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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.
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
5.
Lett Appl Microbiol ; 37(5): 380-5, 2003.
Artículo en Inglés | MEDLINE | ID: mdl-14633108

RESUMEN

AIMS: The aim of this study was to investigate the links between survival of Escherichia coli in sea water microcosms in the laboratory and the presence of porins in the outer membrane. The E. coli strains studied were a wild-type strain and a series of outer membrane protein (omp) mutants. METHODS AND RESULTS: Bacteria were suspended in natural or filtered-autoclaved sea water microcosms and numbers determined over an incubation period by plate count and by count of cells capable of respiration. CONCLUSIONS: The type of omp mutation has a significant impact in bacterial survival. The double OmpC-OmpF mutant and the OmpR mutant (which was incapable of synthesizing OmpC and OmpF) survived poorly compared with single omp mutants and the wild-type strain. This suggests that these proteins are important in determining the entry of E. coli into the survival mode. The EnvZ mutant, which lacks the protein by which the cell senses some changes in the environment, survived as well as the wild-type strain when compared by plate counts and by respiring cell count. The loss of the EnvZ protein has no effect on survival but it could prevent the organism sensing the changes in the environment through which entry into the survival state is triggered. SIGNIFICANCE AND IMPACT OF THE STUDY: This work is another piece in the puzzle as to how bacteria survive stress conditions.


Asunto(s)
Escherichia coli/fisiología , Porinas/metabolismo , Agua de Mar/microbiología , Proteínas de la Membrana Bacteriana Externa/metabolismo , Escherichia coli/crecimiento & desarrollo , Escherichia coli/metabolismo , Mutación , Porinas/deficiencia , Porinas/genética
6.
Lett Appl Microbiol ; 35(6): 533-7, 2002.
Artículo en Inglés | MEDLINE | ID: mdl-12460439

RESUMEN

AIMS: The aim was to identify changes in outer membrane proteins (omps), OmpA, OmpC and OmpF, in Escherichia coli under starvation conditions in lake water microcosms studied at different temperatures. METHODS AND RESULTS: Escherichia coli was incubated in lake water microcosms at a variety of temperatures and the omps studied using quantitative densitometric analysis of protein bands of sodium dodecyl sulphate gels of omp preparations. The amount of OmpF increased over the incubation period relative to that of OmpC whereas the relative abundance of OmpA declined, most notably at 25 and 37 degrees C. This change was linked to changes in peak cell volume as determined by cell measurements. CONCLUSIONS: Major changes to the omps of E. coli accompany the adaptation of the organism to starvation conditions in lake water microcosms. SIGNIFICANCE AND IMPACT OF THE STUDY: Prolonged starvation affects the relative amounts of outer membrane porins. This study furthers the understanding of the role played by changes in the omp composition in E. coli during survival in lake water environments.


Asunto(s)
Proteínas de Escherichia coli/metabolismo , Escherichia coli/fisiología , Agua Dulce/microbiología , Regulación Bacteriana de la Expresión Génica , Respuesta al Choque Térmico , Porinas/metabolismo , Proteínas de la Membrana Bacteriana Externa/metabolismo , Ecosistema , Escherichia coli/crecimiento & desarrollo , Escherichia coli/metabolismo , Temperatura
7.
J Environ Monit ; 4(2): 229-34, 2002 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11993761

RESUMEN

Water samples have been extracted from inside (from standpipes) and from outside (from boreholes) of the trenches at the low level radioactive waste disposal site at Drigg in Cumbria, UK. The samples were taken anaerobically from between 8.5 and 10.0 m below the surface using a submersible pump at low flow rates to ensure that the waters in the standpipes and boreholes were maintained at constant levels. To ensure representative samples, the Eh, pH. conductivity, temperature, iron and dissolved oxygen concentrations of the waters were taken during initial purging and during sampling. The gross tritium, gross non-tritium beta, gross alpha and gamma activities of each sample were determined using suitable sample preparation and counting techniques. Samples were then anaerobically, sequentially filtered through 12 microm, 1 microm, 30 kDa and 500 Da filter membranes. The filtrates were analysed for gross alpha, gross non-tritium beta and gamma activities. SEM and STEM analyses were used to determine the colloid population. An energy dispersive analyser on the SEM was used to determine the major elements present in the colloids. UV-visible spectrophotometry, fluorescence spectrophotometry and high performance size exclusion liquid chromatography were used to analyse the waters before and after treatment with ion exchange materials to determine whether natural organic matter was present in the waters. Results showed that two major types of colloids (iron containing colloids and silicon containing colloids) were present in the waters. There were also a small number of other colloids that contain, as major elements, aluminium, calcium and chromium. Organic colloids were also present. The majority of the radioactivity in the waters was due to tritium. Waters taken from outside the trenches contained low levels of non-tritium beta activities and alpha activities which were lower than the minimum detectable amount. Waters taken from the trenches contained non-tritium beta activities and low levels of alpha emitters. Filtration of the trench waters showed that some of the alpha activity was retained by the 30 kDa and 500 Da membranes suggesting that this activity was associated with small colloids. Radioactivity was not found to be associated with colloids present in the waters taken from outside the trenches. Possible reasons for this observation could be that radionuclide bearing colloids have not yet reached the far-field or that the radionuclide concentration is diluted to below the minimum detectable amount. After concentrating two of the samples by factors of x20 and x 16 respectively, 2.4+/-0.1 and 0.6+/-0.1 Bq dm(-3) of 137Cs were measured.


