PEAT-CLSM: A Specific Treatment of Peatland Hydrology in the NASA Catchment Land Surface Model.

Peatlands are poorly represented in global Earth system modeling frameworks. Here we add a peatland-specific land surface hydrology module (PEAT-CLSM) to the Catchment Land Surface Model (CLSM) of the NASA Goddard Earth Observing System (GEOS) framework. The amended TOPMODEL approach of the original CLSM that uses topography characteristics to model catchment processes is discarded, and a peatland-specific model concept is realized in its place. To facilitate its utilization in operational GEOS efforts, PEAT-CLSM uses the basic structure of CLSM and the same global input data. Parameters used in PEAT-CLSM are based on literature data. A suite of CLSM and PEAT-CLSM simulations for peatland areas between 40°N and 75°N is presented and evaluated against a newly compiled data set of groundwater table depth and eddy covariance observations of latent and sensible heat fluxes in natural and seminatural peatlands. CLSM's simulated groundwater tables are too deep and variable, whereas PEAT-CLSM simulates a mean groundwater table depth of -0.20 m (snow-free unfrozen period) with moderate temporal fluctuations (standard deviation of 0.10 m), in significantly better agreement with in situ observations. Relative to an operational CLSM version that simply includes peat as a soil class, the temporal correlation coefficient is increased on average by 0.16 and reaches 0.64 for bogs and 0.66 for fens when driven with global atmospheric forcing data. In PEAT-CLSM, runoff is increased on average by 38% and evapotranspiration is reduced by 19%. The evapotranspiration reduction constitutes a significant improvement relative to eddy covariance measurements.

High-dose treatment with (186)Re-HEDP or (153)Sm-EDTMP combined with amifostine in a rabbit model.

UNLABELLED: The aim of this experimental study was to investigate the myeloprotective potential of amifostine in rabbits receiving high-dose treatment with either (153)Sm-ethylenediaminetetramethylene phosphonate (EDTMP) or (186)Re-hydroxyethylidene diphosphonate (HEDP) and to check for drug interactions impairing the skeletal uptake of these radiopharmaceuticals by amifostine. METHODS: To a total of 24 rabbits, we administered 1,000 MBq of either (153)Sm-EDTMP (n = 12) or (186)Re-HEDP (n = 12). Six animals of each group received 500 mg amifostine intravenously 10-15 min before injection of the radiopharmaceutical, whereas the other 6 animals served as controls. Up to 8 wk after treatment, blood samples were collected every 3-5 d to measure platelet and leukocyte counts. Furthermore, whole-body images were acquired at 3 min, 3 h, and 24 h after injection of the radiopharmaceutical to quantify the skeletal uptake. RESULTS: For (186)Re-HEDP, the mean decrease in platelets was significantly less in the amifostine group (35.5% +/- 2.4%) than in the control group (61.3% +/- 5.4%, P < 0.001). Similar results were found for (153)Sm-EDTMP (36.5% +/- 8.3% vs. 52.3% +/- 14.0%, P < 0.05). No significant differences in leukocyte counts were found for (186)Re-HEDP (75.3% +/- 12.3% in the amifostine group and 72.5% +/- 4.1% in the control group, P > 0.05), whereas rabbits treated with (153)Sm-EDTMP plus amifostine showed a significantly greater decrease in leukocytes (69.2% +/- 10.8%) than did the control group (56.6% +/- 4.0%, P < 0.05). Bone uptake in percentage of initial total whole-body activity was significantly decreased in animals treated with amifostine compared with the control groups for both (186)Re-HEDP (15.8% +/- 3.1% vs. 30.9% +/- 1.9%, P < 0.001) and (153)Sm-EDTMP (31.7% +/- 8.9% vs. 44.0% +/- 6.5%, P < 0.05). CONCLUSION: For amifostine, we found a highly significant cytoprotective effect on platelets but no leukoprotective effect. The latter probably relies on the intrinsic myelotoxicity of high-dose amifostine, which seemed to potentiate the leukodepression of the radiopharmaceuticals. The lower bone uptake in amifostine-treated animals may be caused by the chemical structure of amifostine, which is a potentially complex-forming compound that may be able to displace bisphosphonates from the rhenium- and samarium-bisphosphonate complexes, resulting in altered biodistribution patterns.

[Edematous swelling of the eyelids caused by contact allergy]. / Odematöse Schwellung der Augenlider durch Kontaktallergie.

Cosmetics and ophthalmological topical preparations are the main causes of allergic contact eczema about the eye. In most cases, clinical signs are conjunctival injection, blepharitis, periorbital dermatitis and edema of lids, often combined with itching. Pure edematous swelling of the eyelids should not immediately be blamed on a contact allergy, but sufficiently evaluated to exclude a benign or malignant process of the eyelids, orbita, lacrimal duct and paranasal sinus. We present a patient with pure edematous swelling of the eyelids due to a contact allergy by the sympathicomimetic phenylephrine hydrochloride, an uncommon allergen.

Measurements of radioactivity in environmental samples from the southern Urals.

