Jonathan Stiles
Morehouse School of Medicine, MBI, Faculty Member
The Research Centers in Minority Institutions (RCMI) Program was congressionally mandated in 1985 to build research capacity at institutions that currently and historically recruit, train, and award doctorate degrees in the health... more
The Research Centers in Minority Institutions (RCMI) Program was congressionally mandated in 1985 to build research capacity at institutions that currently and historically recruit, train, and award doctorate degrees in the health professions and health-related sciences, primarily to individuals from underrepresented and minority populations. RCMI grantees share similar infrastructure needs and institutional goals. Of particular importance is the professional development of multidisciplinary teams of academic and community scholars (the “workforce”) and the harnessing of the heterogeneity of thought (the “thinkforce”) to reduce health disparities. The purpose of this report is to summarize the presentations and discussion at the RCMI Investigator Development Core (IDC) Workshop, held in conjunction with the RCMI Program National Conference in Bethesda, Maryland, in December 2019. The RCMI IDC Directors provided information about their professional development activities and Pilot Pr...
Research Interests:
In malaria endemic countries, anemia in pregnant women occurs as a result of erythrocyte destruction by Plasmodium infections and other causes including malnutrition. Iron supplementation is recommended as treatment of iron-deficiency... more
In malaria endemic countries, anemia in pregnant women occurs as a result of erythrocyte destruction by Plasmodium infections and other causes including malnutrition. Iron supplementation is recommended as treatment of iron-deficiency anemia. Erythrocyte destruction results in increased release of cytotoxic free heme that is scavenged by haptoglobin (Hp), hemopexin (Hx) and heme oxygenase-1 (HO-1). Paradoxically, iron supplementation in pregnant women has been reported to enhance parasitemia and increase levels of free heme. The relationship between free heme, heme scavengers, and birth outcomes has not been investigated, especially in women who are on iron supplementation. We hypothesized that parasite-infected pregnant women on routine iron supplementation have elevated heme and altered expression of heme scavengers. A cross-sectional study was conducted to determine the association between plasma levels of free heme, HO-1, Hp, Hx, and malaria status in pregnant women who received...
Research Interests:
BACKGROUND: Vasculogenesis is critically important to restoring and maintaining vascular homeostasis in patients who have sickle cell disease. Emerging evidence indicates vasculo-angiogenesis is a complex process involving recruitment of... more
BACKGROUND: Vasculogenesis is critically important to restoring and maintaining vascular homeostasis in patients who have sickle cell disease. Emerging evidence indicates vasculo-angiogenesis is a complex process involving recruitment of endothelial progenitor cells (EPCs) from the bone marrow and homing of EPCs to sites of vascular injury. Both recruitment and homing of EPCs are intimately regulated by cytokines and growth factors that are released in response to vascular insult. Hitherto, the phenotype of growth factors and cytokines intimately involved in EPC recruitment and homing in patients who have sickle cell disease remains poorly understood. METHODS: A total of 50 children aged 6–18 years were studied, 30 with Hemoglobin SS, including 11 on chronic red blood cell transfusions, and 20 with normal hemoglobin. We measured plasma concentrations of angiogenesis growth factors/cytokines using a multiplex assay, which permitted analysis of nine factors concurrently, and determine...
Research Interests:
In Africa, the natural history of SCD is often assumed to be same to the African Diaspora in the US, Jamaica, Europe or Latin America. Yet the environment can be different, including different pathogen exposure, such as malaria. To help... more
In Africa, the natural history of SCD is often assumed to be same to the African Diaspora in the US, Jamaica, Europe or Latin America. Yet the environment can be different, including different pathogen exposure, such as malaria. To help better understand this, over 2000 references were identified using the names of all current or past names of African continent countries and the truncated word sickl$, followed by secondary nested and cross reference searches. Six cases series describing causes of death were identified, representing 182 children (Ndugwa, 1973, Athale, 1994, Koko, 1998, Diagne, 2000, Rahimy, 2003, Van-Dunem, 2007). Gender was reported in 172, 73 were female (42%). Age was reported in 118, 52 were < 5 years (44%). Four studies described some impediment to care or arrival for care in extremis in1/4 to over ½ of patients that died. In Uganda, 9/12 (75%) patient died at home. In Gabon 6/23 (26%) patients died within 4 hours of reaching the hospital and 11/23 (48%) with...
