Occupational risk of COVID-19 in foreign-born employees in Denmark.

BACKGROUND: Foreign-born workers in high-income countries experience higher rates of COVID-19 but the causes are only partially known. AIMS: To examine if the occupational risk of COVID-19 in foreign-born workers deviates from the risk in native-born employees in Denmark. METHODS: Within a registry-based cohort of all residents employed in Denmark (n = 2 451 542), we identified four-digit DISCO-08 occupations associated with an increased incidence of COVID-19-related hospital admission during 2020-21 (at-risk occupations). The sex-specific prevalence of at-risk employment in foreign born was compared with the prevalence in native born. Moreover, we examined if the country of birth modified the risk of a positive SARS-CoV-2 polymerase chain reaction (PCR) test and COVID-19-related hospital admission in at-risk occupations. RESULTS: Workers born in low-income countries and male workers from Eastern Europe more often worked in at-risk occupations (relative risks between 1.16 [95% confidence interval {CI} 1.14-1.17] and 1.87 [95% CI 1.82-1.90]). Being foreign-born modified the adjusted risk of PCR test positivity (test for interaction P < 0.0001), primarily because of higher risk in at-risk occupations among men born in Eastern European countries (incidence rate ratio [IRR] 2.39 [95% CI 2.09-2.72] versus IRR 1.19 [95% CI 1.14-1.23] in native-born men). For COVID-19-related hospital admission, no overall interaction was seen, and in women, country of birth did not consistently modify the occupational risk. CONCLUSIONS: Workplace viral transmission may contribute to an excess risk of COVID-19 in male workers born in Eastern Europe, but most foreign-born employees in at-risk occupations seem not to be at higher occupational risk than native born.

First Accurate Normalization of the ß-delayed α Decay of

The ^{12}C(α,γ)^{16}O reaction plays a central role in astrophysics, but its cross section at energies relevant for astrophysical applications is only poorly constrained by laboratory data. The reduced α width, γ_{11}, of the bound 1^{-} level in ^{16}O is particularly important to determine the cross section. The magnitude of γ_{11} is determined via sub-Coulomb α-transfer reactions or the ß-delayed α decay of ^{16}N, but the latter approach is presently hampered by the lack of sufficiently precise data on the ß-decay branching ratios. Here we report improved branching ratios for the bound 1^{-} level [b_{ß,11}=(5.02±0.10)×10^{-2}] and for ß-delayed α emission [b_{ßα}=(1.59±0.06)×10^{-5}]. Our value for b_{ßα} is 33% larger than previously held, leading to a substantial increase in γ_{11}. Our revised value for γ_{11} is in good agreement with the value obtained in α-transfer studies and the weighted average of the two gives a robust and precise determination of γ_{11}, which provides significantly improved constraints on the ^{12}C(α,γ) cross section in the energy range relevant to hydrostatic He burning.

Non-Gaussian diffusion MRI of gray matter is associated with cognitive impairment in multiple sclerosis.

BACKGROUND: Non-Gaussian diffusion imaging by using diffusional kurtosis imaging (DKI) allows assessment of isotropic tissue as of gray matter (GM), an important limitation of diffusion tensor imaging (DTI). OBJECTIVE: In this study, we describe DKI and DTI metrics of GM in multiple sclerosis (MS) patients and their association with cognitive deficits. METHODS: Thirty-four patients with relapsing-remitting MS and 17 controls underwent MRI on a 3T scanner including a sequence for DKI with 30 diffusion directions and 3b values for each direction. Mean kurtosis (MK), mean diffusivity and fractional anisotropy (FA) of cortical and subcortical GM were measured using histogram analysis. Spearman rank correlations were used to characterize associations among imaging measures and clinical/neuropsychological scores. RESULTS: In cortical GM, a significant decrease of MK (0.68 vs. 0.73; p < 0.001) and increase of FA (0.16 vs. 0.13; p < 0.001) was found in patients compared to controls. Decreased cortical MK was correlated with poor performance on the Delis-Kaplan Executive Function System test (r = 0.66, p = 0.01). CONCLUSION: Mean kurtosis is sensitive to abnormality in GM of MS patients and can provide information that is complementary to that of conventional DTI-derived metrics. The association between MK and cognitive deficits suggests that DKI might serve as a clinically relevant biomarker for cortical injury.

