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Immunodominant Antigens of Actinobacillus Actinomycetemcomitans in Antibody Positive SubjectsCalifano, Joseph V. 01 January 1990 (has links)
This study was initiated to look for characteristics of the immunodominant antigen(s) of Actinobacillus actinomycetemcomitans (Aa) that might help explain the high antibody titers reactive with this organism in periodontitis patients. Radioimmunoassays (RIA) and limiting dilution analysis on western blots were used to identify and characterize the immunodominant antigens of Aa in high responder patients (i.e. patients with high antibody titers). Additional experiments focused on specific responding subjects with a range of antibody titers to serotype b (AaY4). This group included both white and black subjects. Similar studies then examined the immunodominant antigens of Aa serotypes a and c. The Aa serotype specificity of the high responders was determined and further work was confined to individuals responding specifically to serotypes a or c. The results indicated that the immunodominant antigen of Aa Y 4 in all high responders was heat and papain stable. Limiting dilution analysis on western blots showed that a large diffuse band resembling carbohydrate was the immunodominant antigen. Partially purified AaY4 carbohydrate also contained the large diffuse band. Double immunodiffusion (Ouchterlony) tests indicated that the dominant antigen recognized in the carbohydrate extract by the patients' sera was the same antigen recognized by serotype b specific rabbit antiserum which has been previously shown to react with the serotype specific carbohydrate of AaY4. When the subjects with specific antibody responses covering a range of positive antibody titers were examined, 95% of the subjects were responding to the smeared serotype specific carbohydrate antigen on western blots. For serotype-a, no immunodominant antigen was common to the majority of high responding subjects. For serotype-c two antigens were immunodominant in the majority of the high responding patients: 92% had an antigen with a diffuse smeared appearance on western blots typical of a carbohydrate antigen and 67% had an approximately 15Kd antigen. The smeared antigen gave a reaction of identity with patient serum and serotype c specific rabbit antiserum in double immunodiffusion assays. These findings indicated that the immunodominant antigen for serotypes-b and-c in high responding subjects was the serotype specific carbohydrate. The same antigen was immunodominant for subjects with a range of antibody titers to AaY4. The dominant antigen was highly variable for serotype-a. These antigens were highly immunogenic. This immunogenicity may explain the enormous antibody titers observed for Aa in response to what appears to be a small quantity of antigen.
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An Analysis of the Fit of the Negative Binomial Distribution to Frequencies of Episodes of IllnessBrennan, Philip Melville, Jr. 01 January 1980 (has links)
In recent years, much interest has been shown in "modeling," or fitting, primary care data to known statistical distributions. Specifically, much work has been done in studying the distributions of episodes of illness and consultations in family practices. This thesis will examine the utility of the negative binomial distribution's fit to family practice data.
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The Two-Way Mixed Model Analysis of VarianceBuckley, Kenneth Davis 01 January 1974 (has links)
The analysis of variance for experiments where the fixed effects or random effects model is appropriate is generally agreed upon with regard to testing procedures and covariance structure. It is only in experiments involving both random and fixed factors, i.e. mixed effects models, that controversy occurs as to the proper analysis. The mixed effect model has been considered by many statisticians, and several techniques have been developed for explaining its structure and performing its analysis for balanced data sets. The relationship of these techniques have been discussed in several papers as well.
The simplest case of the difficulties presented by the mixed effects models occurs in the two-way cross classification model with interaction. The various models for the two-way mixed situation were examined and compared. It was found that Scheffe's model defined the effects in a meaninful way, is completely general, and provides exact tests. In situations where Scheffe's model cannot be applied, it was found that Kempthorne's model or Graybill's model should be used since they define effects in a meaningful way and, under certain assumptions, gives exact tests. Searle's model does not define the effects in the same manner as the former three models. Searle's effects are defined more for mathematical appeal and his model is designed for easy application to unbalanced cases. Consequently, his model was not found to be desirable in balanced two-way mixed effect designs.
