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1.
Redox Biol ; 75: 103285, 2024 Jul 31.
Article in English | MEDLINE | ID: mdl-39128229

ABSTRACT

The ability of Mycobacterium tuberculosis (Mtb) to tolerate nitric oxide (•NO) and superoxide (O2•-) produced by phagocytes contributes to its success as a human pathogen. Recombination of •NO and O2•- generates peroxynitrite (ONOO-), a potent oxidant produced inside activated macrophages causing lethality in diverse organisms. While the response of Mtb toward •NO and O2•- is well established, how Mtb responds to ONOO- remains unclear. Filling this knowledge gap is important to understand the persistence mechanisms of Mtb during infection. We synthesized a series of compounds that generate both •NO and O2•-, which should combine to produce ONOO-. From this library, we identified CJ067 that permeates Mtb to reliably enhance intracellular ONOO- levels. CJ067-exposed Mtb strains, including multidrug-resistant (MDR) and extensively drug-resistant (XDR) clinical isolates, exhibited dose-dependent, long-lasting oxidative stress and growth inhibition. In contrast, Mycobacterium smegmatis (Msm), a fast-growing, non-pathogenic mycobacterial species, maintained redox balance and growth in response to intracellular ONOO-. RNA-sequencing with Mtb revealed that CJ067 induces antioxidant machinery, sulphur metabolism, metal homeostasis, and a 4Fe-4S cluster repair pathway (suf operon). CJ067 impaired the activity of the 4Fe-4S cluster-containing TCA cycle enzyme, aconitase, and diminished bioenergetics of Mtb. Work with Mtb strains defective in SUF and IscS involved in Fe-S cluster biogenesis pathways showed that both systems cooperatively protect Mtb from intracellular ONOO- in vitro and inducible nitric oxide synthase (iNOS)-dependent growth inhibition during macrophage infection. Thus, Mtb is uniquely sensitive to intracellular ONOO- and targeting Fe-S cluster homeostasis is expected to promote iNOS-dependent host immunity against tuberculosis (TB).

2.
Nat Struct Mol Biol ; 2024 Apr 22.
Article in English | MEDLINE | ID: mdl-38649616

ABSTRACT

Protein SUMOylation provides a principal driving force for cellular stress responses, including DNA-protein crosslink (DPC) repair and arsenic-induced PML body degradation. In this study, using genome-scale screens, we identified the human E3 ligase TOPORS as a key effector of SUMO-dependent DPC resolution. We demonstrate that TOPORS promotes DPC repair by functioning as a SUMO-targeted ubiquitin ligase (STUbL), combining ubiquitin ligase activity through its RING domain with poly-SUMO binding via SUMO-interacting motifs, analogous to the STUbL RNF4. Mechanistically, TOPORS is a SUMO1-selective STUbL that complements RNF4 in generating complex ubiquitin landscapes on SUMOylated targets, including DPCs and PML, stimulating efficient p97/VCP unfoldase recruitment and proteasomal degradation. Combined loss of TOPORS and RNF4 is synthetic lethal even in unstressed cells, involving defective clearance of SUMOylated proteins from chromatin accompanied by cell cycle arrest and apoptosis. Our findings establish TOPORS as a STUbL whose parallel action with RNF4 defines a general mechanistic principle in crucial cellular processes governed by direct SUMO-ubiquitin crosstalk.

