43 results on '"E. Tuma"'
Search Results
2. Neurological consultations and diagnoses in a large, dedicated COVID-19 university hospital
- Author
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Adalberto STUDART-NETO, Bruno Fukelmann GUEDES, Raphael de Luca e TUMA, Antonio Edvan CAMELO FILHO, Gabriel Taricani KUBOTA, Bruno Diógenes IEPSEN, Gabriela Pantaleão MOREIRA, Júlia Chartouni RODRIGUES, Maíra Medeiros Honorato FERRARI, Rafael Bernhart CARRA, Raphael Ribeiro SPERA, Mariana Hiromi Manoel OKU, Sara TERRIM, Cesar Castello Branco LOPES, Carlos Eduardo Borges PASSOS NETO, Matheus Dalben FIORENTINO, Julia Carvalhinho Carlos DE SOUZA, José Pedro Soares BAIMA, Tomás Fraga Ferreira DA SILVA, Cristiane Araujo Martins MORENO, Andre Macedo Serafim SILVA, Carlos Otto HEISE, Rodrigo Holanda MENDONÇA, Ida FORTINI, Jerusa SMID, Tarso ADONI, Marcia Rubia Rodrigues GONÇALVES, Samira Luisa Apóstolos PEREIRA, Lecio Figueira PINTO, Helio Rodrigues GOMES, Edmar ZANOTELI, Sonia Maria Dozzi BRUCKI, Adriana Bastos CONFORTO, Luiz Henrique Martins CASTRO, and Ricardo NITRINI
- Subjects
Coronavirus Infections ,COVID-19 ,Neurology ,Seizures ,Stroke ,Metabolic Encephalopathy ,Neuromuscular Diseases ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
ABSTRACT Background: More than one-third of COVID-19 patients present neurological symptoms ranging from anosmia to stroke and encephalopathy. Furthermore, pre-existing neurological conditions may require special treatment and may be associated with worse outcomes. Notwithstanding, the role of neurologists in COVID-19 is probably underrecognized. Objective: The aim of this study was to report the reasons for requesting neurological consultations by internists and intensivists in a COVID-19-dedicated hospital. Methods: This retrospective study was carried out at Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Brazil, a 900-bed COVID-19 dedicated center (including 300 intensive care unit beds). COVID-19 diagnosis was confirmed by SARS-CoV-2-RT-PCR in nasal swabs. All inpatient neurology consultations between March 23rd and May 23rd, 2020 were analyzed. Neurologists performed the neurological exam, assessed all available data to diagnose the neurological condition, and requested additional tests deemed necessary. Difficult diagnoses were established in consensus meetings. After diagnosis, neurologists were involved in the treatment. Results: Neurological consultations were requested for 89 out of 1,208 (7.4%) inpatient COVID admissions during that period. Main neurological diagnoses included: encephalopathy (44.4%), stroke (16.7%), previous neurological diseases (9.0%), seizures (9.0%), neuromuscular disorders (5.6%), other acute brain lesions (3.4%), and other mild nonspecific symptoms (11.2%). Conclusions: Most neurological consultations in a COVID-19-dedicated hospital were requested for severe conditions that could have an impact on the outcome. First-line doctors should be able to recognize neurological symptoms; neurologists are important members of the medical team in COVID-19 hospital care.
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- 2020
- Full Text
- View/download PDF
3. 1232 Case Study "Forging a Better Future": A Ground-Breaking Student-Led EDI Curriculum at the University of Oxford
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de Luca e Tuma, R, primary and Ali, S, additional
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- 2023
- Full Text
- View/download PDF
4. Chip Level Thermal Performance Measurements in Two-Phase Immersion Cooling
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Jimil M. Shah, Thomas Crandall, and Phillip E. Tuma
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Mechanics of Materials ,Electrical and Electronic Engineering ,Computer Science Applications ,Electronic, Optical and Magnetic Materials - Abstract
Two-phase immersion cooling (2PIC) has been proposed as a means of economically increasing overall energy efficiency while accommodating increased chip powers and system-level power density. Designers unfamiliar with Two-phase immersion technology may be unaware of the chip-level thermal performance capabilities of the technology. This performance, in the case of a lidded processor, is quantified as a case-to-fluid thermal resistance, Rcf. This work made use of boiler assemblies comprised of copper plates to which two porous metallic boiling enhancement coatings (BECs) had been applied. These boiler assemblies were applied with conventional thermal grease to a thermal test vehicle (TTV) emulating the Skylake series of 8th Gen Intel® Xeon® CPUs and a thermal test slug (TTS) emulating the Advanced Micro Devices, Inc. (AMD) EPYCTM processors. Both were tested in saturated 3MTM FluorinertTM FC-3284 fluid. The lowest Rcf = 0.020 °C/W was achieved on the TTS at 350 W. The paper also includes additional TTS data gathered with different boiler assemblies and Thermal Interface Materials as well as field data in the form of Rcf or junction-to-fluid thermal resistances, Rjf, for different live silicon chips.
- Published
- 2023
5. Neurological consultations and diagnoses in a large, dedicated COVID-19 university hospital
- Author
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Ricardo Nitrini, Jerusa Smid, Matheus Dalben Fiorentino, Maíra Medeiros Honorato Ferrari, Tarso Adoni, Mariana Hiromi Manoel Oku, Luiz Henrique Martins Castro, Carlos Otto Heise, Gabriela Pantaleão Moreira, Sonia Maria Dozzi Brucki, Márcia Rúbia Rodrigues Gonçalves, Raphael Ribeiro Spera, Rodrigo de Holanda Mendonça, Adalberto Studart-Neto, Júlia Chartouni Rodrigues, Rafael Bernhart Carra, André Macedo Serafim da Silva, Tomás Fraga Ferreira Da Silva, Cesar Castello Branco Lopes, Raphael de Luca e Tuma, Bruno Diógenes Iepsen, Edmar Zanoteli, Antonio Edvan Camelo Filho, Cristiane de Araújo Martins Moreno, Sara Terrim, Carlos Eduardo Borges Passos Neto, Julia Carvalhinho Carlos De Souza, Bruno Fukelmann Guedes, Lécio Figueira Pinto, José Pedro Soares Baima, Ida Fortini, Samira Luisa dos Apostolos Pereira, Gabriel Taricani Kubota, Adriana Bastos Conforto, and Hélio Rodrigues Gomes
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medicine.medical_specialty ,Neurology ,Encephalopathy ,Pneumonia, Viral ,MEDLINE ,Anosmia ,Neurosciences. Biological psychiatry. Neuropsychiatry ,law.invention ,Hospitals, University ,Betacoronavirus ,law ,Seizures ,medicine ,Humans ,Medical diagnosis ,Stroke ,Pandemics ,Referral and Consultation ,Retrospective Studies ,business.industry ,SARS-CoV-2 ,COVID-19 ,Retrospective cohort study ,Metabolic Encephalopathy ,Neuromuscular Diseases ,medicine.disease ,Intensive care unit ,Hospital Bed Capacity ,Emergency medicine ,Neurology (clinical) ,medicine.symptom ,Nervous System Diseases ,business ,Coronavirus Infections ,Brazil ,RC321-571 - Abstract
Background: More than one-third of COVID-19 patients present neurological symptoms ranging from anosmia to stroke and encephalopathy. Furthermore, pre-existing neurological conditions may require special treatment and may be associated with worse outcomes. Notwithstanding, the role of neurologists in COVID-19 is probably underrecognized. Objective: The aim of this study was to report the reasons for requesting neurological consultations by internists and intensivists in a COVID-19-dedicated hospital. Methods: This retrospective study was carried out at Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Brazil, a 900-bed COVID-19 dedicated center (including 300 intensive care unit beds). COVID-19 diagnosis was confirmed by SARS-CoV-2-RT-PCR in nasal swabs. All inpatient neurology consultations between March 23rd and May 23rd, 2020 were analyzed. Neurologists performed the neurological exam, assessed all available data to diagnose the neurological condition, and requested additional tests deemed necessary. Difficult diagnoses were established in consensus meetings. After diagnosis, neurologists were involved in the treatment. Results: Neurological consultations were requested for 89 out of 1,208 (7.4%) inpatient COVID admissions during that period. Main neurological diagnoses included: encephalopathy (44.4%), stroke (16.7%), previous neurological diseases (9.0%), seizures (9.0%), neuromuscular disorders (5.6%), other acute brain lesions (3.4%), and other mild nonspecific symptoms (11.2%). Conclusions: Most neurological consultations in a COVID-19-dedicated hospital were requested for severe conditions that could have an impact on the outcome. First-line doctors should be able to recognize neurological symptoms; neurologists are important members of the medical team in COVID-19 hospital care.
