In vitro measurement conditions for optical coherence tomography (OCT).

CONCLUSION: Tissue marking with soot-covered fine needles enables the optical coherence tomography (OCT) scanning plane to be localized within the histological specimen to an accuracy of approximately 50 microm. Tissue water content is an especially important parameter for in vitro measurements. Dehydration tends to produce an increase in surface reflections and a reduction in imaging depth. OBJECTIVES: The aim of this in vitro study was to evaluate parameters relevant to the visualization and conservation process to allow optimal images to be generated for later differentiation between healthy and degenerated tissue in vivo. MATERIALS AND METHODS: Various methods of marking samples were applied in vitro to achieve accurate overlaps of the OCT scanning plane and the corresponding section of the histological specimen. The influence of temperature and tissue water content was investigated using both porcine and human tissue. Samples were marked using fine needles, ablation craters generated by laser application, and colour markers introduced into the tissue. RESULTS: It was demonstrated that the water content of tissue exerts a direct influence on OCT imaging, whereas above 15 degrees C temperature had no effect on image quality. With regard to the marking of samples, the best results were obtained using sooted fine needles.

"This is your meeting": a qualitative study of person-centered planning.

Participant observation and in-depth interviews were conducted to determine processes involved in person-centered planning. Initial planning meetings of 6 individuals were studied in connection with a project to assist young adults in transition from school to adult life. The organization and structure, facilitation process, participation of families, professionals, friends, and the focal individual were described. Although the major goal of the project was to assure that this was the individual's own meeting, implementation of this principle was constrained in several ways, including facilitators' tendency to behave according to prior roles and training. Six months following initiation, several positive outcomes could be attributed to the planning process. Further, many unplanned positive outcomes appeared to result from person-centered planning.

Workplace culture, social interactions, and supports for transition-age young adults.

The role of the workplace and its culture in supporting social inclusion and workplace support for employees with disabilities is discussed and results of a qualitative study of the workplace experiences of 8 young adults with developmental disabilities presented. Data were collected using participant observation and semi-structured interviews. Four characteristics of supportive workplaces were identified: (a) multiple context relationships, (b) specific social opportunities, (c) a personal and team-building management style, and (d) interdependent job designs. The more supportive workplaces had all of these characteristics, suggesting that collectively they represent key features of a supportive workplace culture. Implications for job development and job creation are identified.

[Bone ablation using ultrashort laser pulses. A new technique for middle ear surgery]. / Knochenablation mittels ultrakurzer Laserpulse. Eine neue Technik für die Mittelohrchirurgie.

OBJECTIVES: Laser applications within the tympanic cavity area are widely accepted. Commonly used systems are CO(2), argon, KTP and erbium devices. The disadvantages are heat development and/or acoustic load of the inner ear. A new laser with ultra short pulses was examined concerning its ablation characteristics and tested for possible applications in the tympanic cavity. METHODS: Investigations on human ossicles and porcine compacta were performed with a femtosecond laser in order to determine the ablation parameters. This included measurements of the dependency of the threshold energy on the pulse duration and the determination of the ablation ratio using different pulse energy levels. On the basis of histological slices the thermal damages of the bone were examined. Additionally, the processed samples were analyzed with an optical microscope and with a scanning electron microscope in order to evaluate the quality of the perforations. RESULTS: The measurements showed that the threshold energy has a lower level than the threshold energy of the conventional laser systems. At a pulse duration of 180 fs the smallest fluence, with which an erosion can be achieved, is below 1 J/cm(2). With increasing pulse duration the necessary threshold energy also rises. Due to the low energy level necessary for ablation and the extremely short pulse duration, less thermal damage is induced to the surrounding bone tissue as compared to conventional laser systems. The analysis of the scanning electron microscope demonstrates the extreme precision of this laser system. The achieved accuracy of the incisions and drillings ranges in the microm-area. CONCLUSIONS: The fs laser represents a new surgical tool for middle ear surgery. It works efficiently and in a touch-free procedure. Due to its high precision and the reduced side effects an advantage in the handling of bony structures is to be expected in relation to other laser systems. Apart from the perforation of the stapes footplate, in particular the handling and modelling of the incus, a further field of applications includes enhanced coupling, e. g. for implantable hearing aids and ossicular chain replacement prosthesis.

How adequate is adequate for the collection of endocervical specimens for Chlamydia trachomatis testing?

BACKGROUND: Endocervical specimen adequacy has been assessed by subjective criteria that are based on arbitrarily chosen thresholds for the presence of target cells observed on microscopic slide examinations. GOAL OF THIS STUDY: To assess the relationship of chlamydia test positivity to specimen adequacy with the use of a semi-quantitative cytologic staining method for assessing endocervical specimen collection cellularity. STUDY DESIGN: Endocervical specimens for chlamydia testing (PACE 2, GenProbe, San Diego, CA) and for a slide cytologic examination (n = 3,500) were collected in parallel. A semi-quantitative cytologic examination to determine a specimen adequacy (SA) score was performed for every chlamydia-positive result (n = 163) and approximately every fifth negative result (n = 626). The Chi-square test for linear trends was used to assess the relationship between SA scores and chlamydia positivity. The median SA scores for chlamydia-positive and negative slides were compared. RESULTS: The median SA scores for chlamydia-positive and -negative slides were 27 and 20, respectively (P < 0.001). Chlamydia positivity rates increased with increasing specimen adequacy scores (0-9, 2.7%; 10-19, 15.1%; 20-29, 24.8%; and 30-45, 31.3%; Chi-square for linear trend: P < 0.001). CONCLUSION: These results demonstrate a linear relationship between the numbers of cells observed on an endocervical smear and chlamydia positivity rather than the threshold concept in practice. The semiquantitative cytologic technique offers an objective method for further evaluating specimen adequacy for Chlamydia trachomatis testing.

Lack of correlation between plasma 4-hydroxyglutethimide and severity of coma in acute glutethimide poisoning. A case report and brief review of the literature.

Glutethimide poisoning is characterised by coma, anticholinergic poisoning syndrome, hypotension, and other complications. Previous studies have shown that the severity of intoxication does not correlate with plasma glutethimide concentrations in individual patients. Glutethimide is partly converted to 4-hydroxyglutethimide, a metabolite which accumulates in the plasma of humans, and which has been thought to contribute to coma after plasma glutethimide concentrations have fallen. We followed plasma concentrations of glutethimide and 4-hydroxyglutethimide in a man who overdosed with glutethimide. Plasma 4-hydroxyglutethimide concentrations did not correlate with the degree of coma in our patient, and actually rose as the patient awakened. Other studies also indicate that 4-hydroxyglutethimide may not play an important role in glutethimide poisoning.