189 research outputs found
Dreidimensionale Bewegungsanalyse der HalswirbelsÀule mit dem Zebris Ultraschallsystem
In den Jahren von 1995 bis 1996 wurden im Rahmen dieser Studie in Hannover insgesamt 29 Probanden mit Hilfe des ZebrisÂź Systems untersucht/ gemessen. Dabei wurde eine vollstĂ€ndige Anamnese erhoben sowie eine klinische Untersuchung durchgefĂŒhrt. Es wurde eine Null- Studie erarbeitet.
Diese Studie knĂŒpft an vorangegangene Arbeiten zur mehrdimensionalen Untersuchung der HalswirbelsĂ€ule an. Sie hatten bereits Systeme vorgestellt, die in der Lage sind komplexe BewegungsablĂ€ufe der HalswirbelsĂ€ule zu erfassen.
In dieser Studie ist dabei folgendes festgestellt worden:
Als nichtinvasive Methode mit einem relativ geringen apparativen Aufwand ist die oben beschriebene MeĂmethode eine Alternative zu den radiologischen Aufnahmen wie zum Beispiel den Funktionsaufnahmen, das System ist als ErgĂ€nzung zur konventionellen Röntgenaufnahmen und zum CT bei pathologischen BewegungseinschrĂ€nkung anzusehen.
Das System arbeitet sehr prĂ€zise und zuverlĂ€ssig, wie die Kontrollmessungen ergeben haben. Es bedarf hierbei keinerlei Ăbung die MeĂapparatur ordnungsgemÀà zu plazieren. Sie ist also Untersucher unabhĂ€ngig. Ebenso sind Verlaufsbeobachtungen, Untersucher unabhĂ€ngig, ĂŒber einen langen Zeitraum möglich
Die MeĂmethode ist auĂerdem geeignet die klinische Untersuchung zu objektivieren und zu differenzieren.
Verlaufsbeobachtungen sind Untersucher unabhÀngig möglich. Das System bittet den Vorteil einzeln Bewegungsabschnitte heraus zu arbeiten und zu analysieren.
Die erhobenen MeĂwerte zeigen, das die in dieser Studie ermittelten Werte, mit der bereits publizierten Literatur vergleichbar sind. Zudem sind MeĂwerte erhoben worden die es gilt, mit anderen MeĂmethoden, auf deren Nachvollziehbarkeit zuuntersuchen
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CAMP: An instrumented platform for balloon-borne aerosol particle studies in the lower atmosphere
Airborne observations of vertical aerosol particle distributions are crucial for detailed process studies and model improvements. Tethered balloon systems represent a less expensive alternative to aircraft to probe shallow atmospheric boundary layers (ABLs). This study presents the newly developed cubic aerosol measurement platform (CAMP) for balloon-borne observations of aerosol particle microphysical properties. With an edge length of 35 cm and a weight of 9 kg, the cube is an environmentally robust instrument platform intended for measurements at low temperatures, with a particular focus on applications in cloudy Arctic ABLs. The aerosol instrumentation on board CAMP comprises two condensation particle counters with different lower detection limits, one optical particle size spectrometer, and a miniaturized absorption photometer. Comprehensive calibrations and characterizations of the instruments were performed in laboratory experiments. The first field study with a tethered balloon system took place at the Leibniz Institute for Tropospheric Research (TROPOS) station in Melpitz, Germany, in the winter of 2019. At ambient temperatures between-8 and 15 C, the platform was operated up to a 1.5 km height on 14 flights under both clear-sky and cloudy conditions. The continuous aerosol observations at the ground station served as a reference for evaluating the CAMP measurements. Exemplary profiles are discussed to elucidate the performance of the system and possible process studies. Based on the laboratory instrument characterizations and the observations during the field campaign, CAMP demonstrated the capability to provide comprehensive aerosol particle measurements in cold and cloudy ABLs
Mapping the EQ-5D index by UPDRS and PDQ-8 in patients with Parkinsonâs disease
Background: Clinical studies employ the Unified Parkinsonâs Disease Rating Scale (UPDRS) to measure the severity of Parkinsonâs disease. Evaluations often fail to consider the health-related quality of life (HrQoL) or apply disease-specific instruments. Health-economic studies normally use estimates of utilities to calculate quality-adjusted life years. We aimed to develop an estimation algorithm for EuroQol- 5 dimensions (EQ-5D)-based utilities from the clinical UPDRS or disease-specific HrQoL data in the absence of original utilities estimates. Methods: Linear and fractional polynomial regression analyses were performed with data from a study of Parkinsonâs disease patients (n=138) to predict the EQ-5D index values from UPDRS and Parkinsonâs disease questionnaire eight dimensions (PDQ-8) data. German and European weights were used to calculate the EQ-5D index. The models were compared by R2, the root mean square error (RMS), the Bayesian information criterion, and Pregibonâs link test. Three independent data sets validated the models. Results: The regression analyses resulted in a single best prediction model (R2: 0.713 and 0.684, RMS: 0.139 and 13.78 for indices with German and European weights, respectively) consisting of UPDRS subscores II, III, IVa-c as predictors. When the PDQ-8 items were utilised as independent variables, the model resulted in an R2 of 0.60 and 0.67. The independent data confirmed the prediction models. Conclusion: The best results were obtained from a model consisting of UPDRS subscores II, III, IVa-c. Although a good model fit was observed, primary EQ-5D data are always preferable. Further validation of the prediction algorithm within large, independent studies is necessary prior to its generalised use
LACIS-T - a humid wind tunnel for investigating the interactions between cloud microphysics and turbulence
To improve the fundamental and quantitative understanding of the interactions between cloud microphysical
and turbulent processes, the Leibniz Institute for Tropospheric Research (TROPOS) has built up a new humid
wind tunnel (LACIS-T). LACIS-T allows for the investigation of cloud microphysical processes, such as cloud
droplet activation and freezing, under-well defined thermodynamic and turbulent flow conditions. It therewith
allows for the straight forward continuation, extension, and completion of the cloud microphysics related investigations
carried out at the Leipzig Aerosol Cloud Interaction Simulator (LACIS) under laminar flow conditions.