Asunto(s)
Coloides/análisis , Metales Pesados/análisis , Residuos Radiactivos , Inglaterra , Monitoreo del Ambiente , Concentración de Iones de Hidrógeno , Espectrofotometría , Temperatura , Administración de Residuos
8.
J Appl Microbiol ; 92(6): 1097-104, 2002.
Artículo en Inglés | MEDLINE | ID: mdl-12010550

RESUMEN

AIMS: To study the relationship between changes in the composition of the outer membrane proteins and the survival of Salmonella typhimurium LT2 in filtered autoclaved seawater containing Toluidine Blue (TB) dye as a photosensitizer. METHODS AND RESULTS: In samples exposed to TB and excited by artificial visible light, the total viable (TVC) and respiring cell counts (RCC) showed that, although the TVC declined to an undetectable level in 6.5 h, the RCC showed that some cells were still capable of respiration. The porin protein composition changed gradually with OmpC and OmpF becoming undetectable by sodium dodecyl sulphate-polyacrylamide gel electrophoresis after 8 h of incubation. Hydrogen peroxide-pretreated cells survived longer compared with the control. CONCLUSIONS: Oxidative pretreatment of Salm. typhimurium protects cells from some of the effects of sunlight in the presence of photosensitizers. The changes in porin proteins may play a role in this protection. SIGNIFICANCE AND IMPACT OF THE STUDY: The study shows that the survival of bacteria under conditions of stress is the result of a linked series of reactions.


Asunto(s)
Colorantes/farmacología , Porinas/análisis , Salmonella typhimurium/efectos de los fármacos , Salmonella typhimurium/crecimiento & desarrollo , Cloruro de Tolonio/farmacología , Proteínas de la Membrana Bacteriana Externa/análisis , Recuento de Colonia Microbiana , Peróxido de Hidrógeno/farmacología , Oxidantes/farmacología , Estrés Oxidativo , Fármacos Fotosensibilizantes/farmacología , Salmonella typhimurium/química , Agua de Mar/microbiología
9.
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
11.
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
12.
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
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 Appl Microbiol ; 82(3): 301-9, 1997 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-12455893

RESUMEN

Survival, electron transport system (ETS) activity and the activity of NADH and succinate dehydrogenase of Escherichia coli ML30 were studied under starvation stress at different temperatures in a filtered-autoclaved lake water microcosm. ETS activity in E. coli declined rapidly at 30 degrees C but more slowly at 4 degrees and 15 degrees C over a 20 d starvation period. The decrease in ETS activity in E. coli only started after 6 d of incubation at 4 degrees C and 15 degrees C. Viability of E. coli, as determined by plate counts, declined faster at 37 degrees C than at the other temperatures and remained highest at 4 degrees C in filtered-autoclaved lake water. There was also a significant cell size reduction at 37 degrees C in filtered-autoclaved lake water but not at 4 degrees C. ETS activity after up to 16 d of starvation increased after the addition of nutrient broth to the filtered-autoclaved lake water at 15 degrees C and 30 degrees C suggesting that cells were still able to respond to nutrients, even after prolonged starvation. The response to the addition of nutrient broth, however, declined with the length of the starvation period. The activity of both succinate and NADH dehydrogenase declined over a 13 d starvation period. The loss of activity was fastest at 37 degrees C compared to lower incubation temperatures but even at 4 degrees C, a significant proportion of the activity was lost over the 13 d period.


Asunto(s)
Escherichia coli/enzimología , Inanición/enzimología , Microbiología del Agua , Recuento de Colonia Microbiana , Transporte de Electrón , Escherichia coli/fisiología , Agua Dulce/microbiología , NADH Deshidrogenasa/metabolismo , Esterilización , Succinato Deshidrogenasa/metabolismo , Temperatura
15.
J Appl Bacteriol ; 80(3): 252-8, 1996 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-8852672

RESUMEN

Escherichia coli grown in high or low phosphate medium was inoculated into a lake water starvation medium. The viable count decreased at 37 degrees C but not at the lower temperatures over 70 d. Alkaline phosphatase was monitored using a colorimetric assay with pNPP as the substrate. Derepression of the enzyme occurred in cultures starved for > 30 d in the lake water and within 5 d in lake water microcosms supplemented with carbon and nitrogen sources where there was rarely an increase in viable count. Chloramphenicol prevented the synthesis of alkaline phosphatase suggesting that, even under starvation conditions, de novo synthesis of the enzyme occurs.