A region between Chelyabinsk and Ekaterinburg in the Southern Urals has been heavily contaminated due to operational and accidental releases from the first Soviet plutonium production facility Mayak. In 1992 and 1993, the German Federal Office for Radiation Protection organized a measuring campaign involving two Russian institutes to assist with the validation of former Soviet measurement data. The results of this measuring campaign are reported here. Environmental samples were collected from areas affected by significant radioactive releases into the Techa river, which started in 1948, and by fallout from the explosion of a fission product storage tank in 1957. Soil, sediment, water, milk and food samples were independently analysed for 90Sr, 137Cs and plutonium by the three institutes involved. This paper presents data on the present levels of environmental radioactivity. The highest contamination of areas accessible to the local population was found in the vicinity of the Techa river around Muslumovo. Activity concentration of floodplain samples reached up to 37,000 Bq.kg-1 137Cs, 5,600 Bq.kg-1 90Sr and 9.9 Bq.kg-1 Pu. Milk and potatoes from private farms in Muslumovo showed low activity in the range from 0.7 Bq.kg-1 to 25 Bq.kg-1 90Sr. The results of the three independent measurement teams showed sufficient agreement. One Russian laboratory obtained plutonium activities that exceeded the results of the other laboratories by about 20%. Contrary to the International Chernobyl Project, there was no overestimation of 90Sr activities in the Russian analyses. Therefore, the validity of earlier data sets acquired with same methodology and quality control can be considered a valuable basis for further assessments and for dose reconstruction in epidemiological projects.

Excessive basement membrane material production by epithelial tumors induced by dimethylnitrosamine in rat kidneys.

In an experimental series of preneoplastic lesions and neoplasms induced in the rat kidney by dimethylnitrosamine, four of the 54 tumors showed particular morphological features that allowed them to be grouped separately. The leading characteristic of these lesions was an abundant PAS-positive matrix in which the tumor cells were embedded. The demonstration of variable amounts of laminin, heparan sulfate proteoglycan, collagen types IV and V in the tumor matrix provided circumstantial evidence that it consisted of basement membrane material. Since the tumor cells were in intimate contact with the matrix and no fibroblasts were present, it was assumed that the matrix was a product of the tumor cells. Until now, no similar renal tumors have been described in laboratory animals and no human equivalent is known.

Morphology and proliferation kinetics of early tumor stages induced by dimethylnitrosamine in rat kidneys.

A total of 49 dimethylnitrosamine (DMN)-induced rat renal cell tumors were analyzed and classified cytomorphologically at an early stage of development. Of these, 17 were basophilic-tubular tumors, two of which showed a direct transition to proximal tubules of the P3-segment; 21 lesions were vacuolated and contained glycogen; these were defined cytomorphologically as a separate tumor type the histogenetic derivation of which from the collecting duct system was established by documentation of a direct transition. Morphological similarities point to the lipid-storing variant of the basophilic tumor, but a carcinoma of the ducts of Bellini is another possible human equivalent of this tumor type. Another seven lesions were clear and granular cell tumors. In two of these a direct transition from the collecting duct system was found, thus confirming that this only recently established origin of experimentally induced rat renal clear cell tumors also applies to lesions induced by DMN. The proliferation kinetics of DMN-induced lesions were studied in autoradiograms after pulse-labeling with tritiated thymidine. The basal proliferation of these early tumor stages displayed a marked proliferative advantage over the normal parenchyma. The lesions were still subject to physiological growth stimulation as determined by 3H-TdR-continuous-labeling with osmotic mini-pumps following unilateral nephrectomy. However, compared with normal kidney parenchyma, the 3H-TdR-labeling index of the lesions was even higher indicating a response modification during early neoplasia.

[The morphology of chemically induced kidney tumors of the rat as a model for the typing of human kidney tumors]. / Zur Morphologie chemisch induzierter Nierentumoren der Ratte als Modell für die Typisierung von menschlichen Nierentumoren.

1. 109 renal cell carcinomas were produced in 92 Wistar rats by a single dose of 80 mg/kg diethylnitrosamine 4, 16, 24 h after partial liver resection. These tumors showed a wide variety of morphological appearances, comparable with different types of human renal cell carcinomas, as proposed by THOENES et al. in a new cytomorphological classification. However, there were striking differences as to the incidence of the individual tumors types. Whereas clear cell tumor prevailed in human they were very rare in the animal experiment. 2. 54 renal cell carcinomas were produced in 105 rats by a single dose of 30 mg/kg dimethylnitrosamine after a low-protein diet of 5 days. Also in this experiment a variety of different tumor types resulted. Already in early "tubular lesions" a strikingly elevated thymidine labelling was found, in contrast to the surrounding regular tubular epithelial cells. Moreover, topographical relations of various tumor cell types to different segments of the nephron became evident. Besides a fair number of basophilic tumors with transition into proximal tubular epithelial cells, a large number of tumors showing abundant, typically vacuolated cytoplasm became evident. These tumor cells showed in general the highest labelling index with thymidine. They apparently are related to the distal nephron and possibly constitute neoplasms of the collecting ducts, compatible with otherwise rare ductus Bellini carcinomas. Concluding, the heterogeneity concerning tumor cell types and labelling indices has to be emphasized, whereby the latter also, appear to be dependent on the vascular blood supply.