3.
Account Res ; : 1-28, 2023 Nov 09.
Article in English | MEDLINE | ID: mdl-37943178

ABSTRACT

Consumer mental health apps (MHAs) collect and generate mental health-related data on their users, which can be leveraged for research and product improvement studies. Such studies are associated with ethical issues that may be difficult for researchers and app developers to assess. To improve ethical study conduct, governance through rules, agreements and customs could be relied upon, but their translation into practice is subject to barriers. This qualitative interview study with 17 researchers and app developers looked into the role and impact of governance standards on consumer MHA studies. Interviewees experienced a significant number of rules, agreements and customs, although not all of the governance standards that can potentially be applicable. Standards did have an impact on the interests of researchers and app developers, app users and society, but this impact was mediated by several barriers related to their conceptualization and implementation. Conceptualization barriers impacted the development of a standard, the inclusion of relevant concepts and the coordination between standards. Implementation barriers concerned the resource cost of understanding a standard, as well as suboptimal enforcement. The framework developed in this study can support more effective efforts to improve the governance of future consumer MHA studies.

5.
Diagnostics (Basel) ; 13(9)2023 May 05.
Article in English | MEDLINE | ID: mdl-37175029

ABSTRACT

Limited studies on candidemia in malignancy in the paediatric population from developing countries show a high incidence, high morbidity and a unique epidemiology as compared to developed nations. Our prospective observational study aimed to explore the prevalence of invasive candidiasis, especially candidemia, in febrile paediatric patients with lymphoreticular malignancy. A sample size of 49 children, with 100 recorded febrile episodes was studied. The relevance of candida colonization and mannan antigen detection as indicators of impending candidemia was evaluated. Genotypic identification of the yeast isolates was followed by sequence analysis using the NCBI-BLAST program, and the generation of the phylogenetic tree using MEGA 6.0 software. We observed a 5% prevalence of candidemia among febrile paediatric patients with lymphoreticular malignancy, predominantly caused by non-albicans candida. Colonization at multiple anatomical sites decreased from day 1 to day 8 of febrile episodes. Significant candida colonization (colonization index ≥0.5) was seen in a larger proportion of candidemia patients on day 1 and day 4 (p < 0.001) displaying a definite association between the two. The receiver operator characteristic (ROC) curve analysis for mannan antigen level revealed a cut-off of ≥104.667 pg/mL, suitable for predicting candidemia with a sensitivity of 100%, specificity of 92% and area under ROC value of 0.958 (95% CI: 0.915-1; p < 0.001). A phylogenetic tree with three population groups, clade 1, 2 and 3, consisting of Candida auris (1), Candida tropicalis (2) and Candida parapsilosis (2), respectively, was generated. The diagnosis of candidemia based on mannan antigen detection gives early results and has high negative predictive values. It can be combined with other biomarkers to increase sensitivity, specificity and positive predictive value.

6.
J Biomed Mater Res A ; 111(8): 1120-1134, 2023 08.
Article in English | MEDLINE | ID: mdl-36606330

ABSTRACT

Core decompression (CD) with mesenchymal stromal cells (MSCs) is an effective therapy for early-stage osteonecrosis of the femoral head (ONFH). Preconditioning of MSCs, using inflammatory mediators, is widely used in immunology and various cell therapies. We developed a three-dimensional printed functionally graded scaffold (FGS), made of ß-TCP and PCL, for cell delivery at a specific location. The present study examined the efficacy of CD treatments with genetically modified (GM) MSCs over-expressing PDGF-BB (PDGF-MSCs) or GM MSCs co-over-expressing IL-4 and PDGF-BB and preconditioned for three days of exposure to lipopolysaccharide and tumor necrosis factor-alpha (IL-4-PDGF-pMSCs) using the FGS for treating steroid-induced ONFH in rabbits. We compared CD without cell-therapy, with IL-4-PDGF-pMSCs alone, and with FGS loaded with PDGF-MSCs or IL-4-PDGF-pMSCs. For the area inside the CD, the bone volume in the CD alone was higher than in both FGS groups. The IL-4-PDGF-pMSCs alone and FGS + PDGF-MSCs reduced the occurrence of empty lacunae and improved osteoclastogenesis. There was no significant difference in angiogenesis among the four groups. The combined effect of GM MSCs or pMSCs and the FGS was not superior to the effect of each alone. To establish an important adjunctive therapy for CD for early ONFH in the future, it is necessary and essential to develop an FGS that delivers biologics appropriately and provides structural and mechanical support.


