99 research outputs found
Muehlenbachs 2
No full textDr. Karlis Muehlenbachs, University of Alberta professor and researcher in the Faculty of Earth and Atmospheric Science
Maternal-fetal conflict during placental malaria: hypertension, trophoblast sVEGFR1 expression and maternal inflammation
No full textThesis (Ph. D.)--University of Washington, 2006.The maternal-fetal relationship is hypothesized to be in genetic conflict over nutrient allocation. Fetal mechanisms that elevate maternal blood pressure increase blood flow to the placenta, nourishing the fetus. This relationship becomes pathological during hypertensive diseases in pregnancy, such as preeclampsia. During placental malaria, a third organism, Plasmodium falciparum , occupies the maternal side of the placenta, and maternal inflammation ensues which results in low birth weight. Both placental malaria and preeclampsia are more common during first pregnancies. This dissertation examines the maternal fetal relationship during placental malaria, specifically regarding maternal blood pressure. Chapter 1 is a review of the literature. Chapter 2 presents the epidemiology of placental malaria and hypertension based on data collected from the Mother Offspring Malaria Project in Muheza, Tanzania. Chapter 3 presents data that placental malaria involves vascular endothelial growth factor (VEGF) and its soluble inhibitor sVEGFR1, a preeclampsia biomarker. Chapter 4 characterizes the maternal inflammatory response in placental malaria, and finds correlation with sVEGFR1 expression.In summation these chapters present data that hypertension occurs in first time mothers with chronic placental malaria, and that genetic conflict occurs between mother and fetus during placental malaria, whereby maternal macrophages in the placenta express the proinflammatory mediator VEGF, and the fetal trophoblast expresses its soluble inhibitor sVEGFR1. Because placental inflammation causes poor fetal outcomes, fetal mechanisms that promote sVEGFR1 expression may be under selective pressure in malaria endemic areas, particularly during first pregnancies, and may have influenced the evolution of preeclampsia
J Cutan Pathol
No full textFree-living amebae are ubiquitous in our environment, but rarely cause cutaneous infection. Balamuthia mandrillaris has a predilection for infecting skin of the central face. Infection may be restricted to the skin or associated with life-threatening central nervous system (CNS) involvement. We report a case of a 91-year-old woman, who presented with a non-healing red plaque over her right cheek. Several punch biopsies exhibited non-specific granulomatous inflammation without demonstrable fungi or mycobacteria in histochemical stains. She was treated empirically for granulomatous rosacea, but the lesion continued to progress. A larger incisional biopsy was performed in which amebae were observed in hematoxylin-eosin stained sections. These were retrospectively apparent in the prior punch biopsy specimens. Immunohistochemistry and polymerase chain reaction studies identified the organisms as Balamuthia mandrillaris. Cutaneous infection by B. mandrillaris is a rare condition that is sometimes complicated by life-threatening CNS involvement and which often evades timely diagnosis due to its rarity and nonspecific clinical manifestations. Moreover, these amebae are easily overlooked in histopathologic sections because of their small number and their resemblance to histiocytes. Dermatopathologists should be familiar with the histopathologic appearance of these organisms and include balamuthiasis and other amebic infections in the differential diagnosis of granulomatous dermatitis.CC999999/Intramural CDC HHSUnited States
J Histotechnol
No full text, a bacterial tickborne pathogen that causes Rocky Mountain spotted fever (RMSF), stains poorly or not at all with conventional tissue Gram techniques, and contemporary visualization of the pathogen in formalin-fixed, paraffin-embedded tissues has relied almost entirely on immunohistochemical staining methods that are generally limited to specialized research laboratories or national reference centers. To our knowledge, previously described argyrophil-based histochemical techniques have not successfully detected rickettsiae in formalin-fixed, paraffin-embedded tissues. To investigate the ability of standard silver impregnation techniques to demonstrate the occurrence and distribution of | in tissues of patients with RMSF confirmed by molecular and immunohistochemical methods, three widely recognized and commercially available silver impregnation methods (Warthin-Starry, Steiner, and Dieterle's) were applied to various tissues obtained at autopsy from 10 patients with fatal RMSF. | bacteria were demonstrated in one or more tissues of all patients, using each of the argyrophil-based methods, and appeared as small, dark brown-to-black lanceolate rods, often in pairs and occasionally surrounded by a faint halo. Rickettsiae were identified most consistently in small arteries and arterioles of liver, kidney, and leptomeninges, and were localized predominantly to the cytoplasm of endothelial cells and less often within the internal elastic lamella and smooth muscle of the media. This validation of argyrophilic techniques to detect | demonstrates the utility of inexpensive core histochemical methods in the diagnosis of infectious agents in pathology specimens and may have utility in certain resource-limited settings where RMSF is endemic.CC999999/ImCDC/Intramural CDC HHSUnited States
An unusual presentation of placental malaria: a single persisting nidus of sequestered parasites.
No full textPlacental malaria caused by Plasmodium falciparum is a public health concern in tropical countries. Peripheral blood smears to detect placental malaria are often negative, and recrudescences are common during pregnancy. We performed placental histology on a series of first-time mothers delivering in an area endemic for P falciparum. A single nidus of malaria-infected erythrocytes was identified by placental histology in a single intervillous space from a woman who had no other evidence of peripheral or placental blood parasitemia. This finding suggests ring stage-infected erythrocytes sequester in vivo, or P falciparum can persist as a dormant blood stage form
BMJ Glob Health
No full textBackgroundThe control of malaria in pregnancy (MiP) in India relies on testing women who present with symptoms or signs suggestive of malaria. We hypothesised that intermittent screening and treatment for malaria at each antenatal care visit (ISTp) would improve on this approach and reduce the adverse effects of MiP.MethodsA cluster randomised controlled trial comparing ISTp versus passive case detection (PCD) was conducted in Jharkhand state. Pregnant women of all parities with a gestational age of 18\u201328 weeks were enrolled. Women in the ISTp group were screened with a rapid diagnostic test (RDT) for malaria at each antenatal clinic visit and those in the PCD group were screened only if they had symptoms or signs suggestive of malaria. All RDT positive women were treated with artesunate/sulfadoxine\u2013pyrimethamine. The primary endpoint was placental malaria, determined by placental histology, and the key secondary endpoints were birth weight, gestational age, vital status of the newborn baby and maternal anaemia.ResultsBetween April 2012 and September 2015, 6868 women were enrolled; 3300 in 46 ISTp clusters and 3568 in 41 PCD clusters. In the ISTp arm, 4.9% of women were tested malaria positive and 0.6% in the PCD arm. There was no difference in the prevalence of placental malaria in the ISTp (87/1454, 6.0%) and PCD (65/1560, 4.2%) groups (6.0% vs 4.2%; OR 1.34, 95%\u2009CI 0.78 to 2.29, p=0.29) or in any of the secondary endpoints.ConclusionISTp detected more infections than PCD, but monthly ISTp with the current generation of RDT is unlikely to reduce placental malaria or impact on pregnancy outcomes. ISTp trials with more sensitive point-of-care diagnostic tests are needed.201931406586PMC66668121166
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