Research Interests:
2123 Little is known about the relative rate of pubertal development among children with different phenotypes of sickle cell disease (SCD). This study proposes, for the first time, to compare the influence of SCD phenotypes on pubertal... more
2123 Little is known about the relative rate of pubertal development among children with different phenotypes of sickle cell disease (SCD). This study proposes, for the first time, to compare the influence of SCD phenotypes on pubertal development (PD) and body mass. We hypothesized that differences in pubertal development and body mass index (BMI) are modulated by SCD phenotype and treatment modality. We therefore conducted a cross-sectional study of SCD children and adolescents aged 8 – 18 years old (yo) to determine the impact of SCD phenotype and treatments on pubertal development (according to sexual maturity rating by Tanner stages, TS) and BMI. Participants were recruited from…
Research Interests:
BackgroundMalaria mortality is associated with exaggerated host responses to inflammatory factors such as C-X-C motif chemokine 10 (CXCL10) and host biomarkers such as angiopoietin 1 (Ang-1) and angiopoietin 2 (Ang-2). The aim of this... more
BackgroundMalaria mortality is associated with exaggerated host responses to inflammatory factors such as C-X-C motif chemokine 10 (CXCL10) and host biomarkers such as angiopoietin 1 (Ang-1) and angiopoietin 2 (Ang-2). The aim of this study was to determine saliva levels of CXCL10, Ang-1 and Ang-2 and compare with plasma levels regarding their potential as biomarkers of malaria, which may be useful for further development of highly efficient non-invasive malaria detection methods.MethodsCase control study involving 213 subjects (119 with and 94 without malaria) aged 1–16 years. Haematological determination was done using Haematology Analyser. Plasmodium Lactate Dehydrogenase/Histidine Rich Protein-2 (pLDH/HRP-2) Antigen rapid diagnostic test (RDT) were performed. Plasma and saliva levels of CXCL10, Ang-1 and Ang-2 were measured using Elisa kit. Data was presented as mean ±standard error or median and interquartile range (IQR). A p-value<0.001 was considered statistically signific...
Research Interests:
Junior investigators often have limited access to networks of scientific experts and resources that facilitate competitive grant submissions. Since environments in which scientists are trained are critically important for long-term... more
Junior investigators often have limited access to networks of scientific experts and resources that facilitate competitive grant submissions. Since environments in which scientists are trained are critically important for long-term success, we built and tested a virtual environment for early-stage investigators (ESIs) working on grant proposals. The aim of this study was to evaluate the virtual community’s influence on grant submission patterns among participants from underrepresented groups. As part of a grant writing coaching model, junior investigators were recruited into a professional development program designed to develop competitive grantsmanship skills. Designed by the Research Resources and Outreach Core (RROC) of the National Research Mentoring Network (NRMN), the Health Equity Learning Collaboratory (EQ-Collaboratory) provided a virtual community for social support, accountability, constructive feedback, and access to peer networks to help investigators overcome barriers...
Research Interests:
Human cerebral malaria (HCM) is a severe form of malaria characterized by sequestration of infected erythrocytes (IRBCs) in brain microvessels, increased levels of circulating free heme and pro-inflammatory cytokines and chemokines, brain... more
Human cerebral malaria (HCM) is a severe form of malaria characterized by sequestration of infected erythrocytes (IRBCs) in brain microvessels, increased levels of circulating free heme and pro-inflammatory cytokines and chemokines, brain swelling, vascular dysfunction, coma, and increased mortality. Neuregulin-1β (NRG-1) encoded by the gene NRG1, is a member of a family of polypeptide growth factors required for normal development of the nervous system and the heart. Utilizing an experimental cerebral malaria (ECM) model (Plasmodium berghei ANKA in C57BL/6), we reported that NRG-1 played a cytoprotective role in ECM and that circulating levels were inversely correlated with ECM severity. Intravenous infusion of NRG-1 reduced ECM mortality in mice by promoting a robust anti-inflammatory response coupled with reduction in accumulation of IRBCs in microvessels and reduced tissue damage. In the current study, we examined how NRG-1 treatment attenuates pathogenesis and mortality associa...