Subject(s)
Mesenchymal Stem Cells , Osteonecrosis , Animals , Rabbits , Femur Head/pathology , Femur Head/surgery , Becaplermin , Interleukin-4/pharmacology , Bone Regeneration , Mesenchymal Stem Cells/pathology , Adrenal Cortex Hormones/pharmacology , Osteonecrosis/chemically induced , Osteonecrosis/therapy , Osteonecrosis/pathology
7.
Scand J Immunol ; 98(5): e13318, 2023 Nov.
Article in English | MEDLINE | ID: mdl-38441343

ABSTRACT

T cell subsets (CD4 and CD8) play a prominent role in the development of chronic rhinosinusitis with nasal polyposis (CRSwNP). Colonization with Aspergillus flavus is recognized as a trigger for the growth of nasal polyps. The fungal proteins initiate the recruitment of T cells into the nasal mucosa, which contributes to the progression of nasal polyps. The study included 50 cases of CRSwNP and 50 healthy controls. Biopsies were subjected to KOH and culture for mycological investigation. We examined the changes in T helper (CD4+) and T cytotoxic (CD8+) in total T cells (CD3+) and expression of naive (CD45RA) and memory (CD45RO) cell markers in T cell subsets in peripheral blood mononuclear cells (PBMCs) challenged by A. flavus antigens in cases before and after treatment and in healthy controls by flow cytometry. Predominantly, A. flavus (86%) identified in nasal polyp biopsies of patients. An increased percentage of CD3+CD4+ T cells observed after A. flavus stimulation in patients when compared with healthy controls. The expression of CD4+CD45RA+ cells was significantly (P < .05) reduced in patients and increased CD4+CD45RO+ was observed upon stimulation with A. flavus in patients when compared with healthy control. Continuous exposure to inhaled fungal spores may induce aberrant immune responses to A. flavus spores, causing an allergic immunological reaction with high CD4+T cell responses, resulting in an unfavourable outcome. Elevated CD4+CD45RO+ T cells may transform the pathogenic response and highlight the chances of A. flavus reactive T cells involvement in prompting inflammation in CRSwNP.


Subject(s)
Hypersensitivity , Nasal Polyps , Rhinosinusitis , Humans , Aspergillus flavus , Leukocytes, Mononuclear , T-Lymphocyte Subsets , Leukocyte Common Antigens
8.
Antibiotics (Basel) ; 10(8)2021 Aug 07.
Article in English | MEDLINE | ID: mdl-34439004

ABSTRACT

Antimicrobial resistance (AMR) is an emerging public health problem in modern times and the current COVID-19 pandemic has further exaggerated this problem. Due to bacterial co-infection in COVID-19 cases, an irrational consumption of antibiotics has occurred during the pandemic. This study aimed to observe the COVID-19 patients hospitalized from 1 March 2019 to 31 December 2020 and to evaluate the AMR pattern of bacterial agents isolated. This was a single-center study comprising 494 bacterial isolates (blood and urine) that were obtained from patients with SARS-CoV-2 admitted to the ICU and investigated in the Department of Microbiology of a tertiary care hospital in Delhi, India. Out of the total bacterial isolates, 55.46% were gram negative and 44.53% were gram positive pathogens. Of the blood samples processed, the most common isolates were CoNS (Coagulase Negative Staphylococcus) and Staphylococcus aureus. Amongst the urinary isolates, most common pathogens were Escherichia coli and Staphylococcus aureus. A total of 60% MRSA was observed in urine and blood isolates. Up to 40% increase in AMR was observed amongst these isolates obtained during COVID-19 period compared to pre-COVID-19 times. The overuse of antibiotics gave abundant opportunity for the bacterial pathogens to gradually develop mechanisms and to acquire resistance. Since the dynamics of SARS-COV-2 are unpredictable, a compromise on hospital antibiotic policy may ultimately escalate the burden of drug resistant pathogens in hospitals. A shortage of trained staff during COVID-19 pandemic renders it impossible to maintain these records in places where the entire hospital staff is struggling to save lives. This study highlights the extensive rise in the use of antibiotics for respiratory illness due to COVID-19 compared to antibiotic use prior to COVID-19 in ICUs. The regular prescription audit followed by a constant surveillance of hospital infection control practices by the dedicated teams and training of clinicians can improve the quality of medications in the long run and help to fight the menace of AMR.

