<p>The pilidium larva is an idiosyncrasy defining the Pilidiophora. Its development is unique, and conserved even in derived pilidia; the juvenile is formed via a series of invaginations of the larval epidermis (imaginal discs), then bursts through the larval body while simultaneously consuming it in catastrophic metamorphosis. Pilidium nielseni is a lecithotrophic pilidium with two circumferential ciliary bands reminiscent of the ?prototroch? and ?telotroch? of a trochophore larva, the ancestral larval form of spiralians. However, pilidium nielseni represents a convergence on this larval form, not the resurgence of the ancestral larva, and typical pilidial development is conserved. In this thesis, I describe the development of pilidium nielseni, and determine it has converged on its body plan at least twice, independently.

Natural killer (NK) cells were first described 16 years ago. Studies with athymic or neonatally thymectomized mice showed they had relatively low incidences of carcinogen-induced tumors and good resistance during the initial encounter with viral infection. These mice lacked mature T cells, but had normal or elevated numbers of cells able to lyse certain tumor cell lines without prior stimulation. Subsequent studies have shown that NK activity can be enhanced by cytokines, specifically by interferons (IFN) and interleukin-2 (IL_2). A second type of unrestricted tumor cell killing has been described. Lymphocytes, incubated overnight with IL-2, acquire the ability to kill both fresh tumor cells and tumor cell lines resistant to killing by NK cells. These cells are known as lymphokine-activated (LAK) cells. This thesis will discuss the properties of LAK and NK cells, their unclear relationship with each other, and the regulatory effects of IFN and IL-2 on their activity.

By means of electron microscopy, a study has been made of the fine structure of the second-generation merozoites of Eimeria tenella obtained in scrapings of epithelial cells from the caecum of white leghorn cockerels. These specimens were fixed in osmium tetroxide and osmium permanganate, embedded in Epon 812, sectioned with a diamond knife, mounted on uncoated 300-mesh grids and examined in a Philips EM lOO-C microscope. This study revealed numerous points of similarity to Toxoplasma, Sarcocystis, Plasmodium, Lankesterella, Eimeria intestinalis and Eimeria bovis. The merozoite was fusiform-shaped and enclosed in a cell membrane. Some structural views revealed a discontinuity of the membrane made by a micropyle in the vicinity of the nucleus. Golgi apparatus lay near the nucleus. The polar ring anterior was situated in a cone-like body called the apical cone.. Paired organelles and convoluted tubules were also visible. Numerous mitochondria were scattered in many views of the parasite. Dense and semi-dense membrane enclosed bodies, possibly protein, were occasionally found near the mitochondria. Cross section of the mitochondria revealed tubular cristae situated in a dense matrix. Numerous free ribosomes and ribosomes attached to rough-surfaced endoplasmic reticulum surrounded these sections.

The embryological and larval development of Pachymedusa dacnicolor was investigated. P. dacnicolor belongs to the Phyllomedusinae (Leaf Frog) Subfamily of the Hylidae (Treefrog) Family. No complete developmental table for any member of the Hylidae exists. Therefore, this developmental table was produced for P. dacnicolor including stages from egg to the end of metamorphosis. The rate of development at different temperatures was included in the study. Investigation revealed that the development of P. dacnicolor is similar to that of other anurans, but several differences were noted. Many of these differences relate to the fact that oviposition occurs in foliage out of water. Developmental peculiarities include: (1) lack of an externally obvious grey cresent; (2) dorsal lip is located more dorsally than is usual; (3) appearance of what resembles a blister at earliest gastrulation (probably the thin roof of the blastocoel) along with an equatorial canal that briefly appears at stage 10.1 (beginning of gastrulation); (4) well developed subblastopore papilla, which develops into the anus; (5) fusion of the operculum begins in the midline and moves lateraly in both directions, but leaves a spiracle just lateral to the ventral midline on the left side; (6) the hind limb bud is short and thick; (7) in hind limb formation the second indentation appears before the first; (8) subarticular tubercles appear before the metatarsal tubercle develops. The most externally obvious difference between P. dacnicolor and other Anurans is the advanced state of development at hatching. Hatchlings are completely formed tadpoles, viz., they possess fully formed eyes, mouth, tail with fins, etc. P. dacnicolor has no oral sucker. The gills of P. dacnicolor larvae are unusually long, and are probably indicative of the environmental constraints placed upon this frog: it is hypothesized that P. dacnicolor may exist close to the minimum physiological tolerance for O₂ due to the high temperatures to which the egg masses are subjected. Temperature studies show best development is obtained at 30°C, which correlates well with temperatures reported in the field.