Research Interests:
Effective mentorship is critical to the success of early stage investigators, and has been linked to enhanced mentee productivity, self-efficacy, and career satisfaction. The mission of the National Research Mentoring Network (NRMN) is to... more
Effective mentorship is critical to the success of early stage investigators, and has been linked to enhanced mentee productivity, self-efficacy, and career satisfaction. The mission of the National Research Mentoring Network (NRMN) is to provide all trainees across the biomedical, behavioral, clinical, and social sciences with evidence-based mentorship and professional development programming that emphasizes the benefits and challenges of diversity, inclusivity, and culture within mentoring relationships, and more broadly the research workforce. The purpose of this paper is to describe the structure and activities of NRMN. NRMN serves as a national training hub for mentors and mentees striving to improve their relationships by better aligning expectations, promoting professional development, maintaining effective communication, addressing equity and inclusion, assessing understanding, fostering independence, and cultivating ethical behavior. Training is offered in-person at institu...
Research Interests:
Research Interests:
Chronic inflammation is a characteristic of sickle cell disease (SCD), and is invariably associated with vascular endothelial injury. Hydroxyurea (HU), a naturally cytotoxic chemotherapeutic agent, is the only FDA drug approved for SCD,... more
Chronic inflammation is a characteristic of sickle cell disease (SCD), and is invariably associated with vascular endothelial injury. Hydroxyurea (HU), a naturally cytotoxic chemotherapeutic agent, is the only FDA drug approved for SCD, and is therefore naturally cytotoxic. Quercetin (QCT) is a dietary flavonoid found ubiquitously in plants and foods that have anti-oxidative and anti-inflammatory characteristics. Our hypothesis is that dietary QCT will decrease cytotoxic effects of lipopolysaccharide (LPS) and HU induced vascular cell damage. Lipopolysaccharide (LPS) was used to induce inflammation in immortalized mouse aortic endothelial cells (iMAECs), providing an in vitro model of inflamed endothelial cells. The cells were exposed to LPS throughout the entire experiment. Interventions included treating the LPS exposed cells with QCT, HU, or QCT + HU over 50 hours. The 50-hour period included 24 hours of varying treatments, followed by two hours of hypoxic exposure and then 24 ho...
Iron supplementation is recommended for pregnant women to meet their iron requirement for a healthy pregnancy. The benefits and risks of universal iron supplementation during pregnancy in malaria endemic countries are currently being... more
Iron supplementation is recommended for pregnant women to meet their iron requirement for a healthy pregnancy. The benefits and risks of universal iron supplementation during pregnancy in malaria endemic countries are currently being debated. As part of a broader study that focused on the effect of heme/HO-1 on pregnancy outcomes in malaria in pregnancy, we determined the association between iron supplementation and free heme levels in blood of pregnant women with and without malaria in Ghana. We hypothesized that pregnant women with malaria who took iron supplements will have higher levels of Heme/HO-1 than those who did not take iron supplements. A total of 337 women were recruited for this study. Blood samples were collected for malaria diagnosis and heme/HO-1 measurement. Quantification of heme was done using a heme colorimetric assay kit and HO-1 levels were performed using Enzyme-Linked Immunosorbent Assay (ELISA) on plasma samples. Malaria positive iron supplemented women, in...
