophy score as assessed by a clinician. Healthcare utilization and associated costs were not related to body image survey scores among HIV-infected patients with lipodystrophy. Conclusion Patients with HIV-associated lipodystrophy demonstrate an increased utilization of healthcare services with associated increased healthcare costs as compared to HIV-infected patients without lipodystrophy. The economic and healthcare service burdens of HIV-associated lipodystrophy are significant and yet remain inadequately addressed by the medical community. PMID:18593479

Huang, Jeannie S; Becerra, Karen; Fernandez, Susan; Lee, Daniel; Mathews, WC

2008-01-01

84

Genetic shift of env V3 loop viral sequences in patients with HIV-associated neurocognitive disorder during antiretroviral therapy.  

PubMed

The development of human immunodeficiency virus type 1 (HIV)-associated neurocognitive disorder (HAND) involves the adaptation of viral sequences coding for the V3 loop of the env protein. The plasma and cerebrospinal fluid (CSF) may contain viral populations from various cellular sources and with differing pathogenicity. Combination antiretroviral therapy (cART) may alter the relative abundance of these viral populations, leading to a genetic shift. We characterized plasma and CNS viral populations prior to and during cART and relate the findings to viral elimination kinetics and the clinical phenotype. Longitudinal plasma and CSF samples of five chronically infected HIV patients, four of whom had HAND, and one seroconverter were analyzed for V3 sequences by RT-PCR and sequence analysis. In the chronically infected patients, pre-cART plasma and CSF viral sequences were different irrespective of viral elimination kinetics and clinical phenotype. cART induced replacement of plasma viral populations in all subjects. CSF viral populations underwent a clear genetic shift in some patients but remained stable in others. This was not dependent on the presence of HAND. The genetic shift of CSF V3 sequences was absent in the two subjects whose CSF viral load initially increased during cART. In one patient, pre- and post-treatment CSF sequences were closely related to the post-treatment plasma sequences, suggesting a common cellular source. We found heterogeneous patterns of genetic compartmentalization and genetic shift over time. Although these did not closely match viral elimination kinetics and clinical phenotype, the results imply different patterns of the dynamics and relative contribution of compartment-specific virus populations in chronic HIV infection. PMID:24101298

Eggers, Christian; Müller, Oliver; Thordsen, Ingo; Schreiber, Michael; Methner, Axel

2013-12-01

85

HIV-associated neurocognitive disorders before and during the era of combination antiretroviral therapy: differences in rates, nature, and predictors  

PubMed Central

Combination antiretroviral therapy (CART) has greatly reduced medical morbidity and mortality with HIV infection, but high rates of HIV-associated neurocognitive disorders (HAND) continue to be reported. Because large HIV-infected (HIV+) and uninfected (HIV?) groups have not been studied with similar methods in the pre-CART and CART eras, it is unclear whether CART has changed the prevalence, nature, and clinical correlates of HAND. We used comparable methods of subject screening and assessments to classify neurocognitive impairment (NCI) in large groups of HIV + and HIV ? participants from the pre-CART era (1988–1995; N?=?857) and CART era (2000–2007; N?=?937). Impairment rate increased with successive disease stages (CDC stages A, B, and C) in both eras: 25%, 42%, and 52% in pre-CART era and 36%, 40%, and 45% in CART era. In the medically asymptomatic stage (CDC-A), NCI was significantly more common in the CART era. Low nadir CD4 predicted NCI in both eras, whereas degree of current immunosuppression, estimated duration of infection, and viral suppression in CSF (on treatment) were related to impairment only pre-CART. Pattern of NCI also differed: pre-CART had more impairment in motor skills, cognitive speed, and verbal fluency, whereas CART era involved more memory (learning) and executive function impairment. High rates of mild NCI persist at all stages of HIV infection, despite improved viral suppression and immune reconstitution with CART. The consistent association of NCI with nadir CD4 across eras suggests that earlier treatment to prevent severe immunosuppression may also help prevent HAND. Clinical trials targeting HAND prevention should specifically examine timing of ART initiation. PMID:21174240

Franklin, Donald R.; Ellis, Ronald J.; McCutchan, J. Allen; Letendre, Scott L.; LeBlanc, Shannon; Corkran, Stephanie H.; Duarte, Nichole A.; Clifford, David B.; Woods, Steven P.; Collier, Ann C.; Marra, Christina M.; Morgello, Susan; Mindt, Monica Rivera; Taylor, Michael J.; Marcotte, Thomas D.; Atkinson, J. Hampton; Wolfson, Tanya; Gelman, Benjamin B.; McArthur, Justin C.; Simpson, David M.; Abramson, Ian; Gamst, Anthony; Fennema-Notestine, Christine; Jernigan, Terry L.; Wong, Joseph; Grant, Igor

2010-01-01

86

Computed tomography in opportunistic lung infections.  

PubMed

Chest radiography in two teenage boys, one with Wiscott-Aldrich's syndrome and one with acute lymphatic leucemia in remission showed increased interstitial pattern. In both computed tomography (CT) of the lungs showed heavy interstitial pneumonia, rather different in appearance but in both cases equal to the CT findings in opportunistic lung infections known from immunoincompetent patients with for instance pneumocystis carinii and/or cytomegalo virus infections. In both patients the CT findings led to lung biopsy establishing the etiologic agent. PMID:2833918

Hartelius, H

1988-01-01

87

Leptin and Adiponectin in the HIV Associated Metabolic Syndrome: Physiologic and Therapeutic Implications  

PubMed Central

Leptin and adiponectin represent two newly discovered adipose tissue derived hormones with important roles in energy homeostasis and insulin resistance. Their interrelations with the manifestations of the HIV associated metabolic syndrome and specific somatomorphic changes i.e. fat redistribution is reviewed. A synopsis of published studies is presented and the potential role of leptin and adiponectin is discussed. We have described an association of the HIV metabolic syndrome with a state of reduced insulin sensitivity due to adiponectin deficiency. The metabolic syndrome is also accompanied by leptin deficiency in lipoatrophic subjects and possibly by a leptin resistance state in lipohypertrophic patients. Adiponectin and / or leptin therapy in a manner similar to other leptin deficiency states may assist in the future management of such patients. PMID:17183414

Tsiodras, Sotirios; Mantzoros, Christos

2006-01-01

88

HIV-associated thrombocytopenia: in vitro megakaryocyte colony formation in 10 patients.  

PubMed

In vitro bone-marrow megakaryocyte colony formation was studied in 10 patients with HIV-associated thrombocytopenia to investigate the mechanism of thrombocytopenia. Increased colony formation was observed in 3 patients and decreased growth in 7 patients. No relationship was noted between the growth potential of megakaryocyte progenitors and platelet count, number of CD4+ celts, platelet response to azidothymidine, and platelet count 7 days after culture. In all patients, megakaryocyte morphology was abnormal: blebbing of the membrane and abnormal chromatin with separated lobes of nuclei. Further studies are needed to determine if growth potential of megakaryocyte progenitors is useful in understanding the mechanism of thrombocytopenia in HIV-infected individuals. PMID:1530216

Abgrall, J F; el Kassar, N; Berthou, C; Cauvin, J M; Renard, I; Autrand, C; Zilliken, P; Sensebe, L; Guern, G; Le Gall, G

1992-01-01

89

Developing neuroprotective strategies for treatment of HIV-associated neurocognitive dysfunction  

PubMed Central

Important advances have been made in recent years in identifying the molecular mechanisms of HIV neuropathogenesis. Defining the pathways leading to HIV dementia has created an opportunity to therapeutically target many steps in the pathogenic process. HIV itself rarely infects neurons, but significant neuronal damage is caused both by viral proteins and by inflammatory mediators produced by the host in response to infection. Highly active antiretroviral therapy (HAART) does not target these mediators of neuronal damage, and the prevalence of HIV-associated neurocognitive dysfunction has actually been rising in the post-HAART era. This review will briefly summarize our current understanding of the mechanisms of HIV-induced neurological disease, and emphasize translation of this basic research into potential clinical applications. PMID:19774095

Rumbaugh, Jeffrey A; Steiner, Joseph; Sacktor, Ned; Nath, Avindra

2009-01-01

90

Reconfigurable cognitive transceiver for opportunistic networks  

NASA Astrophysics Data System (ADS)

In this work, we provide the implementation and analysis of a cognitive transceiver for opportunistic networks. We focus on a previously introduced dynamic spectrum access (DSA) - cognitive radio (CR) solution for primary-secondary coexistence in opportunistic orthogonal frequency division multiplexing (OFDM) networks, called cognitive interference alignment (CIA). The implementation is based on software-defined radio (SDR) and uses GNU Radio and the universal software radio peripheral (USRP) as the implementation toolkit. The proposed flexible transceiver architecture allows efficient on-the-fly reconfigurations of the physical layer into OFDM, CIA or a combination of both. Remarkably, its responsiveness is such that the uplink and downlink channel reciprocity from the medium perspective, inherent to time division duplex (TDD) communications, can be effectively verified and exploited. We show that CIA provides approximately 10 dB of interference isolation towards the OFDM receiver with respect to a fully random precoder. This result is obtained under suboptimal conditions, which indicates that further gains are possible with a better optimization of the system. Our findings point towards the usefulness of a practical CIA implementation, as it yields a non-negligible performance for the secondary system, while providing interference shielding to the primary receiver.

Maso, Marco; Ba?tu?, Ejder; Cardoso, Leonardo S.; Debbah, Mérouane; Özdemir, Özgür

2014-12-01

91

Current laboratory diagnosis of opportunistic enteric parasites in human immunodeficiency virus-infected patients  

PubMed Central

Diarrhea is a major cause of morbidity and mortality in human immunodeficiency virus (HIV)-infected individuals. Opportunistic enteric parasitic infections are encountered in 30-60% of HIV seropositive patients in developed countries and in 90% of patients in developing countries. Once the CD4+ cell count drops below 200 cells/?l, patients are considered to have developed acquired immunodeficiency syndrome (AIDS), with the risk of an AIDS-defining illness or opportunistic infection significantly increasing. Opportunistic enteric parasites encountered in these patients are Cryptosporidium, Isospora, Cyclospora, and microsporidia; as well as those more commonly associated with gastrointestinal disease, for example, Giardia intestinalis, Entamoeba histolytica, Strongyloides stercoralis, and also rarely Balantidium coli. In view of AIDS explosion in India, opportunistic enteric parasites are becoming increasingly important and it has to be identified properly. Apart from wet mounts, concentration methods for stool samples and special staining techniques for identification of these parasites, commercially available fecal immunoassays are widely available for the majority of enteric protozoa. Molecular methods such as polymerase chain reaction (PCR), PCR-restriction fragment length polymorphism, flow cytometry, and sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), have also come in the pipeline for early diagnosis of these infections. Proper disposal of the feces to prevent contamination of the soil and water, boiling/filtering drinking water along with improved personal hygiene might go a long way in preventing these enteric parasitic infections. PMID:23961436

De, Anuradha

2013-01-01

92

An opportunistic platform for Android-based mobile devices  

Microsoft Academic Search

This paper describes a novel Android-based opportunistic platform for mobile computing applications. It has the aim to incentive the growth of practical experiences that should give an answer to the following question: can Opportunistic Networks actually compete with cellular networks to support urban-wide mobile computing applications?

Paolo Meroni; Elena Pagani; Gian Paolo Rossi; Lorenzo Valerio

2010-01-01

93

Epidemic Diffusion of Data in Opportunistic Netw orks  

E-print Network

Epidemic Diffusion of Data in Opportunistic Netw orks Francesco Giudici, Elena Pagani, Gian Paolo Comunicazione #12;Epidemic diffusion of data in opportunistic networks Francesco Giudici, Elena Pagani, Gian focuses on this argument and proposes the use of epidemic algorithms to provide best effort data delivery

Pagani, Elena

94

A framework for opportunistic scheduling in wireless networks  

Microsoft Academic Search

We present a method, called opportunistic scheduling, for exploiting the time- varying nature of the radio environment to increase the overall performance of the system under certain QoS\\/fairness requirements of users. We flrst introduce a general framework for opportunistic scheduling, and then identify three general categories of scheduling problems under this framework. We provide optimal solu- tions for each of

Xin Liu; Edwin K. P. Chong; Ness B. Shroff

2003-01-01

95

Opportunistic programming: how rapid ideation and prototyping occur in practice  

Microsoft Academic Search

At times, programmers work opportunistically, emphasizing speed and ease of development over code robustness and maintainability. They do this to prototype, ideate, and discover; to understand as quickly as possible what the right solution is. Despite its importance, opportunistic programming remains poorly understood when compared with traditional software engineering. Through fieldwork and a laboratory study, we observed five characteristics of

Joel Brandt; Philip J. Guo; Joel Lewenstein; Scott R. Klemmer

2008-01-01

96

Trading structure for randomness in wireless opportunistic routing  

Microsoft Academic Search

Opportunistic routing is a recent technique that achieves high throughput in the face of lossy wireless links. The current oppor- tunistic routing protocol, ExOR, ties the MAC with routing, impos- ing a strict schedule on routers' access to the medium. Although the scheduler delivers opportunistic gains, it misses some of the inherent features of the 802.11 MAC. For example, it

Szymon Chachulski; Michael Jennings; Sachin Katti; Dina Katabi

2007-01-01

97

Directional navigation improves opportunistic communication for emergencies.  

PubMed

We present a novel direction based shortest path search algorithm to guide evacuees during an emergency. It uses opportunistic communications (oppcomms) with low-cost wearable mobile nodes that can exchange packets at close range of a few to some tens of meters without help of an infrastructure. The algorithm seeks the shortest path to exits which are safest with regard to a hazard, and is integrated into an autonomous Emergency Support System (ESS) to guide evacuees in a built environment. The algorithm proposed that ESSs are evaluated with the DBES (Distributed Building Evacuation Simulator) by simulating a shopping centre where fire is spreading. The results show that the directional path finding algorithm can offer significant improvements for the evacuees. PMID:25140633

Kokuti, Andras; Gelenbe, Erol

2014-01-01

98

Directional Navigation Improves Opportunistic Communication for Emergencies  

PubMed Central

We present a novel direction based shortest path search algorithm to guide evacuees during an emergency. It uses opportunistic communications (oppcomms) with low-cost wearable mobile nodes that can exchange packets at close range of a few to some tens of meters without help of an infrastructure. The algorithm seeks the shortest path to exits which are safest with regard to a hazard, and is integrated into an autonomous Emergency Support System (ESS) to guide evacuees in a built environment. The algorithm proposed that ESSs are evaluated with the DBES (Distributed Building Evacuation Simulator) by simulating a shopping centre where fire is spreading. The results show that the directional path finding algorithm can offer significant improvements for the evacuees. PMID:25140633

Kokuti, Andras.; Gelenbe, Erol.

2014-01-01

99

HIV-associated wasting in the HAART era: guidelines for assessment, diagnosis, and treatment.  

PubMed

Wasting (malnutrition) and lipodystrophy are the two major nutritional alterations in human immunodeficiency virus (HIV)-infected individuals. Both wasting and lipodystrophy may involve a decrease in body fat content, while wasting-but not lipodystrophy-also includes the loss of lean body mass. Lipodystrophy has made the identification of wasting increasingly more difficult. The diagnosis of wasting depends on a definition of the condition that takes into account sex and cultural differences, as well as measurements of body cell mass. Patient management involves a concurrent, comprehensive approach designed to restore lost body cell mass and weight. The authors make recommendations for defining, diagnosing, and treating HIV-associated wasting. Specific therapies include testosterone replacement, other anabolic steroids, and recombinant human growth hormone. Other adjunctive measures, such as progressive resistance exercise and cytokine modulation, may also be utilized. Expected outcomes from effective treatment include restored body cell mass, improvement in quality of life, and reduced rates of hospitalization. Future directions for research should address the need for optimal treatment strategies. PMID:11522215

Polsky, B; Kotler, D; Steinhart, C

2001-08-01

100

APOL1 Genetic Variants in Focal Segmental Glomerulosclerosis and HIV-Associated Nephropathy  

PubMed Central

Trypanolytic variants in APOL1, which encodes apolipoprotein L1, associate with kidney disease in African Americans, but whether APOL1-associated glomerular disease has a distinct clinical phenotype is unknown. Here we determined APOL1 genotypes for 271 African American cases, 168 European American cases, and 939 control subjects. In a recessive model, APOL1 variants conferred seventeenfold higher odds (95% CI 11 to 26) for focal segmental glomerulosclerosis (FSGS) and twenty-nine-fold higher odds (95% CI 13 to 68) for HIV-associated nephropathy (HIVAN). FSGS associated with two APOL1 risk alleles associated with earlier age of onset (P = 0.01) and faster progression to ESRD (P < 0.01) but similar sensitivity to steroids compared with other subjects. Individuals with two APOL1 risk alleles have an estimated 4% lifetime risk for developing FSGS, and untreated HIV-infected individuals have a 50% risk for developing HIVAN. The effect of carrying two APOL1 risk alleles explains 18% of FSGS and 35% of HIVAN; alternatively, eliminating this effect would reduce FSGS and HIVAN by 67%. A survey of world populations indicated that the APOL1 kidney risk alleles are present only on African chromosomes. In summary, African Americans carrying two APOL1 risk alleles have a greatly increased risk for glomerular disease, and APOL1-associated FSGS occurs earlier and progresses to ESRD more rapidly. These data add to the evidence base required to determine whether genetic testing for APOL1 has a use in clinical practice. PMID:21997394

Nelson, George W.; Sampath, Karmini; Johnson, Randall C.; Genovese, Giulio; An, Ping; Friedman, David; Briggs, William; Dart, Richard; Korbet, Stephen; Mokrzycki, Michele H.; Kimmel, Paul L.; Limou, Sophie; Ahuja, Tejinder S.; Berns, Jeffrey S.; Fryc, Justyna; Simon, Eric E.; Smith, Michael C.; Trachtman, Howard; Michel, Donna M.; Schelling, Jeffrey R.; Vlahov, David; Pollak, Martin; Winkler, Cheryl A.

2011-01-01

101

Lower Cognitive Reserve Among Individuals with Syndromic HIV-associated Neurocognitive Disorders (HAND)  

PubMed Central

HIV-seropositive individuals with low cognitive reserve are at high risk for developing HIV-associated neurocognitive disorders (HAND). The present study evaluated the hypothesis that cognitive reserve would also play a unique role in the expression of everyday functioning complications among those with HAND (i.e., syndromic versus subsyndromic impairment). Eighty-six individuals with HIV infection were evaluated; 53 individuals evidenced normal neurocognitive performance, 16 had subsyndromic HAND (i.e., Asymptomatic Neurocognitive Impairment), and 17 were diagnosed with a syndromic HAND based on a comprehensive neurobehavioral evaluation. Cognitive reserve represented a combined score including years of education, estimated verbal IQ, and highest occupational attainment. The groups were comparable (e.g. demographics), and the HAND groups had similar rates of global neurocognitive impairment. The Syndromic HAND group evidenced lower reserve scores relative to both other groups, suggesting that HIV-infected individuals with high cognitive reserve more effectively counteract their neurocognitive impairment to maintain independence in daily living activities. PMID:22677976

Morgan, Erin E.; Woods, Steven Paul; Smith, Christine; Weber, Erica; Scott, J. Cobb; Grant, Igor

2012-01-01

102

Epidemiology of HIV-associated tuberculosis Running Head: Epidemiology of TB /HIV  

PubMed Central

Purpose of review We review literature concerning the epidemiology of HIV-associated tuberculosis (HIV-TB), focussing on articles published between 2007-2008. Recent findings An estimated 1.37 million new cases of HIV-TB occurred in 2007, representing 15% of the total global burden of TB. In addition, an estimated 456,000 HIV-TB deaths accounted for 23% of global HIV/AIDS mortality. Sub-Saharan Africa is the worst affected region with 79% of the disease burden. The epicentre of the co-epidemic lies in the south of the continent, with South Africa alone accounting for over one quarter of all cases. A critical overlap between HIV and the global multi-drug resistant TB (MDR-TB) epidemics is emerging. Although it is as yet unclear whether HIV is driving a disproportionate increase in MDR-TB cases at a population level, HIV has nevertheless been a potent risk factor for institutional outbreaks, especially in South Africa and Eastern Europe. Increasing data have highlighted the risk of TB among HIV-infected health-care workers in resource-limited settings. However, many studies also show the major benefits to be derived from antiretroviral therapy in high- and low-income countries. Summary HIV-TB remains a major challenge to global health that requires substantial increases in resource allocation and concerted international action. PMID:19532072

Lawn, Stephen D.; Churchyard, Gavin

2014-01-01

103

Antibodies against Mycobacterial proteins as biomarkers for HIV-associated smear-negative tuberculosis.  

PubMed

Serology data are limited for patients with sputum smear-negative HIV-associated active tuberculosis (TB). We evaluated the serum antibody responses against the mycobacterial proteins MPT51, MS, and echA1 and the 38-kDa protein via enzyme-linked immunosorbent assay (ELISA) in South African (S.A.) HIV-positive (HIV(+)) smear-negative TB patients (n = 56), U.S. HIV(+) controls with a positive tuberculin skin test (TST(+); n = 21), and S.A. HIV-negative (HIV(-)) (n = 18) and HIV(+) (n = 24) controls. TB patients had positive antibody reactivity against MPT51 (73%), echA1 (59%), MS (36%), and the 38-kDa protein (11%). Little reactivity against MPT51 and echA1 was observed in control groups at low risk for TB, i.e., S.A. HIV(-) (0% and 6%, respectively), and at moderate risk for TB development, i.e., U.S. HIV(+) TST(+) controls (14% and 10%, respectively). By contrast, more reactivity was detected in the S.A. HIV(+) control group at higher risk for TB (25% and 45%, respectively). Our data hold promise that antibody detection against MPT51 and echA1 might have adjunctive value in the detection of HIV(+) smear-negative TB and might reflect increasing Mycobacterium tuberculosis infection activity in asymptomatic HIV(+) individuals. PMID:24671553

Siev, Michael; Wilson, Douglas; Kainth, Supreet; Kasprowicz, Victoria O; Feintuch, Catherine M; Jenny-Avital, Elizabeth R; Achkar, Jacqueline M

2014-06-01

104

The evolution of our knowledge of HIV-associated kidney disease in Africa.  

PubMed

Human immunodeficiency virus (HIV) infection started in Africa circa 1930. South Africa has the highest prevalence rate in the world. Although reports of HIV-associated nephropathy (HIVAN) appeared in the early 1980s, the earliest report from sub-Saharan Africa (SSA) came in 1994. Geographical, socioeconomic, political, and ethical factors have worked in concert to shape the character of HIV disease as it is seen in SSA. Political leaders within SSA have, through their actions, significantly contributed to the incidence of HIV infection. Black females, who often face cultural suppression and disadvantage, have a higher prevalence of HIV than males. Too few studies and outcomes data have bedeviled the statistics in SSA in relation to HIVAN prevalence and its management. Much of what is written is approximation and anecdotal. The largest reliable biopsy series comes from the University of Cape Town, where a workable classification of HIVAN has been developed to enable standardization of terminology. Histologic and clinical prognostic indicators with outcomes have been evaluated using this classification. Patients with HIV who present with acute kidney injury appear to have mainly acute tubular necrosis due to sepsis, dehydration, and nephrotoxic drugs. Since the rollout of combination antiretroviral therapy, the extent of HIV infection and kidney disease continues to be modified and possibly retarded. PMID:22901595

Swanepoel, Charles R; Wearne, Nicola; Duffield, Maureen S; Okpechi, Ikechi G

2012-10-01

105

Challenges in Evaluating the Cost-effectiveness of New Diagnostic Tests for HIV-Associated Tuberculosis  

PubMed Central

With an emerging array of rapid diagnostic tests for tuberculosis, cost-effectiveness analyses are needed to inform scale-up in various populations and settings. Human immunodeficiency virus (HIV)–associated tuberculosis poses unique challenges in estimating and interpreting the cost-effectiveness of novel diagnostic tools. First, gains in sensitivity and specificity do not directly correlate with impact on clinical outcomes. Second, the cost-effectiveness of implementing tuberculosis diagnostics in HIV-infected populations is heavily influenced by downstream costs of HIV care. As a result, tuberculosis diagnostics may appear less cost-effective in this population than among HIV-uninfected individuals, raising important ethical and policy questions about the design and interpretation of cost-effectiveness analyses in this setting. Third, conventional cost-effectiveness benchmarks may be inadequate for making decisions about whether to adopt new diagnostics. If we are to appropriately deploy novel diagnostics for tuberculosis to people living with HIV in resource-constrained settings, these challenges in measuring cost-effectiveness must be more widely recognized and addressed. PMID:23788239

Andrews, Jason R.; Lawn, Stephen D.; Dowdy, David W.; Walensky, Rochelle P.

2013-01-01

106

Neuronal ferritin heavy chain and drug abuse affect HIV-associated cognitive dysfunction  

PubMed Central

Interaction of the chemokine CXCL12 with its receptor CXCR4 promotes neuronal function and survival during embryonic development and throughout adulthood. Previous studies indicated that ?-opioid agonists specifically elevate neuronal levels of the protein ferritin heavy chain (FHC), which negatively regulates CXCR4 signaling and affects the neuroprotective function of the CXCL12/CXCR4 axis. Here, we determined that CXCL12/CXCR4 activity increased dendritic spine density, and also examined FHC expression and CXCR4 status in opiate abusers and patients with HIV-associated neurocognitive disorders (HAND), which is typically exacerbated by illicit drug use. Drug abusers and HIV patients with HAND had increased levels of FHC, which correlated with reduced CXCR4 activation, within cortical neurons. We confirmed these findings in a nonhuman primate model of SIV infection with morphine administration. Transfection of a CXCR4-expressing human cell line with an iron-deficient FHC mutant confirmed that increased FHC expression deregulated CXCR4 signaling and that this function of FHC was independent of iron binding. Furthermore, examination of morphine-treated rodents and isolated neurons expressing FHC shRNA revealed that FHC contributed to morphine-induced dendritic spine loss. Together, these data implicate FHC-dependent deregulation of CXCL12/CXCR4 as a contributing factor to cognitive dysfunction in neuroAIDS. PMID:24401274

Pitcher, Jonathan; Abt, Anna; Myers, Jaclyn; Han, Rachel; Snyder, Melissa; Graziano, Alessandro; Festa, Lindsay; Kutzler, Michele; Garcia, Fernando; Gao, Wen-Jun; Fischer-Smith, Tracy; Rappaport, Jay; Meucci, Olimpia

2014-01-01

107

Opportunistic infections due to inflammatory bowel disease therapy.  

PubMed

The use of biological agents and immunomodulators for inflammatory bowel disease (IBD) has remarkably improved disease management in the current era but at the same time has increased the risk of infectious complications. Patients with IBD on corticosteroids, immunomodulators, and biological agents are considered immunocompromised and are at risk for opportunistic infections. These are infections caused by organisms that take advantage of a weakened immune system, and cause disease, when they ordinarily would cause mild illness or no disease in an immunocompetent host. Risk factors for opportunistic infections include malnutrition, older age, congenital immunodeficiency, HIV infection, chronic diseases, and use of corticosteroids, immunomodulators, and anti-tumor necrosis factor alpha therapy. Apart from immunosuppressive medications and older age, there is only indirect evidence for above risk factors contributing directly to opportunistic infection risk in patients with IBD. Opportunistic infections in patients with IBD include viral infections (herpes viruses, human papillomavirus, influenza virus, and JC virus), bacterial infections (tuberculosis, nocardiosis, Clostridium difficile infection, pneumococcal infection, legionellosis, and listeriosis), fungal infections (histoplasmosis, cryptococcosis, Pneumocystis jirovecii infection, aspergillosis, and candidiasis), and parasite infections (Strongyloides stercoralis). Although these infections lead to high morbidity and mortality, only a minority of patients with IBD develop opportunistic infections. Currently, we lack a test to accurately predict patients at risk of opportunistic infection, and future research needs to focus on biomarkers or predictive models for risk stratification. Until such a test is developed, we need to screen, prevent, diagnose, and treat opportunistic infections in all patients with IBD in a timely manner. PMID:24051931

Dave, Maneesh; Purohit, Treta; Razonable, Raymund; Loftus, Edward V

2014-01-01

108

Therapy of HIV-associated lymphoma-recommendations of the oncology working group of the German Study Group of Physicians in Private Practice Treating HIV-Infected Patients (DAGNÄ), in cooperation with the German AIDS Society (DAIG).  

PubMed

AIDS-related aggressive B cell lymphoma (HIV-NHL) is the second most common HIV-associated malignancy. In contrast, Hodgkin-lymphoma (HL) is one of the most common non-AIDS-defining malignancies. Current evidence-based recommendations for the treatment of HIV-associated lymphoma (HIV-lymphoma) are not available. A panel of experts in the field of HIV-related lymphoma performed literature searches of the PubMed, Medline, and Cochrane databases. The consensus process was carried out as an e-mail and meeting-based discussion group. Six cycles of R-CHOP or R-EPOCH are standard of care for patients (pts) with diffuse large B cell lymphoma (DLBCL). Pts with Burkitt lymphoma and good performance status should receive dose-intensive regimens such as the GMALL B-ALL/NHL protocol. Standard therapy has not been defined for pts with plasmablastic and primary effusion lymphoma. Pts with lymphoma in sensitive relapse should receive high-dose chemotherapy followed by autologous stem cell transplantation. Stage- and risk adapted treatment yields high remission and survival rates in pts with HIV-HL similar to those achieved in HIV-negative HL pts. Combination antiretroviral therapy (cART) should be applied concurrently to chemotherapy provided that pharmacokinetic interactions are being considered. Pts with HIV-lymphoma should usually be treated in an identical manner to HIV-negative patients. PMID:24807241

Hentrich, Marcus; Hoffmann, Christian; Mosthaf, Franz; Müller, Markus; Siehl, Jan; Wyen, Christoph; Hensel, Manfred

2014-06-01

109

The role of protease inhibitors in the pathogenesis of HIV-associated insulin resistance: Cellular mechanisms and clinical implications  

Microsoft Academic Search

HIV-associated insulin resistance frequently presents as relative lack of peripheral adipose tissue storage associated with\\u000a dyslipidemia. This review discusses explanations for the links between acute and subacute abnormalities in glucose metabolism\\u000a and chronic changes in adipose tissue distribution. Specifically, the molecular mechanisms by which the HIV protease inhibitor\\u000a class of drugs may affect the normal stimulatory effect of insulin on

Mustafa A. Noor

2007-01-01

110

Update on opportunistic infections in the era of effective antiretroviral therapy.  

PubMed

Despite enormous improvements in effectiveness of treatment for HIV infection, opportunistic infections continue to occur in those who have not yet been diagnosed with HIV and in those who are not receiving antiretroviral therapy. This review focuses on tuberculosis and cryptococcal infections, the most common opportunistic infections (OIs) in patients living with human immunodeficiency virus infection around the world, as well as on new developments in progressive multifocal leukoencephalopathy and pneumocystis pneumonia. In the sections on these conditions, updates on diagnosis, treatment, and complications, as well as information on when to start antiretroviral therapy is provided. The article concludes with a discussion of new data on 2 vaccine-preventable OIs, human papillomavirus and varicella-zoster virus. PMID:25151568

Zanoni, Brian C; Gandhi, Rajesh T

2014-09-01

111

Opportunistic invasive fungal infections: diagnosis & clinical management.  

PubMed

Invasive fungal infections are a significant health problem in immunocompromised patients. The clinical manifestations vary and can range from colonization in allergic bronchopulmonary disease to active infection in local aetiologic agents. Many factors influence the virulence and pathogenic capacity of the microorganisms, such as enzymes including extracellular phospholipases, lipases and proteinases, dimorphic growth in some Candida species, melanin production, mannitol secretion, superoxide dismutase, rapid growth and affinity to the blood stream, heat tolerance and toxin production. Infection is confirmed when histopathologic examination with special stains demonstrates fungal tissue involvement or when the aetiologic agent is isolated from sterile clinical specimens by culture. Both acquired and congenital immunodeficiency may be associated with increased susceptibility to systemic infections. Fungal infection is difficult to treat because antifungal therapy for Candida infections is still controversial and based on clinical grounds, and for molds, the clinician must assume that the species isolated from the culture medium is the pathogen. Timely initiation of antifungal treatment is a critical component affecting the outcome. Disseminated infection requires the use of systemic agents with or without surgical debridement, and in some cases immunotherapy is also advisable. Preclinical and clinical studies have shown an association between drug dose and treatment outcome. Drug dose monitoring is necessary to ensure that therapeutic levels are achieved for optimal clinical efficacy. The objectives of this review are to discuss opportunistic fungal infections, diagnostic methods and the management of these infections. PMID:24718393

Badiee, Parisa; Hashemizadeh, Zahra

2014-02-01

112

MOTIVATION MAIN IDEA An Opportunistic Data Backup System for MANETs  

E-print Network

MOTIVATION MAIN IDEA An Opportunistic Data Backup System for MANETs Roy Friedman, David Sainz Aline is very scarce · This reality motivates the need for ad- hoc cloud services · Mobile cloud storage service

Chaudhuri, Surajit

113

On investigating social dynamics in tactical opportunistic mobile networks  

NASA Astrophysics Data System (ADS)

The efficiency of military mobile network operations at the tactical edge is challenging due to the practical Disconnected, Intermittent, and Limited (DIL) environments at the tactical edge which make it hard to maintain persistent end-to-end wireless network connectivity. Opportunistic mobile networks are hence devised to depict such tactical networking scenarios. Social relations among warfighters in tactical opportunistic mobile networks are implicitly represented by their opportunistic contacts via short-range radios, but were inappropriately considered as stationary over time by the conventional wisdom. In this paper, we develop analytical models to probabilistically investigate the temporal dynamics of this social relationship, which is critical to efficient mobile communication in the battlespace. We propose to formulate such dynamics by developing various sociological metrics, including centrality and community, with respect to the opportunistic mobile network contexts. These metrics investigate social dynamics based on the experimentally validated skewness of users' transient contact distributions over time.

Gao, Wei; Li, Yong

2014-06-01

114

Neurovirological correlation with HIV-associated neurocognitive disorders and encephalitis in a HAART-era cohort  

PubMed Central

Objective Replicating HIV-1 in the brain is present in HIV encephalitis (HIVE) and microglial nodule encephalitis (MGNE) and is putatively linked with HIV-associated neurocognitive disorders (HAND). A clinico-neurovirological correlation was conducted to elucidate the relationship between brain viral load and clinical phenotype. Subjects and assays HIV gag/pol RNA and DNA copies were quantified with RT-PCR or PCR in 148 HAART-era brain specimens. Comparison to HAND, HIVE and MGNE and correlation with neuropsychological (NP) test scores were done using one-way ANOVA with Tukey-Kramer and Spearman’s tests respectively. Results Brain HIV RNA was higher in subjects with HAND plus HIVE vs without HAND (delta = 2.48 log10 units, n = 27 vs 36, p < 0.001). In HAND without HIVE or MGNE, brain HIV RNA was not significantly different vs without HAND (p = 0.314). Worse NP scores correlated significantly with higher HIV RNA and interferon responses in brain specimens (p<0.001), but not with HIV RNA levels in premortem blood plasma (n = 114) or cerebrospinal fluid (n = 104). In subjects with MGNE, brain HIV RNA was slightly higher versus without MGNE (p<0.01), and much lower versus with HIVE (p<0.001). Conclusion Brain HIV RNA and to a lesser extent HIV DNA are correlated with worse NP performance in the 6 months before death. Linkage occurs primarily in patients with HIVE and MGNE; while on HAART these patients could obtain added NP improvement by further reducing brain HIV. Patients not in those groups are less certain to obtain added NP benefit. PMID:23242157

Gelman, Benjamin B.; Lisinicchia, Joshua G.; Morgello, Susan; Masliah, Eliezer; Commins, Deborah; Achim, Cristian L.; Fox, Howard S.; Kolson, Dennis L.; Grant, Igor; Singer, Elyse; Yiannoutsos, Constantin T.; Sherman, Seth; Gensler, Gary; Moore, David J.; Chen, Tiansheng; Soukup, Vicki M.

2013-01-01

115

Identifying risk factors for HIV-associated neurocognitive disorders using the international HIV dementia scale.  

PubMed

HIV-associated neurocognitive disorders (HAND) persist despite great advancements in combination antiretroviral therapy (cART). The gold standard for diagnosing cognitive impairment consists of a time-consuming neuropsychological battery of tests given by a trained neuropsychologist, however in the outpatient HIV clinic this is not feasible. The International HIV Dementia Scale (IHDS) was developed to help identify individuals with cognitive impairment in the outpatient setting. The IHDS is moderately sensitive for detecting more symptomatic forms of HAND but sensitivity has been shown to be poor in mild impairment. The IHDS has not been evaluated in developed countries in large cohort populations. We conducted a prospective cross-sectional study of only HIV+ individuals in an urban clinic and evaluated the prevalence of HAND and associated risk factors for cognitive impairment using the IHDS. A total of 507 HIV+ individuals participated in the study of which the majority were male (65 %) and African American (68 %); and 41 % had cognitive impairment. On multivariate analysis, African American race (p?=?2.21), older age (p?=?1.03), high school education or less (p?=?2.03) and depression (p?=?1.05) were associated with cognitive impairment. The high prevalence of HAND in this group suggests that more severe forms of HAND persist despite cART. Identified risk factors were non-HIV-related and suggest that environmental and sociodemographic factors have a significant impact on cognitive functioning and should be given more attention. The IHDS should be further evaluated in large cohort HIV+ and HIV- populations in the United States, as there remains a significant need to identify an effective brief screening tool for cognitive impairment. PMID:24114509

Cross, Sara; Önen, Nur; Gase, Amber; Overton, Edgar Turner; Ances, Beau M

2013-12-01

116

Dual-mixed HIV-1 Coreceptor Tropism and HIV-Associated Neurocognitive Deficits  

PubMed Central

Background HIV coreceptor usage of CXCR4 (X4) is associated with decreased CD4+ T-cell counts and accelerated disease progression, but the role of X4 tropism in HIV-associated neurocognitive disorders (HAND) has not previously been described. Methods This longitudinal study evaluated data on 197 visits from 72 recently HIV-infected persons who had undergone up to 4 sequential neurocognitive assessments over a median of 160 days (IQR 138–192). Phenotypic tropism testing (Trofile ES, Monogram, Biosciences) was performed on stored blood samples. Multivariable mixed model repeated measures regression was used to determine the association between HAND and dual-mixed (DM) viral tropism, estimated duration of infection (EDI), HIV RNA, CD4 count and problematic methamphetamine use. Results Six subjects (8.3%) had dual mixed tropism (DM) at their first neurocognitive assessment and four converted to DM in subsequent sampling (for total of 10 DM) at a median EDI of 10.1 months (IQR 7.2–12.2). There were 44 (61.1%) subjects who demonstrated HAND on at least one study visit. HAND was associated with DM tropism (odds ratio 4.4, 95% CI 0.9–20.5) and shorter EDI (odds ratio 1.1 per month earlier, 95% CI 1.0–1.2). Conclusion This study found that recency of HIV-1 infection and the development of DM tropism may be associated with HAND in the relatively early stage of infection. Together these data suggest that viral interaction with cellular receptors may play an important role in the early manifestation of HAND. PMID:24078557

Morris, Sheldon R.; Woods, Steven Paul; Deutsch, Reena; Little, Susan J.; Wagner, Gabriel; Morgan, Erin E.; Heaton, Robert K.; Letendre, Scott L.; Grant, Igor; Smith, Davey M.

2014-01-01

117

The looming epidemic of diabetes-associated tuberculosis: learning lessons from HIV-associated tuberculosis.  

PubMed

The prevalence of diabetes mellitus is increasing at a dramatic rate, and countries in Asia, particularly India and China, will bear the brunt of this epidemic. Persons with diabetes have a significantly increased risk of active tuberculosis (TB), which is two to three times higher than in persons without diabetes. In this article, we argue that the epidemiological interactions and the effects on clinical presentation and treatment resulting from the interaction between diabetes and TB are similar to those observed for human immunodeficiency virus (HIV) and TB. The lessons learned from approaches to reduce the dual burden of HIV and TB, and especially the modes of screening for the two diseases, can be adapted and applied to the screening, diagnosis, treatment and prevention of diabetes and TB. The new World Health Organization (WHO) and The Union Collaborative Framework for care and control of TB and diabetes has many similarities to the WHO Policy on Collaborative Activities to reduce the dual burden of TB and HIV, and aims to guide policy makers and implementers on how to move forward and combat this looming dual epidemic. The response to the growing HIV-associated TB epidemic in the 1980s and 1990s was slow and uncoordinated, despite clearly articulated warnings about the scale of the forthcoming problem. We must not make the same mistake with diabetes and TB. The Framework provides a template for action, and it is now up to donors, policy makers and implementers to apply the recommendations in the field and to 'learn by doing'. PMID:21902876

Harries, A D; Lin, Y; Satyanarayana, S; Lönnroth, K; Li, L; Wilson, N; Chauhan, L S; Zachariah, R; Baker, M A; Jeon, C Y; Murray, M B; Maher, D; Bygbjerg, I C; Enarson, D A; Billo, N E; Kapur, A

2011-11-01

118

Adjunctive Interferon-? Immunotherapy for the Treatment of HIV-associated Cryptococcal Meningitis: A Randomized Controlled Trial.  

