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1.
J Heart Lung Transplant ; 20(9): 928-34, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11557186

RESUMO

BACKGROUND: We prospectively compared the hybrid capture system (HCS) assay with conventional cell culture and shell vial assay for the detection of cytomegalovirus (CMV) infection and disease in the lung transplant population. METHODS: Between January 1999 and February 2000, 34 lung transplant patients at Loyola University Medical Center, who were considered to be at risk for CMV disease, underwent surveillance testing for CMV cell culture, shell vial assay and HCS assay according to a pre-determined schedule. In addition, bronchoscopy with bronchoalveolar lavage (BAL) and transbronchial biopsy were performed at regular intervals and for clinical indications. All BAL samples were sent for CMV cultures and biopsy specimens were analyzed for histopathologic evidence of CMV by immunoperoxidase staining using antibody to early immediate nuclear antigen. RESULTS: Ten patients developed CMV disease/syndrome during the course of the study. The sensitivity, specificity, positive predictive value and negative predictive value were >90% for the HCS assay. The sensitivity of the HCS assay (90%) was statistically significantly higher than the sensitivity of either the SV assay (40%) or the cell culture (50%). In addition, the HCS assay was able to detect CMV 50 +/- 67 days prior to clinical evidence of CMV disease and an average of 36 days prior to the other detection techniques. CONCLUSION: The HCS assay is a sensitive diagnostic technique able to reliably detect CMV disease earlier than other diagnostic methods in the lung transplant population. Future studies may be able to evaluate whether pre-emptive anti-viral therapy targeted to specific viral loads using the HCS assay will be beneficial in preventing morbidity associated with CMV disease.


Assuntos
Infecções por Citomegalovirus/diagnóstico , Infecções por Citomegalovirus/etiologia , Citomegalovirus , Transplante de Pulmão , Hibridização de Ácido Nucleico/métodos , Organofosfonatos , Carga Viral , Adulto , Antivirais/uso terapêutico , Técnicas de Cultura de Células , Cidofovir , Citomegalovirus/genética , Citomegalovirus/isolamento & purificação , Infecções por Citomegalovirus/mortalidade , Citosina/análogos & derivados , Citosina/uso terapêutico , DNA Viral/sangue , Feminino , Ganciclovir/uso terapêutico , Humanos , Illinois , Imunização Passiva , Masculino , Pessoa de Meia-Idade , Compostos Organofosforados/uso terapêutico , Valor Preditivo dos Testes , Estudos Prospectivos , Kit de Reagentes para Diagnóstico , Sensibilidade e Especificidade , Análise de Sobrevida , Síndrome
3.
AACN Clin Issues ; 12(2): 186-201, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11759547

RESUMO

Lung transplantation is a growing surgical option for patients with end-stage lung and pulmonary vascular diseases. After completing an extensive evaluation and meeting the selection criteria, patients are listed for either single or bilateral-sequential lung transplantation. Immediate postoperative management requires detailed attention to fluid management, monitoring for infection, reperfusion injury, pulmonary hygiene, and pain management. Length of stay depends on the patient's condition before transplant and postoperative complications. Discharge from the hospital can be as early as 7 days after transplantation. Newer immunosuppressive medications offer more options for treating and preventing rejection. Advanced practice nurses, such as coordinators, case managers, nurse practitioners, and clinical nurse specialists, are uniquely positioned to play key roles in coordinating the care of transplant patients across settings and both before and after the transplant procedure. The perioperative needs of lung transplant patients and the impact of this complex procedure on the recipients' and family's quality of life merit further investigation by clinicians and researchers.


Assuntos
Transplante de Pulmão/enfermagem , Assistência Perioperatória , Qualidade de Vida , Humanos , Imunossupressores/uso terapêutico , Transplante de Pulmão/reabilitação , Diagnóstico de Enfermagem , Seleção de Pacientes
4.
J Heart Lung Transplant ; 19(12): 1199-204, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11124490