In higher order models, Scheffe's modeling techniques were found not to be practical since his test for fixed effect differences in models with more than two random effects cannot be computed. Kempthorne's models and Graybill's models both, under certain assumptions, provide straightforward tests for all effects. For this reason, their modeling techniques are recommended for higher order mixed models involving balanced data sets. Searle's modeling technique was again found unapplicable for balanced data sets in higher order mixed models for the same reasons as those in the two-way case.
The results of the investigation recommends Scheffe's model for two-way situations, but Kempthorne's modeling technique and Graybill's modeling technique seem the most versatile. Although the task would be very cumbersome, further investigation is suggested in comparing Kempthorne's procedure and Graybill's procedure to Scheffe's procedure for testing fixed effect differences.
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Statistical Methods for Detecting and Characterizing Departures from Additivity in Multi-Dimensional Drug/Chemical MixturesDawson, Kathryn S. 01 January 1995 (has links)
In studies of the effects of multiple drug or chemical combinations, one goal may be to detect and characterize the interactions between the agents. The techniques currently applied to this problem have limitations when the experiments involve more than 2 agents. Certain response-surface techniques require an unrealistic number of observations for studies involving a large number of agents. Current graphical methods are impossible to use in studies of 3 or more agents. In this research two statistical techniques are described that can be applied to studies with an unlimited number of agents. In the first approach, dose combinations are collected along rays or at fixed ratios. Using properties of this experimental design, an additive model is derived. Comparing the fitted dose-response curve along each ray to the curve predicted under additivity, synergistic and antagonistic interactions between the agents can be detected. Statistical testing procedures are given to determine if these are significant interactions, not due to random fluctuations in the data. Graphical techniques that enhance the interpretation of the results are described. The second approach developed in this research is a point-wise test which determines if the agents interact in an nonadditive manner. This test can be applied to each dose combination of interest After applying a multiple comparison adjustment to the resulting p-values, departures from additivity can then be characterized. These approaches are likely to be more economical than current techniques, implying that a larger number of agents can be studied in combination for the same experimental effort.
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Expression of Human Neutrophil Elastase in K. Lactis.Klimecki, Haley M. 08 May 2010 (has links)
Human neutrophils are the most abundant type of white blood cell and provide the body with a line of defense against foreign, infectious microorganisms. Contained within the azurophilic granules in the cytoplasm of neutrophils are three serine proteases, Human Neutrophil Elastase, Cathepsin G, and Protease 3. Once a foreign bacterium is engulfed by white blood cells, these enzymes attack and degrade the invading body, thus killing it (Reeves et al., 2002). The focus of this research is centered on the production of one of the serine proteases, human neutrophil elastase (HNE), and while the importance of HNE can be seen, genetic mutations or improper regulation can compromise a person’s immunity. Neutropenia (a low neutrophil count) is one such disease caused by a genetic mutation of HNE that results in susceptibility to infection (Li and Horwitz, 2001). Additionally, HNE is a powerful enzyme that can attack the elastin of the lung if not properly controlled. Consequently, genetic deficiencies of alpha-1 proteinase inhibitor protein in the blood can result in emphysema because active HNE released from neutrophils is free to degrade lung tissue (Laurell and Eriksson, 1965).
Recombinant HNE is not currently available, and the enzyme must be isolated from human blood cells, which has inherent hazards. Additionally, the lack of recombinant HNE has prevented studies involving site–directed mutagenesis to study the intracellular processing of HNE near its C-terminal end where mutations have been found to result in neutropenia. Kinetic studies of the full-length HNE might shed some light on why its C-terminal region is removed before storage in cytoplasmic granules.
The HNE DNA sequence was first codon optimized for yeast and commercially synthesized. It was then fused with DNA for eGFP (enhanced green fluorescent protein) via an enterokinase cleavage site (D4K). This DNA construct (eGFP-D4K-HNE) was then inserted into the Kluyveromyces lactis (K. lactis) pKLAC1 vector, downstream of the alpha mating factor which directs proteins for secretion. Then, chemically competent GG799 cells (a strain of K. lactis) were transformed with the linearized pKLAC1-eGFP-D4K-HNE insert through a protocol from New England Biolabs. Theoretically, the gene integrates into the yeast genome upon transformation via sequences within the pKLAC1 vector that are homologous with the LAC4 gene promoter that allows for galactose utilization (Colussi 2005). Acetamide was used as a selectable marker because wild type K. lactis cells are not able to use acetamide as a nitrogen source. The pKLAC1 vector, however, contains the Aspergillus nidulans gene acetamidase (amdS) that allows only transformants to grow on plates with acetamide as the sole nitrogen source (Read 2007).