PubMed Central

Background Interferon-? is of key importance in the immune response to Cryptococcus neoformans. Mortality related to cryptococcal meningitis (CM) remains high, and novel treatment strategies are needed. We performed an RCT to determine whether addition of IFN? to standard therapy increased the rate of clearance of cryptococcal infection in HIV-associated CM. Methods Patients were randomized to: (1) Amphotericin-B 1mg/kg/day plus 5-FC 100mg/kg/day for 2-weeks (Standard therapy), (2) Standard therapy plus IFN?1b 100?g days 1 and 3 (IFN? 2-doses), or (3) Standard therapy plus IFN?1b 100?g days 1, 3, 5, 8, 10 and 12 (IFN? 6-doses). Primary outcome was rate of clearance of cryptococcus from the CSF (early fungicidal activity, EFA) calculated from serial quantitative cultures, previously shown to be independently associated with survival. Results Rate of fungal clearance was significantly faster in IFN? containing groups than with standard treatment. Mean EFA (logCFU/ml/day) was ?0.49 with standard treatment, ?0.64 with IFN? 2-doses, and ?0.64 with IFN? 6-doses. Difference in EFA was ?0.15 (95%CI ?0.02- ?0.27, p=0.02) between standard treatment and IFN? 2-doses, and ?0.15 (95%CI-0.05- ?0.26, p=0.006) between standard treatment and IFN? 6-doses. Mortality was 16% (14/88) at 2 weeks and 31% (27/87) at 10 weeks, with no significant difference between groups. All treatments were well tolerated. Conclusions Addition of short-course IFN? to standard treatment significantly increased the rate of clearance of cryptococcal infection from the CSF, and was not associated with any increase in adverse events. Two doses of IFN? are as effective as 6 doses. PMID:22421244

Jarvis, Joseph N; Meintjes, Graeme; Rebe, Kevin; Williams, Gertrude Ntombomzi; Bicanic, Tihana; Williams, Anthony; Schutz, Charlotte; Bekker, Linda-Gail; Wood, Robin; Harrison, Thomas S

2013-01-01

119

The Role of Opportunistic Migration in Cyclic Games  

PubMed Central

We study cyclic evolutionary games in a spatial diluted grid environment in which agents strategically interact locally but can also opportunistically move to other positions within a given migration radius. We find that opportunistic migration can inverse the cyclic prevalence between the strategies when the frequency of random imitation is large enough compared to the payoff-driven imitation. At the transition the average size of the patterns diverges and this threatens diversity of strategies. PMID:24892660

Buesser, Pierre; Tomassini, Marco

2014-01-01

120

HIV-associated Prospective Memory Impairment in the Laboratory Predicts Failures on a Semi-naturalistic Measure of Health Care Compliance  

PubMed Central

HIV-associated neurocognitive impairment, particularly in the domain of prospective memory (ProM), increases the risk of poor everyday functioning outcomes, including medication non-adherence. However, whether ProM plays a role in health care compliance outside of the realm of medication adherence remains to be determined. This study evaluated the hypothesis that ProM is an independent predictor of failure to comply with non-medication related instructions akin to those commonly given by health care providers. Participants were 139 HIV-infected adults who underwent medical, psychiatric, and neuropsychological assessments, including a laboratory-based measure of ProM. To assess real-world compliance, participants were instructed to call the examiner 24 hours after the evaluation and report how many hours they had slept. Individuals who failed to correctly comply with these instructions (n=104) demonstrated significantly lower performance on both time- and event-based ProM at baseline than the compliant group (n=35), an effect that was primarily driven by errors of omission. ProM remained a significant predictor of noncompliance after controlling for potential confounders, including demographics (e.g., education), traditional cognitive measures of retrospective memory and executive functions, and psychiatric factors (e.g., depression). Results support the hypothesis that ProM plays a unique role in compliance with health care instructions for HIV disease management and may inform interventions designed to improve treatment outcomes. PMID:20661839

Zogg, Jennifer B.; Woods, Steven Paul; Weber, Erica; Iudicello, Jennifer E.; Dawson, Matthew S.; Grant, Igor

2012-01-01

121

Efficient phagocytosis and laccase activity affect the outcome of HIV-associated cryptococcosis  

PubMed Central

Background. Cryptococcal meningitis (CM) is a leading cause of HIV-associated mortality globally. High fungal burden in cerebrospinal fluid (CSF) at diagnosis and poor fungal clearance during treatment are recognized adverse prognostic markers; however, the underlying pathogenic factors that drive these clinical manifestations are incompletely understood. We profiled a large set of clinical isolates for established cryptococcal virulence traits to evaluate the contribution of C. neoformans phenotypic diversity to clinical presentation and outcome in human cryptococcosis. Methods. Sixty-five C. neoformans isolates from clinical trial patients with matched clinical data were assayed in vitro to determine murine macrophage uptake, intracellular proliferation rate (IPR), capsule induction, and laccase activity. Analysis of the correlation between prognostic clinical and host immune parameters and fungal phenotypes was performed using Spearman’s r, while the fungal-dependent impact on long-term survival was determined by Cox regression analysis. Results. High levels of fungal uptake by macrophages in vitro, but not the IPR, were associated with CSF fungal burden (r = 0.38, P = 0.002) and long-term patient survival (hazard ratio [HR] 2.6, 95% CI 1.2–5.5, P = 0.012). High-uptake strains were hypocapsular (r = –0.28, P = 0.05) and exhibited enhanced laccase activity (r = 0.36, P = 0.003). Fungal isolates with greater laccase activity exhibited heightened survival ex vivo in purified CSF (r = 0.49, P < 0.0001) and resistance to clearance following patient antifungal treatment (r = 0.39, P = 0.003). Conclusion. These findings underscore the contribution of cryptococcal-phagocyte interactions and laccase-dependent melanin pathways to human clinical presentation and outcome. Furthermore, characterization of fungal-specific pathways that drive clinical manifestation provide potential targets for the development of therapeutics and the management of CM. Funding. This work was made possible by funding from the Wellcome Trust (WT088148MF), the Medical Research Council (MR/J008176/1), the NIHR Surgical Reconstruction and Microbiology Research Centre and the Lister Institute for Preventive Medicine (to R.C. May), and a Wellcome Trust Intermediate fellowship (089966, to T. Bicanic). The C. neoformans isolates were collected within clinical trials funded by the British Infection Society (fellowship to T. Bicanic), the Wellcome Trust (research training fellowships WT069991, to A.E. Brouwer and WT081794, to J.N. Jarvis), and the Medical Research Council, United Kingdom (76201). The funding sources had no role in the design or conduct of this study, nor in preparation of the manuscript. PMID:24743149

Sabiiti, Wilber; Robertson, Emma; Beale, Mathew A.; Johnston, Simon A.; Brouwer, Annemarie E.; Loyse, Angela; Jarvis, Joseph N.; Gilbert, Andrew S.; Fisher, Matthew C.; Harrison, Thomas S.; May, Robin C.; Bicanic, Tihana

2014-01-01

122

The Influence of HLA on HIV-Associated Neurocognitive Impairment in Anhui, China  

PubMed Central

Background HLA-DR*04 was identified as a predictor of HIV-Associated neurocognitive disorder (HAND), low CD4 T-cell responses to HIV, and low plasma HIV RNA levels in a U.S. cohort. We hypothesized that low CD4 T-cell activation leads to poor immune control of HIV in the CNS, predisposing to HAND, but also provided fewer target (activated CD4 T-cells) for HIV replication. To assess the consistency of these HLA Class II associations in a new cohort and extend analysis to HLA Class I, HLA types, neurocognitive, and virologic status were examined in a cohort of former plasma donors in China. Methods 178 HIV infected individuals in Anhui China, were HLA typed and underwent neurocognitive evaluations (using locally standardized norms), neuromedical, treatment and virologic assessments at baseline and at 12 months. Results HLA DR*04 was associated with a higher rate of baseline neurocognitive impairment (p?=?0.04), neurocognitive decline (p?=?0.04), and lower levels of HIV RNA in plasma (p?=?0.05). HLA Class I alleles (B*27,57,58,A*03,33) that specify a CD8 T-cell response to conserved HIV sequences were neuroprotective, associated with less impairment at baseline (p?=?0.037), at month 012 (p?=?0.013) and less neurocognitive decline (p?=?0.023) in the interval. Consistent with the theory that effective CD8 T-cell responses require CD4 T-cell support, the HLA DR*04 allele reduced the neuroprotective effect of the Class I alleles. The presence of HLA-DR*04 and the Alzheimer associated allele ApoE4 in the same individual had a synergistic negative effect on cognition (p?=?0.003). Conclusions Despite major background differences between U.S. and Anhui China cohorts, HLA DR*04 predicted neurocognitive impairment and lower plasma HIV RNA levels in both populations. HLA Class I alleles associated with CD8 T-cell control of HIV were associated with protection from HAND, but protection was reduced in the presence of HLA-DR*04. PMID:22693541

Schrier, Rachel D.; Gupta, Saurabh; Riggs, Patricia; Cysique, Lucette A.; Letendre, Scott; Jin, Hua; Spector, Stephen A.; Singh, Kumud K.; Wolfson, Tanya; Wu, Zunyou; Hong, Kun Xue; Yu, Xin; Shi, Chuan; Heaton, Robert K.

2012-01-01

123

Temporal Trends in Presentation and Survival for HIV-Associated Lymphoma in the Antiretroviral Therapy Era  

PubMed Central

Background Lymphoma is the leading cause of cancer-related death among HIV-infected patients in the antiretroviral therapy (ART) era. Methods We studied lymphoma patients in the Centers for AIDS Research Network of Integrated Clinical Systems from 1996 until 2010. We examined differences stratified by histology and diagnosis year. Mortality and predictors of death were analyzed using Kaplan–Meier curves and Cox proportional hazards. Results Of 23 050 HIV-infected individuals, 476 (2.1%) developed lymphoma (79 [16.6%] Hodgkin lymphoma [HL]; 201 [42.2%] diffuse large B-cell lymphoma [DLBCL]; 56 [11.8%] Burkitt lymphoma [BL]; 54 [11.3%] primary central nervous system lymphoma [PCNSL]; and 86 [18.1%] other non-Hodgkin lymphoma [NHL]). At diagnosis, HL patients had higher CD4 counts and lower HIV RNA than NHL patients. PCNSL patients had the lowest and BL patients had the highest CD4 counts among NHL categories. During the study period, CD4 count at lymphoma diagnosis progressively increased and HIV RNA decreased. Five-year survival was 61.6% for HL, 50.0% for BL, 44.1% for DLBCL, 43.3% for other NHL, and 22.8% for PCNSL. Mortality was associated with age (adjusted hazard ratio [AHR] = 1.28 per decade increase, 95% confidence interval [CI] = 1.06 to 1.54), lymphoma occurrence on ART (AHR = 2.21, 95% CI = 1.53 to 3.20), CD4 count (AHR = 0.81 per 100 cell/µL increase, 95% CI = 0.72 to 0.90), HIV RNA (AHR = 1.13 per log10copies/mL, 95% CI = 1.00 to 1.27), and histology but not earlier diagnosis year. Conclusions HIV-associated lymphoma is heterogeneous and changing, with less immunosuppression and greater HIV control at diagnosis. Stable survival and increased mortality for lymphoma occurring on ART call for greater biologic insights to improve outcomes. PMID:23892362

2013-01-01

124

Randomised Pharmacokinetic Trial of Rifabutin with Lopinavir/Ritonavir-Antiretroviral Therapy in Patients with HIV-Associated Tuberculosis in Vietnam  

PubMed Central

Background Rifampicin and protease inhibitors are difficult to use concomitantly in patients with HIV-associated tuberculosis because of drug-drug interactions. Rifabutin has been proposed as an alternative rifamycin, but there is concern that the current recommended dose is suboptimal. The principal aim of this study was to compare bioavailability of two doses of rifabutin (150 mg three times per week and 150 mg daily) in patients with HIV-associated tuberculosis who initiated lopinavir/ritonavir-based antiretroviral therapy in Vietnam. Concentrations of lopinavir/ritonavir were also measured. Methods This was a randomized, open-label, multi-dose, two-arm, cross-over trial, conducted in Vietnamese adults with HIV-associated tuberculosis in Ho Chi Minh City (Clinical trial registry number NCT00651066). Rifabutin pharmacokinetics were evaluated before and after the introduction of lopinavir/ritonavir -based antiretroviral therapy using patient randomization lists. Serial rifabutin and 25-O-desacetyl rifabutin concentrations were measured during a dose interval after 2 weeks of rifabutin 300 mg daily, after 3 weeks of rifabutin 150 mg daily with lopinavir/ritonavir and after 3 weeks of rifabutin 150 mg three times per week with lopinavir/ritonavir. Results Sixteen and seventeen patients were respectively randomized to the two arms, and pharmacokinetic analysis carried out in 12 and 13 respectively. Rifabutin 150 mg daily with lopinavir/ritonavir was associated with a 32% mean increase in rifabutin average steady state concentration compared with rifabutin 300 mg alone. In contrast, the rifabutin average steady state concentration decreased by 44% when rifabutin was given at 150 mg three times per week with lopinavir/ritonavir. With both dosing regimens, 2 – 5 fold increases of the 25-O-desacetyl- rifabutin metabolite were observed when rifabutin was given with lopinavir/ritonavir compared with rifabutin alone. The different doses of rifabutin had no significant effect on lopinavir/ritonavir plasma concentrations. Conclusions Based on these findings, rifabutin 150 mg daily may be preferred when co-administered with lopinavir/ritonavir in patients with HIV-associated tuberculosis. Trial Registration ClinicalTrials.gov NCT00651066 PMID:24465443

Lan, Nguyen Thi Ngoc; Thu, Nguyen Thi Nguyet; Barrail-Tran, Aurélie; Duc, Nguyen Hong; Lan, Nguyen Ngoc; Laureillard, Didier; Thi Xuan Lien, Truong; Borand, Laurence; Quillet, Catherine; Connolly, Catherine; Lagarde, Dominique; Pym, Alexander; Lienhardt, Christian; Dung, Nguyen Huy; Taburet, Anne-Marie; Harries, Anthony D

2014-01-01

125

Management of HIV-associated tuberculosis in resource-limited settings: a state-of-the-art review  

PubMed Central

The HIV-associated tuberculosis (TB) epidemic remains a huge challenge to public health in resource-limited settings. Reducing the nearly 0.5 million deaths that result each year has been identified as a key priority. Major progress has been made over the past 10 years in defining appropriate strategies and policy guidelines for early diagnosis and effective case management. Ascertainment of cases has been improved through a twofold strategy of provider-initiated HIV testing and counseling in TB patients and intensified TB case finding among those living with HIV. Outcomes of rifampicin-based TB treatment are greatly enhanced by concurrent co-trimoxazole prophylaxis and antiretroviral therapy (ART). ART reduces mortality across a spectrum of CD4 counts and randomized controlled trials have defined the optimum time to start ART. Good outcomes can be achieved when combining TB treatment with first-line ART, but use with second-line ART remains challenging due to pharmacokinetic drug interactions and cotoxicity. We review the frequency and spectrum of adverse drug reactions and immune reconstitution inflammatory syndrome (IRIS) resulting from combined treatment, and highlight the challenges of managing HIV-associated drug-resistant TB. PMID:24295487

2013-01-01

126

Uncommon opportunistic fungal infections of oral cavity: A review.  

PubMed

The majority of opportunistic oral mucosal fungal infections are due to Candida albicans and Aspergillus fumigatus species. Mucor and Cryptococcus also have a major role in causing oral infections, whereas Geotrichum, Fusarium, Rhodotorula, Saccharomyces and Penicillium marneffei are uncommon pathogens in the oral cavity. The broad spectrum of clinical presentation includes pseudo-membranes, abscesses, ulcers, pustules and extensive tissue necrosis involving bone. This review discusses various uncommon opportunistic fungal infections affecting the oral cavity including their morphology, clinical features and diagnostic methods. PMID:25328305

Deepa, Ag; Nair, Bindu J; Sivakumar, Tt; Joseph, Anna P

2014-05-01

127

Uncommon opportunistic fungal infections of oral cavity: A review  

PubMed Central

The majority of opportunistic oral mucosal fungal infections are due to Candida albicans and Aspergillus fumigatus species. Mucor and Cryptococcus also have a major role in causing oral infections, whereas Geotrichum, Fusarium, Rhodotorula, Saccharomyces and Penicillium marneffei are uncommon pathogens in the oral cavity. The broad spectrum of clinical presentation includes pseudo-membranes, abscesses, ulcers, pustules and extensive tissue necrosis involving bone. This review discusses various uncommon opportunistic fungal infections affecting the oral cavity including their morphology, clinical features and diagnostic methods. PMID:25328305

Deepa, AG; Nair, Bindu J; Sivakumar, TT; Joseph, Anna P

2014-01-01

128

Trichoderma: the genomics of opportunistic success  

Microsoft Academic Search

Trichoderma is a genus of common filamentous fungi that display a remarkable range of lifestyles and interactions with other fungi, animals and plants. Because of their ability to antagonize plant-pathogenic fungi and to stimulate plant growth and defence responses, some Trichoderma strains are used for biological control of plant diseases. In this Review, we discuss recent advances in molecular ecology

Irina S. Druzhinina; Verena Seidl-Seiboth; Alfredo Herrera-Estrella; Benjamin A. Horwitz; Charles M. Kenerley; Enrique Monte; Prasun K. Mukherjee; Susanne Zeilinger; Igor V. Grigoriev; Christian P. Kubicek

2011-01-01

129

ORIGINAL ARTICLE Phylogeny and Ecophysiology of Opportunistic "Snow Molds"  

E-print Network

ORIGINAL ARTICLE Phylogeny and Ecophysiology of Opportunistic "Snow Molds" from a Subalpine Forest, growth rates, and metabolic potential of cold-adapted fungi from under-snow mats in the subalpine forests-alpine sites in the Rocky Mountains [22]. These fungal communities are ephemeral and rapidly disappear once

Schmidt, Steven K.

130

Analysis of Smartphone User Mobility Traces for Opportunistic Data Collection  

E-print Network

Analysis of Smartphone User Mobility Traces for Opportunistic Data Collection Xiuchao Wu Kenneth N.wu,k.brown,cjs}@cs.ucc.ie ABSTRACT Considering that smartphones are tightly-coupled with their users, the interaction between smartphones and wireless sen- sor networks will play a very important role in pervasive computing

Sreenan, Cormac J.

131

Opportunistic Spatial Gossip over Mobile Social Networks Augustin Chaintreau  

E-print Network

users will access the Internet via their cell-phone or another portable device [10, 12]. In such a new of opportunistic contacts between mobile phones that run an online social network service. Our model includes. WOSN'08, August 18, 2008, Seattle, Washington, USA. Copyright 2008 ACM 978-1-60558-182-8/08/08 ...$5

Chaintreau, Augustin

132

A Message Service for Opportunistic Computing in Disconnected MANETs  

E-print Network

A Message Service for Opportunistic Computing in Disconnected MANETs Abdulkader Benchi, Frédéric. Disconnected mobile ad hoc networks (or D-MANETs) are partially or intermittently connected wireless networks in such conditions, but designing and implementing distributed applications for D-MANETs is still a challeng- ing

Paris-Sud XI, Université de

133

Crowdphysics: Planned and Opportunistic Crowdsourcing for Physical Tasks Adam Sadilek*  

E-print Network

within a wide range of disciplines, from psychology to machine learning, and in- cludes workCrowdphysics: Planned and Opportunistic Crowdsourcing for Physical Tasks Adam Sadilek* Department effectively deliver packages with the crowd? We seek in this paper to answer this concrete question, and more

Krumm, John

134

Opportunistic Routing in Dynamic Ad Hoc Networks: the OPRAH protocol  

Microsoft Academic Search

This paper describes the opportunistic routing in dynamic ad hoc networks, the OPRAH protocols, which uses the air interface to find a more optimal path for each packet in a dynamic network. In the static environment the connectivity is perturbed only by fading between two fixed points, the performance of these protocols depends on how steady a route is. Thus

Cedric Westphal

2006-01-01

135

Trading Structure for Randomness in Wireless Opportunistic Szymon Chachulski  

E-print Network

on top of 802.11. We analyze the theoretical gains provided by opportunistic routing and present the EOTX.11 (WiFi) wireless interfaces. Experimental results from a 20-node wire- less testbed show that MORE would also like to thank the developers of Roofnet, Click and MadWifi, the great building blocks of our

136

On the Feasibility of Effective Opportunistic Spectrum Access  

E-print Network

@cs.ucsb.edu ABSTRACT Dynamic spectrum access networks are designed to allow today's bandwidth hungry "secondary devices, Reliability Keywords Opportunistic spectrum access, Channel bundling, Measurement 1. INTRODUCTION Radio network depend on the amount of spectrum it can access. Despite its recognized value, current policies

Zhao, Ben Y.

137

DISTRIBUTED COGNITIVE MAC FOR ENERGY-CONSTRAINED OPPORTUNISTIC SPECTRUM ACCESS  

E-print Network

existence of spectrum opportunities. Real measurements show that, at any given time and location, a large opportunities among secondary users so that the network-level spectrum efficiency is maximized subject to someDISTRIBUTED COGNITIVE MAC FOR ENERGY-CONSTRAINED OPPORTUNISTIC SPECTRUM ACCESS Yunxia Chen, Qing

Islam, M. Saif

138

Bursty Traffic in Energy-Constrained Opportunistic Spectrum Access  

E-print Network

]. Measurements obtained from spectrum monitoring test- beds demonstrate the Makovian transition between busy channels even if its buffer is empty. II. SYSTEM MODEL A. Primary Network Model We consider a spectrumBursty Traffic in Energy-Constrained Opportunistic Spectrum Access Yunxia Chen, Qing Zhao

Islam, M. Saif

139

Channel Allocation for Fairness in Opportunistic Spectrum Access Networks  

Microsoft Academic Search

In this paper, we investigate the fairness between two secondary user (SU) groups in an opportunistic spectrum access networks (OSA). First, for a given number of allocated channels the throughput of each SU group is analyzed in terms of its forced termination and blocking probabilities using continuous time Markov model. Based on these calculations, the fairness between two SU groups

Waqas Ahmed; Jason Gao; Michael Faulkner

2010-01-01

140

Bursty Traffic in Energy-Constrained Opportunistic Spectrum Access  

E-print Network

. Modeling of spectrum occupancy has been addressed in [7]. Measurements obtained from spectrum monitoring independently and selfishly seek spectrum opportunities in a slotted primary network. We formulateBursty Traffic in Energy-Constrained Opportunistic Spectrum Access Yunxia Chen, Qing Zhao

Islam, M. Saif

141

On the Effectiveness of an Opportunistic Traffic Management System  

E-print Network

1 On the Effectiveness of an Opportunistic Traffic Management System for Vehicular Networks Ilias. A possible way to deal with this problem is to have transportation authorities distribute traffic information. Such traffic information can be gathered by relying on static sensors placed at specific road locations (e

Mascolo, Cecilia

142

Congestion management in opportunistically connected networks using repeated games  

Microsoft Academic Search

In opportunistically connected networks, custody transfer provides a certain degree of reliability as a custodian node cannot discard a message unless its life time expires or the custody is transferred to another node with a commitment. This creates a challenging decision making problem at a node in determining whether to accept a custody transfer: on one hand, it is beneficial

Guohua Zhang; Yonghe Liu

2008-01-01

143

Opportunistic Spectrum Sharing in Cognitive MIMO Wireless Networks  

Microsoft Academic Search

Cognitive radio has been recently proposed as a promising technology to improve the spectrum utilization. In this paper, we consider the spectrum sharing between a large number of cognitive radio users and a licensed user in order to enhance the spectrum efficiency. With the deployment of M antennas at the cognitive base station, an opportunistic spectrum sharing approach is proposed

Karama Hamdi; Wei Zhang; Khaled Ben Letaief

2009-01-01

144

Modelling the healthcare costs of an opportunistic chlamydia screening programme  

Microsoft Academic Search

Objectives: To estimate the average cost per screening offer, cost per testing episode and cost per chlamydia positive episode for an opportunistic chlamydia screening programme (including partner management), and to explore the uncertainty of parameter assumptions, based on the costs to the healthcare system.Methods: A decision tree was constructed and parameterised using empirical data from a chlamydia screening pilot study

E J Adams; D S LaMontagne; A R Johnston; J M Pimenta; K A Fenton; W J Edmunds

2004-01-01

145

Board of Directors and Opportunistic Earnings Management: Evidence from India  

Microsoft Academic Search

Abstract Inthis paper we investigate ,the impact ,of board characteristics on opportunistic, earnings management in the context of a large emerging economy, India. While the role of company boards in earnings management has been examined in developed markets setting, particularly the US and UK, understanding their effectiveness in emerging markets like India is particularly important due to differences ,that exist

Jayati Sarkar; Subrata Sarkar; Kaustav Sen

2006-01-01

146

What's Happening?: Promoting Community Awareness through Opportunistic, Peripheral Interfaces  

E-print Network

community awareness in such situations. In particular, a large body of research in Computer SupportedWhat's Happening?: Promoting Community Awareness through Opportunistic, Peripheral Interfaces Qiang of Technology Atlanta, GA 30332-0280 USA +1 404 894 5617 stasko@cc.gatech.edu ABSTRACT Maintaining an awareness

Stasko, John T.

147

What's Happening?: Promoting Community Awareness through Opportunistic, Peripheral Interfaces  

E-print Network

What's Happening?: Promoting Community Awareness through Opportunistic, Peripheral Interfaces Qiang Atlanta, GA 30332-0280 USA +1 404 894 5617 stasko@cc.gatech.edu ABSTRACT Maintaining an awareness-supported cooperative work General Terms Algorithms, Design, Experimentation, Human Factors Keywords Community awareness

Stasko, John T.

148

Arcanobacterium pyogenes : molecular pathogenesis of an animal opportunist  

Microsoft Academic Search

Arcanobacterium pyogenes is a commensal and an opportunistic pathogen of economically important livestock, causing diseases as diverse as mastitis, liver abscessation and pneumonia. This organism possesses a number of virulence factors that contribute to its pathogenic potential. A. pyogenes expresses a cholesterol-dependent cytolysin, pyolysin, which is a haemolysin and is cytolytic for immune cells, including macrophages. Expression of pyolysin is

B. Helen Jost; Stephen J. Billington

2005-01-01

149

Opportunistic media access for multirate ad hoc networks  

Microsoft Academic Search

The IEEE 802.11 wireless media access standard supports multiple data rates at the physical layer. Moreover, various auto rate adaptation mechanisms at the medium access layer have been proposed to utilize this multi-rate capability by automatically adapting the transmission rate to best match the channel conditions. In this paper, we introduce the Opportunistic Auto Rate (OAR) protocol to better exploit

Bahareh Sadeghi; Vikram Kanodia; Ashutosh Sabharwal; Edward W. Knightly

2002-01-01

150

Opportunistic Media Access for Multirate Ad Hoc Networks  

Microsoft Academic Search

The IEEE 802.11 wireless media access standard supports multiple data rates at the physical layer. Moreover, vari- ous auto rate adaptation mechanisms at the medium access layer have been proposed to utilize this multi-rate capabil- ity by automatically adapting the transmission rate to best match the channel conditions. In this paper, we introduce the Opportunistic Auto Rate (OAR) protocol to

B. Sadeghi; V. Kanodia; A. Sabharwal; E. Knightly

151

Cooperative Opportunistic Large Array Approach for Cognitive Radio Networks  

E-print Network

1 Cooperative Opportunistic Large Array Approach for Cognitive Radio Networks Vandana Rohokale E-mail: cornean@math.aau.dk Abstract-- Cognitive Radio (CR) seems to be a promising solution increase their effective QoS via cooperation. For cognitive radio networks, sharing of primary user

Hansen, René Rydhof

152

Cooperation and Learning in Multiuser Opportunistic Spectrum Access  

E-print Network

Cooperation and Learning in Multiuser Opportunistic Spectrum Access Hua Liu§ , Bhaskar is to investigate whether and how contending secondary users should cooperate and learn from "mistakes" (collisions the secondary users, a learning-based approach involving use of collision feedback information, and a single

Islam, M. Saif

153

Throughput-oriented channel assignment for opportunistic spectrum access networks  

Microsoft Academic Search

Cognitive radio (CR) is a revolutionary technology in wireless communications that enhances spectrum utilization by allowing opportunistic and dynamic spectrum access. One of the key challenges in this domain is how CR users cooperate to dynamically access the available spectrum opportunities in order to maximize the overall perceived throughput. In this paper, we consider the coordinated spectrum access problem in

Haythem Ahmad Bany Salameh

2011-01-01

154

Impact of Human Mobility on Opportunistic Forwarding Algorithms  

E-print Network

THE increasing popularity of devices equipped with wireless network interfaces (such as cell phones or PDAsImpact of Human Mobility on Opportunistic Forwarding Algorithms Augustin Chaintreau, Pan Hui, Jon models. In this paper, we study how this newly uncovered characteristic of human mobility impacts one

Chaintreau, Augustin

155

135 HIV-associated immunodeficiency despite potent antiretroviral therapy with CD4 T cell reconstitution  

PubMed Central

CD4 T cell reconstitution in patients with HIV is associated with increased responses to conventional vaccines and improved resistance to opportunistic infections. However, prolonged therapy fails to replenish a capacity for immune control over HIV and patients who interrupt therapy inevitably rebound to pre-treatment viral burden in plasma. Only elite patients, termed NVS or natural virus suppressors (1), control viremia to undetectable levels in the absence of therapy. Our earlier studies on NVS patients showed that this group was distinguished from all other HIV patients by the presence of normal levels of CD56+ V 2V 2 T cells in blood (2) reflecting reconstitution of the T cell receptor repertoire through new cell synthesis (3). The CD56 marker identifies cytotoxic effector lymphocytes including NK, CD8, T and NKT subsets, but it’s function remains unknown. We have now shown persistent depression of CD56 expression on CD8 T cells from HIV+ individuals except for NVS patients where the levels approach those found in normal controls. The CD56+ CD8 T cell subset is highly responsive to stimulus, expresses high levels of perforin/granzyme and the small population remaining in HIV patients on therapy, also express the immune exhaustion marker TIM-3, indicating cells may be lost through an apoptosis mechanism. The persisting defect in CD56 expression for 2 T cells subsets is consistent with a lack of cytolytic effector function and is present in patients with complete virus suppression for many years due to treatment, long after the T cell population is refreshed by new cell synthesis. The block to lytic effector function may explain why treated patients fail to eradicate viral reservoirs; this mechanism is a key target for new therapies designed to cure HIV disease. 1. M. M. Sajadi, A. Heredia, N. Le, N. T. Constantine, R. R. Redfield, HIV-1 natural viral suppressors: control of viral replication in the absence of therapy. AIDS 21, 517 (2007). 2. D. J. Riedel et al. Natural viral suppressors of HIV-1 have a unique capacity to maintain gamma delta T cells. AIDS 23, 1955 (2009). 3. S. Chaudhry, C. Cairo, V. Venturi, C. D. Pauza, The gamma delta T cell receptor repertoire is reconstituted in HIV patients after prolonged antiretroviral therapy. AIDS epub ahead of print, (2013).

Poonia, Bhawna; Chaudry, Suchita; Li, Haishan; Cairo, Cristiana; Pauza, C. David

2014-01-01

156

Phaeohyphomycoses, Emerging Opportunistic Diseases in Animals  

PubMed Central

Emerging fungal diseases due to black yeasts and relatives in domestic or wild animals and in invertebrates or cold- and warm-blooded vertebrates are continually being reported, either as novel pathogens or as familiar pathogens affecting new species of hosts. Different epidemiological situations can be distinguished, i.e., occurrence as single infections or as zoonoses, and infection may occur sporadically in otherwise healthy hosts. Such infections are found mostly in mammals but also in cold-blooded animals, are frequently subcutaneous or cerebral, and bear much similarity to human primary disorders. Infections of the nervous system are mostly fatal, and the source and route of infection are currently unknown. A third epidemiological situation corresponds to pseudoepidemics, i.e., infection of a large host population due to a common source. It is often observed and generally hypothesized that the susceptible animals are under stress, e.g., due to poor housing conditions of mammals or to a change of basins in the case of fishes. The descriptions in this article represent an overview of the more commonly reported and recurring black fungi and the corresponding diseases in different types of animals. PMID:23297257

Seyedmousavi, S.; Guillot, J.

2013-01-01

157

Gender based violence as a risk factor for HIV-associated risk behaviors among female sex workers in Armenia.  

PubMed

This cross-sectional study identified the prevalence of gender based violence (GBV) and examined its association with sexual risk behavior among female sex workers (FSWs). Among 120 participants between ages 20 and 52, a total of 56.7 % reported lifetime GBV. Multivariate analyses revealed that GBV was significantly associated with inconsistent condom use, unprotected sex, condom misuse, fear of client reaction to requests of condom use, self-reported history of STIs, and earlier age of initiation of sex work. GBV must be considered an urgent public health priority among FSWs in Armenia. Interventions addressing FSWs, in addition to targeting skill-based, sexual risk reduction must also introduce a discourse among FSWs, sexual partners, clients and community members about the role of GBV in HIV-associated risk behaviors and infection. Structural level initiatives must address economic opportunities for women, health-sector policies and responses to FSWs' health needs, law enforcement training and societal norms toward women. PMID:22760740

Lang, Delia L; Salazar, Laura F; DiClemente, Ralph J; Markosyan, Karine

2013-02-01

158

Focused assessment with sonography for HIV-associated tuberculosis (FASH): a short protocol and a pictorial review  

PubMed Central

Background Ultrasound can rapidly identify abnormal signs, which in high prevalence settings, are highly suggestive of extra-pulmonary tuberculosis (EPTB). Unfortunately experienced sonographers are often scarce in these settings. Methods A protocol for focused assessment with sonography for HIV-associated tuberculosis (FASH) which can be used by physicians who are relatively inexperienced in ultrasound was developed. Results The technique as well as normal and pathological findings are described and the diagnostic and possible therapeutic reasoning explained. The protocol is intended for settings where the prevalence of HIV/TB co-infected patients is high. Conclusion FASH is suitable for more rapid identification of EPTB even at the peripheral hospital level where other imaging modalities are scarce and most of the HIV and TB care will be delivered in the future. PMID:23171481

2012-01-01

159

Performance modeling of an opportunistic spectrum sharing wireless network with unreliable sensing  

Microsoft Academic Search

Opportunistic Spectrum Sharing (OSS) has recently attracted increasing interest. We analytically model a wireless network that allows opportunistic spectrum sharing and analyze its performance through a queueing theoretic framework. The OSS system consists of the secondary users opportunistically sharing a set of spectrum resources with the primary users over a coverage area. The secondary users equipped with cognitive radios sense

Shensheng Tang

2010-01-01

160

Human Immunodeficiency Virus-Associated Gastrointestinal Disease: Common Endoscopic Biopsy Diagnoses  

PubMed Central

The gastrointestinal (GI) tract is a major site of disease in HIV infection: almost half of HIV-infected patients present with GI symptoms, and almost all patients develop GI complications. GI symptoms such as anorexia, weight loss, dysphagia, odynophagia, abdominal pain, and diarrhea are frequent and usually nonspecific among these patients. Endoscopy is the diagnostic test of choice for most HIV-associated GI diseases, as endoscopic and histopathologic evaluation can render diagnoses in patients with non-specific symptoms. In the past three decades, studies have elucidated a variety of HIV-associated inflammatory, infectious, and neoplastic GI diseases, often with specific predilection for various sites. HIV-associated esophageal disease, for example, commonly includes candidiasis, cytomegalovirus (CMV) and herpes simplex virus (HSV) infection, Kaposi's sarcoma (KS), and idiopathic ulceration. Gastric disease, though less common than esophageal disease, frequently involves CMV, Mycobacterium avium-intracellulare (MAI), and neoplasia (KS, lymphoma). Small bowel biopsies and intestinal aspirates from HIV-infected patients often show HIV enteropathy, MAI, protozoa (Giardia, Isospora, Cryptosporidia, amebae, Microsporidia), and helminths (Strongyloides stercoralis). Colorectal biopsies demonstrate viral (CMV, HSV), bacterial (Clostridia, Salmonella, Shigella, Campylobacter), fungal (cryptococcosis, histoplasmosis), and neoplastic (KS, lymphoma) processes. Herein, we review HIV-associated GI pathology, with emphasis on common endoscopic biopsy diagnoses. PMID:21559197

Bhaijee, Feriyl; Subramony, Charu; Tang, Shou-Jiang; Pepper, Dominique J.

2011-01-01

161

Determinants of Mortality in a Combined Cohort of 501 Patients With HIV-Associated Cryptococcal Meningitis: Implications for Improving Outcomes  

PubMed Central

Background.?Cryptococcal meningitis (CM) is a leading cause of death in individuals infected with human immunodeficiency virus (HIV). Identifying factors associated with mortality informs strategies to improve outcomes. Methods.?Five hundred one patients with HIV-associated CM were followed prospectively for 10 weeks during trials in Thailand, Uganda, Malawi, and South Africa. South African patients (n = 266) were followed for 1 year. Similar inclusion/exclusion criteria were applied at all sites. Logistic regression identified baseline variables independently associated with mortality. Results.?Mortality was 17% at 2 weeks and 34% at 10 weeks. Altered mental status (odds ratio [OR], 3.1; 95% confidence interval [CI], 1.7–5.9), high cerebrospinal fluid (CSF) fungal burden (OR, 1.4 per log10 colony-forming units/mL increase; 95% CI, 1.0–1.8), older age (>50 years; OR, 3.9; 95% CI, 1.4–11.1), high peripheral white blood cell count (>10 × 109 cells/L; OR, 8.7; 95% CI, 2.5–30.2), fluconazole-based induction treatment, and slow clearance of CSF infection were independently associated with 2-week mortality. Low body weight, anemia (hemoglobin <7.5 g/dL), and low CSF opening pressure were independently associated with mortality at 10 weeks in addition to altered mental status, high fungal burden, high peripheral white cell count, and older age. In those followed for 1 year, overall mortality was 41%. Immune reconstitution inflammatory syndrome occurred in 13% of patients and was associated with 2-week CSF fungal burden (P = .007), but not with time to initiation of antiretroviral therapy (ART). Conclusions.?CSF fungal burden, altered mental status, and rate of clearance of infection predict acute mortality in HIV-associated CM. The results suggest that earlier diagnosis, more rapidly fungicidal amphotericin-based regimens, and prompt immune reconstitution with ART are priorities for improving outcomes. PMID:24319084

Jarvis, Joseph N.; Bicanic, Tihana; Loyse, Angela; Namarika, Daniel; Jackson, Arthur; Nussbaum, Jesse C.; Longley, Nicky; Muzoora, Conrad; Phulusa, Jacob; Taseera, Kabanda; Kanyembe, Creto; Wilson, Douglas; Hosseinipour, Mina C.; Brouwer, Annemarie E.; Limmathurotsakul, Direk; White, Nicholas; van der Horst, Charles; Wood, Robin; Meintjes, Graeme; Bradley, John; Jaffar, Shabbar; Harrison, Thomas

2014-01-01

162

Activation status of integrated stress response pathways in neurones and astrocytes of HIV-associated neurocognitive disorders (HAND) cortex  

PubMed Central

Aims Combined anti-retroviral therapy (cART) has led to a reduction in the incidence of HIV-associated dementia (HAD), a severe motor/cognitive disorder afflicting HIV(+) patients. However, the prevalence of subtler forms of neurocognitive dysfunction, which together with HAD are termed HIV-associated neurocognitive disorders (HAND), continues to escalate in the post-cART era. The microgliosis, astrogliosis, dendritic damage, and synaptic and neuronal loss observed in autopsy cases suggest an underlying neuroinflammatory process, due to the neurotoxic factors released by HIV-infected/activated macrophages/ microglia in the brain, might underlie the pathogenesis of HAND in the post-cART era. These factors are known to induce the integrated stress response (ISR) in several neurodegenerative diseases; we have previously shown that BiP, an indicator of general ISR activation, is upregulated in cortical autopsy tissue from HIV-infected patients. The ISR is composed of three pathways, each with its own initiator protein: PERK, IRE1? and ATF6. Methods To further elucidate the specific ISR pathways activated in the central nervous system of HAND patients, we examined the protein levels of several ISR proteins, including ATF6, peIF2? and ATF4, in cortical tissue from HIV-infected patients. Results The ISR does not respond in an all-or-none fashion in HAND, but rather demonstrates a nuanced activation pattern. Specifically, our studies implicate the ATF6 pathway of the ISR as a more likely candidate than the PERK pathway for increases in BiP levels in astrocytes. Conclusion These findings begin to characterize the nature of the ISR response in HAND and provide potential targets for therapeutic intervention in this disease. PMID:21883374

Akay, C.; Lindl, K. A.; Shyam, N.; Nabet, B.; Goenaga-Vazquez, Y.; Ruzbarsky, J.; Wang, Y.; Kolson, D. L.; Jordan-Sciutto, K. L.

2013-01-01

163

High incidence of HIV-associated mortality among black and Hispanic infants and women of childbearing age in the United States 1990-2001.  

PubMed

This study examined HIV-associated mortality in infants and in women of childbearing age (15-44 years) in the United States from 1990-2001. HIV-associated deaths were identified from national vital records using multiple cause-of-death data. HIV-associated mortality was higher in black and Hispanic women than in white women (rate ratio(black) = 13.5, 95% CI = 13.2-13.8; rate ratio(Hispanic) = 2.4, 95% CI = 1.9-3.2). Racial/ethnic trends in infant mortality rates from HIV reflected trends observed in women (rate ratio(black) = 16.3, 95% CI = 13.5-19.7; rate ratio(Hispanic) = 3.4, 95% CI = 3.3-3.5). HIV-associated mortality decreased in infants and in women of childbearing age following the availability of highly active antiretroviral therapy, but the decrease was considerably less marked in black women than in women of other racial/ethnic groups. Our findings indicate the need for increased emphasis on prevention of HIV mortality in black and Hispanic women and infants. Reduction of HIV prevalence in young women may also prevent infant mortality from HIV by reducing mother-to-child transmission. PMID:16010175

Redelings, Matthew D; Frye, Douglas M; Sorvillo, Frank

2005-08-01

164

Towards a Resource Reservation Approach for an Opportunistic Computing Environment  

NASA Astrophysics Data System (ADS)

Advanced reservation has been used in grid environments to provide quality of service (QoS) and to guarantee resources available at the execution time. However, in grid subtypes, such as opportunistic grid computing, it is a challenge provides QoS and guarantee of availability resources. In this article, we propose a new advanced reservation approach which offers to a user the possibility to select resources in advance for a future utilization. Therefore, the main goal of this proposal is to offer a best effort feature to a user from an opportunistic configuration. In these types of environments, it is not possible to provide QoS, because, usually, there are no guarantees of resources availability and, consequently, the execution of users applications. In addition, this research work provides a way to organize executions, what it can improve the scheduling and system operations. Experimental results, carried out through a case study, shown the efficiency and relevance of our proposal.

Gomes, Eliza; Dantas, M. A. R.

2014-10-01

165

Opportunistic use of cognitive smokescreens by araneophagic jumping spiders  

Microsoft Academic Search

.   Little is known about how a prey species' cognitive limitations might shape a predator's prey-capture strategy. A specific\\u000a hypothesis is investigated: predators take advantage of times when the prey's attention is focussed on its own prey. Portia fimbriata, an araneophagic jumping spider (Salticidae) from Queensland, is shown in a series of 11 experiments to exploit opportunistically\\u000a a situation in

Robert R. Jackson; Simon D. Pollard; Ana M. Cerveira

2002-01-01

166

Social-based autonomic routing in opportunistic networks  

NASA Astrophysics Data System (ADS)

In opportunistic networks end-to-end communication between users does not require a continuous end-to-end path between source and destination. Network protocols are designed to be extremely resilient to events such as long partitions, node disconnections, etc, which are very features of this type of self-organizing ad hoc networks. This is achieved by temporarily storing messages at intermediate nodes, waiting for future opportunities to forward them towards the destination. The mobility of users plays a key role in opportunistic networks. Thus, providing accurate models of mobility patterns is one of the key research areas. In this chapter we firstly focus on this issue, with special emphasis on a class of social-aware models. These models are based on the observation that people move because they are attracted towards other people they have social relationships with, or towards physical places that have special meaning with respect to their social behavior. Another key research area in opportunistic networks is clearly designing routing and forwarding schemes. In this chapter we provide a survey of the main approaches to routing in purely infrastructure-less opportunistic networks, by classifying protocols based on the amount of context information they exploit.We then provide an extensive quantitative comparison between representatives of protocols that do not use any context information, and protocols that manage and exploit a rich set of context information. We mainly focus on the suitability of protocols to adapt to the dynamically changing network features, as resulting from the user movement patterns that are driven by their social behavior. Our results show that context-aware routing is extremely adaptive to dynamic networking scenarios, and, with respect to protocols that do not use any context information, is able to provide similar performance in terms of delay and loss rate, by using just a small fraction of the network resources.

Boldrini, Chiara; Conti, Marco; Passarella, Andrea

167

Genetically Modified Peripheral Blood Stem Cell Transplant in Treating Patients With HIV-Associated Non-Hodgkin or Hodgkin Lymphoma  

ClinicalTrials.gov

Adult Nasal Type Extranodal NK/T-cell Lymphoma; AIDS-related Diffuse Large Cell Lymphoma; AIDS-related Diffuse Mixed Cell Lymphoma; AIDS-related Diffuse Small Cleaved Cell Lymphoma; AIDS-related Immunoblastic Large Cell Lymphoma; AIDS-related Lymphoblastic Lymphoma; AIDS-related Peripheral/Systemic Lymphoma; AIDS-related Small Noncleaved Cell Lymphoma; Anaplastic Large Cell Lymphoma; Angioimmunoblastic T-cell Lymphoma; Cutaneous B-cell Non-Hodgkin Lymphoma; Extranodal Marginal Zone B-cell Lymphoma of Mucosa-associated Lymphoid Tissue; Hepatosplenic T-cell Lymphoma; HIV-associated Hodgkin Lymphoma; Intraocular Lymphoma; Nodal Marginal Zone B-cell Lymphoma; Noncutaneous Extranodal Lymphoma; Peripheral T-cell Lymphoma; Recurrent Adult Burkitt Lymphoma; Recurrent Adult Diffuse Large Cell Lymphoma; Recurrent Adult Diffuse Mixed Cell Lymphoma; Recurrent Adult Diffuse Small Cleaved Cell Lymphoma; Recurrent Adult Grade III Lymphomatoid Granulomatosis; Recurrent Adult Hodgkin Lymphoma; Recurrent Adult Immunoblastic Large Cell Lymphoma; Recurrent Adult Lymphoblastic Lymphoma; Recurrent Adult T-cell Leukemia/Lymphoma; Recurrent Cutaneous T-cell Non-Hodgkin Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Grade 3 Follicular Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Mycosis Fungoides/Sezary Syndrome; Recurrent Small Lymphocytic Lymphoma; Refractory Hairy Cell Leukemia; Small Intestine Lymphoma; Splenic Marginal Zone Lymphoma; Stage I AIDS-related Lymphoma; Stage II AIDS-related Lymphoma; Stage III AIDS-related Lymphoma; Stage IV AIDS-related Lymphoma; T-cell Large Granular Lymphocyte Leukemia; Testicular Lymphoma; Waldenström Macroglobulinemia

2014-06-23

168

Methamphetamine and Inflammatory Cytokines Increase Neuronal Na+/K+-ATPase Isoform 3: Relevance for HIV Associated Neurocognitive Disorders  

PubMed Central

Methamphetamine (METH) abuse in conjunction with human immunodeficiency virus (HIV) exacerbates neuropathogenesis and accelerates neurocognitive impairments in the central nervous system (CNS), collectively termed HIV Associated Neurocognitive Disorders (HAND). Since both HIV and METH have been implicated in altering the synaptic architecture, this study focused on investigating alterations in synaptic proteins. Employing a quantitative proteomics approach on synaptosomes isolated from the caudate nucleus from two groups of rhesus monkeys chronically infected with simian immunodeficiency virus (SIV) differing by one regimen, METH treatment, we identified the neuron specific Na+/K+-ATPase alpha 1 isoform 3 (ATP1A3) to be up regulated after METH treatment, and validated its up regulation by METH in vitro. Further studies on signaling mechanisms revealed that the activation of ATP1A3 involves the extracellular regulated kinase (ERK) pathway. Given its function in maintaining ionic gradients and emerging role as a signaling molecule, changes in ATP1A3 yields insights into the mechanisms associated with HAND and interactions with drugs of abuse. PMID:22662178

Pendyala, Gurudutt; Buescher, James L.; Fox, Howard S.