Research Interests:
Scarce studies have addressed hematological differences of malaria in urban and rural regions. Full or complete blood cell counts from 46 and 75 individuals (age range from < 1 to 92 years) with uncomplicated malaria infection living... more
Scarce studies have addressed hematological differences of malaria in urban and rural regions. Full or complete blood cell counts from 46 and 75 individuals (age range from < 1 to 92 years) with uncomplicated malaria infection living in urban (Accra) and rural (Dodowa) Ghana, respectively, were assessed. Sickle cell trait and patients were excluded from the study. Between overall groups, patients from Accra had significantly lower parasite count (p < 0.0001) and granulocyte number (p = 0.026). Children in Accra had a significantly lower parasitemia (p = 0.0013), hemoglobin (p = 0.0254), platelet count (p = 0.0148) and red blood cell levels (p = 0.0080) when compared with the children of Dodowa. In adults, mean cell hemoglobin (p = 0.0086) and parasite count (p < 0.0001) were significantly higher in Dodowa. These results indicate that children living in urban setting may experience a greater anemic effect to malaria as compared with those living in a rural setting.
Research Interests:
Research Interests:
Research Interests:
Prohibitin is a ubiquitous and highly conserved protein implicated as an important regulator in cell survival. Prohibitin content is inversely associated with cell proliferation, but it increases during granulosa cell differentiation as... more
Prohibitin is a ubiquitous and highly conserved protein implicated as an important regulator in cell survival. Prohibitin content is inversely associated with cell proliferation, but it increases during granulosa cell differentiation as well as in earlier events of apoptosis in a temperature-sensitive granulosa cell line. In the present study, we have characterized the spatial expression patterns for prohibitin using established in vivo models for the induction of follicular development and atresia in the mammalian ovary. Comparative Western blot analyses of granulosa cell lysates from control ovaries and from ovaries primed with eCG or treated with eCG plus anti-eCG (gonadotropin withdrawal) were conducted. Prohibitin was immunolocalized in rat ovarian sections probed with antibodies against either proliferating cell nuclear antigen (PCNA) or cholesterol side-chain cleavage cytochrome P450 (P450(scc)) or in terminal deoxynucleotidyl transferase-mediated dUTP nick end labeled sections. Additionally, porcine oocytes, zygotes, and blastocyts were also immunolocalized with prohibitin antibody. Immunolocalization revealed the presence of prohibitin in granulosa cells, theca-interstitial cells, and the oocyte. The results indicate that prohibitin protein expression in the gonadotropin-treated cells was upregulated. Immunoreactivity of prohibitin was inversely related to PCNA expression during follicular maturation and colocalized with P450(scc). Prohibitin appeared to be translocated from the cytoplasm to the nucleus in atretic follicles, germinal vesicle-stage oocytes, zygotes, and blastocysts. These results suggest that prohibitin has several functional regulatory roles in granulosa and theca-interstitial cells and in the ovum during follicular maturation and atresia. It is likely that prohibitin may play an important role in determining the fate of these cells and eventual follicular destiny.
Research Interests:
In the sterile insect technique, insects are sterilized prior to release in areas where they are pests. The sterile males compete for and with fertile wild individuals for mates, thus reducing the population&#39;s reproductive rate.... more
In the sterile insect technique, insects are sterilized prior to release in areas where they are pests. The sterile males compete for and with fertile wild individuals for mates, thus reducing the population&#39;s reproductive rate. Tsetse fly (Glossina spp.) populations have been eradicated after release of laboratory-bred flies sterilized by gamma irradiation. However, no studies exist on radiation-induced damage to the midgut morphology and function of the radiation-sterilized insects. After G. palpalis palpalis and G. p. gambiensis were subjected to 130 Gy gamma radiation, their midgut damage and recovery were monitored by electron microscopy. The first sign of damage was atrophy and loss of the microvillous border from epithelial cells. The rate of cell degeneration increased, with young as well as old cells being affected and cellular debris filling the ectoperitrophic space. Muscle cells were destroyed, patches of basal lamina were left bare, intracellular virus- and rickettsia-like organisms became more frequent, and many replacement cells became unusually large. Partial recovery occurred from the 10th day postirradiation. Such changes in midgut ultrastructure and the corresponding inhibition of functions may increase the susceptibility of the fly to trypanosome infection.
