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1.
Niger J Clin Pract ; 27(5): 583-591, 2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38842707

RESUMEN

OBJECTIVES: To present a review of the clinical characteristics, preoperative and surgical management, and outcomes of patients with intra-articular calcaneal fractures who had open reduction and internal fixation (ORIF) and to offer some comments on and research ideas for the preoperative management of patients with these fractures. PATIENTS AND METHODS: We studied consecutive patients who had ORIF performed by a single surgeon for closed, intra-articular calcaneal fractures at our level-1 trauma center between 5/29/2012 and 3/20/2018. All inpatients were treated with a preoperative soft tissue management protocol, whereas outpatients were not. Data were obtained about demographic and clinical characteristics, times from injury to surgery, quality of fracture reductions, and complication rates. RESULTS: Mean follow-up for the 72 patients with 77 calcaneal fractures was 8.5 (range: 1-43) months, and 21 (27.3%) fractures received inpatient preoperative care with a soft tissue management protocol, while 56 (72.7%) received outpatient preoperative management. More of the fractures treated preoperatively as inpatients versus outpatients were classified as Sanders type III (66.7% vs. 32.1%) and type IV (8.9% vs. 4.8%) fractures and were associated with polytrauma (38.1% vs. 7.1%) and diabetes mellitus (9.5% vs. 5.4%), respectively. For all patients, the mean time from injury to surgery was 12.2 (range: 2.7-19.4) days, and the time was 6.3 days for inpatients and 14.4 days for outpatients, but the quality of fracture reductions and complication rates did not differ between these two groups. CONCLUSIONS: Patients with intra-articular calcaneal fractures treated as inpatients and receiving a preoperative soft tissue management protocol had outcomes after ORIF that were not inferior to those experienced by patients treated preoperatively as outpatients, despite a greater proportion of the inpatients having severe fractures, polytrauma, and diabetes mellitus. Dedicated preoperative soft tissue management protocols may be beneficial for patients with calcaneal fractures and warrant further study.


Asunto(s)
Calcáneo , Fijación Interna de Fracturas , Humanos , Calcáneo/lesiones , Calcáneo/cirugía , Femenino , Masculino , Adulto , Persona de Mediana Edad , Fijación Interna de Fracturas/métodos , Fracturas Intraarticulares/cirugía , Resultado del Tratamiento , Cuidados Preoperatorios/métodos , Anciano , Estudios Retrospectivos , Adulto Joven , Fracturas Óseas/cirugía , Adolescente , Reducción Abierta/métodos
2.
JDR Clin Trans Res ; 8(4): 394-401, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-35678084

RESUMEN

INTRODUCTION: Early childhood caries (ECC) is a complex oral disease that is prevalent in US children. OBJECTIVES: The purpose of this 2-y prospective cohort study was to examine baseline and time-dependent risk factors for ECC onset in initially caries-free preschool children. METHODS: A cohort of 189 initially caries-free children aged 1 to 3 y was recruited. At each 6-mo study visit, children were examined using the ICDAS index; salivary samples were collected to assess mutans streptococci (MS), lactobacilli, Candida species, salivary cortisol (prior and after a stressor), and salivary IgA. Diet and oral health behavior were assessed from parent report. Child and family stress exposure was assessed from measures of psychological symptoms, stressful life event exposure, family organization and violence exposure, and social support. Sociodemographic factors were also considered. A Kaplan-Meier estimator of survival function of time to ECC and a Cox proportional hazards model were used to identify predictors of ECC onset. RESULTS: Onset of ECC was associated with high salivary MS levels at baseline (log-rank test, P < 0.0001). Cox proportional hazards regression showed that the risk of dental caries significantly increased with salivary MS in log scale over the 6-mo period (hazard ratio, 1.08; P = 0.01). Other risk factors in the model did not reach statistical significance. CONCLUSION: Our results provide prospective evidence that an increase in salivary MS predicts ECC onset in young, initially caries-free children, confirming that a high salivary MS count likely plays a causal role in ECC onset, independent of covariates. KNOWLEDGE TRANSFER STATEMENT: These results suggest that we must focus on reducing salivary MS counts in young children and preventing or delaying MS colonization in infants and young children determined to be at risk for ECC.