2012-01-01

169

Planning Deficits in HIV-Associated Neurocognitive Disorders: Component Processes, Cognitive Correlates, and Implications for Everyday Functioning  

PubMed Central

Executive dysfunction remains among the most prevalent cognitive domains impaired in persons with HIV-associated neurocognitive disorders (HAND). However, little is known specifically about the cognitive architecture or everyday functioning implications of planning, which is an aspect of executive functions involving the identification, organization, and completion of sequential behaviors toward the accomplishment of a goal. The current study examined these issues using the Tower of LondonDX in 53 individuals with HAND, 109 HIV-infected persons without HAND, and 82 seronegative participants. The HAND+ group performed significantly more poorly than HIV-infected individuals without HAND on number of correct moves, total moves, execution time, time violations, and rule violations. Within the HIV+ group as a whole, greater total move scores and rule violations were most strongly associated with executive dysfunction. Of clinical relevance, elevated total moves and rule violations were significant, independent predictors of self-reported declines in instrumental activities of daily living and unemployment status in HIV. These results suggest that planning accuracy, efficiency, and rule-bound control are impaired in HAND, and may meaningfully affect more cognitively complex aspects of everyday living. PMID:22731608

Cattie, Jordan E.; Doyle, Katie; Weber, Erica; Grant, Igor; Woods, Steven Paul

2012-01-01

170

Potential role of IL-18 in the immunopathogenesis of AIDS, HIV-associated lipodystrophy and related clinical conditions.  

PubMed

IL-18 is a pleiotropic and multifunctional proinflammatory cytokine that is often produced in response to a viral infection. The biological activities of the cytokine are tightly controlled by its natural antagonist, IL-18 binding protein (IL-18BP), as well as by activation of caspase-1, which cleaves the precursor form of IL-18 into its biologically mature form. The cytokine plays an important role in both innate and adaptive antiviral immune responses. Depending upon the context, it can promote TH1, TH2 and TH17 responses. Increased serum concentrations of IL-18 and concomitantly decreased concentrations of its natural antagonist have been described in HIV-infected persons as compared to HIV-seronegative healthy subjects. We discuss in this review article how increased biological activities of IL-18 contribute towards immunopathogenesis of AIDS, HIV-associated lipodystrophy syndrome and related metabolic disturbances. While the advent of potent anti-HIV drugs has significantly enhanced life span of HIV-infected patients, it has also increased the number of these patients suffering from metabolic disorders. The cytokine may prove to be a useful target for therapeutic intervention in these patients. PMID:19954415

Iannello, Alexandre; Samarani, Suzanne; Debbeche, Olfa; Boulassel, Mohamed-Rachid; Tremblay, Cécile; Toma, Emil; Routy, Jean-Pierre; Ahmad, Ali

2010-03-01

171

The 12th International Workshops on Opportunistic Protists (IWOP-12)  

PubMed Central

The 12th International Workshops on Opportunistic Protists (IWOP-12) was held in August 2012 in Tarrytown, New York. The objectives of the IWOP meetings are to: (1) serve as a forum for exchange of new information among active researchers concerning the basic biology, molecular genetics, immunology, biochemistry, pathogenesis, drug development, therapy, and epidemiology of these immunodeficiency-associated pathogenic eukaryotic microorganisms that are seen in patients with AIDS and (2) foster the entry of new and young investigators into these underserved research areas. The IWOP meeting focuses on opportunistic protists, e.g. the free-living amoebae, Pneumocystis, Cryptosporidium, Toxoplasma, the Microsporidia, and kinetoplastid flagellates. This conference represents the major conference that brings together research groups working on these opportunistic pathogens. Slow but steady progress is being achieved on understanding the biology of these pathogenic organisms, their involvement in disease causation in both immune-deficient and immune-competent hosts, and is providing critical insights into these emerging and reemerging pathogens. This IWOP meeting demonstrated the importance of newly developed genomic level information for many of these pathogens and how analysis of such large data sets is providing key insights into the basic biology of these organisms. A great concern is the loss of scientific expertise and diversity in the research community due to the ongoing decline in research funding. This loss of researchers is due to the small size of many of these research communities and a lack of appreciation by the larger scientific community concerning the state of art and challenges faced by researchers working on these organisms. PMID:23560871

Weiss, Louis M.; Cushion, Melanie T.; Didier, Elizabeth; Xiao, Lihua; Marciano-Cabral, Francine; Sinai, Anthony P.; Matos, Olga; Calderon, Enrique J.; Kaneshiro, Edna S.

2013-01-01

172

NGX-4010, a capsaicin 8% patch, for the treatment of painful HIV-associated distal sensory polyneuropathy: integrated analysis of two phase III, randomized, controlled trials  

PubMed Central

Background HIV-associated distal sensory polyneuropathy (HIV-DSP) is the most frequently reported neurologic complication associated with HIV infection. NGX-4010 is a capsaicin 8% dermal patch with demonstrated efficacy in the treatment of HIV-DSP. Data from two phase III, double-blind studies were integrated to further analyze the efficacy and safety of NGX-4010 and explore the effect of demographic and baseline factors on NGX-4010 treatment in HIV-DSP. Methods Data from two similarly designed studies in which patients with HIV-DSP received NGX-4010 or a low-concentration control patch (capsaicin 0.04% w/w) for 30 or 60 minutes were integrated. Efficacy assessments included the mean percent change from baseline in Numeric Pain Rating Scale (NPRS) scores to Weeks 2–12. Safety and tolerability assessments included adverse events (AEs) and pain during and after treatment. Results Patients (n = 239) treated with NGX-4010 for 30 minutes demonstrated significantly (p = 0.0026) greater pain relief compared with controls (n = 100); the mean percent change in NPRS scores from baseline to Weeks 2–12 was ?27.0% versus ?15.7%, respectively. Patients who received a 60-minute application of NGX-4010 (n = 243) showed comparable pain reductions (?27.5%) to patients treated for 30 minutes, but this was not statistically superior to controls (n = 115). NGX-4010 was effective regardless of gender, baseline pain score, duration of HIV-DSP, or use of concomitant neuropathic pain medication, although NGX-4010 efficacy was greater in patients not receiving concomitant neuropathic pain medications. NGX-4010 was well tolerated; the most common AEs were application-site pain and erythema, and most AEs were mild to moderate. The transient increase in pain associated with NGX-4010 treatment decreased the day after treatment and returned to baseline by Day 2. Conclusions A single 30-minute application of NGX-4010 provides significant pain relief for at least 12 weeks in patients with HIV-DSP and is well tolerated. Trial registration C107 = NCT00064623; C119 = NCT00321672 PMID:23351618

2013-01-01

173

Opportunistic Ports and Spaces of Exchange in Late Roman Cyprus  

NASA Astrophysics Data System (ADS)

Ports served not only as interfaces between land and sea, but as central gathering spaces for economic and cultural exchange. Drawing on case studies from the eastern Mediterranean island of Cyprus, this paper situates opportunistic ports lacking built facilities within a broader socioeconomic context of diverse maritime communications, expanding rural settlement, and increased agricultural productivity during late antiquity. Though simple, these sites served as active agents in the development of new maritime networks as well as local markets throughout their hinterlands, adding flexibility and dynamism to the economic ties between city, countryside, and the wider late Roman world.

Leidwanger, Justin

2013-12-01

174

Screening for HIV-Associated Peripheral Neuropathy in Resource-Limited Settings  

PubMed Central

INTRODUCTION Peripheral neuropathy is the most common neurological complication of HIV but is widely under-diagnosed in resource-limited settings. We investigated the utility of screening tools administered by non-physician health care workers (HCW) and quantitative sensory testing (QST) administered by trained individuals for identification of moderate/severe neuropathy. METHODS We enrolled 240 HIV-infected outpatients using two-stage cluster randomized sampling. HCWs administered the several screening tools. Trained study staff performed QST. Tools were validated against a clinical diagnosis of neuropathy. RESULTS Participants were 65% women, mean age 36.4 years, median CD4 324 cells/?L. 65% were taking antiretrovirals, and 18% had moderate/severe neuropathy. The screening tests were 76% sensitive in diagnosing moderate/severe neuropathy with negative predictive values of 84–92%. QST was less sensitive but more specific. DISCUSSION Screening tests administered by HCW have excellent negative predictive values and are promising tools for scale-up in resource-limited settings. QST shows promise for research use. PMID:24037693

Cettomai, Deanna; Kwasa, Judith K.; Birbeck, Gretchen L.; Price, Richard W.; Cohen, Craig R.; Bukusi, Elizabeth A.; (OB/Gyn), MMed; Kendi, Caroline; Meyer, Ana-Claire L.

2014-01-01

175

Understanding the etiology and management of HIV-associated peripheral neuropathy.  

PubMed

HIV may cause several forms of peripheral neuropathy, the most common of which is distal symmetric polyneuropathy (DSP) characterized by pain and sensory deficits in a stocking-glove distribution. The pathophysiology of DSP remains largely unknown but is thought to be related both to the neurotoxicity of HIV-through indirect immunomodulatory mechanisms-and to the neurotoxic effects of anti-retroviral therapies, most notably the dideoxynucleoside reverse transcription inhibitors or so-called d-drugs. Determining whether symptoms arise from the virus or the treatment poses a challenge to the clinician who must decide if a patient's HAART regimen should be altered. Treatment of symptoms related to HIV-DSP is a difficult task and there is no evidence that the traditional agents used in chronic neuropathic pain are efficacious in the HIV-DSP population. Indeed few pharmacologic agents have proven efficacy in HIV-DSP - these include cannabis and the capsaicin 8 % dermal patch. As such, alternative, non-pharmacologic therapies are being investigated. More research is needed to further elucidate the complex pathophysiology of HIV-DSP which may yield additional therapies for these patients. PMID:24969360

Stavros, Kara; Simpson, David M

2014-09-01

176

HIV-Associated Prospective Memory Impairment in the Laboratory Predicts Failures on a Semi-Naturalistic Measure of Health Care Compliance  

Microsoft Academic Search

HIV-associated neurocognitive impairment, particularly in the domain of prospective memory (ProM), increases the risk of poor everyday functioning outcomes, including medication non-adherence. However, whether ProM plays a role in health care compliance outside of the realm of medication adherence remains to be determined. This study evaluated the hypothesis that ProM is an independent predictor of failure to comply with non-medication-related

Jennifer B. Zogg; Steven Paul Woods; Erica Weber; Jennifer E. Iudicello; Matthew S. Dawson; Igor Grant

2010-01-01

177

Homelessness and HIV-Associated Risk Behavior Among African American Men Who Inject Drugs and Reside in the Urban South of the United States  

Microsoft Academic Search

This study determined whether homeless injection drug users (IDUs) were more likely than stably housed IDUs to engage in HIV-associated\\u000a risk behaviors. Respondent driven sampling was used to recruit 343 African American male IDUs. About 69% of men had been homeless\\u000a in the past year and 13% were HIV positive. Controlling for age and income, homeless men as compared to

Laura F. Salazar; Richard A. Crosby; David R. Holtgrave; Sara Head; Benjamin Hadsock; Jeffrey Todd; R. Luke Shouse

2007-01-01

178

A Degenerative Retinal Process in HIV-Associated Non-Infectious Retinopathy  

PubMed Central

HIV retinopathy is the most common non-infectious complication in the eyes of HIV-positive individuals. Oncotic lesions in the retinal nerve fiber layer, referred to as cotton wool spots (CWS), and intraretinal (IR) hemorrhages are frequently observed but are not unique to this pathology. HIV-positive patients have impaired color vision and contrast sensitivity, which worsens with age. Evidence of inner–retinal lesions and damage have been documented ophthalmoscopically, however their long term structural effect has not been investigated. It has been hypothesized that they may be partially responsible for loss of visual function and visual field. In this study we utilized clinical data, retinal imaging and transcriptomics approaches to comprehensively interrogate non-infectious HIV retinopathy. The methods employed encompassed clinical examinations, fundus photography, indirect ophthalmoscopy, Farmsworth-Munsell 100 hue discrimination testing and Illumina BeadChip analyses. Here we show that changes in the outer retina, specifically in the retinal pigment epithelium (RPE) and photoreceptor outer segments (POS) contribute to vision changes in non-infectious HIV retinopathy. We find that in HIV-positive retinae there is an induction of rhodopsin and other transcripts (including PDE6A, PDE6B, PDE6G, CNGA1, CNGB1, CRX, NRL) involved in visual transduction, as well as structural components of the rod photoreceptors (ABCA4 and ROM1). This is consistent with an increased rate of renewal of rod outer segments induced via increased phagocytosis by HIV-infected RPE previously reported in culture. Cone-specific transcripts (OPN1SW, OPN1LW, PDE6C, PDE6H and GRK7) are uniformly downregulated in HIV positive retina, likely due to a partial loss of cone photoreceptors. Active cotton wool spots and intraretinal hemorrhages (IRH) may not affect photoreceptors directly and the interaction of photoreceptors with the aging RPE may be the key to the progressive vision changes in HIV-positive patients. PMID:24069333

Freeman, William R.; Sprague, L. James; Gomez, Maria Laura; Cheng, Lingyun; El-Emam, Sharif; Mojana, Francesca; Bartsch, Dirk-Uwe; Bosten, Jenny; Ayyagari, Radha; Hardiman, Gary

2013-01-01

179

Sensory, psychological, and metabolic dysfunction in HIV-associated peripheral neuropathy: A cross-sectional deep profiling study.  

PubMed

HIV-associated sensory neuropathy (HIV-SN) is a frequent complication of HIV infection and a major source of morbidity. A cross-sectional deep profiling study examining HIV-SN was conducted in people living with HIV in a high resource setting using a battery of measures which included the following: parameters of pain and sensory symptoms (7day pain diary, Neuropathic Pain Symptom Inventory [NPSI] and Brief Pain Inventory [BPI]), sensory innervation (structured neurological examination, quantitative sensory testing [QST] and intraepidermal nerve fibre density [IENFD]), psychological state (Pain Anxiety Symptoms Scale-20 [PASS-20], Depression Anxiety and Positive Outlook Scale [DAPOS], and Pain Catastrophizing Scale [PCS], insomnia (Insomnia Severity Index [ISI]), and quality of life (Short Form (36) Health Survey [SF-36]). The diagnostic utility of the Brief Peripheral Neuropathy Screen (BPNS), Utah Early Neuropathy Scale (UENS), and Toronto Clinical Scoring System (TCSS) were evaluated. Thirty-six healthy volunteers and 66 HIV infected participants were recruited. A novel triumvirate case definition for HIV-SN was used that required 2 out of 3 of the following: 2 or more abnormal QST findings, reduced IENFD, and signs of a peripheral neuropathy on a structured neurological examination. Of those with HIV, 42% fulfilled the case definition for HIV-SN (n=28), of whom 75% (n=21) reported pain. The most frequent QST abnormalities in HIV-SN were loss of function in mechanical and vibration detection. Structured clinical examination was superior to QST or IENFD in HIV-SN diagnosis. HIV-SN participants had higher plasma triglyceride, concentrations depression, anxiety and catastrophizing scores, and prevalence of insomnia than HIV participants without HIV-SN. PMID:24973717

Phillips, Tudor J C; Brown, Matthew; Ramirez, Juan D; Perkins, James; Woldeamanuel, Yohannes W; Williams, Amanda C de C; Orengo, Christine; Bennett, David L H; Bodi, Istvan; Cox, Sarah; Maier, Christoph; Krumova, Elena K; Rice, Andrew S C

2014-09-01

180

Concurrent Classification Accuracy of the HIV Dementia Scale for HIV-associated Neurocognitive Disorders in the CHARTER Cohort  

PubMed Central

Background The HIV Dementia Scale (HDS) was developed to screen for HIV-associated Neurocognitive Disorders (HAND), but concerns have persisted regarding its substandard sensitivity. This study aimed to examine the classification accuracy of the HDS using raw and norm-based cutpoints, and to evaluate the contribution of the HDS subtests to predicting HAND. Methods 1,580 HIV-infected participants from 6 U.S. sites completed the HDS, and a gold standard neuropsychological battery, on which 51% of participants were impaired. Results: Sensitivity and specificity to HAND using the standard raw HDS cutpoint were 24% and 92%, respectively. The raw HDS subtests of attention, recall, and psychomotor speed significantly contributed to classification of HAND, while visuomotor construction contributed the least. A modified raw cutpoint of 14 yielded sensitivity of 66% and specificity of 61%, with cross-validation. Using norms also significantly improved sensitivity to 69% with a concomitant reduction of specificity to 56%, while the positive predictive value declined from 75% to 62% and negative predictive value improved from 54% to 64%. The HDS showed similarly modest rates of sensitivity and specificity among subpopulations of individuals with minimal comorbidity and successful viral suppression. Conclusions Findings indicate that while the HDS is a statistically significant predictor of HAND, particularly when adjusted for demographic factors, its relatively low diagnostic classification accuracy continues to hinder its clinical utility. A raw cutpoint of 14 greatly improved the sensitivity of the previously established raw cutscore, but may be subject to ceiling effects, particularly on repeat assessments. PMID:23111573

Sakamoto, Maiko; Marcotte, Thomas D.; Umlauf, Anya; Franklin, Donald; Heaton, Robert K.; Ellis, Ronald J.; Letendre, Scott; Alexander, Terry; McCutchan, J. Allen; Morgan, Erin E.; Woods, Steven Paul; Collier, Ann C.; Marra, Christina M.; Clifford, David B.; Gelman, Benjamin B.; McArthur, Justin C.; Morgello, Susan; Simpson, David; Grant, Igor

2012-01-01

181

Incidence of HIV-Associated Tuberculosis among Individuals Taking Combination Antiretroviral Therapy: A Systematic Review and Meta-Analysis  

PubMed Central

Background Knowledge of tuberculosis incidence and associated factors is required for the development and evaluation of strategies to reduce the burden of HIV-associated tuberculosis. Methods Systematic literature review and meta-analysis of tuberculosis incidence rates among HIV-infected individuals taking combination antiretroviral therapy. Results From PubMed, EMBASE and Global Index Medicus databases, 42 papers describing 43 cohorts (32 from high/intermediate and 11 from low tuberculosis burden settings) were included in the qualitative review and 33 in the quantitative review. Cohorts from high/intermediate burden settings were smaller in size, had lower median CD4 cell counts at study entry and fewer person-years of follow up. Tuberculosis incidence rates were higher in studies from Sub-Saharan Africa and from World Bank low/middle income countries. Tuberculosis incidence rates decreased with increasing CD4 count at study entry and duration on combination antiretroviral therapy. Summary estimates of tuberculosis incidence among individuals on combination antiretroviral therapy were higher for cohorts from high/intermediate burden settings compared to those from the low tuberculosis burden settings (4.17 per 100 person-years [95% Confidence Interval (CI) 3.39–5.14 per 100 person-years] vs. 0.4 per 100 person-years [95% CI 0.23–0.69 per 100 person-years]) with significant heterogeneity observed between the studies. Conclusions Tuberculosis incidence rates were high among individuals on combination antiretroviral therapy in high/intermediate burden settings. Interventions to prevent tuberculosis in this population should address geographical, socioeconomic and individual factors such as low CD4 counts and prior history of tuberculosis. PMID:25393281

Kufa, Tendesayi; Mabuto, Tonderai; Muchiri, Evans; Charalambous, Salome; Rosillon, Dominique; Churchyard, Gavin; Harris, Rebecca C.

2014-01-01

182

Excess Soluble CD40L Contributes to Blood Brain Barrier Permeability In Vivo: Implications for HIV-Associated Neurocognitive Disorders  

PubMed Central

Despite the use of anti-retroviral therapies, a majority of HIV-infected individuals still develop HIV-Associated Neurocognitive Disorders (HAND), indicating that host inflammatory mediators, in addition to viral proteins, may be contributing to these disorders. Consistently, we have previously shown that levels of the inflammatory mediator soluble CD40L (sCD40L) are elevated in the circulation of HIV-infected, cognitively impaired individuals as compared to their infected, non-impaired counterparts. Recent studies from our group suggest a role for the CD40/CD40L dyad in blood brain barrier (BBB) permeability and interestingly, sCD40L is thought to regulate BBB permeability in other inflammatory disorders of the CNS. Using complementary multiphoton microscopy and quantitative analyses in wild-type and CD40L deficient mice, we now reveal that the HIV transactivator of transcription (Tat) can induce BBB permeability in a CD40L-dependent manner. This permeability of the BBB was found to be the result of aberrant platelet activation induced by Tat, since depletion of platelets prior to treatment reversed Tat-induced BBB permeability. Furthermore, Tat treatment led to an increase in granulocyte antigen 1 (Gr1) positive monocytes, indicating an expansion of the inflammatory subset of cells in these mice, which were found to adhere more readily to the brain microvasculature in Tat treated animals. Exploring the mechanisms by which the BBB becomes compromised during HIV infection has the potential to reveal novel therapeutic targets, thereby aiding in the development of adjunct therapies for the management of HAND, which are currently lacking. PMID:23251626

Davidson, Donna C.; Hirschman, Michael P.; Sun, Anita; Singh, Meera V.; Kasischke, Karl; Maggirwar, Sanjay B.

2012-01-01

183

CCR2 on CD14+CD16+ monocytes is a biomarker of HIV-associated neurocognitive disorders  

PubMed Central

Objective: To evaluate C-C chemokine receptor type 2 (CCR2) on monocyte subsets as a prognostic peripheral blood biomarker of HIV-associated neurocognitive disorders (HAND). Methods: We characterized monocyte populations in HIV-infected individuals with and without HAND from 2 cohorts and assessed their transmigration across an in vitro model of the human blood-brain barrier (BBB). We examined CCR2 expression among the monocyte populations as a prognostic/predictive biomarker of HAND and its functional consequences in facilitating monocyte diapedesis. Results: We determined that CCR2 was significantly increased on CD14+CD16+ monocytes in individuals with HAND compared to infected people with normal cognition. CCR2 remained elevated irrespective of the severity of cognitive impairment, combined antiretroviral therapy status, viral load, and current or nadir CD4 T-cell count. There was no association between CCR2 on other monocyte populations and HAND. There was a functional consequence to the increase in CCR2, as CD14+CD16+ monocytes from individuals with HAND transmigrated across our model of the human BBB in significantly higher numbers in response to its ligand chemokine (C-C) motif ligand 2 (CCL2) compared to the cell migration that occurred in people with no cognitive deficits. It should be noted that our study had the limitation of a smaller sample size of unimpaired individuals. In contrast, there was no difference in the transmigration of other monocyte subsets across the BBB in response to CCL2 in seropositive individuals with or without HAND. Conclusions: Our findings indicate CCR2 on CD14+CD16+ monocytes is a novel peripheral blood biomarker of HAND. PMID:25340088

Williams, Dionna W.; Byrd, Desiree; Rubin, Leah H.; Anastos, Kathryn; Morgello, Susan

2014-01-01

184

MOON: MapReduce On Opportunistic eNvironments Virginia Tech  

E-print Network

MOON: MapReduce On Opportunistic eNvironments Heshan Lin Virginia Tech hlin2@cs.vt.edu Xiaosong Ma this, we propose MOON, short for MapReduce On Opportunistic eNvironments. MOON extends Hadoop, an open, demonstrate that MOON can deliver a three-fold performance improvement to Hadoop in volatile, volunteer

Ma, Xiaosong

185

Performance Evaluation of Opportunistic Round Robin Scheduling for V-BLAST Users over MIMO Channels  

E-print Network

and supported capacity at different number of users. Keywords: MIMO Scheduling, V-BLAST, Opportunistic RoundPerformance Evaluation of Opportunistic Round Robin Scheduling for V-BLAST Users over MIMO Channels uplink MIMO channels. Each user spatially multiplexes his data over multiple transmit antennas

Al-Ghadhban, Samir

186

On cognitive radio networks with opportunistic power control strategies in fading channels  

Microsoft Academic Search

In this paper, we consider a cognitive radio system in fading wireless channels and propose an opportunistic power control strategy for the cognitive users, which serves as an alternative way to protect the primary user's transmission and to realize spectrum sharing between the primary user and the cognitive users. The key feature of the proposed strategy is that, via opportunistically

Yan Chen; Guanding Yu; Zhaoyang Zhang; Hsiao-hwa Chen; Peiliang Qiu

2008-01-01

187

Poster Abstract: An Evaluation Study of Routing Reliability in Opportunistic Networks  

E-print Network

) if there are uncooperative peers in the network, such as free riders, black holes, and wormholes. This work was supportedPoster Abstract: An Evaluation Study of Routing Reliability in Opportunistic Networks Che}@iis.sinica.edu.tw ABSTRACT An opportunistic network is a type of challenged network that has attracted increasing attention

Chen, Ling-Jyh

188

Heterogeneous epidemic model for assessing data dissemination in opportunistic networks  

E-print Network

In this paper we investigate a susceptible-infected-susceptible (SIS) epidemic model describing data dissemination in opportunistic networks with heterogeneous setting of transmission parameters. We obtained the estimation of the final epidemic size assuming that amount of data transferred between network nodes possesses a Pareto distribution, implying scale-free properties. In this context, more heterogeneity in susceptibility means the less severe epidemic progression, and, on the contrary, more heterogeneity in infectivity leads to more severe epidemics -- assuming that the other parameter (either heterogeneity or susceptibility) stays fixed. The results are general enough and can be useful in general epidemic theory for estimating the epidemic progression for diseases with no significant acquired immunity -- in the cases where Pareto distribution holds.

Alexeev, Vadim; Temerev, Alexander

2014-01-01

189

HIV-Associated Tuberculosis  

PubMed Central

The intersecting HIV and Tuberculosis epidemics in countries with a high disease burden of both infections pose many challenges and opportunities. For patients infected with HIV in high TB burden countries, the diagnosis of TB, ARV drug choices in treating HIV-TB coinfected patients, when to initiate ARV treatment in relation to TB treatment, managing immune reconstitution, minimising risk of getting infected with TB and/or managing recurrent TB, minimizing airborne transmission, and infection control are key issues. In addition, given the disproportionate burden of HIV in women in these settings, sexual reproductive health issues and particular high mortality rates associated with TB during pregnancy are important. The scaleup and resource allocation to access antiretroviral treatment in these high HIV and TB settings provide a unique opportunity to strengthen both services and impact positively in meeting Millennium Development Goal 6. PMID:20871843

Naidoo, Kogieleum; Naidoo, Kasavan; Padayatchi, Nesri; Abdool Karim, Quarraisha

2011-01-01

190

Evidence of cryptic individual specialization in an opportunistic insectivorous bat  

USGS Publications Warehouse

Habitat use and feeding behaviors of cryptic animals are often poorly understood. Analyses of stable isotope ratios in animal body tissues can help reveal an individual's location and resource use during tissue growth. We investigated variation in stable isotope ratios of 4 elements (H, C, N, and S) in the hair of a sedentary species of insectivorous bat (Eptesicus fuscus) inhabiting a chemically complex urban landscape. Our objective was to quantify population-level isotopic variation and test for evidence of resource specialization by individuals. Bats were sampled over 3 annual molt cycles at maternity roosts in buildings and variance components analysis was used to test whether intraindividual isotopic variation among molts differed from interindividual variation, after controlling for year and roost-group effects. Consistent with prior evidence that E. fuscus is opportunistic in its habitat use and foraging at the population level, we observed wide population-level variation for all isotopes. This variation likely reflects the chemical complexity of the urban landscape studied. However, isotopic variation among years within marked individuals was lower than variation among marked individuals within year for all isotopes, and carbon signatures indicated resource specialization by roost groups and individuals. This is the 1st study to examine variation in stable isotope ratios of individual wild bats over multiple years. Although our results suggest this population tends toward opportunistic habitat use or prey selection, or both, during molt periods, results also indicate that individuals and groups of bats composing the population might be habitat or dietary specialists—a novel finding for insectivorous bats.

Cryan, Paul M.; Stricker, Craig A.; Wunder, Michael B.

2012-01-01

191

Cytoplasmic HIV-RNA in monocytes determines microglial activation and neuronal cell death in HIV-associated neurodegeneration.  

PubMed

Despite highly active antiretroviral therapy, HIV-associated neurocognitive disorders (HAND) are still highly prevalent. Direct neurotoxicity of microglia activated by HIV-infected monocytes independent from viral replication may account for this observation. To investigate underlying molecular and viral determinants, human monocytoid cells (U937) transduced with HIV-particles were co-cultured with primary human microglia or astrocytes. Using genetically-engineered HIV-particles key steps of infection were examined. Levels of pro-inflammatory/neurotoxic cytokines were investigated in co-culture supernatants by flow cytometry. Neurotoxicity mediated by the supernatants was analysed using primary cortical rat neurons. To corroborate our findings, cytokine profiles in cerebrospinal fluid (CSF) of neuropsychologically asymptomatic HIV positive (HIV(+)) patients (n=45) were correlated with neurofilament H (NfH) as surrogate of neuronal/axonal degeneration. In contrast to direct exposure of HIV to microglia, only the presence of HIV-transduced monocytoid cells strongly activated human microglia as evidenced by enhanced secretion of CXCL10, CCL5, CCL2, and IL-6 (1.3-7.1-fold; p<0.01) leading to two-fold increased neurotoxicity (p<0.001). In direct comparison, astrocyte activation by HIV-transduced monocytoid cells was limited. Using different mutant HIV-particles we show that the presence of cytoplasmic HIV-RNA in monocytoid cells is the viral determinant for this unique microglial activation pattern and subsequent neuronal cell death; reverse transcription and expression of viral genes were not essential. In CSF of presymptomatic HIV(+) patients, CXCL10, CCL5 and IL-6 were correlated with NfH as surrogate marker of neurodegeneration as well as CSF-pleocytosis. In conclusion, cytosolic viral RNA in monocytes is mandatory for subsequent microglial activation and neurotoxicity; activated astrocytes may augment neuroinflammation. In addition, neuroinflammation and neurodegeneration occur even in preclinical HIV(+) patients and are associated with cytokines regulated in vitro. Our data may aid in the development of biomarkers and glia-directed therapeutic approaches of HAND. PMID:25150097

Faissner, Simon; Ambrosius, Björn; Schanzmann, Kirsten; Grewe, Bastian; Potthoff, Anja; Münch, Jan; Sure, Ulrich; Gramberg, Thomas; Wittmann, Sabine; Brockmeyer, Norbert; Uberla, Klaus; Gold, Ralf; Grunwald, Thomas; Chan, Andrew

2014-11-01

192

Developing Clinical Strength-of-Evidence Approach to Define HIV-Associated Malignancies for Cancer Registration in Kenya  

PubMed Central

Background Sub-Saharan Africa cancer registries are beset by an increasing cancer burden further exacerbated by the AIDS epidemic where there are limited capabilities for cancer-AIDS match co-registration. We undertook a pilot study based on a “strength-of-evidence” approach using clinical data that is abstracted at the time of cancer registration for purposes of linking cancer diagnosis to AIDS diagnosis. Methods/Findings The standard Nairobi Cancer Registry form was modified for registrars to abstract the following clinical data from medical records regarding HIV infection/AIDS in a hierarchal approach at time of cancer registration from highest-to-lowest strength-of-evidence: 1) documentation of positive HIV serology; 2) antiretroviral drug prescription; 3) CD4+ lymphocyte count; and 4) WHO HIV clinical stage or immune suppression syndrome (ISS), which is Kenyan terminology for AIDS. Between August 1 and October 31, 2011 a total of 1,200 cancer cases were registered. Of these, 171 cases (14.3%) met clinical strength-of-evidence criteria for association with HIV infection/AIDS; 69% (118 cases were tumor types with known HIV association – Kaposi’s sarcoma, cervical cancer, non-Hodgkin’s and Hodgkin’s lymphoma, and conjunctiva carcinoma) and 31% (53) were consistent with non-AIDS defining cancers. Verifiable positive HIV serology was identified in 47 (27%) cases for an absolute seroprevalence rate of 4% among the cancer registered cases with an upper boundary of 14% among those meeting at least one of strength-of-evidence criteria. Conclusions/Significance This pilot demonstration of a hierarchal, clinical strength-of-evidence approach for cancer-AIDS registration in Kenya establishes feasibility, is readily adaptable, pragmatic, and does not require additional resources for critically under staffed cancer registries. Cancer is an emerging public health challenge, and African nations need to develop well designed population-based studies in order to better define the impact and spectrum of malignant disease in the backdrop of HIV infection. PMID:24465764

Moats, Pamela; Gurka, Matthew J.; Mutuma, Geoffrey; Metheny, Christine; Mwamba, Peter M.; Oyiro, Peter O.; Fisher, Melanie; Ayers, Leona W.; Rochford, Rosemary; Mwanda, Walter O.; Remick, Scot C.

2014-01-01

193

Tonic Activation of Brain GnRH Immunoreactivity despite Reduction of Peripheral Reproductive Parameters in Opportunistically Breeding Zebra Finches  

Microsoft Academic Search

Opportunistically breeding species offer the unique opportunity to understand mechanisms in reproductive physiology that allow for extreme flexibility in the regulation of reproduction. We studied a well-known opportunistic breeder, the zebra finch (Taeniopygia guttata) to test the hypothesis that the reproductive axis of opportunists is in a constant state of ‘near-readiness’. In wild zebra finches, reproduction is highly correlated with

Nicole Perfito; George Bentley; Michaela Hau

2006-01-01

194

The opportunistic transmission of wireless worms between mobile devices  

NASA Astrophysics Data System (ADS)

The ubiquity of portable wireless-enabled computing and communications devices has stimulated the emergence of malicious codes (wireless worms) that are capable of spreading between spatially proximal devices. The potential exists for worms to be opportunistically transmitted between devices as they move around, so human mobility patterns will have an impact on epidemic spread. The scenario we address in this paper is proximity attacks from fleetingly in-contact wireless devices with short-range communication range, such as Bluetooth-enabled smart phones. An individual-based model of mobile devices is introduced and the effect of population characteristics and device behaviour on the outbreak dynamics is investigated. The model uses straight-line motion to achieve population, though it is recognised that this is a highly simplified representation of human mobility patterns. We show that the contact rate can be derived from the underlying mobility model and, through extensive simulation, that mass-action epidemic models remain applicable to worm spreading in the low density regime studied here. The model gives useful analytical expressions against which more refined simulations of worm spread can be developed and tested.

Rhodes, C. J.; Nekovee, M.

2008-12-01

195

Opportunistic use of cognitive smokescreens by araneophagic jumping spiders.  

PubMed

Little is known about how a prey species' cognitive limitations might shape a predator's prey-capture strategy. A specific hypothesis is investigated: predators take advantage of times when the prey's attention is focussed on its own prey. Portia fimbriata, an araneophagic jumping spider (Salticidae) from Queensland, is shown in a series of 11 experiments to exploit opportunistically a situation in which a web-building spider on which it preys, Zosis genicularis (Uloboridae), is preoccupied with wrapping up its own prey. Experimental evidence supports three conclusions: (1). while relying on optical cues alone, P. fimbriata perceives when Z. genicularis is wrapping up prey; (2). when busy wrapping up prey, the responsiveness of Z. genicularis to cues from potential predators is diminished; and (3). P. fimbriata moves primarily during intervals when Z. genicularis is busy wrapping up prey. P. fimbriata's strategy is effective partly because the wrapping behaviour of Z. genicularis masks the web signals generated by the advancing P. fimbriata's footsteps and also because, while wrapping, Z. genicularis' attention is diverted away from predator-revealing cues. PMID:12357287

Jackson, Robert R; Pollard, Simon D; Cerveira, Ana M

2002-09-01

196

Opportunistic pathogens relative to physicochemical factors in water storage tanks.  

PubMed

Household water in Oman, as well as in other countries in the region, is stored in tanks placed on house roofs that can be subjected to physicochemical factors which can promote microbial growth, including pathogens and opportunistic pathogens which pose health risks. Water samples were collected from 30 houses in a heavily populated suburb of Muscat. The tanks used were either glass reinforced plastic (GRP), polyethylene or galvanised iron (GI). Heterotrophic bacteria, coliforms, faecal coliforms and iron sulphur bacteria varied significantly in the three tanks. Yeast and mould count showed significant variations. Isolation of Aeromonas spp., fluorogenic and pathogenic Pseudomonas, Pasteurella, Salmonella, Serratia and Tatumella, and Yersinia and Legionella in biofilms varied in the three tanks. The fungi isolates in the three tanks were Penicillium, Cladosporium and Aspergillus. Nephelometric turbidity unit, threshold odour number and free chlorine varied significantly in the three tanks. True colour unit values did not show a significant difference; however, GRP tanks had algae, autotrophic and pigmented microorganisms. In addition, GI tanks had sediments and corrosion. The results of this investigation are important to evaluate the status of the present household water tanks in countries with high annual temperatures, which may affect public health. PMID:21942202

Al-Bahry, S N; Elshafie, A E; Victor, R; Mahmoud, I Y; Al-Hinai, J A

2011-06-01

197

Robust and Opportunistic Autonomous Science for a Potential Titan Aerobot  

NASA Technical Reports Server (NTRS)

We are developing onboard planning and execution technologies to provide robust and opportunistic mission operations for a potential Titan aerobot. Aerobot have the potential for collecting a vast amount of high priority science data. However, to be effective, an aerobot must address several challenges including communication constraints, extended periods without contact with Earth, uncertain and changing environmental conditions, maneuverability constraints and potentially short-lived science opportunities. We are developing the AerOASIS system to develop and test technology to support autonomous science operations for a potential Titan Aerobot. The planning and execution component of AerOASIS is able to generate mission operations plans that achieve science and engineering objectives while respecting mission and resource constraints as well as adapting the plan to respond to new science opportunities. Our technology leverages prior work on the OASIS system for autonomous rover exploration. In this paper we describe how the OASIS planning component was adapted to address the unique challenges of a Titan Aerobot and we describe a field demonstration of the system with the JPL prototype aerobot.

Gaines, Daniel M.; Estlin, Tara; Schaffer, Steve; Castano, Rebecca; Elfes, Alberto

2010-01-01

198

Invasive genotypes are opportunistic specialists not general purpose genotypes  

PubMed Central

It is not clear which forms of plasticity in fitness-related traits are associated with invasive species. On one hand, it may be better to have a robust performance across environments. On the other, it may be beneficial to take advantage of limited favorable conditions. We chose to study a worldwide invasive species, Potamopyrgus antipodarum, and compare the plasticity of life-history traits of a sample of invasive genotypes to a sample of ancestral-range genotypes. We examined the responses to salinity in this freshwater snail because it varies spatially and temporally in the introduced range and contributes to variation in fitness in our system. We used a recently developed statistical method that quantifies aspects of differences in the shape among reaction norms. We found that the invasive lineages survived and reproduced with an increased probability at the higher salinities, and were superior to ancestral-range lineages in only two traits related to reproduction. Moreover, we found that in terms of traits related to growth, the invasive lineages have a performance optimum that is shifted to higher salinities than the ancestral-range lineages as well as having a narrower niche breadth. Contrary to the prediction of the general purpose genotype hypothesis, we found that invasive lineages tended to be opportunistic specialists.

Drown, Devin M; Levri, Edward P; Dybdahl, Mark F

2011-01-01

199

Experience and challenges presented by a multicenter crossover study of combination analgesic therapy for the treatment of painful HIV-associated polyneuropathies  

PubMed Central

Objective There is limited evidence for efficacy of analgesics as monotherapy for neuropathic pain associated with HIV-associated polyneuropathies, in spite of demonstrated efficacy in other neuropathic pain conditions. We evaluated the tolerability and analgesic efficacy of duloxetine, methadone, and the combination of duloxetine-methadone compared to placebo. Design This study was a phase II, randomized, double blind, placebo-controlled, four-period crossover multi-center study of analgesic therapy for patients with at least moderate neuropathic pain due to HIV-associated polyneuropathy. Duloxetine, methadone, combination duloxetine-methadone, and placebo were administered in four different possible sequences. The primary outcome measure was mean pain intensity (MPI) measured daily in a study-supplied pain diary. Results A total of 15 patients were enrolled from 8 study sites and 8 patients completed the entire trial. Study treatments failed to show statistically significant change in MPI compared to placebo. Adverse events were frequent and associated with high rates of drug discontinuation and study drop-out. Conclusions Challenges with participant recruitment and poor retention precluded trial completion to its planned targets, limiting our evaluation of the analgesic efficacy of the study treatments. Challenges to successful completion of this study and lessons learned are discussed. PMID:23565581

Harrison, Taylor; Miyahara, Sachiko; Lee, Anthony; Evans, Scott; Bastow, Barbara; Simpson, David; Gilron, Ian; Dworkin, Robert; Daar, Eric S.; Wieclaw, Linda; Clifford, David B.

2014-01-01

200

The oxidative stress response of the opportunistic fungal pathogen Candida glabrata.  

PubMed

Organisms have evolved different strategies to respond to oxidative stress generated as a by-product of aerobic respiration and thus maintain the redox homeostasis within the cell. In particular, fungal pathogens are exposed to reactive oxygen species (ROS) when they interact with the phagocytic cells of the host which are the first line of defense against fungal infections. These pathogens have co-opted the enzymatic (catalases, superoxide dismutases (SODs), and peroxidases) and non-enzymatic (glutathione) mechanisms used to maintain the redox homeostasis within the cell, to resist oxidative stress and ensure survival within the host. Several virulence factors have been related to the response to oxidative stress in pathogenic fungi. The opportunistic fungal pathogen Candida glabrata (C. glabrata) is the second most common cause of candidiasis after Candida albicans (C. albicans). C. glabrata has a well defined oxidative stress response (OSR), which include both enzymatic and non-enzymatic mechanisms. C. glabrata OSR is controlled by the well-conserved transcription factors Yap1, Skn7, Msn2 and Msn4. In this review, we describe the OSR of C. glabrata, what is known about its core elements, its regulation and how C. glabrata interacts with the host. This manuscript is part of the series of works presented at the "V International Workshop: Molecular genetic approaches to the study of human pathogenic fungi" (Oaxaca, Mexico, 2012). PMID:24270068

Briones-Martin-Del-Campo, Marcela; Orta-Zavalza, Emmanuel; Juarez-Cepeda, Jacqueline; Gutierrez-Escobedo, Guadalupe; Cañas-Villamar, Israel; Castaño, Irene; De Las Peñas, Alejandro

2014-01-01

201

15-lipoxygenase carries a secretable arachidonatePseudomonas aeruginosaThe opportunistic pathogen  

E-print Network

and liquid chromatography-UV-tandem mass spectrometry (LC-UV-MS-MS), we demonstrate that PA1169 encodes resistance to antibiotics and for its ability to cause a wide spectrum of opportunistic infections (1). P

Mekalanos, John

202

OPPORTUNISTIC ASPERGILLUS PATHOGENS MEASURED IN HOME AND HOSPITAL TAP WATER BY MOLD SPECIFIC QUANTITATIVE PCR (MSQPCR)  

EPA Science Inventory

Opportunistic fungal pathogens are a concern because of the increasing number of immunocompromised patients. The goal of this research was to test a simple extraction method and rapid quantitative PCR (QPCR) measurement of the occurrence of potential pathogens, Aspergillus fumiga...

203

AN ECOLOGICAL ASSESSMENT OF OPPORTUNISTIC PLANT SPECIES IN GREAT LAKES COASTAL WETLANDS USING AIRBORNE HYPERSPECTRAL DATE  

EPA Science Inventory

Airbome hyperspectral data were used to detect dense patches of Phragmites australis, a native opportunist plant species, at the Pointe Mouillee coastal wetland complex (Wayne and Monroe Counties, Michigan). This study provides initial results from one of thirteen coastal wetland...

204

ACCURACY ASSESSMENTS OF AIRBORNE HYSPERSPECTRAL DATA FOR MAPPING OPPORTUNISTIC PLANT SPECIES IN FRESHWATER COASTAL WETLANDS  

EPA Science Inventory

Airbome hyperspectral data were used to detect dense patches of Phragmites australis, a native opportunist plant species, at the Pointe Mouillee coastal wetland complex (Wayne and Monroe Counties, Michigan). This study provides initial results from one of thirteen coastal wetland...

205

Creating complex, adaptable management strategies via the opportunistic integration of decentralised management resources  

E-print Network

information, diagnosing problems and providing solutions while avoiding conflicting management plansCreating complex, adaptable management strategies via the opportunistic integration of decentralised management resources Abstract The ambitious goals of autonomic management require complex

Diaconescu, Ada

206

The Pseudomonas aeruginosa opportunistic pathogen and human infections.  