Diffusional kurtosis imaging reveals a distinctive pattern of microstructural alternations in idiopathic generalized epilepsy.

OBJECTIVES: Idiopathic generalized epilepsy (IGE) arises from paroxysmal dysfunctions of the thalamo-cortical network. One of the hallmarks of IGE is the absence of visible abnormalities on routine magnetic resonance imaging (MRI). However, recent quantitative MRI studies showed cortical-subcortical structural abnormalities in IGE, but the extent of abnormalities has been inconsistent in the literature. The inconsistencies may be associated with complex microstructural abnormalities in IGE that are not completely detectable using conventional diffusion tensor imaging methods. The goal of this study was to investigate white-matter (WM) microstructural abnormalities in patients with IGE using diffusional kurtosis imaging (DKI). MATERIALS AND METHODS: We obtained DKI and volumetric T1-weighted images from 14 patients with IGE and 25 matched healthy controls. Using tract-based spatial statistics, we performed voxel-wise group comparisons in the parametric maps generated from DKI: mean diffusivity (MD), fractional anisotropy (FA), and mean kurtosis (MK), and in probabilistic maps of WM volume generated by voxel-based morphometry. RESULTS: We observed that conventional microstructural measures (MD and FA) revealed WM abnormalities in thalamo-cortical projections, whereas MK disclosed a broader pattern of WM abnormalities involving thalamo-cortical and cortical-cortical projections. CONCLUSIONS: Even though IGE is traditionally considered a 'non-lesional' form of epilepsy, our results demonstrated pervasive thalamo-cortical WM microstructural abnormalities. Particularly, WM abnormalities shown by MK further extended into cortical-cortical projections. This suggests that the extent of microstructural abnormalities in thalamo-cortical projections in IGE may be better assessed through the diffusion metrics provided by DKI.

Associations between psychosocial work environment factors and first-time and recurrent treatment for depression: a prospective cohort study of 24,226 employees.

AIMS: Adverse factors in the psychosocial work environment are associated with the onset of depression among those without a personal history of depression. However, the evidence is sparse regarding whether adverse work factors can also play a role in depression recurrence. This study aimed to prospectively examine whether factors in the psychosocial work environment are associated with first-time and recurrent treatment for depression. METHODS: The study included 24,226 participants from the Danish Well-being in Hospital Employees study. We measured ten individual psychosocial work factors and three theoretical constructs (effort-reward imbalance, job strain and workplace social capital). We ascertained treatment for depression through registrations of hospital contacts for depression (International Statistical Classification of Diseases and Related Health Problems version 10 [ICD-10]: F32 and F33) and redeemed prescriptions of antidepressant medication (Anatomical Therapeutic Chemical [ATC]: N06A) in Danish national registries. We estimated the associations between work factors and treatment for depression for up to 2 years after baseline among those without (first-time treatment) and with (recurrent treatment) a personal history of treatment for depression before baseline. We excluded participants registered with treatment within 6 months before baseline. In supplementary analyses, we extended this washout period to up to 2 years. We applied logistic regression analyses with adjustment for confounding. RESULTS: Among 21,156 (87%) participants without a history of treatment for depression, 350 (1.7%) had first-time treatment during follow-up. Among the 3070 (13%) participants with treatment history, 353 (11%) had recurrent treatment during follow-up. Those with a history of depression generally reported a more adverse work environment than those without such a history. Baseline exposure to bullying (odds ratio [OR] = 1.72, 95% confidence interval [95% CI]: 1.30-2.32), and to some extent also low influence on work schedule (OR = 1.27, 95% CI: 0.97-1.66) and job strain (OR = 1.24, 95% CI: 0.97-1.57), was associated with first-time treatment for depression during follow-up. Baseline exposure to bullying (OR = 1.40, 95% CI: 1.04-1.88), lack of collaboration (OR = 1.31, 95% CI: 1.03-1.67) and low job control (OR = 1.27, 95% CI: 1.00-1.62) were associated with recurrent treatment for depression during follow-up. However, most work factors were not associated with treatment for depression. Using a 2-year washout period resulted in similar or stronger associations. CONCLUSIONS: Depression constitutes a substantial morbidity burden in the working-age population. Specific adverse working conditions were associated with first-time and recurrent treatment for depression and improving these may contribute to reducing the onset and recurrence of depression.