Research Interests: Radiation, Electron Microscopy, Gamma Rays, Biological Sciences, Electromagnetic Radiation, and 15 moreAnimals, Sterile Insect Technique, Physical sciences, Sterilization, Pest control, Digestive System, Radiation Effect, Degeneration, Biological Pest Control, Ionizing Radiation, Epithelial Cell Biology, Gamma Irradiation, Gamma radiation, Tsetse Flies, and Medical and Health Sciences
Research Interests:
Intermittent preventive treatment with sulphadoxine-pyrimethane (IPTp-SP) is currently the recommended regimen for prevention of malaria in pregnancy in endemic areas. However, the effectiveness of this approach in preventing malaria and... more
Intermittent preventive treatment with sulphadoxine-pyrimethane (IPTp-SP) is currently the recommended regimen for prevention of malaria in pregnancy in endemic areas. However, the effectiveness of this approach in preventing malaria and anemia in pregnant women is unclear. The objective of the study was to evaluate the effectiveness of IPTp-SP in preventing malaria and anemia among pregnant women attending antenatal clinic (ANC) at Korle-Bu Teaching Hospital (KBTH), Accra, Ghana. A cross-sectional study comparing malaria and anemia incidence among pregnant women using IPTp-SP with those not using IPTp was conducted. 363 pregnant women were recruited of which 202 were using IPTp and 161 were IPTp non-users. Malaria parasites and hemoglobin levels (Hb < 11g/dl) were determined. Thirty-one (15.3%) women using IPTp had malaria compared to 72 (44.7%) of women who did not use IPTp (protective efficacy 74%, p < 0.001). The number of anemic women not utilizing IPTp was significantly ...
Research Interests:
Human African trypanosomiasis is a neglected disease caused by Trypanosoma brucei spp. A parasite cation pump (Ca(2+) ATPase; TBCA2) essential for survival and cation homeostasis was identified and characterized. It was hypothesized that... more
Human African trypanosomiasis is a neglected disease caused by Trypanosoma brucei spp. A parasite cation pump (Ca(2+) ATPase; TBCA2) essential for survival and cation homeostasis was identified and characterized. It was hypothesized that targeting this pump using a Vibrio cholerae ghost (VCG)-based vaccine could protect against murine T. brucei infection. mRNA and protein expression of TBCA2 was differentially expressed in blood and insect stages of parasites and immunolocalized in the pericellular membrane and the flagellar pocket of bloodstream forms. Antigen-specific antibodies and Th1 cytokines, interleukin-2, interferon-gamma, and tumor necrosis factor-alpha were induced in rVCG-TBCA2-immunized mice and in vitro on antigen stimulation of splenic immune T cells, but the corresponding Th2-type response was unremarkable. Despite an increased median survival of 6 days in vaccinated mice, the mice were not protected against infection. Thus, immunization of mice produced robust paras...
Research Interests:
Detection of Plasmodium falciparum parasites in patients with malaria necessitates drawing blood, which increases the risk of accidental infections and is poorly accepted in communities with blood taboos. Thus, non-invasive,... more
Detection of Plasmodium falciparum parasites in patients with malaria necessitates drawing blood, which increases the risk of accidental infections and is poorly accepted in communities with blood taboos. Thus, non-invasive, cost-effective malaria tests that minimize the need for blood collection are needed. Plasmodium falciparum histidine-rich protein II (PfHRP II) levels in plasma and saliva were compared in malaria-positive and -negative patients in Ghana. Plasma and saliva obtained from 30 thick-film positive and 10 negative children were evaluated for PfHRP II by ELISA. Among the 30 children with positive blood smear, 16 (53%) were PfHRP II positive in plasma and 13 (43%) had PfHRP II positive saliva. The sensitivity of PfHRP II detection was 53% for plasma and 43% for saliva. The specificity was 100% with no false positive for both plasma and saliva when compared with blood smear. Thus, rapid detection of PfHRP II antigen in saliva may be a useful non-invasive and cost-effecti...