PubMed

Pseudomonas aeruginosa, a Gram-negative environmental species and an opportunistic microorganism, establishes itself in vulnerable patients, such as those with cystic fibrosis or hospitalized in intensive care units. It has become a major cause of nosocomial infections worldwide (about 10% of all such infections in most European Union hospitals) and a serious threat to Public Health. The overuse and misuse of antibiotics have also led to the selection of resistant strains against which very few therapeutic options exist. How an environmental species can cause human infections remains a key question that still needs elucidation despite the incredibly high progress that has been made in the P. aeruginosa biology over the past decades. The workshop belonging to Current trends in Biomedicine series, which was held under the sponsorship of the Universidad International de Andalucia between the 8th and the 10th November 2010 brought in the most recent advances in the environmental life of P. aeruginosa, the human P. aeruginosa infections, the new animal models to study Pseudomonas infections, the new genetic aspects including metabolomics, genomics and bioinformatics and the community lifestyle named biofilm that accounts for P. aeruginosa persistence in humans. This workshop organized by Soeren Molin (Danemark), Juan-Luis Ramos (Spain) and Sophie de Bentzmann (France) gathered 46 researchers coming from 11 European and American countries in a small format and was hosted in the 'Sede Antonio Machado' in Baeza. It was organized in seven sessions covering animal models for P. aeruginosa pathogenesis, resistance to drugs, regulatory potency including small RNA, two component systems, extracytoplasmic function sigma factors and trancriptional regulators, new therapies emerging from dissection of molecular mechanisms, and evolutionary mechanisms of P. aeruginosa strains in patients. PMID:21450006

de Bentzmann, Sophie; Plésiat, Patrick

2011-07-01

207

Opportunistic and Other Infections in HIV-Infected Children in Latin America Compared to a Similar Cohort in the United States  

PubMed Central

Abstract Opportunistic and other infections have declined since the introduction of highly active antiretroviral therapy (HAART) in developed countries but few studies have addressed the impact of HAART in HIV-infected children from developing countries. This study examines the prevalence and incidence of opportunistic and other infections in Latin America during the HAART era. Vertically HIV-infected children enrolled in a cohort study between 2002 and 2007 were followed for the occurrence of 29 targeted infections. Cross-sectional and longitudinal analyses were performed to calculate the prevalence of infections before enrollment and the incidence rates of opportunistic and other infections after enrollment. Comparisons were made with data from a U.S. cohort (PACTG 219C). Of the 731 vertically HIV-infected children 568 (78%) had at least one opportunistic or other infection prior to enrollment. The most prevalent infections were bacterial pneumonia, oral candidiasis, varicella, tuberculosis, herpes zoster, and Pneumocystis jiroveci pneumonia. After enrollment, the overall incidence was 23.5 per 100 person-years; the most common infections (per 100 person-years) were bacterial pneumonia (7.8), varicella (3.0), dermatophyte infections (2.9), herpes simplex (2.5), and herpes zoster (1.8). All of these incidence rates were higher than those reported in PACTG 219C. The types and relative distribution of infections among HIV-infected children in Latin America in this study are similar to those seen in the United States but the incidence rates are higher. Further research is necessary to determine the reasons for these higher rates. PMID:21902581

Alarcón, Jorge O.; Freimanis-Hance, Laura; Krauss, Margot; Reyes, Mary F.; Cardoso, Claudete Aparecida Araújo; Mussi-Pinhata, Marisa M.; Cardoso, Edmundo

2012-01-01

208

Use of traditional medicines in the management of HIV/AIDS opportunistic infections in Tanzania: a case in the Bukoba rural district  

PubMed Central

Background Ethnobotanical surveys were carried out to document herbal remedies used in the management of HIV/AIDS opportunistic infections in Bukoba Rural district, Tanzania. The district is currently an epicenter of HIV/AIDS and although over 90% of the population in the district relies on traditional medicines to manage the disease, this knowledge is impressionistic and not well documented. The HIV/AIDS opportunistic conditions considered during the study were Tuberculosis (TB), Herpes zoster (Shingles), Herpes simplex (Genital herpes), Oral candidiasis and Cryptococcal meningitis. Other symptomatic but undefined conditions considered were skin rashes and chronic diarrhea. Methods An open-ended semi-structured questionnaire was used in collecting field information. Descriptive statistics were used to analyze the ethnobotanical data collected. Factor of informant consensus (Fic) was used to analyze the ethnobotanical importance of the plants. Results In the present study, 75 plant species belonging to 66 genera and 41 families were found to be used to treat one or more HIV/AIDS related infections in the district. The study revealed that TB and oral candidiasis were the most common manifestations of HIV/AIDS opportunistic infections affecting most of the population in the area. It unveils the first detailed account of ethnomedical documentation of plants focusing the management of HIV/AIDS related infections in the district. Conclusion It is concluded that the ethnopharmacological information reported forms a basis for further research to identify and isolate bioactive constituents that can be developed to drugs for the management of the HIV/AIDS opportunistic infections. PMID:17623081

Kisangau, Daniel P; Lyaruu, Herbert VM; Hosea, Ken M; Joseph, Cosam C

2007-01-01

209

Common Wart  

MedlinePLUS

newsletter | contact Share | Common Wart A parent's guide to condition and treatment information A A A This image displays a large wart on ... over 100 types of the human papillomavirus (HPV). Common warts are usually found on areas of the ...

210

Mass Media as an HIV-Prevention Strategy: Using Culturally Sensitive Messages to Reduce HIV-Associated Sexual Behavior of At-Risk African American Youth  

PubMed Central

The evidence base and theoretical frameworks for mass media HIV-prevention campaigns in the United States are not well-developed. We describe an intervention approach using culturally sensitive mass media messages to enhance protective beliefs and behavior of African American adolescents at risk for HIV. This approach exploits the potential that mass media messages have, not only to reach a large segment of the adolescent population and thereby support normative change, but also to engage the most vulnerable segments of this audience to reduce HIV-associated risk behaviors. The results from an ongoing HIV-prevention trial implemented in 2 medium-sized cities in the United States illustrate the effectiveness of this intervention approach. PMID:19833995

Sznitman, Sharon; DiClemente, Ralph; Salazar, Laura F.; Vanable, Peter A.; Carey, Michael P.; Hennessy, Michael; Brown, Larry K.; Valois, Robert F.; Stanton, Bonita F.; Fortune, Thierry; Juzang, Ivan

2009-01-01

211

Common Cold  

MedlinePLUS

... nose, coughing - everyone knows the symptoms of the common cold. It is probably the most common illness. In the course of a year, people ... avoid colds. There is no cure for the common cold. For relief, try Getting plenty of rest ...

212

Preventing Opportunistic Infections in HIV (Beyond the Basics)  

MedlinePLUS

... more common in certain areas, such as the Mississippi, Ohio, and St. Lawrence River valleys, the Caribbean, southern Mexico, and certain parts of ... The most common type of coccidioidomycosis is a type of pneumonia known as Valley Fever. People who are infected with HIV are ...

213

Within-year differences in reproductive investment in laboratory zebra finches ( Taeniopygia guttata ), an opportunistically breeding bird  

Microsoft Academic Search

Reproduction in opportunistically breeding bird species has traditionally been considered non-seasonal with individuals taking\\u000a advantage of favourable environmental conditions as they arise. However, some studies imply that this opportunistic breeding\\u000a may be superimposed on an underlying seasonality, which has effects on the readiness to breed when conditions are favourable.\\u000a The zebra finch (Taeniopygia guttata) is the classic opportunistic breeder and

Kathryn Williamson; Lucy Gilbert; Alison N. Rutstein; Emma C. Pariser; Jeff A. Graves

2008-01-01

214

Clays, common  

USGS Publications Warehouse

Part of a special section on the state of industrial minerals in 1997. The state of the common clay industry worldwide for 1997 is discussed. Sales of common clay in the U.S. increased from 26.2 Mt in 1996 to an estimated 26.5 Mt in 1997. The amount of common clay and shale used to produce structural clay products in 1997 was estimated at 13.8 Mt.

Virta, R.L.

1998-01-01

215

"My body's a 50 year-old but my brain is definitely an 85 year-old": exploring the experiences of men ageing with HIV-associated neurocognitive challenges  

PubMed Central

Introduction Research investigating HIV, neurocognition and ageing is well developed using neuropsychometric or other quantitative approaches; however, little is known about individuals’ subjective experiences. The purpose of this article is to explore the experiences of men aged 50 and older who self-identify as having HIV-associated neurocognitive challenges. In particular, this study uses the Episodic Disability Framework (EDF) to explore participants’ perceptions regarding: 1) symptoms/impairments, difficulties with day-to-day activities, challenges with social inclusion and uncertainty; 2) ageing as related to their HIV-associated neurocognitive challenges, and 3) the episodic nature of their HIV-associated neurocognitive challenges. Methods This qualitative, interpretive study involved in-depth, semi-structured interviews with 12 men aged 50 years and older who self-identified as having HIV-associated neurocognitive challenges. Participants were recruited from a neurobehavioural research unit (NBRU) at a large hospital in Toronto, Canada. Data were analyzed thematically and with reference to the EDF. Results Participants’ experiences reflected all concepts within the EDF to some extent. Difficulties with daily activities were diverse but were addressed using similar living strategies. Participants described challenges with work and social relationships resulting from neurocognitive challenges. Participants downplayed the significance of uncertainty in their lives, which they attributed to effective living strategies. Most men reported confusion regarding the link between their neurocognitive challenges and ageing. Others discussed ageing as an asset that helped with coping. Conclusions This is the first study to use a disability framework to examine the subjective experiences of men ageing with HIV-associated neurocognitive challenges. Findings reframe the episodic disability experienced by these individuals as being predictably linked to certain triggers. As such, support for managing neurocognitive challenges could focus on triggers that exacerbate the condition in addition to the impairments themselves. The study also describes ageing as not only a source of problems but also as an asset among men growing older with HIV. PMID:23883539

Hopcroft, Lisa; Bester, Laura; Clement, Daniel; Quigley, Adria; Sachdeva, Manisha; Rourke, Sean B; Nixon, Stephanie A

2013-01-01

216

Common Wart  

MedlinePLUS

newsletter | contact Share | Common Wart Information for adults A A A This image displays an unusual "horseshoe-shaped" wart on chin. Overview Warts ... over 100 types of the human papillomavirus (HPV). Common warts are usually found on areas of the ...

217

Election Results and Opportunistic Policies: A New Test of the Rational Political Business Cycle Model  

E-print Network

;#1; + (1#0; #26;)#25; #0; b#26; #0; gL1;1 #1;#1; ; (14) which is the type-weighted ex ante probability that the incumbent is reelected. These two objects are jointly determined at equilibrium. On the one hand, the degree of signalling is a determinant... of ?scal policy. 12 model predicts that opportunistic behavior pays o¤ in the sense that the win-margin is (weakly) increasing in the size of the opportunistic distortion ( @h@OD #21; 0). Secondly, although the theory predicts that the win-margin is a...

Aidt, Toke S; Veiga, F J; Veiga, L G

218

Plumbing of hospital premises is a reservoir for opportunistically pathogenic microorganisms: a review.  

PubMed

Several bacterial species that are natural inhabitants of potable water distribution system biofilms are opportunistic pathogens important to sensitive patients in healthcare facilities. Waterborne healthcare-associated infections (HAI) may occur during the many uses of potable water in the healthcare environment. Prevention of infection is made more challenging by lack of data on infection rate and gaps in understanding of the ecology, virulence, and infectious dose of these opportunistic pathogens. Some healthcare facilities have been successful in reducing infections by following current water safety guidelines. This review describes several infections, and remediation steps that have been implemented to reduce waterborne HAIs. PMID:23327332

Williams, Margaret M; Armbruster, Catherine R; Arduino, Matthew J

2013-01-01

219

Finding Self-Similarities in Opportunistic People Networks  

E-print Network

network traces, and our contributions are the following: First, we identify the censorship issue, which is used in designing our proposed censorship removal algorithm (CRA) that is used to recover/reconnection is common, and/or link perfor- mance is highly variable or extreme. Therefore, traditional Internet

Ouhyoung, Ming

220

Common cold  

MedlinePLUS

... and before eating and preparing food. Disinfect your environment. Clean commonly touched surfaces (such as sink handles, ... system work properly. Eat yogurt that contains "active cultures." These may help prevent colds. Probiotics may help ...

221

In Vitro and In Vivo Effects of IGF-I on Adiposity in HIV-associated Metabolic Disease: A Pilot Study  

PubMed Central

Background and Aims We tested the effects of recombinant insulin-like growth factor-I (IGF-I) in an adipocyte model of HIV lipodystrophy and in an open label study on body composition and metabolism in patients with HIV lipodystrophy. Methods The effects of IGF-I on ritonavir-induced adipocyte cell death were studied in vitro. We assessed lipid accumulation, IGF signaling, apoptosis, and gene expression. We conducted a 24-week open label trial of recombinant IGF-I in ten adults with HIV associated lipoatrophy. Laboratory assessments included glucose, insulin, lipids, and IGF-I. At weeks 0 and 24, body composition studies were performed including skinfold measurement, dual-energy x-ray absorptiometry, and computed tomography of the abdomen and thigh. Results In vitro, ritonavir increased delipidation and apoptosis of adipocytes, whereas co-treatment with IGF-I attenuated the effect. In the clinical study, subcutaneous adipose tissue did not increase in patients after treatment with IGF-I; however, there was a decrease in the proportion of abdominal fat (39.8 ± 7% vs. 34.6 ± 7%, p = 0.007). IGF-I levels increased with treatment (143 ± 28 µg/L at week 0 vs. 453 ± 212 µg/L at week 24, p = 0.002), whereas IGFBP-3 levels declined (3.554 ± 1.146 mg/L vs. 3.235 ± 1.151 mg/L, p = 0.02). Insulin at week 12 week decreased significantly (90.1 ± 39.8 pmol/L vs. 33.2 ± 19.6 pmol/L, p = 0.002). There was a nonsignificant decrease in visceral adipose tissue (155.2 ± 68 cm2 at week 0 vs. 140.6 ± 70 cm2 at week 24, p = 0.08). Conclusions Use of recombinant IGF-I may lower fasting insulin and abdominal fat in patients with lipoatrophy associated with HIV infection. Further evaluation of this agent for treatment of HIV-associated lipodystrophy may be warranted. PMID:23867790

Kim, Roy J.; Vaghani, Sumit; Zifchak, Larisa M.; Quinn, Joseph H.; He, Weimian; Tebas, Pablo; Frank, Ian

2013-01-01

222

HIV Associated Neurocognitive Disorders (HAND) in Malawian Adults and Effect on Adherence to Combination Anti-Retroviral Therapy: A Cross Sectional Study  

PubMed Central

Background Little is known about the prevalence and burden of HIV associated neurocognitive disorder (HAND) among patients on combination antiretroviral therapy (cART) in sub-Saharan Africa. We estimated the prevalence of HAND in adult Malawians on cART and investigated the relationship between HAND and adherence to cART. Methods HIV positive adults in Blantyre, Malawi underwent a full medical history, neurocognitive test battery, depression score, Karnofsky Performance Score and adherence assessment. The Frascati criteria were used to diagnose HAND and the Global Deficit Score (GDS) was also assessed. Blood was drawn for CD4 count and plasma nevirapine and efavirenz concentrations. HIV negative adults were recruited from the HIV testing clinic to provide normative scores for the neurocognitive battery. Results One hundred and six HIV positive patients, with median (range) age 39 (18–71) years, 73% female and median (range) CD4 count 323.5 (68–1039) cells/µl were studied. Symptomatic neurocognitive impairment was present in 15% (12% mild neurocognitive disorder [MND], 3% HIV associated dementia [HAD]). A further 55% fulfilled Frascati criteria for asymptomatic neurocognitive impairment (ANI); however factors other than neurocognitive impairment could have confounded this estimate. Neither the symptomatic (MND and HAD) nor asymptomatic (ANI) forms of HAND were associated with subtherapeutic nevirapine/efavirenz concentrations, adjusted odds ratio 1.44 (CI. 0.234, 8.798; p?=?0.696) and aOR 0.577 (CI. 0.09, 3.605; p?=?0.556) respectively. All patients with subtherapeutic nevirapine/efavirenz levels had a GDS of less than 0.6, consistent with normal neurocognition. Discussion/Conclusion Fifteen percent of adult Malawians on cART had a diagnosis of MND or HAD. Subtherapeutic drug concentrations were found exclusively in patients with normal neurocognitive function suggesting HAND did not affect cART adherence. Further study of HAND requires more robust locally derived normative neurocognitive values and determination of the clinical relevance of ANI. PMID:24915530

Kelly, Christine M.; van Oosterhout, Joep J.; Ngwalo, Chisomo; Stewart, Robert C.; Benjamin, Laura; Robertson, Kevin R.; Khoo, Saye; Allain, Theresa J.; Solomon, Tom

2014-01-01

223

Opportunistic Adaptation in Start-Up Companies - Exploring the links between business model learning and the resource base  

Microsoft Academic Search

It has been proposed that a key success factor for entrepreneurial start-up companies in dynamic industries is their capacity to continuously adapt their business opportunistically. However, the concept of opportunistic adaptation is in need of further development and clarification in order to make it possible to empirically test its usefulness, something that this far has been done only to a

Linda Andrén; Mats Magnusson; Sören Sjölander

224

IEEE TRANSACTIONS ON SMART GRID, VOL. 5, NO. 1, JANUARY 2014 303 Opportunistic Routing for Smart Grid With Power  

E-print Network

IEEE TRANSACTIONS ON SMART GRID, VOL. 5, NO. 1, JANUARY 2014 303 Opportunistic Routing for Smart communications (PLCs) have recently absorbed interest in the smart grid since they offer communi- cation--Access network, narrowband PLC, opportunistic routing, power line communications, smart grid. I. INTRODUCTION

Bahk, Saewoong

225

Joint Network-wide Opportunistic Scheduling and Power Control in Multi-cell Networks  

Microsoft Academic Search

We present a unified analytical framework that maxi- mizes generalized utilities of a wireless network by networ k- wide opportunistic scheduling and power control. That is, base stations in the network jointly decide mobile stations to be served at the same time as the transmission powers of base stations are coordinated to mitigate the mutually inte r- fering effect. Although

Jeong-woo Cho; Jeonghoon Mo; Song Chong

2007-01-01

226

Joint network-wide opportunistic scheduling and power control in multi-cell networks  

Microsoft Academic Search

We present a unified analytical framework that maximizes generalized utilities of a wireless network by network-wide opportunistic scheduling and power control. That is, base stations in the network jointly decide mobile stations to be served at the same time as the transmission powers of base stations are coordinated to mitigate the mutually interfering effect. Although the maximization at the first

Jeong-woo Cho; Jeonghoon Mo; Song Chong

2009-01-01

227

PePiT: Opportunistic Dissemination of Large Contents on Android Mobile Devices  

E-print Network

PePiT: Opportunistic Dissemination of Large Contents on Android Mobile Devices Matteo Sammarco this in- formation to transfer less prevalent pieces first. In this paper, we present PePiT, an Android application based on PACS. PePiT enables the dissemination of pictures between collocated Android devices

Paris-Sud XI, Université de

228

Epithelial IL-22RA1-Mediated Fucosylation Promotes Intestinal Colonization Resistance to an Opportunistic Pathogen  

PubMed Central

Summary Our intestinal microbiota harbors a diverse microbial community, often containing opportunistic bacteria with virulence potential. However, mutualistic host-microbial interactions prevent disease by opportunistic pathogens through poorly understood mechanisms. We show that the epithelial interleukin-22 receptor IL-22RA1 protects against lethal Citrobacter rodentium infection and chemical-induced colitis by promoting colonization resistance against an intestinal opportunistic bacterium, Enterococcus faecalis. Susceptibility of Il22ra1?/? mice to C. rodentium was associated with preferential expansion and epithelial translocation of pathogenic E. faecalis during severe microbial dysbiosis and was ameloriated with antibiotics active against E. faecalis. RNA sequencing analyses of primary colonic organoids showed that IL-22RA1 signaling promotes intestinal fucosylation via induction of the fucosyltransferase Fut2. Additionally, administration of fucosylated oligosaccharides to C. rodentium-challenged Il22ra1?/? mice attenuated infection and promoted E. faecalis colonization resistance by restoring the diversity of anaerobic commensal symbionts. These results support a model whereby IL-22RA1 enhances host-microbiota mutualism to limit detrimental overcolonization by opportunistic pathogens. PMID:25263220

Pham, Tu Anh N.; Clare, Simon; Goulding, David; Arasteh, Julia M.; Stares, Mark D.; Browne, Hilary P.; Keane, Jacqueline A.; Page, Andrew J.; Kumasaka, Natsuhiko; Kane, Leanne; Mottram, Lynda; Harcourt, Katherine; Hale, Christine; Arends, Mark J.; Gaffney, Daniel J.; Dougan, Gordon; Lawley, Trevor D.

2014-01-01

229

Traitement d'Image Embarqu et Communication Opportuniste sur Drones Lgers pour Systmes de  

E-print Network

Traitement d'Image Embarqué et Communication Opportuniste sur Drones Légers pour Systèmes de Surveillance Contexte : Les drones sont en passe de devenir des systèmes de surveillance performants et niveau de qualité et de versatilité, les drones se doivent de fournir un certain nombre de services

Jeanjean, Louis

230

Cell-Share: Opportunistic Use of Cellular Uplink to Augment Rural WiFi Mesh Networks  

E-print Network

-channel using a collaborative mobile phone framework. We implement Cell-Share on Windows Mobile and AndroidCell-Share: Opportunistic Use of Cellular Uplink to Augment Rural WiFi Mesh Networks Ashish Sharma@computer.org Department of Computer Science, University of California, Santa Barbara, CA, USA WiChorus Inc., San Jose, CA

Belding-Royer, Elizabeth M.

231

Space Division Multiplexing Aided Opportunistic Spectrum Access for Cognitive Radio Networks  

Microsoft Academic Search

This paper proposes a space division multiplexing aided opportunistic spectrum access (SDM-OSA) scheme for cognitive radio networks by exploiting the spatial signal pro- cessing ability provided by multiple antennas. With the scheme, cognitive transmission could be carried out using SDM even though there is no idle spectrum resource available. We make further discussion about antenna requirements for cognitive system. When

Zhao Li; Qin Liu; Linjing Zhao

2011-01-01

232

Emerging and opportunistic diseases are caused by a microorganism invading a new  

E-print Network

Emerging and opportunistic diseases are caused by a microorganism invading a new habitat, either is derived from population ecology, where the `sink' population is only maintained by immigration from­sink model Source­sink ecological models6 were developed, and are currently applied, in the population

Gomulkiewicz, Richard

233

Opportunistic screening for Chlamydia trachomatis in men attending three different secondary healthcare settings  

Microsoft Academic Search

Objectives: To assess the feasibility and acceptability of opportunistic Chlamydia trachomatis (CT) screening of asymptomatic men attending three different secondary healthcare settings and to investigate CT positivity in these settings.Methods: Men attending fracture, fertility and family planning (FP) clinics were invited to be screened by first-void urine and complete a questionnaire which collected demographic, sexual and behavioural characteristics, and their

S Sripada; S Logan; S McGillivray; H Mckenzie; A Templeton; A Sutherland; S Bhattacharya

2007-01-01

234

Cluster-Based Spectrum Sensing Architecture for Opportunistic Spectrum Access Networks  

Microsoft Academic Search

In opportunistic spectrum access networks (OSAN) procedures for spectrum sensing have to be designed in such a way that the probability of miss-detection and false alarm, should not exceed a certain level, while detecting the presence of the licensed user (LU) of a radio channel. One of the approaches - that minimizes the error in detection - is to combine

Przemysaw Paweczak; Cheng Guo; R. Venkatesha; Ramin Hekmat

235

Opportunistic spectrum use for sensor networks: the need for local cooperation  

E-print Network

Opportunistic spectrum use for sensor networks: the need for local cooperation Anant Sahai Rahul to popular belief, actual measurements show that most of the allocated spectrum is vastly underutilized system of spectrum allocation, rigid partitioning has resulted in vastly underutilized spectrum bands

Sahai, Anant

236

Device discovery and connection establishment approach using Ad-Hoc Wi-Fi for opportunistic networks  

Microsoft Academic Search

We propose a device discovery approach and connection establishment scheme for opportunistic networks using Ad-Hoc Wi-Fi as the underlying communication technology. We employ beacon stuffing method for a device to announce its existence in its neighborhood by broadcasting beacons stuffed with useful information in the field of SSID to remote devices. This method can allow a device to discover multiple

Shanshan Lu; Sankalp Shere; Yanliang Liu; Yonghe Liu

2011-01-01

237

Poster Abstract: User-Centric Radio Power Control for Opportunistic Mountain Hiking Networks  

E-print Network

Multiple Access based ones, and Low Power Listening ones by turning the listener's radio onPoster Abstract: User-Centric Radio Power Control for Opportunistic Mountain Hiking Networks Jyh for DTNs' radio power duty cycling which is suitable for User Centric Sensor Networks. We extended the work

Ouhyoung, Ming

238

Cell Wall Chitosan Is Necessary for Virulence in the Opportunistic Pathogen Cryptococcus neoformans ?  

PubMed Central

Cryptococcus neoformans is an opportunistic fungal pathogen that causes meningoencephalitis. Its cell wall is composed of glucans, proteins, chitin, and chitosan. Multiple genetic approaches have defined a chitosan-deficient syndrome that includes slow growth and decreased cell integrity. Here we demonstrate chitosan is necessary for virulence and persistence in the mammalian host. PMID:21784998

Baker, Lorina G.; Specht, Charles A.; Lodge, Jennifer K.

2011-01-01

239

Epithelial IL-22RA1-Mediated Fucosylation Promotes Intestinal Colonization Resistance to an Opportunistic Pathogen.  

PubMed

Our intestinal microbiota harbors a diverse microbial community, often containing opportunistic bacteria with virulence potential. However, mutualistic host-microbial interactions prevent disease by opportunistic pathogens through poorly understood mechanisms. We show that the epithelial interleukin-22 receptor IL-22RA1 protects against lethal Citrobacter rodentium infection and chemical-induced colitis by promoting colonization resistance against an intestinal opportunistic bacterium, Enterococcus faecalis. Susceptibility of Il22ra1(-/-) mice to C. rodentium was associated with preferential expansion and epithelial translocation of pathogenic E. faecalis during severe microbial dysbiosis and was ameloriated with antibiotics active against E. faecalis. RNA sequencing analyses of primary colonic organoids showed that IL-22RA1 signaling promotes intestinal fucosylation via induction of the fucosyltransferase Fut2. Additionally, administration of fucosylated oligosaccharides to C. rodentium-challenged Il22ra1(-/-) mice attenuated infection and promoted E. faecalis colonization resistance by restoring the diversity of anaerobic commensal symbionts. These results support a model whereby IL-22RA1 enhances host-microbiota mutualism to limit detrimental overcolonization by opportunistic pathogens. PMID:25263220

Pham, Tu Anh N; Clare, Simon; Goulding, David; Arasteh, Julia M; Stares, Mark D; Browne, Hilary P; Keane, Jacqueline A; Page, Andrew J; Kumasaka, Natsuhiko; Kane, Leanne; Mottram, Lynda; Harcourt, Katherine; Hale, Christine; Arends, Mark J; Gaffney, Daniel J; Dougan, Gordon; Lawley, Trevor D

2014-10-01

240

Self-Interference Aware Opportunistic Routing Metric in Wireless Mesh Networks Nikolay KuznetsovO  

E-print Network

Self-Interference Aware Opportunistic Routing Metric in Wireless Mesh Networks Nikolay Kuznetsov and self-interference as synonyms. In this paper, we introduce a new routing metric called Self define a participation probability for each node. It stands for a probability of a node being an actual

Bahk, Saewoong

241

Opportunistic pathogens in roof-captured rainwater samples, determined using quantitative PCR.  

PubMed

In this study, quantitative PCR (qPCR) was used for the detection of four opportunistic bacterial pathogens in water samples collected from 72 rainwater tanks in Southeast Queensland, Australia. Tank water samples were also tested for fecal indicator bacteria (Escherichia coli and Enterococcus spp.) using culture-based methods. Among the 72 tank water samples tested, 74% and 94% samples contained E. coli and Enterococcus spp., respectively, and the numbers of E. coli and Enterococcus spp. in tank water samples ranged from 0.3 to 3.7 log?? colony forming units (CFU) per 100 mL of water. In all, 29%, 15%, 13%, and 6% of tank water samples contained Aeromonas hydrophila, Staphylococcus aureus, Pseudomonas aeruginosa and Legionella pneumophila, respectively. The genomic units (GU) of opportunistic pathogens in tank water samples ranged from 1.5 to 4.6 log?? GU per 100 mL of water. A significant correlation was found between E. coli and Enterococcus spp. numbers in pooled tank water samples data (Spearman's rs = 0.50; P < 0.001). In contrast, fecal indicator bacteria numbers did not correlate with the presence/absence of opportunistic pathogens tested in this study. Based on the results of this study, it would be prudent, to undertake a Quantitative Microbial Risk Assessment (QMRA) analysis of opportunistic pathogens to determine associated health risks for potable and nonpotable uses of tank water. PMID:24531256

Ahmed, W; Brandes, H; Gyawali, P; Sidhu, J P S; Toze, S

2014-04-15

242

Complete Genome Sequence of Staphylococcus xylosus HKUOPL8, a Potential Opportunistic Pathogen of Mammals  

PubMed Central

We report here the first complete genome sequence of Staphylococcus xylosus strain HKUOPL8, isolated from giant panda feces. The whole genome sequence of this strain will provide an important framework for investigating the genes responsible for potential opportunistic infections with this species, as well as its survival in various environments. PMID:25059860

Ma, Angel Po Yee; Jiang, Jingwei; Tun, Hein Min; Mauroo, Nathalie France; Yuen, Chan San

2014-01-01

243

Loss of Competition in the Outside Host Environment Generates Outbreaks of Environmental Opportunist Pathogens  

PubMed Central

Environmentally transmitted pathogens face ecological interactions (e.g., competition, predation, parasitism) in the outside-host environment and host immune system during infection. Despite the ubiquitousness of environmental opportunist pathogens, traditional epidemiology focuses on obligatory pathogens incapable of environmental growth. Here we ask how competitive interactions in the outside-host environment affect the dynamics of an opportunist pathogen. We present a model coupling the classical SI and Lotka–Volterra competition models. In this model we compare a linear infectivity response and a sigmoidal infectivity response. An important assumption is that pathogen virulence is traded off with competitive ability in the environment. Removing this trade-off easily results in host extinction. The sigmoidal response is associated with catastrophic appearances of disease outbreaks when outside-host species richness, or overall competition pressure, decreases. This indicates that alleviating outside-host competition with antibacterial substances that also target the competitors can have unexpected outcomes by providing benefits for opportunist pathogens. These findings may help in developing alternative ways of controlling environmental opportunist pathogens. PMID:24244752

Anttila, Jani; Ruokolainen, Lasse; Kaitala, Veijo; Laakso, Jouni

2013-01-01

244

Residual White Space Distribution-Based Opportunistic Channel Access for Cognitive Radio Enabled Devices  

E-print Network

(usually referred as white spaces or holes) in various spectrum bands by allow- ing secondary devicesResidual White Space Distribution-Based Opportunistic Channel Access for Cognitive Radio Enabled to use these white spaces for their communication. The OSA scheme strives to maximize the secondary node

Sahoo, Anirudha

245

Optimization of opportunistic replacement activities: A case study in the aircraft industry  

E-print Network

. When an aircraft engine is removed for overhaul, it needs to be replaced by a spare engine aircrafts during the maintenance period. This is normally achieved by the use of spare enginesOptimization of opportunistic replacement activities: A case study in the aircraft industry Torgny

Patriksson, Michael

246

Exploiting Multi-Antennas for Opportunistic Spectrum Sharing in Cognitive Radio Networks  

Microsoft Academic Search

In cognitive radio (CR) networks, there are scenarios where the secondary (lower priority) users intend to communicate with each other by opportunistically utilizing the transmit spectrum originally allocated to the existing primary (higher priority) users. For such a scenario, a secondary user usually has to tradeoff between two conflicting goals at the same time: one is to maximize its own

Rui Zhang; Ying-Chang Liang

2008-01-01

247

Optimization of Spectrum Sensing for Opportunistic Spectrum Access in Cognitive Radio Networks  

Microsoft Academic Search

Motivated by the low utilization of the licensed spectrum across many frequency bands, sensing-based oppor- tunistic spectrum access has recently emerged as an alternative to the outdated exclusive spectrum access policy. Under this new paradigm, a secondary (unlicensed) user monitors a primary (licensed) frequency band for a given time and opportunistically transmits if it does not detect any ongoing licensed

Amir Ghasemi; Elvino S. Sousa

2007-01-01

248

Appears in Proceedings of PACT-18, Sep. 2009. CPROB: Checkpoint Processing with Opportunistic Minimal Recovery  

E-print Network

. Checkpoints exist before instructions B (Checkpoint 1) and G (Checkpoint 2). All instructions exceptAppears in Proceedings of PACT-18, Sep. 2009. CPROB: Checkpoint Processing with Opportunistic, University of Pennsylvania {adhilton, neeraj, amir}@cis.upenn.edu Abstract--CPR (Checkpoint Processing

Roth, Amir

249

Opportunistic Collaboration: Unlocking the Archives of the Birmingham Institute of Art and Design  

ERIC Educational Resources Information Center

Purpose: To review a small specialist repository's strategic and opportunistic approach to utilising collaborative regional and national digital initiatives to increase access. The Birmingham Institute of Art and Design (BIAD) Archives activity is evaluated to determine whether a project-based approach recognises and meets the needs of historians,…

Everitt, Sian

2005-01-01

250

JOINT PHY-MAC DESIGN FOR OPPORTUNISTIC SPECTRUM ACCESS WITH MULTI-CHANNEL SENSING  

E-print Network

JOINT PHY-MAC DESIGN FOR OPPORTUNISTIC SPECTRUM ACCESS WITH MULTI-CHANNEL SENSING Yunxia Chen, Qing are a spectrum sensor at the physical (PHY) layer and a sensing and an access strategy at the MAC layer. Within at the PHY layer and the other at the MAC layer. Simulation re- sults indicate that the exploitation

Islam, M. Saif

251

Genome Sequence of Aureobasidium pullulans AY4, an Emerging Opportunistic Fungal Pathogen with Diverse Biotechnological Potential  

PubMed Central

Aureobasidium pullulans AY4 is an opportunistic pathogen that was isolated from the skin of an immunocompromised patient. We present here the draft genome of strain AY4, which reveals an abundance of genes relevant to bioindustrial applications, including biocontrol and biodegradation. Putative genes responsible for the pathogenicity of strain AY4 were also identified. PMID:23104371

Bamadhaj, Hasima Mustafa; Gan, Han Ming; Rashid, Noor Aini Abdul

2012-01-01

252

A channel-aided cross-layer opportunistic forwarding scheme for multihop wireless networks  

Microsoft Academic Search

In this paper, we firstly develop link state change of wireless error link to improve packet successful delivery percentage and reduce collision probability of wireless Mesh networks. Based on statistics of link layer quality and the adaptive retransmission strategy, a channel-aided cross-layer opportunistic routing scheme CCOR for wireless Mesh networks is proposed to cope with the unreliable transmissions by exploiting

Zhao Haitao; Dong Yuning; Zhang Hui; Zhao Xinxing

2010-01-01

253

Aquatic Mammals 2003, 29.1, 104107 Opportunistic carnivory by Florida manatees (Trichechus manatus  

E-print Network

Aquatic Mammals 2003, 29.1, 104­107 Opportunistic carnivory by Florida manatees (Trichechus manatus, Orlando, FL 32816, USA Abstract The Florida manatee (Trichechus manatus lati- rostris) is one of the most ecology to de ne critical habitats. Manatees generally are con- sidered to be strictly herbivious mammals

254

Common Cold  

NSDL National Science Digital Library

This Web site provides comprehensive information, selected by medical doctors, about the common cold. "The goal is to provide a framework for critical thinking which will allow informed decisions about medical care for the common cold." The section entitled Understanding Colds gives a detailed overview of how the cold virus invades the human body and how cold symptoms are caused. Information about preventing colds, and some of the complications that can occur are also included. The Special Features section includes one of the most interesting parts of the site -- Myths of the Common Cold. This site should be interesting to almost anyone, but perhaps more so for those of us who have recently had a cold.

1999-01-01

255

HIV-1 Tat upregulates expression of histone deacetylase-2 (HDAC2) in human neurons: implication for HIV-associated neurocognitive disorder (HAND).  

PubMed

Histone deacetylases (HDACs) play a pivotal role in epigenetic regulation of transcription and homeostasis of protein acetylation in histones and other proteins involved in chromatin remodeling. Histone hypoacetylation and transcriptional dysfunction have been shown to be associated with a variety of neurodegenerative diseases. More recently, neuron specific overexpression of HDAC2 has been shown to modulate synaptic plasticity and learning behavior in mice. However, the role of HDAC2 in development of HIV-associated neurocognitive disorders (HAND) is not reported. Herein we report that HIV-1 Tat protein upregulate HDAC2 expression in neuronal cells leading to transcriptional repression of genes involved in synaptic plasticity and neuronal function thereby contributing to the progression of HAND. Our results indicate upregulation of HDAC2 by Tat treatment in dose and time dependant manner by human neuroblastoma SK-N-MC cells and primary human neurons. Further, HDAC2 overexpression was associated with concomitant downregulation in CREB and CaMKIIa genes that are known to regulate neuronal activity. These observed effects were completely blocked by HDAC2 inhibition. These results for the first time suggest the possible role of HDAC2 in development of HAND. Therefore, use of HDAC2 specific inhibitor in combination with HAART may be of therapeutic value in treatment of neurocognitive disorders observed in HIV-1 infected individuals. PMID:21315782

Saiyed, Zainulabedin M; Gandhi, Nimisha; Agudelo, Marisela; Napuri, Jessica; Samikkannu, Thangavel; Reddy, Pichili V B; Khatavkar, Pradnya; Yndart, Adriana; Saxena, Shailendra K; Nair, Madhavan P N

2011-05-01

256

Intra-individual Neurocognitive Variability Confers Risk of Dependence in Activities of Daily Living among HIV-Seropositive Individuals without HIV-Associated Neurocognitive Disorders  

PubMed Central

Although HIV-associated neurocognitive disorders (HAND) are the strong predictors of everyday functioning difficulties, approximately half of all functionally impaired individuals are labeled “neurocognitively normal” according to the standard neuropsychological measures, suggesting that novel predictors of functional problems in this prevalent subgroup are needed. The present study hypothesized that increased neurocognitive intra-individual variability as indexed by dispersion would be associated with poor daily functioning among 82 persons with HIV infection who did not meet research criteria for HAND. An intra-individual standard deviation was calculated across the demographically adjusted T-scores of 13 standard neuropsychological tests to represent dispersion, and functional outcomes included self-reported declines in basic and instrumental activities of daily functioning (basic activity of daily living [BADL] and instrumental activity of daily living [IADL], respectively) and medication management. Dispersion was a significant predictor of medication adherence and dependence in both BADL and IADL, even when other known predictors of functional status (i.e., age, affective distress, and indices of disease severity) were included in the models. As a significant and unique predictor of a performance on the range of daily functioning activities, neurocognitive dispersion may be indicative of deficient cognitive control expressed as inefficient regulation of neurocognitive resources in the context of competing functional demands. As such, dispersion may have clinical utility in detecting risk for functional problems among HIV-infected individuals without HAND. PMID:22337933

Morgan, Erin E.; Woods, Steven Paul; Grant, Igor

2012-01-01

257

Short-term efficacy of the IL6 receptor antibody tocilizumab in patients with HIV-associated multicentric Castleman disease: report of two cases  

PubMed Central

Multicentric Castleman disease (MCD) is a lymphoproliferative disorder caused by human herpesvirus 8 (HHV8) infection HIV associated MCD (HIV-MCD) presents with various clinical symptoms. Many HIV-negative MCD patients are often treated with anti-human interleukin-6 (IL6) receptor monoclonal antibodies (tocilizumab), and successful results have been reported. IL-6 plays an important role in the development of both HIV-positive and HIV-negative MCD; however, the efficacy of tocilizumab in HIV-MCD patients is unknown. We herein report the clinical and biologic courses of two HIV-MCD patients treated with tocilizumab. In both cases, a significant and rapid clinical improvement was observed after the first infusion. However, the treatment efficacy was not maintained for a long period, and relapse occurred at 15 and 22 weeks, respectively. Both patients received rituximab and subsequently achieved complete clinical remission. Our report, in addition to data presented in the literature, suggests that tocilizumab could be an initial treatment option in patients with HIV-MCD. PMID:24438824

2014-01-01

258

[Acute psychosis as a side effect of efavirenz therapy with metabolic anomalies : An important differential diagnosis of HIV-associated psychoses].  

PubMed

Among patients with human immunodeficiency virus (HIV) infections psychiatric disease poses a particular challenge for caregivers. Neuropsychiatric side effects of efavirenz have been described in up to 40?% of patients showing dizziness, insomnia, unusual dreams, mood instability, personality alterations and thought disorders. In immigrants from Africa and South America these side effects may be related to elevated plasma concentrations of efavirenz due to polymorphisms of cytochrome P450 isozymes (especially G516T). Alleles for these polymorphisms are more frequent in African and South American patients. We report a case of a 52-year-old patient from Guinea who was referred to the department of neurology under the diagnosis of HIV-associated neurocognitive disorder (HAND). Since the start of combined antiretroviral therapy (cART) including efavirenz the patient had suffered severe personality alterations, acoustic and visual hallucinations and delusions which led to discrimination and reduced quality of life. Diagnostic procedures including magnetic resonance imaging (MRT) and spinal fluid analysis resulted in normal values and did not explain the disease. After switching to nevirapin instead of efavirenz the psychotic symptoms disappeared within 5 days. PMID:25200885

Hinsch, M C; Reichelt, D; Husstedt, I W

2014-10-01

259

Objective evidence for the use of polylactic acid implants in HIV-associated facial lipoatrophy using three-dimensional surface laser scanning and psychological assessment.  

PubMed

The advent of highly active antiretroviral therapy (HAART) has dramatically improved the life expectancy of people infected with human immunodeficiency virus (HIV). Although patients often have excellent disease control with these combinations of antiretrovirals, they are at risk for the multiple toxicities associated with these drugs. Facial lipoatrophy is a particularly distressing complication of some HAART regimes. This disfigurement can lead to significant psychosocial stress, resulting in decreased treatment compliance. Polylactic acid (PLA) facial implants provide a potential method of restoring a normal appearance. One hundred consecutive patients had a course of PLA facial implants. All patients were assessed clinically and had photographs, facial surface laser scans and completed psychological questionnaires throughout the course of treatment. After a mean of 4.85 treatments per patient, there were improvements in all measures. The mean clinical scores improved from a moderate-severe grade to none-mild grade after treatment. Three-dimensional (3D) laser surface scans showed a volume increase of 2.81 cc over the treated area of the cheek. There were significant improvements in all of the psychological measures. This study shows clear objective evidence of the psychological and physical benefit of PLA implants in HIV-associated facial lipodystrophy. PMID:19036657

Ong, J; Clarke, A; White, P; Johnson, M A; Withey, S; Butler, P E M

2009-12-01

260

Microbial Monitoring of Common Opportunistic Pathogens by Comparing Multiple Real-Time PCR Platforms for Potential Space Applications  

NASA Technical Reports Server (NTRS)

Because the International Space Station is a closed environment with rotations of astronauts and equipment that each introduce their own microbial flora, it is necessary to monitor the air, surfaces, and water for microbial contamination. Current microbial monitoring includes labor- and time-intensive methods to enumerate total bacterial and fungal cells, with limited characterization, during in-flight testing. Although this culture-based method is sufficient for monitoring the International Space Station, on future long-duration missions more detailed characterization will need to be performed during flight, as sample return and ground characterization may not be available. At a workshop held in 2011 at NASA's Johnson Space Center to discuss alternative methodologies and technologies suitable for microbial monitoring for these long-term exploration missions, molecular-based methodologies such as polymerase chain reaction (PCR) were recommended. In response, a multi-center (Marshall Space Flight Center, Johnson Space Center, Jet Propulsion Laboratory, and Kennedy Space Center) collaborative research effort was initiated to explore novel commercial-off-the-shelf hardware options for space flight environmental monitoring. The goal was to evaluate quantitative or semi-quantitative PCR approaches for low-cost in-flight rapid identification of microorganisms that could affect crew safety. The initial phase of this project identified commercially available platforms that could be minimally modified to perform nominally in microgravity. This phase was followed by proof-of-concept testing of the highest qualifying candidates with a universally available challenge organism, Salmonella enterica. The analysis identified two technologies that were able to perform sample-to-answer testing with initial cell sample concentrations between 50 and 400 cells. In addition, the commercial systems were evaluated for initial flight safety and readiness.

Oubre, Cherie M.; Birmele, Michele N.; Castro, Victoria A.; Venkateswaran, Kasthuri J.; Vaishampayan, Parag A.; Jones, Kathy U.; Singhal, Adesh; Johnston, Angela S.; Roman, Monserrate C.; Ozbolt, Tamra A.; Jett, Daniel X.; Roberts, Michael S.; Ott, C. Mark

2013-01-01

261

Stress responses in the opportunistic pathogen Acinetobacter baumannii  

PubMed Central

Acinetobacter baumannii causes a wide range of severe infections among compromised and injured patients worldwide. The relevance of these infections are, in part, due to the ability of this pathogen to sense and react to environmental and host stress signals, allowing it to persist and disseminate in medical settings and the human host. This review summarizes current knowledge on the roles that environmental and cellular stressors play in the ability of A. baumannii to resist nutrient deprivation, oxidative and nitrosative injury, and even the presence of the commonly used antiseptic ethanol, which could serve as a nutrient- and virulence-enhancing signal rather than just being a convenient disinfectant. Emerging experimental evidence supports the role of some of these responses in the pathogenesis of the infections A. baumannii causes in humans and its capacity to resist antibiotics and host response effectors. PMID:23464372

Fiester, Steven E; Actis, Luis A

2013-01-01

262

Making the Common Good Common  

ERIC Educational Resources Information Center

How are independent schools to be useful to the wider world? Beyond their common commitment to educate their students for meaningful lives in service of the greater good, can they educate a broader constituency and, thus, share their resources and skills more broadly? Their answers to this question will be shaped by their independence. Any…

Chase, Barbara

2011-01-01

263

Opportunistic diseases in HIV-infected patients in Gabon following the administration of highly active antiretroviral therapy: a retrospective study.  

