Showing papers by "University of Oregon published in 1975"

Chlorophyll arrangement in a bacteriochlorophyll protein from Chlorobium limicola

Abstract: The three-dimensional structure of a chlorophyll-containing protein has been determined by X-ray crystallography and shown to consist of three identical subunits, each containing a core of seven bacteriochlorophylls arranged in an irregular fashion and enclosed within an envelope of protein.

Confidence Interval Estimation of Survival Probabilities for Censored Data

Abstract: The likelihood ratio method for confidence interval estimation of survival or life-time probabilities is investigated for censored data. This approach depends on a constrained product-limit estimator for the survival function. The likelihood method is compared with two alternative methods based on normal approximations to the product-limit estimator for several cases of uncensored and randomly censored samples. The methods are generalized for the ratio of two survival probabilities.

The binding of deoxycholate, Triton X-100, sodium dodecyl sulfate, and phosphatidylcholine vesicles to cytochrome b5.

Abstract: Cytochrome b5 is composed of two domains that can be isolated after tryptic cleavage as two polypeptide fragments. One fragment is globular and hydrophilic and contains the heme; the other fragment is rich in hydrophobic amino acids and is essential for recombination of cytochrome b5 with microsomal membranes (Ito, A., and Sato, R. (1968), J. Biol. Chem. 243, 4922; Spatz, L., and Strittmatter, P. (1971), Proc. Nat. Acad. Sci. U.S. 68, 1042). Equilibrium dialysis and sedimentation equilibrium measurements of the binding of deoxycholate, Triton X-100 and dodecyl sulfate show that neither intact cytochrome b5 nor its proteolytic fragments possess high affinity binding sites for any of these amphiphiles. However, each detergent binds to the protein in a highly cooperative manner at concentrations near the critical micelle concentration. Binding measurements using the separated tryptic fragments show that deoxycholate and Triton X-100 (both nondenaturing detergents) bind to the hydrophobic fragment to the same extent as to intact cytochrome b5, and not at all to the polar fragment. Sodium dodecyl sulfate (a denaturing detergent) is bound to both tryptic fragments, but 70% of the detergent is bound to the hydrophobic fragment although it comprises only 30% of the protein mass. Less detailed measurements were made with synthetic and natural phosphatidylcholines, and show that the intact protein is quantitatively incorporated into phosphatidylcholine vesicles, but that no interaction with the polar fragment occurs. These results are interpreted in terms of the hydrophobic domain of cytochrome b5 having a diffuse hydrophobic surface that can act as a nonspecific nucleus for the formation of a micelle with a variety of amphiphilic substances. This domain of the molecule will insert into any available hydrophobic environment, whether it be detergent micelles, synthetic phospholipid vesicles, or the microsomal membrane. The incorporation of cytochrome b5 into the microsomal membrane is only a specialized case of the general property.

Impact of clear-cutting and road construction on soil erosion by landslides in the western Cascade Range, Oregon

Abstract: The H.J. Andrews Experimental Forest can be divided into two zones of approximately equal area, each with strikingly different susceptibilities to erosion by rapid soil movements. A stable zone occurs at elevations above 900 to 1,000 m in terrain underlain by lava-flow bed rock. Since logging and road cutting began in 1950, only two small road-related slides have taken place in the stable zone. In contract, the unstable zone, located at elevations below 1,000 m and underlain by altered volcaniclastic rock, has been the site of 139 slides during the same period. Slide erosion from clear-cut areas in the unstable zone has totaled 6,030 cu m/sq km, or 2.8 times the level of activity in forested areas of the unstable zone. Along road rights-of-way, slide erosion has been 30 times greater than on forested sites in the unstable zone; however, only about 8 percent of a typical area of deforested land in the unstable zone is in road right-of-way. At comparable levels of development (8 percent roads, 92 percent clear-cut), road right-of-way and clear-cut areas contribute about equally to the total impact of management activity on erosion by landslides in the unstable zone. The combined management impacts in the unstable zone (assuming 8 percent road right-of-way and 92 percent clear-cut) appear to have increased slide activity on road and clear-cut sites by about 5 times relative to forested areas over a period of about 20 yr.

