Although pertussis vaccines have been available for over 7 decades, countries are experiencing a pertussis resurgence. This study sought to establish a relationship between the European pertussis immunization schedule designs (with and without the inclusion of adolescent boosters) and the immunization requirement (recommended or required), which potentially influences immunity waning, and thus the incidence rate and epidemiologic cycles of pertussis. The theoretical foundation for this study was the theory of herd immunity. A quantitative research method was used, supported by a secondary data source. The statistical analysis included the use of linear regression to evaluate the relationship between the requirement of the vaccine and the addition of adolescent boosters on the incidence level and the length of the epidemiologic cycles. The study findings suggest that pertussis immunization, whether recommended or required, does have an influence on the incidence rate within the populations of the countries analyzed. The same influence on incidence was demonstrated in relation to adolescent boosters as part of the immunization schedule. A similar relationship was not observed between the immunization schedule requirement and design on the epidemiologic cycles. This study provided relevant data that contributes to the enhanced understanding of the relationship between the design of the immunization schedule on incidence. This understanding could help control the resurgence, reduce immune waning through adolescent boosters, enhance immunization schedule timing, and lower the incidence. The result would be a positive public health social change through improved immunization strategy.

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The purpose of this study was to investigate the hiring practices of physicians’ offices as they relate to medical assistants and to gain insight into their hiring preferences. Knowing how physicians and medical office managers view the profession of medical assisting may help medical assisting professionals improve the standing of the profession and provide a consistent foundation for education programs. I surveyed 15 physicians’ practices in eight states across the country to obtain a cross-country perspective and found that many practices hire credentialed or non-credentialed individuals for clinical positions for various reasons. The reasons were minimally due to the lack of credentialed applicants and more due to personal preferences, financial decisions, and governmental regulations. This study contributes to medical assisting program directors, medical assisting professional organizations, and credentialing agencies in promoting medical assisting.

Transfection is the process of introducing DNA into cells and expression of the gene contained in the DNA. The DNA itself could be a functional gene, part of a gene, or a gene with the regulatory and transcribed sequences intact. The ability to transfect mammalian cells is a powerful tool that can be used to study the function and control of mammalian genes. Transfection of DNA into eukaryotic cells can be done in several ways. One of the methods of introducing foreign DNA into mammalian cells is known as cationic liposome-mediated transfection. Preliminary studies involved the development of a cationic lipid-mediated transfection method using HeLa cells and a plasmid that codes for ~-galactosidase. The cationic lipid used was Transfectam. Transfectam is a commercially available, cationic lipopolyamine. Chitosan, a cationic polymer of glucosamine, was used as an alternative transfecting agent and as a binding agent for polyanions. The transfection efficiency of chitosan was compared to that of Transfectam. Chitosan was found to be comparable to Transfectam in this regard. Polyanions of different chemical structures were used in a chitosan binding study. These include aurin tricarboxylic acid, calf thymus DNA and methyl green DNA. The kinetics of the binding interactions suggest that ionic interactions predominated. Based upon these findings, studies were performed to determine the nature of chitosan interactions with the cell surface. Chitosan beads were prepared to determine the interaction of chitosan with the cell membrane of He La cells and for the isolation of membrane proteins. Membrane proteins which bound to chitosan beads could be effectively eluted with a-0-mannopyranoside but not sodium chloride. Furthermore, HeLa cells bound to the chitosan beads could be eluted with aD- mannopyranoside but not sodium chloride. The results suggested that membrane bound proteins interact with chitosan through carbohydrate moiety interactions which may facilitate the transfection process.

In the present study, the effects of selected concentrations (0, 0.375, 0.75, 1.5 and 2.25% w/w) of ethyl oleate or oleic anhydride, the latentiated forms of catalyst oleic acid, were compared with regard to the release characteristics of metronidazole (1 0% w/w) from poly( ortho esters) films in distilled water at 3 7 °C. The rate of release of metronidazole from poly(miho esters) films was dependent on the ethyl oleate or oleic anhydride concentrations. The poly(ortho esters) films with adjuvants demonstrated slower drug release for all concentrations of ethyl oleate studied and for 0.375% and 0.75% w/w of oleic anhydride. The effects of drug loading (5, 7.5 and 10% w/w) and film thickness (150 to 400 !J.m) were also studied in the presence of 0.75 %w/w of either adjuvant. Increasing drug loading enhanced the rate of drug release from films of same thickness. However, variation of film thickness (150 to 400 !J.m) did not significantly alter the release profile possibly due to high concentration of the drug in the film (10% w/w). Gel permeation chromatography, scanning electron microscopy and near zero-order release, in vitro, suggested that the steady-state release of metronidazole from the poly( ortho esters) films following the burst effect occurred initially by a combination of diffusion and surface erosion of the polymer. Later, the release was further complicated by onset of bulk erosion of the polymer due to catalysis by oleic acid produced by ester or anhydride hydrolysis.

