Disease relevance of Haversian System

• Cross-sectional osteon size was measured in undecalcified stained sections of iliac crest bone specimens from normal individuals (n = 68) and from patients with spinal osteoporosis (n = 27), primary hyperparathyroidism (n = 23), epilepsia (receiving chronic anti-convulsant therapy) (n = 11), acromegaly (n = 18), and hypothyroidism (n = 12) [1].

High impact information on Haversian System

• In addition, thyroxine under these conditions resulted in an increase in the osteoid seam circumference, radial closure rate, and bone formation rate at the tissue level but decreased the osteon formation time [2].
• Because NO is inhibitory to osteoclastic resorption, it has been suggested that osteocytes expressing eNOS act as sentinels, confining resorption within single osteons [3].
• Estrogen withdrawal increased the proportion of Haversian canals with an eroded surface (106%, p = 0.047), a double label (238%, p = 0.004), osteoid (71%, p = 0.002), and alkaline phosphatase (ALP) 116%, p = 0.043) but not those showing tartrate-resistant acid phosphatase (TRAP) activity (p = 0.25) or a single label (p = 0.30) [4].
• These results indicate that both GH and high-dose IGF-I activate remodeling osteons [5].
• Decorin was prominent in the perilacunar matrix, the canaliculi of osteocytes, and the matrix immediately adjacent to quiescent Haversian canals [6].

Biological context of Haversian System

• The hypothesis that incomplete resorption of osteons in an autogenous cortical bone graft may limit its replacement by new bone regeneration was explored by implanting a hydroxyapatite replica of a coral skeletal structure into bone gaps [7].

Anatomical context of Haversian System

• After drying and mounting in epoxy resin nanoindentation tests were conducted to measure Young's modulus and the hardness of individual trabeculae in the vertebrae and single osteons, and interstitial lamellae in the tibiae [8].
• We studied the correlation between differences in brightness and the related reflection coefficients of osteons on undecalcified transverse sections of goat tibial diaphysis using a 400-MHz burst mode lens on the Olympus UH3 SAM [9].
• This paper outlines the morphology of osteons and capillaries in cortical bone and discusses the possible morphological effects of systemic phenylephrine on mice tibiae [10].

Associations of Haversian System with chemical compounds

• OX increased the number of tetracycline-labeled osteons in cortical bone but reduced the percent trabecular surface labeled with tetracycline [11].
• Intracortical cavity number and area increased after 10 days of PGE2 treatment, but with forming osteon number and area far exceeding those of resorption cavities at day 30 [12].
• Using basic fuchsin-stained, undecalcified cross-sections from the dorsal, medial, and lateral midshaft regions of 12 pairs of cannon bones, we classified 360 secondary osteons according to their birefringence patterns, and measured their inner and outer diameters [13].
• The current study provides a quantitative analysis of the relationships between osteonal osteocyte density (Ot.N/BV), wall width (W.Wi), individual osteon porosity (IOP), and formation period (FP) in ulnar cortices from sheep labeled with tetracycline and calcein double labels [14].
• Calcium sulfate in slurry form does however improve the surgical handling of particulate bone graft substitutes such as Pro Osteon 200 R, which remained as an osteoconductive scaffold for up to 52 weeks and may have played an important role in the ultimate closure of the cortical windows [15].

Gene context of Haversian System

• PTH increased the radial closure rate and decreased the osteon formation time in unaltered cortical bone [16].
• Inflammatory cell changes in haversian canals. A possible cause of osteoporosis in rheumatoid arthritis [17].

Analytical, diagnostic and therapeutic context of Haversian System

• Analysis of the bone surrounding an uncemented titanium hip prosthesis highlights that both remodeled and newly formed bone have lamellae oriented parallel to prosthesis surfaces, i.e. orthogonal to loads, as opposed to that of lamellar bone of osteons which are oriented parallel to loads [18].
• We studied the correlations between TB color intensity and the differences in stiffness and degree of mineralization of individual osteons in undecalcified histological sections of goat tibial diaphysis, measured by scanning acoustic microscopy (SAM) and contact microradiography (CMR), respectively [19].

References