Characterization of the wind tunnel with respect to flow, thermodynamics, and droplet microphysics is carried
out with probes mounted inside (pitot tube and hot-wire anemometer for mean velocity and fluctuations,
Pt100 sensor for mean temperature, cold-wire sensor for temperature fluctuations is in progress, as well as a
dew-point mirror for mean water vapor concentration, a Lyman-alpha sensor for water vapor fluctuations is in
progress) the measurement section, and from outside with optical detection methods (a laser light sheet is available
for cloud droplet visualization, a digital holography system for detection of cloud droplet size distributions will
be installed for tests in February 2017), respectively. Computational fluid dynamics (CFD) simulations have been
carried out for defining suitable experimental conditions and assisting the interpretation of the experimental data.
In this work, LACIS-T, its fundamental operating principle, and first preliminary results from ongoing
characterization efforts will be presented
Evaluation of the âring signâ and the âcore signâ as a magnetic resonance imaging marker of disease activity and progression in clinically isolated syndrome and early multiple sclerosis
Background: Brain lesions with a hypointense ring or core were described in multiple sclerosis on susceptibility weighted imaging.
Objective: The purpose of this study was to study the evolution and prognostic relevance of susceptibility weighted imaging hypointense lesions in clinically isolated syndrome and early multiple sclerosis.
Methods: Sixty-six early multiple sclerosis and clinically isolated syndrome patients were followed over a median period of 2.9 years (range 1.6-4.6 years) and underwent 3T magnetic resonance imaging including 3D susceptibility weighted imaging and T2-weighted fluid-attenuated inversion recovery. We assessed the presence of susceptibility weighted imaging hypointense core or ring lesions, and Expanded Disability Status Scale at baseline and follow-up.
Results: Of 611 lesions at baseline, 64 (10.5%) had a susceptibility weighted imaging hypointense core, and 28 (4.6%) had a susceptibility weighted imaging hypointense ring. Hypointense ring lesions were larger (p < 0.001) and more T1w hypointense (p = 0.002) than others. During follow-up, hypointense core lesions became susceptibility weighted imaging isointense (52 lesions, 81%); few developed into hypointense ring lesions (two lesions, 3%). Hypointense ring lesions did not shrink on T2-weighted fluid-attenuated inversion recovery images (p = 0.077, trend towards more enlargement compared to others), while hypointense core lesions more often shrunk in comparison to lesions without a hypointense core (p = 0.002). The number of susceptibility weighted imaging hypointense ring lesions at baseline correlated with Expanded Disability Status Scale progression at follow-up (p = 0.021, R = 0.289).