This thesis constitutes a report on a series of studies undertaken on possible mechanisms of action of the bioflavonoid, hesperidin methyl chalcone (HMC), in causing smooth muscle to relax. The term bioflavonoid refers to several compounds that can be extracted from the mesocarp of citrus fruits. They have been the subject of investigation and controversy since 1936. Much of this is covered in a eview by Vogin (1). As mentioned in the review, Szenti-Gyorgyi observed first that crude citrus extracts were more efficient in relieving experimental scurvy than pure extract containing only Vitamin C. The subject of scurvy has been covered in many reviews, and no purpose would be served in describing all these factors at this time. However, since Szent-Gyorgi’s observation, there has been considerable study of the possibility that bioflavonoids are a factor in capillary integrity. Despite all the activity, the necessity of bioflavonoids as a dietary adjuvant has not been established. At this date, almost thirty years after the initial studies, the literature is replete with contradictory statements on almost every phase of bioflavonoid activity. The possibility that HMC might have a direct action on smooth muscle indicated that both in vivo and in vitro studies should be utilized. The in vivo studies consisted of observations on blood pressure and nictitating membranes of cats. The in vitro studies were performed on sections of rabbit ileum.

Continuing the study of the relationships between fibrin investment of the tumor, vascularity, and tumor growth, we decided to investigate the relationship of warfarin sodium anticoagulation with tumor growth and vascularization. It was reasoned that if the previously observed altered tumor growth was due the heparin’s anticoagulant effect rather than a direct effect upon the tumor, another anticoagulant with a different mechanism of action would have the same tumor growth reducing capabilities. Warfarin sodium produces reduced fibrin polymer formation by a mechanism entirely different from that of heparin. Heparins’ immediate anticoagulant activity results from a blockade of thrombin’s activity results from a blockade of thrombin’s activity on fibrinogen, prevention of prothrombin conversion to thrombin, and a reduction in platelet adhesiveness. Warfarin’s delayed activity, however, is through an inhibition of vitamin K activity leading to reduced synthesis of several clotting factors. With the decision to use warfarin sodium, experiments were designed to test the hypothesis that a reduction of prevention of fibrin formation and thus tumor encasement with this polymer would alter tumor growth. It was also hypothesized that, accompanying the altered tumor growth, several macroscopic factors including tumor vascularization, extent of tumor attachment, vasodilation of host blood vessels in the locale of the implanted tumor, and local edema fluid would be altered. Experiments were conducted to determine the relationship between the dose of warfarin sodium administered and the degree of alteration of tumor growth and the related factors. An inverse dose-response relationship between dose of warfarin and tumor growth and the related parameters was hypothesized.

Inflammation appears to be an attempt by the organism to re-establish homeostasis as a response to local reactive change in tissues following injury or irritation. This injury or irritation (whether caused by micro-organisms, toxins, antigens, etc.) first leads to an increased passage of fluid through the walls of the microvasculature, followed by stasis of circulation within the affected area. This, in turn, is followed by migration of leukocytes into the area and finally concluded by connective tissue proliferation leading to the deposition of granulation tissue. There are many experimental models employed for the evaluation of drugs with possible anti-inflammatory activity. Since many of these systems employ whole animals, it seems rational that various hematological parameters could be applied. Our purpose was to test such parameters in two selected systems (i.e., adjuvant-induced arthritis and cotton pellet granuloma formation) during drug evaluation. The parameters under investigation included: total white blood cell count, differential leukocyte count, sedimentation rate and serum protein patterns.

A number of studies have investigated the natural history of asthma in pregnancy. Most of the data suggests that the course of asthma for a given patient is unpredictable. Turner, et al.7 summarize the data from all of the English-language literature of studies on the effect of pregnancy on astha. Of 1054 cases examined, 49% of the asthma conditions remained unchanged, 22% got worst and 29% became better.7 Theophylline has been used safely during pregnancy. A review of the literature by O'Brien, showed that no teratogenic effects were associated with the use of theophylline in 117 cases and aminophylline in 76 cases examined.39,40 Blood concentration in newborns have been found to be similar to concentrations in the mothers.41,42,43 Problems developed because theophylline clearance may be altered during pregnancy and necessitate dosage adjustments and careful drug level monitoring.44 RATIONALE FOR STUDY Campbell, et al.45 developed a caffeine urinary metabolic ratio, in which they were able to demonstrate a correlation between changes in metabolic rations and clearance. The change in the metabolic ration explained the alteration in clearance and determined the specific Cytochrome P-450 system involved. Various physiologic changes occurring during pregnancy can cause changes in drug disposition. Pharmacokinetic parameters that need to be considered are plasma protein binding capacity, absorption, drug metabolizing enzyme activity, renal excretory function and volume of distribution.44,46,47 This study was developed to determine if changes in theophylline disposition during pregnancy were due to changes in drug metabolizing enzyme activity. A urinary test was designed to investigate the ratios of unchanged theophylline and theophylline metabolites to monitor changes in the various Cytochrome P-450 isoenzyme systems. Changes in the ratios could provide a noninvasive procedure to assess the effect of modulating agents or conditions (such as pregnancy) on theophylline metabolizing enzyme activity.