Morphological features and differential counts of Plasmodium knowlesi parasites in naturally acquired human infections

Background: Human infections with Plasmodium knowlesi, a simian malaria parasite, are more common than previously thought. They have been detected by molecular detection methods in various countries in Southeast Asia, where they were initially diagnosed by microscopy mainly as Plasmodium malariae and at times, as Plasmodium falciparum. There is a paucity of information on the morphology of P. knowlesi parasites and proportion of each erythrocytic stage in naturally acquired human infections. Therefore, detailed descriptions of the morphological characteristics and differential counts of the erythrocytic stages of P. knowlesi parasites in human infections were made, photographs were taken, and morphological features were compared with those of P. malariae and P. falciparum. Methods: Thick and thin blood films were made prior to administration of anti-malarial treatment in patients who were subsequently confirmed as having single species knowlesi infections by PCR assays. Giemsa-stained blood films, prepared from 10 randomly selected patients with a parasitaemia ranging from 610 to 236,000 parasites per mu l blood, were examined. Results: The P. knowlesi infection was highly synchronous in only one patient, where 97% of the parasites were at the late trophozoite stage. Early, late and mature trophozoites and schizonts were observed in films from all patients except three; where schizonts and early trophozoites were absent in two and one patient, respectively. Gametocytes were observed in four patients, comprising only between 1.2 to 2.8% of infected erythrocytes. The early trophozoites of P. knowlesi morphologically resemble those of P. falciparum. The late and mature trophozoites, schizonts and gametocytes appear very similar to those of P. malariae. Careful examinations revealed that some minor morphological differences existed between P. knowlesi and P. malariae. These include trophozoites of knowlesi with double chromatin dots and at times with two or three parasites per erythrocyte and mature schizonts of P. knowlesi having 16 merozoites, compared with 12 for P. malariae. Conclusion: Plasmodium knowlesi infections in humans are not highly synchronous. The morphological resemblance of early trophozoites of P. knowlesi to P. falciparum and later erythrocytic stages to P. malariae makes it extremely difficult to identify P. knowlesi infections by microscopy alone.Publisher PDFPeer reviewe

The Role of the Vestibular and Proprioceptive Systems in Processing Dynamic Sound Localization Cues

Head movements are known to be beneficial during sound localization because the auditory system can integrate the dynamic cues generated by head movement while maintaining a spatial representation of the position and orientation of the head-in-space. To measure the extent to which vestibular and proprioceptive cues influence processing of dynamic sound localization cues resulting from head rotation, we measured the ability of normally hearing listeners to localize front/back sources of low-frequency sounds while the two modalities were individually or congruently stimulated. Targets were presented over headphones during head rotations using virtual auditory space methods. Dynamic localization cues corresponded to head-in-space and/or head-on-body angle. Discrimination was accurate in passive and active head rotation conditions, but near chance in conditions lacking head-in-space motion, suggesting that among the two sensorimotor cues, vestibular inputs are necessary and sufficient to inform the auditory system about head movement, whereas proprioceptive cues are neither necessary nor sufficient

