RESUMEN
Increasing energy costs and environmental concerns have emphasized the need to produce sustainable renewable fuels and chemicals. Major efforts to this end are focused on the microbial production of high-energy fuels by cost-effective 'consolidated bioprocesses'. Fatty acids are composed of long alkyl chains and represent nature's 'petroleum', being a primary metabolite used by cells for both chemical and energy storage functions. These energy-rich molecules are today isolated from plant and animal oils for a diverse set of products ranging from fuels to oleochemicals. A more scalable, controllable and economic route to this important class of chemicals would be through the microbial conversion of renewable feedstocks, such as biomass-derived carbohydrates. Here we demonstrate the engineering of Escherichia coli to produce structurally tailored fatty esters (biodiesel), fatty alcohols, and waxes directly from simple sugars. Furthermore, we show engineering of the biodiesel-producing cells to express hemicellulases, a step towards producing these compounds directly from hemicellulose, a major component of plant-derived biomass.
Asunto(s)
Biocombustibles/microbiología , Biomasa , Escherichia coli/genética , Escherichia coli/metabolismo , Ácidos Grasos/biosíntesis , Plantas/metabolismo , Alcoholes Grasos/metabolismo , Ingeniería Genética , Operón/genética , Polisacáridos/metabolismo , Xilanos/metabolismoRESUMEN
OBJECTIVES: To determine the impact of traumatic brain injury (TBI) on female menstrual and reproductive functioning and to examine the relationships between severity of injury, duration of amenorrhea, and TBI outcomes. DESIGN: Retrospective cohort survey. SETTING: Telephone interview. PARTICIPANTS: Women (N=30; age range, 18-45y), between 1 and 3 years postinjury, who had completed inpatient rehabilitation for TBI. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Data collected included menstrual and reproductive functioning pre- and postinjury, demographic, and injury characteristics. Outcome measures included the Glasgow Outcome Scale-Extended (GOS-E), the Mayo-Portland Adaptability Inventory-4 (MPAI-4), and the Medical Outcome Study 12-Item Short-Form Health Survey, Version 2 (SF-12v2). RESULTS: The median duration of amenorrhea was 61 days (range, 20-344d). Many subjects' menstrual function changed after TBI, reporting a significant increase in skipped menses postinjury (P<.001) and a trend toward more painful menses (P=.061). More severe TBI, as measured by the duration of posttraumatic amnesia, was significantly predictive of a longer duration of amenorrhea (P=.004). Subjects with a shorter duration of amenorrhea scored significantly better on the SF-12 physical component subscale (P=.004), the GOS-E (P=.05), and the MPAI-4 participation subscale (P=.05) after controlling for age, injury severity, and time postinjury. CONCLUSIONS: The severity of TBI was predictive of duration of amenorrhea and a shorter duration of amenorrhea was predictive of better ratings of global outcome, community participation, and health-related quality of life postinjury.
Asunto(s)
Amenorrea/etiología , Lesiones Encefálicas/complicaciones , Adolescente , Adulto , Estudios de Cohortes , Dismenorrea/etiología , Femenino , Humanos , Puntaje de Gravedad del Traumatismo , Persona de Mediana Edad , Modelos de Riesgos Proporcionales , Estudios RetrospectivosRESUMEN
OBJECTIVE: To investigate whether intermittent catheterization (IC) with a hydrophilic-coated catheter delays the onset of the first symptomatic urinary tract infection (UTI) and reduces the number of symptomatic UTIs in patients with acute spinal cord injury (SCI) compared with IC with standard, uncoated catheters. DESIGN: A prospective, randomized, parallel-group trial. SETTING: Fifteen North American SCI centers. Participants were followed up while in the hospital or rehabilitation unit (institutional period) and up to 3 months after institutional discharge (community period). The maximal study period was 6 months. PARTICIPANTS: A total of 224 subjects with traumatic SCI of less than 3 months' duration who use IC. METHODS: The participants were randomized within 10 days of starting IC to either single-use hydrophilic-coated (SpeediCath) or polyvinyl chloride uncoated (Conveen) catheters. MAIN OUTCOME MEASUREMENTS: The time from the first catheterization to the first antibiotic-treated symptomatic UTI was measured as well as the total number of symptomatic UTIs during the study period. RESULTS: The time to the first antibiotic-treated symptomatic UTI was significantly delayed in the hydrophilic-coated catheter group compared with the uncoated catheter group. The delay corresponded to a 33% decrease in the daily risk of developing the first symptomatic UTI among participants who used the hydrophilic-coated catheter. In the institutional period, the incidence of antibiotic-treated symptomatic UTIs was reduced by 21% (P < .05) in the hydrophilic-coated catheter group. CONCLUSIONS: The use of a hydrophilic-coated catheter for IC is associated with a delay in the onset of the first antibiotic-treated symptomatic UTI and with a reduction in the incidence of symptomatic UTI in patients with acute SCI during the acute inpatient rehabilitation. Using a hydrophilic-coated catheter could minimize UTI-related complications, treatment costs, and rehabilitation delays in this group of patients, and reduce the emergence of antibiotic-resistant organisms.