Asunto(s)
Caries Dental , Lactante , Humanos , Preescolar , Estudios Prospectivos , Estudios Longitudinales , Caries Dental/epidemiología , Streptococcus mutans , Modelos de Riesgos Proporcionales
3.
JDR Clin Trans Res ; 7(2): 163-173, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-33719664

RESUMEN

INTRODUCTION: Early childhood caries (ECC) is a complex, multifactorial oral disease that is a major public health concern because it is prevalent, profoundly alters a child's quality of life, is difficult to treat effectively, and has a distressing tendency to recur following treatment. OBJECTIVES: The purpose of the study was to examine social, psychological, and behavioral predictors of salivary bacteria and yeast in young children at risk for ECC. METHODS: A sample of 189 initially caries-free preschool children was assessed for child stress physiology from salivary cortisol, child and family stress exposure, diet, oral health behaviors, and sociodemographic risks. Multiple logistic regression analysis was implemented to examine the associations between these risk factors and cariogenic microorganisms: mutans streptococci (MS), lactobacilli (LB), and Candida species. RESULTS: Higher baseline salivary cortisol (odds ratio [OR] = 6.26; 95% confidence level [CL], 1.69-23.16) and a blunted response to an acute laboratory stressor (OR = .56; 95% CL, .37-.83) were associated with an increased likelihood of elevated salivary MS (≥105 colony-forming units/mL) in caries-free children. Sociodemographic risk for cariogenic microorganisms was also found. Specifically, lower education attainment of the parent/primary caregiver was associated with children being more likely to carry salivary Candida species and elevated salivary MS; in addition, children from households with an unemployed parent/primary caregiver were more likely (OR = 3.13; 95% CL, 1.2-8.05) to carry salivary Candida species and more likely (OR = 3.03; 95% CL, 1.25-7.33) to carry elevated levels of MS and/or salivary Candida and/or LB. CONCLUSIONS: The impact of sociodemographic risk and stress physiology on cariogenic disease processes are evident prior to ECC onset. The findings provide novel data on the early onset of cariogenic processes in children and the importance of considering sociodemographic, psychosocial, and behavioral factors when judging ECC risk. KNOWLEDGE TRANSFER STATEMENT: The findings provide valuable and novel findings that, pre-ECC onset, the caries disease process is explicable from a detailed assessment of behavioral, sociodemographic, and psychosocial stress variables.


Asunto(s)
Caries Dental , Saccharomyces cerevisiae , Preescolar , Caries Dental/epidemiología , Humanos , Hidrocortisona , Lactobacillus , Calidad de Vida , Saliva/microbiología , Streptococcus mutans
4.
Oncogene ; 6(11): 2019-26, 1991 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-1658708

RESUMEN

The ATF/CRE binding site can mediate transcriptional activation by cAMP, the adenovirus E1A protein and the human T-cell leukaemia virus 1 (HTLV1) tax protein. A large number of different proteins bind specifically to this element either as homodimers or as heterodimers. Using GAL4-ATF/CREB fusions, we have investigated the regulatory functions of three members of this family. CREB1 (CREB) is strongly activated by cAMP and weakly activated by the E1A protein. In contrast, CREB2 (CRE-BP1, ATF2) is strongly activated by E1A but is insensitive to cAMP stimulation. ATF1 is weakly activated by cAMP but is not activated by E1A. All three proteins are insensitive to activation by the HTLV1 tax protein. The N-terminal region of CREB2, from amino acid residues 19 to 112, is both necessary and sufficient for E1A activation. This region contains a putative C2H2 metal-binding finger, and single amino acid substitutions of the cysteine residues severely decreased CREB2 activity. In contrast, mutations affecting a potential protein kinase A and casein kinase II phosphorylation site within this region had little effect.