Quantitative Diffusion and Spectroscopic Neuroimaging Combined with a Novel Early-Developmental Assessment Improves Models for 1-Year Developmental Outcomes.

BACKGROUND AND PURPOSE: Preterm infants are at risk for overt and silent CNS injury, with developmental consequences that are difficult to predict. The novel Specific Test of Early Infant Motor Performance, administered in preterm infants at term age, is indicative of later developmental gross motor and cognitive scores at 12 months. Here, we assessed whether functional performance on this early assessment correlates with CNS integrity via MR spectroscopy or diffusional kurtosis imaging and whether these quantitative neuroimaging methods improve predictions for future 12-month developmental scores. MATERIALS AND METHODS: MR spectroscopy and quantitative diffusion MR imaging data were acquired in preterm infants (n = 16) at term. Testing was performed at term and 3 months using the Specific Test of Early Infant Motor Performance and the Bayley Scales of Infant and Toddler Development, Third Edition, at 12 months. We modeled the relationship of MR spectroscopy and diffusion MR imaging data with both test scores via multiple linear regression. RESULTS: MR spectroscopy NAA ratios at a TE of 270 ms in the frontal WM and basal ganglia and kurtosis metrics in major WM tracts correlated strongly with total Specific Test of Early Infant Motor Performance scores. The addition of MR spectroscopy and diffusion separately improved the functional predictions of 12-month outcomes. CONCLUSIONS: Microstructural integrity of the major WM tracts and metabolism in the basal ganglia and frontal WM strongly correlate with early developmental performance, suggesting that the Specific Test of Early Infant Motor Performance reflects CNS integrity after preterm birth. This study demonstrates that combining quantitative neuroimaging and early functional movement improves the prediction of 12-month outcomes in premature infants.

Intravoxel incoherent motion imaging of tumor microenvironment in locally advanced breast cancer.

Diffusion-weighted imaging plays important roles in cancer diagnosis, monitoring, and treatment. Although most applications measure restricted diffusion by tumor cellularity, diffusion-weighted imaging is also sensitive to vascularity through the intravoxel incoherent motion effect. Hypervascularity can confound apparent diffusion coefficient measurements in breast cancer. We acquired multiple b-value diffusion-weighted imaging at 3 T in a cohort of breast cancer patients and performed biexponential intravoxel incoherent motion analysis to extract tissue diffusivity (D(t)), perfusion fraction (f(p)), and pseudodiffusivity (D(p)). Results indicated significant differences between normal fibroglandular tissue and malignant lesions in apparent diffusion coefficient mean (±standard deviation) values (2.44 ± 0.30 vs. 1.34 ± 0.39 µm(2)/msec, P < 0.01) and D(t) (2.36 ± 0.38 vs. 1.15 ± 0.35 µm(2)/msec, P < 0.01). Lesion diffusion-weighted imaging signals demonstrated biexponential character in comparison to monoexponential normal tissue. There is some differentiation of lesion subtypes (invasive ductal carcinoma vs. other malignant lesions) with f(p) (10.5 ± 5.0% vs. 6.9 ± 2.9%, P = 0.06), but less so with D(t) (1.14 ± 0.32 µm(2)/msec vs. 1.18 ± 0.52 µm(2)/msec, P = 0.88) and D(p) (14.9 ± 11.4 µm(2)/msec vs. 16.1 ± 5.7 µm(2)/msec, P = 0.75). Comparison of intravoxel incoherent motion biomarkers with contrast enhancement suggests moderate correlations. These results suggest the potential of intravoxel incoherent motion vascular and cellular biomarkers for initial grading, progression monitoring, or treatment assessment of breast tumors.

