Parasitology Commons^™

Giardia Lamblia: Genomic And Molecular Analyses Of Flippase, Diana Leticia Villazana-Kretzer

Open Access Theses & Dissertations

Giardia lamblia, is an intestinal protozoan parasite responsible as a major cause of water-borne intestinal infection in humans (giardiasis). It has been proposed earlier that Giardia has limited lipid synThesis ability and therefore relies on preformed lipid molecules from outside sources. It has also been proposed that lipids are taken up through passive and active transport, and giardial flippasse play a significant role in this process. This study describes the identification and characterization of a putative homologue of flippase gene from Giardia. Flippase is an enzyme that functions as a trans-bilayer transport system facilitating the flip flop diffusion of phospholipids …

Design, Synthesis, And Evaluation Of 10-N-Substituted Acridones As Novel Chemosensitizers In Plasmodium Falciparum, Jane X. Kelly, Martin J. Smilkstein, Roland A. Cooper, Kristin D. Lane, Robert A. Johnson, Aaron Janowsky, Rozalia A. Dodean, Rolf Winter, Michael Riscoe

Collected Faculty Scholarship

A series of novel 10-N-substituted acridones, bearing alkyl side chains with tertiary amine groups at the terminal position, were designed, synthesized, and evaluated for the ability to enhance the potency of quinoline drugs against multidrug-resistant (MDR) Plasmodium falciparum malaria parasites. A number of acridone derivatives, with side chains bridged three or more carbon atoms apart between the ring nitrogen and terminal nitrogen, demonstrated chloroquine (CQ)-chemosensitizing activity against the MDR strain of P. falciparum (Dd2). Isobologram analysis revealed that selected candidates demonstrated significant synergy with CQ in the CQ-resistant (CQR) parasite Dd2 but only additive (or indifferent) interaction in the CQ-sensitive …

The Plasmodium Falciparum Chloroquine Resistance Transporter, Pfcrt, Mediates The Activity Of Chloroquine-Resistance Reversal Agents In The Malaria Parasite, Kristin Lane

Biological Sciences Theses & Dissertations

Chloroquine (CQ) resistant Plasmodium falciparum is a serious problem affecting 3.2 billion people in over 100 countries today. Most endemic malarious countries are among the poorest in the world and lack the resources to replace the inexpensive and highly effective CQ. CQ resistance (CQR) reversal agents are a potentially inexpensive solution to restoring CQ efficacy. CQR reversal agents are drugs that have little to no antimalarial activity alone, but in combination with CQ, they increase dmg accumulation in the parasite and enhance the sensitivity to CQ in CQR parasites. PfCRT is a putative transporter located on the parasite digestive vacuole …

Bird Movement Predicts Buggy Creek Virus Infection In Insect Vectors, Charles R. Brown, Mary Bomberger Brown, Amy T. Moore, Nicholas Komar

School of Natural Resources: Faculty Publications

Predicting the spatial foci of zoonotic diseases is a major challenge for epidemiologists and disease ecologists. Migratory birds are often thought to be responsible for introducing some aviozoonotic pathogens such as West Nile and avian influenza viruses to a local area, but most information on how bird movement correlates with virus prevalence is anecdotal or indirect. We report that the prevalence of Buggy Creek virus (BCRV) infection in cimicid swallow bugs (Oeciacus vicarius), the principal invertebrate vector for this virus, was directly associated with the likelihood of movement by cliff swallows (Petrochelidon pyrrhonota), an amplifying host …

Ecological Correlates Of Buggy Creek Virus Infection In Oeciacus Vicarius, Southwestern Nebraska, 2004, Amy T. Moore, Eric A. Edwards, Mary Bomberger Brown, Nicholas Komar, Charles R. Brown

School of Natural Resources: Faculty Publications

Buggy Creek virus (family Togaviridae, genus Alphavirus, BCRV) is an alphavirus within the western equine encephalitis virus complex whose primary vector is the swallow bug, Oeciacus vicarius Horvath (Hemiptera: Cimicidae), an ectoparasite of the colonially nesting cliff swallow, Petrochelidon pyrrhonota, that is also a frequent host for the virus.We investigated ecological correlates of BCRV infection in 100-bug pools at 14 different swallow colony sites in southwestern Nebraska from summer 2004, by using plaque assay on Vero cells to identify cytopathic virus and reverse transcription-polymerase chain reaction to identify noncytopathic viral RNA. We found 26.7% of swallow bug pools …