RESUMO

BACKGROUND: Currently the most important limitation in lung transplantation is donor availability. Although liberalization of donor criteria may aid in expanding the donor pool, the long-term effects of the use of "marginal" or "extended" donors remains unexplored. METHODS: In this study, we included all patients who underwent lung transplantation from January 1996 to December 1999 at Loyola University Medical Center. We categorized patients as either receiving lungs from an "ideal" donor or an "extended" donor. Extended donors were defined as having any 1 of the following criteria: donor age > 55 years, tobacco history > 20 pack years, presence of infiltrate on chest x-ray, donor ventilator time > 5 days, or donor use of inhaled drugs (cocaine or marijuana). We then compared the 2 groups with regard to short-term (operating room [OR] complications, intensive care unit [ICU] complications) and long-term outcomes (1-year pulmonary function and survival). RESULTS: Sixty-one (54%) patients received lungs from ideal donors and 52 (46%) patients received lungs from extended donors as defined above. We observed no significant differences between the 2 groups in OR complications (cardiopulmonary bypass, bleeding complications, life-threatening arrhythmias) or ICU complications (pneumonia, airway dehiscence, reoperation within 30 days related to transplantation). In addition, the 2 groups had similar median intubation times (21 hours in the ideal donor group and 20 hours in the extended donor group; p = n.s.), hospital length of stay (14+/-12 days in the ideal donor group and 12+/-8 days in the extended donor group; p = n.s.), and hospital survival (80% and 88% in the ideal and extended donor groups, respectively). One-year follow-up revealed similar pulmonary function (forced expiratory volume in 1 sec [FEV(1)] = 2.4 liters and 2.4 liters in the recipients of bilateral ideal and extended donors, respectively, and FEV(1) = 1.9 liters and 1.5 liters in the recipients of single ideal and extended donors) and survival (72% and 79% in the ideal and extended donor groups, respectively; p = n.s.) between the 2 groups. CONCLUSIONS: Liberalization of donor criteria does not affect outcome in the first year after lung transplantation. By liberalizing donor criteria, we can expand the donor pool while assessing other possible mechanisms to increase donor availability.


Assuntos
Transplante de Pulmão , Doadores de Tecidos/classificação , Obtenção de Tecidos e Órgãos , Fatores Etários , Arritmias Cardíacas/etiologia , Perda Sanguínea Cirúrgica , Ponte Cardiopulmonar , Distribuição de Qui-Quadrado , Transtornos Relacionados ao Uso de Cocaína/fisiopatologia , Cuidados Críticos , Feminino , Seguimentos , Volume Expiratório Forçado/fisiologia , Humanos , Complicações Intraoperatórias , Intubação Intratraqueal , Tempo de Internação , Estudos Longitudinais , Pulmão/fisiopatologia , Pneumopatias/fisiopatologia , Transplante de Pulmão/efeitos adversos , Transplante de Pulmão/classificação , Masculino , Fumar Maconha/fisiopatologia , Pessoa de Meia-Idade , Pneumonia/etiologia , Complicações Pós-Operatórias , Reoperação , Respiração Artificial , Estudos Retrospectivos , Fumar/fisiopatologia , Deiscência da Ferida Operatória/etiologia , Taxa de Sobrevida , Fatores de Tempo , Obtenção de Tecidos e Órgãos/organização & administração , Resultado do Tratamento
5.
J Pediatr Psychol ; 24(6): 491-8, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10608100

RESUMO

OBJECTIVE: To investigate the independent and combined contributions of neurocognitive and family functioning to mother-reported behavior problems in children with sickle cell disease (SCD) and evaluate the factor structure of the Family Environment Scale (FES) with African American families. METHOD: The study sample included 289 children enrolled in the multisite Cooperative Study of Sickle Cell Disease. The study protocol included neuropsychological evaluation and brain magnetic resonance imaging (MRI) of the children, and mothers completed the Child Behavior Checklist and Family Environment Scale. RESULTS: With child and maternal demographic parameters controlled, conflicted family functioning, but not neurocognitive functioning, accounted for a significant portion of the variance in mother-reported behavior problems. The factor structure of the FES for families of children with SCD was found to be similar to that for other families. CONCLUSIONS: Family functioning may be a salient target for fostering adaptation to chronic childhood illness.