PubMed

Opportunistic diseases cause substantial morbidity and mortality to human immunodeficiency virus (HIV)-infected patients. Highly active antiretroviral therapy (HAART) leading to immune reconstitution is the most effective treatment of preventing opportunistic diseases. This retrospective study established an epidemiologic profile of opportunistic diseases 10 years after the introduction of HAART. The HIV antiretroviral therapy-naive patients matching inclusion criteria were included. The primary outcome was the prevalence of opportunistic diseases. From January 1, 2002 to September 30, 2010, 654 opportunistic diseases were identified in 458 patients. Pulmonary tuberculosis, herpes zoster, cerebral toxoplasmosis, oral candidiasis, and severe pneumonia accounted for 22.05%, 15.94%, 14.19%, 14.19%, and 9.39%, respectively. Cryptococcal meningitis and pneumocystosis accounted for 0.44% and 0.21%, respectively. The prevalence of opportunistic diseases in Gabon remains high. New guidelines emphasize the importance of initiating antiretroviral therapy early to reconstitute the immune system, and reduce disease risk, and treat the primary opportunistic infection of pulmonary tuberculosis. PMID:24323514

Okome-Nkoumou, Madeleine; Guiyedi, Vincent; Ondounda, Magloire; Efire, Nora; Clevenbergh, Philippe; Dibo, Mireille; Dzeing-Ella, Arnaud

2014-02-01

264

Diet composition of common ravens across the urban-wildland interface of the West Mojave Desert  

Microsoft Academic Search

Common ravens (Corvus corax) are human-subsidized scavengers and predators in the Mojave Desert. They have increased dramatically in number and have been implicated as contributors to the decline in desert tortoise (Gopherus agassizii) populations. Known patterns of increased fledging success near human developments suggested that food was the most likely resource subsidy received by ravens. Because ravens are opportunistic foragers

William B. Kristan; William I. Boarman; John J. Crayon

2004-01-01

265

Diagnostic accuracy of a low-cost, urine antigen, point-of-care screening assay for HIV-associated pulmonary tuberculosis before antiretroviral therapy: a descriptive study  

PubMed Central

Summary Background The diagnostic accuracy of sputum smear microscopy and routine chest radiology for HIV-associated tuberculosis is poor, and culture-based diagnosis is slow, expensive, and is unavailable in most resource-limited settings. We assessed the diagnostic accuracy of a urine antigen test Determine TB-LAM Ag (Determine TB-LAM; Alere, Waltham, MA, USA) for screening for HIV-associated pulmonary tuberculosis before antiretroviral therapy (ART). Methods In this descriptive study, consecutive adults referred to a community-based ART clinic in Gugulethu township, South Africa, were all screened for tuberculosis by obtaining sputum samples for fluorescence microscopy, automated liquid culture (gold-standard test), and Xpert MTB/RIF assays (Cepheid, Sunnyvale, CA, USA) and urine samples for the Clearview TB-ELISA (TB-ELISA; Alere, Waltham, MA, USA) and Determine TB-LAM test. Patients with Mycobacterium tuberculosis cultured from one or more sputum samples were defined as cases of tuberculosis. The diagnostic accuracy of Determine TB-LAM used alone or combined with sputum smear microscopy was compared with that of sputum culture and the Xpert MTB/RIF assay for all patients and subgroups of patients stratified by CD4 cell count. Findings Patients were recruited between March 12, 2010, and April 20, 2011. Of 602 patients enrolled, 542 were able to provide one or more sputum samples, and 94 had culture-positive tuberculosis (prevalence 17·4%, 95% CI 14·2–20·8). Complete results from all tests were available for 516 patients (median CD4 count, 169·5 cells per ?L; IQR 100–233), including 85 culture-positive tuberculosis, 24 of whom (28·2%, 95% CI 19·0–39·0) had sputum smear-positive disease. Determine TB-LAM test strips provided results within 30 min. Agreement was very high between two independent readers of the test strips (?=0·97) and between the test strips and TB-ELISA (?=0·84). Determine TB-LAM had highest sensitivity at low CD4 cell counts: 66·7% (95% CI 41·0–86·7) at <50 cells per ?L, 51·7% (32·5–70·6) at <100 cells per ?L, and 39·0% (26·5–52·6) at <200 cells per ?L; specificity was greater than 98% for all strata. When combined with smear microscopy (either test positive), sensitivity was 72·2% (95% CI 46·5–90·3) at CD4 counts less than 50 cells per ?L, 65·5% (45·7–82·1) at less than 100 cells per ?L, and 52·5% (39·1–65·7) at less than 200 cells per ?L, which did not differ statistically from the sensitivities obtained by testing a single sputum sample with the Xpert MTB/RIF assay. Interpretation Determine TB-LAM is a simple, low-cost, alternative to existing diagnostic assays for tuberculosis screening in HIV-infected patients with very low CD4 cell counts and provides important incremental yield when combined with sputum smear microscopy. Funding Wellcome Trust. PMID:22015305

Lawn, Stephen D; Kerkhoff, Andrew D; Vogt, Monica; Wood, Robin

2012-01-01

266

Identification of an Abbreviated Test Battery for Detection of HIV-Associated Neurocognitive Impairment in an Early-Managed HIV-Infected Cohort  

PubMed Central

Background HIV-associated neurocognitive disorders (HAND) remain prevalent despite improved antiretroviral treatment (ART), and it is essential to have a sensitive and specific HAND screening tool. Methods Participants were 200 HIV-infected US military beneficiaries, managed early in the course of HIV infection, had few comorbidities, and had open access to ART. Participants completed a comprehensive, seven-domain (16-test), neuropsychological battery (?120 min); neurocognitive impairment (NCI) was determined using a standardized score derived from demographically adjusted T-scores (global deficit score ?0.5). Restricting the estimated administration time of the screening battery to

Moore, David J.; Roediger, Mollie J. P.; Eberly, Lynn E.; Blackstone, Kaitlin; Hale, Braden; Weintrob, Amy; Ganesan, Anuradha; Agan, Brian K.; Letendre, Scott L.; Crum-Cianflone, Nancy F.

2012-01-01

267

Clinical Presentation, Treatment, and Outcomes Among 65 Patients with HIV-Associated Lymphoma Treated at the University of North Carolina, 2000-2010  

PubMed Central

Abstract HIV increases risk of non-Hodgkin lymphoma (NHL) and Hodgkin lymphoma (HL). The effect of HIV on presentation, treatment, and outcomes of NHL and HL in routine care in the combination antiretroviral therapy (cART) merits further characterization. We performed a retrospective analysis of HIV-infected patients with NHL and HL receiving care at the University of North Carolina at Chapel Hill from January 1, 2000 until December 31, 2010. Statistical analyses were conducted using SAS, version 9.2 (SAS Institute Inc). Sixty-five HIV-infected patients with NHL and HL were identified. Patients with non-CNS NHL and HL presented with advanced disease (85% stage III or IV) and adverse prognostic features. Patients completed 87% of planned chemotherapy cycles, and 68% of patients completed stage-appropriate therapy. Dose reduction, interruption, and/or delay occurred during more than 25% of administered cycles in 64% of patients. Infectious complications, febrile neutropenia, and myelosuppression accounted for 78% of deviations from planned cumulative dose and dose intensity. Primary CNS lymphoma (PCNSL) was associated with poor prognosis, but 2-year overall survival was 66% for all non-CNS lymphoma. Among patients surviving at least 2 years, 75% had CD4 count >200 cells/?l and 79% had HIV viral load <400 copies/ml at last follow-up. Despite advanced disease and difficulty tolerating chemotherapy with optimal cumulative dose and dose intensity, most patients with non-CNS HIV-associated lymphoma survived more than 2 years after diagnosis, the majority with suppressed HIV RNA. PMID:22011066

Martin, Kelly E.; Richards, Kristy L.; Eron, Joseph J.

2012-01-01

268

Human synaptic plasticity gene expression profile and dendritic spine density changes in HIV-infected human CNS cells: role in HIV-associated neurocognitive disorders (HAND).  

PubMed

HIV-associated neurocognitive disorders (HAND) is characterized by development of cognitive, behavioral and motor abnormalities, and occur in approximately 50% of HIV infected individuals. Our current understanding of HAND emanates mainly from HIV-1 subtype B (clade B), which is prevalent in USA and Western countries. However very little information is available on neuropathogenesis of HIV-1 subtype C (clade C) that exists in Sub-Saharan Africa and Asia. Therefore, studies to identify specific neuropathogenic mechanisms associated with HAND are worth pursuing to dissect the mechanisms underlying this modulation and to prevent HAND particularly in clade B infection. In this study, we have investigated 84 key human synaptic plasticity genes differential expression profile in clade B and clade C infected primary human astrocytes by using RT(2) Profile PCR Array human Synaptic Plasticity kit. Among these, 31 and 21 synaptic genes were significantly (?3 fold) down-regulated and 5 genes were significantly (?3 fold) up-regulated in clade B and clade C infected cells, respectively compared to the uninfected control astrocytes. In flow-cytometry analysis, down-regulation of postsynaptic density and dendrite spine morphology regulatory proteins (ARC, NMDAR1 and GRM1) was confirmed in both clade B and C infected primary human astrocytes and SK-N-MC neuroblastoma cells. Further, spine density and dendrite morphology changes by confocal microscopic analysis indicates significantly decreased spine density, loss of spines and decreased dendrite diameter, total dendrite and spine area in clade B infected SK-N-MC neuroblastoma cells compared to uninfected and clade C infected cells. We have also observed that, in clade B infected astrocytes, induction of apoptosis was significantly higher than in the clade C infected astrocytes. In conclusion, this study suggests that down-regulation of synaptic plasticity genes, decreased dendritic spine density and induction of apoptosis in astrocytes may contribute to the severe neuropathogenesis in clade B infection. PMID:23620748

Atluri, Venkata Subba Rao; Kanthikeel, Sudheesh P; Reddy, Pichili V B; Yndart, Adriana; Nair, Madhavan P N

2013-01-01

269

Human Synaptic Plasticity Gene Expression Profile and Dendritic Spine Density Changes in HIV-Infected Human CNS Cells: Role in HIV-Associated Neurocognitive Disorders (HAND)  

PubMed Central

HIV-associated neurocognitive disorders (HAND) is characterized by development of cognitive, behavioral and motor abnormalities, and occur in approximately 50% of HIV infected individuals. Our current understanding of HAND emanates mainly from HIV-1 subtype B (clade B), which is prevalent in USA and Western countries. However very little information is available on neuropathogenesis of HIV-1 subtype C (clade C) that exists in Sub-Saharan Africa and Asia. Therefore, studies to identify specific neuropathogenic mechanisms associated with HAND are worth pursuing to dissect the mechanisms underlying this modulation and to prevent HAND particularly in clade B infection. In this study, we have investigated 84 key human synaptic plasticity genes differential expression profile in clade B and clade C infected primary human astrocytes by using RT2 Profile PCR Array human Synaptic Plasticity kit. Among these, 31 and 21 synaptic genes were significantly (?3 fold) down-regulated and 5 genes were significantly (?3 fold) up-regulated in clade B and clade C infected cells, respectively compared to the uninfected control astrocytes. In flow-cytometry analysis, down-regulation of postsynaptic density and dendrite spine morphology regulatory proteins (ARC, NMDAR1 and GRM1) was confirmed in both clade B and C infected primary human astrocytes and SK-N-MC neuroblastoma cells. Further, spine density and dendrite morphology changes by confocal microscopic analysis indicates significantly decreased spine density, loss of spines and decreased dendrite diameter, total dendrite and spine area in clade B infected SK-N-MC neuroblastoma cells compared to uninfected and clade C infected cells. We have also observed that, in clade B infected astrocytes, induction of apoptosis was significantly higher than in the clade C infected astrocytes. In conclusion, this study suggests that down-regulation of synaptic plasticity genes, decreased dendritic spine density and induction of apoptosis in astrocytes may contribute to the severe neuropathogenesis in clade B infection. PMID:23620748

Atluri, Venkata Subba Rao; Kanthikeel, Sudheesh P.; Reddy, Pichili V. B.; Yndart, Adriana; Nair, Madhavan P. N.

2013-01-01

270

Lessons Learned Developing a Diagnostic Tool for HIV-Associated Dementia Feasible to Implement in Resource-Limited Settings: Pilot Testing in Kenya  

PubMed Central

Objective To conduct a preliminary evaluation of the utility and reliability of a diagnostic tool for HIV-associated dementia (HAD) for use by primary health care workers (HCW) which would be feasible to implement in resource-limited settings. Background In resource-limited settings, HAD is an indication for anti-retroviral therapy regardless of CD4 T-cell count. Anti-retroviral therapy, the treatment for HAD, is now increasingly available in resource-limited settings. Nonetheless, HAD remains under-diagnosed likely because of limited clinical expertise and availability of diagnostic tests. Thus, a simple diagnostic tool which is practical to implement in resource-limited settings is an urgent need. Methods A convenience sample of 30 HIV-infected outpatients was enrolled in Western Kenya. We assessed the sensitivity and specificity of a diagnostic tool for HAD as administered by a primary HCW. This was compared to an expert clinical assessment which included examination by a physician, neuropsychological testing, and in selected cases, brain imaging. Agreement between HCW and an expert examiner on certain tool components was measured using Kappa statistic. Results The sample was 57% male, mean age was 38.6 years, mean CD4 T-cell count was 323 cells/µL, and 54% had less than a secondary school education. Six (20%) of the subjects were diagnosed with HAD by expert clinical assessment. The diagnostic tool was 63% sensitive and 67% specific for HAD. Agreement between HCW and expert examiners was poor for many individual items of the diagnostic tool (K?=?.03–.65). This diagnostic tool had moderate sensitivity and specificity for HAD. However, reliability was poor, suggesting that substantial training and formal evaluations of training adequacy will be critical to enable HCW to reliably administer a brief diagnostic tool for HAD. PMID:22412945

Kwasa, Judith; Cettomai, Deanna; Lwanya, Edwin; Osiemo, Dennis; Oyaro, Patrick; Birbeck, Gretchen L.; Price, Richard W.; Bukusi, Elizabeth A.; Cohen, Craig R.; Meyer, Ana-Claire L.

2012-01-01

271

HIV-associated neurocognitive disorder in Australia: a case of a high-functioning and optimally treated cohort and implications for international neuroHIV research.  

PubMed

The Australian HIV-infected (HIV+) population is largely comprised of high-functioning men who have sex with men (MSM). Like other English-speaking countries, Australia mostly relies on US neuropsychological normative standards to detect and determine the prevalence of neurological disorders. Whether the US neuropsychological (NP) normative standards are appropriate in Australian HIV+ MSM has not been established. Ninety virally suppressed HIV+ and 49 HIV-uninfected (HIV-) men (respectively 86 and 85 % self-reported MSM; mean age 54 and 56 years, mean premorbid verbal IQ estimate 110 and 111) undertook standard NP testing. The raw neuropsychological data were transformed using the following: (1) US standards as uncorrected scaled scores and demographically corrected T scores (US norms); and (2) z scores (without demographic corrections) derived from Australian comparison group scaled scores (local norms). To determine HIV-associated neurocognitive disorder prevalence, we used a standard definition of impairment based upon a battery-wide summary score: the global deficit score (GDS). Impairment classification (GDS???0.5) based on the local norms was best at discriminating between the two groups (HIV-?=?14.3 % vs. HIV+?=?53.3 %; p?

Cysique, Lucette A; Heaton, Robert K; Kamminga, Jody; Lane, Tammy; Gates, Thomas M; Moore, Danielle M; Hubner, Emma; Carr, Andrew; Brew, Bruce J

2014-06-01

272

Antifungal activities of extracts from Thai medicinal plants against opportunistic fungal pathogens associated with AIDS patients.  

PubMed

Summary In this study, 36 extracts derived from 10 plant species were selected to screen for their antifungal activity against clinical isolates of Candida albicans, Cryptococcus neoformans and Microsporum gypseum. Selection was based on their use by traditional Thai healers or their reported antimicrobial activities in an attempt to find bioactive medicines for use in the treatment of opportunistic fungal infections in AIDS patients. The disc diffusion and hyphal extension-inhibition assays were primarily used to test for inhibition of growth. Minimum inhibitory concentration was determined by dilution methods. The chloroform extracts of Alpinia galanga and Boesenbergia pandurata had pronounced antifungal activity against C. neoformans and M. gypseum, but exhibited weak activity against C. albicans. Alpinia galanga and B. pandurata are excellent candidates for the development of a remedy for opportunistic fungal infections in AIDS patients. PMID:16115104

Phongpaichit, Souwalak; Subhadhirasakul, Sanan; Wattanapiromsakul, Chatchai

2005-09-01

273

[Mycolic acids--potential biomarkers of opportunistic infections caused by bacteria of the suborder Corynebacterineae].  

PubMed

Mycolic acids are one of the basic elements of the cell wall structure of bacteria belonging to the suborder Corynebacterineae, constituting from 20% to 40% of dry weight. Additionally, they show high structural diversity within each family and species. Nowadays, profiles of mycolic acids are widely described for the genus Mycobacterium, the causative agent of tuberculosis. However, the suborder Corynebacterineae also includes many representatives of opportunistic human pathogens, e.g. Dietzia, Gordonia, Nocardia and Rhodococcus. Currently, an increased infection risk caused by this group of microorganisms especially in immunocompromised patients has been observed. Better knowledge of mycolic acid profiles for Corynebacterineae may allow identification of mycolic acids as diagnostic markers in the detection of opportunistic bacterial infections. Modern techniques of chemical analysis, including mass spectrometry, may enable the development of new chemotaxonomic methods for the detection and differentiation of bacteria within the suborder Corynebacterineae. PMID:22922146

Kowalski, Konrad; Szewczyk, Rafa?; Druszczy?ska, Magdalena

2012-01-01

274

On Optimal Control for Opportunistic Spectrum Access of Cognitive Radio Networks  

Microsoft Academic Search

The listen-Before-Talk (LBT) strategy has been prevalent in cognitive radio networks where secondary users opportunistically access under-utilized primary band. To min- imize the amount of disruption from secondary users to primary signals, secondary users generally are required to detect the presence of the primary user reliably, and access the spectrum intelligently. The sensing time has to be long enough to

Senhua Huang; Xin Liu; Zhi Ding

275

Distributed spectrum sensing and channel selection in opportunistic wireless personal area networks  

Microsoft Academic Search

This demonstrator showcases a distributed spectrum sensing and channel selection service running on a small-scale IEEE 802.15.4 opportunistic WPAN network. This service can provide spectrum awareness to the network itself or to other co-located networks. In case an interfering signal is detected the network devices are able to identify less used spectrum portions such that the network can reallocate to

Hussein Khaleel; Federico Penna; Claudio Pastrone; Riccardo Tomasi; Maurizio Spirito

2010-01-01

276

Opportunistic immunisation of paediatric inpatients at Rotorua Hospital: audit and discussion  

Microsoft Academic Search

Aim To audit current practice around opportunistic immunisation in a New Zealand hospital and make recommendations for improvement. Methods We reviewed inpatient notes for 369 patients aged 3-23 months admitted over a 6-month period in 2007. Data was obtained regarding children's immunisation status, documentation of this and action taken in response to the under-immunised child. Literature review and discussion with

Rowena Gilbert; Katharine Wrigley

277

Opportunistic Infections and Complications in Human Immunodeficiency Virus-1-Infected Children  

PubMed Central

Objectives: The aim of this study was to ascertain the correlation between various opportunistic infections and complications in human immunodeficiency virus (HIV)-1-infected children and the immune status of these patients, evaluated by absolute cluster of differentiation 4 (CD4) count and CD4 percentage. Methods: This study was conducted from January 2009 to June 2010 at the Antiretroviral Treatment Centre of the Pt. B.D. Sharma Post Graduate Institute of Medical Sciences, a tertiary care hospital in Rohtak, Haryana, in northern India. A total of 20 HIV-1-infected children aged 4–57 months were studied. Demographic and baseline investigations were performed prior to the start of highly active antiretroviral therapy (HAART). A fixed-dose combination of HAART was given based on the patient’s weight. Baseline investigations were repeated after six months of HAART. Results: There was a significant increase in the patients’ haemoglobin, weight, height and CD4 count after six months of HAART. Significant improvements (P <0.05) were also noted in the patients’ immune status, graded according to the World Health Organization. Conclusion: This study observed that the severity and frequency of opportunistic complications in paediatric patients with HIV-1 increased with a fall in the CD4 count. The treatment of opportunistic infections, along with antiretroviral therapy, may lead to both clinical and immunological recovery as well as a decreased incidence of future opportunistic infections. The CD4 count may give treating physicians an initial idea about the immune status of each child and could also be used as a biological marker of HAART efficacy. Patient compliance must be ensured during HAART as this is a key factor in improving outcomes.

Yadav, Jaivinder; Nanda, Sanjeev; Sharma, Deepak

2014-01-01

278

Declining prevalence of opportunistic gastrointestinal disease in the era of combination antiretroviral therapy  

Microsoft Academic Search

OBJECTIVE:Opportunistic disorders (OD) are the most frequent GI manifestations of the acquired immunodeficiency syndrome (AIDS). Since the introduction of highly active antiretroviral therapy (HAART), there appears to be have been a reduction in the incidence of many of these OD; however, the effect of HAART on the prevalence of GI OD has not been well studied.METHODS:From 4\\/95 through 3\\/98, all

Klaus E. Monkemuller; Stephanie A. Call; Audrey J. Lazenby; C. Mel Wilcox

2000-01-01

279

Opportunistic evolution: Abiotic environmental stress and the fossil record of plants  

Microsoft Academic Search

DiMichele, W.A., Phillips, T.L. and Olmstead, R.G., 1987. Opportunistic evolution: abiotic environmental stress and the fossil record of plants. Rev. Palaeobot. Palynol., 50: 151-178. Abiotic stress has played a major role in the evolution of vascular plants by creating or delimiting habitats with low interspecific competition. These are, in effect, opportunities for survival of divergent phenotypes through non- adaptive evolution.

WILLIAM A. DIMICHELE; TOM L. PHILLIPS; RICHARD G. OLMSTEAD

1987-01-01

280

Use of opportunistic clinical data and a population pharmacokinetic model to support dosing of clindamycin for premature infants to adolescents.  

PubMed

Clindamycin is commonly prescribed to treat children with skin and skin-structure infections (including those caused by community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA)), yet little is known about its pharmacokinetics (PK) across pediatric age groups. A population PK analysis was performed in NONMEM using samples collected in an opportunistic study from children receiving i.v. clindamycin per standard of care. The final model was used to optimize pediatric dosing to match adult exposure proven effective against CA-MRSA. A total of 194 plasma PK samples collected from 125 children were included in the analysis. A one-compartment model described the data well. The final model included body weight and a sigmoidal maturation relationship between postmenstrual age (PMA) and clearance (CL): CL (l/h) = 13.7 × (weight/70)(0.75) × (PMA(3.1)/(43.6(3.1) + PMA(3.1))); V (l) = 61.8 × (weight/70). Maturation reached 50% of adult CL values at ~44 weeks PMA. Our findings support age-based dosing. PMID:24949994

Gonzalez, D; Melloni, C; Yogev, R; Poindexter, B B; Mendley, S R; Delmore, P; Sullivan, J E; Autmizguine, J; Lewandowski, A; Harper, B; Watt, K M; Lewis, K C; Capparelli, E V; Benjamin, D K; Cohen-Wolkowiez, M

2014-10-01

281

Interactions between the tropical sea anemone Aiptasia pallida and Serratia marcescens, an opportunistic pathogen of corals.  

PubMed

Coral reefs are under increasing stress caused by global and local environmental changes, which are thought to increase the susceptibility of corals to opportunistic pathogens. In the absence of an easily culturable model animal, the understanding of the mechanisms of disease progression in corals remains fairly limited. In the present study, we tested the susceptibility of the tropical sea anemone Aiptasia pallida to an opportunistic coral pathogen (Serratia marcescens). A.?pallida was susceptible to S. marcescens?PDL100 and responded to this opportunistic coral pathogen with darkening of the tissues and retraction of tentacles, followed by complete disintegration of polyp tissues. Histological observations revealed loss of zooxanthellae and structural changes in eosinophilic granular cells in response to pathogen infection. A screen of S.?marcescens mutants identified a motility and tetrathionate reductase mutants as defective in virulence in the A.?pallida infection model. In co-infections with the wild-type strain, the tetrathionate reductase mutant was less fit within the surface mucopolysaccharide layer of the host coral Acropora palmata. PMID:24983533

Krediet, Cory J; Meyer, Julie L; Gimbrone, Nicholas; Yanong, Roy; Berzins, Ilze; Alagely, Ali; Castro, Herman; Ritchie, Kim B; Paul, Valerie J; Teplitski, Max

2014-06-01

282

The State of Disparities in Opportunistic Infection Prophylaxis for Blacks with HIV/AIDS  

PubMed Central

Objectives The purpose of this review is to identify and analyze published studies that have evaluated disparities for opportunistic infection (OI) prophylaxis between Blacks and Whites with HIV/AIDS in the United States. Methods The authors conducted a web-based search of MEDLINE (1950 to 2009) to identify original research articles evaluating the use of OI prophylaxis between Blacks and Whites with HIV/AIDS. The search was conducted utilizing the following MeSH headings and search terms alone and in combination: HIV, AIDS, Black, race, ethnicity, disparities, differences, access, opportunistic infection, and prophylaxis. The search was then expanded to include any relevant articles from the referenced citations of the articles that were retrieved from the initial search strategy. Of the 29 articles retrieved from the literature search, 19 articles were excluded. Results Ten publications met inclusion criteria, collectively published between 1991 and 2005. The collective time periods of these studies spanned from 1987 to 2001. Four studies identified a race-based disparity in that Blacks were less likely than Whites to use OI prophylaxis, whereas five studies failed to identify such a relationship between race and OI prophylaxis. One study identified disparities for Mycobacterium avium complex (MAC) prophylaxis, but not for Pneumocystis jiroveci pneumonia (PCP) prophylaxis. Conclusions The evidence regarding race-based disparities in opportunistic infection prophylaxis is inconclusive. Additional research is warranted to explore potential race-based disparities in OI prophylaxis. PMID:23047780

Oramasionwu, Christine U.; Koeller, Jim M.; Lawson, Kenneth A.; Brown, Carolyn M.; Morse, Gene D.; Frei, Christopher R.

2012-01-01

283

Invasion Ability and Disease Dynamics of Environmentally Growing Opportunistic Pathogens under Outside-Host Competition  

PubMed Central

Most theories of the evolution of virulence concentrate on obligatory host-pathogen relationship. Yet, many pathogens replicate in the environment outside-host where they compete with non-pathogenic forms. Thus, replication and competition in the outside-host environment may have profound influence on the evolution of virulence and disease dynamics. These environmentally growing opportunistic pathogens are also a logical step towards obligatory pathogenicity. Efficient treatment methods against these diseases, such as columnaris disease in fishes, are lacking because of their opportunist nature. We present a novel epidemiological model in which replication and competition in the outside-host environment influences the invasion ability of a novel pathogen. We also analyze the long-term host-pathogen dynamics. Model parameterization is based on the columnaris disease, a bacterial fresh water fish disease that causes major losses in fish farms worldwide. Our model demonstrates that strong competition in the outside-host environment can prevent the invasion of a new environmentally growing opportunist pathogen and long-term disease outbreaks. PMID:25415341

Merikanto, Ilona; Laakso, Jouni T.; Kaitala, Veijo

2014-01-01

284

Antifungal activity of synthetic naphthoquinones against dermatophytes and opportunistic fungi: preliminary mechanism-of-action tests.  

PubMed

This study evaluated the antifungal activities of synthetic naphthoquinones against opportunistic and dermatophytic fungi and their preliminary mechanisms of action. The minimum inhibitory concentrations (MICs) of four synthetic naphthoquinones for 89 microorganisms, including opportunistic yeast agents, dermatophytes and opportunistic filamentous fungi, were determined. The compound that exhibited the best activity was assessed for its action against the cell wall (sorbitol test), for interference associated with ergosterol interaction, for osmotic balance (K+ efflux) and for membrane leakage of substances that absorb at the wavelength of 260 nm. All tested naphthoquinones exhibited antifungal activity, and compound IVS320 (3a,10b-dihydro-1H-cyclopenta [b] naphtho [2,3-d] furan-5,10-dione)-dione) demonstrated the lowest MICs across the tested species. The MIC of IVS320 was particularly low for dermatophytes (values ranging from 5-28 ?g/mL) and Cryptococcus spp. (3-5 ?g/mL). In preliminary mechanism-of-action tests, IVS320 did not alter the fungal cell wall but did cause problems in terms of cell membrane permeability (efflux of K+ and leakage of substances that absorb at 260 nm). This last effect was unrelated to ergosterol interactions with the membrane. PMID:24998949

Ferreira, Maria do Perpetuo Socorro Borges Carriço; Cardoso, Mariana Filomena do Carmo; da Silva, Fernando de Carvalho; Ferreira, Vitor Francisco; Lima, Emerson Silva; Souza, João Vicente Braga

2014-01-01

285

Antifungal activity of synthetic naphthoquinones against dermatophytes and opportunistic fungi: preliminary mechanism-of-action tests  

PubMed Central

This study evaluated the antifungal activities of synthetic naphthoquinones against opportunistic and dermatophytic fungi and their preliminary mechanisms of action. The minimum inhibitory concentrations (MICs) of four synthetic naphthoquinones for 89 microorganisms, including opportunistic yeast agents, dermatophytes and opportunistic filamentous fungi, were determined. The compound that exhibited the best activity was assessed for its action against the cell wall (sorbitol test), for interference associated with ergosterol interaction, for osmotic balance (K+ efflux) and for membrane leakage of substances that absorb at the wavelength of 260 nm. All tested naphthoquinones exhibited antifungal activity, and compound IVS320 (3a,10b-dihydro-1H-cyclopenta [b] naphtho [2,3-d] furan-5,10-dione)-dione) demonstrated the lowest MICs across the tested species. The MIC of IVS320 was particularly low for dermatophytes (values ranging from 5–28 ?g/mL) and Cryptococcus spp. (3–5 ?g/mL). In preliminary mechanism-of-action tests, IVS320 did not alter the fungal cell wall but did cause problems in terms of cell membrane permeability (efflux of K+ and leakage of substances that absorb at 260 nm). This last effect was unrelated to ergosterol interactions with the membrane. PMID:24998949

2014-01-01

286

Symbiotic mutualism with a community of opportunistic ants: protection, competition, and ant occupancy of the myrmecophyte Barteria nigritana (Passifloraceae)  

Microsoft Academic Search

Barteria nigritana is a myrmecophyte tree of Lower Guinea coastal vegetation. Unlike the more specialised B. fistulosa, which harbours a single host-specific mutualistic ant, B. nigritana is associated with several opportunistic ants. Such symbiotic, yet opportunistic, ant–plant associations have been little studied. On 113 clumps of B. nigritana, we censused ant associates and herbivores and compared herbivory on plants occupied by

Champlain Djiéto-Lordon; Alain Dejean; Marc Gibernau; Martine Hossaert-McKey; Doyle McKey

2004-01-01

287

Isobaric tagging-based quantification by mass spectrometry of differentially regulated proteins in synaptosomes of HIV/gp120 transgenic mice: implications for HIV-associated neurodegeneration.  

PubMed

HIV/gp120 transgenic mice manifest neuropathological features similar to HIV-associated neurocognitive disorders (HAND) in humans, including astrogliosis, microglia activation, and decreased neuronal synapses. Here, proteomic screening of synaptosomes from HIV/gp120 transgenic mice was conducted to determine potential neuronal markers and drug targets associated with HAND. Synaptosomes from 13 month-old wild-type (wt) and HIV/gp120 transgenic mouse cortex were subjected to tandem mass tag (TMT) labeling and subsequent analysis using an LTQ-Orbitrap mass spectrometer in pulsed-Q dissociation (PQD) mode for tandem mass spectrometry (MS/MS). A total of 1301 proteins were identified in both wt and HIV/gp120 transgenic mice. Three of the most differentially-regulated proteins were validated by immunoblotting. To elucidate putative pathways associated with the proteomic profile, 107 proteins manifesting a ?1.5 fold change in expression were analyzed using a bioinformatics pathway analysis tool. This analysis revealed direct or indirect involvement of the phosphotidylinositol 3-kinase (PI3K)/protein kinase B (Akt) pathway, a well-known neuronal survival pathway. Immunoblots confirmed a lower phospho (p)Akt/Akt ratio in synaptosomes from HIV/gp120 transgenic animals compared to wt, suggesting that this neuroprotective pathway was inactivated in the HIV/gp120 transgenic brain. Based on this information, we then compared immunoblots of pAkt/Akt in the forebrains of these mice as well as in human postmortem brain. We observed a significant decrease in the pAkt/Akt ratio in synaptosomes and forebrain of HIV/gp120 transgenic compared to wt mice, and a similar decrease in human forebrain from HAND patients compared to neurologically unimpaired HIV+ and HIV- controls. Moreover, mechanistic insight into an additional pathway for decreased Akt activity in HIV/gp120 mouse brains and human HAND brains was shown to occur via S-nitrosylation of Akt protein, a posttranslational modification known to inhibit Akt activity and contribute to neuronal cell injury and death. Thus, MS proteomic profiling in the HIV/gp120 transgenic mouse predicted dysregulation of the PI3K/Akt pathway observed in human brains with HAND, providing evidence that this mouse is a useful disease model and that the Akt pathway may provide multiple drug targets for the treatment of HIV-related dementias. PMID:22575597

Banerjee, Sugato; Liao, Lujian; Russo, Rossella; Nakamura, Tomohiro; McKercher, Scott R; Okamoto, Shu-ichi; Haun, Florian; Nikzad, Rana; Zaidi, Rameez; Holland, Emily; Eroshkin, Alexey; Yates, John R; Lipton, Stuart A

2012-08-01

288

Cronobacter spp.--opportunistic food-borne pathogens. A review of their virulence and environmental-adaptive traits.  

PubMed

The genus Cronobacter consists of a diverse group of Gram-negative bacilli and comprises seven species: Cronobacter sakazakii, Cronobacter malonaticus, Cronobacter muytjensii, Cronobacter turicensis, Cronobacter dublinensis, Cronobacter universalis and Cronobacter condimenti. Cronobacter are regarded as opportunistic pathogens, and have been implicated in newborn and infant infections, causing meningitis, necrotizing enterocolitis and bacteraemia or sepsis. Cronobacter virulence is believed to be due to multiple factors. Some strains were found to produce diarrhoea or cause significant fluid accumulation in suckling mice. Two iron acquisition systems (eitCBAD and iucABCD/iutA), Cronobacter plasminogen activator gene (cpa), a 17 kb type VI secretion system (T6SS), and a 27 kb filamentous haemagglutinin gene (fhaBC) and associated putative adhesins locus are harboured on a family of RepFIB-related plasmids (pESA3 and pCTU1), suggesting that these are common virulence plasmids; 98% of 229 tested Cronobacter strains possessed these plasmids. Even though pESA3 and pCTU1 share a common backbone composed of the repA gene and eitCBAD and iucABCD/iutA gene clusters, the presence of cpa, T6SS and FHA loci depended on species, demonstrating a strong correlation with the presence of virulence traits, plasmid type and species. Other factors were observed, in that Cronobacter form biofilms, and show unusual resistance to heat, dry and acid stress growth conditions. The outer-membrane protein A is probably one of the best-characterized virulence markers of Cronobacter. Furthermore, it was reported that Cronobacter employ phosphatidylinositide 3-kinase/Akt signalling, which activates protein kinase C-? and impairs the host cell's mitogen-activated protein kinase pathway, in order to invade cells. Cronobacter can also use immature dendritic cells and macrophages to escape the immune response. This review addresses the various virulence and environmental-adaptive characteristics possessed by members of the genus Cronobacter. PMID:24878566

Jaradat, Ziad W; Al Mousa, Waseem; Elbetieha, Ahmed; Al Nabulsi, Anas; Tall, Ben D

2014-08-01

289

Stealing bivalves from common eiders: kleptoparasitism by glaucous gulls in spring  

Microsoft Academic Search

Here I report on glaucous gulls (Larus hyperboreus), an opportunistic, generalist predator, stealing bivalves from a diving duck, the common eider (Somateria mollissima). The study took place in spring, the pre-breeding period of the common eider, in an Arctic fjord (Adventfjorden) at western\\u000a Spitsbergen, Svalbard. Eiders were abundant, their presence predictable, and they fed on large prey requiring surface handling—all

Øystein Varpe

2010-01-01

290

A Case of an Acquired Factor VIII Inhibitor Complicated by Multiple Treatment-Related Opportunistic Infections and Review of the Literature  

PubMed Central

This case report describes a patient with an idiopathic acquired Factor VIII inhibitor and severe bleeding. She was treated with rituximab after failing first-line treatment with steroids and cyclophosphamide. Two months following rituximab treatment, our patient developed a succession of severe opportunistic infections requiring intensive care unit admission. Over a period of 12 weeks she required treatment for Pseudomonas aeruginosa septicaemia, herpes simplex gingivostomatitis and pharyngotonsillitis, clostridium difficile-related diarrhoea, systemic cytomegalovirus infection, pneumocystis jiroveci, and invasive pulmonary aspergillosis lung infections. After significant rehabilitation, the patient was finally discharged following a 5-month admission. This case highlights the complexity of balancing a life-threatening condition with the side effects of treatment. It also raises the issue of routine prophylaxis for immunosuppression in nonmalignant conditions, which will become a common dilemma with the expanding indications for rituximab use. PMID:24455336

Hutchinson, Anna L.

2013-01-01

291

Regrowth of potential opportunistic pathogens and algae in reclaimed-water distribution systems.  

PubMed

A study of the quality of reclaimed water in treated effluent, after storage, and at three points in the distribution system of four plants in California, Florida, Massachusetts, and New York was conducted for 1 year. The plants had different treatment processes (conventional versus membrane bioreactor), production capacities, and methods for storage of the water, and the intended end uses of the water were different. The analysis focused on the occurrence of indicator bacteria (heterotrophic bacteria, coliforms, Escherichia coli, and enterococci) and opportunistic pathogens (Aeromonas spp., enteropathogenic E. coli O157:H7, Legionella spp., Mycobacterium spp., and Pseudomonas spp.), as well as algae. Using immunological methods, E. coli O157:H7 was detected in the effluent of only one system, but it was not detected at the sampling points, suggesting that its survival in the system was poor. Although all of the treatment systems effectively reduced the levels of bacteria in the effluent, bacteria regrew in the reservoir and distribution systems because of the loss of residual disinfectant and high assimilable organic carbon levels. In the systems with open reservoirs, algal growth reduced the water quality by increasing the turbidity and accumulating at the end of the distribution system. Opportunistic pathogens, notably Aeromonas, Legionella, Mycobacterium, and Pseudomonas, occurred more frequently than indicator bacteria (enterococci, coliforms, and E. coli). The Mycobacterium spp. were very diverse and occurred most frequently in membrane bioreactor systems, and Mycobacterium cookii was identified more often than the other species. The public health risk associated with these opportunistic pathogens in reclaimed water is unknown. Collectively, our results show the need to develop best management practices for reclaimed water to control bacterial regrowth and degradation of water before it is utilized at the point of use. PMID:20453149

Jjemba, Patrick K; Weinrich, Lauren A; Cheng, Wei; Giraldo, Eugenio; Lechevallier, Mark W

2010-07-01

292

Mitochondrial Telomeres as Molecular Markers for Identification of the Opportunistic Yeast Pathogen Candida parapsilosis  

PubMed Central

Recent studies have demonstrated that a large number of organisms carry linear mitochondrial DNA molecules possessing specialized telomeric structures at their ends. Based on this specific structural feature of linear mitochondrial genomes, we have developed an approach for identification of the opportunistic yeast pathogen Candida parapsilosis. The strategy for identification of C. parapsilosis strains is based on PCR amplification of specific DNA sequences derived from the mitochondrial telomere region. This assay is complemented by immunodetection of a protein component of mitochondrial telomeres. The results demonstrate that mitochondrial telomeres represent specific molecular markers with potential applications in yeast diagnostics and taxonomy. PMID:11923346

Nosek, Jozef; Tomaska, L'ubomir; Rycovska, Adriana; Fukuhara, Hiroshi

2002-01-01

293

Anticipating challenges with in-building disinfection for control of opportunistic pathogens.  

PubMed

A new American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) standard for control of Legionella (ASHRAE Standard 188, 2013) emphasizes use of in-building disinfection techniques to reduce the exposure of at-risk consumers to opportunistic pathogens in premise plumbing (OPPPs). This standard and other recommendations for OPPP control have implications for scaling in and corrosion of plumbing systems, which can sometimes adversely affect the efficacy of the disinfection method and physical integrity of the plumbing system, prompting this proactive critical review of challenges associated with implementation of Standard 188. PMID:25109200

Rhoads, William J; Pruden, Amy; Edwards, Marc A

2014-06-01

294

Recent trends in the spectrum of opportunistic infections in human immunodeficiency virus infected individuals on antiretroviral therapy in South India  

PubMed Central

Background: Opportunistic infections (OI) are the major cause of morbidity and mortality among human immunodeficiency virus (HIV) infected individuals. The pattern of OIs differs widely, hence it is necessary to correlate spectrum of OIs and CD4 counts among HIV infected individuals in specific localities. Materials and Methods: The present study describes the clinical and laboratory profiles of different OIs among 55 HIV seropositive patients. CD4 count was estimated and antiretroviral therapy (ART) was started in 27 patients as per National Acquired Immunodeficiency Syndrome Control Organization guidelines. These 27 patients were classified into stage 1, stage 2 and stage 3 based on CD4 counts of >500 cells/?l, 200-499 cells/?l and <200 cells/?l respectively. The OIs presented by respective groups were documented. Results: Pulmonary tuberculosis was found to be the most common OI constituting 43.6% of all cases followed by candidiasis (30.9%), cryptosporidial diarrhea (21.8%), herpes zoster (16.3%), cryptococcal meningitis (3.63%), Pneumocystis jirovecii pneumonia (1.81%), and other miscellaneous infections (23.6%). Only 1 patient was found in stage I while 13 patients each were grouped in stage II or stage III. The mean CD4 count in our study population who were on ART was 230 ± 150 cells/µl. Conclusion: The pattern of OIs among our study group did not differ significantly from patients not receiving ART. The effect of ART on CD4 count differs from patient to patient based on the degree of depletion of CD4 count before the initiation of ART, drug adherence, concomitant OIs and their treatment. PMID:25097422

Shahapur, Praveen R.; Bidri, Rajendra C.

2014-01-01

295

AsrR Is an Oxidative Stress Sensing Regulator Modulating Enterococcus faecium Opportunistic Traits, Antimicrobial Resistance, and Pathogenicity  

PubMed Central

Oxidative stress serves as an important host/environmental signal that triggers a wide range of responses in microorganisms. Here, we identified an oxidative stress sensor and response regulator in the important multidrug-resistant nosocomial pathogen Enterococcus faecium belonging to the MarR family and called AsrR (antibiotic and stress response regulator). The AsrR regulator used cysteine oxidation to sense the hydrogen peroxide which results in its dissociation to promoter DNA. Transcriptome analysis showed that the AsrR regulon was composed of 181 genes, including representing functionally diverse groups involved in pathogenesis, antibiotic and antimicrobial peptide resistance, oxidative stress, and adaptive responses. Consistent with the upregulated expression of the pbp5 gene, encoding a low-affinity penicillin-binding protein, the asrR null mutant was found to be more resistant to ?-lactam antibiotics. Deletion of asrR markedly decreased the bactericidal activity of ampicillin and vancomycin, which are both commonly used to treat infections due to enterococci, and also led to over-expression of two major adhesins, acm and ecbA, which resulted in enhanced in vitro adhesion to human intestinal cells. Additional pathogenic traits were also reinforced in the asrR null mutant including greater capacity than the parental strain to form biofilm in vitro and greater persistance in Galleria mellonella colonization and mouse systemic infection models. Despite overexpression of oxidative stress-response genes, deletion of asrR was associated with a decreased oxidative stress resistance in vitro, which correlated with a reduced resistance to phagocytic killing by murine macrophages. Interestingly, both strains showed similar amounts of intracellular reactive oxygen species. Finally, we observed a mutator phenotype and enhanced DNA transfer frequencies in the asrR deleted strain. These data indicate that AsrR plays a major role in antimicrobial resistance and adaptation for survival within the host, thereby contributes importantly to the opportunistic traits of E. faecium. PMID:22876178

Lebreton, Francois; van Schaik, Willem; Sanguinetti, Maurizio; Posteraro, Brunella; Torelli, Riccardo; Le Bras, Florian; Verneuil, Nicolas; Zhang, Xinglin; Giard, Jean-Christophe; Dhalluin, Anne; Willems, Rob J. L.; Leclercq, Roland; Cattoir, Vincent

2012-01-01

296

Striatal dopamine D2-like receptor correlation patterns with human obesity and opportunistic eating behavior.  