Asunto(s)
Proteínas Sanguíneas/fisiología , Cricetinae/genética , Proteínas de Unión al ADN/biosíntesis , Regulación de la Expresión Génica/fisiología , Proteínas de Neoplasias/biosíntesis , Proteínas de Saccharomyces cerevisiae , Factores de Transcripción/fisiología , Factores de Transcripción Activadores , Proteínas Precoces de Adenovirus , Secuencia de Aminoácidos , Animales , Mapeo Cromosómico , Clonación Molecular , AMP Cíclico/fisiología , Proteína de Unión a Elemento de Respuesta al AMP Cíclico , Proteínas de Unión al ADN/genética , Proteínas Fúngicas , Productos del Gen tax/fisiología , Humanos , Datos de Secuencia Molecular , Mutación , Proteínas Oncogénicas Virales/fisiología , Plásmidos , Regiones Promotoras Genéticas , Transcripción Genética/fisiología , Activación Transcripcional , Transfección , Células Tumorales Cultivadas
5.
Mol Endocrinol ; 9(2): 255-65, 1995 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-7776975

RESUMEN

We have investigated the molecular basis of the variability of the somatostatin cAMP response element (CRE) function in different cell lines. All cells tested contain detectable levels of the CRE-binding protein CREB-1, which mediates transactivation in response to the cAMP-dependent protein kinase (protein kinase-A), in forms that can bind to a somatostatin CRE. Although both responsive and nonresponsive cells contain CREB-1 in heterodimers with activating transcription factor-1 (ATF-1), only cells that allow a cAMP response have a significant proportion of CREB-1 in a homodimeric form. Transfection experiments demonstrate that ATF-1 is capable of antagonizing CREB-1-dependent activation, suggesting that the ability of CREB-1 to mediate a cAMP response is down-regulated by heterodimer formation with ATF-1.


Asunto(s)
Proteína de Unión a Elemento de Respuesta al AMP Cíclico/antagonistas & inhibidores , AMP Cíclico/metabolismo , Proteínas de Unión al ADN , Regulación hacia Abajo , Secuencias Reguladoras de Ácidos Nucleicos , Somatostatina/genética , Factores de Transcripción/metabolismo , Factor de Transcripción Activador 1 , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Línea Celular , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Humanos , Datos de Secuencia Molecular , Mutación , Proteínas Recombinantes de Fusión/biosíntesis , Activación Transcripcional , Transfección
6.
Arch Intern Med ; 152(6): 1299-302, 1992 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-1599360

RESUMEN

The semiquantitative culture technique is a standard procedure for the laboratory diagnosis of catheter-associated infections and catheter-associated bacteremia. In a prospective observational study, we evaluated the clinical impact of the semiquantitative culture results on the treatment of the patient. Clinical impact was defined as a change in diagnosis or therapy on the basis of the semiquantitative culture result. One hundred fifty-seven catheters consecutively submitted from the surgical intensive care unit to the laboratory were studied. In 96% of the episodes, no clinical impact was observed. In the other 4%, clinical decisions were guided mainly by the concurrent positive blood cultures. Newer laboratory techniques that do not require removal of the catheter are needed to guide therapeutic decisions.


Asunto(s)
Cateterismo Venoso Central , Contaminación de Equipos/prevención & control , Control de Infecciones/métodos , Antibacterianos/uso terapéutico , Infecciones Bacterianas/tratamiento farmacológico , Infecciones Bacterianas/microbiología , Candida albicans/aislamiento & purificación , Enterococcus faecalis/aislamiento & purificación , Femenino , Humanos , Masculino , Estudios Prospectivos , Staphylococcus/aislamiento & purificación
7.
Drugs ; 37 Suppl 1: 37-43; discussion 69-77, 1989.
Artículo en Inglés | MEDLINE | ID: mdl-2474428

RESUMEN

Nedocromil sodium and sodium cromoglycate inhibited histamine release from rat peritoneal mast cells. Tachyphylaxis was observed with both drugs. The 2 compounds were extremely selective in their action, being less active against peritoneal mast cells from the hamster and completely ineffective against mast cells from the mouse. Human basophil leucocytes, tissue mast cells of the guinea-pig and rat intestinal mast cells were also unresponsive. Both drugs inhibited immunological histamine release from human pulmonary mast cells obtained by bronchoalveolar lavage (BAL) and, less effectively, from lung parenchyma. Nedocromil sodium was about 1 order of magnitude more potent than sodium cromoglycate in each case. Tachyphylaxis was observed with the dispersed lung, but not with the cells obtained by BAL, and the degree of inhibition varied inversely with the magnitude of the secretory response. The possible clinical significance of these observations is discussed.