Estrogens in fetal and maternal plasma of the rhesus monkey

Abstract: The quantities of estrone and estradiol were determined by radioimmunoassay in maternal and fetal plasma of the rhesus monkey from day 59 to 163 of gestation. A two way analysis of variance of data classified according to fetal sex and 3 pooled gestational ages for each hormone and for mother or fetus (4 analyses) revealed significant elevations in fetal estradiol and maternal estrone concentrations with age. All other comparisons were not significant by these analyses. The concentrations of estradiol were greater in maternal than in fetal plasma [769 +/- 64 (SE) pg/ml, N = 63 VS 57 +/- 6 (SE) pg/ml, N = 77, P less than 0.01] by a t test. Estrone, on the other hand, was similar in mother and fetus [265 +/- 30 (SE) pg/ml, N = 60 vs 318 +/- 37 (SE) pg/ml, N = 73, P greater than 0.05]. No sex differences in the concentrations of these hormones were observed except in the fetus after 150 days of gestation. At this time plasma from female fetuses contained significantly more estradiol than plasma from male fetuses [118 +/- 20 (SE) pg/ml, N = 7 vs 61 +/- 10 (SE) pg/ml, N = 19, P less than 0.01]. Except for estradiol in female fetuses, the concentrations of estrogen were significantly higher in the umbilical vein than in the umbilical artery, an indication that the placenta is a major source of fetal estrogen in this species. Estrone and estradiol were significantly correlated in both the fetal and maternal circulation, r = 0.58, P less than 0.001 and r = 0.39, P less than 0.01 respectively. The results provide quantitative data about the estrogen miliue in which the monkey fetus develops and suggest mechanisms for controlling fetal estrogen in this species.

Social Anxiety and Self-Evaluation of Interpersonal Performance

Abstract: High and low socially anxious men participated in two brief conversations with female confederates. Each subject rated his own and other conversations on social skill, anxiety, and female's respons...

Evidence that insect dorsal unpaired medican (DUM) neurons are octopaminergic.

Abstract: The dorsal unpaired median neuron innervating the extensor tibiae (DUMETi) of locusts and grasshoppers, as well as some other DUM neurons, cause long-term inhibition of the slow intrinsic rhythm of contraction of the muscle by releasing a neurohumoral agent. Large, (600 - 1900 A), dense-core vesicles are present in the nerve terminals. The inhibitory action is mimicked by infusioninto the leg of a minute (0.01 ml.) drop of locust saline containing a very low concentration (10(-6)M) of dopamine or noradrenaline, or an extraordinarily low concentration of octopamine (2.5 x 10(-9) M). The amplitude and frequency of the contractions slowly return to normal. Neither the cell body nor the neuron fluoresces with the Falck-Hillarp treatment, even after a period of ligature has caused an accumulation of vesicles. Octopamine does not fluoresce with this treatment. Accordingly, it is suggested that this neuron, and the other efferent DUM neurons, are octopaminergic.?23Author

Differentiation of the Skaergaard Intrusion

Abstract: Re-examination of the Skaergaard intrusion of East Greenland has revealed that the model of differentiation based on an original liquid with the composition of the chilled margin and a large hidden zone is no longer tenable. The composition of the Skaergaard magma has been determined experimentally for various stages of its evolution, and these compositions are consistent with revised volumetric and compositional data for the individual units of the intrusion. In its later stages, the magma separated into two immiscible liquids, one rich in iron and phosphorus and the other rich in silica and alkalis.

Metastatic Malignant Melanoma in Prepubertal Children

Abstract: Medical literature is full of involved and Confusing reports on the genesis, incidence, and development of metastatic melanoma in children. The reason for this confusion can be found in the early uncertainties that surrounded the real nature and correct diagnosis of metastatic melanoma in the prepubertal child. Before 1950, reports of melanomas with metastases in children were rare, poorly documented, and in many cases erroneous.1-4 In particular, benign nevi (now known as benign juvenile melanoma) went unrecognized and because of their alarming microscopic features were often diagnosed as malignant melanomas. For example, deceived by the predilection of this nevus for childhood, its frightening appearance, and failure to metastasize, Pack and Anglem wrote: ". . . . although malignant melanomas are found in infancy and childhood, they are of low grade malignancy and seldom metastasize" In a later paper, Pack6 coined the term "prepubertal melanoma" for those nonmetastasizing pigmented tumors of children which were microscopically indistinguishable from melanoma. He suggested removal before puberty when endocrinologic stimulation rendered certain of them capable of metastasis. Other investigators also noted this seeming disparity between microscopic appearance and clinical behavior.7 In 1948, Spitz8 provided the criteria for separating this unusual-looking nevus from malignant melanoma and termed it "juvenile melanoma." Later she and Allen9 showed that although these lesions are not restricted to children, they are much more common before puberty.* Subsequent authors10-13 have also classified juvenile melanoma among the benign nevi and the term spindle or epithelioid cell nevus10,12,13 is now preferred. McWhorter and Woolner13 in 1954 reviewed the subject of malignant melanoma in children and suggested that the favorable prognosis was spurious and due to the erroneous classification of spindle and epithelioid cell nevi under the former agnosis.

Melting and premelting phenomenon in DNA by laser Raman scattering.