Research Interests:
Subtyping isolates of Trichomonas vaginalis is an essential tool for understanding the epidemiology of this common sexually-transmitted disease. Restriction fragment length polymorphism (RFLP) analysis employing a probe from the... more
Subtyping isolates of Trichomonas vaginalis is an essential tool for understanding the epidemiology of this common sexually-transmitted disease. Restriction fragment length polymorphism (RFLP) analysis employing a probe from the heat-inducible cytoplasmic HSP70 gene family hybridized with EcoR I-digested genomic DNA was used in the molecular typing of Trichomonas isolates. Analysis of five American Type Culture Collection (ATCC) reference strains and 31 Jackson, Mississippi, isolates from six male and 21 female patients, revealed 10 distinct RFLP pattern subtypes of Trichomonas. The subtypes were temporally stable and cosmopolitan. The RFLP profiles seen in Maryland, Ohio, Massachusetts, and New York ATCC strains were identical to those of some Mississippi isolates, even though the samples were isolated 10-35 years apart. There was no correlation between metronidazole resistance and RFLP subtype with resistant isolates from eight patients distributed among six different subtypes.
Research Interests: Medical Microbiology, Molecular typing, Humans, Female, Animals, and 11 moreDrug Resistance, Male, Trichomonas vaginalis, Genomic DNA, Public health systems and services research, Gene Family, Sexually Transmitted Disease, Metronidazole, The American, DNA Restriction Enzymes, and Medical and Health Sciences
Research Interests:
Research Interests:
Over recent years there has been an increasing interest in the interaction between Trypanosomatids and in particular the genera Trypanosoma and Leishmania and their vectors. These studies on the "vector parasite interface" have... more
Over recent years there has been an increasing interest in the interaction between Trypanosomatids and in particular the genera Trypanosoma and Leishmania and their vectors. These studies on the "vector parasite interface" have been wide ranging but often suffer from the difficulties of manipulating some of the vector systems. It is now likely that molecular biological and protein analysis techniques can be more effectively applied in dissecting these interactions with a view to identification and characterisation of molecules which control parasite behaviour in vectors. This presentation will review recent studies on Glossina lectins in relation to trypanosome behaviour in flies including recent studies on different G. palpalis subspecies as well as review evidence that trypanosomatids have an effect on their insect hosts for example, on feeding behaviour, susceptibility to insecticides and longevity of infected vectors. Sugars are known to influence development and trans...
Research Interests:
Key pathophysiology of sickle cell anaemia includes compensatory erythropoiesis, vascular injury and chronic inflammation, which divert amino acids from tissue deposition for growth/weight gain and muscle formation. We hypothesised that... more
Key pathophysiology of sickle cell anaemia includes compensatory erythropoiesis, vascular injury and chronic inflammation, which divert amino acids from tissue deposition for growth/weight gain and muscle formation. We hypothesised that sickle mice maintained on an isoenergetic diet with a high percentage of energy derived from protein (35 %), as opposed to a standard diet with 20 % of energy derived from protein, would improve body composition, bone mass and grip strength. Male Berkeley transgenic sickle mice (S; n 8–12) were fed either 20 % (S20) or 35 % (S35) diets for 3 months. Grip strength (BIOSEB meter) and body composition (dual-energy X-ray absorptiometry scan) were measured. After 3 months, control mice had the highest bone mineral density (BMD) and bone mineral content (BMC) (P < 0·005). S35 mice had the largest increase in grip strength. A two-way ANOVA of change in grip strength (P = 0·043) attributed this difference to genotype (P = 0·025) and a trend in type of die...
Research Interests:
Sickle cell disease is associated with hypermetabolism and a consequent shortage of substrates for normal growth and healthy immune response. The protein:energy ratio is a major determinant of dietary adequacy; the requirement for optimal... more
Sickle cell disease is associated with hypermetabolism and a consequent shortage of substrates for normal growth and healthy immune response. The protein:energy ratio is a major determinant of dietary adequacy; the requirement for optimal growth of control mice is 20% of energy from dietary protein. This study investigated the efficacy of increased dietary protein for improving weight gain and reducing inflammation in the Berkeley sickle cell mouse model (S). The study examined the effect of diet on weight gain and circulating levels of 2 inflammatory proteins, C-reactive protein (CRP), and cytokine interleukin-6 (IL-6). Male C57BL/6 (C) control (n = 8) and S mice (n = 8) were randomized at weaning to 40 d of isoenergetic diets containing 20% (normal) and 35% (high) of energy from protein (C20, C35, S20, S35), replacing dextrin. Rate of weight gain was calculated and plasma CRP and IL-6 concentrations determined by ELISA. Liver mRNA expression of these proteins was measured by real-...