Asunto(s)
Antiinflamatorios no Esteroideos/farmacología , Cromolin Sódico/farmacología , Liberación de Histamina/efectos de los fármacos , Mastocitos/metabolismo , Quinolonas/farmacología , Animales , Cricetinae , Humanos , Técnicas In Vitro , Pulmón/citología , Masculino , Mastocitos/efectos de los fármacos , Mesocricetus , Ratones , Nedocromil , Nippostrongylus/inmunología , Peritoneo/citología , Ratas , Ratas Endogámicas
8.
Diagn Microbiol Infect Dis ; 16(3): 205-13, 1993.
Artículo en Inglés | MEDLINE | ID: mdl-8477574

RESUMEN

A total of 2189 staphylococcal strains at the University of Iowa Hospitals and Clinics (Iowa City, IA) were initially screened to determine the incidence of constitutive (29.8%) and potential inducible macrolide-lincosamide-streptogramin (MLS) resistance (11.3%). Staphylococcus haemolyticus and S. epidermidis (62.5% and 55.3%) showed the highest incidence of constitutive resistance. Staphylococcus hominis had the highest incidence of inducible resistance (40.6%), while S. aureus had the lowest rate for both resistance types. The overall ratio of constitutive-inducible MLS resistance was 4:1. Among strains initially speciated using the Vitek System GPI card, there was only a 69% species identification reproducibility, and 78% accuracy versus a reference identification method. A random sample of 105 Staphylococcus spp. isolates with discordant macrolide (erythromycin resistant) and lincosamide (clindamycin susceptible) susceptibility patterns were tested against 16 antimicrobial agents by using a reference broth microdilution method. All erythromycin-resistant Staphylococcus spp. were also resistant to other 14-member macrolides and azithromycin, while all organisms remained susceptible to clindamycin, rifampin, vancomycin, and the streptogramin compounds (RP59500 and virginiamycin). Resistance to teicoplanin was identified among some oxacillin-resistant S. haemolyticus strains. Of 105 isolates, 65 (62%) showed inducible MLS resistance, 28 (27%) were noninducible, and 12 (11%) were either fully susceptible or resistant to the MLS drugs (Vitek System interpretation errors). MLS disk induction tests revealed two inducible resistance phenotypes: ML and MLS. Staphylococcus aureus showed the highest inducible resistance rate at 95% with an MLS-predominant pattern. In contrast, endemic S. haemolyticus isolates did not demonstrate inducible resistance that is, efflux-mediated erythromycin resistance.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Antibacterianos/farmacología , Quimioterapia Combinada/farmacología , Macrólidos , Staphylococcus/efectos de los fármacos , Virginiamicina/farmacología , Farmacorresistencia Microbiana , Lincosamidas , Pruebas de Sensibilidad Microbiana , Staphylococcus/clasificación , Staphylococcus/aislamiento & purificación
9.
Diagn Microbiol Infect Dis ; 14(2): 111-8, 1991.
Artículo en Inglés | MEDLINE | ID: mdl-1873969

RESUMEN

This multicenter study was designed to compare the new BACTEC PLUS system (nonradiometric), which utilizes an 8- to 10-ml blood inoculum in a resin-containing medium, to the standard BACTEC (nonradiometric) without resins and 5-ml blood inoculum. There were 12,341 compliant sets studied, yielding 1331 positives, with 1099 sets deemed clinically significant. Overall the BACTEC PLUS showed an enhanced recovery of 33% (p less than 0.001) over its standard counterpart, with significant yield increased in the staphylococci (p less than 0.001), streptococci (p less than 0.002), pseudomonads (p less than 0.002), Enterobacteriaceae (p less than 0.001), and other aerobic Gram negatives (p less than 0.02). The enhanced performance increased to 53% if the patient was receiving any antibiotics at the time the blood was cultured. In patients known to be free of antibiotics at the time of blood draw, there was still an increased yield of 18%. The new system detected positivity at least one reading sooner than twice as often as the converse, and confirmed septic episodes significantly more often (21% overall) (41% on antibiotics) (15% no antibiotics). The BACTEC PLUS has distinct advantages over its low blood volume, nonresin counterpart.


