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Regulatory guidelines for pharmaceutical toxicity studies recommend using one dose near the maximum tolerated. At that level significant toxicities may occur, leading to systemic stress and secondary immune suppression which can be difficult to differentiate from a primary drug effect. Therefore, there is a need for a biomarker of stress applicable to toxicity studies. This study evaluated urinary corticosterone as a biomarker, using as a pharmacologic stressor fenitrothion, which was previously shown not to cause primary immune suppression. Rats were administered fenitrothion orally at 20 and 30 mg/kg daily for 2 or 8 days, with matched vehicle controls (n = 6/group). Urine was collected for 6 and 24 h, before treatment and on Day 2 and Day 8. Urine was assayed for corticosterone, separately for the first 6 h of collection and for the whole 24 h sample. Animals were euthanized on Day 3 or Day 9 and lymphoid tissue samples were collected, weighed and examined histologically. Treated rats showed neurologic signs following treatment. Findings also included time- and dose-dependent decreases in body weight and spleen and thymus weight decreases supra-proportional to body weight on Day 9. Histologic changes were mild at a dose of 20 mg/kg, but significant at 30 mg/kg, consisting of lymphocytolysis at Day 3 and lymphoid depletion at Day 9. Urine corticosterone levels were increased on Day 2 and Day 8, in the 6-h samples, but not the 24-h ones, at both dose levels. Based on the results, urine corticosterone appears to be a sensitive biomarker of systemic stress caused by fenitrothion. Other chemical stressors should be evaluated in a similar manner in order to fully validate urine corticosterone measurement as a stress biomarker.

The sous vide method of food processing involves placing raw or partially cooked products in a pouch, removing the air, sealing, cooking and then chilling the product for an extended time. This method provides an ideal environment for growth of some pathogenic bacteria. The purpose of this study was to determine the microbiological quality of a ground pork product using the sous vide method of processing. Patties prepared with and without soy hulls were cooked at 62 or 76C and stored chilled for 0, 1, 2 and 3 weeks. Samples were monitored for Listeria spp. with aerobic plate counts (APCs) and coliform counts also being determined. Moisture, pH and fat content of ground pork were measured. For the raw product, no statistically significant difference was found for coliforms, APCs or pH for the 12 trials of the experiment. Listeria spp. were not isolated from the raw product. Statistically significant differences were only found for fat and moisture. No coliforms were found in cooked patties or in cooked patties stored over the 3-week period. However, statistically significant differences were noted for APCs. Over the 3-week storage period, pork patties prepared with and without soy hulls and cooked at the higher temperature had lower APCs than patties cooked at the lower temperature. Pork patties cooked at the lower temperature had unacceptable levels of APCs for all weeks of chilled storage. Sous vide products made under carefully controlled conditions can be of good microbiological quality, even when stored up to 3 weeks.

We propose the use of recently developed technique of circular intensity differential scattering (CIDS), as extended to the soft x-ray region of the spectrum (16 eV to 500 eV), to study the higher order organization of the eukaryotic chromosome. CIDS is the difference in scattering power of an object when illuminated by right circularly polarized vs. left circularly polarized electromagnetic radiation of arbitrary wavelength. CIDS has been shown to be a very sensitive measure of the helical organization of the scattering object, e.g., the eukaryotic chromosome. Preliminary results of measurements of samples of bacteriophages and octopus sperm done at SRC, Wisconsin, show the technique to be very sensitive to the dimensional parameters of the particles interrogated by circularly polarized light.© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Synchrotron radiation (SR) from modern electron storage rings is highly linearly polarized and more intense than conventional vacuum ultraviolet continuum sources. These unique properties make SR ideal for construction of a vacuum ultraviolet circular dichroism (CD) instrument. We report the first use of SR for CD measurements and describe the instrumental setup. These measurements were carried out in the wavelength range 1325–2050 A on (+)-3-methylcyclopentanone at the Synchrotron Radiation Center of the University of Wisconsin-Madison. The signal to noise ratio, and therefore the resolution, was the best ever obtained for CD measurements in this wavelength range. This resulted in the observation of new structure and dramatic peak height changes in the CD spectrum. In addition, these measurements showed that the extension of CD measurements to higher energies is possible through the use of synchrotron radiation.

This case example describing the organizational behavior of the staff in an agency serving the deaf is used to illustrate some of the issues and problems which human service providers face in cross-cultural settings. Staffing, internal coordination and control, and external relationships are the three organizational features selected for analysis. It is suggested that an examination of an agency's internal operation is critical to a thorough evaluation of its service delivery and that by considering the agency as an open social system the impact of the social environment can be identified. Communication issues are especially critical in the agency studied but can be seen as representative of the major problems in cross-cultural service delivery.

Vacuum ultraviolet natural and magnetic circular dichroism measurements have added significantly to our knowledge of the geometric and electronic structure of molecules and have provided a better understanding of the correct approach for theoretical calculations. In this review, I define natural and magnetic circular dichroism, and discuss information obtained with these techniques. The instrumentation for vacuum ultraviolet natural and magnetic circular dichroism is reviewed, from its beginning with conventional sources to the present time use of synchrotron radiation. The future possibilities and challenges for these measurements are examined with particular reference to making measurements to higher energies.

Since synchrotron radiation is intense, highly linearly polarized, a spectral continuum and collimated, it is ideal (necessary) for magnetic and natural circular dichroism measurements in certain regions of the spectrum. What these regions are, the importance of the measurements and considerations in instrumental design which preserve the ideal properties of synchrotron radiation are discussed. Then the design, present status and future plans are reviewed for each functioning instrument. Finally the instrumental design challenges of the future are surveyed.

Substances which rotate the plane of polarization of linearly polarized light are called optically active. The optical rotation occurs due to unequal responses to left and right circularly polarized radiation. Circular dichroism spectroscopy measures the difference in absorption between left and right circularly polarized light (usually expressed as the difference in molar extinction coefficient, eL-eR, or absorbance, AL-AR) as a function of wavelength.