Asunto(s)
Fosfatasa Alcalina/metabolismo , Escherichia coli/enzimología , Microbiología del Agua , Aminoácidos/metabolismo , Carbono/metabolismo , Cloranfenicol/farmacología , Medios de Cultivo , Escherichia coli/efectos de los fármacos , Escherichia coli/crecimiento & desarrollo , Microclima , Fosfatos/metabolismo , Inhibidores de la Síntesis de la Proteína/farmacología , Temperatura
16.
Lett Appl Microbiol ; 21(6): 364-7, 1995 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-8554763

RESUMEN

Escherichia coli was heat stressed at 55 degrees, 60 degrees or 65 degrees C in sterile flasks of lake water. After 6 h at these temperatures the viable count on nutrient agar had dropped below the limits of detection (1 colony in 100 ml). The flasks were transferred to a 15 degrees C incubator and left for 7 d. Recovery of the stressed E. coli was shown to occur within 48 h at this temperature. Recovery also occurred in microcosms amended with 5% (v/v) synthetic sewage. The stressed E. coli multiplied in the amended but not in the unamended microcosms.


Asunto(s)
Escherichia coli/crecimiento & desarrollo , Agua Dulce , Calor , Microbiología del Agua , Ecosistema , Aguas del Alcantarillado
18.
J Clin Microbiol ; 33(9): 2451-3, 1995 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-7494044

RESUMEN

The BACTEC 9240 blood culture system (Becton Dickinson Diagnostic Instrument Systems, Sparks, Md.) is one of three automated, continuous-monitoring systems that is widely used in clinical laboratories. The BACTEC 9240 was compared with the BACTEC NR 660 for the detection of organisms and bacteremic episodes; time to detection of positive cultures; number of false-positive and false-negative cultures; and time needed to load, process, and perform quality control functions by using high-volume aerobic media. Blood specimens (5,282) were inoculated in equal volumes (5 to 10 ml per bottle) into BACTEC Plus Aerobic/F (9240 system) and BACTEC Plus NR26 (660 system) bottles. Clinically significant isolates were detected in 6.6% of cultures, representing 348 microorganisms and 216 bacteremic episodes. Two hundred forty-eight microorganisms were detected by both systems, 48 by the 9240 only and 52 by the 660 only (P = not significant). Of the bacteremic episodes, 158 were detected by both systems, 27 by the 9240 only and 31 by the 660 only (P = not significant). Analysis of data by month revealed equivalent recovery rates for both systems, with the exception of a 30-day period at one study site during which the 660 system detected significantly more microorganisms. Following a proprietary hardware design retrofit of the 9240 instrument, detection rates were again equivalent for the remaining three months at this study site. Positive cultures detected by both systems were detected an average of 4.3 h faster by the 9240 system (21 versus 25.3 h). The numbers of false-positive cultures for the 9240 and 660 systems were 40 (1.0%) and 9 ( < 1.0%), respectively. The numbers of false-negative cultures were five for the 9240 system and three for the 660 system. The 9240 system required 23 s less technologist time per bottle to operate during the 5-day protocol. In conclusion, the BACTEC 9240 used with high-volume Aerobic/F medium is equivalent to the BACTEC 660 used with high volume NR26 medium for the detection of microorganisms and bacteremic episodes. In addition, the 9240 system detects positive cultures more rapidly than the 660 system but requires further evaluation to ensure reliability of instrument components.


Asunto(s)
Técnicas Bacteriológicas/instrumentación , Automatización , Medios de Cultivo , Estudios de Evaluación como Asunto
19.
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
20.
Cell ; 78(5): 799-811, 1994 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-8087847

RESUMEN

The transcription factor E2F is regulated through its cyclical interaction with a spectrum of cellular proteins. One such protein is the product of the retinoblastoma gene (Rb); association of E2F with Rb inhibits its transactivation potential. However, in adenovirus-infected cells, E2F is complexed to the 19 kDa product of the adenovirus E4 gene. We have studied the interaction of E2F-1 with the Rb and adenovirus E4 proteins and show that phosphorylation of E2F-1 on serine residues 332 and 337 prevented its interaction with Rb but was a prerequisite for interaction with E4. These residues were phosphorylated in vivo and by p34cdc2 kinase in vitro. Upon stimulation of serum-starved cells, phosphorylation was induced in the late G1 phase of the cell cycle. These observations suggest that phosphorylation of E2F-1 is important in the regulation of its activity during the cell cycle and during infection of cells by adenovirus.


Asunto(s)
Proteínas E4 de Adenovirus/metabolismo , Proteínas Portadoras , Proteínas de Ciclo Celular , Proteínas de Unión al ADN , Proteína de Retinoblastoma/metabolismo , Factores de Transcripción/metabolismo , Infecciones por Adenoviridae/metabolismo , Secuencia de Aminoácidos , Proteína Quinasa CDC2/metabolismo , Ciclo Celular/fisiología , Ciclinas/metabolismo , Factores de Transcripción E2F , Factor de Transcripción E2F1 , Datos de Secuencia Molecular , Fosforilación , Unión Proteica , Proteínas Quinasas/metabolismo , Proteína 1 de Unión a Retinoblastoma , Serina/metabolismo
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