- Published
- 2020
6. The Southeastern U.S. as a complex of use sites for nonbreeding rufa Red Knots: fifteen years of band-encounter data
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Molly E. Tuma and Abby N. Powell
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Animal Science and Zoology ,Aquatic Science ,Ecology, Evolution, Behavior and Systematics - Published
- 2021
7. Clinical, cerebrospinal fluid, and neuroimaging findings in COVID-19 encephalopathy: a case series
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Iago N. Perissinotti, Jerusa Smid, Carlos Benatti Neto, Ida Fortini, Mariana Hiromi Manoel Oku, Bruno Fukelmann Guedes, Adalberto Studart-Neto, Ricardo Nitrini, Gabriel Taricani Kubota, Matheus Dalben Fiorentino, Tarso Adoni, Cesar Castello Branco Lopes, Luiz Henrique Martins Castro, Tomás Silva, Sara Terrim, Antonio Edvan Camelo-Filho, Maíra Medeiros Honorato Ferrari, Rafael Bernhart Carra, Julia Carvalhinho Carlos De Souza, José Pedro Soares Baima, Raphael de Luca e Tuma, Júlia Chartouni Rodrigues, Hélio Rodrigues Gomes, Bruno Diógenes Iepsen, Leandro Tavares Lucato, María M. Martín, and Márcia Rúbia Rodrigues Gonçalves
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Adult ,Male ,medicine.medical_specialty ,Neurology ,Coronavirus disease 2019 (COVID-19) ,medicine.medical_treatment ,CNS demyelination ,Encephalopathy ,Clinical Neurology ,Dermatology ,Severity of Illness Index ,Gastroenterology ,Tertiary Care Centers ,03 medical and health sciences ,0302 clinical medicine ,Cerebrospinal fluid ,Neuroimaging ,Internal medicine ,Severity of illness ,medicine ,Humans ,In patient ,030212 general & internal medicine ,Hospital Mortality ,Dialysis ,Neuroradiology ,Aged ,Retrospective Studies ,Aged, 80 and over ,Mechanical ventilation ,Brain Diseases ,business.industry ,COVID-19 ,Retrospective cohort study ,General Medicine ,Middle Aged ,medicine.disease ,Magnetic Resonance Imaging ,Critical care ,Psychiatry and Mental health ,Female ,Neurology (clinical) ,Neurosurgery ,business ,030217 neurology & neurosurgery - Abstract
ObjectiveTo describe the clinical, neurological, neuroimaging and cerebrospinal fluid (CSF) findings associated with encephalopathy in patients admitted to a COVID-19 tertiary reference center.MethodsWe retrospectively reviewed records of consecutive patients with COVID-19 evaluated by a consulting neurology team from March 30, 2020 through May 15, 2020.ResultsFifty-five patients with confirmed SARS-CoV-2 were included, 43 of whom showed encephalopathy, and were further divided into mild, moderate and severe encephalopathy groups. Nineteen patients (44%) had undergone mechanical ventilation and received intravenous sedatives. Eleven (26%) patients were on dialysis. Laboratory markers of COVID-19 severity were very common in encephalopathy patients, but did not correlate with the severity of encephalopathy. Thirty-nine patients underwent neuroimaging studies, which showed mostly non-specific changes. One patient showed lesions possibly related to CNS demyelination. Four had suffered an acute stroke. SARS-CoV-2 was detected by RT-PCR in only one of 21 CSF samples. Two CSF samples showed elevated white blood cell count and all were negative for oligoclonal bands. In our case series the severity of encephalopathy correlated with higher probability of death during hospitalization (OR = 5.5 for each increment in the degree of encephalopathy, from absent (0) to mild (1), moderate (2) or severe (3), pConclusionIn our consecutive series with 43 encephalopathy cases, neuroimaging and CSF analysis did not support the role of direct viral CNS invasion or CNS inflammation as the cause of encephalopathy.
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- 2021
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8. Different patterns of β‐amyloid pathology in the cerebellum of early‐onset Alzheimer’s disease individuals
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Ricardo Nitrini, Roberta Diehl Rodriguez, Carlos Augusto Pasquallucci, Renata Elaine Paraizo Leite, Lea T. Grinberg, Claudia K. Suemoto, Sonia Maria Dozzi Brucki, Wilson Jacob-Filho, Raphael de Luca e Tuma, and Renata Eloah de Lucena Ferretti-Rebustini
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Cerebellum ,Pathology ,medicine.medical_specialty ,Amyloid ,Epidemiology ,business.industry ,Health Policy ,Neuropathology ,medicine.disease ,Psychiatry and Mental health ,Cellular and Molecular Neuroscience ,medicine.anatomical_structure ,Developmental Neuroscience ,β amyloid ,medicine ,Early-onset Alzheimer's disease ,Neurology (clinical) ,Geriatrics and Gerontology ,business - Published
- 2020
9. Immersion Cooled ARM-Based Computer Clusters towards Low-Cost High-Performance Computing
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Philip E. Tuma, Huseyin Bostanci, and Mohammed Awaizulla Shareef
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Natural convection ,Computer science ,02 engineering and technology ,Integrated circuit ,Energy consumption ,Supercomputer ,020202 computer hardware & architecture ,law.invention ,Forced convection ,law ,Computer cluster ,0202 electrical engineering, electronic engineering, information engineering ,020201 artificial intelligence & image processing ,Junction temperature ,Simulation ,Efficient energy use - Abstract
This study aimed to investigate performance of ARM-based computer clusters using two-phase immersion cooling (IC) approach, and demonstrate its potential benefits over the air-based natural convection (NC) and forced convection (FC) approaches. ARM-based clusters were created using Raspberry Pi (Rpi) model 2 and 3, a commodity-level, single-board computer. The IC mode utilized two types of dielectric liquids, HFE-7100 and HFE-7000. Experiments involved running benchmarking programs Sysbench, and the combination of Sysbench and High-Performance Linpack (HPL), in order to quantify the key parameters of device junction temperature, operating frequency, execution time, computing performance, and energy consumption. Results indicated that the device junction temperature has direct effects on the computing performance and energy consumption. In the reference NC cooling mode, as the temperature approached the preset limit, the Rpi-3 cluster either decreased its operating frequency to save the internal cores from damage, leading to decrease in computing performance and increase in execution time and energy consumption (in the Sysbench test), or shut down all the nodes (in the HPL test). When the Rpi-3 cluster was exposed to a heavy load (combined Sysbench and HPL test) the IC modes compared to the FC mode indicated similar execution time, up to 3% higher computing performance, and up to 10% lower energy consumption. Although the results for the considered Rpi clusters do not represent a significant improvement, this study demonstrates that the two-phase IC method with its near-isothermal, high heat transfer capability would enable fast, energy efficient and reliable operation, particularly benefiting high performance and large scale computing applications where conventional air-based cooling methods would fail.
