Using Double Negative Controls to Adjust for Healthy User Bias in a Recombinant Zoster Vaccine Safety Study.

Unmeasured confounding is a major concern in many epidemiologic studies that are not randomized. Negative control methods can detect and reduce confounding by leveraging the proxies of the unmeasured confounders, including negative control outcomes (NCO) and exposures (NCE). An NCO is presumably unaffected by the exposure of interest but would be associated with unmeasured confounders; an NCE presumably does not affect the outcome of interest but would be associated with unmeasured confounders.

Challenges in Heart Failure Disease Management in Skilled Nursing Facilities: A Qualitative Study.

Clinical guidelines recommend clinicians in skilled nursing facilities (SNFs) monitor body weight and signs and symptoms related to heart failure (HF) and encourage a sodium restricted diet to improve HF outcomes; however, SNFs face considerable challenges in HF disease management (HF-DM). In the current study, we characterized the challenges of HF-DM with data from semi-structured, in-depth interviews with patients, caregivers, staff, and physicians from nine SNFs. Patients receiving skilled nursing care were interviewed together as a dyad with their caregiver.

Distinct carbon isotope fractionation during anaerobic degradation of dichlorobenzene isomers.

Chlorinated benzenes are ubiquitous organic contaminants found in groundwater and soils. Compound specific isotope analysis (CSIA) has been increasingly used to assess natural attenuation of chlorinated contaminants, in which anaerobic reductive dechlorination plays an essential role. In this work, carbon isotope fractionation of the three dichlorobenzene (DCB) isomers was investigated during anaerobic reductive dehalogenation in methanogenic laboratory microcosms.

Dehalogenation of chlorobenzenes, dichlorotoluenes, and tetrachloroethene by three Dehalobacter spp.

Three enrichment cultures containing Dehalobacter spp. were developed that dehalogenate each of the dichlorobenzene (DCB) isomers to monochlorobenzene (MCB), and the strains using 1,2-DCB (12DCB1) or 1,3-DCB (13DCB1) are now considered isolated, whereas the strain using 1,4-DCB (14DCB1) is considered highly enriched. In this study, we examined the dehalogenation capability of each strain to use chlorobenzenes with three or more chlorines, tetrachloroethene (PCE), or dichlorotoluene (DCT) isomers.

Airway obstruction due to unilateral vocal fold paralysis.

Objectives/hypothesis: Airway obstruction is an uncommon presentation of unilateral laryngeal paralysis. We have observed two mechanisms of obstruction: arytenoid prolapse and inappropriate adduction of the paralyzed vocal fold. We evaluated arytenoid abduction (AAb) and recurrent laryngeal nerve (RLN) reinnervation as treatments for airway obstruction in patients with unilateral laryngeal paralysis.

Pathway-dependent isotope fractionation during aerobic and anaerobic degradation of monochlorobenzene and 1,2,4-trichlorobenzene.

Stable carbon isotope fractionation is a valuable tool for monitoring natural attenuation and to establish the fate of groundwater contaminants. In this study, we measured carbon isotope fractionation during aerobic and anaerobic degradation of two chlorinated benzenes: monochlorobenzene (MCB) and 1,2,4-trichlorobenzene (1,2,4-TCB). MCB isotope fractionation was measured in anaerobic methanogenic microcosms, while 1,2,4-TCB isotope experiments were carried out in both aerobic and anaerobic microcosms.

A role for Dehalobacter spp. in the reductive dehalogenation of dichlorobenzenes and monochlorobenzene.

Previously, we demonstrated the reductive dehalogenation of dichlorobenzene (DCB) isomers to monochlorobenzene (MCB), and MCB to benzene in sediment microcosms derived from a chlorobenzene-contaminated site. In this study, enrichment cultures were established for each DCB isomer and each produced MCB and trace amounts of benzene as end products. MCB dehalogenation activity could only be transferred in sediment microcosms.

Using NMR metabolomics to investigate tricarboxylic acid cycle-dependent signal transduction in Staphylococcus epidermidis.

Staphylococcus epidermidis is a skin-resident bacterium and a major cause of biomaterial-associated infections. The transition from residing on the skin to residing on an implanted biomaterial is accompanied by regulatory changes that facilitate bacterial survival in the new environment. These regulatory changes are dependent upon the ability of bacteria to "sense" environmental changes.

Vancomycin-intermediate Staphylococcus aureus strains have impaired acetate catabolism: implications for polysaccharide intercellular adhesin synthesis and autolysis.

The most common mechanism by which Staphylococcus aureus gains resistance to vancomycin is by adapting its physiology and metabolism to permit growth in the presence of vancomycin. Several studies have examined the adaptive changes occurring during the transition to vancomycin-intermediate resistance, leading to a model of vancomycin resistance in which decreased cell wall turnover and autolysis result in increased cell wall thickness and resistance to vancomycin. In the present study, we identified metabolic changes common to vancomycin-intermediate S.

Validity of maternal and perinatal risk factors reported on fetal death certificates.

We sought to estimate the accuracy, relative to maternal medical records, of perinatal risk factors recorded on fetal death certificates. We conducted a validation study of fetal death certificates among women who experienced fetal deaths between 1996 and 2001. The number of previous births, established diabetes, chronic hypertension, maternal fever, performance of autopsy, anencephaly, and Down syndrome had very high accuracy, while placental cord conditions and other chromosomal abnormalities were reported inaccurately.

Error-prone polymerase, DNA polymerase IV, is responsible for transient hypermutation during adaptive mutation in Escherichia coli.

The frequencies of nonselected mutations among adaptive Lac(+) revertants of Escherichia coli strains with and without the error-prone DNA polymerase IV (Pol IV) were compared. This frequency was more than sevenfold lower in the Pol IV-defective strain than in the wild-type strain. Thus, the mutations that occur during hypermutation are due to Pol IV.