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 microl 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.
OBJECTIVES: To evaluate and compare the depth and distances from various points of the orbital rim to the fissures and foramina of the orbital apex between genders in the local population.
METHODOLOGY: Linear measurements were conducted on 60 orbits from 30 patients who had undergone head computed tomography scan. These measurements were done utilizing the multiplanar reconstruction modes on computed tomography images with minimum slice thickness of 1 mm.
RESULTS: Males have statistically significant larger orbits than females with higher mean measurements in all parameters, except for the distance from posterior ethmoidal foramen to the optic canal which was the same. However, there were no significant differences in all parameters between the right and left orbits.
CONCLUSION: This study provides the absolute limit of safe internal orbital dissection in respect to the local population. Despite males having larger orbits than females, it is clinically negligible.
OBJECTIVES: The present study was designed to 1) validate the use of UBM for non-invasive monitoring of grafts/implants over-time, and to 2) correlate UBM findings with the morphological attributes of recovered grafts/implants.
MATERIALS AND METHODS: Testis tissue fragments (~14 mm3 , each) and cell aggregates (100×106 cells, each) obtained from 1-wk-old donor piglets (n = 30) were grafted/implanted under the back skin of immunodeficient mice (n = 6) in eight analogous sites per mouse. Three-dimensional transcutaneous Doppler UBM was performed and a randomly-selected graft and its corresponding implant were recovered at 2, 4, 6, and 8 wk.
RESULTS: Graft/implant weight (p = 0.04) and physical height (p = 0.03) increased over-time. The dynamics of physical length and volume increases over time differed between tissue grafts and cell implants (p = 0.02 and 0.01 for sample type*time interactions, respectively). UBM-estimated volume was correlated with the post-recovery weight and volume of the grafts/implants (r = 0.98 and r = 0.99, respectively; p < 0.001). Pre- and post-recovery length and height of the grafts/implants were positively and strongly correlated (r = 0.50, p = 0.01; r = 0.70, p = 0.001) and so were the areas covered by cordal, non-cordal or fluid-filled cavities between UBM and histology (r = 0.87, p < 0.001).
DISCUSSION AND CONCLUSION: UBM findings correlated with physical attributes of the grafts/implants, validating its use as a non-invasive high-fidelity tool to quantify the developmental changes in ectopic testis tissue grafts and cell implants, potentially leading to a reduction in the number of recipient mice needed for similar experiments.
METHODS: In a systematic study of the presentation and course of patients with acute P. knowlesi infection, clinical and laboratory data were collected from previously untreated, nonpregnant adults admitted to the hospital with polymerase chain reaction-confirmed acute malaria at Kapit Hospital (Sarawak, Malaysia) from July 2006 through February 2008.
RESULTS: Of 152 patients recruited, 107 (70%) had P. knowlesi infection, 24 (16%) had Plasmodium falciparum infection, and 21 (14%) had Plasmodium vivax. Patients with P. knowlesi infection presented with a nonspecific febrile illness, had a baseline median parasitemia value at hospital admission of 1387 parasites/microL (interquartile range, 6-222,570 parasites/microL), and all were thrombocytopenic at hospital admission or on the following day. Most (93.5%) of the patients with P. knowlesi infection had uncomplicated malaria that responded to chloroquine and primaquine treatment. Based on World Health Organization criteria for falciparum malaria, 7 patients with P. knowlesi infection (6.5%) had severe infections at hospital admission. The most frequent complication was respiratory distress, which was present at hospital admission in 4 patients and developed after admission in an additional 3 patients. P. knowlesi parasitemia at hospital admission was an independent determinant of respiratory distress, as were serum creatinine level, serum bilirubin, and platelet count at admission (p < .002 for each). Two patients with knowlesi malaria died, representing a case fatality rate of 1.8% (95% confidence interval, 0.2%-6.6%).
CONCLUSIONS: Knowlesi malaria causes a wide spectrum of disease. Most cases are uncomplicated and respond promptly to treatment, but approximately 1 in 10 patients develop potentially fatal complications.