53 research outputs found
Antigenic Variation in Plasmodium falciparum Malaria Involves a Highly Structured Switching Pattern
Many pathogenic bacteria, fungi, and protozoa achieve chronic infection through
an immune evasion strategy known as antigenic variation. In the human malaria
parasite Plasmodium falciparum, this involves transcriptional
switching among members of the var gene family, causing
parasites with different antigenic and phenotypic characteristics to appear at
different times within a population. Here we use a genome-wide approach to
explore this process in vitro within a set of cloned parasite
populations. Our analyses reveal a non-random, highly structured switch pathway
where an initially dominant transcript switches via a set of
switch-intermediates either to a new dominant transcript, or back to the
original. We show that this specific pathway can arise through an evolutionary
conflict in which the pathogen has to optimise between safeguarding its limited
antigenic repertoire and remaining capable of establishing infections in
non-naïve individuals. Our results thus demonstrate a crucial role for
structured switching during the early phases of infections and provide a
unifying theory of antigenic variation in P. falciparum malaria
as a balanced process of parasite-intrinsic switching and immune-mediated
selection
No association between the aluminium content of trabecular bone and bone density, mass or size of the proximal femur in elderly men and women
BACKGROUND: Aluminium is considered a bone toxic metal since poisoning can lead to aluminium-induced bone disease in patients with chronic renal failure. Healthy subjects with normal renal function retain 4% of the aluminium consumed. They might thus also accumulate aluminium and eventually be at risk of long-term low-grade aluminium intoxication that can affect bone health. METHODS: We therefore examined 62 patients with femoral neck fractures or osteoarthritis of the hip (age range 38–93), with the aim of examining whether aluminium in bone is associated with bone-mineral density (BMD), content (BMC) or width of the femoral neck measured by dual-energy X-ray absorptiometry (DXA). During operations bone biopsies were taken from the trabecular bone of the proximal femur. The samples were measured for their content of aluminium using a mass spectrometer. RESULTS: No significant association between the aluminium content in bone and femoral neck BMD, BMC or width could be found after multivariate adjustment. CONCLUSION: Our results indicate that the accumulated aluminium content in bone during life does not substantially influence the extent of osteoporosis
Evidence-based guidelines for the pharmacological treatment of postmenopausal osteoporosis: a consensus document by the Belgian Bone Club
Several drugs are available for the management of postmenopausal osteoporosis. This may, in daily practice, confuse the clinician. This manuscript offers an evidence-based update of previous treatment guidelines, with a critical assessment of the currently available efficacy data on all new chemical entities which were granted a marketing authorization. Osteoporosis is widely recognized as a major public health concern. The availability of new therapeutic agents makes clinical decision-making in osteoporosis more complex. Nation-specific guidelines are needed to take into consideration the specificities of each and every health care environment. The present manuscript is the result of a National Consensus, based on a systematic review and a critical appraisal of the currently available literature. It offers an evidence-based update of previous treatment guidelines, with the aim of providing clinicians with an unbiased assessment of osteoporosis treatment effect
Minimally Invasive Treatment of Infection Staghorn Stones with Shock Wave Lithotripsy and Chemolysis
Alendronate Reduces Bone Toughness of Ribs without Significantly Increasing Microdamage Accumulation in Dogs Following 3 Years of Daily Treatment
Therapeutic equivalence of alendronate 70 mg once-weekly and alendronate 10 mg daily in the treatment of osteoporosis.
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