Assuntos
Anemia Falciforme/complicações , Encéfalo/anatomia & histologia , Transtornos do Comportamento Infantil/complicações , Cognição/fisiologia , Família/psicologia , Adaptação Psicológica/fisiologia , Criança , Transtornos do Comportamento Infantil/diagnóstico , Pré-Escolar , Doença Crônica , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Testes Neuropsicológicos
6.
J Pediatr ; 133(2): 293-5, 1998 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9709726

RESUMO

Diphenhydramine is generally considered an innocuous drug with a minimal risk for abuse and untoward side effects. We describe children and adolescents with chronic hematologic and oncologic diseases who exhibited drug-seeking behavior or anticholinergic symptoms with the use of diphenhydramine. These cases illustrate that the assumption that this drugs is without significant adverse effects may be unwarranted, especially for children and adolescents with chronic diseases.


Assuntos
Difenidramina/efeitos adversos , Antagonistas dos Receptores Histamínicos H1/efeitos adversos , Transtornos Relacionados ao Uso de Substâncias/etiologia , Adolescente , Adulto , Criança , Doença Crônica , Difenidramina/uso terapêutico , Feminino , Doenças Hematológicas/tratamento farmacológico , Antagonistas dos Receptores Histamínicos H1/uso terapêutico , Humanos , Masculino , Neoplasias/tratamento farmacológico , Risco
7.
J Pediatr Hematol Oncol ; 19(2): 145-50, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9149746

RESUMO

PURPOSE: Bone marrow transplantation (BMT), particularly preparative regimens, may have a significant impact on the developing nervous system. However, the effects of various BMT regimens on children's growth and development have been poorly documented to date. Twins serve as ideal subjects to study the impact of medical treatment, since they control for nonmedical (genetic and environmental) influences upon neurodevelopmental outcome. PATIENTS AND METHODS: Two cases of monozygotic twins are presented to illustrate the impact of BMT regimens. Growth data and neurocognitive testing are presented for each patient (affected twin) in relation to his/her syngeneic BMT donor and case control (control twin). RESULTS: These two cases illustrate the growth retardation that has been reported after BMT. However, changes in growth trends across twins appear to have begun after diagnosis, rather than after BMT per se. Comparisons of cognitive test results within these twin pairs illustrate learning problems in the affected twins. However, there was also evidence of learning anomalies in the unaffected twins. CONCLUSIONS: Results underscore the importance of longitudinal assessment in order to identify the side effects of BMT regimens for children. Differences across the two cases highlight important research questions regarding variables associated with patients, disease, and treatment (e.g., age at the time of BMT, previous neurotoxic treatments, underlying disease) and emphasize the importance of controls in this line of research.


Assuntos
Transplante de Medula Óssea/efeitos adversos , Deficiências do Desenvolvimento/etiologia , Transtornos do Crescimento/etiologia , Neuroblastoma/terapia , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Deficiências do Desenvolvimento/fisiopatologia , Feminino , Transtornos do Crescimento/fisiopatologia , Humanos , Lactente , Masculino , Gêmeos
8.
Solid State Nucl Magn Reson ; 10(1-2): 53-61, 1997 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9472792

RESUMO

The resolution enhancement conferred by numerical deconvolution of powder pattern spectra to spectra characteristic of a single alignment greatly simplifies solid state NMR spectral analysis. This is especially beneficial when the spectrum is a superposition of signals from multiple environments or sites of labelling. We have developed an innovative method to deconvolute (depake) spectra governed by axially symmetric second rank tensor interactions which possess a P2(cos theta) dependence upon orientation, where theta is the angle between the symmetry axis and the external magnetic field. Our approach differs substantially from previously published procedures which are iterative or require matrix inversion and, hence, are slow. The new method, instead, utilizes weighting functions in time and frequency domains to facilitate a rapidly executed solution based upon fast Fourier transformation (FFT). Its efficacy is demonstrated with 2H and 31P NMR data for model membranes.


Assuntos
Análise de Fourier , Ressonância Magnética Nuclear Biomolecular/métodos , Bicamadas Lipídicas/química , Membranas/química , Fósforo , Pós/química , Prótons
11.
J Pediatr Psychol ; 21(4): 505-16, 1996 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8863460

RESUMO

Outlined the issues in informed consent, as well as goals for involving children and adolescents in decisions regarding their own medical treatment. This paper reviews the developmental and clinical considerations, and provides recommendations, for determining particular children's level of involvement. Finally, there are distinct roles for pediatric psychologists in this process, which are described. As medical treatment becomes increasingly sophisticated, there is an obligation for pediatric psychologists to appreciate the ethical and clinical issues in medical decision making for families.