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- 2020
10. The Effect of Leptin Level in Pregnancy Complicated by Intrauterine Growth Restriction on Neonatal Outcome, in an Iraqi Center
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Taghreed K. i ALhaidar, Wafa E. Tuma, and Treeva Khdhair Jassim,
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Intrauterine growth restriction ,cord blood leptin ,maternal serum leptin ,Medicine - Abstract
Background: Fifteen percent of small for gestational age are small as a result of fetal growth restriction, which could be due to maternal, placental or fetal factors. It is an important clinical problem associated with increase perinatal mortality and morbidity. Leptin is a protein that produced by many tissues including the placenta (syncytiotropholoast). Dysregulation of leptin metabolism may be implicated in preeclampsia and IUGR pathogenesis. Aim of the study: To study the trend of leptin level alteration in maternal serum and cord blood in pregnancies complicated by fetal growth restriction and its relation with fetal outcome. Methods: An Analytic, cross- sectional study conducted in Al-Elwyia Maternity Teaching Hospital and Alkindy College of Medicine, from October 2009 to June 2010. Sixty seven pregnant women were included and they were divided into two groups: The first group (A) included 34 pregnant women with Intrauterine growth restricted fetuses with and without maternal diseases and the second group (B), included 33 pregnant women with normal pregnancies. Samples from maternal blood and umbilical cord blood were obtained at the time of delivery and leptin level was measured by Enzyme linked immunesorbant assey (ELISA) test. Results:Umbilical cord leptin level was significantly lower in group A (medain1ng/ml) compared with group B (median10.2ng/ml); P
- Published
- 2012
11. Metabolic syndrome in women with polycystic ovary syndrome
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Khalid Ibrahim Al - Lehibi, Wafaa E. Tuma, and Khalida J. Ibrahim(
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Polycystic ovary syndrome (PCOS) ,metabolic syndrome(MBS) ,Fasting plasma glucose (FPG) ,Medicine - Abstract
Background: Polycystic ovary syndrome (PCOS) is the most common form of chronic anovulation associated with androgen excess; it occurs in about 5 – 10% 0f reproductive age women. Metabolic syndrome is characterized by insulin resistance, hypertension, obesity, abnormalities of blood clotting and dyslipidemia. Adult women with PCOS have an increased prevalence of the metabolic syndrome(MBS). Objectives: To detect the prevalence of metabolic syndrome in women with proved PCOS, attending the Specialized Center for Endocrinology and Diabetes, in Baghdad. Materials and methods : A total number of 40 women with proved PCOS were included in this study which was conducted in the Specialized Center for Endocrinology and Diabetes-Baghdad, over a period of 5 months(from April till September 2005).In addition to measuring waist circumference and body mass index(BMI),all patients were tested for the levels of C-peptide, Fasting plasma glucose(FPG), Serum luteinizing hormone(LH), Follicle st – imulating hormone(FSH), Prolactin(PRL), Progesterone, estradiol(E2), testosterone,T3,T4 and TSH . Also lipid profile, glycated hemoglobin(HbA1c) were estimated to all patients. Glucose tolerance test(GTT) using 75 gm of glucose was performed on all patients. Results: Out of 40 women with PCOS,eleven patients(27.5%) have impaired GTT. Twenty patients (50%) out of 40 fulfil the criteria of the International Diabetes Fideration(IDF) Consensus Definition of the metabolic syndrome(MBS)-2005. Thirty-Seven patients(92.5%) have a waist circumference more than 80 cm. Thirty-two patients(80%) have secondary amenorrhea. Hirsuitism and increased BMI(body mass index) were present in 33 patients(82.5%) The mean C-peptide level was higher in those patients who had impaired GTT(11 patients),meaning that GTT can be used to detect insulin resistance specially in Labs. where measurements of insulin levels are not available. Conclusions : 1. Metabolic syndrome is present in 50% of our patients,using the IDF Consensus Definition of the metabolic syndrome-2005. 2. Glucose tolerance test can be used to detect the presence of insulin resistance specially in Labs. where measurements of insulin levels are not available. 3. Insulin resistance is present in 27.5% in women with PCOS who were included in our study.
- Published
- 2011
12. Different patterns of β‐amyloid pathology in the cerebellum of early‐onset Alzheimer’s disease individuals
- Author
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de Luca e Tuma, Raphael, primary, Rodriguez, Roberta Diehl, additional, Brucki, Sonia Maria Dozzi, additional, Suemoto, Claudia Kimie, additional, Leite, Renata Elaine Paraizo, additional, Ferretti‐Rebustini, Renata Eloah de Lucena, additional, Jacob‐Filho, Wilson, additional, Pasquallucci, Carlos Augusto, additional, Grinberg, Lea Tenenholz, additional, and Nitrini, Ricardo, additional
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- 2020
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13. Indwelling urethral versus suprapubic catheters in nursing home residents: determining the safest option for long-term use
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Lona Mody, Jennifer Meddings, S. Neill, E. Tuma, and Kristen Gibson
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Microbiology (medical) ,Male ,medicine.medical_specialty ,Urinary system ,Indwelling Device ,Urethral Catheters ,030501 epidemiology ,Article ,Catheterization ,03 medical and health sciences ,Catheters, Indwelling ,Medicine ,Infection control ,Humans ,Aged ,Aged, 80 and over ,0303 health sciences ,030306 microbiology ,business.industry ,Incidence (epidemiology) ,Incidence ,Hazard ratio ,General Medicine ,Bacterial Infections ,Middle Aged ,Nursing Homes ,Catheter ,Infectious Diseases ,Catheter-Related Infections ,Emergency medicine ,Urinary Tract Infections ,Female ,0305 other medical science ,Nursing homes ,business - Abstract
The incidence of infectious complications has not been previously compared for two types of common urinary catheters used in the long-term care setting: indwelling urethral catheters and suprapubic catheters.To compare catheter-associated urinary tract infection (CAUTI) rates and multidrug-resistant organism (MDRO) colonization between nursing home residents with indwelling urethral and suprapubic catheters.Participants included 418 nursing home residents with an indwelling device enrolled in a previously published prospective targeted infection prevention study conducted between 2010 and 2013. Resident age, gender, function, comorbidities, and information on infections, antibiotic use, and recent hospitalizations were obtained at study enrolment, day 14, and every 30 days thereafter for up to one year. Microbiological samples were obtained from several anatomic sites at each visit. Cox proportional hazard models were adjusted for facility-level clustering and other covariates.In all, 208 study participants had an indwelling urinary catheter, contributing 21,700 device-days; 173 (83%) with a urethral catheter, 35 (17%) with a suprapubic catheter. After covariate adjustment, the suprapubic group had a lower incidence of CAUTI (6.6 vs 8.8 per 1000 device-days; P = 0.05), were half as likely to be hospitalized (hazard ratio (HR) = 0.46; P0.01) and were 23% less likely to have had antibiotics in the past 30 days (HR = 0.77; P = 0.02). Among residents catheterized ≥90 days, the mean number of MDROs isolated in the suprapubic group was significantly higher than in the urethral group (0.57 vs 0.44; P = 0.01). Ciprofloxacin-resistant Gram-negative bacilli were frequent in both groups.Residents with a suprapubic catheter may have fewer CAUTIs, less hospitalization and less antibiotic use, but are more likely colonized with MDROs.