9.
Microb Cell Fact ; 19(1): 215, 2020 Nov 25.
Article in English | MEDLINE | ID: mdl-33238997

ABSTRACT

BACKGROUND: T helper (Th)17 and regulatory T (Treg) cells with toll-like receptor (TLR)-2 have been acknowledged to play a critical role in chronic rhinosinusitis with nasal polyposis (CRSwNP). However, its pathogenesis has been perplexed by conflicting reports on the role of Th17/Treg cells in patients of distinct ethnicities. We attempted to understand the role of Th responses induced during host defense against Aspergillus flavus. RESULTS: The percentages of Th17 (CD4+CD161+IL23R+) and Treg (CD4+CD25+FoxP3+) cell populations and various cytokine profiles in peripheral blood mononuclear cells (PBMCs) challenged by A. flavus antigens were characterized from 50 CRSwNP cases, before and after treatment, and in 50 healthy controls. TLR-2 expression was analyzed in tissues of cases and controls for disease co-relation. The major pathogen identified in our study was A. flavus by mycological investigations. A marked immune imbalance was noted with elevated Th17 and decreased Tregs in PBMCs of CRSwNP patients after A. flavus stimulation. Comparatively, interleukin (IL)-17 and IL-10 levels were increased, with low transforming growth factor (TGF)-ß levels in A. flavus stimulated PBMC supernatants of patients. The mRNA expression of TLR-2 in polyps of CRSwNP patients indicated significant (p = 0.001) upregulation in comparison to the controls. CONCLUSIONS: Our data highlights the excessive expression of TLR-2 in nasal polyps contributing to the imbalance in Th17/Tregs population in patients. After therapy, recovery of Tregs cells indicates restoration and tissue homeostasis, though high circulating CD4+CD161+ Th17 cells may continue to be a threat to patients predisposed to future recurrences. The constant exposure and tendency of A. flavus to colonize nasal cavities can lead to a Th17 driven airway inflammation. Dysregulated Th17 with TLR-2 promote resistance to treatment and progression to the chronicity of the disease.


Subject(s)
Aspergillosis/immunology , Cytokines/immunology , Nasal Polyps/immunology , T-Lymphocytes, Regulatory/immunology , Th17 Cells/immunology , Toll-Like Receptor 2/immunology , Adolescent , Adult , Aspergillus flavus , Chronic Disease , Female , Gene Expression Regulation , Host-Pathogen Interactions , Humans , Interleukin-10/immunology , Interleukin-17/immunology , Male , Middle Aged , RNA, Messenger/immunology , Rhinitis/immunology , Rhinitis/microbiology , Sinusitis/immunology , Sinusitis/microbiology , Toll-Like Receptor 2/genetics , Young Adult
10.
J Educ Health Promot ; 9: 301, 2020.
Article in English | MEDLINE | ID: mdl-33426105