Asunto(s)
Bacterias/aislamiento & purificación , Técnicas Bacteriológicas , Sepsis/diagnóstico , Enterobacteriaceae/aislamiento & purificación , Bacterias Gramnegativas/aislamiento & purificación , Bacterias Grampositivas/aislamiento & purificación , Humanos , Pseudomonas/aislamiento & purificación , Sepsis/microbiología , Staphylococcus/aislamiento & purificación , Streptococcus/aislamiento & purificación , Levaduras/aislamiento & purificación
10.
Clin Ther ; 19(4): 642-55, 1997.
Artículo en Inglés | MEDLINE | ID: mdl-9377610

RESUMEN

The efficacy and safety of Naprelan (naproxen sodium) 1000 mg once daily (QD) and nabumetone 1500 mg QD were compared in a multicenter, randomized, parallel-group, placebo-controlled, double-masked, 4-week study of adult outpatients with active osteoarthritis (OA) of the knee. Nabumetone 1500 mg was chosen for comparison because it is commonly prescribed in a QD dosing regimen for OA. After a washout period free of nonsteroidal anti-inflammatory drugs, 279 patients were enrolled and assigned randomly to treatment with either Naprelan 1000 mg QD (n = 92), nabumetone 1500 mg QD (n = 93), or placebo (n = 94). All treatments were evaluated for efficacy and safety at baseline and at weeks 2 and 4 of the treatment period or at discontinuation. Demographic characteristics were comparable among all treatment groups. As might be expected in a study of OA of the knee, a majority of patients enrolled were women (68.8%), and many were obese (mean weight, 195.6 lb; mean height, 66 in). Significantly fewer patients (13) treated with Naprelan prematurely discontinued the study than did patients treated with placebo (27); there was a lower rate of discontinuation for insufficient therapeutic effect in the Naprelan group compared with the nabumetone and placebo groups. Using an intent-to-treat model, the overall distribution of scores in all three primary efficacy assessments (investigator's global assessment of OA, patient's global assessment of OA, and walking pain) at week 2 and at the last visit was significantly better for the Naprelan group compared with both the nabumetone and placebo groups. The mean improvement from baseline was also significant for Naprelan compared with the nabumetone and placebo groups for all three assessments at week 2 and for investigator's global assessment of OA and walking pain at the last visit. The nabumetone-treated group showed significant improvement over the placebo-treated group in only one primary assessment: mean change from baseline in patient's global assessment of OA at week 2. At week 2, significant differences favoring Naprelan versus nabumetone and placebo were measured in overall distribution of scores for joint tenderness and nighttime pain. Distribution of quality of sleep and inactivity stiffness scores also improved relative to placebo at week 2. At the last visit, nighttime pain scores were still significantly better for patients receiving Naprelan versus nabumetone and placebo. Patients receiving nabumetone had statistically significant improvement from baseline in inactivity stiffness compared with placebo at week 2. There were no clinically important differences among treatment groups in the occurrence of adverse events or laboratory abnormalities. The results of this 4-week study of Naprelan 1000 mg QD compared with nabumetone 1500 mg QD demonstrate at least equal efficacy (superior efficacy was demonstrated for several parameters) and equal safety in adult outpatients with active OA of the knee.


Asunto(s)
Antiinflamatorios no Esteroideos/uso terapéutico , Butanonas/uso terapéutico , Naproxeno/uso terapéutico , Osteoartritis/tratamiento farmacológico , Adulto , Anciano , Antiinflamatorios no Esteroideos/efectos adversos , Butanonas/efectos adversos , Preparaciones de Acción Retardada , Método Doble Ciego , Femenino , Humanos , Masculino , Persona de Mediana Edad , Nabumetona , Naproxeno/efectos adversos , Resultado del Tratamiento
11.
Clin Exp Rheumatol ; 8(6): 583-6, 1990.
Artículo en Inglés | MEDLINE | ID: mdl-2289328