Design, Synthesis, And Evaluation Of 10-N-Substituted Acridones As Novel Chemosensitizers In Plasmodium Falciparum, Jane X. Kelly, Martin J. Smilkstein, Roland A. Cooper, Kristin D. Lane, Robert A. Johnson, Aaron Janowsky, Rozalia A. Dodean, David J. Hinrichs, Rolf Winter, Michael Riscoe

Biological Sciences Faculty Publications

A series of novel 10-N-substituted acridones, bearing alkyl side chains with tertiary amine groups at the terminal position, were designed, synthesized, and evaluated for the ability to enhance the potency of quinoline drugs against multidrug-resistant (MDR) Plasmodium falciparum malaria parasites. A number of acridone derivatives, with side chains bridged three or more carbon atoms apart between the ring nitrogen and terminal nitrogen, demonstrated chloroquine (CQ)-chemosensitizing activity against the MDR strain of P. falciparum (Dd2). Isobolograrn analysis revealed that selected candidates demonstrated significant synergy with CQ in the CQ-resistant (CQR) parasite Dd2 but only additive (or indifferent) interaction in the CQ-sensitive …

Myxozoan Genera: Definition And Notes On Taxonomy, Life-Cycle Terminology And Pathogenic Species, Jiří Lom, Iva Dyková

Harold W. Manter Laboratory of Parasitology: Library Materials

A list of myxozoan genera is presented in the current taxonomical scheme. These genera are defined; their type species and most important pathogens along with their hosts are listed. Simultaneously, definitions of actinospore stages representing sexual stages of the myxosporean life cycle are given; altogether, 17 actinospore collective groups with 180 types have been described. Life cycles of the two classes of the phylum Myxozoa, Malacosporea and Myxosporea, are briefly outlined with specification of the appropriate terms. Up to now, 4 malacosporean and 2,180 myxosporean species assigned to a total of 62 genera, have been established. The surviving classification of …

Effects Of Corticosteroids And Of Cyclosporin A On Trypanosoma Musculi In Mice And In Culture, Philip Stephen Schuyler

Loma Linda University Electronic Theses, Dissertations & Projects

The in vivo and in vitro effects of cyclosporin A and corticosteroids on Trypanosoma musculi were examined. Mice that received continuous administration of 6 mg/liter/day of dexamethasone in drinking water and 200 mg/kg hydrocortisone acetate as a single dose 24 hrs prior to injection with T. musculi had significantly higher and longer parasitemias, than controls. Body and spleen weights and B cell responsiveness were lower in test animals and there were some deaths. Mice injected with T. musculi that received 100 mg/kg/day cyclosporin A had longer, but not higher, parasitemias than controls. Corticosteroids appear to partially inactive antibody production (i.e. …

Rhizoctonia Patch Of Cereals, G C. Macnish

Journal of the Department of Agriculture, Western Australia, Series 4

Rhizoctonia patch is now widespread within Western Australia, having been recorded on all cereals and on a wide variety of other crops and pasture plants. Although the disease-as its name implies - looks spectacular in the field, the overall reduction in crop yield is probably small. However, its increasing frequency is causing considerable concern as the disease appears to be associated with minimum or reduced tillage systems.

A Rapid Concentration And Identification Technique For Human Malaria Infections Using A Mouse Model, Donald D. Barton

Loma Linda University Electronic Theses, Dissertations & Projects

Red blood cells infected with malaria parasites experience a change in density making them lighter (less dense). This paper reports a new, rapid diagnostic technique using this change in density in the infected red blood cell. It is not only easy to use, but it is also compatible with the technological conditions found where the malaria problem is most acute - in many developing countries of the world. A small sample of blood drawn from a simple finger stick can be concentrated and examined microscopically for malaria parasites within 10 minutes. The thick film slide preparation, presently used, takes a …

Cryptosporidiosis In The Immunosuppressed Mouse And In Cell Culture, Mercy Prabhu Das

Loma Linda University Electronic Theses, Dissertations & Projects

Cryptosporidiosis is a parasitic infection primarily of animals that has been recently recognized as an important disease in immunocompromised humans. Most cases to date have occurred in patients with acquired immunodeficiency syndrome (AIDS). Persons with abnormal humoral or cellular immune function, and even normal subjects, have also been affected.

