Immunofluorescent localization of human pituitary luteinizing hormone

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/32182/1/0000238.pd

Competition for the in vitro binding of radioiodinated human follicle-stimulating hormone in reptilian, avian, and mammalian gonads by nonmammalian gonadotropins

Radioiodinated human FSH (125I-hFSH) was used to study the specificity of the gonadotropin binding sites of various reptilian, avian, and mammalian gonadal tissues by examining competitive interactions with several nonmammalian gonadotropins. All preparations of nonmammalian gonadotropins showed some activity in these radioligand assays, but wide variations in activities were evident depending on the source of the tissue and source of the hormone. Several cases of marked species specificity in binding were apparent: Nonmammalian hormones were relatively inactive with porcine granulosa cells; frog and snake hormones were relatively inactive in turtle tissues; and frog hormones were essentially inactive in avian tissues. FSH-LH specificity of binding determined with hormones of nonmammalian origin differed significantly from that previously described with the aid of mammalian gonadotropins. In particular, when tested with some tissues, three preparations of LH, from the turkey, sea turtle, and frog, were in some cases more active in competing for 125I-hFSH binding than preparations of FSH from the same species; this activity could not be readily accounted for by FSH contamination. These comparative data demonstrate the existence of considerable overlap in the binding characteristics of some species of FSH and LH; the observed differences probably reflect evolutionary changes in both gonadotropin binding sites and in the structure of the gonadotropins.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/21644/1/0000028.pd

Hapten-radioimmunoassay: A general procedure for the estimation of steroidal and other haptenic substances

Hapten-radioimmunoassay may be used for sensitive and specific quantitation of low molecular weight substances which can be made immunogenic by conjugation to a protein, This method, which involves radioiodination of the protein-portion of the conjugate, has been used for quantitation of non-conjugated estrogenic steroids.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/32963/1/0000346.pd

Computer program sequence for analysis and summary of radioimmunoassay data

A sequence of three programs is described for efficient design and analysis of radio-immunoassays. The first program designs the assay; the second program analyzes all available data according to the organizational base provided by the first program; and the third program summarizes the results of several assays in either tabular or graphical form. The analysis program uses a logit response-log dose transformation to obtain a linear inhibition curve for all preparations assayed at multiple levels. The curves are subjected to a weithted, least squares, regression analysis. All curves are tested for linearity and parallelism with the curve chosen as standard, and a weighted mean potency estimate with error limits is computed for all preparations run at single or multiple dose levels with any degree of replication.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/34088/1/0000369.pd

Broad-Scale Patterns of Late Jurassic Dinosaur Paleoecology

There have been numerous studies on dinosaur biogeographic distribution patterns. However, these distribution data have not yet been applied to ecological questions. Ecological studies of dinosaurs have tended to focus on reconstructing individual taxa, usually through comparisons to modern analogs. Fewer studies have sought to determine if the ecological structure of fossil assemblages is preserved and, if so, how dinosaur communities varied. Climate is a major component driving differences between communities. If the ecological structure of a fossil locality is preserved, we expect that dinosaur assemblages from similar environments will share a similar ecological structure.This study applies Ecological Structure Analysis (ESA) to a dataset of 100+ dinosaur taxa arranged into twelve composite fossil assemblages from around the world. Each assemblage was assigned a climate zone (biome) based on its location. Dinosaur taxa were placed into ecomorphological categories. The proportion of each category creates an ecological profile for the assemblage, which were compared using cluster and principal components analyses. Assemblages grouped according to biome, with most coming from arid or semi-arid/seasonal climates. Differences between assemblages are tied to the proportion of large high-browsing vs. small ground-foraging herbivores, which separates arid from semi-arid and moister environments, respectively. However, the effects of historical, taphonomic, and other environmental factors are still evident.This study is the first to show that the general ecological structure of Late Jurassic dinosaur assemblages is preserved at large scales and can be assessed quantitatively. Despite a broad similarity of climatic conditions, a degree of ecological variation is observed between assemblages, from arid to moist. Taxonomic differences between Asia and the other regions demonstrate at least one case of ecosystem convergence. The proportion of different ecomorphs, which reflects the prevailing climatic and environmental conditions present during fossil deposition, may therefore be used to differentiate Late Jurassic dinosaur fossil assemblages. This method is broadly applicable to different taxa and times, allowing one to address questions of evolutionary, biogeographic, and climatic importance