Quantitative assessment of iron accumulation in the deep gray matter of multiple sclerosis by magnetic field correlation imaging.

BACKGROUND AND PURPOSE: Deposition of iron has been recognized recently as an important factor of pathophysiologic change including neurodegenerative processes in multiple sclerosis (MS). We propose that there is an excess accumulation of iron in the deep gray matter in patients with MS that can be measured with a newly developed quantitative MR technique--magnetic field correlation (MFC) imaging. MATERIALS AND METHODS: With a 3T MR system, we studied 17 patients with relapsing-remitting MS and 14 age-matched healthy control subjects. We acquired MFC imaging using an asymmetric single-shot echo-planar imaging sequence. Regions of interest were selected in both deep gray matter and white matter regions, and the mean MFC values were compared between patients and controls. We also correlated the MFC data with lesion load and neuropsychologic tests in the patients. RESULTS: MFC measured in the deep gray matter in patients with MS was significantly higher than that in the healthy controls (P < or = .03), with an average increase of 24% in the globus pallidus, 39.5% in the putamen, and 30.6% in the thalamus. The increased iron deposition measured with MFC in the deep gray matter in the patients correlated positively with the total number of MS lesions (thalamus: r = 0.61, P = .01; globus pallidus: r = 0.52, P = .02). A moderate but significant correlation between the MFC value in the deep gray matter and the neuropsychologic tests was also found. CONCLUSION: Quantitative measurements of iron content with MFC demonstrate increased accumulation of iron in the deep gray matter in patients with MS, which may be associated with the disrupted iron outflow pathway by lesions. Such abnormal accumulation of iron may contribute to neuropsychologic impairment and have implications for neurodegenerative processes in MS.

Solute Partitioning in Micelles: Combining Molecular Dynamics Simulations, COSMOmic, and Experiments.

The partition equilibria of solutes between micelles and an aqueous phase is a key factor in many applications. Depending on the task, many micelle-solute combinations are possible. Therefore, theoretical methods to predict the partition behavior in micellar systems are needed. Here, two predictive methods are evaluated and compared. First, it is shown how molecular dynamics simulations (MD) with the umbrella sampling method can be used to calculate free energy profiles in micellar systems. The second applied method is an extension of the COSMO-RS theory to anisotropic systems termed COSMOmic. Both methods are compared by means of free energy profiles and experimental micelle/water partition coefficients. A particular focus is on the partitioning of ionized solutes. As experimental data for partitioning in micelles especially for charged solutes is rare, partition coefficients were also determined experimentally. To get a general understanding of micelles examples of all micelle classes (classified by headgroup charge) are studied: nonionic Triton X-114 (TX114), zwitterionic miltefosine (HePC), anionic sodium dodecyl sulfate (SDS), and cationic cetyltrimethylammonium bromid (CTAB). The free energy profiles of neutral solutes obtained from MD simulations and COSMOmic are in an overall good agreement, and partition coefficients from both methods are in good agreement with experimental data. Depending on the system, the results for charged solutes show some deviations between the methods and experimental data.

Diffusional Kurtosis Imaging of the Corticospinal Tract in Multiple Sclerosis: Association with Neurologic Disability.