Selected colonies were transferred to both liquid and agar-based synthetic media with galactose to induce transcription and translation of the HNE gene to produce the eGFP-D4K-HNE fusion, and screened via fluorescence microscopy for production of eGFP. None of the screened colonies tested positive for the presence of the fusion protein.
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Antioxidants and Wound Healing.Underdown, Mary Jane 11 May 2013 (has links)
Neutrophils and cytokines present during an inflammatory response produce oxidants, such as reactive oxygen species (ROS) or reactive nitrogen species (RNS). These oxidants act as free radicals, a highly reactive species that steal electrons from nearby molecules to satisfy their valence electron needs. The removal of electrons by free radicals produces damage within the healthy cells of tissue. Antioxidants can be used to reduce this oxidative stress and reestablish the necessary environment for wound healing by donating electrons to the free radicals, sparing the damaging effects oxidation causes to other molecules. The standard procedure for administering supplemental antioxidants is through enteral delivery. However, the inflammation and vascular damage experienced with a burn wound produces a notable decrease in the blood profusion to the damaged tissues. In contrast, this research focuses on a topical antioxidant treatment applied directly to the surface of the wound. By applying the gel topically, a higher concentration of antioxidants will be able to permeate the damaged tissue and quench enough free radicals to provide a therapeutic effect. Additionally, the gel developed by this research is comprised of a large percentage of Vitamin E-TPGS. This is a product capable of stabilizing moisture at the wound site; drawing fluid from the moist center and redistributing it to the drier perimeters of the wound. It is hypothesized the need for surgical debridement may decrease as a result of use of this topical application. Antioxidants often referred to in literature discussing nutrition and wound care include the following: Vitamin E, α-Lipoic Acid, Vitamin C, Grape Seed Extract, Coenzyme Q10, Glutathione, and Lutein. These antioxidants were incorporated into a gel formula, using a factorial method, based on their antioxidant potential as evidenced by the existing literature. In order to identify the most effective combination of these antioxidants, one-, two-, three-, four-, and five-component antioxidant gels representing every combination of the test antioxidants were produced. This resulted in a compilation of 35 gels for comparison. Each gel was tested on the basis of viscosity, pH, and antioxidant capacity. Antioxidant capacity was determined using the Ferric Reducing Antioxidant Plasma (FRAP) Assay, a spectrophotometric evaluation. A three-antioxidant gel composed of α-Lipoic Acid, Coenzyme Q10, and Mixed Tocopherols (with and without micronized silver) was chosen as the final formulation. The storage stability of the final formulation was then evaluated once per week (over a total of 7 weeks) by measuring changes in pH, viscosity, and FRAP assay. In collaboration with Dr. Joseph Molnar at Wake Forest School of Medicine, an animal model trial will be conducted in the Spring Semester 2013 to determine the viability of the gel in comparison to a negative control and silver sulfadiazine, the current standard treatment protocol.
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Combining Field Fertilizer Trials with Soil Tests in an Effort to Obtain the Most Suitable Soil Nitrogen and Phosphorous Tests for Southern AlbertaHaniuk, Einard 01 May 1957 (has links)
Under dryland farming operations, the use of fertilizers is often restricted due to limited crop response arising from limited seasonal moisture. Once this dryland area is brought under irrigation, there is increased use of fertilizers and increased demands for greater exactness in amounts of fertilizers to apply, due to efforts which are made to increase the returns from the land by introduction of new farming techniques and crops.
