[Surgery of papillary thyroid microcarcinoma]. / Chirurgie papillärer Mikrokarzinome der Schilddrüse.

BACKGROUND: Different countries are currently reporting a substantial increase in the incidence rates of papillary thyroid microcarcinoma (PTMC). OBJECTIVE: Presentation of diagnosis and surgical therapy of PTMC and discussion of a more conservative approach, such as active surveillance. MATERIAL AND METHODS: Overview of the current guidelines from different countries and analysis of recent publications reporting the results of active surveillance of PTMC from Japan, Korea and the USA. RESULTS: The majority of international guidelines for PTMC recommends thyroid lobectomy as the gold standard. Active surveillance as an alternative procedure is described in the Japanese guidelines (JSTS/JAES). Present surveillance studies including more than 1700 patients report a tumor growth in 8-14% of the cases during a median follow-up of up to 75 months. Tumor growth and lymph node metastases are detected most frequently in younger patients (below 40-50 years). CONCLUSION: Active surveillance might serve as an alternative treatment option for older patients with PTMC. Since the median follow-up periods are currently not long enough, it seems difficult to draw definite conclusions of this procedure right now.

Land use change impacts on floods at the catchment scale: Challenges and opportunities for future research.

Research gaps in understanding flood changes at the catchment scale caused by changes in forest management, agricultural practices, artificial drainage, and terracing are identified. Potential strategies in addressing these gaps are proposed, such as complex systems approaches to link processes across time scales, long-term experiments on physical-chemical-biological process interactions, and a focus on connectivity and patterns across spatial scales. It is suggested that these strategies will stimulate new research that coherently addresses the issues across hydrology, soil and agricultural sciences, forest engineering, forest ecology, and geomorphology.

Soil organic matter as sole indicator of soil degradation.

Soil organic matter (SOM) is known to play vital roles in the maintenance and improvement of many soil properties and processes. These roles, which largely influence soil functions, are a pool of specific contributions of different components of SOM. The soil functions, in turn, normally define the level of soil degradation, viewed as quantifiable temporal changes in a soil that impairs its quality. This paper aims at providing a generalized assessment of the current state of knowledge on the usefulness of SOM in monitoring soil degradation, based on its influence on the physical, chemical and biological properties and processes of soils. Emphasis is placed particularly on the effect of SOM on soil structure and availability of plant nutrients. Although these properties are discussed separately, the soil system is of dynamic and interactive nature, and changes in one property will likely affect other soil properties as well. Thus, functions of SOM almost always affect various soil properties and processes and engage in multiple reactions. In view of its role in soil aggregation and erosion control, in availability of plant nutrients and in ameliorating other forms of soil degradation than erosion, SOM has proven to be an important indicator of soil degradation. It has been suggested, however, that rather than the absolute amount, temporal change and potential amount of SOM be considered in its use as indicator of soil degradation, and that SOM may not be an all-purpose indicator. Whilst SOM remains a candidate without substitute as long as a one-parameter indicator of soil degradation is needed, narrowing down to the use of its labile and microbial components could be more appropriate, since early detection is important in the control and management of soil degradation.

(Bio-)remediation of VCHC contaminants in a Technosol under unsaturated conditions.

The remediation of dense non-aqueous phase liquids has always been a concern of both public and scientific interest groups. In this research work a modified physical concept of (bio)remediation of a volatile chlorinated hydrocarbon (VCHC) contamination was elaborated under laboratory conditions and modeled with HYDRUS-2D. In field dechlorination is influenced by both physicochemical and hydraulic properties of the substrate, e.g. texture, pore size distribution, pore liquid characteristics, e.g. viscosity, pH, surface tension, and dependent on the degree of saturation of the vadose zone. Undisturbed soil cores (100 cm³) were sampled from a Spolic Technosol. Considering hydraulic properties and functions, unsaturated percolation was performed with vertically and horizontally structured samples. VCHC concentrations were calculated prior, during, and after each percolation cycle. According to laboratory findings, microemulsion showed the most efficient results with regard to flow behavior in the unsaturated porous media and its accessibility for bacteria as nutrient. The efficiency of VCHC remediation could be increased by the application of a modified pump-and-treat system: the injection of bacteria Dehalococcoides ethanogenes with microemulsion, and extraction at a constant matric potential level of -6 kPa. Achieved data was used for HYDRUS-2D simulations, modeling in situ conditions, demonstrating the practical relevance (field scale) of performed unsaturated percolation (core scale), and in order to exclude capillary barrier effects.

Hemoglobin A1c levels in children and adolescents with diabetes mellitus.

Hemoglobin A1c (HbA1c) was measured as an indicator of glucose control in 180 children and adolescents with diabetes mellitus who received two daily injections of insulin as part of a highly structured treatment program. A total of 426 HbA1c determinations was made in the group of 180 patients. HbA1c values were elevated in most patients despite the aggressive treatment. The HbA1c level was very elevated at diagnosis, fell to near normal after 60-90 days of insulin therapy, increased gradually, and reached a plateau after approximately 4 yr duration (at about twice the level in normal subjects) (mean +/- SEM, 10.0 +/- 0.2% and 5.34 +/- 0.07%, respectively). Mean insulin dose (U/kg/24 h) paralleled both HbA1c and duration of diabetes. The relationship between endogenous insulin secretion and glucose control was examined in those patients with diabetes for longer than 5 yr. Patients were separated into three groups based on HbA1c levels: those with HbA1c less than 9% (N = 22), between 9 and 11% (N = 26), and greater than 11% (N = 28). Serum C-peptide and glucose concentrations were measured 2 h after a standard breakfast in those patients in the "low" and "high" HbA1c groups (mean HbA1c values 8.2% and 12.7%, respectively). C-peptide was detectable in all patients and the mean C-peptide levels did not differ significantly in the two groups, although postprandial glucose concentrations were significantly lower in the "low" HbA1c group (means +/- SEM, 96 +/- 11 and 211 +/- 21 mg/dl, respectively; P less than 0.001).