ABSTRACT

INTRODUCTION: Medical education is tricky to imbibe and difficult to apply. Various teaching-learning (TL) methods have been tried from time to time to enhance the proficiency of students. The aim was to assess the students' perception toward three different TL methods (pedagogy, andragogy, and heutagogy) in medical education. MATERIALS AND METHODS: A comparative experimentalquestionnaire-based study was done on population of second-year MBBS students of SMS Medical College, Jaipur, in October 2019. They were taught topic of anticancer drugs using pedagogy, andragogy, and heutagogy methods. Then, their opinion regarding these methods was collected and evaluated. The reliability of the questionnaire was ascertained by Cronbach's alpha value which turned out to be 0.89. The data collected were analyzed statistically using one-way Analysis of Variance (ANOVA) and Principal Component Analysis (PCA). RESULTS: The results showed that all these methods differ significantly from each other as the P < 0.05 considering 5% as level of significance. PCA revealed that andragogy and heutagogy were found to be most effective in this study. CONCLUSION: Competency-based andragogy and capability-based heutagogy are more effective TL methods than didactic lecture-based pedagogy for MBBS undergraduate students.

11.
J Clin Diagn Res ; 11(3): DC01-DC05, 2017 Mar.
Article in English | MEDLINE | ID: mdl-28511379

ABSTRACT

INTRODUCTION: Atopic Dermatitis (AD) is a recurrent chronic condition associated with microorganism and their interaction with the susceptible host. Malassezia yeast is a known commensal which is thought to provoke the recurrent episodes of symptoms in atopic dermatitis patients. Malassezia immunomodulatory properties along with defective skin barrier in such host, results in disease manifestation. Here, we studied Single Nucleotide Polymorphism (SNP) in IL10 and IFN γ genes of the host and its relation with susceptibility to Malassezia infection. AIM: To isolate Malassezia yeast from AD patients and compare the genetic susceptibility of the host by correlating the cytokine gene polymorphism with the control subjects. MATERIALS AND METHODS: Study was conducted from January 2012 to January 2013. It was a prospective observational study done in Department of Microbiology and Department of Dermatology and Venereology in University College of Medical Sciences and GTB Hospital, Delhi. Sample size comprised of 38 cases each of AD. Skin scrapings were used for fungal culture on Sabouraud Dextrose Agar (SDA) and Modified Dixon Agar (MDA) and isolated were identified as per conventional phenotypic methods. Genomic DNA was extracted from blood samples collected from all study subjects. Cytokine genotyping was carried out by Amplification Refractory Mutations System- Polymerase Chain Reaction (ARMS-PCR) with sequence specific primers. Three SNPs (IL10-1082A/G; IL10-819/592C/T; IFN-γ+874A/T) in two cytokine genes were assessed in all the patients and healthy controls. STATISTICAL ANALYSIS: Chi-Square Test or Fisher's-Exact Test and Bonferroni's correction. RESULTS: In AD group, Malassezia yeasts were cultured in 24 out of 38 samples and thus the identification rate was 63.1 percent as compared to healthy group, 52.6 percent (20/38). Significant difference in allele, or genotype distribution were observed in IL10-819/592C/T and IFN-γ+874A/T gene polymorphism in AD group. CONCLUSION: Higher isolation rate in cases as compared to control group highlights the implication of Malassezia in AD. Association between specific cytokine gene polymorphism and clinical outcome was found to be significant in study group. The result of cytokine gene polymorphism in the present study demonstrated susceptibility of host to Malassezia infection.

12.
J Org Chem ; 79(19): 9413-7, 2014 Oct 03.
Article in English | MEDLINE | ID: mdl-25207805

ABSTRACT

In order to understand the structural aspects of stabilization of hydroquinones and their ability to generate reactive oxygen species (ROS), we designed and synthesized a series of 6-aryl-2,3-dihydro-1,4-benzoquinones. These compounds equilibrate with the corresponding 6-aryl-1,4-dihydroxybenzenes in an organic medium; a linear free energy relationship analysis gave ρ = +2.37, suggesting that this equilibrium was sensitive to electronic effects. The propensity of the compound to enolize appears to determine ROS-generating capability, thus offering scope for tunable ROS generation.

