46 research outputs found
Sex-related variation in compact bone microstructure of the femoral diaphysis in juvenile rabbits
<p>Abstract</p> <p>Background</p> <p>While gross morphological changes in the skeleton between males and females are well know, differences between sexes in the histomorphology are less known. It is important to have knowledge on the bone structure of rabbits, as this is a widely used species in biomedical research. A study was performed to evaluate the association between sex and the compact bone morphology of the femoral diaphysis in juvenile rabbits.</p> <p>Methods</p> <p>Seventeen clinically healthy 2–3 month-old rabbits (9 females, 8 males) were included in the study. The rabbits were euthanized and the right femur was sampled for analysis. 70–80 microns thick bone sections of the femoral diaphysis were prepared using standard histological equipment. The qualitative histological characteristics were determined according to internationally accepted classification systems while the quantitative parameters were assessed using the software Scion Image. Areas, perimeters, minimum and maximum diameters of primary osteons' vascular canals, Haversian canals and secondary osteons were measured. Additionally, blood plasma concentrations of progesterone, corticosterone, IGF-I, testosterone and estradiol were analyzed.</p> <p>Results</p> <p>Qualitative histological characteristics were similar for both sexes. However, variations of certain quantitative histological characteristics were identified. Measured parameters of the primary osteons' vascular canals were higher in males than for females. On the other hand, females had significant higher values of secondary osteons parameters. Differences in Haversian canals parameters were only significant for minimum diameter.</p> <p>Conclusion</p> <p>The study demonstrated that quantitative histological characteristics of compact bone tissue of the femoral diaphysis in juvenile rabbits were sex dependent. The variations may be associated with different growth and modeling of the femur through influence by sex-specific steroids, mechanical loads, genetic factors and a multitude of other sources. The results can be applied in experimental studies focusing on comparison of the skeletal biology of the sexes.</p
Proteases of haematophagous arthropod vectors are involved in blood-feeding, yolk formation and immunity : a review
Ticks, triatomines, mosquitoes and sand flies comprise a large number of haematophagous arthropods considered vectors of human infectious diseases. While consuming blood to obtain the nutrients necessary to carry on life functions, these insects can transmit pathogenic microorganisms to the vertebrate host. Among the molecules related to the blood-feeding habit, proteases play an essential role. In this review, we provide a panorama of proteases from arthropod vectors involved in haematophagy, in digestion, in egg development and in immunity. As these molecules act in central biological processes, proteases from haematophagous vectors of infectious diseases may influence vector competence to transmit pathogens to their prey, and thus could be valuable targets for vectorial control
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A 5-year randomized controlled, double-blind study of glycosaminoglycan polysulphuric acid complex (Rumalon®) as a structure modifying therapy in osteoarthritis of the hip and knee
Objective To determine the structure (disease) modifying effect of a glycosaminoglycan polypeptide association complex (GP-C; Rumalon®) in patients with knee and hip osteoarthritis (OA).
Methods Double-blind, randomized, placebo-controlled five-year study. Primary assessment criterion was change in radiographic joint space width between baseline and follow-up at 5 years. Secondary outcome criteria included Lequesne algofunctional index (LAI), pain on passive motion and consumption of non-steroidal antiinflammatory drugs (NSAIDs). The patients received 10 courses of injections of placebo or GP-C 2ml intramuscularly in 5 years (two courses each year). Each course included 15 injections administered twice weekly.
Results There were 277 patients with knee OA and 117 patients with hip OA. Control and GP-C treated groups were comparable as to sex, age, duration of disease, body weight, X-ray stage and value of LAI at the baseline. Knee joint space at 5 years decreased 0.37±0.08 (mean±standard deviation) mm for GP-C and 0.42±0.08mm for placebo groups (P=0.68). Hip joint space at 5 years decreased 0.21±0.08mm for GP-C and 0.22±0.08mm for placebo groups (P=0.53). In a subset of patients with hip OA, Kellgren–Lawrence≥2 and JSW≥1mm, there was a trend in favor of GPC for lower joint space narrowing in 5 years (P=0.11). In addition, there were no statistical differences between the treatment groups in LAI, pain on passive motion and consumption of NSAIDs. Side-effects after GP-C (14.5%) were rare, mild and not more frequent than in the placebo group (15%).
Conclusion We were not able to demonstrate a structure modifying effect of GP-C in OA of the hip or knee. Radiographic progression of OA in both knee and hip OA was lower than expected in both study groups
Myrigalone A inhibits Lepidium sativum seed germination by interference with gibberellin metabolism and apoplastic superoxide production required for embryo extension growth and endosperm rupture
Myrica gale L. (sweet gale) fruit leachate contains myrigalone A (MyA), a rare C-methylated dihydrochalcone and putative allelochemical, which is known to be a phytotoxin impeding seedling growth. We found that MyA inhibited Lepidium sativum L. seed germination in a dose-dependent manner. MyA did not affect testa rupture, but inhibited endosperm rupture and the transition to subsequent seedling growth. MyA inhibited micropylar endosperm cap (CAP) weakening and the increase in the growth potential of the radical/hypocotyl region (RAD) of the embryo, both being key processes required for endosperm rupture. We compared the contents of abscisic acid (ABA) and gibberellins in the tissues and found that the major bioactive forms of gibberellin in L. sativum seed tissues were GA4 and GA6, while GA8 and GA13 were abundant inactive metabolites. MyA did not appreciably affect the ABA contents, but severely interfered with gibberellin metabolism and signaling by inhibiting important steps catalyzed by GA3 oxidase, as well as by interfering with the GID1-type gibberellin signaling pathway. The hormonally and developmentally regulated formation of apoplastic superoxide radicals is important for embryo growth. Specific zones within the RAD were associated with accumulation of apoplastic superoxide radicals and endoreduplication indicative of embryo cell extension. MyA negatively affected both of these processes and acted as a scavenger of apoplastic reactive oxygen species. We propose that MyA is an allelochemical with a novel mode of action on seed germination