BACKGROUND AND PURPOSE: Multiple sclerosis is an autoimmune disorder resulting in progressive neurologic disability. Our aim was to evaluate the associations between diffusional kurtosis imaging-derived metrics for the corticospinal tract and disability in multiple sclerosis. MATERIALS AND METHODS: Forty patients with MS underwent brain MR imaging including diffusional kurtosis imaging. After we masked out T2 hyperintense lesions, the fractional anisotropy, mean diffusivity, radial diffusivity, axial diffusivity, mean kurtosis, radial kurtosis, and axial kurtosis were estimated for the corticospinal tract. Disability was quantified by using the Expanded Disability Status Scale at the time of MR imaging and 12 months post-MR imaging. The Pearson correlation coefficient and linear regression analyses were conducted to evaluate the associations between diffusion metrics and disability. RESULTS: Significant correlations were found between the Expanded Disability Status Scale scores during the baseline visit and age (r = 0.47), T2 lesion volume (r = 0.38), corticospinal tract mean diffusivity (r = 0.41), radial diffusivity (r = 0.41), axial diffusivity (r = 0.34), fractional anisotropy (r = -0.36), and radial kurtosis (r = -0.42). Significant correlations were also found between the Expanded Disability Status Scale scores at 12-month follow-up and age (r = 0.38), mean diffusivity (r = 0.45), radial diffusivity (r = 0.41), axial diffusivity (r = 0.45), mean kurtosis (r = -0.42), radial kurtosis (r = -0.56), and axial kurtosis (r = -0.36). Linear regression analyses demonstrated significant associations among radial kurtosis, age, and Expanded Disability Status Scale score during the baseline visit, while radial kurtosis was the only variable associated with Expanded Disability Status Scale score for the 12-month follow-up. CONCLUSIONS: Radial kurtosis of the corticospinal tract may have an association with neurologic disability in MS.

Diffusional Kurtosis Imaging and Motor Outcome in Acute Ischemic Stroke.

BACKGROUND AND PURPOSE: Motor impairment is the most common deficit after stroke. Our aim was to evaluate whether diffusional kurtosis imaging can detect corticospinal tract microstructural changes in the acute phase for patients with first-ever ischemic stroke and motor impairment and to assess the correlations between diffusional kurtosis imaging-derived diffusion metrics for the corticospinal tract and motor impairment 3 months poststroke. MATERIALS AND METHODS: We evaluated 17 patients with stroke who underwent brain MR imaging including diffusional kurtosis imaging within 4 days after the onset of symptoms. Neurologic evaluation included the Fugl-Meyer Upper Extremity Motor scale in the acute phase and 3 months poststroke. For the corticospinal tract in the lesioned and contralateral hemispheres, we estimated with diffusional kurtosis imaging both pure diffusion metrics, such as the mean diffusivity and mean kurtosis, and model-dependent quantities, such as the axonal water fraction. We evaluated the correlations between corticospinal tract diffusion metrics and the Fugl-Meyer Upper Extremity Motor scale at 3 months. RESULTS: Among all the diffusion metrics, the largest percentage signal changes of the lesioned hemisphere corticospinal tract were observed with axial kurtosis, with an average 12% increase compared with the contralateral corticospinal tract. The strongest associations between the 3-month Fugl-Meyer Upper Extremity Motor scale score and diffusion metrics were found for the lesioned/contralateral hemisphere corticospinal tract mean kurtosis (ρ = -0.85) and axial kurtosis (ρ = -0.78) ratios. CONCLUSIONS: This study was designed to be one of hypothesis generation. Diffusion metrics related to kurtosis were found to be more sensitive than conventional diffusivity metrics to early poststroke corticospinal tract microstructural changes and may have potential value in the prediction of motor impairment at 3 months.

Mapping the Orientation of White Matter Fiber Bundles: A Comparative Study of Diffusion Tensor Imaging, Diffusional Kurtosis Imaging, and Diffusion Spectrum Imaging.

BACKGROUND AND PURPOSE: White matter fiber tractography relies on fiber bundle orientation estimates from diffusion MR imaging. However, clinically feasible techniques such as DTI and diffusional kurtosis imaging use assumptions, which may introduce error into in vivo orientation estimates. In this study, fiber bundle orientations from DTI and diffusional kurtosis imaging are compared with diffusion spectrum imaging as a criterion standard to assess the performance of each technique. MATERIALS AND METHODS: For each subject, full DTI, diffusional kurtosis imaging, and diffusion spectrum imaging datasets were acquired during 2 independent sessions, and fiber bundle orientations were estimated by using the specific theoretic assumptions of each technique. Angular variability and angular error measures were assessed by comparing the orientation estimates. Tractography generated with each of the 3 reconstructions was also examined and contrasted. RESULTS: Orientation estimates from all 3 techniques had comparable angular reproducibility, but diffusional kurtosis imaging decreased angular error throughout the white matter compared with DTI. Diffusion spectrum imaging and diffusional kurtosis imaging enabled the detection of crossing-fiber bundles, which had pronounced effects on tractography relative to DTI. Diffusion spectrum imaging had the highest sensitivity for detecting crossing fibers; however, the diffusion spectrum imaging and diffusional kurtosis imaging tracts were qualitatively similar. CONCLUSIONS: Fiber bundle orientation estimates from diffusional kurtosis imaging have less systematic error than those from DTI, which can noticeably affect tractography. Moreover, tractography obtained with diffusional kurtosis imaging is qualitatively comparable with that of diffusion spectrum imaging. Because diffusional kurtosis imaging has a shorter typical scan time than diffusion spectrum imaging, diffusional kurtosis imaging is potentially more suitable for a variety of clinical and research applications.

