Publications by authors named "Keith Beck"

A minimally destructive technique for the determination of dyes in finished fibers provides an important tool for crime scene and other forensic investigations. The analytical power and the minimal sample consumption of time-of-flight-secondary ion mass spectrometric (TOF-SIMS) analysis provides the ability to obtain definitive molecular and elemental information relevant to fiber identification, including identification of dyes, from a very small volume of sample. For both fiber surface analysis and, with the aid of cryomicrotomy, fiber cross-section analysis, TOF-SIMS was used to identify various dyes in finished textile fibers.

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Color Index Disperse Yellow 42 (DY42), a high-volume disperse dye for polyester, was used to compare the capabilities of the LTQ-Orbitrap XL and the LTQ-FT-ICR with respect to mass measurement accuracy (MMA), spectral accuracy, and sulfur counting. The results of this research will be used in the construction of a dye database for forensic purposes; the additional spectral information will increase the confidence in the identification of unknown dyes found in fibers at crime scenes. Initial LTQ-Orbitrap XL data showed MMAs greater than 3 ppm and poor spectral accuracy.

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We describe a case of West Nile virus (WNV) infection in an HIV-infected patient who presented with an isolated flaccid monoparesis of the right upper extremity. To our knowledge, this is the first reported case of flaccid paralysis caused by WNV infection in an HIV-infected patient. We then review the medical literature on WNV infection occurring among patients who are infected with HIV.

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Objective: We compared the effectiveness of a biweekly regimen of 150 mg nandrolone with placebo in HIV-infected men with mild to moderate weight loss and contrasted its effects against a Food and Drug Administration-approved regimen of recombinant human (rh)GH.

Methods: In this placebo-controlled, randomized, 12-wk trial, placebo and nandrolone (150 mg im biweekly) were administered double blind, and rhGH (6 mg sc daily) was administered in an open-label manner. Participants were HIV-infected men with 5-15% weight loss over 6 months and on stable antiretroviral therapy for more than 12 wk.

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We report a case of concurrent cerebral infection with Trypanosoma cruzi and Toxoplasma gondii in a patient with acquired immunodeficiency syndrome (AIDS). A 22-year-old El Salvadoran man initially improved during receipt of antitoxoplasmosis therapy, but he had rapidly progressive hemiplegia. Magnetic resonance imaging showed an abnormal finding in the left internal capsule, and cytological analysis of cerebrospinal fluid revealed T.

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In a cohort of 128 human immunodeficiency virus-infected patients, we found that patients' knowledge of antiretroviral dosing was suboptimal at regimen initiation but improved with time. Poor medication knowledge 8 weeks after regimen initiation was associated with lower adherence and with a lower level of literacy in a multivariate model (P=.03).

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Purpose: An understanding of the situations in which adherence lapses occur is critical to the design of effective interventions to enhance adherence. We investigated whether a switch in antiretroviral medications affected adherence by examining a prospective observational cohort of 128 patients who began a new antiretroviral regimen.

Method: Adherence was measured using electronic devices, pill counts, and self-reports, which were combined into a composite adherence measure and expressed as the proportion of prescribed medication taken.

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Objective: Adherence to complex antiretroviral therapy (ART) is critical for HIV treatment but difficult to achieve. The development of interventions to improve adherence requires detailed information regarding barriers to adherence. However, short follow-up and inadequate adherence measures have hampered such determinations.

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Objective: Adherence to combination antiretroviral therapy is critical for clinical and virologic success in HIV-infected patients. To combat poor adherence, clinicians must identify nonadherent patients so they can implement interventions. However, little is known about the accuracy of these assessments.

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