Absence of Interferon-γ–Inducible Gene IGTP Does Not Significantly Alter the Development of Chagasic Cardiomyopathy in Mice Infected with Trypanosoma cruzi (Brazil Strain)

Interferon-γ (IFN-γ) contributes to host resistance during acute infection with Trypanosoma cruzi, the causative agent of Chagas’ disease. Inducibly expressed guanosine triphosphatase (IGTP), a 48-kDa guanosine triphosphatase (GTPase), is a member of a family of GTPase proteins inducibly expressed by IFN-γ. The expression pattern of IGTP suggests that it may mediate IFN-γ–induced responses in a variety of cell types. IGTP has been demonstrated to be important for control of Toxoplasma gondii infection but not for resistance against Listeria monocytogenes. We evaluated the role of IGTP in development of chronic chagasic cardiomyopathy in IGTP null mice and C57X129sv (wild type [WT]) mice infected with the Brazil strain for 6 mo. There was no significant difference in parasitemia or cardiac histopathology between null and WT mice. Right ventricular remodeling was observed in infected IGTP null mice, suggesting that IGTP does not significantly alter the course of T. cruzi infection.

The Use of Factor Analysis in the Development of Hand Sizes for Glove Design

Factor analysis was used to develop a more detailed description of the human hand to be used in the creation of glove sizes; currently gloves sizes are small, medium, and large. The created glove sizes provide glove designers with the ability to create a glove design that can provide fit to the majority of hand variations in both the male and female populations. The research used the American National Survey (ANSUR) data that was collected in 1988. This data contains eighty-six length, width, height, and circumference measurements of the human hand for one thousand male subjects and thirteen hundred female subjects. Eliminating redundant measurements reduced the data to forty-six essential measurements. Factor analysis grouped the variables to form three factors. The factors were used to generate hand sizes by using percentiles along each factor axis. Two different sizing systems were created. The first system contains 125 sizes for male and female. The second system contains 7 sizes for males and 14 sizes for females. The sizing systems were compared to another hand sizing system that was created using the ANSUR database indicating that the systems created using factor analysis provide better fit.

On the Ecology and Distribution of Echinococcus spp. (Cestoda: Taeniidae), and Characteristics of Their Development in the Intermediate Host. II. Comparative Studies on the Development of Larval E. multilocularis Leuckart, 1863, in the Intermediate Host

This paper reports the results of a comparative study of the development of the larval Echinococcus multilocularis Leuckart, 1863), and associated tissue reaction in naturally and experimentally infected mammals representing 31 species. The histogenesis of the larval cestode was traced in detail in arvicoline rodents of several species, and interspecific differences were defined. In arvicoline rodents, the developing larva exhibited host-specific characteristics within about a month after infection was established. The tissue reaction in Microtus oeconomus was characterized by the production of a large quantity of detritus around the larva, and by the formation of a thick epithelioid zone. In one subspecies, M. oeconomus innuitus, development of the larva was retarded, and the detrital mass was often calcified; in another, M. oeconomus operarius, the detritus rarely became calcified and the larva proliferated more rapidly. In M. pennsylvanicus, the tissue reaction was minimal, and little detritus was present. The characteristics of the tissue reaction in M. montebelli placed it in an intermediate position between the aforementioned species. In Clethrionomys rutilus, a thin epithelioid zone and an outer zone of loose collagenous fibers composed the adventitial layer; exogenous budding was retarded in this vole. A minimal tissue reaction occurred in Lagurus curtatus. In Lemmus spp., larger cysts were characteristic, but areas of small-cystic proliferation were always present. Similar differences in species or subspecies of Citellus and Dicrostonyx were described. Lesions of alveolar bydatid disease in man also were studied. The invasive growth of the larval cestode in the human liver involves a process comparable to small-cystic proliferation in the natural intermediate hosts. Although the later stages of development of the larval cestode are inhibited in man, exogenous proliferation of vesicles continues for the life of the host. The lesion in man was compared with a morphologically similar formation produced by anomalous development of the larval E. granulosus in the bovine liver. The latter is distinguished by the absence of areas of small-cystic proliferation. Non-echinococcal lesions found in the tissues studied, some of which resembled foci caused by the larval E. multilocularis, were briefly discussed.

MATERIAL MODELING AND ANALYSIS FOR THE DEVELOPMENT OF A REALISTIC BLAST HEADFORM

Blast traumatic brain injury (BTBI) has become an important topic of study because of the increase of such incidents, especially due to the recent growth of improvised explosive devices (IEDs). This thesis discusses a project in which laboratory testing of BTBI was made possible by performing blast loading on experimental models simulating the human head. Three versions of experimental models were prepared – one having a simple geometry and the other two having geometry similar to a human head. For developing the head models, three important parts of the head were considered for material modeling and analysis – the skin, skull and brain. The materials simulating skin, skull and brain went through many testing procedures including dynamic mechanical analysis (DMA). For finding a suitable brain simulant, several materials were tested under low and high frequencies. Step response analysis, rheometry and DMA tests were performed on materials such as water based gels, oil based mixtures and silicone gels cured at different temperatures. The gelatins and silicone gels showed promising results toward their use as brain surrogate materials. Temperature degradation tests were performed on gelatins, indicating the fast degradation of gelatins at room temperature. Silicone gels were much more stable compared to the water based gels. Silicone gels were further processed using a thinner-type additive gel to bring the dynamic modulus values closer to those of human brain matter. The obtained values from DMA were compared to the values for human brain as found in literature. Then a silicone rubber brain mold was prepared to give the brain model accurate geometry. All the components were put together to make the entire head model. A steel mount was prepared to attach the head for testing at the end of the shock tube. Instrumentation was implemented in the head model to obtain effective results for understanding more about the possible mechanisms of BTBI. The final head model was named the Realistic Explosive Dummy Head or the “RED Head.” The RED Head offered potential for realistic experimental testing in blast loading conditions by virtue of its material properties and geometrical accuracy.