Development to Term of Fused and Partially Enucleated Mouse Two-Cell Embryos

Contents: After the blastomeres of mouse two-cell embryos were fused by electric pulses within the zona pellucida, one nucleus of the fusion products was removed following the enucleation method described by McGrath and Solter (1983a, 1983b). 38% (196/520) of the fused embryos were enucleated successfully when Whitten's medium was used as enucleation medium and 434 of 1007 (43%) of the embryos when M 2 was used. 30% (47/159) of the partially enucleated embryos cleaved during their in vitro cultivation but only 3% developed to the morula or blasto cyst stage. 20 young (17%) were born after the transfer of 120 fused and partially enucleated two-cell embryos to 8 pseudopregnant recipients. It was shown that fused and partially enucleated two-cell embryos are able to survive and are able to reach adulthood, although their developmental rate is significantly lower than that of control embryos .
Here we report experiments for the examination of the developmental capacity of two-cell mouse embryos partially enucleated after fusion .     

Critically appraising studies reporting assessing diagnostic tests.

Studies that report the sensitivity and specificity of diagnostic tests are susceptible to flaws that can introduce bias and lead to incorrect estimates. This article uses the quality assessment of diagnostic accuracy studies checklist to describe how to appraise a study reporting diagnostic test comparisons critically. The article also contains a glossary of terms that are useful in discussions about diagnostic tests.     

Phosphorus Dynamics in a Luvic Phaeozem After 50 Years of Different P Fertilization

After 50 years of differentiated P fertilization great differences in plant-available P contents between the treatments were measured. However, yield and P uptake varied marginally and only in few plant species these parameters changed significantly. Investigations of P availability, P release and P sorption in different soil depths should show, which phosphorus fractions are important for P supply of agricultural plants in a Luvic Phaeozem. This information can be used for the improvement of fertilization recommendations. A significant decrease in DL-soluble P content in P0 and P15 treatments down to a soil depth of 60cm was measured. Diffusible P content was substantially higher in the P45 treatment in comparison to P0 and P15. Subsoil seems to be an important additional P source. Plant species have a significant influence on phosphorus dynamic. High P sorption in the investigated Luvic Phaeozem, which could not be reduced by excessive P fertilization, may be one of the reasons for low fertilization efficiency in this trial.     

SURVIVAL TIMES FOR CANINE INTRANASAL SARCOMAS TREATED WITH RADIATION THERAPY: 86 CASES (1996–2011)

Sarcomas comprise approximately one‐third of canine intranasal tumors, however few veterinary studies have described survival times of dogs with histologic subtypes of sarcomas separately from other intranasal tumors. One objective of this study was to describe median survival times for dogs treated with radiation therapy for intranasal sarcomas. A second objective was to compare survival times for dogs treated with three radiation therapy protocols: daily‐fractionated radiation therapy; Monday, Wednesday, and Friday fractionated radiation therapy; and palliative radiation therapy. Medical records were retrospectively reviewed for dogs that had been treated with radiation therapy for confirmed intranasal sarcoma. A total of 86 dogs met inclusion criteria. Overall median survival time for included dogs was 444 days. Median survival time for dogs with chondrosarcoma (n = 42) was 463 days, fibrosarcoma (n = 12) 379 days, osteosarcoma (n = 6) 624 days, and undifferentiated sarcoma (n = 22) 344 days. Dogs treated with daily‐fractionated radiation therapy protocols; Monday, Wednesday and Friday fractionated radiation therapy protocols; and palliative radiation therapy protocols had median survival times of 641, 347, and 305 days, respectively. A significant difference in survival time was found for dogs receiving curative intent radiation therapy vs. palliative radiation therapy (P = 0.032). A significant difference in survival time was also found for dogs receiving daily‐fractionated radiation therapy vs. Monday, Wednesday and Friday fractionated radiation therapy (P = 0.0134). Findings from this study support the use of curative intent radiation therapy for dogs with intranasal sarcoma. Future prospective, randomized trials are needed for confirmation of treatment benefits.     

Factors influencing the organic carbon pools in tidal marsh soils of the Elbe estuary (Germany)

Purpose

Soils of tidal marshes play an important role in regional carbon (C) cycles as they are able to store considerable amounts of organic carbon (OC). However, the C dynamics of marsh soils of the Elbe estuary have not been investigated so far. Therefore, the aim of this study was to identify the sources and distribution of soil organic carbon (SOC) and the factors influencing the SOC pools of tidal marshes of the study region.

Materials and methods

In this study, SOC pools were determined in different salinity zones and elevation classes of the estuarine marshes. The amount of initial allochthonous OC was derived from the OC content in fresh sediments. The difference to the recent OC content in the soils was interpreted as autochthonous accumulation or mineralization by microorganisms.

Results and discussion

Young, low marshes of the study sites seem to be predominantly influenced by allochthonous OC deposition whereas the older, high marshes show autochthonous OC accumulation in the topsoils (0–30 cm) and mineralization in the subsoils (30–70 cm). SOC pools of the whole profile depth (0–100 cm) did not significantly differ between elevation classes, but decreased significantly with increasing salinity from 28.3 kg m^?2 in the most upstream site of the oligohaline zone to 9.7 kg m^?2 in the most downstream site of the polyhaline zone. Even though the areal extent of the investigated salinity zones was similar, the SOC mass within 100 cm soil depth decreased from 0.62 Tg (1 Tg = 10¹² g) in the oligohaline zone to 0.18 Tg in the polyhaline zone.

Conclusions

Elevation was found to be one factor influencing the SOC pools of tidal marshes. However, salinity seems to be an even stronger influencing factor reducing the above-ground biomass and, accordingly, the autochthonous OC input as well as the allochthonous input by enhanced mineralization of OC along the course of the estuary. An upstream shift of the salinity zones by sea level rise could, therefore, lead to a reduction of the SOC storage of the estuarine marshes.

     

History and overview of DSHEA

The Dietary Supplement Health and Education Act (DSHEA), enacted in 1994, had two primary goals: to ensure continued consumer access to a wide variety of dietary supplements, and to provide consumers with more information about the intended use of dietary supplements. It accomplished these goals, and more, without changing the fundamental regulatory status of dietary supplements as a category of foods. This article explores the history and reasoning behind the major provisions of the Act and reflects on the impact of each during 15 years of experience under DSHEA.