Abstract: Raman spectra of DNA from calf thymus DNA have been taken over a wide range of temperatures (25°–95°) in both D2O and H2O. A study of the temperature dependence of the Raman spectra shows that the temperature profiles of the intensities and frequencies of the various bands fall into four different categories: (1) base bands that show a reversible increase in intensity prior to the melting region, i.e., a definite premelting phenomenon; (2) base bands that show little or no temperature dependence; (3) deoxyribose-phosphate backbone vibrations that show no temperature dependence up to the melting region, at which point large decreases in intensity occur; and (4) slow frequency changes in certain in-plane vibrations of guanine and adenine due to deuteration of the C-8 hydrogen of these purines in D2O. Certain Raman bands arising from each of the four bases, adenine, thymine, guanine, and cytosine have been found to undergo a gradual increase in intensity prior to the melting region at which point large, abrupt increases in intensity occur. The carbonyl stretching band of thymine, involved in the interbase hydrogen bonding actually undergoes both a gradual shift to a lower frequency as well as an increase in intensity. These changes provide evidence that some change in the geometry of the bases relative to each other begins to occur around 50°C, well below the melting region of 70°–85°C. From the spectra taken at various temperatures, the DNA appears to remain in the B conformation until the melting point is reached, at which time the DNA progresses into a disordered random-coil form. No A-form conformation is found either in the premelting or the melting region.

Morphine and phenytoin binding to plasma proteins in renal and hepatic failure

Abstract: The binding of morphine and phenytoin to plasma proteins was examined in healthy subjects and in patients with renal and hepatic failure In the uremic patients without hepatic failure, morphine binding was dependent on the concentration of total serum proteins and albumin, but not the severity of renal failure as measured by creatinine clearance Binding of phenytoin, however, was dependent on the degree of renal failure and albumin concentration, but not on total serum protein concentration Renal transplant in 1 patient restored the binding of both drugs to a value within the normal range The combination of hypoalbuminemia and hyperbilirubinemia resulted in the greatest impairment to binding for both drugs It is concluded that patients with uremia, jaundice, hypoalbuminemia, particularly in combination, are sensitive to usual clinical doses of morphine, at least in part, because of decreased binding to plasma proteins

A body image scale for evaluating transsexuals.

Abstract: Body image has come to mean not only the way one perceives his body but also how one feels about these perceptions It is an important part of one's total self-concept As such, it can present a significant problem for many individuals For individuals with gender identity problems, such as transsexuals, body image dissatisfaction and distortion are a fundamental aspect of their condition It is possible to more fully understand this condition by appreciating the distinction between the reality of the transsexual's body and his preferred body image The Body Image (BI-I) scale presented here representa an effort to quantify the transsexual's body attitude It consists of 30 body features which the subject is asked to rate on a 5-point scale of satisfaction This test, as part of a larger seven-test battery, was administered to 16 male and 16 female transsexuals The data have been analyzed for comparisons between males and females, for the effects of endocrinological and surgical treatment on body attitude, and for the common denominators which characterize the transsexual's body attitude This instrument is being used as an additional tool in evaluating the transsexual's request for sex-reassignment surgery and in following those individuals who have been accepted for treatment as they progress through the evaluation and treatment program

Choice Behavior in Rats with Hippocampal Lesions

Abstract: Since the early 1960s, an increasingly large number of experiments have been conducted in an attempt to clarify the effects of hippocampal lesions on behavior. Other experimental manipulations, such as chemical and electrical stimulation, spreading depression, and the injection of a variety of drugs into the hippocampus and related brain structures, have added to the existing literature. Some of this literature has been reviewed elsewhere (Isaacson, 1974; Douglas, 1967; Kimble, 1969; Jarrard, 1973; Altman et al., 1973) and it is not my intent to duplicate these efforts. Rather, the purpose of this chapter is to deal principally with a restricted set of these experiments, those dealing with “choice” behavior in rats with bilateral hippocampal lesions. In all experimental situations, even in so-called free exploration, the experimenter places some constraints on the possible behaviors which can be displayed. While it is unrealistic to assume that one is observing true “free” choice behavior in any experimental situation, it is nevertheless possible to obtain rather reliable and consistent data regarding the choice behavior of animals in a variety of experimental situations. This chapter will outline some of the major results which have been obtained so far on the choice behavior of normal, operated control, and hippocampally lesioned laboratory rats.

Synthesis of octopamine by insect dorsal median unpaired neurons

Abstract: Dorsal unpaired median (DUM) neurons of locusts and grasshoppers inhibit the instrinsic rhythm of contraction of metathoracic extensor tibia muscle fibers. This physiological action is mimicked by very low concentrations of octopamine and by higher concentrations of dopamine and noradrenaline. We have examined the synthesis of biogenic amines from tritiated tyrosine by these neurons. DUM cell bodies and a peripheral nerve containing the DUM axon which terminates in the extensor tibia both produced octopamine, but neither noradrenaline nor dopamine synthesis was detected. The observations support the suggestion that the dorsal unpaired median neurons are octopaminergic.