- Published
- 2018
14. Neurological consultations and diagnoses in a large, dedicated COVID-19 university hospital.
- Author
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STUDART-NETO, Adalberto, GUEDES, Bruno Fukelmann, de Luca e TUMA, Raphael, CAMELO FILHO, Antonio Edvan, KUBOTA, Gabriel Taricani, IEPSEN, Bruno Diógenes, MOREIRA, Gabriela Pantaleão, RODRIGUES, Júlia Chartouni, FERRARI, Maíra Medeiros Honorato, CARRA, Rafael Bernhart, SPERA, Raphael Ribeiro, OKU, Mariana Hiromi Manoel, TERRIM, Sara, LOPES, Cesar Castello Branco, PASSOS NETO, Carlos Eduardo Borges, FIORENTINO, Matheus Dalben, DE SOUZA, Julia Carvalhinho Carlos, BAIMA, José Pedro Soares, DA SILVA, Tomás Fraga Ferreira, and MORENO, Cristiane Araujo Martins
- Abstract
Copyright of Arquivos de Neuro-Psiquiatria is the property of Thieme Medical Publishing Inc. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2020
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15. CHAOTIC BEHAVIOR OF ORBITS CLOSE TO A HETEROCLINIC CONTOUR
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M. Blázquez and E. Tuma
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Equilibrium point ,Discrete mathematics ,Applied Mathematics ,Modeling and Simulation ,Mathematical analysis ,Chaotic ,Heteroclinic cycle ,Type (model theory) ,Heteroclinic bifurcation ,Engineering (miscellaneous) ,Mathematics - Abstract
We study the behavior of the solutions in a neighborhood of a closed contour formed by two heteroclinic connections to two equilibrium points of saddle-focus type. We consider both the three-dimensional case, as in the well-known Chua's circuit, as well as the infinite-dimensional case.
- Published
- 1996
16. STRANGE ATTRACTORS OF THE SHIL'NIKOV TYPE IN CHUA'S CIRCUIT
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M. Blázquez and E. Tuma
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Chua's circuit ,Equilibrium point ,Mathematics::Dynamical Systems ,Applied Mathematics ,Mathematical analysis ,Chaotic ,Heteroclinic cycle ,Type (model theory) ,Nonlinear Sciences::Chaotic Dynamics ,Modeling and Simulation ,Attractor ,Heteroclinic orbit ,Homoclinic orbit ,Engineering (miscellaneous) ,Mathematics - Abstract
The chaotic behavior of the solutions of Chua's circuit is studied in the neighborhood of a homoclinic orbit to an equilibrium point of the saddle-focus type and in a neighborhood of two heteroclinic orbits to saddle-focus points which form a closed contour.
- Published
- 1993
17. Chaos in infinite dimensions: a generalization of a theorem of Sil'nikov
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E. Tuma and M. Blázquez
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Pure mathematics ,Fundamental theorem ,Generalization ,Differential equation ,Applied Mathematics ,No-go theorem ,Mathematical analysis ,Banach space ,Existence theorem ,Infinite product ,Homoclinic orbit ,Analysis ,Mathematics - Published
- 1993
18. DYNAMICS OF CHUA'S CIRCUIT IN A BANACH SPACE
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E. Tuma and C. M. Blázquez
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Chua's circuit ,Mathematical analysis ,Banach space ,General Medicine ,Banach manifold ,Type (model theory) ,Nonlinear Sciences::Chaotic Dynamics ,Dimension (vector space) ,Hardware and Architecture ,Point (geometry) ,Homoclinic orbit ,Electrical and Electronic Engineering ,C0-semigroup ,Mathematics - Abstract
In this paper we present generalized theorems of the Shil'nikov type for evolution equations in Banach spaces of infinite dimension, which describe the behaviour of subsystems of solutions in a neighborhood of a double homoclinic orbits to the same saddle-focus point.
- Published
- 1993
19. The stability of solutions in an initial-boundary reaction-diffusion system
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C.M. Blázquez and E. Tuma
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General Mathematics ,Reaction–diffusion system ,Boundary (topology) ,Geometry ,Stability (probability) ,Boundary values ,Mathematics ,Mathematical physics - Abstract
We study the asymptotic behaviour as t → ∞ of solutions of the initial-boundary value problem vt = G(u, v), ut = uxx + F(u, v), and t > 0, x ∈ ℝ or x ∈ ℝ+ for a wide class of initial and boundary values, where F and G are smooth functions so that the system has three rest points.
- Published
- 1992
20. THE STABILITY OF TRAVELLING-WAVE-FRONT SOLUTIONS IN AN INITIAL-BOUNDARY REACTION-DIFFUSION SYSTEM
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E. Tuma and C. M. Blazquez
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Classical mechanics ,Mechanics of Materials ,Applied Mathematics ,Mechanical Engineering ,Reaction–diffusion system ,Front (oceanography) ,Traveling wave ,Boundary (topology) ,Mechanics ,Condensed Matter Physics ,Stability (probability) ,Mathematics - Published
- 1992
21. Practical considerations relating to immersion cooling of power electronics in traction systems
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Cindy M. Barnes and Phillip E. Tuma
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Engineering ,Leak ,business.product_category ,business.industry ,Nuclear engineering ,Electrical engineering ,Electronic packaging ,Insulated-gate bipolar transistor ,chemistry.chemical_compound ,Hydrofluoroether ,Heat flux ,chemistry ,Air conditioning ,Power electronics ,Heat transfer ,Thermal ,Water cooling ,Die (manufacturing) ,Power semiconductor device ,Electrical and Electronic Engineering ,business - Abstract
Junction-to-fluid thermal resistivities, R″ jf , of two dual-side-soldered Insulated Gate Bipolar Transistor (IGBT) modules immersion-cooled in a hydrofluoroether C 3 F 7 OCH 3 liquid were measured experimentally. R″ jf =0.040°C-cm2/W for 0.144 cm2 die at a peak heat flux of 1180 W/cm2 and 55 Amps and 0.11°C-cm2/W for 1.46 cm2 die at a peak heat flux of 550 W/cm2 and 305 Amps. A technique for automatic in situ degassing that would reduce manufacturing cost and permit field servicing of immersion systems that reach sub-ambient pressure when idle showed fluid loss rates of 0.3g per 100cc of air vented, roughly 1/100th that expected from an HFC-134a air conditioning system with a similar leak. Experiments to quantify packaging density and fluid requirements suggest that 100cc of fluid is required to dissipate 1kW and packaging density is limited only by the electrical bus geometry.
- Published
- 2009
22. Dynamics of the double scroll circuit
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C.M. Blazquez and E. Tuma
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Nonlinear Sciences::Chaotic Dynamics ,Mathematics::Dynamical Systems ,System of differential equations ,Mathematical analysis ,Dynamics (mechanics) ,General Engineering ,Scroll ,Homoclinic bifurcation ,Point (geometry) ,Homoclinic orbit ,Nonlinear differential equations ,Network analysis ,Mathematics - Abstract
Consideration is given to a system of differential equations which has two homoclinic solutions to a same saddle-focus point. The authors prove the existence of a subsystem of solutions which remain in a neighborhood of those homoclinic orbits. In addition to the upper and lower subsystem already described by L. Slinikov's (1965) theorem, this theorem contains solutions that switch in every turn from the neighborhood of one homoclinic to the neighborhood of the other. >
- Published
- 1990
23. [Identification of CD11c+ myeloid dentritic cells in adenoids and in nasal mucosa of patients with and without allergies]
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E, Tuma, S, Rothenfusser, G, Hartmann, and B, Wollenberg
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Nasal Mucosa ,Rhinitis, Allergic, Perennial ,CD11 Antigens ,Child, Preschool ,Data Interpretation, Statistical ,Adenoids ,Humans ,Rhinitis, Allergic, Seasonal ,Dendritic Cells ,Child ,Flow Cytometry - Abstract
Dendritic cells form a link between innate and acquired immunity. They are capable to detect pathogens based on the recognition of pathogen-associated microbial molecules and trigger the appropriate type of immune responses. In humans, three major subsets of dendritic cells can be distinguished, Langerhans cells of the skin, myeloid DC (MDC) and plasmacytoid DC (PDC). It was reported that PDC infiltrate nasal mucosa in allergen-induced rhinitis. Information about the role of MDC in nasal mucosa and the corresponding mucosa-associated lymphoid tissue, the nasopharyngeal adenoids, is limited.: Here we examined the presence of MDC in adenoids and in nasal mucosa of healthy individuals (n = 9) and in patients with allergic rhinitis. MDC were detected by flow cytometry by positive staining for MHC II and CD11c and the lack of lineage markers. Dead cells were excluded from analysis.In adenoids, 0.4 % of all cells were MDC. Considerable numbers of MDC could also be detected in nasal mucosa. No difference was found between healthy individuals and patients with allergies (0.3 % vs. 0.45 % MDC; p = 0.12). Interestingly, MDC were absent in patients who received treatment with glucocorticoids, while very high numbers of MDC were found in patients who recently had upper respiratory tract infections.Our results demonstrate for the first time the presence of MDC in nasal mucosa. MDC numbers were similar in healthy individuals and in patients with allergy. This study forms the basis for examining the role of MDC in the pathogenesis of allergic rhinitis, and for the modulation of MDC functional activity with microbial molecules such as CpG oligonucleotides.