RESUMEN

Four rheumatologists and 2 radiologists utilized 3 reading techniques to evaluate clinical radiographic progression in selected serial hand and wrist films from 5 rheumatoid arthritis patients. The carpometacarpal radio determinations were the most internally consistent; global assessment and total erosion + joint space narrowing scores showed the best between-method correlations; and the erosion + joint space narrowing scores depicted most sensitively the progression over time which was not affected by immunomodulating agent or non-steroidal anti-inflammatory agent therapy. In this study, instructed, non-experienced readers detected rheumatoid radiographic progression utilizing readily available scoring techniques.


Asunto(s)
Artritis Reumatoide/diagnóstico por imagen , Artritis Reumatoide/tratamiento farmacológico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Radiografía , Tecnología Radiológica
12.
Mutat Res ; 150(1-2): 443-50, 1985.
Artículo en Inglés | MEDLINE | ID: mdl-4000168

RESUMEN

The cytotoxic and mutagenic effect of X-irradiation was determined with Chinese hamster ovary cells arrested in the G0/G1 phase of the cell cycle through 9 days incubation in serum-free medium. In comparison with exponential phase cultures, the arrested cells showed increased cytotoxicity and mutation induction over the dose range of 50-800 rad. Exponential cultures showed a linear mutant frequency-survival relationship while the arrested cells showed a biphasic linear relationship. A post irradiation holding period of 24 h does not result in any change in the mutant frequency. The increased sensitivity of the arrested cells to the mutagenic effects of X-rays appears to be a cell-cycle phase phenomenon. Upon readdition of serum, the arrested cells re-enter the cell cycle in a synchronous manner, reaching S phase at 10-12 h. Cells irradiated at 5 h after serum addition, i.e. in G1, show a similar dose response for mutant frequency, while those irradiated at 10 h or later, i.e. in late G1, S or G2, show lower mutation induction. These observations are consistent with a chromosome interchange mechanism of mutation induction by X-rays, possibly through interactions between repairing regions of the DNA. Irradiation of cells in the G0/G1 phase allow more time for such interactions in the absence of semiconservative DNA replication.


Asunto(s)
Hipoxantina Fosforribosiltransferasa/genética , Interfase , Mutación/efectos de la radiación , Animales , Ciclo Celular , Línea Celular , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/efectos de la radiación , Cricetinae , Cricetulus , Medios de Cultivo , Resistencia a Medicamentos , Femenino , Ovario , Tioguanina/toxicidad , Rayos X
13.
Phytopathology ; 87(5): 565-71, 1997 May.
Artículo en Inglés | MEDLINE | ID: mdl-18945113

RESUMEN

ABSTRACT The identity of a Puccinia species occurring on the introduced weed dyer's woad (Isatis tinctoria) was studied using sequences from the internal transcribed spacer of the nuclear ribosomal DNA. The relationship of this fungus to other Puccinia species occurring on the family Brassicaceae in Europe and North America was examined, and we tested the hypothesis that P. thlaspeos and P. monoica are correlated species. The data suggest that the Puccinia species from dyer's woad is closely related to the North American species P. consimilis and may be derived from an indigenous strain of P. consimilis that switched hosts. Thus, the Puccinia species from dyer's woad is probably native to North America and is unlikely to cause disease epidemics on indigenous plants if used as a biological control agent against dyer's woad. P. thlaspeos appears to be polyphyletic and, therefore, P. thlaspeos and P. monoica do not appear to be correlated species. Additional DNA sequence data will be needed to clarify further the phylogeny of Puccinia species on the family Brassicaceae.

14.
J Sch Health ; 69(5): 171-6, 1999 May.
Artículo en Inglés | MEDLINE | ID: mdl-10363220

RESUMEN

The obligation to obtain informed consent for student participation in health-related research creates a complex set of legal, ethical, and administrative responsibilities because the interests of research integrity are delicately balanced against protection of human subjects. Even the term itself sparks a range of responses depending on one's perspective and stake in the process. This paper traces the historical impetus behind obtaining informed consent, identifies key elements comprising informed consent, and reviews types of consent procedures used in schools. The authors suggest 20 ways to boost response rates while providing a realistic level of informed consent for school-based studies.