13.
Proc Natl Acad Sci U S A ; 110(33): 13594-9, 2013 Aug 13.
Article in English | MEDLINE | ID: mdl-23904484

ABSTRACT

Infection by pathogenic fungi, such as Candida albicans, begins with adhesion to host cells or implanted medical devices followed by biofilm formation. By high-throughput phenotypic screening of small molecules, we identified compounds that inhibit adhesion of C. albicans to polystyrene. Our lead candidate compound also inhibits binding of C. albicans to cultured human epithelial cells, the yeast-to-hyphal morphological transition, induction of the hyphal-specific HWP1 promoter, biofilm formation on silicone elastomers, and pathogenesis in a nematode infection model as well as alters fungal morphology in a mouse mucosal infection assay. We term this compound filastatin based on its strong inhibition of filamentation, and we use chemical genetic experiments to show that it acts downstream of multiple signaling pathways. These studies show that high-throughput functional assays targeting fungal adhesion can provide chemical probes for study of multiple aspects of fungal pathogenesis.


Subject(s)
Candida albicans/drug effects , Cell Adhesion/drug effects , High-Throughput Screening Assays/methods , Hyphae/drug effects , Morphogenesis/drug effects , Piperazines/pharmacology , Small Molecule Libraries/analysis , Animals , Candida albicans/physiology , Cells, Cultured , Epithelial Cells/metabolism , Humans , Hyphae/growth & development , Mice , Nematoda , Piperazines/chemistry , Polystyrenes/chemistry
14.
Virulence ; 4(1): 67-76, 2013 Jan 01.
Article in English | MEDLINE | ID: mdl-23314569

ABSTRACT

Candida albicans is a major fungal pathogen of humans, causing mucosal infections that are difficult to eliminate and systemic infections that are often lethal primarily due to defects in the host's innate status. Here we demonstrate the utility of Caenorhabditis elegans, a model host to study innate immunity, by exploring the role of reactive oxygen species (ROS) as a critical innate response against C. albicans infections. Much like a human host, the nematode's innate immune response is activated to produce ROS in response to fungal infection. We use the C. albicans cap1 mutant, which is susceptible to ROS, as a tool to dissect this physiological innate immune response and show that cap1 mutants fail to cause disease and death, except in bli-3 mutant worms that are unable to produce ROS because of a defective NADPH oxidase. We further validate the ROS-mediated host defense mechanism in mammalian phagocytes by demonstrating that chemical inhibition of the NADPH oxidase in cultured macrophages enables the otherwise susceptible cap1 mutant to resists ROS-mediated phagolysis. Loss of CAP1 confers minimal attenuation of virulence in a disseminated mouse model, suggesting that CAP1-independent mechanisms contribute to pathogen survival in vivo. Our findings underscore a central theme in the process of infection-the intricate balance between the virulence strategies employed by C. albicans and the host's innate immune system and validates C. elegans as a simple model host to dissect this balance at the molecular level.


Subject(s)
Candida albicans/physiology , Gene Expression Regulation, Fungal , Oxidative Stress , Reactive Oxygen Species/toxicity , Stress, Physiological , Transcription Factor AP-1/metabolism , Animals , Caenorhabditis elegans/immunology , Caenorhabditis elegans/microbiology , Candida albicans/drug effects , Candida albicans/genetics , Candidiasis/immunology , Candidiasis/microbiology , Disease Models, Animal , Female , Immunity, Innate , Mice , Mice, Inbred ICR , Phagocytes/immunology , Phagocytes/microbiology , Virulence
15.
Nepal J Ophthalmol ; 3(2): 188-90, 2011.
Article in English | MEDLINE | ID: mdl-21876582

ABSTRACT

BACKGROUND: Alport Syndrome is an uncommon disease. CASE: We report a case of a young Indian male who presented with the characteristic ocular findings and systemic features of Alport Syndrome. CONCLUSION: Any young patient with a chronic renal disease should have a careful ophthalmologic examination for Alport Syndrome.