Hormonal regulation of ovarian cellular proliferation

The steroid hormone estradiol, and the glycoprotein hormones follicle-stimulating hormone (FSH) and luteinizing hormone (LH), are known to be essential for the growth and differentiation of follicles in the ovary. The present study was conducted to determine quantitatively the effects of estradiol, FSH and LH on proliferation of different ovarian cell types (granulosa and theca cells). The immature female hypophysectomized rat sequentially primed with estradiol, FSH and LH was used as the experimental model. Proliferation was assessed by examining changes in total DNA, incorporation of 3H-thymidine into DNA and labeling index in specific cell types. Estradiol and FSH each acted on follicies at different stages of development to stimulate proliferative activity of both granulosa and theca cells. Continued administration of either hormone caused a decrease in the proliferative activity of both cell types. These observations have been interpreted to indicate that estradiol and FSH can each alter the length of the specific phases of the cell cycle. A luteinizing dose of LH caused a cessation of proliferation in luteinizing granulosa cells while stimulating a limited proliferation of theca cells. Absence of the appropriate hormonal stimulus caused both granulosa and theca cells to stop proliferating and the follicles to undergo atresia. These results indicate that, depending upon the state of differentiation of granulosa and theca cells, estradiol, FSH and LH can stimulate or inhibit the ability of these cells to proliferate.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/22604/1/0000154.pd

A specific, non-chromatographic radioimmunoassay for human plasma cortisol

A radioimmunoassay technique has been developed for the measurement of cortisol in a single methylene chloride extract of human plasma without chromatography. The antiserum, obtained by immunizing rabbits with cortisol-3-carboxymethyl-oxime conjugated to bovine serum albumin, had a high affinity (KA = 1.8 x 109l/mole) and capacity (2.3 x 10-6 moles/L undiluted serum) for cortisol. The minimum detectable amount determined at the lower 95% confidence limit of the buffer control tubes was 8.3 +/- 4.7 pg/tube and a log dose -- logit response standard curve was linear between 20 pg and 20 ng/tube. The antiserum was highly specific for cortisol with only corticosterone, cortisone, 11-deoxy-cortisol and 21-deoxycortisol showing significant cross-reaction (12.4, 6.6, 3.8 and 3.1%, respectively). The cross-reaction for the other tested naturally occurring and synthetic steroids did not exceed 1%. Regression analysis of cortisol concentration estimates obtained on 20 samples before and after Sephadex LH-20 column chromatography gave a coefficient of correlation (r) of 0.995 and a regression coefficient (b) of 1.04. Recovery of cortisol added to plasma samples was quantitative. The intra-assay error was 8.5% and the inter-assay error averaged 5.7%. The method is simple requiring a single solvent extraction of plasma, therefore permitting large numbers of samples to be handled efficiently by a single technician.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/21962/1/0000371.pd

Integration of the biophysical and social sciences using an indicator approach: Addressing water problems at different scales

To be operationally sustainable, any system of environmental management needs to be based on a truly holistic assessment of all of the relevant factors influencing it. This is of course a daunting task, demanding as it does detailed and reliable data, not only from both the physical and social sciences, but also incorporating some representation of that part of knowledge which could be described as non-scientific. This could be said to include the uncertainties of market forces and political will, as well as traditional knowledge systems, and artistic representation. Recognising the limitations of our own knowledge system is important if we are to make progress in the achievement of sustainability. The development of less deterministic models is a step forward in that direction. This paper provides some discussion on the challenges associated with the integration of data from different disciplines, and the application of that data at different scales. Alternative approaches to the assessment of water resources for policy making are highlighted, and the validity of using such assessments at different scales is discussed. Using the Water Poverty Index as illustration, examples are provided of how an integrated assessment framework can be used to provide consistency and transparency in decision-making, and how this can, in practice, be applied at a variety of scales