- Published
- 2002
24. DYNAMICS OF CHUA'S CIRCUIT IN A BANACH SPACE
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C. M. BLÁZQUEZ and E. TUMA
- Published
- 1993
25. Announcements / Book Review
- Author
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Frank Schweda, Katherina Vanden Houte, Bahattin Adam, Dirk De Craemer, Rafael Bárcena, Aldo Fabris, F. Amorós, Bedani Pl, M.J. Aguado, Sadayoshi Ito, J. Sáez, Hiroyuki Kimura, G.E. Russo, Isidoro Scirè Risichella, Yoko Ohtsuka, Matteo Rigolin, Jun Soma, G.V. Ramesh Prasad, E. Tuma, Glen H. Murata, Noriaki Yorioka, N. Futrakul, J.B. Cabezuelo, F. Valderrábano, J. García de Bustos, Kenji Nakayama, Kozue Uchio, Akira Ohishi, Takao Saito, M. Bosco, Gülsan Türköz Sucak, E. Paskalev, Yuichi Sugisaki, Noboru Manabe, Tasanee Panichakul, Nobuaki Yamanaka, Jaakko Antonen, S. Aldred, Araki Tanaka, Hans Konrad Biesalski, Hikaru Koide, Gian Luigi Scapoli, Yukinari Masuda, E. Verde, Takashi Kabaya, Yutaka Takahashi, Christiane Van Den Branden, Jian She Liu, Abdulkerim Bedir, Morio Nakamura, Shigehisa Aoki, Yoji Nishida, M. Toepfer, Tarkan Karakan, Takanobu Sakemi, Tohru Iwahori, B. Bauco, Reinhard Schinzel, Jaana Syrjänen, Claudio Gardin, Yoshie Yamamoto, Deepak Malhotra, Carl J. Cardella, Antonios H. Tzamaloukas, R.W. Grunewald, Maria Valentina Pellanda, Noboru Aosaki, K.M. Hummel, Adriano Verzola, Sung Kyew Kang, Kazuyoshi Okada, Inad Halefi, Shiv Kapoor, Marcelo S. Silva, Hiroshi Nihei, Suthiluck Patumraj, A.E. Sirvent, András Mogyorósi, V.R. Nimmagadda, Joaquín Ortuño, M. Bonello, Albert Geerts, Günter A.J. Riegger, August Heidland, Sung Kwang Park, Shigeruko Iijima, F. Fabbian, Hubin Gao, A.S. Reddi, G. Casari, Karine Hellemans, Friedrich C. Blumberg, Kenichi Yahiro, A. De Paola, Yukinari Osaka, E. Ojeda, Susie Q. Lew, Paolo Gilli, Won Gu Kim, E. Vitaliano, R. Pérez-García, Gou Young Koh, Anna-Maija Koivisto, Mitsufumi Mayumi, Yuji Ikeda, Angelika Waidheim, Jürgen Frank, Napoleone Prandini, Misuzu Yamaguchi, Kanako Shimazu, Horacio Ajzen, M. Oellerich, Pieter De Bleser, Masaharu Yoshida, Hafize Uzun, Makoto Miyamoto, S. Patumraj, Andrea Contestabile, Nobuhisa Yonemitsu, Fumio Ito, Fujio Otsuka, Juan P. Bosch, M.G. Bianchetti, P. Futrakul, Isao Kurihara, Kai J.E. Krohn, Masahiro Hiraoka, M. Martínez, G. Colussi, N. von Ahsen, Akira Shimizu, N. Stabellini, Hiroshi Toma, Jin Chang Shao, J.S. Bollineni, Aparecido B. Pereira, Gerald M. Devins, Terho Lehtimäki, E. Quevedo, Norbert Braun, Dierik Verbeelen, Kenneth Taub, A. Sanz, Serdar Turkmen, David J. Hollomby, Keiko Yamada, Osamu Ryoji, Rauf Haznedar, Kosaku Nitta, Emanuela De Vivo, J.J.R. Foster, Isao Ishikawa, Kwang Young Lee, Masamichi Ishizaki, Xiao-Hong Huang, Jukka Mustonen, U. Kaboth, Isao Ebihara, Hiroshi Kitamura, Caroline Nabel, Alessandro Amore, F. Hernandez Navarro, Heikki Saha, S. Endres, Kinichi Hamaguchi, Tetsuya Ootaka, Preedawan Chaisuriya, Susumu Takahashi, Gianna Mastroianni Kirsztajn, J. Uribarri, A. Eigler, H. Schiffl, Timo Koivula, Prasit Futrakul, Rosanna Coppo, S. Baskin, Amos Pasternack, P. Butthep, E.A. Lock, Tsukasa Nakamura, Bart Ceyssens, Hayakazu Nakazawa, E. Rizzioli, Takao Masaki, Bernhard K. Krämer, Amit Kapoor, Kumar Sharma, Dae Yul Lee, Noriaki Shimada, Marina Pauwels, Edward H. Cole, Michio Yamakido, Stitaya Sirisinha, Päivi M. Hannula, A. Bettinelli, María Luisa Mateos, Tomoko Mimuro, Resat Ozaras, Katarína Šebeková, Safiye Dondurmaci, David Tarrago, Veysel Tahan, Yitzchak M. Binik, Nurol Arik, Shingo Suzuki, Tooru Hiragi, Teut Risler, Sonia K. Nishida, Annette Schweda, M.A. Foncillas, Leendert C. Paul, Seval Aydin, D. Fava, Yoko Osaka, Kotaro Tamura, Nemuko Ono, D. Consonni, Hisashi Okuda, Chifuyu Ushiyama, R.-B. Kühn, Akihiro Kondo, Motohide Isono, Satoshi Ogata, H. Baker, Toshiaki Nakajima, Naoko Tomida, Henry Mandin, Joan M. Sweet, A. Reyes, Akira Kawashima, G.A. Müller, C. Catalano, S. Villatico Campbell, M.R. Trapassi, Ana Gonzalo, Hisataka Shoji, R. Enríquez, Yoshiyuki Tomiyoshi, Stephan R. Holmer, Gulsum Emel Oztekin, Atsuo Ogura, Hiroshi Sato, Paul E. Barré, R.H. Waring, Hirokazu Tsukahara, Kimie Narusawa, Musa Bali, P. Gilli, Ronald Guttmann, M.F. Bisciglia, Murat Günaydin, Hajime Miyamoto, Hiroshi Kikuchi, Michael Pfeifer, Fuad N. Ziyadeh, Narisa Futrakul, Maurizio Bergami, Keiko Sekizuka, and Ryuji Ohashi
- Subjects
Gynecology ,medicine.medical_specialty ,business.industry ,Family medicine ,medicine ,business - Published
- 2000
26. Comparison principles for strongly coupled reaction diffusion equations in unbounded domains
- Author
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E. Tuma
- Subjects
Strongly coupled ,Partial differential equation ,General Mathematics ,Mathematical analysis ,Reaction–diffusion system ,Diffusion (business) ,Mathematics - Abstract
SynopsisComparison principles for systems of reaction–diffusion equations in unbounded domains and coupledvia both reaction and diffusion terms are considered. Applications are made to the FitzHugh–Nagumo equations and models of coupled nerve fibres.