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Neutral 17-Ketosteroid and 17, 21-Dihydroxy-20-Ketosteroid Excretion in Urine of University Women During the Menstrual CycleYam, Shao Shen 01 May 1966 (has links)
In the last few years, much research has been done on lipid metabolism because of the possible involvement of lipids in atherosclerosis and coronary heart disease. These diseases appear to be related to abnormalities in lipid metabolism. Since sex differences have been noted in lipid metabolism, the role of steroid hormones has been under investigation in a number of laboratories. Coronary heart disease occurs only rarely in women during the reproductive phase. In men, the administration of estrogens results in a decreased serum cholesterol level while androgens tend to increase circulating cholesterol.
Experiments on rats and chickens have indicated that both corticosteroids and sex hormones are involved in the regulation of lipid and cholesterol metabolism. In chickens, estrogens decreased the circulating cholesterol and prevented the coronary atherosclerosis that can be induced by feeding cholesterol. The effect of estrogens and androgens on the metabolism of essential fatty acids in rats is under investigation by Ostwald et al. (1965). Female or estrogen-treated rats maintained more arachidonic acid in their plasma phospholipids and cholesteryl esters than did their male counterparts even during acute and prolonged deficiencies of dietary linoleic acid.
Adrenal cortex contains a number of potent hormones all of which are steroid derivatives having characteristic cyclopentanoperhydrophenanthrene nucleus. The corticosteroids are produced by the adrenal gland in both male and female. One measure of corticosteroids activity is the determination of urinary 17, 21-dihydroxy-20-ketosteroids.
The androgens in female are produced by the adrenal cortex and in small amounts by the ovary; in the male by the testis and to a lesser extent in the adrenal cortex. Measurement of the urinary neutral 17-ketosteroids is becoming more frequently used as an index of androgenic activity but it should be borne in mind that the androgenic ptency of a given urine extract will not necessarily parallel 17-ketosteroid concentration.
Until more is known about androgen and 17,21-dihydroxy-20-ketosteroids (DKS), male adrenals, as well as possible androgen secretion by the ovary, the significance of normal neutral 17-ketosteroids and 17,21-dihydroxy-20-ketosteroids determinations in urine are of considerable importance when measured regularly for long periods of time. The measurement of the output of these steroids during several menstrual periods would provide a biochemical index of androgen and corticosteroids secretion in women.
Few, detailed studies of changes in urinary excretion of androgen and corticosteroid end products during the menstrual cycle in normal young women have been reported in the literature. Yu (1964) found that neutral 17-ketosteroids gradually increased from the 9 to 15 days. This increase was significant. However, she did not have values for the rest of menstrual period on her five subjects. Her results indicated that a more detailed study of changes occurring during the menstrual cycle was desirable. Then, if these changes were related to concentrations of the serum fatty acids during the menstrual cycle, basic information on relationships between steroid hormones and lipid metabolism might be obtained. The findings should be important because abnormal metabolism of lipids seems to be one factor involved in several of the degenerative diseases of old age such as atherosclerosis and cerebral hemorrhage.
This study is a part of a larger problem to determine relationships that exist among serum cholesterol, serum fatty acids, and concentrations of estrogens and degradations products of the androgens and corticosteroids in urine in normal young women. The purpose of this study is to determine the changes in concentrations of neutral 17-ketosteroid and 17,21-dihydoxy-20-ketosteroid hormones in women's urine during specified days of the menstrual period, which would help to define the effect of ovulation on the urinary excretion of these hormones.
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The Effect of Bicarbonate on the Uptake of Zinc by PlantsMorrill, Lawrence G. 01 May 1956 (has links)
Zinc deficiencies occur in many fruit orchards in Utah even though the soil contains amounts of zinc that would normally be sufficient for good plant growth. The existing zinc problem in Utah is, therefore, one of availability.
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The Influence of Temperature Gradients on Soil Moisture FlowGavazza, Luigi 01 May 1953 (has links)
The isothermal movement of liquid water in saturated soil has been intensively studied, and a sound theoretical basis has been intensively studied, and a sound theoretical basis has been developed. Considerably less is known about the flow of water in unsaturated soils, but a general theory based on Darcy’s law of flow is beginning to develop. A good theoretical basis exists for the vapor diffusion under isothermal conditions. Inconsistent data and theories are found in the literature concerning the movement of water in both the vapor and liquid phases, under the influence of thermal fields.
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