ULTRASTRUCTURAL LOCALIZATION OF CALCITONIN IN THE PARAFOLLICULAR CELLS OF PIG THYROID GLAND WITH CYTOCHROME c-LABELED ANTIBODY FRAGMENTS

Parafollicular cells in mammalian thyroid glands are thought to be responsible for the secretion of calcitonin. In this study, calcitonin was localized in pig thyroid gland by an indirect immunocytochemical technique using rabbit antiserum directed against synthetic porcine calcitonin for the first step, and sheep Fab fragments prepared against rabbit Fab and coupled to cytochrome c for the second step. The antigenic determinants of calcitonin were present only in the parafollicular cells, whose secretory granules were heavily labeled. Labeling of the cytoplasmic matrix is thought to indicate a possible leakage of the polypeptide from the granules. A striking observation was the complete absence of labeling in the cisternae of the rough-surfaced endoplasmic reticulum and of the Golgi apparatus. It is concluded that the secretory granules of parafollicular cells contain calcitonin; the mechanism of synthesis of this peptide is not clearly understood

Ultrastructural localization of intracellular antigen using enzyme-labeled antibody fragments

The efficiency of small enzyme-labeled tracers for the demonstration of intracellular antigen was investigated in tissues fixed with picric acid-formaldehyde. The influence of fixation on the immunological activity was tested in vitro by radial immunodiffusion. The experimental model consisted of newborn pig jejunum after absorption of ferritin from the intestinal lumen. Ferritin was located after 1 hr in vacuoles scattered in the cytoplasm of the absorptive cells and represented an easily recognizable intracellular antigen. After immunohistochemical treatments with antiferritin preparations, the distribution of labeling enzyme reaction product was examined by morphometry. The ratio of the labeled volume to the total volume of vacuoles containing ferritin indicated the degree of specific labeling of the antigen. In both direct and indirect methods, the degree of labeling was low when enzyme-labeled immunoglobulin G was the tracer. With antigen binding fragments (Fab), the labeling was significantly increased. In the indirect method, the degree of labeling was influenced by the first-step reagents. Onlywhen the serum titer was optimum was a high degree of labeling obtained. With antigen binding fragments or papain-digested serum the effect of the titer was negligible and maximum labeling was achieved. In both methods, with peroxidase as the labeling enzyme, a diffuse nonspecific deposition of reaction product was observed. This could be avoided by using cytochrome c instead

2008 Farm Bill Decision Tools

This article describes a tool developed by Oklahoma Cooperative Extension Service to aid in the decision to enroll in a new commodity program contained in the 2008 Farm Bill. Producers have the option to enroll in the Direct Counter-Cyclical Payment (DCP) program or the Average Crop Revenue Election (ACRE) program. The choice between ACRE and DCP is an important decision for farm profitability. The ACRE program is complex, and the calculation of potential ACRE payments can be quite daunting. The ACRE decision tool was developed to perform the calculations necessary to estimate potential ACRE payments for the 2009-2012 crop years

2008 Farm Bill Decision Tools

This article describes a tool developed by Oklahoma Cooperative Extension Service to aid in the decision to enroll in a new commodity program contained in the 2008 Farm Bill. Producers have the option to enroll in the Direct Counter-Cyclical Payment (DCP) program or the Average Crop Revenue Election (ACRE) program. The choice between ACRE and DCP is an important decision for farm profitability. The ACRE program is complex, and the calculation of potential ACRE payments can be quite daunting. The ACRE decision tool was developed to perform the calculations necessary to estimate potential ACRE payments for the 2009-2012 crop years

CFS shear walls braced with steel sheets: proposal of seismic design criteria for the next EN1998

The paper describes a specific study performed to include seismic design criteria for cold-formed steel (CFS) steel-sheathed shear walls in the next version of the European earthquake standard EN1998. In particular, the study aims to extend the applicability of the Effective Strip Method (ESM), given in North American standard AISI S400 to the next European standard EN1998. The ESM is an alternative to the tabulated method given by AISI S400 for the evaluation of the shear resistance of steel-sheathed cold-formed steel (SSCFS) shear walls and it is allowed to use in USA & Mexico for predefined wall configurations. In the presented study the ESM is applied to additional available experimental results of walls tested in Canada, in order to further prove its validity for wall configurations different from those used for its initial calibration. Moreover, the ESM is applied following the European approach, to make its use possible in context of European seismic design methodology. The main conclusion is that the ESM could be appropriate for the evaluation of resistance of SSCFS shear walls and it could be implemented in the next version of EN1998, considering some modifications

Numerical modelling of CFS two-storey sheathing-braced building under shaking-table excitations

The recent seismic events have highlighted the need of tools for predicting the performance until collapse and hence assisting to minimize the damages and losses. A European project, named ELISSA, has been recently finished, in which the University of Naples Federico II has explored the seismic behaviour of a Cold Formed Steel (CFS) full-scale two-storey building, via shake-table tests on bare structure and complete construction phases of specimen. Starting from experimental results, advanced numerical models have been developed using the OpenSees software, which consider both structural and non-structural elements and their contribution to the response. The comparison between experimental and numerical results showed that the proposed approach can capture the seismic behaviour of tested building, with acceptable prediction of the response in terms of inter-storey drift peaks and time history if structural and non-structural components are explicitly considered. A further task showed that the earthquake sequence effect can affect the results and it should be taken into account for a better numerical prediction