To determine whether or not mice, when experimentally immunosuppressed, would develop cryptosporidiosis, a test was designed using the AKR/J strain. This strain was selected because, it was previously reported that it was the strain shown to respond most readily to the production of disease caused by the opportunistic protozoan, Pneumocystis carinii …

The Effects Of Temperature And Ph On The Differentiation Of Trypanosoma Lewisi (Kent, 1880) Laveran & Mesnil, 1901, In A Defined Medium, Carolann R. Rosario

Loma Linda University Electronic Theses, Dissertations & Projects

Trypanosoma lewisi is an arthropod-transmitted protozoan parasite found in the bloodstream of rats. In its life cycle it undergoes cellular differentiation. It is primarily found as the trypomastigote form in the rat and as the epimastigote form in the arthropod, the rat flea. Various studies have been done on hemoflagellates to determine the factors responsible for stimulating the differentiation from one form to the other. Included in these factors are pH, temperature, and protein fractions from fetal calf serum. Recent efforts have also been aimed at developing simple or defined media for physiological or biochemical studies on hemoflagellates. The purpose …

Effects Of Trypanosoma Musculi Kendall, 1906 Immune Serum On The Reproduction Of Trichinella Spiralis (Owen, 1835) Railliet, 1896 In Mice, Samuel L. Chafin

Loma Linda University Electronic Theses, Dissertations & Projects

The possible effects of ablastin, a reproduction-inhibiting antibody which is produced during the infection of the blood parasite, Trypanosoma musculi in the mouse, were investigated by fractionating the parasite into a supernatant fraction (designated as Group A test mice) and a pellet fraction (Group B test mice). These groups A and B mice were injected with the respective fractions, plus Freund’s Complete Adjuvant (FCA). Control mice were injected with FCA only. Sera from these three groups of mice were removed after the Group A and Group B mice were shown to be negative to T. musculi challenge, and Group A …

Concurrent Infection Of Trypanosoma Musculi Kendell, 1906, And Schistosoma Mansoni Sambon, 1907 In Mice, Berhane Andeberhan

Loma Linda University Electronic Theses, Dissertations & Projects

The possible effects of ablastin on Schistosoma mansoni were investigated by (1) establishing a concurrent infection of Trypanosoma musculi and Schistosoma mansoni in mice, and (2) by obtaining Trypanosoma lewisi immune rat serum (ablastin) and injecting it into S. mansoni infected mice. These procedures were followed on days 4, 14 and 28 of S. mansoni infection. For the groups that were given immune rat serum, controls were kept into which normal rat serum was injected.

Ablastin does not have any effect on the development or morphology of the S. mansoni worms as tested in this study. Although ablastin inhibits glycolytic …

Concurrent Infections Of Trypanosoma Equiperdum And Trichinella Spiralis In Mice, Pauline A. Nembhard

Loma Linda University Electronic Theses, Dissertations & Projects

In concurrent infections of Trichinella spiralis and Trypanosoma equiperdum, the survival times vary in the early stages of the Trichinella infection. On Days 1 and 4, the mean survival times are significantly increased, and on Days 3 and 7 they are markedly decreased. This decrease is probably due to intestinal tissue invasion. Mice infected with trypanosomes after the 7th day of the Trichinella infection have survival time increases to a significant point and a steady leveling off to Day 21. It is suggested that the antibodies produced against the Trichinella worms slow down multiplication of trypanosomes and increase the …

The Life Cycle Of Lissorchis Heterorchis, Macy And Krygier (1969), Brendan P. H. Onyejekwe

Dissertations and Theses

Many Flumenicola virens (Lea) collected from Crystal Springs Creek and Tualatin River, Portland, Oregon, were found to shed large numbers of a species of microcercous cercariae containing refractile granules. They resembled the cercariae of Triganodistomum mutabile (=Lissorchis mutabile Cort, 1918 as described by Wallace (1939), and subsequent experiments proved that they were the larval stages of what was described by Macy and Krygier (1969), as Lissorchis heterorchis. Encystment of these cercariae was induced experimentally in uninfected adult brown planarians collected partly from Crystal Springs Creek and partly from Carolina Biological Research Station in Gladstone, Portland, Oregon. Adult flukes …

Infectivity And Development Of Trichinella Spiralis In Germ-Free, Monocontaminated And Conventional Mice, Daulat Sitanggang

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of the experiment was to compare the development of Trichinella spiralis in germ-free, Lactobacillus casei monocontaminated, Escherichia coli monocontaminated and conventional mice. The criteria used in the experiments were the recovery of adults and larvae of T. spiralis after 72 hours and one month post-infection, respectively. which gave an indication of the effects of no bacteria or only a certain, single species of bacterium on the development of this nematode in mice.