PubMed

The obesity epidemic is believed to be driven by a food environment that promotes consumption of inexpensive, convenient, high-calorie, palatable foods. Individual differences in obesity susceptibility or resistance to weight loss may arise because of alterations in the neurocircuitry supporting food reward and eating habits. In particular, dopamine signaling in the ventromedial striatum is thought to encode food reward and motivation, whereas dopamine in the dorsal and lateral striatum orchestrates the development of eating habits. We measured striatal dopamine D2-like receptor binding potential (D2BP) using positron emission tomography with [(18)F]fallypride in 43 human subjects with body mass indices (BMI) ranging from 18 to 45?kg?m(-)(2). Opportunistic eating behavior and BMI were both positively associated with D2BP in the dorsal and lateral striatum, whereas BMI was negatively associated with D2BP in the ventromedial striatum. These results suggest that obese people have alterations in dopamine neurocircuitry that may increase their susceptibility to opportunistic overeating while at the same time making food intake less rewarding, less goal directed and more habitual. Whether or not the observed neurocircuitry alterations pre-existed or occurred as a result of obesity development, they may perpetuate obesity given the omnipresence of palatable foods and their associated cues. PMID:25199919

Guo, J; Simmons, W K; Herscovitch, P; Martin, A; Hall, K D

2014-10-01

297

A study of young peoples' attitudes to opportunistic Chlamydia testing in UK general practice  

PubMed Central

Objective The objective of this study was to assess young people's perceptions of being offered a chlamydia screening test in United Kingdom (UK) general practice. Methods This is qualitative study that uses focus groups and individual interviews with young adults (age 16 – 18) to assess their views. Results These young adults were a difficult group to gain access to. Two focus groups, one in a school, the other in a general practice (family practice), and 2 individual interviews were undertaken (total sample 18). Respondents were unfamiliar with Chlamydia, but broadly aware of sexually transmitted infections. General practice (family practice) was perceived as an acceptable place to deliver opportunistic screening, but participants felt that tests should not be initiated by GP receptionists. Novel delivery routes such as schools and "Pub"/Bar dispensing machines were discussed. Issues around stigma and confidentiality were also raised. Conclusion Opportunistic Chlamydia screening in UK general practice (family practic seems acceptable to young adults. While this is a difficult group to gain access to for research, attempts need to made to ensure acceptability to users of this programme. PMID:19099571

Heritage, Joanne; Jones, Melvyn

2008-01-01

298

Heavy Metal Distribution in Opportunistic Beach Nourishment: A Case Study in Greece  

PubMed Central

The existence and distribution of persistent pollutants, such as heavy metals, in coastal sediment used for opportunistic beach nourishment, is a problem that has not received much attention. Here, we assessed the coastal sediments in one restoration project for the occurrence and distribution of heavy metals, by utilizing an Energy Dispersive X-Ray Fluorescence (EDXRF) system. Heavy metal point sources included (i) the effluents of small industries (tanneries), (ii) wastewater treatment plant effluents, and (iii) paint and oil scraps from substandard ship maintenance activities that take place on ports breakwaters. A few neighboring beaches were found to have similar heavy metal concentrations, with mean values of Cu, Zn, and Pb ranging from 80 to 130, 15 to 25, and 25 to 40?mg/kg, respectively. Existing legislation regarding dredging activities in Greece appears insufficient for sustainable and environmentally friendly nourishment. We conclude that before opportunistic beach restoration projects materialize with material borrowed from ports and harbors the quality of the dredged material needs to be assessed. PMID:24379742

Kallithrakas-Kontos, Nikolaos G.; Synolakis, Costas

2013-01-01

299

Isolation of Cryptococcus neoformans and other opportunistic fungi from pigeon droppings  

PubMed Central

Background: Invasive fungal infections cause considerable morbidity and mortality in immunocompromised hosts. Pigeon droppings could especially be a potential carrier in the spread of pathogenic yeasts and mold fungi into the environment. The objective of this study was to isolation of Cryptococcus neoformans and other opportunistic fungi from pigeon droppings. Materials and Methods: One hundred twenty samples of pigeon droppings were suspended 1:10 in saline solution and then cultured. Identification of C. neoformans was performed on bird seed agar, presence of a capsule on India ink preparation, urease production on urea agar medium and RapID yeast plus system. The identification of candida species was based on micro-morphological analysis on corn meal-Tween 80 agar, RapID yeast plus system and growth in CHROMagar candida. The identification of other fungi was based on macromorphologic, microscopic, biochemical and physiological characteristics. Results: The highest frequency of yeasts and mold fungi were observed in Candida albicans 6.6% and Penicillium spp. 25%. The frequency rate of C. neoformans isolation was 2.5%. Conclusion: Several types of fungi are present in pigeon droppings that can spread in environment and transmit to children and elderly as well as immunocompromised patients who are at increased risk of contracting opportunistic diseases. PMID:23901339

Soltani, Maryam; Bayat, Mansour; Hashemi, Seyed J.; Zia, Mohammadali; Pestechian, Nader

2013-01-01

300

Allelopathic Interactions between the Opportunistic Species Ulva prolifera and the Native Macroalga Gracilaria lichvoides  

PubMed Central

Allelopathy, one type of direct plant competition, can be a potent mechanism through which plant communities are structured. The aim of this study was to determine whether allelopathic interactions occur between the opportunistic green tide-forming species Ulva prolifera and the native macroalga Gracilaria lichvoides, both of which were collected from the coastline of East China sea. In laboratory experiments, the presence of G. lichvoides at 1.25 g wet weight L?1 significantly inhibited growth and photosynthesis of U. prolifera at concentrations of 1.25, 2.50, and 3.75 g wet weight L?1 (p<0.05) in both semi-continuous co-culture assays and in co-culture assays without nutrient supplementation. In contrast, although U. prolifera had a density effect on G. lichvoides, the differences among treatments were not significant (p>0.05). Culture medium experiments further confirmed that some allelochemicals may be released by both of the tested macroalgae, and these could account for the observed physiological inhibition of growth and photosynthesis. Moreover, the native macroalgae G. lichvoides was a stronger competitor than the opportunistic species U. prolifera. Collectively, the results of the present study represent a significant advance in exploring ecological questions about the effects of green tide blooms on the macroalgal community. PMID:22496758

Zhang, Xiaowen; Fan, Xiao; Wang, Yitao; Li, Demao; Wang, Wei; Zhuang, Zhimeng; Ye, Naihao

2012-01-01

301

Coping with the extremes: stress physiology varies between winter and summer in breeding opportunists.  

PubMed

Seasonal changes in stress steroid hormone secretions are thought to reflect investment in self-maintenance versus reproduction. The capricious conditions hypothesis (CCH) posits that reduced corticosterone (CORT) secretion during stress coincident with parental phases of breeding is necessary in harsh environments because a full response would otherwise trigger repeated nest abandonments. To test this hypothesis, we measured seasonal changes in stress physiology in free-living red crossbills (Loxia curvirostra), an opportunistically breeding songbird that regularly breeds in summer and winter. This species allows unique comparisons of breeding physiology under very different seasonal environmental conditions within locations. We found strong support for the CCH: red crossbills showed reduced CORT secretion only when in high reproductive condition in the winter, when compared with summer breeders and winter non-breeders. These data demonstrate that behavioural status and local environmental conditions interact to affect mechanisms underlying investment trade-offs, presumably in a way that maximizes lifetime reproductive success. PMID:22012950

Cornelius, Jamie M; Breuner, Creagh W; Hahn, Thomas P

2012-04-23

302

Cronobacter: an emerging opportunistic pathogen associated with neonatal meningitis, sepsis and necrotizing enterocolitis.  

PubMed

Members of the genus Cronobacter are an emerging group of opportunist Gram-negative pathogens. This genus was previously thought to be a single species, called Enterobacter sakazakii. Cronobacter spp. typically affect low-birth-weight neonates, causing life-threatening meningitis, sepsis and necrotizing enterocolitis. Outbreaks of disease have been associated with contaminated infant formula, although the primary environmental source remains elusive. Advanced understanding of these bacteria and better classification has been obtained by improved detection techniques and genomic analysis. Research has begun to characterize the virulence factors and pathogenic potential of Cronobacter. Investigations into sterilization techniques and protocols for minimizing the risk of contamination have been reviewed at national and international forums. In this review, we explore the clinical impact of Cronobacter neonatal and pediatric infections, discuss virulence and pathogenesis, and review prevention and treatment strategies. PMID:23538645

Hunter, C J; Bean, J F

2013-08-01

303

A Study of Trade-off between Opportunistic Resource Allocation and Interference Alignment in Femtocell Scenarios  

E-print Network

One of the main problems in wireless heterogeneous networks is interference between macro- and femto-cells. Using Orthogonal Frequency-Division Multiple Access (OFDMA) to create multiple frequency orthogonal sub-channels, this interference can be completely avoided if each sub-channel is exclusively used by either macro- or a femto-cell. However, such an orthogonal allocation may be inefficient. We consider two alternative strategies for interference management, opportunistic resource allocation (ORA) and interference alignment (IA). Both of them utilize the fading fluctuations across frequency channels in different ways. ORA allows the users to interfere, but selecting the channels where the interference is faded, while the desired signal has a good channel. IA uses precoding to create interference-free transmissions; however, such a precoding changes the diversity picture of the communication resources. In this letter we investigate the interactions and the trade-offs between these two strategies.

Lertwiram, Namzilp; Sakaguchi, Kei

2012-01-01

304

Vegetable microbiomes: is there a connection among opportunistic infections, human health and our 'gut feeling'?  

PubMed

The highly diverse microbiomes of vegetables are reservoirs for opportunistic and emerging pathogens. In recent years, an increased consumption, larger scale production and more efficient distribution of vegetables together with an increased number of immunocompromised individuals resulted in an enhanced number of documented outbreaks of human infections associated with the consumption of vegetables. Here we discuss the occurrence of potential pathogens in vegetable microbiomes, the impact of farming and processing practices, and plant and human health issues. Based on these results, we discuss the question if vegetables can serve as a source of infection for immunocompromised individuals as well as possible solutions to avoid outbreaks. Moreover, the potentially positive aspects of the vegetables microbiome for the gut microbiota and human health are presented. PMID:25186140

Berg, Gabriele; Erlacher, Armin; Smalla, Kornelia; Krause, Robert

2014-11-01

305

Vibrio vulnificus biotype 2, pathogenic for eels, is also an opportunistic pathogen for humans.  

PubMed Central

We report that the eel pathogen Vibrio vulnificus biotype 2 is also an opportunistic pathogen for humans. Results from a detailed comparative study using reference strains of both biotypes revealed that the clinical strain ATCC 33817, originally isolated from a human leg wound and classified as V. vulnificus (no reference on its biotype is noted), belongs to biotype 2 of the species. As a biotype 2 strain, it is negative for indole and pathogenic for eels and mice, harbors two plasmids of high MrS, and belongs to serogroup E, recently proposed as characteristic of biotype 2 strains. In consequence, appropriate measures must be taken by consumers, particularly by those running a health risk, and by fish farmers, above all when manipulating eels during epizootic outbreaks. PMID:8919812

Amaro, C; Biosca, E G

1996-01-01

306

Coping with the extremes: stress physiology varies between winter and summer in breeding opportunists  

PubMed Central

Seasonal changes in stress steroid hormone secretions are thought to reflect investment in self-maintenance versus reproduction. The capricious conditions hypothesis (CCH) posits that reduced corticosterone (CORT) secretion during stress coincident with parental phases of breeding is necessary in harsh environments because a full response would otherwise trigger repeated nest abandonments. To test this hypothesis, we measured seasonal changes in stress physiology in free-living red crossbills (Loxia curvirostra), an opportunistically breeding songbird that regularly breeds in summer and winter. This species allows unique comparisons of breeding physiology under very different seasonal environmental conditions within locations. We found strong support for the CCH: red crossbills showed reduced CORT secretion only when in high reproductive condition in the winter, when compared with summer breeders and winter non-breeders. These data demonstrate that behavioural status and local environmental conditions interact to affect mechanisms underlying investment trade-offs, presumably in a way that maximizes lifetime reproductive success. PMID:22012950

Cornelius, Jamie M.; Breuner, Creagh W.; Hahn, Thomas P.

2012-01-01

307

Temperature-dependent inhibition of opportunistic Vibrio pathogens by native coral commensal bacteria.  

PubMed

Bacteria living within the surface mucus layer of corals compete for nutrients and space. A number of stresses affect the outcome of this competition. The interactions between native microorganisms and opportunistic pathogens largely determine the coral holobiont's overall health and fitness. In this study, we tested the hypothesis that commensal bacteria isolated from the mucus layer of a healthy elkhorn coral, Acropora palmata, are capable of inhibition of opportunistic pathogens, Vibrio shiloi AK1 and Vibrio coralliilyticus. These vibrios are known to cause disease in corals and their virulence is temperature dependent. Elevated temperature (30 °C) increased the cell numbers of one commensal and both Vibrio pathogens in monocultures. We further tested the hypothesis that elevated temperature favors pathogenic organisms by simultaneously increasing the fitness of vibrios and decreasing the fitness of commensals by measuring growth of each species within a co-culture over the course of 1 week. In competition experiments between vibrios and commensals, the proportion of Vibrio spp. increased significantly under elevated temperature. We finished by investigating several temperature-dependent mechanisms that could influence co-culture differences via changes in competitive fitness. The ability of Vibrio spp. to utilize glycoproteins found in A. palmata mucus increased or remained stable when exposed to elevated temperature, while commensals' tended to decrease utilization. In both vibrios and commensals, protease activity increased at 30 °C, while chiA expression increased under elevated temperatures for Vibrio spp. These results provide insight into potential mechanisms through which elevated temperature may select for pathogenic bacterial dominance and lead to disease or a decrease in coral fitness. PMID:24370863

Frydenborg, Beck R; Krediet, Cory J; Teplitski, Max; Ritchie, Kim B

2014-02-01

308

The role and regulation of catalase in respiratory tract opportunistic bacterial pathogens.  

PubMed

Respiratory tract bacterial pathogens are the etiologic agents of a variety of illnesses. The ability of these bacteria to cause disease is imparted through survival within the host and avoidance of pathogen clearance by the immune system. Respiratory tract pathogens are continually bombarded by reactive oxygen species (ROS), which may be produced by competing bacteria, normal metabolic function, or host immunological responses. In order to survive and proliferate, bacteria have adapted defense mechanisms to circumvent the effects of ROS. Bacteria employ the use of anti-oxidant enzymes, catalases and catalase-peroxidases, to relieve the effects of the oxidative stressors to which they are continually exposed. The decomposition of ROS has been shown to provide favorable conditions in which respiratory tract opportunistic bacterial pathogens such as Haemophilus influenzae, Mycobacterium tuberculosis, Legionella pneumophila, and Neisseria meningitidis are able to withstand exposure to highly reactive molecules and yet survive. Bacteria possessing mutations in the catalase gene have a decreased survival rate, yet may be able to compensate for the lack of catalatic activity if peroxidatic activity is present. An incomplete knowledge of the mechanisms by which catalase and catalase-peroxidases are regulated still persists, however, in some bacterial species, a regulatory factor known as OxyR has been shown to either up-regulate or down-regulate catalase gene expression. Yet, more research is still needed to increase the knowledge base in relation to this enzyme class. As with this review, we focus on major respiratory tract opportunistic bacterial pathogens in order to elucidate the function and regulation of catalases. The importance of the research could lead to the development of novel treatments against respiratory bacterial infections. PMID:25109939

Eason, Mia M; Fan, Xin

2014-09-01

309

Structural diversity and biological significance of glycosphingolipids in pathogenic and opportunistic fungi  

PubMed Central

Glycosphingolipids (GSLs) are ubiquitous membrane components and have key roles in biological systems, acting as second messengers or modulators of signal transduction by affecting several events, ranging from cell adhesion, cell growth, cell motility, regulation of apoptosis and cell cycle. Over the last 20 years our laboratory and other research groups determined the glycan and ceramide structures of more than 20 GSLs from several pathogenic/opportunistic fungi, using a combination of gas chromatography, mass spectrometry, nuclear magnetic resonance as well as other immunochemical and biochemical techniques. Fungal GSLs can be divided in two major classes: neutral GSLs, galactosyl- and glucosylceramide (GlcCer), and acidic GSLs, the glycosylinositol-phosphorylceramides (GIPCs). Glycosyl structures in fungal GIPCs exhibited significant structural diversity and distinct composition when compared to mammalian GSLs, e.g., the expression of inositol-mannose and inositol-glucosamine cores and the terminal residue of ?-D-galactofuranose which are absent in mammalian cells. Studies performed by our group demonstrated that GIPC (Galf? 6[Man?3]Man?2InsPCer) elicited in patients with paracoccidioidomycosis an immune response with production of antibodies directed to the terminal residue of ?-D-galactofuranose. Further studies also showed that inhibition of GlcCer biosynthetic pathways affects fungal colony formation, spore germination and hyphal growth, indicating that enzymes involved in GlcCer biosynthesis may represent promising targets for the therapy of fungal infections. Recently, it was shown that GlcCer and GIPCs are preferentially localized in membrane microdomains and monoclonal antibodies directed to these GSLs interfere in several fungal biological processes such as growth and morphological transition. This review focuses on glycan structures carried on sphingolipids of pathogenic/opportunistic fungi, and aspects of their biological significance are discussed. PMID:25309884

Guimaraes, Luciana L.; Toledo, Marcos S.; Ferreira, Felipe A. S.; Straus, Anita H.; Takahashi, Helio K.

2014-01-01

310

Common Conditions in Newborns  

MedlinePLUS

... Baby > Common Conditions in Newborns Ages & Stages Listen Common Conditions in Newborns Article Body Some physical conditions are especially common during the first couple of weeks after birth. ...

311

Position statement on opportunistic genomic screening from the Association of Genetic Nurses and Counsellors (UK and Ireland).  

PubMed

The American College of Medical Genetics and Genomics released recommendations for reporting incidental findings (IFs) in clinical exome and genome sequencing. These suggest 'opportunistic genomic screening' should be available to both adults and children each time a sequence is done and would be undertaken without seeking preferences from the patient first. Should opportunistic genomic screening be implemented in the United Kingdom, the Association of Genetic Nurses and Counsellors (AGNC), which represents British and Irish genetic counsellors and nurses, feels strongly that the following must be considered (see article for complete list): (1) Following appropriate genetic counselling, patients should be allowed to consent to or opt out of opportunistic genomic screening. (2) If true IFs are discovered the AGNC are guided by the report from the Joint Committee on Medical Genetics about the sharing of genetic testing results. (3) Children should not be routinely tested for adult-onset conditions. (4) The formation of a list of variants should involve a representative from the AGNC as well as a patient support group. (5) The variants should be for serious or life-threatening conditions for which there are treatments or preventative strategies available. (6) There needs to be robust evidence that the benefits of opportunistic screening outweigh the potential harms. (7) The clinical validity and utility of variants should be known. (8) There must be a quality assurance framework that operates to International standards for laboratory testing. (9) Psychosocial research is urgently needed in this area to understand the impact on patients. PMID:24398792

Middleton, Anna; Patch, Chris; Wiggins, Jennifer; Barnes, Kathy; Crawford, Gill; Benjamin, Caroline; Bruce, Anita

2014-08-01

312

ERAD 2012 -THE SEVENTH EUROPEAN CONFERENCE ON RADAR IN METEOROLOGY AND HYDROLOGY On the opportunistic use of geostationary satellite  

E-print Network

On the opportunistic use of geostationary satellite signals to estimate rain rate in the purpose of radar calibration.barthes@latmos.ipsl.fr, cecile.mallet@latmos.ipsl.fr 15 April 2012 Rain gauge networks are often used for radar calibration al. (2006) and Leijnse et al. (2007) have shown that the path-integrated rain rate can be estimated

Boyer, Edmond

313

HUMAN IMMUNODEFICIENCY VIRUS (HIV) DISEASE OPPORTUNISTIC INFECTIONS IN PATIENTS WITH HIV AND AIDS Fungal and Parasitic Infections  

Microsoft Academic Search

A B S T R A C T : Since the advent of highly active anti- re t roviral therapy (HAART), the incidence of specific fungal and parasitic opportunistic infections as observed in HIVdisease has been in decline. However, in many parts of the world, and in areas where access to HAART is limited, these specific opport u n i

Jeffrey MARTINEZ; Zelalem TEMESGEN

314

Optimization of the machining economics problem for a multistage transfer machine under failure, opportunistic and integrated replacement strategies  

Microsoft Academic Search

In the extensive literature dealing with the machining economics problem, the optimization of the multistage production system is rarely discussed, and when so it is considered mostly in terms of the Failure Replacement Strategy. However, when analysing this problem, the possibility of using the Opportunistic or Integrated Replacement Strategies also arises. In this work, we minimize the expected cost per

M. Kaspi; D. Shabtay

2003-01-01

315

Cross-Layer Based Opportunistic MAC Protocols for QoS Provisionings Over Cognitive Radio Wireless Networks  

Microsoft Academic Search

We propose the cross-layer based opportunistic multi-channel medium access control (MAC) protocols, which integrate the spectrum sensing at physical (PHY) layer with the packets scheduling at MAC layer, for the wireless ad hoc networks. Specifically, the MAC protocols enable the secondary users to identify and utilize the leftover frequency spectrum in a way that constrains the level of interference to

Hang Su; Xi Zhang

2008-01-01

316

Up-Regulation of TLR2 and TLR4 in Dendritic Cells in Response to HIV Type 1 and Coinfection with Opportunistic Pathogens  

PubMed Central

Abstract The ability to trigger an innate immune response against opportunistic pathogens associated with HIV-1 infection is an important aspect of AIDS pathogenesis. Toll-like receptors (TLRs) play a critical role in innate immunity against pathogens, but in HIV-1 patients coinfected with opportunistic infections, the regulation of TLR expression has not been studied. In this context, we have evaluated the expression of TLR2 and TLR4 in monocytes, plasmacytoid dendritic cells, and myeloid dendritic cells of HIV-1 patients with or without opportunistic infections. Forty-nine HIV-1-infected individuals were classified according to viral load, highly active antiretroviral therapy (HAART), and the presence or absence of opportunistic infections, and 21 healthy subjects served as controls. Increased expression of TLR2 and TLR4 was observed in myeloid dendritic cells of HIV-1 patients coinfected with opportunistic infections (without HAART), while TLR4 increased in plasmacytoid dendritic cells, compared to both HIV-1 without opportunistic infections and healthy subjects. Moreover, TLR2 expression was higher in patients with opportunistic infections without HAART and up-regulation of TLR expression in HIV-1 patients coinfected with opportunistic infections was more pronounced in dendritic cells derived from individuals coinfected with Mycobacterium tuberculosis. The results indicate that TLR expression in innate immune cells is up-regulated in patients with a high HIV-1 load and coinfected with opportunistic pathogens. We suggest that modulation of TLRs expression represents a mechanism that promotes HIV-1 replication and AIDS pathogenesis in patients coinfected with opportunistic pathogens. PMID:21406030

Arteaga, Jose; Paul, Stéphane; Kumar, Ajit; Latz, Eicke; Urcuqui-Inchima, Silvio

2011-01-01

317

REVISITING COMMONS – ARE COMMON PROPERTY REGIMES IRRATIONAL?  

Microsoft Academic Search

This paper revisits the debate about communal management of natural resources and brings together various issues confronting it. Much of the criticism against common property regimes stems from an incorrect modeling of a common property situation, and misunderstandings about the terms and their wrong usage. Models of collective action (Hardin’s tragedy of the Commons, Olson’s Logic of Collective Action, and

Lubna Hasan

2002-01-01

318

Idiopathic CD4 Lymphocytopenia: Spectrum of opportunistic infections, malignancies, and autoimmune diseases  

PubMed Central

Idiopathic CD4 lymphocytopenia (ICL) was first defined in 1992 by the US Centers for Disease Control and Prevention (CDC) as the repeated presence of a CD4+ T lymphocyte count of fewer than 300 cells per cubic millimeter or of less than 20% of total T cells with no evidence of human immunodeficiency virus (HIV) infection and no condition that might cause depressed CD4 counts. Most of our knowledge about ICL comes from scattered case reports. The aim of this study was to collect comprehensive data from the previously published cases to understand the characteristics of this rare condition. We searched the PubMed database and Science Direct for case reports since 1989 for Idiopathic CD4 lymphocytopenia cases. We found 258 cases diagnosed with ICL in 143 published papers. We collected data about age, sex, pathogens, site of infections, CD4 count, CD8 count, CD4:CD8 ratio, presence of HIV risk factors, malignancies, autoimmune diseases and whether the patients survived or died. The mean age at diagnosis of first opportunistic infection (or ICL if no opportunistic infection reported) was 40.7 ± 19.2 years (standard deviation), with a range of 1 to 85. One-sixty (62%) patients were males, 91 (35.2%) were females, and 7 (2.7%) patients were not identified whether males or females. Risk factors for HIV were documented in 36 (13.9%) patients. The mean initial CD4 count was 142.6 ± 103.9/mm3 (standard deviation). The mean initial CD8 count was 295 ± 273.6/mm3 (standard deviation). The mean initial CD4:CD8 ratio was 0.6 ± 0.7 (standard deviation). The mean lowest CD4 count was 115.4 ± 87.1/mm3 (standard deviation). The majority of patients 226 (87.6%) had at least one infection. Cryptococcal infections were the most prevalent infections in ICL patients (26.6%), followed by mycobacterial infections (17%), candidal infections (16.2%), and VZV infections (13.1%). Malignancies were reported in 47 (18.1%) patients. Autoimmune diseases were reported in 37 (14.2%) patients. PMID:23930241

Ahmad, Dina S.; Esmadi, Mohammad; Steinmann, William C.

2013-01-01

319

A New Preadmission Staging System for Predicting Inpatient Mortality from HIV-associated Pneumocystis carinii Pneumonia in the Early Highly Active Antiretroviral Therapy (HAART) Era  

Microsoft Academic Search

A common severe complication of human immunodeficiency virus (HIV) infection has been Pneumocystis carinii pneumonia (PCP). Re- cently, with increasing use of PCP prophylaxis and multidrug anti- retroviral therapy, the clinical manifestations of HIV infection have changed dramatically and the predictors of inpatient mortality for PCP may have also changed. We developed a new staging system for predicting inpatient mortality

AHSAN M. AROZULLAH; PAUL R. YARNOLD; ROBERT A. WEINSTEIN; NDUKA NWADIARO; THOMAS B. M C ILRAITH; JOAN S. CHMIEL; ALISON M. SIPLER; CHEELING CHAN; MATTHEW B. GOETZ; DAVID N. SCHWARTZ; CHARLES L. BENNETT

320

Substance Abuse, Hepatitis C, and Aging in HIV: Common Cofactors that Contribute to Neurobehavioral Disturbances  

PubMed Central

Although the prevalence of neurocognitive disturbances among individuals with HIV has decreased in recent years, rates of impairment still remain high. This review presents findings from comorbid conditions that may contribute to further neurocognitive impairments in this already vulnerable population. We will focus on three co-factors that have received substantial attention in the neuroAIDS literature: drug use, hepatitis C co-infection (HCV), and aging. All three conditions commonly co-occur with HIV and likely interact with HIV in complex ways. Collectively, the extant literature suggests that drug use, HCV, and aging serve to worsen the neurocognitive profile of HIV through several overlapping mechanisms. A better understanding of how specific comorbidities interact with HIV may reveal specific phenotypes of HIV-associated neurocognitive disorder that may aid in the development of more targeted behavioral and pharmacological treatment efforts. PMID:24014165

Schuster, Randi Melissa; Gonzalez, Raul

2013-01-01

321

Opportunistic out-crossing in Nicotiana attenuata (Solanaceae), a predominantly self-fertilizing native tobacco  

PubMed Central

Background Although Nicotiana attenuata is entirely self-compatible, chemical and other floral traits suggest selection for the maintenance of advertisement for moth pollinators. Results Experimental exclusions of pollinators from plants with emasculated flowers in natural populations in southern Utah during an outbreak of the hawkmoth Hyles lineata revealed that 24% of the seed set could be attributed to insect pollination, and eliminated wind pollination and apomixis as contributing to seed set. Hence these moths can mediate gene flow when self-pollen is unavailable. To quantify gene flow when self-pollen is available, plants were transformed with two marker genes: hygromycin-B resistance and ?-glucuronidase. The utility of these genetic markers to measure gene flow between plants was examined by mixing pollen from plants homozygous for both genes with self-pollen in different ratios and hand-pollinating emasculated flowers of plants growing in a natural population. The proportion of transformed seeds was positively correlated with the amount of transformed pollen applied to stigmas. In glasshouse experiments with the hawkmoth Manduca sexta and experimental arrays of transformed and wild-type plants, pollination mediated by moths accounted for 2.5% of the seed set. Conclusions Even though moth pollination is rare and highly variable for this largely selfing plant, N. attenuata opportunistically employs a mixed-mating system. PMID:12866951

Sime, Karen R; Baldwin, Ian T

2003-01-01

322

Global regulation of gene expression by OxyR in an important human opportunistic pathogen  

PubMed Central

Most bacteria control oxidative stress through the H2O2-responsive transactivator OxyR, a member of the LTTR family (LysR Type Transcriptional Regulators), which activates the expression of defensive genes such as those encoding catalases, alkyl hydroperoxide reductases and superoxide dismutases. In the human opportunistic pathogen Pseudomonas aeruginosa, OxyR positively regulates expression of the oxidative stress response genes katA, katB, ahpB and ahpCF. To identify additional targets of OxyR in P. aeruginosa PAO1, we performed chromatin immunoprecipitation in combination with whole genome tiling array analyses (ChIP-chip). We detected 56 genes including all the previously identified defensive genes and a battery of novel direct targets of OxyR. Electrophoretic mobility shift assays (EMSAs) for selected newly identified targets indicated that ?70% of those were bound by purified oxidized OxyR and their regulation was confirmed by quantitative real-time polymerase chain reaction. Furthermore, a thioredoxin system was identified to enzymatically reduce OxyR under oxidative stress. Functional classification analysis showed that OxyR controls a core regulon of oxidative stress defensive genes, and other genes involved in regulation of iron homeostasis (pvdS), quorum-sensing (rsaL), protein synthesis (rpsL) and oxidative phosphorylation (cyoA and snr1). Collectively, our results indicate that OxyR is involved in oxidative stress defense and regulates other aspects of cellular metabolism as well. PMID:22275523

Wei, Qing; Le Minh, Phu Nguyen; Dotsch, Andreas; Hildebrand, Falk; Panmanee, Warunya; Elfarash, Ameer; Schulz, Sebastian; Plaisance, Stephane; Charlier, Daniel; Hassett, Daniel; Haussler, Susanne; Cornelis, Pierre

2012-01-01

323

Development of a rapid detection system for opportunistic pathogenic Cronobacter spp. in powdered milk products.  

PubMed

Certain species of the genus Cronobacter are considered opportunistic pathogens, but their detection in milk products according to ISO/TS 22964 may take up to six days. The aim of this study was to develop a fast and sensitive PCR-based detection system for these species including enrichment, DNA-isolation and detection by real-time PCR, using the outer membrane protein gene ompA as a target. The assay was successfully validated using type strains of the genus Cronobacter, as well as 18 strains of closely related genera as controls. A total of 40 Cronobacter spp. food isolates yielded positive results, while the food matrix itself did not influence the PCR reaction. An equal detection limit as achieved with the ISO/TS 22964 method was established in this study, when 0.01 CFU Cronobacter sakazakii DSM 4485(T) per gram powdered infant formula were successfully detected after 28 days of storage at ambient temperature. In comparison to the ISO/TS 22964 method, the method described here has an equal detection limit, but offers a specific detection at the genus level in an analysis time of 24 h. PMID:24929712

Zimmermann, Jennifer; Schmidt, Herbert; Loessner, Martin J; Weiss, Agnes

2014-09-01

324

Studies of Opinion Stability for Small Dynamic Networks with Opportunistic Agents  

NASA Astrophysics Data System (ADS)

There are numerous examples of societies with extremely stable mix of contrasting opinions. We argue that this stability is a result of an interplay between society network topology adjustment and opinion changing processes. To support this position we present a computer model of opinion formation based on some novel assumptions, designed to bring the model closer to social reality. In our model, the agents, in addition to changing their opinions due to influence of the rest of society and external propaganda, have the ability to modify their social network, forming links with agents sharing the same opinions and cutting the links with those they disagree with. To improve the model further we divide the agents into "fanatics" and "opportunists," depending on how easy it is to change their opinions. The simulations show significant differences compared to traditional models, where network links are static. In particular, for the dynamical model where inter-agent links are adjustable, the final network structure and opinion distribution is shown to resemble real world observations, such as social structures and persistence of minority groups even when most of the society is against them and the propaganda is strong.

Sobkowicz, Pawel

325

Bioengineering T cells to target carbohydrate to treat opportunistic fungal infection.  

PubMed

Clinical-grade T cells are genetically modified ex vivo to express chimeric antigen receptors (CARs) to redirect their specificity to target tumor-associated antigens in vivo. We now have developed this molecular strategy to render cytotoxic T cells specific for fungi. We adapted the pattern-recognition receptor Dectin-1 to activate T cells via chimeric CD28 and CD3-? (designated "D-CAR") upon binding with carbohydrate in the cell wall of Aspergillus germlings. T cells genetically modified with the Sleeping Beauty system to express D-CAR stably were propagated selectively on artificial activating and propagating cells using an approach similar to that approved by the Food and Drug Administration for manufacturing CD19-specific CAR(+) T cells for clinical trials. The D-CAR(+) T cells exhibited specificity for ?-glucan which led to damage and inhibition of hyphal growth of Aspergillus in vitro and in vivo. Treatment of D-CAR(+) T cells with steroids did not compromise antifungal activity significantly. These data support the targeting of carbohydrate antigens by CAR(+) T cells and provide a clinically appealing strategy to enhance immunity for opportunistic fungal infections using T-cell gene therapy. PMID:25002471

Kumaresan, Pappanaicken R; Manuri, Pallavi R; Albert, Nathaniel D; Maiti, Sourindra; Singh, Harjeet; Mi, Tiejuan; Roszik, Jason; Rabinovich, Brian; Olivares, Simon; Krishnamurthy, Janani; Zhang, Ling; Najjar, Amer M; Huls, M Helen; Lee, Dean A; Champlin, Richard E; Kontoyiannis, Dimitrios P; Cooper, Laurence J N

2014-07-22

326

The opportunistic fungal pathogen Scedosporium prolificans: carbohydrate epitopes of its glycoproteins.  

PubMed

Isolated from the mycelium of Scedosporium prolificans were complex glycoproteins (RMP-Sp), with three structurally related components (HPSEC). RMP-Sp contained 35% protein and 62% carbohydrate with Rha, Ara, Man, Gal, Glc, and GlcNH(2) in a 18:1:24:8:6:5 molar ratio. Methylation analysis showed mainly nonreducing end- of Galp (13%), nonreducing end- (9%), 2-O- (13%), and 3-O-subst. Rhap (7%), nonreducing end- (11%), 2-O- (10%), 3-O- (14%), and 2,6-di-O-subst. Manp units (13%). Mild reductive beta-elimination of RMP-Sp gave alpha-l-Rhap-(1-->2)-alpha-l-Rhap-(1-->3)-alpha-l-Rhap-(1-->3)-alpha-d-Manp-(1-->2)-d-Man-ol, with Man-ol substituted at O-6 with beta-d-Galp units, a related pentasaccharide lacking beta-d-Galp units, and beta-d-Galp-(1-->6)-[alpha-d-Manp-(1-->2)]-d-Man-ol in a 16:3:1w/w ratio. Traces of Man-ol and Rha-ol were detected. ESI-MS showed HexHex-ol and Hex(3-6)Hex-ol components. Three rhamnosyl units were peeled off successively from the penta- and hexasaccharide by ESI-MS-MS. The carbohydrate epitopes of RMP-Sp differ from those of the glycoprotein of Pseudallescheria boydii, a related opportunistic pathogen. PMID:17996291

Barreto-Bergter, E; Sassaki, G L; Wagner, R; Souza, L M; Souza, M V A R; Pinto, M R; da Silva, M I D; Gorin, P A J

2008-03-01

327

Agent-Based Modeling Approach of Immune Defense Against Spores of Opportunistic Human Pathogenic Fungi  

PubMed Central

Opportunistic human pathogenic fungi like the ubiquitous fungus Aspergillus fumigatus are a major threat to immunocompromised patients. An impaired immune system renders the body vulnerable to invasive mycoses that often lead to the death of the patient. While the number of immunocompromised patients is rising with medical progress, the process, and dynamics of defense against invaded and ready to germinate fungal conidia are still insufficiently understood. Besides macrophages, neutrophil granulocytes form an important line of defense in that they clear conidia. Live imaging shows the interaction of those phagocytes and conidia as a dynamic process of touching, dragging, and phagocytosis. To unravel strategies of phagocytes on the hunt for conidia an agent-based modeling approach is used, implemented in NetLogo. Different modes of movement of phagocytes are tested regarding their clearing efficiency: random walk, short-term persistence in their recent direction, chemotaxis of chemokines excreted by conidia, and communication between phagocytes. While the short-term persistence hunting strategy turned out to be superior to the simple random walk, following a gradient of chemokines released by conidial agents is even better. The advantage of communication between neutrophilic agents showed a strong dependency on the spatial scale of the focused area and the distribution of the pathogens. PMID:22557995

Tokarski, Christian; Hummert, Sabine; Mech, Franziska; Figge, Marc Thilo; Germerodt, Sebastian; Schroeter, Anja; Schuster, Stefan

2012-01-01

328

Agent-based modeling approach of immune defense against spores of opportunistic human pathogenic fungi.  

PubMed

Opportunistic human pathogenic fungi like the ubiquitous fungus Aspergillus fumigatus are a major threat to immunocompromised patients. An impaired immune system renders the body vulnerable to invasive mycoses that often lead to the death of the patient. While the number of immunocompromised patients is rising with medical progress, the process, and dynamics of defense against invaded and ready to germinate fungal conidia are still insufficiently understood. Besides macrophages, neutrophil granulocytes form an important line of defense in that they clear conidia. Live imaging shows the interaction of those phagocytes and conidia as a dynamic process of touching, dragging, and phagocytosis. To unravel strategies of phagocytes on the hunt for conidia an agent-based modeling approach is used, implemented in NetLogo. Different modes of movement of phagocytes are tested regarding their clearing efficiency: random walk, short-term persistence in their recent direction, chemotaxis of chemokines excreted by conidia, and communication between phagocytes. While the short-term persistence hunting strategy turned out to be superior to the simple random walk, following a gradient of chemokines released by conidial agents is even better. The advantage of communication between neutrophilic agents showed a strong dependency on the spatial scale of the focused area and the distribution of the pathogens. PMID:22557995

Tokarski, Christian; Hummert, Sabine; Mech, Franziska; Figge, Marc Thilo; Germerodt, Sebastian; Schroeter, Anja; Schuster, Stefan

2012-01-01

329

Propionibacterium acnes: from commensal to opportunistic biofilm-associated implant pathogen.  

PubMed

Propionibacterium acnes is known primarily as a skin commensal. However, it can present as an opportunistic pathogen via bacterial seeding to cause invasive infections such as implant-associated infections. These infections have gained more attention due to improved diagnostic procedures, such as sonication of explanted foreign materials and prolonged cultivation time of up to 14 days for periprosthetic biopsy specimens, and improved molecular methods, such as broad-range 16S rRNA gene PCR. Implant-associated infections caused by P. acnes are most often described for shoulder prosthetic joint infections as well as cerebrovascular shunt infections, fibrosis of breast implants, and infections of cardiovascular devices. P. acnes causes disease through a number of virulence factors, such as biofilm formation. P. acnes is highly susceptible to a wide range of antibiotics, including beta-lactams, quinolones, clindamycin, and rifampin, although resistance to clindamycin is increasing. Treatment requires a combination of surgery and a prolonged antibiotic treatment regimen to successfully eliminate the remaining bacteria. Most authors suggest a course of 3 to 6 months of antibiotic treatment, including 2 to 6 weeks of intravenous treatment with a beta-lactam. While recently reported data showed a good efficacy of rifampin against P. acnes biofilms, prospective, randomized, controlled studies are needed to confirm evidence for combination treatment with rifampin, as has been performed for staphylococcal implant-associated infections. PMID:24982315

Achermann, Yvonne; Goldstein, Ellie J C; Coenye, Tom; Shirtliff, Mark E

2014-07-01

330

Functional Characterization of the RNA Chaperone Hfq in the Opportunistic Human Pathogen Stenotrophomonas maltophilia  

PubMed Central

Hfq is an RNA-binding protein known to regulate a variety of cellular processes by interacting with small RNAs (sRNAs) and mRNAs in prokaryotes. Stenotrophomonas maltophilia is an important opportunistic pathogen affecting primarily hospitalized and immunocompromised hosts. We constructed an hfq deletion mutant (?hfq) of S. maltophilia and compared the behaviors of wild-type and ?hfq S. maltophilia cells in a variety of assays. This revealed that S. maltophilia Hfq plays a role in biofilm formation and cell motility, as well as susceptibility to antimicrobial agents. Moreover, Hfq is crucial for adhesion to bronchial epithelial cells and is required for the replication of S. maltophilia in macrophages. Differential RNA sequencing analysis (dRNA-seq) of RNA isolated from S. maltophilia wild-type and ?hfq strains showed that Hfq regulates the expression of genes encoding flagellar and fimbrial components, transmembrane proteins, and enzymes involved in different metabolic pathways. Moreover, we analyzed the expression of several sRNAs identified by dRNA-seq in wild-type and ?hfq S. maltophilia cells grown in different conditions on Northern blots. The accumulation of two sRNAs was strongly reduced in the absence of Hfq. Furthermore, based on our dRNA-seq analysis we provide a genome-wide map of transcriptional start sites in S. maltophilia. PMID:22923593

Roscetto, Emanuela; Angrisano, Tiziana; Costa, Valerio; Casalino, Mariassunta; Förstner, Konrad U.; Sharma, Cynthia M.; Di Nocera, Pier Paolo

2012-01-01

331

Genetic Identification of the Main Opportunistic Mucorales by PCR-Restriction Fragment Length Polymorphism  

PubMed Central

Mucormycosis is a rare and opportunistic infection caused by fungi belonging to the order Mucorales. Recent reports have demonstrated an increasing incidence of mucormycosis, which is frequently lethal, especially in patients suffering from severe underlying conditions such as immunodeficiency. In addition, even though conventional mycology and histopathology assays allow for the identification of Mucorales, they often fail in offering a species-specific diagnosis. Due to the lack of other laboratory tests, a precise identification of these molds is thus notoriously difficult. In this study we aimed to develop a molecular biology tool to identify the main Mucorales involved in human pathology. A PCR strategy selectively amplifies genomic DNA from molds belonging to the genera Absidia, Mucor, Rhizopus, and Rhizomucor, excluding human DNA and DNA from other filamentous fungi and yeasts. A subsequent digestion step identified the Mucorales at genus and species level. This technique was validated using both fungal cultures and retrospective analyses of clinical samples. By enabling a rapid and precise identification of Mucorales strains in infected patients, this PCR-restriction fragment length polymorphism-based method should help clinicians to decide on the appropriate treatment, consequently decreasing the mortality of mucormycosis. PMID:16517858

Machouart, M.; Larché, J.; Burton, K.; Collomb, J.; Maurer, P.; Cintrat, A.; Biava, M. F.; Greciano, S.; Kuijpers, A. F. A.; Contet-Audonneau, N.; de Hoog, G. S.; Gérard, A.; Fortier, B.

2006-01-01

332

Kaposi's sarcoma: an opportunistic infection by human herpesvirus-8 in ulcerative colitis.  