Conclusion: In our cohort of patients with clinically isolated syndrome or early multiple sclerosis, susceptibility weighted imaging hypointense ring lesions were only rarely detectable, but did not shrink and were associated with future disability progression
Knee complaints and consequences on work status; a 10-year follow-up survey among floor layers and graphic designers
<p>Abstract</p> <p>Background</p> <p>The purpose of the study was to examine if knee complaints among floor layers predict exclusion from the trade.</p> <p>Methods</p> <p>In 1994/95 self-reported data were obtained from a cohort of floor layers and graphic designers with and without knee straining work activities, respectively. At follow-up in 2005 the questionnaire survey was repeated. The study population consisted of 81 floor layers and 173 graphic designers who were presently working in their trades at baseline (1995). All participants were men aged 36â70 years in 2005.</p> <p>We computed the risk of losing gainful employment in the trade according to occurrence of knee complaints at baseline, using Cox proportional hazard regression adjusted for a number of potential confounding variables. Moreover, the crude and adjusted odds risk ratio for knee complaints according to status of employment in the trade were computed, using graphic designers as reference.</p> <p>Results</p> <p>A positive but non-significant association between knee complaints lasting more than 30 days the past 12 months and exclusion from the trade was found among floor layers (Hazard Ratio = 1.4, 95% CI = 0.6â3.5).</p> <p>The frequency of self-reported knee complaints was lower among floor layers presently at work in the trade in year 2005 (26.3%) compared with baseline in 1995 (41.1%), while the opposite tendency was seen among graphic designers (20.7% vs. 10.7%).</p> <p>Conclusion</p> <p>The study suggests that knee complaints are a risk factor for premature exclusion from a knee demanding trade. However, low power of the study precludes strong conclusions. The study also indicates a healthy worker effect among floor layers and a survivor effect among graphic designers.</p
TNFAIP3 (A20) is a tumor suppressor gene in Hodgkin lymphoma and primary mediastinal B cell lymphoma
Proliferation and survival of Hodgkin and Reed/Sternberg (HRS) cells, the malignant cells of classical Hodgkin lymphoma (cHL), are dependent on constitutive activation of nuclear factor ÎșB (NF-ÎșB). NF-ÎșB activation through various stimuli is negatively regulated by the zinc finger protein A20. To determine whether A20 contributes to the pathogenesis of cHL, we sequenced TNFAIP3, encoding A20, in HL cell lines and laser-microdissected HRS cells from cHL biopsies. We detected somatic mutations in 16 out of 36 cHLs (44%), including missense mutations in 2 out of 16 Epstein-Barr virusâpositive (EBV+) cHLs and a missense mutation, nonsense mutations, and frameshift-causing insertions or deletions in 14 out of 20 EBVâ cHLs. In most mutated cases, both TNFAIP3 alleles were inactivated, including frequent chromosomal deletions of TNFAIP3. Reconstitution of wild-type TNFAIP3 in A20-deficient cHL cell lines revealed a significant decrease in transcripts of selected NF-ÎșB target genes and caused cytotoxicity. Extending the mutation analysis to primary mediastinal B cell lymphoma (PMBL), another lymphoma with constitutive NF-ÎșB activity, revealed destructive mutations in 5 out of 14 PMBLs (36%). This report identifies TNFAIP3 (A20), a key regulator of NF-ÎșB activity, as a novel tumor suppressor gene in cHL and PMBL. The significantly higher frequency of TNFAIP3 mutations in EBVâ than EBV+ cHL suggests complementing functions of TNFAIP3 inactivation and EBV infection in cHL pathogenesis
Attack-related damage of Thalamic Nuclei in Neuromyelitis Optica Spectrum Disorders
OBJECTIVES: In neuromyelitis optica spectrum disorders (NMOSD) thalamic damage is controversial, but thalamic nuclei were never studied separately. We aimed at assessing volume loss of thalamic nuclei in NMOSD. We hypothesised that only specific nuclei are damaged, by attacks affecting structures from which they receive afferences: the lateral geniculate nucleus (LGN), due to optic neuritis (ON) and the ventral posterior nucleus (VPN), due to myelitis. METHODS: Thirty-nine patients with aquaporin 4-IgG seropositive NMOSD (age: 50.1±14.1 years, 36 women, 25 with prior ON, 36 with prior myelitis) and 37 healthy controls (age: 47.8 ± 12.5 years, 32 women) were included in this cross-sectional study. Thalamic nuclei were assessed in magnetic resonance images, using a multi-atlas-based approach of automated segmentation. Retinal optical coherence tomography was also performed. RESULTS: Patients with ON showed smaller LGN volumes (181.6±44.2âmm 3 ) compared with controls (198.3±49.4âmm 3 ; B=-16.97, p=0.004) and to patients without ON (206.1±50âmm 3 ; B=-23.74, p=0.001). LGN volume was associated with number of ON episodes (Rho=-0.536, p<0.001), peripapillary retinal nerve fibre layer thickness (B=0.70, p<0.001) and visual function (B=-0.01, p=0.002). Although VPN was not smaller in patients with myelitis (674.3±67.5âmm 3 ) than controls (679.7±68.33; B=-7.36, p=0.594), we found reduced volumes in five patients with combined myelitis and brainstem attacks (B=-76.18, p=0.017). Volumes of entire thalamus and other nuclei were not smaller in patients than controls. CONCLUSION: These findings suggest attack-related anterograde degeneration rather than diffuse thalamic damage in NMOSD. They also support a potential role of LGN volume as an imaging marker of structural brain damage in these patients
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