Assuntos
Tomada de Decisões , Consentimento Livre e Esclarecido , Participação do Paciente/métodos , Psicologia da Criança/métodos , Adolescente , Criança , Desenvolvimento Infantil , Humanos , Consentimento Livre e Esclarecido/legislação & jurisprudência , Competência Mental/legislação & jurisprudência , Competência Mental/psicologia , Aceitação pelo Paciente de Cuidados de Saúde/psicologia , Participação do Paciente/legislação & jurisprudência , Participação do Paciente/psicologia , Relações Profissional-Família , Psicologia do Adolescente
12.
J Heart Lung Transplant ; 14(5): 883-90, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-8800724

RESUMO

BACKGROUND: Aspergillus infection is a known complication of transplantation. METHODS: We describe our experience with 37 patients who received lung transplants over 2 years at Loyola University Medical Center. All patients who had evidence of aspergillus on culture of clinical specimens or had biopsies with hyphal forms consistent with aspergillus were categorized according to the clinical manifestations. Important risk factors were analyzed in comparison with other lung transplant recipients during the same period. RESULTS: The incidence of invasive aspergillosis was high (16%). No patient with disseminated disease survived. Locally invasive disease responded well to treatment with amphotericin B and itraconazole. CONCLUSIONS: Lung transplantation patients may have a higher incidence of aspergillosis as compared with other transplantation groups. Prophylactic measures need to be explored.


Assuntos
Aspergilose/etiologia , Pneumopatias Fúngicas/etiologia , Transplante de Pulmão/efeitos adversos , Adulto , Idoso , Aspergilose/tratamento farmacológico , Aspergilose/mortalidade , Estudos de Casos e Controles , Feminino , Humanos , Pneumopatias Fúngicas/tratamento farmacológico , Pneumopatias Fúngicas/mortalidade , Transplante de Pulmão/mortalidade , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Taxa de Sobrevida
13.
Cancer Pract ; 3(1): 47-53, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-7704061

RESUMO

A growing literature documents the deleterious effects of radiation therapy in children treated for malignant brain tumors. However, the clinical relevance of previous research has been limited by reliance on global IQ and achievement test scores. The present study of a sample of long-term survivors of medulloblastoma examined their cognitive and socioemotional functioning in depth with standardized psychologic measures. Participants' levels of intellectual functioning ranged from moderately mentally retarded to low average, with marked scatter across individual skills. Thirty-nine percent of participants had formal learning disabilities, with achievement substantially below their learning potential. In terms of specific areas of deficit, almost one half the patients tested (47%) showed considerable impairment in perceptual-motor coordination, fine-motor dexterity, attention and concentration, sequencing, and memory, particularly visual memory. More than one half of the sample (54%) was also described as displaying severe impairment in terms of maladaptive behaviors. Results are discussed in terms of the implications for special education, everyday skills, and psychosocial program development.


Assuntos
Neoplasias Cerebelares/complicações , Pessoas com Deficiência , Meduloblastoma/complicações , Adolescente , Adulto , Neoplasias Cerebelares/terapia , Criança , Estudos de Coortes , Humanos , Meduloblastoma/terapia , Desenvolvimento de Programas , Sobreviventes , Resultado do Tratamento
14.
Biochemistry ; 33(23): 7203-10, 1994 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-8003485

