Thawing Yedoma permafrost is a neglected nitrous oxide source.

In contrast to the well-recognized permafrost carbon (C) feedback to climate change, the fate of permafrost nitrogen (N) after thaw is poorly understood. According to mounting evidence, part of the N liberated from permafrost may be released to the atmosphere as the strong greenhouse gas (GHG) nitrous oxide (N2O). Here, we report post-thaw N2O release from late Pleistocene permafrost deposits called Yedoma, which store a substantial part of permafrost C and N and are highly vulnerable to thaw. While freshly thawed, unvegetated Yedoma in disturbed areas emit little N2O, emissions increase within few years after stabilization, drying and revegetation with grasses to high rates (548 (133-6286) µg N m-2 day-1; median with (range)), exceeding by 1-2 orders of magnitude the typical rates from permafrost-affected soils. Using targeted metagenomics of key N cycling genes, we link the increase in in situ N2O emissions with structural changes of the microbial community responsible for N cycling. Our results highlight the importance of extra N availability from thawing Yedoma permafrost, causing a positive climate feedback from the Arctic in the form of N2O emissions.

Longitudinal associations of light-intensity physical activity with quality of life, functioning and fatigue after colorectal cancer.

PURPOSE: Evidence from cross-sectional studies suggests that higher levels of light-intensity physical activity (LPA) are associated with better health-related quality of life (HRQoL) in colorectal cancer (CRC) survivors. However, these associations have not been investigated in longitudinal studies that provide the opportunity to analyse how within-individual changes in LPA affect HRQoL. We investigated longitudinal associations of LPA with HRQoL outcomes in CRC survivors, from 6 weeks to 2 years post-treatment. METHODS: Data were used of a prospective cohort study among 325 stage I-III CRC survivors (67% men, mean age: 67 years), recruited between 2012 and 2016. Validated questionnaires were used to assess hours/week of LPA (SQUASH) and HRQoL outcomes (EORTC QLQ-C30, Checklist Individual Strength) at 6 weeks, and 6, 12 and 24 months post-treatment. We applied linear mixed regression to analyse longitudinal confounder-adjusted associations of LPA with HRQoL. RESULTS: We observed statistically significant longitudinal associations between more LPA and better global quality of life and physical, role and social functioning, and less fatigue over time. Intra-individual analysis showed that within-person increases in LPA (per 8 h/week) were related to improved HRQoL, including better global quality of life (ß = 1.67, 95% CI 0.71; 2.63; total range scale: 0-100) and less fatigue (ß = - 1.22, 95% CI - 2.37; - 0.07; scale: 20-140). Stratified analyses indicated stronger associations among participants below the median of moderate-to-vigorous physical activity (MVPA) at diagnosis. CONCLUSION: Higher levels of LPA were longitudinally associated with better HRQoL and less fatigue in CRC survivors up to two years post-treatment. Further prospective studies using accelerometer data are necessary to inform development of interventions targeting LPA.

The immotile cilia syndrome: phase contrast light microscopy, scanning and transmission electron microscopy.

In the immotile cilia syndrome, transmission electron microscopy of the cilia shows abnormalities in the arrangement of the central pairs of tubules and in the dynein arms of the peripheral tubules, or in the radial spokes, We studied four nonrelated children, 9/12, 5, 6, and 6 years old, with situs inversus and a history of chronic sinusitis and bronchitis (Kartagener's syndrome) and four children in the same age group and with the same history, but without situs inversus. Under the phase contrast microscope no motile cilia were seen in the four patients with Kartagener's syndrome and in two of the four other children. Transmission electron microscopy showed aberrations in the cilia (absence of dyneim arms, random orientation of central tubules) in the patients with Kartagener's syndrome. Scanning electron microscopy revealed differences in morphology and arrangement of cilia between patients and controls. In the patients much more mucus was present on the mucosal surface. Furthermore, the cilia were in a state of disorder, with a multidirectional orientation instead of the parallel orientation seen in controls.

Postpartum resolution of glomerular changes in edema-proteinuria-hypertension gestosis.

Complete resolution of glomerular changes in toxemia of pregnancy has been reported to occur as early as 4 weeks postpartum, whereas their persistence for as long as 2 years in some instances has been noted. However, the mechanism of resolution remains obscure. Percutaneous renal biopsy was performed in 22 patients between 10 and 14 days after delivery. These women fulfilled the criteria for toxemia of pregnancy (edema-proteinuria-hypertension gestosis). Biopsy specimens were examined, using light, immunofluorescence and electron microscopy. Semithin sections were studied in view of greater reliability and better relation with further electron microscopic studies. A diffuse increase in mesangial cellularity and matrix was seen in all glomeruli with varying intensity, compatible with mesangium activity, more than endothelial proliferation. So-called capillary occlusions by endothelial swelling were not observed in the biopsies taken 10 days after delivery, but expulsed mesangial cytoplasm could be observed incidentally in the capillary lumen. This phenomenon may explain the wrong interpretation of paraffin sections studied by light microscopy. The presence of immunoglobulins in the glomeruli, seen by immunofluorescence, seems to be nonspecific trapping. In view of experimental studies of mesangium function in macromolecular uptake and processing, it is possible that resolution of the characteristic renal lesions in toxemia is promoted by mesangium activity.

Congenital ichthyosis: concurrent immunodeficiency and atypical T cells.

A patient with congenital ichthyosis and progressive neurologic anomalies showed disturbances in the specific humoral and cellular defense as well as the presence of atypical lymphoid cells in skin and lymph node. The latter resembled the atypical T cells found in mycosis fungoides and Sézary syndrome. The possibility of the presence of either a cutaneous T cell lymphoma or unregulated T cell stimulation leading to concurrent immunodeficiency in this patient is discussed.

Non-Hodgkin's lymphoma of the hard palate.

In the past decades many changes have taken place in the classification of lymphoreticular malignancies. At present two main groups are recognized--Hodgkin's lymphomas and non-Hodgkin's lymphomas. Hodgkin's lymphomas rarely affect the oral cavity. The mouth, especially the soft tissues, is somewhat more frequently involved in cases of non-Hodgkin's lymphoma. There seems to be some predilection for the mucosa of the palate. The present report describes eight patients in whom a swelling of the palatal mucosa led to the diagnosis of non-Hodgkin's lymphoma. The emphasis is on the clinical and microscopic aspects. The present most accepted histologic classifications have been applied and are briefly discussed.

Atypical fibroxanthoma of the skin. Presentation of 5 cases and a review of the literature.

A typical fibroxanthoma is a solitary tumour of the skin, which occurs mostly on sun-exposed areas in elderly people. The diagnosis can only be made with certainty on the typical histological findings, which suggest a bizarre malignant tumour. Although metastasizing tumours are reported in the literature, the authors believe that the true atypical fibroxanthoma is benign. Correct diagnosis obviates the need for unnecessary radical surgery. The possibility of atypical fibroxanthoma should always be considered when a histologically bizarre tumour is found on sun-damaged or irradiation-damaged skin in elderly patients or on previously traumatized sites. In this paper five cases are added to the 346 cases culled from the literature. Electron microscopic investigations in one case demonstrated cells with delicate cytoplasmic fibrils in small bundles. This does not necessarily suggest filaments of myofibroblasts, as has been previously reported.