Simultaneous High-Throughput Conformational and Colloidal Stability Screening Using a Fluorescent Molecular Rotor Dye, 4-(4-(Dimethylamino)styryl)-N-Methylpyridinium Iodide (DASPMI).

Technologies to improve the throughput for screening protein formulations are continuously evolving. The purpose of this article is to highlight novel applications of a molecular rotor dye, 4-(4-(dimethylamino)styryl)-N-methylpyridinium iodide (DASPMI) in screening for the conformational stability, colloidal stability, and subtle pretransition dynamics of protein structures during early formulation development. The measurement of the apparent unfolding temperature (Tm) for a monoclonal antibody in the presence of Tween 80 was conducted and data were compared to the results of differential scanning calorimetry (DSC) measurements. Additionally, measuring the fluorescence intensity of DASPMI as a function of protein concentration shows consistent correlation to the diffusion interaction parameter (kD) for two distinct monoclonal antibody formulations measured by DLS. Lastly, due to the sensitivity of the molecular rotor dye to changes in microviscosity (ηmicro), subtle pretransition dynamics were discernable for two monoclonal antibody formulations that correlate with findings by red-edge excitation shift (REES) experiments. This novel application of molecular rotor dyes offers a valuable and promising approach for streamlining the early formulation development process due to low material consumption and rapid analysis time in a 96-well plate format.

Altered microstructure in temporal lobe epilepsy: a diffusional kurtosis imaging study.

BACKGROUND AND PURPOSE: Temporal lobe epilepsy is associated with regional abnormalities in tissue microstructure, as demonstrated by DTI. However, the full extent of these abnormalities has not yet been defined because DTI conveys only a fraction of the information potentially accessible with diffusion MR imaging. In this study, we assessed the added value of diffusional kurtosis imaging, an extension of DTI, to evaluate microstructural abnormalities in patients with temporal lobe epilepsy. MATERIALS AND METHODS: Thirty-two patients with left temporal lobe epilepsy and 36 matched healthy subjects underwent diffusion MR imaging. To evaluate abnormalities in patients, we performed voxelwise analyses, assessing DTI-derived mean diffusivity, fractional anisotropy, and diffusional kurtosis imaging-derived mean diffusional kurtosis, as well as diffusional kurtosis imaging and DTI-derived axial and radial components, comparing patients with controls. RESULTS: We replicated findings from previous studies demonstrating a reduction in fractional anisotropy and an increase in mean diffusivity preferentially affecting, but not restricted to, the temporal lobe ipsilateral to seizure onset. We also noted a pronounced pattern of diffusional kurtosis imaging abnormalities in gray and white matter tissues, often extending into regions that were not detected as abnormal by DTI measures. CONCLUSIONS: Diffusional kurtosis is a sensitive and complementary measure of microstructural compromise in patients with temporal lobe epilepsy. It provides additional information regarding the anatomic distribution and degree of damage in this condition. Diffusional kurtosis imaging may be used as a biomarker for disease severity, clinical phenotypes, and treatment monitoring in epilepsy.

Serum angiotensin-converting enzyme in sarcoidosis and psoriasis.