Cyclooxygenase-2 Expression in Post-Mastectomy Chest Wall Relapse

The purpose of this study was to assess the prognostic significance and clinical correlations of cyclooxgenase-2 expression (COX) in a cohort of patients treated with radiation (RT) for post-mastectomy chest wall relapse (PMCWR). Between 1975 and 1999, 113 patients were treated for isolated PMCWR. All patients were treated with biopsy and/or excision of the CWR followed by RT. Median follow-up was 10 years. All clinical data including demographics, pathology, staging, receptor status, HER-2/neu status, and adjuvant therapy were entered into a computerized database. Paraffin-embedded CWR specimens were retrieved from 42 patients, of which 38 were evaluated, created into a tissue microarray, stained by immunohistochemical methods for COX, and graded 0-3+. A score of 2-3+ was considered positive. Overall survival from original diagnosis for the entire cohort was 44% at 10 years. Survival rate after chest wall recurrence was 28% at 10 years. The distant metastasis-free survival rate after CWR was 40% at 10 years. Local-regional control of disease was achieved in 79% at 10 years after CWR. COX was considered positive in 13 of 38 cases. COX was inversely correlated with ER (p= .045) and PR (p = .028), and positively correlated with HER-2/neu (p =.003). COX was also associated with a shorter time to PMCWR. The distant metastasis-free rate for COX negative patients was 70% at 10 years, compared with 31% at 10 years for COX-2 positive patients (p = 0.029). COX positive had a poorer local-regional progression-free rate of 19% at 10 years, compared with 81% at 10 years for COX negative (p = 0.003). Outcome following RT for PMCWR is relatively poor. Positive COX correlated with other markers of poor outcome including a shorter time to local relapse, negative ER/PR and positive Her-2/neu status. Positive COX correlated with higher distant metastasis and lower local-regional control of disease. If confirmed with larger studies, these data have implications with respect to the concurrent use of COX-2 inhibitors and radiation for PMCWR

Parameters influencing Magnolia grandiflora L. seed germination

The seeds of Magnolia grandiflora are diverse in weight, size and density; therefore this study was undertaken to measure these physical parameters and to determine their relationship to germination. Additional parameters of paired seed, non-paired seed, seed location within the aggregate, bloom period and harvest periods were also studied to determine their relationship to germination. The blossoms of the Magnolia grandiflora trees were tagged each week and then harvested when matured. After seed collection the seeds were cleaned, weighed and their densities estimated by floatation. The seeds were planted and stratified for ninety days. After stratification was complete, a forty-five day germination test was conducted. Data were analyzed using an analysis of variance for germination percent and it was determined there were no significant differences between trees, between weight groups, between seed locations on the aggregate or between paired and non-paired seed. The density classes of .91 g/ml and 1.0 g/ml had significantly higher germination percentages than the .78 g/ml and \u3c.78 g/ml density classes. The later harvest period, November 21, 1985 resulted in larger germination percentages. Peak blossom was also determined and occurred near June 20, 1985

Masking Your Rights: Facemask Requirements Under Mandatory Influenza-Vaccination Policies Violate Privacy Rights of Health Care Workers

Hospitals should abandon the facemask requirements in their mandatory influenza-vaccination programs because the facemasks can infringe on the privacy rights of health care workers, and hospitals can still achieve their vaccination goals through less restrictive practices. Part II introduces the recent rise of mandatory influenza-vaccination policies for health care workers, how hospitals exempt certain employees, and the consequences for those exempted. Part III discusses the legal implications of requiring exempted employees to wear facemasks and other identifying material under federal and state privacy law. Part IV recommends that health care employers abandon facemask requirements in their mandatory-vaccination programs in order to avoid privacy violations. Part V concludes

Slow Life Strategists Hold More Growth Mindsets (for Intelligence not Physical Attractiveness)

HonorsPsychologyUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/169429/1/janetykk.pd

Famines in Africa: is early warning early enough?

Following the second Sahelian famine in 1984–1985, major investments were made to establish Early Warning Systems. These systems help to ensure that timely warnings and vulnerability information are available to decision makers to anticipate and avert food crises. In the recent crisis in the Horn of Africa, alarming levels of acute malnutrition were documented from March 2010, and by August 2010, an impending food crisis was forecast. Despite these measures, the situation remained unrecognised, and further deteriorated causing malnutrition levels to grow in severity and scope. By the time the United Nations officially declared famine on 20 July 2011, and the humanitarian community sluggishly went into response mode, levels of malnutrition and mortality exceeded catastrophic levels. At this time, an estimated 11 million people were in desperate and immediate need for food. With warnings of food crises in the Sahel, South Sudan, and forecast of the drought returning to the Horn, there is an immediate need to institutionalize change in the health response during humanitarian emergencies. Early warning systems are only effective if they trigger an early response