- Published
- 1988
27. Comparison principles for strongly coupled reaction-diffusion equations
- Author
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E. Tuma and Brian D. Sleeman
- Subjects
Strongly coupled ,Coupling (physics) ,Partial differential equation ,Invariance principle ,General Mathematics ,Reaction–diffusion system ,Geometry ,Mathematics ,Mathematical physics - Abstract
SynopsisComparison principles for systems of reaction-diffusion equations coupled via both the reaction and diffusion terms are considered. Applications to the FitzHugh–Nagumo equations and models of coupled nerve fibres are included.
- Published
- 1987
28. THE ASYMPTOTIC BEHAVIOUR OF SOLUTIONS OF BELOUSOV-ZHABOTINSKII TYPE REACTION-DIFFUSION EQUATIONS
- Author
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E. Tuma, Peter Grindrod, and Brian D. Sleeman
- Subjects
Computer Science::Emerging Technologies ,Partial differential equation ,Mechanics of Materials ,Applied Mathematics ,Mechanical Engineering ,Reaction–diffusion system ,Thermodynamics ,Type (model theory) ,Nonlinear Sciences::Cellular Automata and Lattice Gases ,Nuclear Experiment ,Condensed Matter Physics ,Nonlinear Sciences::Pattern Formation and Solitons ,Mathematics - Abstract
On etudie le comportement pour t grand des solutions d'une classe d'equations de reaction-diffusion simulant les oscillations entretenues dans les reactions chimiques. On generalise les resultats obtenus pour le modele de reaction de Belousov-Zhabotinski
- Published
- 1986
29. BOUNDS FOR WAVE-FRONT SOLUTIONS TO THE FITZHUGH-NAGUMO EQUATIONS
- Author
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Brian D. Sleeman and E. Tuma
- Subjects
Wavefront ,Physics ,Mechanics of Materials ,Applied Mathematics ,Mechanical Engineering ,Mathematical analysis ,Condensed Matter Physics ,Fitzhugh nagumo - Published
- 1985
30. On Exact Solutions of a Class of Reaction-Diffusion Equations
- Author
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Brian D. Sleeman and E. Tuma
- Subjects
Class (set theory) ,Partial differential equation ,Elliptic partial differential equation ,Applied Mathematics ,Reaction–diffusion system ,Mathematical analysis ,First-order partial differential equation ,Characteristic equation ,Mathematics - Abstract
On developpe une methode basee sur la transformee de Laplace pour determiner des solutions explicites aux problemes de Cauchy pour une grande classe d'equations de reaction-diffusion
- Published
- 1984
31. Hereroclinic bifurcation in banach spaces
- Author
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E. Tuma and M. Blázquez
- Subjects
Physics ,Differential equation ,Saddle point ,Mathematical analysis ,Banach space ,Periodic orbits ,Perturbation (astronomy) ,Homoclinic orbit ,Parabolic partial differential equation ,Bifurcation - Abstract
We study conditions under which a unique periodic orbit is generated from a heteroclinic contour when we add an autonomous perturbation to parabolic equations and to retarded differential equation.
- Published
- 1988
32. Family Socioeconomic Status and Adolescent Attitudes to Authority
- Author
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E, TUMA and N, LIVSON
- Subjects
Adolescent ,Attitude ,Social Class ,Sociology ,Pediatrics, Perinatology and Child Health ,Developmental and Educational Psychology ,Humans ,Education - Published
- 1960
33. Journal update monthly top five.
- Author
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Horner D, Kelly A, Heap J, Stocks C, Tuma E, Clews A, and Kilgour P
- Abstract
Competing Interests: Competing interests: None declared.
- Published
- 2022
- Full Text
- View/download PDF
34. Burkholderia thailandensis Methylated Hydroxyalkylquinolines: Biosynthesis and Antimicrobial Activity in Cocultures.
- Author
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Klaus JR, Majerczyk C, Moon S, Eppler NA, Smith S, Tuma E, Groleau MC, Asfahl KL, Smalley NE, Hayden HS, Piochon M, Ball P, Dandekar AA, Gauthier C, Déziel E, and Chandler JR
- Subjects
- Methylation, Anti-Infective Agents pharmacology, Burkholderia metabolism, Quinolones metabolism
- Abstract
The bacterium Burkholderia thailandensis produces an arsenal of secondary metabolites that have diverse structures and roles in the ecology of this soil-dwelling bacterium. In coculture experiments, B. thailandensis strain E264 secretes an antimicrobial that nearly eliminates another soil bacterium, Bacillus subtilis strain 168. To identify the antimicrobial, we used a transposon mutagenesis approach. This screen identified antimicrobial-defective mutants with insertions in the hmqA , hmqC , and hmqF genes involved in biosynthesis of a family of 2-alkyl-4(1 H )-quinolones called 4-hydroxy-3-methyl-2-alkenylquinolines (HMAQs), which are closely related to the Pseudomonas aeruginosa 4-hydroxy-2-alkylquinolines (HAQs). Insertions also occurred in the previously uncharacterized gene BTH_II1576 (" hmqL "). The results confirm that BTH_II1576 is involved in generating N -oxide derivatives of HMAQs (HMAQ-NOs). Synthetic HMAQ-NO is active against B. subtilis 168, showing ∼50-fold more activity than HMAQ. Both the methyl group and the length of the carbon side chain account for the high activity of HMAQ-NO. The results provide new information on the biosynthesis and activities of HMAQs and reveal new insight into how these molecules might be important for the ecology of B. thailandensis IMPORTANCE The soil bacterium Burkholderia thailandensis produces 2-alkyl-4(1 H )-quinolones that are mostly methylated 4-hydroxyalkenylquinolines, a family of relatively unstudied metabolites similar to molecules also synthesized by Pseudomonas aeruginosa Several of the methylated 4-hydroxyalkenylquinolines have antimicrobial activity against other species. We show that Bacillus subtilis strain 168 is particularly susceptible to N -oxidated methylalkenylquinolines (HMAQ-NOs). We confirmed that HMAQ-NO biosynthesis requires the previously unstudied protein HmqL. These results provide new information about the biology of 2-alkyl-4(1 H )-quinolones, particularly the methylated 4-hydroxyalkenylquinolines, which are unique to B. thailandensis This study also has importance for understanding B. thailandensis secondary metabolites and has implications for potential therapeutic development., (Copyright © 2020 American Society for Microbiology.)
- Published
- 2020
- Full Text
- View/download PDF
35. Indwelling urethral versus suprapubic catheters in nursing home residents: determining the safest option for long-term use.
- Author
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Gibson KE, Neill S, Tuma E, Meddings J, and Mody L
- Subjects
- Aged, Aged, 80 and over, Bacterial Infections epidemiology, Bacterial Infections prevention & control, Female, Humans, Incidence, Male, Middle Aged, Nursing Homes, Catheter-Related Infections epidemiology, Catheter-Related Infections prevention & control, Catheterization methods, Catheters, Indwelling adverse effects, Urinary Tract Infections epidemiology, Urinary Tract Infections prevention & control
- Abstract
Background: The incidence of infectious complications has not been previously compared for two types of common urinary catheters used in the long-term care setting: indwelling urethral catheters and suprapubic catheters., Aim: To compare catheter-associated urinary tract infection (CAUTI) rates and multidrug-resistant organism (MDRO) colonization between nursing home residents with indwelling urethral and suprapubic catheters., Methods: Participants included 418 nursing home residents with an indwelling device enrolled in a previously published prospective targeted infection prevention study conducted between 2010 and 2013. Resident age, gender, function, comorbidities, and information on infections, antibiotic use, and recent hospitalizations were obtained at study enrolment, day 14, and every 30 days thereafter for up to one year. Microbiological samples were obtained from several anatomic sites at each visit. Cox proportional hazard models were adjusted for facility-level clustering and other covariates., Findings: In all, 208 study participants had an indwelling urinary catheter, contributing 21,700 device-days; 173 (83%) with a urethral catheter, 35 (17%) with a suprapubic catheter. After covariate adjustment, the suprapubic group had a lower incidence of CAUTI (6.6 vs 8.8 per 1000 device-days; P = 0.05), were half as likely to be hospitalized (hazard ratio (HR) = 0.46; P < 0.01) and were 23% less likely to have had antibiotics in the past 30 days (HR = 0.77; P = 0.02). Among residents catheterized ≥90 days, the mean number of MDROs isolated in the suprapubic group was significantly higher than in the urethral group (0.57 vs 0.44; P = 0.01). Ciprofloxacin-resistant Gram-negative bacilli were frequent in both groups., Conclusion: Residents with a suprapubic catheter may have fewer CAUTIs, less hospitalization and less antibiotic use, but are more likely colonized with MDROs., (Published by Elsevier Ltd.)