Subject(s)
Corneal Diseases/diagnosis , Lens Diseases/diagnosis , Nephritis, Hereditary/diagnosis , Retinal Diseases/diagnosis , Deafness/diagnosis , Humans , Male , Young Adult
16.
AIDS Patient Care STDS ; 23(3): 167-76, 2009 Mar.
Article in English | MEDLINE | ID: mdl-19866534

ABSTRACT

In 2006, the Centers for Disease Control and Prevention (CDC) endorsed routine voluntary HIV testing in health care settings to identify the many HIV-infected but undiagnosed persons. Realizing this goal will require primary care providers including internal medicine physicians to order HIV tests routinely. In particular, urban internal medicine trainees who work in high HIV prevalence settings need to adopt this approach. We therefore examined the practice of routine HIV testing and to identify factors that correlate with offering HIV testing to this group. We conducted a self-administered electronic cross-sectional survey of New York City's (NYC) internal medicine residents on HIV testing-related knowledge, attitudes, and behaviors with 29 close-ended questions. Fifteen of 42 NYC internal medicine residency programs participated in early 2007. Of 1175 residents, 450 (38.3%) responded. Most (63.9%) ordered approximately 10 HIV tests in the past 6 months; 32.6% were aware of the 2006 guidelines; 35.8% utilized a routine testing approach. Respondents aware of current guidelines were more likely to practice routine testing (odds ratio [OR] 3.7, 95% confidence interval [CI]: 2.4-5.6). Two common barriers to testing were procedural: time-consuming consent process (27.1%); difficulty locating consent forms (19.3%). Most (68.4%) respondents indicated that oral consent would facilitate more testing. Most NYC internal medicine residents are not routinely offering HIV tests as advised by the 2006 CDC HIV testing guidelines and continue to test patients according to perceived patient HIV risk. This is likely contributing to their low testing rates. Most identified institutional and policy barriers to routine testing. Efforts should be made to improve dissemination of guidelines and address institutional and policy barriers to allow more people to learn their HIV status.


Subject(s)
AIDS Serodiagnosis , Centers for Disease Control and Prevention, U.S./standards , Health Knowledge, Attitudes, Practice , Internal Medicine , Internship and Residency , Physicians/psychology , Practice Guidelines as Topic , AIDS Serodiagnosis/statistics & numerical data , Adult , Cross-Sectional Studies , Female , Guideline Adherence , HIV Infections/diagnosis , Humans , Male , New York City , Surveys and Questionnaires , United States , Young Adult
17.
Eukaryot Cell ; 8(8): 1218-27, 2009 Aug.
Article in English | MEDLINE | ID: mdl-19502579

ABSTRACT

Treatment of systemic fungal infections is difficult because of the limited number of antimycotic drugs available. Thus, there is an immediate need for simple and innovative systems to assay the contribution of individual genes to fungal pathogenesis. We have developed a pathogenesis assay using Caenorhabditis elegans, an established model host, with Saccharomyces cerevisiae as the invading fungus. We have found that yeast infects nematodes, causing disease and death. Our data indicate that the host produces reactive oxygen species (ROS) in response to fungal infection. Yeast mutants sod1Delta and yap1Delta, which cannot withstand ROS, fail to cause disease, except in bli-3 worms, which carry a mutation in a dual oxidase gene. Chemical inhibition of the NADPH oxidase activity abolishes ROS production in worms exposed to yeast. This pathogenesis assay is useful for conducting systematic, whole-genome screens to identify fungal virulence factors as alternative targets for drug development and exploration of host responses to fungal infections.