Germ-free T. spiralis larvae were obtained by washing them several times with sterile normal saline, and treatment with antibiotics. The gavaging procedure was done without anesthetization …

The Effect Of Gamma Irradiation On Growth Of Seven Strains Of Trypanosoma Avium, Roy Wesley Leid Jr.

All Master's Theses

The prime motivating factor in the present study was the desire to show significant differences in radio-sensitivities within six strains of Trypanosoma avium. A seventh strain was later added for the last two irradiation treatments. Gross morphology and differences in growth curves associated with varying temperatures suggested that the strains being cultured were not the same. With these differences in mind, the strains were subjected to different dosage levels of gamma irradiation.

Some Aspects Of Carbohydrate Metabolism In The Cercariae Of Schistosoma Mansoni Sambon, 1907, A. Eugene Dunham Jr.

Loma Linda University Electronic Theses, Dissertations & Projects

Cercariac of Schistosoma mansoni were studied for glycogen utilization, uptake of glucose from solution, lactic acid production, and respiration.

Using the anthrone method of determination of carbohydrate, the amount of glycogen used by a single cercaria in 4 hours is determined as 43.2 x 10^-4 μg ± 6.6 x 10^-4 μg.

Glucose was not observed to have been used from solution under the conditions of the experiment, even in the presence of trehalose. The determinations were made by the Glucostat method.

After deproteinization and desugarization, aliquots of supernatant from cercarial suspensions were analyzed for lactic acid using p-phenylphenol …

The Effect Of Varying Protein Intake On Trichinella Spiralis Infection In Mice, Clare K. Kwan

Loma Linda University Electronic Theses, Dissertations & Projects

Three hundred Swiss Webster albino mice three weeks of age were placed on low (8%), medium (24%), high (48%) protein levels and a commercial laboratory animal feed, Purina Chow for various lengths of time: (1) simultaneously with infection, and four weeks thereafter, (2) three weeks before infection and throughout the four-week infection period, and (3) six weeks prior to infection and during the infection period. The protein source was casein. Sixty of the 300 mice used served as noninfected controls, and the other 240 were each infected with 400 washed, suspended Trichinella spiralis larvae obtained from a rat by the …

Life History Of A Haemogregarine, Hepatozoon Sp. In The Chuckwalla: Sauromalus, John E. Lewis

Loma Linda University Electronic Theses, Dissertations & Projects

[Abstract Not Included]

Natural History Of Thelazia Californiensis Price, 1930 (Nematoda: Thelaziidae), A Mammalian Eye Worm, Warren E. Parmelee

Loma Linda University Electronic Theses, Dissertations & Projects

Various factors—embryology, host associations, and seasonal changes In eye worn populations—tending to promote the propagation of T. califomlensls were studied.

The early embryology closely parallels that of other nematode species.

The mature embryos remain alive in saline at 35°C as long as 5 days. Dead embryos can be distinguished from living ones by virtue of the rapid staining by methylene blue by the former. Parturient female thelazias release embryos into saline, and embryos are found regularly in tear secretions of infected laboratory rabbits.

Ovic embryos possess an enveloping egg membrane containing chitin. On this account, this eye worm species is …

Natural And Experimental Infections Of Thelazia Californiensis Price (1930, Nematoda: Thelaziidae) With Descriptions Of The Adult And Larval Parasites, Howard S. Burnett

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this work was to determine the extent and effects of infestation of the eye worm of mammals, Thelazia californiensis, and to elucidate through experimentation or observation the mode of transmission.

A survey of literature revealed that thelaziasie (infestation by Thelazia species) may cause serious pathological changes in the eye and its adnexa, sometimes resulting in blindness. It was found that reports of thelaziasis in the United States were (with two exceptions) of cases in California. It was further found that T. californiensis has been reported in a wider variety of host than has any of other …