PubMed

Kaposi's sarcoma is a vascular tumor caused by human herpesvirus-8 infection. Iatrogenic Kaposi's sarcoma often occurs in patients receiving immunosuppressive therapy. To date, a few cases of colonic Kaposi's sarcoma have been reported in ulcerative colitis patients treated with immunomodulators. We describe a 65-year-old male diagnosed with left-sided ulcerative colitis who was treated with methotrexate and low-dose steroids for greater than 6 years. He presented with several papular, violet lesions on both legs. Colonoscopy revealed the presence of multiple reddish, elevated lesions in the sigmoid colon and rectum. Histological evaluation of skin and colonic biopsies showed findings suggestive of Kaposi's sarcoma; immunohistochemistry for human herpesvirus-8 was positive in the colonic lesions. To avoid the need for further immunosuppressive treatment, the patient underwent a colectomy. Following immunomodulator discontinuation, the patient experienced spontaneous regression of his skin lesions. With the present case, we wish to stress the important interaction of immunosuppressive therapy (mainly corticosteroids) used in ulcerative colitis patients in relation to the development of colonic Kaposi's sarcoma. Human herpesvirus-8 infection should be recognized as a possible opportunistic infection in patients with inflammatory bowel disease. PMID:21122564

Rodríguez-Peláez, María; Fernández-García, María Soledad; Gutiérrez-Corral, Natalia; de Francisco, Ruth; Riestra, Sabino; García-Pravia, Carmen; Rodríguez, José Ignacio; Rodrigo, Luis

2010-11-01

333

Seasonal Changes in Brain GnRH Immunoreactivity and Song-Control Nuclei Volumes in an Opportunistically Breeding Songbird  

Microsoft Academic Search

White-winged crossbills (Loxia leucoptera) are opportunistic breeders that can nest at almost any time of year if there is sufficient food. Other cardueline finches that have been shown to breed on a strictly seasonal schedule become absolutely refractory to the stimulatory effects of long-day photoperiod, dramatically down-regulate hypothalamic gonadotropin-releasing hormone (GnRH), and reduce the volume of several song-control nuclei in

Scott A. MacDougall-Shackleton; Pierre J. Deviche; Renee D. Crain; Gregory F. Ball; Thomas P. Hahn

2001-01-01

334

Standard Integration of Sensing and Opportunistic Diffusion for Urban Monitoring in Vehicular Sensor Networks: the MobEyes Architecture  

Microsoft Academic Search

The emerging industrial relevance of vehicular sensor networks pushes towards their adoption for large-scale applications, from traffic routing and relief to environmental monitoring and distributed surveillance. With homeland security issues in mind, we have developed MobEyes, a fully distributed opportunistic harvesting system for urban monitoring. In MobEyes, regular vehicles equipped with sensors collect and locally store monitoring data while moving

Paolo Bellavista; Eugenio Magistretti; Uichin Lee; Mario Gerla

2007-01-01

335

Democratization’s Risk Premium: Partisan and Opportunistic Political Business Cycle Effects on Sovereign Ratings in Developing Countries  

Microsoft Academic Search

We use partisan and opportunistic political business cycle (“PBC”) considerations to develop a framework for explaining election-period decisions by credit rating agencies (“agencies”) publishing developing country sovereign risk-ratings (“ratings”). We test six hypotheses derived from the framework with 482 agency ratings for 19 countries holding 39 presidential elections from 1987-2000. We find that ratings are linked to the partisan orientation

Steven Block; Burkhard N. Schrage; Paul M. Vaaler

2003-01-01

336

Constraint satisfaction using a hybrid evolutionary hill-climbing algorithm that performs opportunistic arc and path revision  

SciTech Connect

This paper introduces a hybrid evolutionary hill-climbing algorithm that quickly solves (Constraint Satisfaction Problems (CSPs)). This hybrid uses opportunistic arc and path revision in an interleaved fashion to reduce the size of the search space and to realize when to quit if a CSP is based on an inconsistent constraint network. This hybrid outperforms a well known hill-climbing algorithm, the Iterative Descent Method, on a test suite of 750 randomly generated CSPs.

Bowen, J. [National Univ. of Ireland, Cork (Ireland); Dozier, G. [North Carolina A& T State Univ., Greensboro, NC (United States)

1996-12-31

337

Common Career Technical Core: Common Standards, Common Vision for CTE  

ERIC Educational Resources Information Center

This article provides an overview of the National Association of State Directors of Career Technical Education Consortium's (NASDCTEc) Common Career Technical Core (CCTC), a state-led initiative that was created to ensure that career and technical education (CTE) programs are consistent and high quality across the United States. Forty-two states,…

Green, Kimberly

2012-01-01

338

Toward perpetual wireless networks: Opportunistic large arrays with transmission thresholds and energy harvesting  

NASA Astrophysics Data System (ADS)

Solving the key issue of sustainability of battery-powered sensors continues to attract significant research attention. The prevailing theme of this research is to address this concern using energy-efficient protocols based on a form of simple cooperative transmission (CT) called the opportunistic large arrays (OLAs), and intelligent exploitation of energy harvesting and hybrid energy storage systems (HESSs). The two key contributions of this research, namely, OLA with transmission threshold (OLA-T) and alternating OLA-T (A-OLA-T), offer an signal-to-noise ratio (SNR) advantage (i.e., benefits of diversity and array (power) gains) in a multi-path fading environment, thereby reducing transmit powers or extending range. Because these protocols do not address nodes individually, the network overhead remains constant for high density networks or nodes with mobility. During broadcasting across energy-constrained networks, while OLA-T saves energy by limiting node participation within a single broadcast, A-OLA-T optimizes over multiple broadcasts and drains the nodes in an equitable fashion. A major bottleneck for network sustainability is the ability of a rechargeable battery (RB) to store energy, which is limited by the number of charge-discharge cycles. Energy harvesting using a HESS that comprises a RB and a supercapacitor (SC) will minimize the RB usage, thereby preserving the charge-discharge cycles. Studying the HESS is important, rather than the SC-alone because while an SC with harvested energy may be sufficient for routine monitoring, if there is an alert, the RB could be used as necessary to support the heavier reporting requirements. Therefore, another key contribution of this research is the design and analysis of a novel routing metric called communications using HESS (CHESS), which extends the RB-life by relaying exclusively with SC energy.

Kailas, Aravind

339

Symptoms of Fern Distortion Syndrome Resulting from Inoculation with Opportunistic Endophytic Fluorescent Pseudomonas spp.  

PubMed Central

Background Fern Distortion Syndrome (FDS) is a serious disease of Leatherleaf fern (Rumohra adiantiformis). The main symptom of FDS is distortion of fronds, making them unmarketable. Additional symptoms include stunting, irregular sporulation, decreased rhizome diameter, and internal discoloration of rhizomes. We previously reported an association of symptoms with increased endophytic rhizome populations of fluorescent pseudomonads (FPs). The aim of the current study was to determine if FPs from ferns in Costa Rica with typical FDS symptoms would recreate symptoms of FDS. Methodology and Findings Greenhouse tests were conducted over a 29-month period. Micro-propagated ferns derived from tissue culture were first grown one year to produce rhizomes. Then, using an 8×9 randomized complete block experimental design, 8 replicate rhizomes were inoculated by dipping into 9 different treatments before planting. Treatments included water without bacteria (control), and four different groups of FPs, each at a two concentrations. The four groups of FPs included one group from healthy ferns without symptoms (another control treatment), two groups isolated from inside rhizomes of symptomatic ferns, and one group isolated from inside roots of symptomatic ferns. Symptoms were assessed 12 and 17 months later, and populations of FPs inside newly formed rhizomes were determined after 17 months. Results showed that inoculation with mixtures of FPs from ferns with FDS symptoms, but not from healthy ferns, recreated the primary symptom of frond deformities and also the secondary symptoms of irregular sporulation, decreased rhizome diameter, and internal discoloration of rhizomes. Conclusions These results suggest a model of causation of FDS in which symptoms result from latent infections by multiple species of opportunistic endophytic bacteria containing virulence genes that are expressed when populations inside the plant reach a minimum level. PMID:23516499

Kloepper, Joseph W.; McInroy, John A.; Liu, Ke; Hu, Chia-Hui

2013-01-01

340

Opportunistic activation of TRP receptors by endogenous lipids: Exploiting lipidomics to understand TRP receptor cellular communication  

PubMed Central

Transient receptor potential channels (TRPs) form a large family of ubiquitous non-selective cation channels that function as cellular sensors and in many cases regulate intracellular calcium. Identification of the endogenous ligands that activate these TRP receptors is still under intense investigation with the majority of these channels still remaining “orphans”. That these channels respond to a variety of external stimuli (e.g. plant-derived lipids, changes in temperature, and changes in pH) provides a framework for their abilities as cellular sensors, however, the mechanism of direct activation is still under much debate and research. In the cases where endogenous ligands (predominately lipids) have shown direct activation of a channel, multiple ligands have been shown to activate the same channel suggesting that these receptors are “promiscuous” in nature. Lipidomics of a growing class of endogenous lipids, N-acyl amides, the most famous of which is N-arachidonoyl ethanolamine (the endogenous cannabinoid, Anandamide) is providing a novel set of ligands that have been shown to activate some members of the TRP family and have the potential to deorphanize many more. Here it is argued that activation of TRPV receptors, a subset of the larger family of TRPs, by multiple endogenous lipids that are structurally analogous is a model system to drive our understanding that many TRP receptors are not promiscuous, but are more characteristically “opportunistic” in nature; exploiting the structural similarity and biosynthesis of a narrow range of analogous endogenous lipids. In addition, this manuscript will compare the activation properties of TRPC5 to the activity profile of an “orphan” lipid, N-palmitoyl glycine; further demonstrating that lipidomics aimed at expanding our knowledge of the family of N-acyl amides has the potential to provide novel avenues of research for TRP receptors. PMID:23178153

Bradshaw, Heather B.; Raboune, Siham; Hollis, Jennifer L.

2012-01-01

341

Common Tests for Arrhythmia  

MedlinePLUS

Common Tests for Arrhythmia Updated:Dec 7,2012 Several tests can help your doctor diagnose an arrhythmia ( ... a lot about the heart and its rhythm. Common Tests for Arrhythmia Electrocardiography (ECG or EKG) An ...

342

How Common Is PTSD?  

MedlinePLUS

... Guidelines Hospital Quality Data Medical Inspector Patient Safety Organizations Administrative Clinical Quick Links Enter ZIP code here Enter ZIP code here How Common is PTSD? How Common is PTSD? Posttraumatic stress disorder (PTSD) can occur after you have been ...

343

Common ratio using delay  

Microsoft Academic Search

We present an experiment in which we add a common delay in a choice between two risky prospects. The results show that delay\\u000a produces the same change in preferences as in the well-documented common ratio effect in risky lotteries. The added common\\u000a delay acts as if the probabilities were divided by some common ratio. Moreover, we show that there is

Manel Baucells; Franz H. Heukamp

2010-01-01

344

HIV-related neurocognitive impairment – A review  

Microsoft Academic Search

Neurocognitive impairments following central nervous system opportunistic infections and HIV-associated dementia (HAD) were common clinical features of HIV infection prior to anti-retroviral therapy. As HIV infection has evolved from an invariably fatal disease with a poor prognosis to a condition requiring long-term management, HIV-related neurocognitive disorders have been the subject of increasing research. This review will examine the recent changes

Simon Rackstraw

2011-01-01

345

PAS Domains COMMON STRUCTURE AND COMMON FLEXIBILITY*  

E-print Network

at the amino acid sequence level. The photoac- tive yellow protein, a bacterial light sensor, has been proposed of Dundee, Dundee DD1 5EH, Scotland PAS (PER-ARNT-SIM) domains are a family of sensor protein domains in their conformational flexibilities. The observed motions point to a possible common mecha- nism for communicating

van Aalten, Daan

346

Reproductive endocrinology of a free-living, opportunistically breeding passerine (white-winged crossbill, Loxia leucoptera).  

PubMed

The aim of the study was to investigate, in a free-living opportunistic breeder, the White-winged Crossbill (Loxia leucoptera), the degree to which annual changes in photoperiod and differences in the timing of breeding in different years correlate with the secretion of reproductive hormones. Seasonal changes in concentrations of luteinizing hormone (LH) and prolactin were compared in White-winged Crossbills in interior Alaska (64 degrees 50'N, 147 degrees 50'W) in plasma samples taken in May-December 1994 and July 1998-August 1999. The birds were in breeding condition in May-July 1994 and in February-April 1999. Additional observations were made on plasma testosterone (T) in males in 1998/1999. In 1998, in adult males, plasma LH and T were low in September-October (LH: <0.4 ng/ml; T: undetectable) and increased significantly in November (LH: 3.65 +/- 2.20 ng/ml) and December (T: 0.69 +/- 0.88 ng/ml). Thereafter, plasma T increased to 2.35 +/- 2.03 ng/ml in March/April and returned to basal levels by June/July. In 1998/1999, in females, plasma LH did not change seasonally. In males in 1994, plasma LH was higher in June (2.15 +/- 1.22 ng/ml) and July (2.86 +/- 0.69 ng/ml) than in the same period in 1999 (June: 1.20 +/- 1.82 ng/ml; July: 1.37 +/- 1.03 ng/ml), which is consistent with the later breeding season in 1994. In 1994 and 1998/1999 in both sexes, concentrations of plasma prolactin were elevated when day lengths exceeded about 12 h, being high during late spring to early fall (males: 40-130 ng/ml; females: 40-140 ng/ml) and low during winter (<15 ng/ml in both sexes). In 1994 and 1998, molt occurred during the fall, at a time when breeding did not occur, although conifer seeds were sufficiently abundant to support a large bird population. These data are consistent with the view that White-winged Crossbills have the potential to breed at all times of the year except when molting in the fall. It is likely that a photoinduced increase in prolactin secretion is a factor that induces molt. Crossbills may not breed when they are molting because of increased metabolic demands for feather formation and for the maintenance of basal metabolism at a time of year when ambient temperatures fall well below 0 degrees. Alternatively or in addition, the birds may become reproductively photorefractory. PMID:11589628

Deviche, P; Sharp, P J

2001-09-01

347

Scabies Mites Alter the Skin Microbiome and Promote Growth of Opportunistic Pathogens in a Porcine Model  

PubMed Central

Background The resident skin microbiota plays an important role in restricting pathogenic bacteria, thereby protecting the host. Scabies mites (Sarcoptes scabiei) are thought to promote bacterial infections by breaching the skin barrier and excreting molecules that inhibit host innate immune responses. Epidemiological studies in humans confirm increased incidence of impetigo, generally caused by Staphylococcus aureus and Streptococcus pyogenes, secondary to the epidermal infestation with the parasitic mite. It is therefore possible that mite infestation could alter the healthy skin microbiota making way for the opportunistic pathogens. A longitudinal study to test this hypothesis in humans is near impossible due to ethical reasons. In a porcine model we generated scabies infestations closely resembling the disease manifestation in humans and investigated the scabies associated changes in the skin microbiota over the course of a mite infestation. Methodology/Principal Findings In a 21 week trial, skin scrapings were collected from pigs infected with S. scabies var. suis and scabies-free control animals. A total of 96 skin scrapings were collected before, during infection and after acaricide treatment, and analyzed by bacterial 16S rDNA tag-encoded FLX-titanium amplicon pyrosequencing. We found significant changes in the epidermal microbiota, in particular a dramatic increase in Staphylococcus correlating with the onset of mite infestation in animals challenged with scabies mites. This increase persisted beyond treatment from mite infection and healing of skin. Furthermore, the staphylococci population shifted from the commensal S. hominis on the healthy skin prior to scabies mite challenge to S. chromogenes, which is increasingly recognized as being pathogenic, coinciding with scabies infection in pigs. In contrast, all animals in the scabies-free cohort remained relatively free of Staphylococcus throughout the trial. Conclusions/Significance This is the first experimental in vivo evidence supporting previous assumptions that establishment of pathogens follow scabies infection. Our findings provide an explanation for a biologically important aspect of the disease pathogenesis. The methods developed from this pig trial will serve as a guide to analyze human clinical samples. Studies building on this will offer implications for development of novel intervention strategies against the mites and the secondary infections. PMID:24875186

Swe, Pearl M.; Zakrzewski, Martha; Kelly, Andrew; Krause, Lutz; Fischer, Katja

2014-01-01

348

In Vitro Activity of the New Triazole Voriconazole (UK109,496) against Opportunistic Filamentous and Dimorphic Fungi and Common and Emerging Yeast Pathogens  

Microsoft Academic Search

The in vitro antifungal activity of a new triazole derivative, voriconazole, was compared with those of itraconazole and amphotericin B against 67 isolates of Aspergillus flavus, Aspergillus fumigatus, Bipolaris spp., Fusarium oxysporum, Fusarium solani, Pseudallescheria boydii, Rhizopus arrhizus, Blastomyces dermatitidis, His- toplasma capsulatum, and Sporothrix schenckii. The in vitro activities of voriconazole were also compared with those of amphotericin B,

ANA ESPINEL-INGROFF

1998-01-01

349

Symbiotic mutualism with a community of opportunistic ants: protection, competition, and ant occupancy of the myrmecophyte Barteria nigritana (Passifloraceae)  

NASA Astrophysics Data System (ADS)

Barteria nigritana is a myrmecophyte tree of Lower Guinea coastal vegetation. Unlike the more specialised B. fistulosa, which harbours a single host-specific mutualistic ant, B. nigritana is associated with several opportunistic ants. Such symbiotic, yet opportunistic, ant-plant associations have been little studied. On 113 clumps of B. nigritana, we censused ant associates and herbivores and compared herbivory on plants occupied by different ants. In addition to these correlative data, protection conferred by different ant species was compared by herbivore-placement experiments. Identity of ant associate changed predictably over plant ontogeny. Pheidole megacephala was restricted to very small plants; saplings were occupied by either Oecophylla longinoda or Crematogaster sp., and the latter species was the sole occupant of larger trees. Damage by caterpillars of the nymphalid butterfly Acraea zetes accounted for much of the herbivory to leaves. Ant species differed in the protection provided to hosts. While P. megacephala provided no significant protection, plants occupied by O. longinoda and Crematogaster sp. suffered less damage than did unoccupied plants or those occupied by P. megacephala. Furthermore, O. longinoda provided more effective protection than did Crematogaster sp. Herbivore-placement experiments confirmed these results. Workers of O. longinoda killed or removed all larval instars of A. zetes. Crematogaster preyed on only the two first larval instars, and P. megacephala preyed mainly on eggs, only rarely attacking the two first larval instars. Opportunistic ants provided significant protection to this relatively unspecialised myrmecophyte. The usual associate of mature trees was not the species that provided most protection.

Djiéto-Lordon, Champlain; Dejean, Alain; Gibernau, Marc; Hossaert-McKey, Martine; McKey, Doyle

2004-10-01

350

Members of native coral microbiota inhibit glycosidases and thwart colonization of coral mucus by an opportunistic pathogen  

PubMed Central

The outcome of the interactions between native commensal microorganisms and opportunistic pathogens is crucial to the health of the coral holobiont. During the establishment within the coral surface mucus layer, opportunistic pathogens, including a white pox pathogen Serratia marcescens PDL100, compete with native bacteria for available nutrients. Both commensals and pathogens employ glycosidases and N-acetyl-glucosaminidase to utilize components of coral mucus. This study tested the hypothesis that specific glycosidases were critical for the growth of S. marcescens on mucus and that their inhibition by native coral microbiota reduces fitness of the pathogen. Consistent with this hypothesis, a S. marcescens transposon mutant with reduced glycosidase and N-acetyl-glucosaminidase activities was unable to compete with the wild type on the mucus of the host coral Acropora palmata, although it was at least as competitive as the wild type on a minimal medium with glycerol and casamino acids. Virulence of the mutant was modestly reduced in the Aiptasia model. A survey revealed that ?8% of culturable coral commensal bacteria have the ability to inhibit glycosidases in the pathogen. A small molecular weight, ethanol-soluble substance(s) produced by the coral commensal Exiguobacterium sp. was capable of the inhibition of the induction of catabolic enzymes in S. marcescens. This inhibition was in part responsible for the 10–100-fold reduction in the ability of the pathogen to grow on coral mucus. These results provide insight into potential mechanisms of commensal interference with early colonization and infection behaviors in opportunistic pathogens and highlight an important function for the native microbiota in coral health. PMID:23254513

Krediet, Cory J; Ritchie, Kim B; Alagely, Ali; Teplitski, Max

2013-01-01

351

Common Bayesian models for common cognitive issues.  

PubMed

How can an incomplete and uncertain model of the environment be used to perceive, infer, decide and act efficiently? This is the challenge that both living and artificial cognitive systems have to face. Symbolic logic is, by its nature, unable to deal with this question. The subjectivist approach to probability is an extension to logic that is designed specifically to face this challenge. In this paper, we review a number of frequently encountered cognitive issues and cast them into a common Bayesian formalism. The concepts we review are ambiguities, fusion, multimodality, conflicts, modularity, hierarchies and loops. First, each of these concepts is introduced briefly using some examples from the neuroscience, psychophysics or robotics literature. Then, the concept is formalized using a template Bayesian model. The assumptions and common features of these models, as well as their major differences, are outlined and discussed. PMID:20658175

Colas, Francis; Diard, Julien; Bessière, Pierre

2010-09-01

352

Microbial diversities (16S and 18S rDNA gene pyrosequencing) and environmental pathogens within drinking water biofilms grown on the common premise plumbing materials unplasticized polyvinylchloride and copper  

EPA Science Inventory

Drinking water (DW) biofilm communities influence the survival of opportunistic pathogens, e.g. Legionella pneumophila, via parasitization of free-living amoebae such as Acanthamoebae. Yet knowledge about the microbial composition of DW biofilms developed on common in-premise pl...

353

USE OF THE GEOGRAPHIC INFORMATION SYSTEM TO INVESTIGATE MERCURY LEVELS IN CORRELATION WITH POSTMORTEM FINDINGS OF ASPERGILLUS INDUCED LESIONS IN THE COMMON LOON (GAVIA IMMER) IN THE NORTHEASTERN USA  

EPA Science Inventory

This study employed the Geographic Information System (GIS) to correlate total mercury levels in liver tissue with post-mortem findings of aspergillosis in common loons (Gavia immer) in the northeast United States of America (USA). Aspergillosis is an opportunistic fungal infecti...

354

NSDL Math Common Core  

NSDL National Science Digital Library

The NSDL Math Common Core collection provides quick and easy access to high-quality math resources that have been related to one or more standard statements within the Math Common Core. These resources are selected from the larger NSDL collection and other trusted providers, and organized by grade level and domain area.

2010-08-10

355

Communication and Common Interest  

PubMed Central

Explaining the maintenance of communicative behavior in the face of incentives to deceive, conceal information, or exaggerate is an important problem in behavioral biology. When the interests of agents diverge, some form of signal cost is often seen as essential to maintaining honesty. Here, novel computational methods are used to investigate the role of common interest between the sender and receiver of messages in maintaining cost-free informative signaling in a signaling game. Two measures of common interest are defined. These quantify the divergence between sender and receiver in their preference orderings over acts the receiver might perform in each state of the world. Sampling from a large space of signaling games finds that informative signaling is possible at equilibrium with zero common interest in both senses. Games of this kind are rare, however, and the proportion of games that include at least one equilibrium in which informative signals are used increases monotonically with common interest. Common interest as a predictor of informative signaling also interacts with the extent to which agents' preferences vary with the state of the world. Our findings provide a quantitative description of the relation between common interest and informative signaling, employing exact measures of common interest, information use, and contingency of payoff under environmental variation that may be applied to a wide range of models and empirical systems. PMID:24244116

Godfrey-Smith, Peter; Martinez, Manolo

2013-01-01

356

Common clay and shale  

USGS Publications Warehouse

Part of the 2003 industrial minerals review. The legislation, production, and consumption of common clay and shale are discussed. The average prices of the material and outlook for the market are provided.

Virta, R.L.

2004-01-01

357

Ten Common NWP Misconceptions  

NSDL National Science Digital Library

This module introduces forecasters to ten of the most commonly encountered or significant misconceptions about NWP models. This list of ten misconceptions includes issues surrounding data assimilation, model resolution, physical parameterizations, and post-processing of model forecast output.

Comet

2002-05-02

358

Deriving Common Model Characteristics  

NSDL National Science Digital Library

In this activity, students confront several different models - from the DNA helix Watson and Crick constructed in their laboratory to a map of McDonalds density in the US - and work in small groups to derive their commonalities.

Momsen, Jennifer; Long, Tammy M.; Speth, Elena B.

359

Common Variable Immunodeficiency (CVID)  

MedlinePLUS

... on. Read more information on enabling JavaScript. Primary Immune Deficiency Diseases Skip Content Marketing Share this: Main Content Area Common Variable Immunodeficiency (CVID) Crystal structure of the antibody immunoglobulin ...

360

Common Foot Problems  

MedlinePLUS

... infections include warts; the common disease athlete's foot (tinea pedis), which is caused by a foot fungus ... see additional images and learn more. Athlete's Foot (Tinea Pedis) Tinea pedis, also known as ringworm of ...

361

Five Common Glaucoma Tests  

MedlinePLUS

Five Common Glaucoma Tests en Español email Send this article to a friend by filling out the fields below: Your name: ... year or two after age 35. A Comprehensive Glaucoma Exam To be safe and accurate, five factors ...

362

Biomarkers and HIV-Associated Cardiovascular Disease  

PubMed Central

Purpose of Review Our goal is to summarize recent literature on biomarkers of cardiovascular disease (CVD) in the setting of HIV infection with an emphasis on those associated with clinical events. Recent Findings Epidemiological data have demonstrated that HIV-infection is associated with increases in well-established markers of inflammation and thrombosis, and levels of hsCRP, IL-6, D-dimer and fibrinogen predict CVD and mortality risk in HIV cohorts. Levels of IL-6, D-dimer and endothelial adhesion molecules increase when antiretroviral therapy is interrupted, suggesting HIV replication may be driving CVD risk in this context. However, data on changes in many CVD biomarkers after starting ART are inconsistent or lacking. Finally, assessment of high-density lipoprotein particle concentration may provide important information specific to HIV-related CVD risk beyond that apparent from traditional measures of serum cholesterol. Summary Biomarkers of inflammation and thrombosis have the potential to improve CVD risk stratification beyond traditional and HIV-specific factors, and may prove useful for evaluating CVD prevention strategies for individuals with HIV infection. PMID:20978394

Baker, Jason V.; Duprez, Daniel

2014-01-01

363

Pelvocalyceal thickening in HIV-associated nephropathy  

Microsoft Academic Search

Background  Previously reported causes of renal pelvocalyceal thickening (PCT) include infection, acute tubular necrosis and obstruction. This study was performed to evaluate the significance of PCT noted sonographically in patients with hyperechoic native kidneys.Methods  We evaluated sonograms of 178 consecutive patients with hyperechoic native (excluding small and hydronephrotic) kidneys for the presence of PCT, and reviewed medical charts of patients with this

R. H. Wachsberg; A. T. Obolevich; N. Lasker

1995-01-01

364

Approximate common knowledge revisited  

Microsoft Academic Search

.   Suppose we replace “knowledge” by “belief with probability p” in standard definitions of common knowledge. Very different notions arise depending on the exact definition of common knowledge\\u000a used in the substitution. This paper demonstrates those differences and identifies which notion is relevant in each of three\\u000a contexts: equilibrium analysis in incomplete information games, best response dynamics in incomplete information

Stephen Morris

1999-01-01

365

Common clay and shale  

USGS Publications Warehouse

At present, 150 companies produce common clay and shale in 41 US states. According to the United States Geological Survey (USGS), domestic production in 2005 reached 24.8 Mt valued at $176 million. In decreasing order by tonnage, the leading producer states include North Carolina, Texas, Alabama, Georgia and Ohio. For the whole year, residential and commercial building construction remained the major market for common clay and shale products such as brick, drain tile, lightweight aggregate, quarry tile and structural tile.

Virta, R.L.

2006-01-01

366

Common clay and shale  

USGS Publications Warehouse

The article discusses the latest developments in the global common clay and shale industry, particularly in the U.S. It claims that common clay and shale is mainly used in the manufacture of heavy clay products like brick, flue tile and sewer pipe. The main producing states in the U.S. include North Carolina, New York and Oklahoma. Among the firms that manufacture clay and shale-based products are Mid America Brick & Structural Clay Products LLC and Boral USA.

Virta, R.L.

2011-01-01

367

Common skin conditions.  

PubMed Central

Four common conditions: acne, psoriasis, eczema and urticaria are considered. Guidance is given on appropriate topical and systematic treatment for the different types and degrees of these conditions, with notes on management in general and criteria for referral to hospital outpatient departments. Where there are different types of the condition, with varying aetiology, for example in urticaria and eczema, management of the common types is outlined. PMID:1345156

Ridley, M.; Safranek, M.

1992-01-01

368

Common variable immunodeficiency  

Microsoft Academic Search

Common variable immunodeficiency (CVID) is a common primary immnodeficiency disease, the hallmark of which is hypogammaglobulinemia.\\u000a Due to the lack of antibodies, patients usually have recurrent bacterial infections, but there are a number of other puzzling\\u000a manifestations, including inflammatory conditions, autoimmune disease, and the development of lymphomas. Most patients are\\u000a diagnosed as adults, and delay in the recognition of the

Charlotte Cunningham-Rundles

2001-01-01

369

Multiple frequency bioimpedance is an adequate tool to assess total and regional fat mass in HIV-positive patients but not to diagnose HIV-associated lipoatrophy: a pilot study  

PubMed Central

Introduction HIV-associated lipodystrophy syndrome causes systemic metabolic alterations and psychological distress that worsen the quality of life of these patients. An early detection should be considered to efficiently treat it. Objective criteria or reference indices are needed for an early diagnosis. Bioelectrical Impedance Analysis (BIA) is an operator-independent, repeatable and non-invasive method of body composition evaluation that is less expensive than dual-energy X-ray absorptiometry (DXA) and/or CT scans. The aims of this pilot study were to validate the data obtained by BIA to measure fat mass in HIV-positive patients with/without lipoatrophy and to determine if BIA correctly diagnoses lipoatrophy in HIV-positive patients. Methods Thirty-nine participants were included in this preliminary study. Fourteen were HIV-negative (eight men) whereas 25 were HIV-positive patients (17 men). Eleven of the HIV-positive patients were classified as lipoatrophic according to subjective evaluation by the physicians. Total and regional body composition was measured in basal conditions by DXA and by BIA. To obtain abdominal CT scan fat values, transverse slices with 6-mm thickness were acquired at the L4-L5 intervertebral space. Results BIA measurements of total and regional body fat were significantly correlated with those obtained by DXA (p < 0.05 to <0.01) in HIV-positive patients. However, agreement between methods was poor as not very high ICC (intraclass correlation coefficient) values were observed. BIA and DXA showed higher ICC values in lipoatrophic patients. The visceral index obtained by BIA was correlated with total and visceral fat in L4 measured by CT scan (r = 0.607 and r = 0.617, respectively, p < 0.01) in HIV-positive patients. The Fat Mass Ratio (FMR) calculated by BIA did not correlate or agree with DXA values. Conclusions Multi-frequency BIA could be an effective method to evaluate the evolution of total and regional fat composition in HIV-positive patients with/without lipoatrophy. The correlations between BIA and DXA improved in lipoatrophic patients and in men, suggesting that its efficacy depends on fat mass, gender and probably other factors. The visceral index obtained by BIA seems to be a reliable indicator of abdominal obesity. However, BIA did not fulfil the need for easy quantitative diagnostic tools for lipoatrophy, and it did not provide sufficient diagnostic cut-off values for this syndrome. PMID:24378223

Perez-Matute, Patricia; Perez-Martinez, Laura; Blanco, Jose R; Ibarra, Valvanera; Metola, Luis; Sanz, Mercedes; Hernando, Luis; Martinez, Sagrario; Ramirez, Arsenio; Ramalle-Gomara, Enrique; Oteo, Jose A

2013-01-01

370

Cellular Immune Responses in HIV-Negative Immunodeficiency with Anti-Interferon-? Antibodies and Opportunistic Intracellular Microorganisms  

PubMed Central

Background Cell-mediated immunity plays a crucial role in resistance to intracellular infection. We previously reported antibodies against interferon-gamma (IFN-?) in HIV? negative (HIV?) patients with acquired immunodeficiency presenting with repeated episodes of disseminated infection caused by uncommon opportunistic intracellular fungal, bacterial, and viral pathogens. This follow-up study aimed to investigate cellular immune responses in these unusual patients. Methods Twenty HIV? patients presenting with ?2 episodes of culture- or histopathologic-proven opportunistic infections were enrolled along with age- and sex-matched controls comprised of 20 HIV+ patients plus 20 healthy adults. Monocyte phenotyping and intracellular cytokine production were determined by staining with specific antibodies followed by flow cytometry. Anti-interferon-? antibodies were measured by enzyme-linked immunosorbent assay, and inducible nitric oxide synthase by reverse-transcription polymerase chain reaction. Results There were no differences among cases, HIV+, and healthy controls in the percentage of monocytes, or CD68 and HLA-DR expression on their surfaces. FcR1 (CD119) expression on monocytes was significantly higher in cases than in HIV+ (p<0.05) and healthy controls (p<0.01), suggesting the presence of activated monocytes in the circulation. Interleukin (IL)-2 and tumor necrosis factor (TNF)-? production in CD4 cells were significantly lower in cases than in healthy controls (p<0.01 and p<0.001, respectively). CD8 production of TNF-? among cases was significantly lower than that of healthy controls (p<0.05). Conclusion Immunodeficiency in HIV? individuals with repeated infections with intracellular pathogens may be associated with one or more of the abnormal immune responses reflected by the reduced production of both IL-2 by CD4 T cells and TNF-? by CD4 T cells and CD8 T cells, as well as presence of anti-IFN-? antibody, as previously reported. PMID:25329064

Wipasa, Jiraprapa; Wongkulab, Panuwat; Chawansuntati, Kriangkrai; Chaiwarit, Romanee; Supparatpinyo, Khuanchai

2014-01-01

371

Dual roles of an algal farming damselfish as a cultivator and opportunistic browser of an invasive seaweed.  

PubMed

Herbivory is a fundamental process determining reef resilience, and while algal farming damselfishes can help shape benthic assemblages, an understanding of their contribution to areas outside of defended territories is relatively unexplored. Here, we demonstrate how the farming damselfish Stegastes marginatus plays a dual role in benthic structuring by 1) contributing to persistence of the invasive macroalga Acanthophora spicifera within a Hawaiian marine protected area, where the macroalga occurred exclusively inside Stegastes territories, and 2) behaving as an opportunistic browser of the exotic alga outside their territorial borders. Greater than 50% of the biomass of tethered A. spicifera was consumed within one-hour when placed outside Stegastes territories, compared to <5% lost from tethers within territories or herbivore exclusion cages. In situ remote video revealed that tethered A. spicifera located outside territories was grazed primarily by the surgeonfish Acanthurus nigrofuscus (?68% of total bites) and, surprisingly, by S. marginatus (?27% of total bites) that left their territories to feed on this resource on 107 occasions during 400 min of filming. Further, for over half of those occurrences where S. marginatus grazed on the tethered macroalga outside of territories, they fed alongside conspecifics and other species, displaying little of the aggressiveness that characterizes this damselfish. These results show that S. marginatus plays a wider role in determining benthic assemblages than previously recognized, acting both as cultivators of a canopy-forming invasive macroalga within their territories, and as opportunistic browsers in neighboring sites. Consequently, S. marginatus can affect benthic species composition across their territory borders. These results provide a rare example of interspecific facilitation of an exotic alga by an indigenous marine fish. Accounting for fish behaviors more broadly is important to further our understanding of ecological processes that shape reef ecosystems to improve management of MPAs that often support extensive farming damselfish populations. PMID:25329385

Peyton, Kimberly A; Valentino, Lauren M; Maruska, Karen P

2014-01-01

372

Global changes in gene expression by the opportunistic pathogen Burkholderia cenocepacia in response to internalization by murine macrophages  

PubMed Central

Background Burkholderia cenocepacia is an opportunistic pathogen causing life-threatening infections in patients with cystic fibrosis. The bacterium survives within macrophages by interfering with endocytic trafficking and delaying the maturation of the B. cenocepacia-containing phagosome. We hypothesize that B. cenocepacia undergoes changes in gene expression after internalization by macrophages, inducing genes involved in intracellular survival and host adaptation. Results We examined gene expression by intracellular B. cenocepacia using selective capture of transcribed sequences (SCOTS) combined with microarray analysis. We identified 767 genes with significantly different levels of expression by intracellular bacteria, of which 330 showed increased expression and 437 showed decreased expression. Affected genes represented all aspects of cellular life including information storage and processing, cellular processes and signaling, and metabolism. In general, intracellular gene expression demonstrated a pattern of environmental sensing, bacterial response, and metabolic adaptation to the phagosomal environment. Deletion of various SCOTS-identified genes affected bacterial entry into macrophages and intracellular replication. We also show that intracellular B. cenocepacia is cytotoxic towards the macrophage host, and capable of spread to neighboring cells, a role dependent on SCOTS-identified genes. In particular, genes involved in bacterial motility, cobalamin biosynthesis, the type VI secretion system, and membrane modification contributed greatly to macrophage entry and subsequent intracellular behavior of B. cenocepacia. Conclusions B. cenocepacia enters macrophages, adapts to the phagosomal environment, replicates within a modified phagosome, and exhibits cytotoxicity towards the host cells. The analysis of the transcriptomic response of intracellular B. cenocepacia reveals that metabolic adaptation to a new niche plays a major role in the survival of B. cenocepacia in macrophages. This adaptive response does not require the expression of any specific virulence-associated factor, which is consistent with the opportunistic nature of this microorganism. Further investigation into the remaining SCOTS-identified genes will provide a more complete picture of the adaptive response of B. cenocepacia to the host cell environment. PMID:22321740

2012-01-01

373

Cryptic regulation of vasotocin neuronal activity but not anatomy by sex steroids and social stimuli in opportunistic desert finches.  

PubMed

In most vertebrate species, the production of vasotocin (VT; non-mammals) and vasopressin (VP; mammals) in the medial bed nucleus of the stria terminalis (BSTm) waxes and wanes with seasonal reproductive state; however, opportunistically breeding species might need to maintain high levels of this behaviorally relevant neuropeptide year-round in anticipation of unpredictable breeding opportunities. We here provide support for this hypothesis and demonstrate that these neurons are instead regulated 'cryptically' via hormonal regulation of their activity levels, which may be rapidly modified to adjust VT signaling. First, we show that combined treatment of male and female zebra finches (Estrildidae: Taeniopygia guttata) with the androgen receptor antagonist flutamide and the aromatase inhibitor 1,4,6-androstatriene-3,17-dione does not alter the expression of VT immunoreactivity within the BSTm; however, both hormonal treatment and social housing environment (same-sex versus mixed-sex) alter VT colocalization with the immediate early gene product Fos (a proxy marker of neural activation) in the BSTm. In a second experiment, manipulations of estradiol (E2) levels with the aromatase inhibitor letrozole (LET) or subcutaneous E2 implants failed to alter colocalization, suggesting that the colocalization effects in experiment 1 were solely androgenic. LET treatment also did not affect VT immunoreactivity in a manner reversible by E2 treatment. Finally, comparisons of VT immunoreactivity in breeding and nonbreeding individuals of several estrildid species demonstrate that year-round stability of VT immunoreactivity is found only in highly opportunistic species, and is therefore not essential to the maintenance of long-term pair bonds, which are ubiquitous in the Estrildidae. PMID:20332615

Kabelik, David; Morrison, Jenilee A; Goodson, James L

2010-01-01

374

Cryptic Regulation of Vasotocin Neuronal Activity but Not Anatomy by Sex Steroids and Social Stimuli in Opportunistic Desert Finches  

PubMed Central

In most vertebrate species, the production of vasotocin (VT; non-mammals) and vasopressin (VP; mammals) in the medial bed nucleus of the stria terminalis (BSTm) waxes and wanes with seasonal reproductive state; however, opportunistically breeding species might need to maintain high levels of this behaviorally relevant neuropeptide year-round in anticipation of unpredictable breeding opportunities. We here provide support for this hypothesis and demonstrate that these neurons are instead regulated ‘cryptically’ via hormonal regulation of their activity levels, which may be rapidly modified to adjust VT signaling. First, we show that combined treatment of male and female zebra finches (Estrildidae: Taeniopygia guttata) with the androgen receptor antagonist flutamide and the aromatase inhibitor 1,4,6-androstatriene-3,17-dione does not alter the expression of VT immunoreactivity within the BSTm; however, both hormonal treatment and social housing environment (same-sex versus mixed-sex) alter VT colocalization with the immediate early gene product Fos (a proxy marker of neural activation) in the BSTm. In a second experiment, manipulations of estradiol (E2) levels with the aromatase inhibitor letrozole (LET) or subcutaneous E2 implants failed to alter colocalization, suggesting that the colocalization effects in experiment 1 were solely androgenic. LET treatment also did not affect VT immunoreactivity in a manner reversible by E2 treatment. Finally, comparisons of VT immunoreactivity in breeding and nonbreeding individuals of several estrildid species demonstrate that year-round stability of VT immunoreactivity is found only in highly opportunistic species, and is therefore not essential to the maintenance of long-term pair bonds, which are ubiquitous in the Estrildidae. PMID:20332615

Kabelik, David; Morrison, Jenilee A.; Goodson, James L.

2010-01-01

375

Dual Roles of an Algal Farming Damselfish as a Cultivator and Opportunistic Browser of an Invasive Seaweed  

PubMed Central

Herbivory is a fundamental process determining reef resilience, and while algal farming damselfishes can help shape benthic assemblages, an understanding of their contribution to areas outside of defended territories is relatively unexplored. Here, we demonstrate how the farming damselfish Stegastes marginatus plays a dual role in benthic structuring by 1) contributing to persistence of the invasive macroalga Acanthophora spicifera within a Hawaiian marine protected area, where the macroalga occurred exclusively inside Stegastes territories, and 2) behaving as an opportunistic browser of the exotic alga outside their territorial borders. Greater than 50% of the biomass of tethered A. spicifera was consumed within one-hour when placed outside Stegastes territories, compared to <5% lost from tethers within territories or herbivore exclusion cages. In situ remote video revealed that tethered A. spicifera located outside territories was grazed primarily by the surgeonfish Acanthurus nigrofuscus (?68% of total bites) and, surprisingly, by S. marginatus (?27% of total bites) that left their territories to feed on this resource on 107 occasions during 400 min of filming. Further, for over half of those occurrences where S. marginatus grazed on the tethered macroalga outside of territories, they fed alongside conspecifics and other species, displaying little of the aggressiveness that characterizes this damselfish. These results show that S. marginatus plays a wider role in determining benthic assemblages than previously recognized, acting both as cultivators of a canopy-forming invasive macroalga within their territories, and as opportunistic browsers in neighboring sites. Consequently, S. marginatus can affect benthic species composition across their territory borders. These results provide a rare example of interspecific facilitation of an exotic alga by an indigenous marine fish. Accounting for fish behaviors more broadly is important to further our understanding of ecological processes that shape reef ecosystems to improve management of MPAs that often support extensive farming damselfish populations. PMID:25329385

Peyton, Kimberly A.; Valentino, Lauren M.; Maruska, Karen P.

2014-01-01

376

Cutaneous manifestations of opportunistic infections in patients infected with human immunodeficiency virus.  

PubMed Central

Bacillary angiomatosis (BA) presents most commonly as a cutaneous disease and is caused by two organisms. Bartonella (Rochalimaea) henselae and Bartonella (Rochalimaea) quintana. Biopsy confirmation of cutaneous BA is essential because lesions can mimic nodular Kaposi's sarcoma in appearance. Although the vast majority of human immunodeficiency virus (HIV)-infected patients with BA have CD4 lymphocyte counts of less than 100 cells per mm3, the disease responds well to antimicrobial therapy. Staphylococcus aureus is the most common bacterial skin pathogen affecting HIV-infected patients. The prevalence of skin disease due to S. aureus may be explained by high nasal carriage rates for the organism ( > or = 50%) and altered immune function in conjunction with an impaired cutaneous barrier. Herpes simplex virus causes mucocutaneous disease early in the course HIV infection and ulcerative lesions at any site in advanced HIV infection. Herpes zoster is common early in the course of HIV infection; recurrent and disseminated herpes zoster infections are characteristic of patients with advanced HIV disease. Acyclovir resistance is usually seen in patients with large, untreated, ulcerative lesions of herpes simplex virus and in patients with chronic, verrucous lesions of varicella-zoster virus. Cutaneous cryptococcosis, histoplasmosis, and coccidiomycosis are markers of disseminated disease and require biopsy confirmation. Scabies is easily diagnosed but may be atypical in presentation and difficult to eradicate in advanced HIV disease. PMID:7553576

Tappero, J W; Perkins, B A; Wenger, J D; Berger, T G

1995-01-01

377

Power system commonality study  

NASA Astrophysics Data System (ADS)

A limited top level study was completed to determine the commonality of power system/subsystem concepts within potential lunar and Mars surface power system architectures. A list of power system concepts with high commonality was developed which can be used to synthesize power system architectures which minimize development cost. Examples of potential high commonality power system architectures are given in this report along with a mass comparison. Other criteria such as life cycle cost (which includes transportation cost), reliability, safety, risk, and operability should be used in future, more detailed studies to select optimum power system architectures. Nineteen potential power system concepts were identified and evaluated for planetary surface applications including photovoltaic arrays with energy storage, isotope, and nuclear power systems. A top level environmental factors study was completed to assess environmental impacts on the identified power system concepts for both lunar and Mars applications. Potential power system design solutions for commonality between Mars and lunar applications were identified. Isotope, photovoltaic array (PVA), regenerative fuel cell (RFC), stainless steel liquid-metal cooled reactors (less than 1033 K maximum) with dynamic converters, and in-core thermionic reactor systems were found suitable for both lunar and Mars environments. The use of SP-100 thermoelectric (TE) and SP-100 dynamic power systems in a vacuum enclosure may also be possible for Mars applications although several issues need to be investigated further (potential single point failure of enclosure, mass penalty of enclosure and active pumping system, additional installation time and complexity). There are also technical issues involved with development of thermionic reactors (life, serviceability, and adaptability to other power conversion units). Additional studies are required to determine the optimum reactor concept for Mars applications. Various screening criteria (availability, environmental compatibility, mass competitiveness of energy storage, safety, and practicality for the application) were used to define concept applicability for each lunar and Mars application. A screening study resulted in 13 power systems for lunar applications and 15 for Mars applications. A commonality analysis showed several power systems with potentially high commonality (across both lunar and Mars applications). These high commonality systems include d PVA/RFC, dynamic isotope (1033 K Stirling, 1133 K Brayton, and 1300 K Brayton PCU's), SP-100 TE and dynamic derivatives (Mars systems required vacuum enclosure), in-core thermionic reactor, and liquid metal cooled reactor/Stirling cycle (1033 K). The generic commonality results were used to synthesize 3 high commonality power system architectures: (1) predominantly PV (limited nuclear and isotope), (2) predominantly in-core thermionic reactor/DIPS, and (3) predominantly SP-100 reactor/DIPS. The in-core thermionic reactor/DIPS power system architecture had the lowest total mass. Specific outputs from this study included lists of power system requirements, power system candidates, a power system application matrix, power system characteristics (mass), power system commonality ratings, example high commonality power system architectures, architecture masses, and issues/design solutions for lunar/Mars commonality.