Research Interests: Nutrition and Dietetics, Nutrition, Immune response, Animal Production, Liver, and 15 moreMice, Nitric oxide, Animals, C reactive protein, mRna expression levels, Mouse Model, Arginine, Food Sciences, Optimal Growth, Dietary Protein, Cross Sectional Studies, Gene Expression Regulation, Interleukin, Random Allocation, and High protein
Restriction fragment length polymorphism (RFLP) analysis using a multilocus heat-inducible cytoplasmic heat-shock protein 70 (Hsp70) hybridization probe with EcoRI-digested genomic DNA was used in molecular typing of 129 Trichomonas... more
Restriction fragment length polymorphism (RFLP) analysis using a multilocus heat-inducible cytoplasmic heat-shock protein 70 (Hsp70) hybridization probe with EcoRI-digested genomic DNA was used in molecular typing of 129 Trichomonas vaginalis isolates. Results indicate that Trichomonas organisms exhibit considerable polymorphism in their Hsp70 RFLP patterns. Analysis of seven American Type Culture Collection reference strains and 122 clinical isolates, including 84 isolates from Jackson, Mississippi, 18 isolates from Atlanta, Georgia, and 20 isolates from throughout the United States, showed 105 distinct Hsp70 RFLP pattern subtypes for Trichomonas. Phylogenetic analysis of the Hsp70 RFLP data showed that the T. vaginalis isolates were organized into two clonal lineages. These results illustrate the substantial genomic diversity present in T. vaginalis and indicate that a large number of genetically distinct Trichomonas isolates may be responsible for human trichomoniasis in the Unit...
Research Interests: Genetics, Polymorphism, China, Genetic Diversity, Phylogeny, and 15 moreMolecular typing, Humans, Female, Animals, Male, Polymerase Chain Reaction, Cluster Analysis, Phylogenetic analysis, Genomic DNA, Adult, Genetic variation, Heat Shock Protein, The American, Pattern analysis, and Medical and Health Sciences
Research Interests:
Research Interests: Medical Microbiology, Malaria, Ghana, Cerebrospinal Fluid, Humans, and 15 moreChild, Female, Male, Infant, Plasmodium falciparum, Prognosis, Immunoassay, Biological markers, Cerebral Malaria, Biomarkers of Cerebral Malaria, CSF biomarkers of cerebral malaria, Enzyme Linked Immunosorbent Assay, Interleukin, Fas Ligand, and Child preschool
Research Interests:
Detection of Plasmodium falciparum parasites in patients with malaria necessitates drawing blood, which increases the risk of accidental infections and is poorly accepted in communities with blood taboos. Thus, non-invasive,... more
Detection of Plasmodium falciparum parasites in patients with malaria necessitates drawing blood, which increases the risk of accidental infections and is poorly accepted in communities with blood taboos. Thus, non-invasive, cost-effective malaria tests that minimize the need for blood collection are needed. Plasmodium falciparum histidine-rich protein II (PfHRP II) levels in plasma and saliva were compared in malaria-positive and -negative patients in Ghana. Plasma and saliva obtained from 30 thick-film positive and 10 negative children were evaluated for PfHRP II by ELISA. Among the 30 children with positive blood smear, 16 (53%) were PfHRP II positive in plasma and 13 (43%) had PfHRP II positive saliva. The sensitivity of PfHRP II detection was 53% for plasma and 43% for saliva. The specificity was 100% with no false positive for both plasma and saliva when compared with blood smear. Thus, rapid detection of PfHRP II antigen in saliva may be a useful non-invasive and cost-effecti...