Subject(s)
Caenorhabditis elegans Proteins/metabolism , Caenorhabditis elegans/microbiology , Disease Models, Animal , Mycoses/microbiology , Oxidoreductases/metabolism , Saccharomyces cerevisiae Proteins/metabolism , Saccharomyces cerevisiae/pathogenicity , Transcription Factors/metabolism , Animals , Caenorhabditis elegans/enzymology , Caenorhabditis elegans/metabolism , Caenorhabditis elegans Proteins/genetics , Host-Pathogen Interactions , Humans , Mutation , Oxidoreductases/genetics , Reactive Oxygen Species/metabolism , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/metabolism , Saccharomyces cerevisiae Proteins/genetics , Transcription Factors/genetics
18.
AIDS Patient Care STDS ; 22(8): 657-62, 2008 Aug.
Article in English | MEDLINE | ID: mdl-18721054

ABSTRACT

Early diagnosis of HIV infection is important for both individual and public health. This study examined patient acceptability of routine, voluntary HIV testing in a New York City hospital serving East Harlem, a diverse community with an HIV seroprevalence of 2.6%. Consecutive admissions to the general medicine service were screened for enrollment between October 27 and November 22, 2005, and March 13 and May 9, 2006. Participants completed a self-administered printed survey and underwent rapid HIV testing. Of the 420 patients approached, 100 patients participated. The most common reason for declining participation was, "I feel too sick to participate." Participants were more likely to be men (odds ratio [OR] 1.71, 95% confidence interval [CI] 1.05, 2.77) and to be in a younger age group (20-49 years; OR 2.70, 95% CI 1.64, 4.45). Participants who reported one or more HIV risk factors were not more likely to answer "Yes" when responding to the statement, "I have risk factors for HIV" compared to patients who did not report any specific clinical or behavioral HIV risk factors (OR = 1.16, 95% CI 0.38,3.53). In addition, patients who reported one or more specific clinical and/or behavioral HIV risk factors were not more likely to have received prior HIV testing (OR = 1.58, 95% CI 0.58, 4.32). Three individuals were newly diagnosed with HIV/AIDS. Risk-based testing may be inadequate, as patients do not accurately assess risk and do not seek or accept testing based on risk. Routine, voluntary HIV testing is able to identify patients missed in the risk-based model of HIV testing, expanding the opportunities for timely diagnosis and intervention. In order to fully implement the new Centers for Disease Control and Prevention (CDC) recommendations for routine, voluntary testing, the optimal timing to offer HIV testing to acutely ill inpatients warrants further investigation.


Subject(s)
AIDS Serodiagnosis , HIV Infections/diagnosis , Patient Acceptance of Health Care , Adult , Aged , Aged, 80 and over , Female , Hospitalization , Hospitals, Urban , Humans , Male , Middle Aged , New York City , Time Factors , Young Adult
19.
Clin Infect Dis ; 36(8): 1030-8, 2003 Apr 15.
Article in English | MEDLINE | ID: mdl-12684916

ABSTRACT

We conducted a retrospective chart review of human immunodeficiency virus (HIV)-infected patients who died in 1995 and in 1999-2000. We found an increase in the proportion of patients who died from an illness that was not related to acquired immunodeficiency syndrome (AIDS). Although there was a decrease in the prevalence of AIDS-defining illnesses, >85% of patients died with CD4 counts of <200 cells/microL. The leading cause of death was Pneumocystis carinii pneumonia (PCP). Nonadherence to therapy and new diagnosis of HIV infection were the leading reasons why patients were not receiving antiretroviral therapy. The leading causes of non-AIDS-related deaths in 1999-2000 were non-AIDS-defining infections and end-stage liver disease. At our hospital, PCP remains an important cause of death in the highly active antiretroviral therapy (HAART) era, possibly because >50% of HIV-infected patients who died were not receiving HAART. AIDS-defining illnesses continue to be a major cause of mortality in the HAART era in populations where access to care and adherence to HAART is limited.


Subject(s)
HIV Infections/mortality , Adult , Aged , Antiretroviral Therapy, Highly Active , Female , HIV Infections/drug therapy , Humans , Male , Middle Aged , Mortality , Retrospective Studies , Survival Analysis
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