- Published
- 2019
- Full Text
- View/download PDF
36. IL-12p70-dependent Th1 induction by human B cells requires combined activation with CD40 ligand and CpG DNA.
- Author
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Wagner M, Poeck H, Jahrsdoerfer B, Rothenfusser S, Prell D, Bohle B, Tuma E, Giese T, Ellwart JW, Endres S, and Hartmann G
- Subjects
- B-Lymphocyte Subsets metabolism, Cell Division immunology, Cells, Cultured, DNA-Binding Proteins biosynthesis, Down-Regulation immunology, Drug Synergism, Humans, Immunoglobulin M biosynthesis, Immunologic Memory, Interleukin-10 biosynthesis, Interleukin-12 antagonists & inhibitors, Interleukin-12 biosynthesis, Interleukin-4 pharmacology, Interleukin-6 metabolism, Interphase immunology, Lipopolysaccharides pharmacology, Membrane Glycoproteins metabolism, Protein Subunits antagonists & inhibitors, Protein Subunits biosynthesis, Receptors, Antigen, B-Cell immunology, Receptors, Antigen, B-Cell metabolism, Receptors, Antigen, B-Cell physiology, Receptors, Cell Surface biosynthesis, Receptors, Cell Surface metabolism, T-Lymphocyte Subsets cytology, T-Lymphocyte Subsets immunology, Th1 Cells metabolism, Toll-Like Receptor 4, Toll-Like Receptor 9, Toll-Like Receptors, Tumor Necrosis Factor-alpha biosynthesis, Adjuvants, Immunologic physiology, B-Lymphocyte Subsets immunology, CD40 Ligand physiology, CpG Islands immunology, Interleukin-12 physiology, Lymphocyte Activation immunology, Oligodeoxyribonucleotides pharmacology, Protein Subunits physiology, Th1 Cells immunology
- Abstract
The detection of microbial molecules via Toll-like receptors (TLR) in B cells is not well characterized. In this study, we found that both naive and memory B cells lack TLR4 (receptor for LPS) but express TLR9 (receptor for CpG motifs) and produce IL-6, TNF-alpha, and IL-10 upon stimulation with CpG oligonucleotides (ODN), synthetic mimics of microbial DNA. Consistent with the lack of TLR4, purified B cells failed to respond to LPS. Similar to CpG ODN, CD40 ligand (CD40L) alone induced IL-6, TNF-alpha, and IL-10. Production of these cytokines as well as IgM synthesis was synergistically increased when both CpG ODN and CD40L were combined. Unlike IL-6, TNF-alpha, and IL-10, the Th1 cytokine IL-12p70 was detected only when both CpG ODN and CD40L were present, and its induction was independent of B cell receptor cross-linking. CpG ODN did not increase the capacity of CD40L-activated B cells to induce proliferation of naive T cells. However, B cells activated with CpG ODN and CD40L strongly enhanced IFN-gamma production in developing CD4 T cells via IL-12. Together, these results demonstrate that IL-12p70 production in human B cells is under the dual control of microbial stimulation and T cell help. Our findings provide a molecular basis for the potent adjuvant activity of CpG ODN to support humoral immune responses observed in vivo, and for the limited value of LPS.
- Published
- 2004
- Full Text
- View/download PDF
37. Recent advances in immunostimulatory CpG oligonucleotides.
- Author
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Rothenfusser S, Tuma E, Wagner M, Endres S, and Hartmann G
- Subjects
- Adjuvants, Immunologic metabolism, Animals, B-Lymphocytes, DNA-Binding Proteins biosynthesis, DNA-Binding Proteins genetics, DNA-Binding Proteins immunology, Dendritic Cells immunology, Dendritic Cells metabolism, Humans, Interferon-gamma immunology, Interferon-gamma metabolism, Killer Cells, Natural drug effects, Mice, Monocytes drug effects, Oligonucleotides metabolism, Receptors, Cell Surface biosynthesis, Receptors, Cell Surface genetics, Receptors, Cell Surface immunology, Signal Transduction immunology, T-Lymphocytes drug effects, Toll-Like Receptor 9, Adjuvants, Immunologic therapeutic use, CpG Islands immunology, Oligonucleotides immunology, Oligonucleotides therapeutic use
- Abstract
The vertebrate immune system has evolved a mechanism to detect CpG motifs within microbial DNA (CpG DNA). Synthetic oligonucleotides containing CpG motifs (CpG ODNs) are potent immunomodulatory molecules and outstanding vaccine adjuvants. A number of recent findings have greatly improved our understanding of the biology of CpG DNA, and the immunological effects of CpG DNA are now recognized to be distinct in mouse and human. The plasmacytoid dendritic cell (PDC) was identified to play a pivotal role in mediating CpG-induced immune responses. So far, the B-cell is the only other immune cell subset in humans besides the PDC, equipped with the toll-like receptor-9 to detect CpG motifs. The information on these two prime CpG-sensitive cells has allowed the identification of novel CpG ODNs with distinct functional activity. Together with exciting contributions from animal studies, the way seems to be paved for the successful clinical development of this novel class of molecular therapeutics.
- Published
- 2003
38. Plasmacytoid dendritic cells: the key to CpG.
- Author
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Rothenfusser S, Tuma E, Endres S, and Hartmann G
- Subjects
- B-Lymphocytes drug effects, B-Lymphocytes immunology, Dendritic Cells physiology, Humans, Membrane Glycoproteins immunology, Receptors, Cell Surface genetics, Receptors, Cell Surface immunology, T-Lymphocytes drug effects, T-Lymphocytes immunology, Toll-Like Receptor 7, Toll-Like Receptor 9, Toll-Like Receptors, Adjuvants, Immunologic pharmacology, Dendritic Cells immunology, Interleukin-12 biosynthesis, Oligodeoxyribonucleotides immunology, Receptors, Cell Surface biosynthesis
- Abstract
The vertebrate immune system has established TLR9 to detect microbial DNA based on unmethylated CG dinucleotides within certain sequence contexts (CpG motifs). In humans, the expression of toll-like receptor 9 (TLR9) is restricted to B cells and plasmacytoid dendritic cells (PDC). The PDC is characterized by the ability to rapidly synthesize large amounts of type I IFN (IFN-alpha and IFN-beta) in response to viral infection. In contrast to other dendritic cell subsets which express a broad profile of TLRs, the TLR profile in PDC is restricted to TLR7 and TLR9. So far, CpG DNA is the only defined microbial molecule recognized by PDC. An intriguing feature of PDC is its ability to simultaneously produce the two major Th1-inducing cytokines in humans, IFN-alpha and IL-12, both at high levels. The ratio of IFN-alpha versus IL-12 and the quantity of these cytokines are regulated by T helper cell-mediated costimulation via CD40 ligation. The ratio also depends on the differentiation stage of the PDC at the time of stimulation and the type of CpG ODN used. We propose a model in which the establishment of Th1 responses in vivo is improved by appropriately stimulated PDC that otherwise - in the absence of CpG DNA--support Th2 or Th0 responses and thus have been called DC2.