<p> Tumor metabolism is a highly dysregulated process that is identified as a unique target for therapy. Current philosophy proposes that tumor metabolism is a plastic and flexible process which sustains proliferative and survival advantages. Tumors employ an anaerobic glycolytic pathway resulting in the overproduction of lactate. Additional thinking suggests that the conversion of pyruvate to lactate regenerates the NAD+ pool in the cell, maintaining a sustainable oxidative environment. Regardless of the reasons for lactate overproduction, its excretion and build up in the microenvironment results in acidic tumor microenvironments. Tumor acidosis has been measured with several different methods, but consistently averages from pH 6.6 to 7.0. Tumor acidity can thus be measured as a biomarker for tumor metabolism. This work examines the commonly explored energy pathways available to the cancer cell and a non-invasive MRI method to measure the efficacy of the tumor metabolism targeting agent. Appendix A is an introduction to tumor metabolism pathways and the large list of candidate therapies in interfering with energy production. Glucose, fatty acid, and glutamine metabolisms are all discussed along with PI3K/AKT/mTOR and HIF growth signals and ion transport. Magnetic resonance imaging and positron emission tomography are examined as imaging methods for non-invasively interrogating tumor acidosis. Appendix B presents the findings in a study where tumor metabolism was targeted with an mTOR inhibitor, where tumor growth rate was initially decreased and accompanied by an early, acute increase in tumor extracellular pH with acidoCEST MRI. Chapter 2 discusses the combination of a lactate dehydrogenase inhibitor in conjunction with doxorubicin in a breast cancer model. Tumor extracellular pH was shown to increase when measured with acidoCEST MRI, and an increase in cell death was measured. Chapter 4 discusses the studies and experimental designs that can be done in the near future.</p>

No description available.

No description available.

No description available.

<p> INTRODUCTION: Implant placement in the posterior maxilla can be challenging due to the pneumatization of the maxillary sinus and inadequate vertical bone height. The aim of this study was to compare the volumetric change in maxillary sinuses associated with extractions and ridge preservation versus those that have undergone extraction only.</p><p> METHODS: This retrospective study utilized cone beam computed tomography (CBCT) from archived dental records of patients who had extractions of posterior maxillary teeth. Only patients with both pre- and post- extraction CBCT were included. Data included the date the radiographs were taken, date of extraction or extraction with graft placement, and tooth extracted. Pre- and Post- extraction DICOM files were opened in InVivo v5.3 software (Anatomage) for image manipulation. After the volumes of the sinuses were isolated utilizing a series of volumetric rendering views and trimming instruments in InVivo v5.3, the volume calculation tool was utilized to assess the size of the sinuses. Means, standard error of the mean (SEM), and unpaired t tests between the grafted and non-grafted sites were compared.</p><p> RESULTS: 39 patients with 55 sinuses were available for review. A total of 36 extraction sites with ridge preservation and 26 without ridge preservation were included in the final data set. Sinuses associated with extraction sites receiving graft material showed a mean increase of 0.16 &plusmn; 0.15cc, whereas sinuses associated with non-grafted extraction sites showed a mean sinus increase of 0.66 &plusmn;0.61cc (mean difference of 0.50 cc). The mean change in sinus volume associated with extracted single first or second premolars with ridge preservation was 0.03cc whereas the mean change in sinus volume associated with single non-grafted premolar extractions sites was 0.36cc (difference of 0.33cc). The difference between the groups was 0.33cc. The mean change in sinus volume associated with single extracted molars that received ridge preservation was 0.15cc whereas the mean change in sinus volume associated with single extracted molar sites without ridge preservation was 0.95cc (mean difference of 0.80cc). In split mouth cases, the mean change in grafted sites was 0.29cc compared to 1.21cc (mean difference 0.92cc). Tooth position in the arch was directly related to the amount of post-extraction sinus pneumatization. </p><p> CONCLUSIONS: Mean volumetric change of the maxillary sinus is significantly greater in non-grafted maxillary posterior tooth extraction sites. Maxillary sinus volume and topography may be maintained by the grafting of maxillary posterior tooth extraction sites. Ridge preservation may be advantageous in preserving the vertical alveolar ridge dimension both intraorally and intra-antrally. </p>

Two groups of male New Zealand white rabbits weighing 2.5-3.9 kg were maintained on high and low sodium diets for a period of 3 weeks. Urine samples were collected daily during the 3-week period from each rabbit and analyzed for sodium and potassium concentrations. A control group of rabbits was also maintained over a 3-week period, with daily urine collections. Each rabbit was anesthesized with sodium pentobarbital (35 mg/kg) via the marginal ear vein. Following the loss of consciousness, the right external jugular vein was cannulated in order to induce volume expansion and depletion. The left common carotid artery was also cannulated in order to monitor arterial blood pressure during the volume expanded and depleted procedures. Urine from rabbits on the high sodium diet contained high concentrations of potassium and sodium, whereas urine from rabbits on the low sodium diet had very low sodium and potassium levels as compared to control group readings. An elevated arterial blood pressure was observed in the high sodium rabbits and the low sodium rabbits had arterial blood pressures below control levels. Renin levels were slightly elevated during volume expansion in the high sodium rabbits but was significantly decreased in the low sodium and control groups. During volume depletion, renin levels were observed to decrease in the high sodium rabbits but increased significantly in the low sodium and control rabbits respectively.