RESUMO

The properties of aqueous multilamellar dispersions of [2H31]16:0-alpha 18:3 PC (1-[2H31]palmitoyl-2-cis,cis,cis-octa-9,12,15- trienoylphosphatidylcholine) and of [2H31]16:0-gamma 18:3 PC (1-[2H31]palmitoyl-2-cis,cis,cis-octa-6,9,12-trienoylphosphatid ylcholine) were compared by broadline 2H NMR spectroscopy. These isomeric phospholipids differ only in the location of the unsaturations in the sn-2 chain. The alpha 18:3 chain has double bonds at delta 9, 12, and 15 positions whereas in the gamma 18:3 chain they are at positions delta 6, 9, and 12. Moment analysis of spectra recorded as a function of temperature reveals dramatically distinct phase behavior for the two isomers. The gel to liquid crystalline transition for [2H31]16:0-alpha 18:3 PC membranes exhibits broad hysteresis which is characterized by a mid point temperature of -9 degrees C and -20 degrees C on heating and cooling, respectively. In contrast, the phase transition of [2H31]16:0-gamma 18:3 PC membranes does not exhibit hysteresis and occurs over a lower temperature range centred on -27 degrees C. Appreciably different molecular ordering also exists within the membranes in the liquid crystalline state. Average order parameters SCD are smaller in [2H31] 16:0-alpha 18:3 PC than in [2H31]16:0-gamma 18:3 PC by 10% at the same temperature and by 20% at equal reduced temperature. Smoothed order parameter profiles generated from depaked spectra clarify the nature of the difference.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Ácidos Graxos Ômega-3/química , Ácidos Graxos Insaturados/química , Lipídeos de Membrana/química , Fosfolipídeos/química , Deutério , Ácidos Graxos Ômega-6 , Isomerismo , Bicamadas Lipídicas , Espectroscopia de Ressonância Magnética , Temperatura
15.
J Neurosurg ; 80(6): 1004-10, 1994 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8189255

RESUMO

The reported success of treatment for children with medulloblastoma must be balanced against the effect that treatment has on the quality of life of long-term survivors. The outcome of long-term survivors reported in previous studies has been conflicting. The authors evaluate the mental and behavioral skills of a group of medulloblastoma survivors from their institution, all of whom had survived for more than 5 years postdiagnosis. A review of the institutional records yielded 32 patients. Twenty-three families were interviewed by telephone and, of these, 13 subjects came to the hospital for detailed neuropsychological and neurological evaluations. Intelligence quotient (IQ) was less than 90 for all participants tested, and patients diagnosed before the age of 3 years had lower IQ scores on average than those diagnosed later. Mean IQ and achievement test scores in reading, spelling, and mathematics were all higher in survivors who had undergone shunting. Achievement test results were often not in accord with intellectual potential, and individual intellectual skills varied widely. Perceptual-motor task performance was below average in more than 50% of the participants, but motor dexterity was more severely affected than perception. Problems in learning and a delay in both physical growth and development were seen in a majority of participants. This study directs attention to the serious difficulties faced by long-term survivors of medulloblastoma and their families, and underscores the importance of routine neuropsychological testing. Moreover, the study provides further impetus to seek alternatives to irradiation in the treatment of malignant brain tumors.


Assuntos
Neoplasias Cerebelares/reabilitação , Meduloblastoma/reabilitação , Qualidade de Vida , Adolescente , Neoplasias Cerebelares/mortalidade , Neoplasias Cerebelares/terapia , Criança , Pré-Escolar , Terapia Combinada , Escolaridade , Feminino , Humanos , Lactente , Inteligência , Masculino , Meduloblastoma/mortalidade , Meduloblastoma/terapia , Exame Neurológico , Testes Neuropsicológicos , Prognóstico , Análise de Sobrevida
16.
J Consult Clin Psychol ; 62(2): 324-32, 1994 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-8201070

RESUMO

The literature suggests that optimal adjustment to relatively uncontrollable stressors may require adjusting oneself to the stressors rather than trying to alter them. This possibility was explored, for low-controllability stressors (e.g., painful medical procedures) associated with leukemia. Children's reports of coping strategies and goals were classified as primary control coping (attempts to alter objective conditions), secondary control coping (attempts to adjust oneself to objective conditions), or relinquished control (no attempt to cope). Secondary control coping was positively associated with (a) general behavioral adjustment assessed by the Child Behavior Checklist and (b) illness-specific adjustment assessed by children's own distress ratings and by behavioral observations during painful procedures. All significant group differences showed better adjustment among secondary control children than among the primary or relinquished groups.