Asunto(s)
Investigación Conductal , Consentimiento Informado , Relaciones Padres-Hijo , Consentimiento Paterno , Investigación , Instituciones Académicas , Adolescente , Niño , Revelación , Ética Médica , Gobierno Federal , Regulación Gubernamental , Experimentación Humana/legislación & jurisprudencia , Humanos , Consentimiento Informado/legislación & jurisprudencia , Privacidad/legislación & jurisprudencia , Medición de Riesgo , Estados Unidos
18.
Microbiol Res ; 164(2): 212-20, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-17418553

RESUMEN

The aim of this study was to investigate the impact on numbers of using different media for the enumeration of Escherichia coli subjected to stress, and to evaluate the use of different resuscitation methods on bacterial numbers. E. coli was subjected to heat stress by exposure to 55 degrees C for 1h or to light-induced oxidative stress by exposure to artificial light for up to 8h in the presence of methylene blue. In both cases, the bacterial counts on selective media were below the limits of detection whereas on non-selective media colonies were still produced. After resuscitation in non-selective media, using a multi-well MPN resuscitation method or resuscitation on membrane filters, the bacterial counts on selective media matched those on non-selective media. Heat and light stress can affect the ability of E. coli to grow on selective media essential for the enumeration as indicator bacteria. A resuscitation method is essential for the recovery of these stressed bacteria in order to avoid underestimation of indicator bacteria numbers in water. There was no difference in resuscitation efficiency using the membrane filter and multi-well MPN methods. This study emphasises the need to use a resuscitation method if the numbers of indicator bacteria in water samples are not to be underestimated. False-negative results in the analysis of drinking water or natural bathing waters could have profound health effects.


Asunto(s)
Recuento de Colonia Microbiana/métodos , Escherichia coli K12/metabolismo , Viabilidad Microbiana , Estrés Oxidativo , Microbiología del Agua , Medios de Cultivo/metabolismo , Escherichia coli K12/crecimiento & desarrollo , Escherichia coli K12/efectos de la radiación , Luz
19.
Soc Hist Med ; 14(2): 199-221, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11688503

RESUMEN

The licensing of African healers in the province of Natal, South Africa combined with urbanization, medical commodification, and an overcrowded biomedical market led to ideological and commercial competition between White biomedical practitioners and African healers in the early twentieth century in southeastern Africa. This article examines the historical antecedents of this competition and focuses on the role that competition, race, and gender played in the construction of local biomedical and African ideas of medical authority. Adopting the idea that medicine is an important site of power, contestation, and cultural exchange, I aim not only to document these historical changes in African therapeutics, but to problematize current ideas of biomedicine's colonial hegemony.


Asunto(s)
Competencia Económica/historia , Médicos/historia , Grupos Raciales/historia , Historia del Siglo XX , Humanos , Poder Psicológico , Sudáfrica
20.
J Appl Bacteriol ; 63(3): 261-70, 1987 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-3323155

RESUMEN

Escherichia coli introduced into autoclaved filtered river water survived for up to 260 d at temperatures from 4 degrees to 25 degrees C with no loss of viability. Survival times were less in water which was only filtered through either a Whatman filter paper or a 0.45 micron Millipore filter or in untreated water, suggesting that competition with the natural microbial flora of the water was the primary factor in the disappearance of the introduced bacteria. Survival was also dependent upon temperature with survival at 4 degrees C greater than 15 degrees C greater than 25 degrees C greater than 37 degrees C for any water sample. Direct counts showed that bacterial cells did not disappear as the viable count decreased. The possession of the antibiotic resistance plasmids, R1drd-19 or R144-3, did not enhance survival nor cause a faster rate of decay, indicating that the metabolic burden imposed by a plasmid was not a factor in survival under starvation conditions. There was no evidence of transfer of either plasmid at 15 degrees C or of loss of plasmid function during starvation.


Asunto(s)
Escherichia coli/crecimiento & desarrollo , Microbiología del Agua , Escherichia coli/genética , Filtración , Agua Dulce , Plásmidos , Temperatura
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