A digital holography ex situ measurement characterization of plasma-exposed surface erosion from an electrothermal arc source.

Digital holography has been proposed to fulfill a need for an imaging diagnostic capable of in situ monitoring of surface erosion caused by plasma-material interaction in nuclear fusion devices. A digital holography diagnostic for 3D surface erosion measurement has been developed at Oak Ridge National Laboratory with the goal of deployment on a plasma device. A proof-of-concept in situ demonstration is planned which would involve measurement of plasma erosion on targets exposed to an electrothermal arc source. This work presents the results of an ex situ characterization of the capability and limitations of holographic imaging of targets exposed to the arc source. Targets were designed to provide a fiducial for comparison of deformed and unaffected areas. The results indicated that the average net erosion was ∼150 nm/plasma exposure, which is expected to be within the diagnostic's measurement capacity. Surface roughness averages determined by holographic image analysis showed good agreement with measurements taken with a profilometer. The limit of the holography diagnostic's x-y spatial resolution was characterized by comparison with scanning electron microscope imaging.

Cerebral embolization presenting as delayed, severe obtundation in the postanesthesia care unit after total hip arthroplasty.

Catastrophic neurologic events occur rarely postoperatively and must be diagnosed quickly. A 63-year-old woman who had undergone uneventful total hip arthroplasty experienced obtundation after admission to the postanesthesia care unit. Cranial magnetic resonance imaging revealed multiple lesions consistent with ischemia or infarction, and fat cerebral embolism was diagnosed. We describe the numerous complications that may occur in patients in the postanesthesia care unit and review the differential diagnosis of altered mental status in such patients. Paradoxical cerebral fat embolization must be considered in the differential diagnosis of altered mental status after pelvic or long bone fracture or lower extremity major joint replacement, and this condition may occur despite normal pulmonary function and no patent foramen ovale or right-to-left intracardiac shunt. Magnetic resonance imaging with T2-weighted sequences is the cranial imaging study of choice for early evaluation of patients with sudden multifocal neurologic deficits and suspected fat embolism syndrome.

Left-sided Pseudomonas aeruginosa endocarditis in patients without injection drug use.

We aimed to determine the clinical features, predisposing factors, and outcome of left-sided Pseudomonas aeruginosa endocarditis in persons with no history of injection drug use. We performed a retrospective review of patient medical records from Mayo Clinic (Rochester, MN; Scottsdale, AZ; and Jacksonville, FL) for all cases of left-sided P. aeruginosa endocarditis. We identified 4 cases. We present these cases, as well as a review of the English-language medical literature. Data gathered included the year the case was reported; the valve involved; treatment, including valve replacement surgery; and outcome, if known. Left-sided P. aeruginosa endocarditis in persons without injection drug use is a rare but serious infection, with a history of instrumentation as a common predisposing condition. Valvular surgery is indicated, when possible, for the best chance of survival, along with extended therapy with combination antibiotics for complete recovery.

Expressive writing as a smoking cessation treatment adjunct for young adult smokers.

This investigation evaluated the efficacy of expressive writing as a treatment adjunct to a brief office smoking cessation intervention plus nicotine patch therapy in young adults. Participants aged 18-24 years were randomized to a brief office intervention (n=99) or to an expressive writing plus brief office intervention (n=97). Both conditions received four individual visits plus 6 weeks of nicotine patch therapy, which began on the quit date following the week 2 visit. Participants in the expressive writing plus brief intervention condition wrote for 2 consecutive days before and 3 consecutive days after the quit date. The brief office intervention group completed a control writing assignment. At end of treatment (week 8), biochemically confirmed 7-day point-prevalence abstinence for the expressive writing plus brief office intervention condition was significantly greater than for the brief office condition (33% vs. 20%, p=.043, OR=2.0, 95% CI=1.0-3.7, from a logistic regression adjusting for gender). At 24 and 52 weeks, abstinence rates were similar for the brief office intervention versus expressive writing plus brief office intervention (12% vs. 11% at 24 weeks; 11% vs. 11% at 52 weeks). The results suggest that expressive writing has promise as a smoking cessation treatment adjunct for young adults. Lengthier interventions or the use of boosters should be tested to extend treatment effects. However, participants reported a low level of enthusiasm for the expressive writing, which may be a barrier to implementing it over a longer time frame. Therefore, other modes of delivering expressive writing to young adult cigarette smokers should be explored.

Concomitant alterations of desmosomes, adhesiveness, and diffusion through gap junction channels in a rat ovarian transformation model system.

Gap junctional intercellular communication (GJIC), desmosomes, and cell movement were evaluated in a rat ovarian epithelial cell model system which consisted of an immortalized clonal cell line (SIGC), a pSV3neotransfected clonal derivative (SV-SIGC), and a nude mouse SV-SIGC-tumor-derived cell line (T-SV-SIGC). Complementary ultrastructural, indirect immunofluorescence, and Western blot data identified a relatively small loss of desmosomes and associated cytokeratins in SV-SIGC compared to SIGC but a near total loss in T-SV-SIGC. SIGC and SV-SIGC migrated outward from monolayer-coated microcarrier beads as epithelial sheets, whereas in T-SV-SIGC there was dissociation and migration of individual fibroblastoid cells. GJIC was assessed by fluorescence recovery after photobleaching (gap FRAP) and equations based on Fick's first law of diffusion were derived to quantitatively compare GJIC of systems with different recovery equilibria after photobleaching. Taken together the data suggested that GJIC in SIGC was quantitatively reduced to similar levels by various conditions associated with reduced cell-cell adhesiveness including transformation to T-SV-SIGC, mitosis, and culture in low calcium medium. These results supported linkage between changes in desmosomal adhesiveness, cell movement, and GJIC.

Concurrent analysis of intracellular glutathione content and gap junctional intercellular communication.

The potential for performing dual analysis of intracellular glutathione levels and assessment of gap junctional intercellular communication with thiol-specific fluorescent probes in anchored cells was evaluated. Gap junction-mediated diffusion of monochlorobimane and 5-chloromethylfluorescein diacetate following intracellular loading and conjugation with glutathione was compared with 5-carboxyfluorescein diacetate (which is routinely used in laser cytometry to monitor intercellular communication) by means of fluorescence recovery after photobleaching using a variety of communication-competent and communication-incompetent cells. The rate of diffusion of fluorescence among communication-competent cells was inversely proportional to the size of the fluorescent probe employed. The thiol-specific probes were also employed to monitor depletion and synthesis of glutathione following treatments to inhibit glutathione synthesis or consume glutathione by adduct formation. Analysis of gap junctional intercellular communication following glutathione depletion revealed a direct correlation between glutathione levels and intercellular communication. These studies support the utility of the thiol-specific probes to monitor the respective role of cellular glutathione and intercellular communication in the mechanisms of cellular injury.