Littman, Franklin D.

1992-07-01

378

The Federal Commons  

NSDL National Science Digital Library

In 1999, the Federal Financial Assistance Management Improvement Act was passed in order to force the development of federal electronic grant processing. A result of the legislation, the Federal Commons portal gives "grantees (state and local governments, universities, small businesses, etc.) full service grants processing across all functions in the grant life cycle." While providing only an entrance to various grant institutions and services, the Federal Commons helps to eliminate the maze-like trail that multi-grant projects sometimes must travel to get to grant proposal Web sites. Most physical sciences researchers will find relevant federal departments listed under the Science and Technology link.

379

Detecting a common interpretive framework for impersonal violence: The homology in participants’ rhetoric on sport hunting, “hate crimes,” and stranger rape  

Microsoft Academic Search

Based on the discourse of sport hunters, “hate criminals, “ and stranger rapists, this essay argues that a common interpretive framework rhetorically informs all three activities. The four features of the homology identified are: (a) the rhetor symbolically constructs and physically initiates an adversarial relationship with non?consenting victims\\/prey class members, (b) victims\\/prey class members are selected opportunistically and constructed impersonally

Kathryn M. Olson

2002-01-01

380

Risk assessment of the schmutzdecke of biosand filters: identification of an opportunistic pathogen in schmutzdecke developed by an unsafe water source.  

PubMed

The biosand filter (BSF) is widely applied in developing counties as an appropriate technology-based product for supplying "safe" water. Biosand filters exhibit relatively high purifying efficiency because of the schmutzdecke (biofilm) embedded in them. However, schmutzdecke should be cleaned or discarded on a regular basis to maintain the purifying efficiency of the BSF. Due to its role in BSFs, the purifying function of schmutzdecke, rather than its potential risk when not properly discarded, has so far been the primary focus of research. This study aims to provide a risk assessment of schmutzdecke in an attempt to draw attention to a wholly new angle of schmutzdecke usage. We conducted 16S rRNA gene sequencing and phylogenetic analysis to identify opportunistic pathogens in schmutzdecke developed using water from the Hyung-San River. The results reveal that the schmutzdecke derived from this water source contains diverse and relatively high portions of opportunistic pathogen strains; 55% of all isolates collected from schmutzdecke were identified as opportunistic pathogens. Moreover, the diversity of microorganisms is increased in the schmutzdecke compared to its water source in terms of diversity of genus, phylum and opportunistic pathogen strain. As a whole, our study indicates a potential risk associated with schmutzdecke and the necessity of a solid guideline for the after-treatment of discarded schmutzdecke. PMID:24534769

Hwang, Hyun Gyu; Kim, Min Seo; Shin, Soo Min; Hwang, Cher Won

2014-02-01

381

Acceptability and effectiveness of opportunistic referral of smokers to telephone cessation advice from a nurse: a randomised trial in Australian general practice  

Microsoft Academic Search

BACKGROUND: GPs often lack time to provide intensive cessation advice for patients who smoke. This study aimed to determine the effectiveness of opportunistic referral of smokers by their GP for telephone cessation counselling by a trained nurse. METHODS: Adult smokers (n = 318) attending 30 GPs in South Western Sydney, Australia were randomly allocated to usual care or referral to

Jane M Young; Seham Girgis; Tracey A Bruce; Melissa Hobbs; Jeanette E Ward

2008-01-01

382

Developing an indicator of nutrient enrichment in coastal estuaries and lagoons using tissue nitrogen content of the opportunistic alga, Enteromorpha intestinalis (L. Link)  

Microsoft Academic Search

We explored the use of an opportunistic green alga, Enteromorpha intestinalis (L. Link), as an indicator of N enrichment in a southern California salt marsh. In conjunction with N additions to cordgrass (Spartina foliosa, Trin) in April, June and August 1995, mesh bags containing N-starved algal tissue were placed within cordgrass patches, at their edges along islands, and in adjacent

Peggy Fong; Katharyn E. Boyer; Joy B. Zedler

1998-01-01

383

Risk Assessment of the Schmutzdecke of Biosand Filters: Identification of an Opportunistic Pathogen in Schmutzdecke Developed by an Unsafe Water Source  

PubMed Central

The biosand filter (BSF) is widely applied in developing counties as an appropriate technology-based product for supplying “safe” water. Biosand filters exhibit relatively high purifying efficiency because of the schmutzdecke (biofilm) embedded in them. However, schmutzdecke should be cleaned or discarded on a regular basis to maintain the purifying efficiency of the BSF. Due to its role in BSFs, the purifying function of schmutzdecke, rather than its potential risk when not properly discarded, has so far been the primary focus of research. This study aims to provide a risk assessment of schmutzdecke in an attempt to draw attention to a wholly new angle of schmutzdecke usage. We conducted 16S rRNA gene sequencing and phylogenetic analysis to identify opportunistic pathogens in schmutzdecke developed using water from the Hyung-San River. The results reveal that the schmutzdecke derived from this water source contains diverse and relatively high portions of opportunistic pathogen strains; 55% of all isolates collected from schmutzdecke were identified as opportunistic pathogens. Moreover, the diversity of microorganisms is increased in the schmutzdecke compared to its water source in terms of diversity of genus, phylum and opportunistic pathogen strain. As a whole, our study indicates a potential risk associated with schmutzdecke and the necessity of a solid guideline for the after-treatment of discarded schmutzdecke. PMID:24534769

Hwang, Hyun Gyu; Kim, Min Seo; Shin, Soo Min; Hwang, Cher Won

2014-01-01

384

COMMON CABBAGE VARIETAL TRIAL  

Microsoft Academic Search

Seven common cabbage varieties from 6 different seed companies were evaluated for their yield and other agronomic characters in order to select the good cabbage varieties that have high and stable yield, early and uniform maturity and resistant to soft rot, black rot and mosaic virus diseases. The experiment was conducted from November 23, 1989 to February 12, 1990 in

NGUYEN VAN EM

385

Math, Literacy, & Common Standards  

ERIC Educational Resources Information Center

Nearly every state has signed on to use the Common Core State Standards as a framework for teaching English/language arts and mathematics to students. Translating them for the classroom, however, requires schools, teachers, and students to change the way they approach teaching and learning. This report examines the progress some states have made…

Education Week, 2012

2012-01-01

386

Common clay and shale  

USGS Publications Warehouse

Part of the 2000 annual review of the industrial minerals sector. A general overview of the common clay and shale industry is provided. In 2000, U.S. production increased by 5 percent, while sales or use declined to 23.6 Mt. Despite the slowdown in the economy, no major changes are expected for the market.

Virta, R.L.

2001-01-01

387

Solving Common Mathematical Problems  

NASA Technical Reports Server (NTRS)

Mathematical Solutions Toolset is a collection of five software programs that rapidly solve some common mathematical problems. The programs consist of a set of Microsoft Excel worksheets. The programs provide for entry of input data and display of output data in a user-friendly, menu-driven format, and for automatic execution once the input data has been entered.

Luz, Paul L.

2005-01-01

388

Common clay and shale  

USGS Publications Warehouse

Part of the 2002 industrial minerals review. The production, consumption, and price of shale and common clay in the U.S. during 2002 are discussed. The impact of EPA regulations on brick and structural clay product manufacturers is also outlined.

Virta, R.L.

2003-01-01

389

Common Standards for All  

ERIC Educational Resources Information Center

About three-fourths of the states have already adopted the Common Core State Standards, which were designed to provide more clarity about and consistency in what is expected of student learning across the country. However, given the brief time since the standards' final release in June, questions persist among educators, who will have the…

Principal, 2010

2010-01-01

390

COMMON LISP: The language  

Microsoft Academic Search

This book describes COMMON LISP,which is becoming the industry and government standard AI language. Topics covered include the following: data types; scope and extent; type specifiers; program structure; predicates; control structure; macros; declarations; symbols; packages; numbers; characters; sequences; lists; hash tables; arrays; strings; structures; the evaluator; streams; input\\/output; file system interface; and errors.

G. L. Steele; G. L. Jr

1984-01-01

391

Human Commonalities and Art  

ERIC Educational Resources Information Center

Educator Ernest Boyer believed that well-educated students should do more than master isolated facts. They should understand the "connectedness of things." He suggested organizing curriculum thematically around eight commonalities shared by people around the world. In the book "The Basic School: A Community for Learning," Boyer recommends that…

Passmore, Kaye

2008-01-01

392

Common dermatoses of infancy.  

PubMed

Within the pediatric population of their practices, family physicians frequently encounter infants with skin rashes. This article discusses several of the more common rashes of infancy: atopic dermatitis, cradle cap, diaper dermatitis and miliaria. Etiology, clinical picture and possible approaches to treatment are presented. PMID:21267297

Gora, I

1986-09-01

393

Common Misconceptions about Cholesterol  

MedlinePLUS

Common Misconceptions about Cholesterol Updated:May 29,2014 Cholesterol can be both good and bad, so it's important to learn the facts about ... misconceptions about cholesterol. Click on each misconception about cholesterol to see the truth: My choices about diet ...

394

For Research Common Research  

E-print Network

PET Scans For Research Common Research Procedures: PET Scans What is Positron Emission Tomography: 1. Is this PET scan being done specifically for the research study or is it also a part of my purposes and is not intended to provide medical advice. Talk with your doctor or research team before

Church, George M.

395

A Common Language  

Microsoft Academic Search

This article describes the experience and motivation that drove the specific solutions developed for LIPA's EIM and data management strategy. LIPA's EIM has at its core a common information model (CIM)-based enterprise semantic model (ESM), a customized software development life cycle (SDLC), process templates, and LIPA's IT technical architecture design. Data modeling and technical architecture are based wherever possible on

M. Hervey; P. Vujovic

2010-01-01

396

Common Buckwheat Ecotypes  

Microsoft Academic Search

Series of laboratory experiments were conducted at Biotechnology laboratory of the Research Centre for Applied Science & Technology of Tribhuvan University at Kathmandu during 1993­ 1994 to optimize the culture media for rapid multiplication of identical biotypes of determinate Nepalese common buckwheat genotypes using leaf and stem explants. The experimental results showed that the maximum callus induction frequency, irrespective of

B. P. Rajbhandari; S. Dhaubhadel; D. M. Gautam; B. R. Gautam

397

Common manned module  

NASA Technical Reports Server (NTRS)

An economic analysis examines a reusable single crew module to reduce the cost of Moon to stay exploration by 5 billion dollars. Topics covered in viewgraph format include the following: aerodynamics, weight, runway landing, technology support, and common module reentry requirements.

Andrews, Dana

1992-01-01

398

Prebreeding in Common Bean  

E-print Network

to achieve an optimum amino acid balance in the diet (Bressani, 1983). Recently, some bean seed properties diabetes. In this regard, positive char- acteristics of bean seeds include the presence of essentialPrebreeding in Common Bean and Use of Genetic Diversity from Wild Germplasm JORGE A. ACOSTA

Gepts, Paul

399

Navagating the Common Core  

ERIC Educational Resources Information Center

This article presents a debate over the Common Core State Standards Initiative as it has rocketed to the forefront of education policy discussions around the country. The author contends that there is value in having clear cross state standards that will clarify the new online and blended learning that the growing use of technology has provided…

McShane, Michael Q.

2014-01-01

400

Space station commonality analysis  

NASA Technical Reports Server (NTRS)

This study was conducted on the basis of a modification to Contract NAS8-36413, Space Station Commonality Analysis, which was initiated in December, 1987 and completed in July, 1988. The objective was to investigate the commonality aspects of subsystems and mission support hardware while technology experiments are accommodated on board the Space Station in the mid-to-late 1990s. Two types of mission are considered: (1) Advanced solar arrays and their storage; and (2) Satellite servicing. The point of departure for definition of the technology development missions was a set of missions described in the Space Station Mission Requirements Data Base. (MRDB): TDMX 2151 Solar Array/Energy Storage Technology; TDMX 2561 Satellite Servicing and Refurbishment; TDMX 2562 Satellite Maintenance and Repair; TDMX 2563 Materials Resupply (to a free-flyer materials processing platform); TDMX 2564 Coatings Maintenance Technology; and TDMX 2565 Thermal Interface Technology. Issues to be addressed according to the Statement of Work included modularity of programs, data base analysis interactions, user interfaces, and commonality. The study was to consider State-of-the-art advances through the 1990s and to select an appropriate scale for the technology experiments, considering hardware commonality, user interfaces, and mission support requirements. The study was to develop evolutionary plans for the technology advancement missions.

1988-01-01

401

Common medical pains  

PubMed Central

Pain in infancy and childhood is extremely common. Sources of pain include illness, injury, and medical and dental procedures. Over the past two decades, tremendous progress has been made in the assessment, prevention and treatment of pain. It is important for the paediatric health care provider to be aware of the implications and consequences of pain in childhood. A multitude of interventions are available to reduce or alleviate pain in children of all ages, including neonates. These include behavioural and psychological methods, as well as a host of pharmacological preparations, which are safe and effective when used as indicated. Many complementary and alternative treatments appear to be promising in treating and relieving pain, although further research is required. The present article reviews the most common sources of pain in childhood and infancy, as well as current treatment strategies and options. PMID:19030348

Jacobson, Sheila

2007-01-01

402

Common tester platform concept.  

SciTech Connect

This report summarizes the results of a case study on the doctrine of a common tester platform, a concept of a standardized platform that can be applicable across the broad spectrum of testing requirements throughout the various stages of a weapons program, as well as across the various weapons programs. The common tester concept strives to define an affordable, next-generation design that will meet testing requirements with the flexibility to grow and expand; supporting the initial development stages of a weapons program through to the final production and surveillance stages. This report discusses a concept investing key leveraging technologies and operational concepts combined with prototype tester-development experiences and practical lessons learned gleaned from past weapons programs.

Hurst, Michael James

2008-05-01

403

Common anorectal disorders.  

PubMed

Anorectal disorders result in many visits to healthcare specialists. These disorders include benign conditions such as hemorrhoids to more serious conditions such as malignancy; thus, it is important for the clinician to be familiar with these disorders as well as know how to conduct an appropriate history and physical examination. This article reviews the most common anorectal disorders, including hemorrhoids, anal fissures, fecal incontinence, proctalgia fugax, excessive perineal descent, and pruritus ani, and provides guidelines on comprehensive evaluation and management. PMID:24987313

Foxx-Orenstein, Amy E; Umar, Sarah B; Crowell, Michael D

2014-05-01

404

Common Skin Cancers  

PubMed Central

Melanoma, basal cell carcinoma, and squamous cell carcinoma are the three most common forms of skin cancer. The incidence of skin cancer is increasing at an alarming rate. Early detection is the key to successful management. In this article, the salient clinical features and diagnostic clues for these tumors and their precursor lesions are presented. Current management guidelines are also discussed. ImagesFigure 1Figures 2-3Figures 4-6Figures 7-9 PMID:21221380

Ho, Vincent C.

1992-01-01

405

Common Anorectal Disorders  

PubMed Central

Anorectal disorders result in many visits to healthcare specialists. These disorders include benign conditions such as hemorrhoids to more serious conditions such as malignancy; thus, it is important for the clinician to be familiar with these disorders as well as know how to conduct an appropriate history and physical examination. This article reviews the most common anorectal disorders, including hemorrhoids, anal fissures, fecal incontinence, proctalgia fugax, excessive perineal descent, and pruritus ani, and provides guidelines on comprehensive evaluation and management. PMID:24987313

Foxx-Orenstein, Amy E.; Umar, Sarah B.; Crowell, Michael D.

2014-01-01

406

Digital Resource Commons  

NSDL National Science Digital Library

The Ohio Digital Resource Commons (DRC) is a place to learn about the historic, instructional, cultural, and creative works of those in the Ohio University system, as well as the liberal arts colleges of Ohio. Although not all of the Ohio schools save material with the DRC, many of them elect to do so. Higher education institutions, as well as K-12 institutions are allowed to save their work via the central network, as long as the work has archival merit. Visitors will want to click on "Communities and Collections" on the left hand menu to browse the vast resources available. Some of the communities included are "Art and Architecture", "Multi-Subject Video", and "OhioLINK Electronic Thesis and Dissertation Center". Within each community are some notable collections including, "Archaeological Atlas of Ohio", "Encyclopedia of Physics Demonstrations", and the "Kent State Shootings Oral Histories". In order to see a list of the archives available to search, visitors should click on "Advanced Search", under the blank search box near the top of the page. The scrollable box next to the archives category includes such choices as "Oberlin Digital Commons", "Scholarly Commons at Miami University", and "Digital Archive of Literacy Narratives".

407

Boston University Digital Common  

NSDL National Science Digital Library

Boston University has a range of scholars, from those who research the hospitality field to others who are fascinated by the world of photonics. The University's Digital Common Repository contains thousands of documents and publications that span this wide range, authored or co-authored by BU faculty, students, and staff. The different communities here are divided into sections that include College of Arts and Sciences, Centers & Institutes, and Metropolitan College. Visitors will find religious sermons, pieces of music, working economics papers, and a vast cornucopia of other materials. Also, visitors are encouraged to use the Browse feature to look for documents by title, subject, author, or date.

408

Common Southeast Wetland Plants Common name1,2  

E-print Network

capensis No common rush Juncus effuses Seed rice cut grass Leersia oryzoides Seed common duckweed Lemna minor Aquatic Vegetation, Inverts sprangletop Leptochloa panacea Seed cardinal flower Lobelia cardinalis

Gray, Matthew

409

Exploring the Unique N-Glycome of the Opportunistic Human Pathogen Acanthamoeba*  

PubMed Central

Glycans play key roles in host-pathogen interactions; thus, knowing the N-glycomic repertoire of a pathogen can be helpful in deciphering its methods of establishing and sustaining a disease. Therefore, we sought to elucidate the glycomic potential of the facultative amoebal parasite Acanthamoeba. This is the first study of its asparagine-linked glycans, for which we applied biochemical tools and various approaches of mass spectrometry. An initial glycomic screen of eight strains from five genotypes of this human pathogen suggested, in addition to the common eukaryotic oligomannose structures, the presence of pentose and deoxyhexose residues on their N-glycans. A more detailed analysis was performed on the N-glycans of a genotype T11 strain (4RE); fractionation by HPLC and tandem mass spectrometric analyses indicated the presence of a novel mannosylfucosyl modification of the reducing terminal core as well as phosphorylation of mannose residues, methylation of hexose and various forms of pentosylation. The largest N-glycan in the 4RE strain contained two N-acetylhexosamine, thirteen hexose, one fucose, one methyl, and two pentose residues; however, in this and most other strains analyzed, glycans with compositions of Hex8–9HexNAc2Pnt0–1 tended to dominate in terms of abundance. Although no correlation between pathogenicity and N-glycan structure can be proposed, highly unusual structures in this facultative parasite can be found which are potential virulence factors or therapeutic targets. PMID:23139421

Schiller, Birgit; Makrypidi, Georgia; Razzazi-Fazeli, Ebrahim; Paschinger, Katharina; Walochnik, Julia; Wilson, Iain B. H.

2012-01-01

410

A Five-Year Survey of Dematiaceous Fungi in a Tropical Hospital Reveals Potential Opportunistic Species  

PubMed Central

Dematiaceous fungi (black fungi) are a heterogeneous group of fungi present in diverse environments worldwide. Many species in this group are known to cause allergic reactions and potentially fatal diseases in humans and animals, especially in tropical and subtropical climates. This study represents the first survey of dematiaceous fungi in Malaysia and provides observations on their diversity as well as in vitro response to antifungal drugs. Seventy-five strains isolated from various clinical specimens were identified by morphology as well as an internal transcribed spacer (ITS)-based phylogenetic analysis. The combined molecular and conventional approach enabled the identification of three classes of the Ascomycota phylum and 16 genera, the most common being Cladosporium, Cochliobolus and Neoscytalidium. Several of the species identified have not been associated before with human infections. Among 8 antifungal agents tested, the azoles posaconazole (96%), voriconazole (90.7%), ketoconazole (86.7%) and itraconazole (85.3%) showed in vitro activity (MIC ?1 µg/mL) to the largest number of strains, followed by anidulafungin (89.3%), caspofungin (74.7%) and amphotericin B (70.7%). Fluconazole appeared to be the least effective with only 10.7% of isolates showing in vitro susceptibility. Overall, almost half (45.3%) of the isolates showed reduced susceptibility (MIC >1 µg/mL) to at least one antifungal agent, and three strains (one Pyrenochaeta unguis-hominis and two Nigrospora oryzae) showed potential multidrug resistance. PMID:25098697

Yew, Su Mei; Chan, Chai Ling; Lee, Kok Wei; Na, Shiang Ling; Tan, Ruixin; Hoh, Chee-Choong; Yee, Wai-Yan; Ngeow, Yun Fong; Ng, Kee Peng

2014-01-01

411

Commonly used gastrointestinal drugs.  

PubMed

This chapter reviews the spectrum and mechanisms of neurologic adverse effects of commonly used gastrointestinal drugs including antiemetics, promotility drugs, laxatives, antimotility drugs, and drugs for acid-related disorders. The commonly used gastrointestinal drugs as a group are considered safe and are widely used. A range of neurologic complications are reported following use of various gastrointestinal drugs. Acute neurotoxicities, including transient akathisias, oculogyric crisis, delirium, seizures, and strokes, can develop after use of certain gastrointestinal medications, while disabling and pervasive tardive syndromes are described following long-term and often unsupervised use of phenothiazines, metoclopramide, and other drugs. In rare instances, some of the antiemetics can precipitate life-threatening extrapyramidal reactions, neuroleptic malignant syndrome, or serotonin syndrome. In contrast, concerns about the cardiovascular toxicity of drugs such as cisapride and tegaserod have been grave enough to lead to their withdrawal from many world markets. Awareness and recognition of the neurotoxicity of gastrointestinal drugs is essential to help weigh the benefit of their use against possible adverse effects, even if uncommon. Furthermore, as far as possible, drugs such as metoclopramide and others that can lead to tardive dyskinesias should be used for as short time as possible, with close clinical monitoring and patient education. PMID:24365343

Aggarwal, Annu; Bhatt, Mohit

2014-01-01

412

Endotracheal tube biofilm inoculation of oral flora and subsequent colonization of opportunistic pathogens.  

PubMed

Endotracheal (ET) tubes accumulate a biofilm during use, which can harbor potentially pathogenic microorganisms. The enrichment of pathogenic strains in the biofilm may lead to ventilator-associated pneumonia (VAP) with an increased morbidity rate in intensive care units. We used quantitative PCR (qPCR) and gene surveys targeting 16S rRNA genes to quantify and identify the bacterial community to detect fastidious/nonculturable organisms present among extubated ET tubes. We collected eight ET tubes with intubation periods between 12 h and 23 d from different patients in a surgical and a medical intensive care unit. Our qPCR data showed that ET tubes were colonized within 24 h. However, the variation between patients was too high to find a positive correlation between the bacterial load and intubation period. We obtained 1263 near full-length 16S rRNA gene sequences from the diverse bacterial communities. Over 70% of these sequences were associated with genera of typical oral flora, while only 6% were associated with gastrointestinal flora. The most common genus identified was Streptococcus (348/1263), followed by Prevotella (179/1263), and Neisseria (143/1263) with the highest relative concentrations for ET tubes with short intubation periods, indicating oral inoculation of the ET tubes. Our study also shows that even though potentially pathogenic bacteria existed in ET tube biofilms within 24 h of intubation, a longer intubation period increases the opportunity for these organisms to proliferate. In the ET tube that was in place for 23 d, 95% of the sequences belonged to Pseudomonas aeruginosa, which is a bacterial pathogen that is known to out compete commensal bacteria in biofilms, especially during periods of antibiotic treatment. Harboring such pathogens in ET biofilms may increase the chance of VAP, and should be aggressively monitored and prevented. PMID:20510651

Perkins, Sarah D; Woeltje, Keith F; Angenent, Largus T

2010-11-01

413

Common Approaches in Critical Care  

MedlinePLUS

... Home Clinical Critical Care Information for Patients | | More Common Approaches in Critical Care Information for Patients Introduction General Information Common Illnesses of Critically Ill Patients ICU Devices and ...

414

Clinical Significance of Filamentous Basidiomycetes Illustrated by Isolates of the Novel Opportunist Ceriporia lacerata from the Human Respiratory Tract  

PubMed Central

The filamentous basidiomycete Ceriporia lacerata, an agent of white rot on wood, has never been reported in human disease and its clinical significance is not yet known. We describe 4 patients with respiratory diseases where C. lacerata was implicated in a wide spectrum of clinical manifestations ranging from saprobic colonization to fungal pneumonia. The isolates did not show the morphological characteristics that facilitate recognition of filamentous basidiomycetes, such as the presence of clamp connections, spicules along hyphae, or fruiting bodies. The identity of the mold was confirmed by sequencing the internal transcribed spacer 1 and 4 (ITS-1 and ITS-4) and D1/D2 regions of the rRNA gene. All of the isolates exhibited the lowest MICs of posaconazole and isavuconazole (MIC range, 0.06 to 0.125 ?g/ml), followed by itraconazole (MIC range, 0.06 to 0.5 ?g/ml), voriconazole (MIC range, 0.125 to 0.5 ?g/ml), and amphotericin B (MIC range, 0.25 to 1 ?g/ml). The infections reported here occurred in patients with preexisting lung damage induced by tuberculosis or chronic obstructive pulmonary disease. Chronic, sometimes fatal infections by the ascomycete Aspergillus fumigatus and the basidiomycete Schizophyllum commune are well established in the presence of an anatomical pulmonary defect or in the background of immunodeficiency. It is postulated that C. lacerata, a novel opportunist basidiomycete, may be involved in similar pathological processes. PMID:23241374

Agarwal, Kshitij; Kathuria, Shallu; Singh, Pradeep Kumar; Roy, P.; Gaur, S. N.; de Hoog, G. S.; Meis, Jacques F.

2013-01-01

415

Opportunistic Autoimmune Disorders Potentiated by Immune-Checkpoint Inhibitors Anti-CTLA-4 and Anti-PD-1  

PubMed Central

To improve the efficacy of immunotherapy for cancer and autoimmune diseases, recent ongoing and completed clinical trials have focused on specific targets to redirect the immune network toward eradicating a variety of tumors and ameliorating the self-destructive process. In a previous review, both systemic immunomodulators and monoclonal antibodies (mAbs), anti-CTLA-4, and anti-CD52, were discussed regarding therapeutics and autoimmune sequelae, as well as predisposing factors known to exacerbate immune-related adverse events (irAEs). This review will focus on immune-checkpoint inhibitors, and the data from most clinical trials involve blockade with anti-CTLA-4 such as ipilimumab. However, despite the mild to severe irAEs observed with ipilimumab in ~60% of patients, overall survival (OS) averaged ~22–25% at 3–5?years. To boost OS, other mAbs targeting programed death-1 and its ligand are undergoing clinical trials as monotherapy or dual therapy with anti-CTLA-4. Therapeutic combinations may generate different spectrum of opportunistic autoimmune disorders. To simulate clinical scenarios, we have applied regulatory T cell perturbation to murine models combined to examine the balance between thyroid autoimmunity and tumor-specific immunity. PMID:24904570

Kong, Yi-chi M.; Flynn, Jeffrey C.

2014-01-01

416

Conserved natural IgM antibodies mediate innate and adaptive immunity against the opportunistic fungus Pneumocystis murina.  

PubMed

Host defense against opportunistic fungi requires coordination between innate and adaptive immunity for resolution of infection. Antibodies generated in mice vaccinated with the fungus Pneumocystis prevent growth of Pneumocystis organisms within the lungs, but the mechanisms whereby antibodies enhance antifungal host defense are poorly defined. Nearly all species of fungi contain the conserved carbohydrates ?-glucan and chitin within their cell walls, which may be targets of innate and adaptive immunity. In this study, we show that natural IgM antibodies targeting these fungal cell wall carbohydrates are conserved across many species, including fish and mammals. Natural antibodies bind fungal organisms and enhance host defense against Pneumocystis in early stages of infection. IgM antibodies influence recognition of fungal antigen by dendritic cells, increasing their migration to draining pulmonary lymph nodes. IgM antibodies are required for adaptive T helper type 2 (Th2) and Th17 cell differentiation and guide B cell isotype class-switch recombination during host defense against Pneumocystis. These experiments suggest a novel role for the IgM isotype in shaping the earliest steps in recognition and clearance of this fungus. We outline a mechanism whereby serum IgM, containing ancient specificities against conserved fungal antigens, bridges innate and adaptive immunity against fungal organisms. PMID:21149550

Rapaka, Rekha R; Ricks, David M; Alcorn, John F; Chen, Kong; Khader, Shabaana A; Zheng, Mingquan; Plevy, Scott; Bengtén, Eva; Kolls, Jay K

2010-12-20

417

Seasonal changes in brain GnRH immunoreactivity and song-control nuclei volumes in an opportunistically breeding songbird.  

PubMed

White-winged crossbills (Loxia leucoptera) are opportunistic breeders that can nest at almost any time of year if there is sufficient food. Other cardueline finches that have been shown to breed on a strictly seasonal schedule become absolutely refractory to the stimulatory effects of long-day photoperiod, dramatically down-regulate hypothalamic gonadotropin-releasing hormone (GnRH), and reduce the volume of several song-control nuclei in autumn. This study examined whether changes in photoperiod modify the GnRH and song-control systems in white-winged crossbills. Adult male and female crossbills were captured and held on a naturally changing photoperiod. Brains of male and female birds were collected in May, October, and January. GnRH content was assessed by immunocytochemistry and the volumes of Nissl-defined song-control nuclei (HVc, Area X, and the robust nucleus of the archistriatum) were reconstructed. In contrast to other cardueline finches, GnRH immunoreactivity was relatively stable across the year, exhibiting only modest seasonal variation. The song control system, on the other hand, exhibited large seasonal changes as well as sex differences. Thus, crossbills appear to maintain hypothalamic GnRH content year round, perhaps to facilitate a rapid response to favorable breeding conditions, even on short days. However, song control nuclei are dramatically affected by photoperiod. Future work should examine these systems in crossbills breeding on short days to compare photoperiod-dependent and -independent effects on neural plasticity. PMID:11799277

MacDougall-Shackleton, S A; Deviche, P J; Crain, R D; Ball, G F; Hahn, T P

2001-01-01

418

Growth promotion of the opportunistic human pathogen, Staphylococcus lugdunensis, by heme, hemoglobin, and coculture with Staphylococcus aureus  

PubMed Central

Staphylococcus lugdunensis is both a commensal of humans and an opportunistic pathogen. Little is currently known about the molecular mechanisms underpinning the virulence of this bacterium. Here, we demonstrate that in contrast to S. aureus,S. lugdunensis makes neither staphyloferrin A (SA) nor staphyloferrin B (SB) in response to iron deprivation, owing to the absence of the SB gene cluster, and a large deletion in the SA biosynthetic gene cluster. As a result, the species grows poorly in serum-containing media, and this defect was complemented by introduction of the S. aureusSA gene cluster into S. lugdunensis. S. lugdunensis expresses the HtsABC and SirABC transporters for SA and SB, respectively; the latter gene set is found within the isd (heme acquisition) gene cluster. An isd deletion strain was significantly debilitated for iron acquisition from both heme and hemoglobin, and was also incapable of utilizing ferric-SB as an iron source, while an hts mutant could not grow on ferric-SA as an iron source. In iron-restricted coculture experiments, S. aureus significantly enhanced the growth of S. lugdunensis, in a manner dependent on staphyloferrin production by S. aureus, and the expression of the cognate transporters by S. lugdunensis. PMID:24515974

Brozyna, Jeremy R; Sheldon, Jessica R; Heinrichs, David E

2014-01-01

419

Benzothieno[3,2-b]quinolinium and 3-(Phenylthio)quinolinium Compounds: Synthesis and Evaluation against Opportunistic Fungal Pathogens  

PubMed Central

Substitution around 5-methyl benzothieno[3,2-b]quinolinium (2) ring system was explored in order to identify positions of substitution that could improve its antifungal profile. The 3-methoxy (10b) was active against C. albicans, C. neoformans and A. fumigatus and the 4-chloro (10f) analog showed moderate increases in anti-cryptococcal and anti-aspergillus activities. The effectiveness of 10b and 10f were validated in murine models of candidiasis and cryptococcosis respectively. The efficacy of 10f in reducing brain cryptococcal infection and its observation in the brain of mice injected with this quaternary compound confirm the capacity of these compounds to cross the blood-brain barrier of mice. Overall, several of the chloro and methoxy substituted compounds showed significant improvements in activity against A. fumigatus, the fungal pathogen prevalent in patients receiving organ transplant. Opening the benzothiophene ring of 2 to form 1-(5-cyclohexylpentyl)-3-(phenylthio)quinolinium compound (3) resulted in the identification of several novel compounds with over 50-fold increases in potency (cf 2) while retaining low cytotoxicities. Thus, compound 3 constitutes a new scaffold for development of drugs against opportunistic infections. PMID:21134759

Boateng, Comfort A.; Eyunni, Suresh V. K.; Zhu, Xue Y.; Etukala, Jagan R.; Bricker, Barbara A.; Ashfaq, M. K.; Jacob, Melissa R.; Khan, Shabana I.; Walker, Larry A.; Ablordeppey, Seth Y.

2010-01-01

420

[Common variable immunodeficiency].  

PubMed

Common variable immunodeficiency (CVI) is a heterogeneous syndrome characterized by defective antibody formation, resulting in abnormally low serum immunoglobulin levels. Clinical presentation usually includes recurrent infections of the respiratory tract, mostly induced by capsular bacteria. Patients are also highly prone to Giardia lamblia infections and related gastrointestinal disorders, as well as to a variety of autoimmune diseases which appear in approximately 20% of them. In addition, CVI can be frequently associated with a non-Hodgkin lymphoma or gastric carcinoma. In spite of its relatively frequent occurrence, the pathogenesis of CVI still remains poorly defined. In this review the authors describe clinical features, immunological abnormalities and replacement treatment with intravenous immunoglobulins of this antibody deficiency syndrome. PMID:9102704

Silvestris, N; Silvestris, F; Russo, S; Dammacco, F

1996-12-01

421

National PTA Common Sense  

NSDL National Science Digital Library

The US National Parents and Teachers Association, in conjunction with GTE Corporation, furnishes this site, an information hub for the promotion of drug- and alcohol-free children. Presently, the site is divided into three sections of both serious and fun activities. The Parent's Center consists of interactive quizzes and tip sheets related to developing drug awareness, being a role model, and getting involved in your kids' activities. Visitors to the Family Room will find activities to help kids with their self-esteem, as well as teach them drug-awareness. Family games, quizzes, and cartoons are also available. Help and Hotlines points to organizations that can provide further support and information (links are provided), as well as books and videos. Finally, the site includes an interactive poll, several bulletin boards (registration required), and information for PTA leaders, highlighted by a library of resources to help spread the common sense message.

422

Sporotrichosis: An Emerging Neglected Opportunistic Infection in HIV-Infected Patients in Rio de Janeiro, Brazil  

PubMed Central

Sporotrichosis associated with zoonotic transmission remains a relevant public health problem in Rio de Janeiro, Brazil, affecting a large at-risk population, which includes HIV-infected individuals. We assessed patients co-infected by Sporothrix spp. and HIV over time in the context of an unabated sporotrichosis epidemic. A retrospective cohort retrieved information from a National reference institute for infectious diseases regarding 48 patients with sporotrichosis-HIV co-infection (group 1) as well as 3,570 patients with sporotrichosis (group 2), from 1987 through March 2013. Most patients from group 1 were male (68.8%), whereas women were predominant in group 2 (69.1%; p<0.0001). Patients from group 1 were younger than those from group 2 (??=?38.38±10.17 vs. 46.34±15.85; p<0.001) and differed from group 2 in terms of their race/ethnic background, with 70.8% non-white patients in group 1 vs. 38.6% from group 2 (p<0.0001). Close to half (?44%) of the patients from group 1 were hospitalized due to sporotrichosis over time, whereas hospitalization was very unlikely in group 2, among whom approximately 1% were hospitalized over time. Dissemination of sporotrichosis was the main cause of hospitalization in both groups, although it was more common among hospitalized patients from group 1 (19/21 [90.5%] vs. 16/37 [43.2%]; p<0.001). Over the period under analysis, eight patients died due to sporotrichosis (3/48 vs. 5/3,570). The diagnosis of sporotrichosis elicited HIV testing and subsequent diagnosis in 19/48 patients, whereas 23/48 patients were simultaneously diagnosed with the two infections. HIV infection aggravates sporotrichosis, with a higher incidence of severe disseminated cases and a higher number of hospitalizations and deaths. Underserved populations, among whom sporotrichosis has been propagated, have been affected by different transmissible (e.g., HIV) and non-transmissible diseases. These populations should be targeted by community development programs and entitled to integrated management and care of their superimposed burdens. PMID:25166475

Freitas, Dayvison Francis Saraiva; do Valle, Antonio Carlos Francesconi; da Silva, Margarete Bernardo Tavares; Campos, Dayse Pereira; Lyra, Marcelo Rosandiski; de Souza, Rogerio Valls; Veloso, Valdilea Goncalves; Zancope-Oliveira, Rosely Maria; Bastos, Francisco Inacio; Galhardo, Maria Clara Gutierrez

2014-01-01

423

Chlamydia Screening in Ireland: a pilot study of opportunistic screening for genital Chlamydia trachomatis infection in Ireland (2007-2009). Pre-screening Report  

Microsoft Academic Search

Summary\\u000aA series of background studies in 18 to 29 year olds were conducted in a range of primary care settings in Dublin and Galway, 2007-09, to assess the acceptability and feasibility of opportunistic screening for chlamydia:\\u000a- semi-structured interviews with 35 women who had never been tested for a sexually transmitted infection (STI)\\u000a- similar interviews with 30 men

Myles Balfe; Ruairi Brugha; Emer OConnell; Deirdre Vaughan; Diarmuid ODonovan; Claire Coleman; Ronan Conroy; Martin Cormican; Margaret Fitzgerald; Catherine Fleming; Hannah McGee; Andrew Murphy; Grainne Ni Fhoghlu; Ciaran ONeill; Paddy Gillespie

2012-01-01

424

Plant competition, abiotic, and long- and short-term effects of large herbivores on demography of opportunistic species in a semiarid grassland  

Microsoft Academic Search

The emergence and subsequent survival and growth of five opportunistic “weeds” were monitored after seed additions to long-term grazing treatments with or without current-year grazing, long-term ungrazed treatments, and removal treatments designed to eliminate plant competition from existing perennials while either leaving vegetation and soil structure unaltered or disturbed. The treatments were applied on both uplands and lowlands to assess

D. G. Milchunas; W. K. Lauenroth; P. L. Chapman

1992-01-01

425

Common Control System Vulnerability  

SciTech Connect

The Control Systems Security Program and other programs within the Idaho National Laboratory have discovered a vulnerability common to control systems in all sectors that allows an attacker to penetrate most control systems, spoof the operator, and gain full control of targeted system elements. This vulnerability has been identified on several systems that have been evaluated at INL, and in each case a 100% success rate of completing the attack paths that lead to full system compromise was observed. Since these systems are employed in multiple critical infrastructure sectors, this vulnerability is deemed common to control systems in all sectors. Modern control systems architectures can be considered analogous to today's information networks, and as such are usually approached by attackers using a common attack methodology to penetrate deeper and deeper into the network. This approach often is composed of several phases, including gaining access to the control network, reconnaissance, profiling of vulnerabilities, launching attacks, escalating privilege, maintaining access, and obscuring or removing information that indicates that an intruder was on the system. With irrefutable proof that an external attack can lead to a compromise of a computing resource on the organization's business local area network (LAN), access to the control network is usually considered the first phase in the attack plan. Once the attacker gains access to the control network through direct connections and/or the business LAN, the second phase of reconnaissance begins with traffic analysis within the control domain. Thus, the communications between the workstations and the field device controllers can be monitored and evaluated, allowing an attacker to capture, analyze, and evaluate the commands sent among the control equipment. Through manipulation of the communication protocols of control systems (a process generally referred to as ''reverse engineering''), an attacker can then map out the control system processes and functions. With the detailed knowledge of how the control data functions, as well as what computers and devices communicate using this data, the attacker can use a well known Man-in-the-Middle attack to perform malicious operations virtually undetected. The control systems assessment teams have used this method to gather enough information about the system to craft an attack that intercepts and changes the information flow between the end devices (controllers) and the human machine interface (HMI and/or workstation). Using this attack, the cyber assessment team has been able to demonstrate complete manipulation of devices in control systems while simultaneously modifying the data flowing back to the operator's console to give false information of the state of the system (known as ''spoofing''). This is a very effective technique for a control system attack because it allows the attacker to manipulate the system and the operator's situational awareness of the perceived system status. The three main elements of this attack technique are: (1) network reconnaissance and data gathering, (2) reverse engineering, and (3) the Man-in-the-Middle attack. The details of this attack technique and the mitigation techniques are discussed.

Trent Nelson

2005-12-01

426

Propensity to high-fat diet-induced obesity in mice is associated with the indigenous opportunistic bacteria on the interior of Peyer's patches  

PubMed Central

Indigenous opportunistic bacteria on the interior of the Peyer’s patches play a key role in the development of the mucosal immune, but their population composition has been ignored. The present study was conducted to test the hypothesis that the changes in the composition of indigenous opportunistic bacteria in the Peyer’s patches are associated with obesity. C57BL/6J-male mice had been fed either a control diet or a high-fat diet. After 25 weeks, mice in high-fat diet exhibit either an obesity-prone (OP) or an obesity-resistant (OR) phenotype. Control diet group (CT) and OR group had a significant larger bacteria diversity than that in the OP group. Allobaculum and Lactobacillus were significantly decreased in high-fat diet induced OP mice compared with CT and OR mice, whereas Rhizobium and Lactococcus was significantly increased. The result of quantitative real-time PCR was consistent with that of 454 pyrosequencing. Significant correlations between mRNA expression of inflammation marks and the top 5 abundance genera bacteria on the interior of Peyer’s patches were observed by Pearson’s correlation analysis. Taken together, the indigenous opportunistic bacteria on the interior of Peyer’s patches plays a major role in the development of inflammation for an occurrence of obesity.

Qiao, Yi; Sun, Jin; Xie, Zhenxing; Shi, Yonghui; Le, Guowei

2014-01-01

427

Cellular Compartments of Human Immunodeficiency Virus Type 1 Replication In Vivo: Determination by Presence of Virion-Associated Host Proteins and Impact of Opportunistic Infection  

PubMed Central

Antigens derived from host cells are detectable in the envelope of human immunodeficiency virus type 1 (HIV-1) and result in a distinctive viral phenotype reflecting that of the host cell. An immunomagnetic capture assay targeting discriminatory host proteins was developed to differentiate between HIV-1 derived from macrophages and lymphocytes. HIV-1 propagated in macrophages or lymphocytes in vitro was selectively captured by monoclonal antibodies directed against the virally incorporated cell-type-specific host markers CD36 (macrophages) and CD26 (lymphocytes). Furthermore, by targeting these markers, virus of defined cellular origin was selectively captured from a mixed pool of in vitro-propagated viruses. This technique was further refined in order to determine the impact of opportunistic infection on HIV-1 expression from these cellular compartments in vivo. Analysis of cell-free virus purified from plasma of patients with HIV-1 infection suggested that in those with an opportunistic infection, viral replication occurred in activated lymphocytes. Interestingly, there was also significant replication in activated macrophages in those patients with untreated pulmonary tuberculosis. Thus, in addition to lymphocytes, the macrophage cellular pool may serve as an important source of cell-free HIV-1 in patients with opportunistic infections that lead to marked macrophage activation. This novel viral capture technique may allow researchers to address a wide range of important questions regarding virus-host dynamics. PMID:10590100

Lawn, Stephen D.; Roberts, Beverly D.; Griffin, George E.; Folks, Thomas M.; Butera, Salvatore T.

2000-01-01