Untreated pulmonary sarcoidosis is associated with an increased level of serum angiotensin-converting enzyme (SACE), which is regarded as a valuable method of diagnosing sarcoidosis and measuring the activity of the disease. The level of SACE in cutaneous sarcoidosis or other skin diseases has not been clearly established. We therefore examined SACE in 31 patients with systemic sarcoidosis, including cutaneous manifestations, and 12 patients with isolated cutaneous sarcoidosis. Also, 23 patients with psoriasis were studied. The level of SACE was generally elevated only in patients with untreated systemic sarcoidosis, whereas it was normal in cutaneous sarcoidosis and psoriasis. If the level of SACE is elevated in "isolated" cutaneous sarcoidosis, systemic disease must be strongly suspected.

A semiconductor silicon PIN diode matrix detector for measurement of 133Xe washout in small regional skin areas.

Local variations in microvascularization are expected in lesions and lesion-free skin of patients with pressure sores. To investigate these variations, methods for studies of the regional blood flow rate within small skin areas are needed. Regional blood flow can be estimated by measuring the washout of 133Xe from the tissue. This study describes a 2 x 12 Si PIN diode matrix detector capable of 133Xe detection, and equipped with a collimator to improve the spatial resolution. Thus the regional blood flow in subcutaneous skin areas down to about 2 cm2 can be investigated when the atraumatic epicutaneous labelling technique is used. The capability of the matrix detector and its collimator is described by laboratory investigations. In pilot investigations three normal subjects and three paraplegics with pressure sores were studied. In each individual study the detector matrix was divided into six square areas containing four diode detectors each. Thus six 133Xe disappearance rate constants from adjacent subcutaneous tissue could be determined simultaneously.

Congenital thymic cysts in the neck.

Cervical thymic cysts are rare. Sixty-seven cases are reported in the literature up until 1982. Remnants of thymic tissue in the course of descent may lead to cystic development. The majority of the cases is found in males under 10 years of age, typically on the left side of the neck. The characteristic histological features are thymic tissue with Hassall's corpuscles and cholesterol clefts found in the cyst wall. A preoperative correct diagnosis has never been made. Typically, the templative diagnosis has been a common branchial cyst. An additional case of a thymic cyst is reported, here. Surgical removal was complicated by lesion of the vagal nerve, which has never been described, although the cysts are often adherent to the carotid sheath and vagal nerve.

Experimental pressure induced rupture of the tympanic membrane in man.

The size of the overpressure in the ear canal which causes rupture of the tympanic membrane (TM) in man (rupture pressure, RP) was determined in 90 subjects 7-112 h post mortem in connection with the autopsy. The equipment allowed an overpressure in the ear canal to be applied either gradually or suddenly. In 144 normal TMs it was demonstrated that the tensile strength of the TM increases post mortem. Corrected to the time 0 post mortem, RP of normal TMs ranged 0.5-2.1 kp/cm2, median 1.2 kp/cm2. It was found to be correlated to the age of the patient, i.e. RP decreased with increasing age. No correlation was found between RP and the application speed of the overpressure. Ninety-nine percent of the ruptures were localized to the pars tensa (63% to the anterior part of this structure) and typically had the shape of a minor tear. The RP of 23 TMs with atrophic scars was significantly lower, 0.3-0.8 kp/cm2, and the rupture typically had the shape of a larger defect. The results of this study indicate large intersubject variability of the tensile strength of the human TM. Some individuals are at increased risk of TM rupture at minor overpressures in the ear canal (e.g. during certain watersports, such as diving) which may carry medicolegal implications.

The social aspects of food biotechnology: a European view.

The application of the modern biotechnology to food, notably through the use of GM, has raised concern amongst the European public. Values that underlie this public concern about food biotechnology, include perceptions of: trust, choice, need, and care for a sustainable society and natural balance. Recommendations are advocated for addressing these social aspects, in terms of improving consumer choice, promoting greater public involvement in decision making and achieving a sustainable society. A model of risk analysis for genetically modified organisms (GMOs) and genetically modified food that incorporates this social dimension, through the integration of risk analysis with a social impact analysis is proposed, in order to build greater popular trust into the decision making processes.