- Published
- 2002
- Full Text
- View/download PDF
39. Combined dendritic cell- and CpG oligonucleotide-based immune therapy cures large murine tumors that resist chemotherapy.
- Author
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Heckelsmiller K, Beck S, Rall K, Sipos B, Schlamp A, Tuma E, Rothenfusser S, Endres S, and Hartmann G
- Subjects
- Animals, CD8-Positive T-Lymphocytes immunology, Colonic Neoplasms pathology, Female, Fluorouracil administration & dosage, Leucovorin administration & dosage, Mice, Mice, Inbred BALB C, Tumor Cells, Cultured, Adjuvants, Immunologic therapeutic use, Antigens, Neoplasm immunology, Cancer Vaccines immunology, Colonic Neoplasms therapy, Dendritic Cells immunology, Oligodeoxyribonucleotides therapeutic use
- Abstract
The use of dendritic cells (DC) loaded with tumor antigen is one of the most advanced approaches in cancer immunotherapy. CpG motifs within microbial DNA detected by toll-like receptor 9 are responsible for the favorable properties of CpG oligodeoxynucleotides (ODN) as immune modulators. In this study, mature antigen-pulsed DC or peritumoral injections of CpG ODN, both effective for the treatment of small established tumors, were almost ineffective against large established tumors (1-cm diameter) in a syngeneic murine colon carcinoma model. For large tumors, the antitumor activity of mature antigen-pulsed DC was strongly increased by coinjection of CpG ODN, resulting in a transient control of tumor growth. Rejection of large tumors and long-term cure of mice was achieved by combining injection of antigen-pulsed DC plus CpG ODN at a site distant to the tumor with peritumoral injections of CpG ODN. Depletion of CD8 T cells abrogated the therapeutic activity. Large numbers of DEC-205-positive DC infiltrated the tumor in treated mice. Therapy with 5-fluorouracil and leucovorin was unable to control tumors of the same size. In conclusion, we demonstrate that the immune system, provided that appropriate stimulation with DC and CpG ODN is given, has the potential to cure animals of large solid tumors in situations where even chemotherapy is not efficient.
- Published
- 2002
- Full Text
- View/download PDF
40. Plasmacytoid dendritic cells: a new cutaneous dendritic cell subset with distinct role in inflammatory skin diseases.
- Author
-
Wollenberg A, Wagner M, Günther S, Towarowski A, Tuma E, Moderer M, Rothenfusser S, Wetzel S, Endres S, and Hartmann G
- Subjects
- Cell Lineage immunology, Dendritic Cells chemistry, Flow Cytometry methods, Humans, Interleukin-3 Receptor alpha Subunit, Langerhans Cells cytology, Langerhans Cells immunology, Leukocyte Common Antigens analysis, Receptors, Interleukin-3 analysis, Skin cytology, Skin immunology, Dendritic Cells classification, Dendritic Cells immunology, Skin Diseases immunology, Skin Diseases pathology
- Abstract
Epidermal dendritic cells found in inflamed skin include Langerhans cells and the recently identified population of inflammatory dendritic epidermal cells. Another subset of dendritic cells in humans is the plasmacytoid dendritic cell in peripheral blood, which is characterized by the production of large amounts of type I interferon (interferon-alpha and interferon-beta) upon viral infection. We hypothesized that plasmacytoid dendritic cells might be involved in anti-viral defense mechanisms of the skin. Here we investigated plasmacytoid dendritic cells, inflammatory dendritic epidermal cells, and Langerhans cells in epidermal single cell suspensions of normal looking skin from healthy volunteers and of lesional skin from patients with different inflammatory skin diseases. Langerhans cells were found in normal and in inflamed skin samples. In normal skin, plasmacytoid dendritic cells and inflammatory dendritic epidermal cells were low or absent. Lesional skin samples from patients with psoriasis vulgaris and contact dermatitis contained relatively high numbers of both inflammatory dendritic epidermal cells and plasmacytoid dendritic cells. In contrast, many inflammatory dendritic epidermal cells but only very few plasmacytoid dendritic cells could be detected in atopic dermatitis lesions. Lupus erythematosus was characterized by high numbers of plasmacytoid dendritic cells but low numbers of inflammatory dendritic epidermal cells. These results demonstrate that in addition to resident Langerhans cells, plasmacytoid dendritic cells and inflammatory dendritic epidermal cells are selectively recruited to the skin lesions depending on the type of skin disease. The lack of plasmacytoid dendritic cells in atopic dermatitis may predispose atopic dermatitis patients to viral infections such as eczema herpeticum, a secondary infection of atopic dermatitis lesions with herpes simplex virus. The composition of dendritic cell subsets may help to clarify the etiology of inflammatory skin diseases and forms the basis for therapeutic intervention with selective microbial molecules such as immunostimulatory CpG oligonucleotides.
- Published
- 2002
- Full Text
- View/download PDF
41. [Identification of CD11c+ myeloid dentritic cells in adenoids and in nasal mucosa of patients with and without allergies].
- Author
-
Tuma E, Rothenfusser S, Hartmann G, and Wollenberg B
- Subjects
- Adenoids immunology, Child, Child, Preschool, Data Interpretation, Statistical, Flow Cytometry, Humans, Nasal Mucosa immunology, Adenoids cytology, CD11 Antigens, Dendritic Cells immunology, Nasal Mucosa cytology, Rhinitis, Allergic, Perennial immunology, Rhinitis, Allergic, Seasonal immunology
- Abstract
Background: Dendritic cells form a link between innate and acquired immunity. They are capable to detect pathogens based on the recognition of pathogen-associated microbial molecules and trigger the appropriate type of immune responses. In humans, three major subsets of dendritic cells can be distinguished, Langerhans cells of the skin, myeloid DC (MDC) and plasmacytoid DC (PDC). It was reported that PDC infiltrate nasal mucosa in allergen-induced rhinitis. Information about the role of MDC in nasal mucosa and the corresponding mucosa-associated lymphoid tissue, the nasopharyngeal adenoids, is limited., Patients and Methods: : Here we examined the presence of MDC in adenoids and in nasal mucosa of healthy individuals (n = 9) and in patients with allergic rhinitis. MDC were detected by flow cytometry by positive staining for MHC II and CD11c and the lack of lineage markers. Dead cells were excluded from analysis., Results: In adenoids, 0.4 % of all cells were MDC. Considerable numbers of MDC could also be detected in nasal mucosa. No difference was found between healthy individuals and patients with allergies (0.3 % vs. 0.45 % MDC; p = 0.12). Interestingly, MDC were absent in patients who received treatment with glucocorticoids, while very high numbers of MDC were found in patients who recently had upper respiratory tract infections., Conclusion: Our results demonstrate for the first time the presence of MDC in nasal mucosa. MDC numbers were similar in healthy individuals and in patients with allergy. This study forms the basis for examining the role of MDC in the pathogenesis of allergic rhinitis, and for the modulation of MDC functional activity with microbial molecules such as CpG oligonucleotides.
- Published
- 2002
- Full Text
- View/download PDF
42. IL-1 receptor antagonist production by isolated mononuclear cells is a better indicator of bioincompatibility of hemodialysis membranes than that by stimulated whole blood.
- Author
-
Tuma E, Eigler A, Toepfer M, Endres S, and Schiffl H
- Subjects
- Adult, Aged, Biomarkers blood, Cross-Over Studies, Female, Humans, Interleukin 1 Receptor Antagonist Protein, Male, Middle Aged, Biocompatible Materials adverse effects, Cellulose analogs & derivatives, Leukocytes, Mononuclear immunology, Membranes, Artificial, Renal Dialysis, Sialoglycoproteins blood
- Published
- 2000
- Full Text
- View/download PDF
43. Family socioeconomic status and adolescent attitudes to authority.
- Author
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TUMA E and LIVSON N
- Subjects
- Adolescent, Humans, Attitude, Social Class, Sociology
- Published
- 1960
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