Assuntos
Adaptação Psicológica , Controle Interno-Externo , Leucemia-Linfoma Linfoblástico de Células Precursoras/psicologia , Papel do Doente , Alopecia/induzido quimicamente , Alopecia/psicologia , Antineoplásicos/administração & dosagem , Antineoplásicos/efeitos adversos , Exame de Medula Óssea/psicologia , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Determinação da Personalidade , Punção Espinal/psicologia , Vômito/induzido quimicamente , Vômito/psicologia
17.
J Pediatr ; 123(3): 457-62, 1993 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8355126

RESUMO

To assess whether a simple nonrestrictive method of determining nutrient intake could be applied to premature infants, we compared actual measured formula intake during a 7-day period with intake calculated from deuterium dilution in 13 hospitalized, growing, premature newborn infants. An oral dose of deuterium oxide (D2O) was administered, and urine samples were analyzed by deuterium nuclear magnetic resonance spectrometry for D2O concentration. Using an exponential model, we calculated formula intake from the decline in D2O concentration during the 7-day study period. Intake as assessed by the deuterium model correlated well with actual intake (r = 0.93; p < 0.001). However, because the deuterium dilution model measures both dietary and nondietary water intake (metabolic and cutaneous water influx), deuterium dilution-derived intake exceeded actual intake by 25 +/- 18 ml/kg per day (16% +/- 11%). When corrections were applied to account for nondietary water intake, deuterium dilution-derived nutrient intake (160 +/- 30 ml/kg per day) closely approximated actual intake (155 +/- 17 ml/kg per day). If corrections are made for nondietary water intake, the deuterium dilution method may be a useful nonrestrictive method of measuring nutrient intake in a variety of neonatal populations.


Assuntos
Água Corporal/metabolismo , Recém-Nascido Prematuro/metabolismo , Avaliação Nutricional , Antropometria , Deutério , Nutrição Enteral , Humanos , Recém-Nascido , Recém-Nascido Prematuro/crescimento & desenvolvimento , Espectroscopia de Ressonância Magnética , Modelos Biológicos
18.
Chest ; 102(4): 1273-4, 1992 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-1395782

RESUMO

A 63-year-old man who underwent single lung transplantation for advanced emphysema had a postoperative course complicated by asymptomatic bronchial dehiscence associated with a large broncholith. The stone eventually caused airway obstruction requiring partial fragmentation and incomplete extrication. We suggest that calcified nodes of significant size be removed at the time of surgery in the lung transplant recipient.


Assuntos
Broncopatias/etiologia , Cálculos/etiologia , Transplante de Pulmão , Complicações Pós-Operatórias , Deiscência da Ferida Operatória , Broncopatias/diagnóstico , Broncopatias/terapia , Cálculos/diagnóstico , Cálculos/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Deiscência da Ferida Operatória/diagnóstico
20.
Immunology ; 43(3): 483-91, 1981 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-6454656

RESUMO

Bacterial ability to obtain iron in bovine serum or in media containing transferrin (Tr) or conalbumin (Ca) was investigated by using serum-resistant (virulent) and serum-sensitive (avirulent) strains of Escherichia coli and Salmonella typhimurium. Bacteria growing in bovine serum enriched with radioactive iron-saturated Tr or with radioactive iron-saturated enterobactin (E) did not acquire radioactive iron. It has been found that the passage of siderophore (Si)-iron complexes into bacteria is blocked in serum by Tr and in Ca-containing medium by Ca. The investigation of bacterial ability to take iron in synthetic media showed that bacteria take in Si-bound but no Tr-bound radioactive iron. In the absence of free iron, the growth of serum-exposed virulent bacteria was supported by their stored iron. Virulent bacteria passaged in medium void of usable iron became depleted in stored iron and did not grow in animal sera unless sera were enriched by the addition of exogenous iron. Experiments with serum-exposed avirulent bacteria showed that their growth in Si-enriched serum should not be attributed to the iron-providing activity of Si but to the stimulating effect of Si which facilitates the use of stored iron. As distinct from avirulent bacteria, virulent bacteria used stored iron without the stimulating activity of extracellular Si.


Assuntos
Escherichia coli/crescimento & desenvolvimento , Ferro/metabolismo , Salmonella typhimurium/crescimento & desenvolvimento , Sangue , Meios de Cultura , Enterobactina/metabolismo , Escherichia coli/metabolismo , Ácidos Hidroxâmicos/metabolismo , Radioisótopos de Ferro , Piperazinas/metabolismo , Salmonella typhimurium/metabolismo , Transferrina/metabolismo , Virulência
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