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Biomolecules and Tissue Properties
Published in Joseph W. Freeman, Debabrata Banerjee, Building Tissues, 2018
Joseph W. Freeman, Debabrata Banerjee
Collagen diseases arise from genetic defects that affect the biosynthesis, assembly, posttranslational modification, secretion, or other processes in the normal production of collagen. Osteogenesis imperfecta (OI) is a brittle bone disease. This results from decreased quantity or quality of collagen I in the bone. Osteogenesis imperfect occurs when changes in certain amino acids in the triple helix affect collagen structure and assembly. This effects the nucleation and laying down of hydroxyapatite. In general, type I is the mildest form of this disease, whereas types IV, III, and II indicate increasing severities of disease. Aside from Type I, the life expectancy of patients with all other forms of OI is often assumed to be shortened. However, life expectancy of patients with OI type IA is the same as that of the general population. In type IB, mortality is modestly increased compared with that of the general population. Type II OI is fatal in the perinatal period, shortly before and after birth. Type III affects life expectancy; however, patients with type III OI surviving beyond the age of 10 years have a better outlook than other patients with OI. For Type IV, mortality is modestly increased compared with that of the general population.6,7
Study of age-related changes in Middle ear transfer function
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2019
Lei Zhou, Na Shen, Miaolin Feng, Houguang Liu, Maoli Duan, Xinsheng Huang
There are numerous studies on otosclerosis (OS) and OP. Swinnen et al. found that patients with osteogenesis imperfecta are at risk of hearing loss (Swinnen et al. 2012). Clark et al. studied the relationship between hearing loss and bone mass in 369 females drawn from a population of rural women aged 60–85 years, and found that a consistent association between femoral neck bone mass and age-related hearing loss (Clark et al. 1995). Atan et al. investigated OS and OP using a bone mineral density test in postmenopausal women, and noted a tendency for OP in patients with OS (Atan et al. 2016). Clayton et al. reported a positive association between OS and OP in 200 women aged 50–75 years (Clayton et al. 2004). Mckenna et al. found that some cases of OS and OP shared a functionally significant polymorphism in the Sp1 transcription factor binding site in the first intron of the COL1A1 gene (Mckenna et al. 2004). Quesnel et al. used an anti OP drug to treat sensorineural hearing loss (SNHL) related to OS, and achieved stabilization in their treatment groups (Quesnel et al. 2012). These studies demonstrate a correlation between OP and OS, a common cause of conductive hearing loss; these two diseases are both metabolic bone abnormality. It is possible that ossicles may also undergo metabolic abnormalities, such as OP, in common with other bones. Furthermore, the soft tissue in the middle ear may develop age-related changes.
Effects of whole body vibration on bone properties in growing rats
Published in International Biomechanics, 2022
A number of animal studies have examined the effects of WBV on bone properties in normal young rodents (Xie et al. 2006, 2008; Gnyubkin et al. 2016; Zhang et al. 2018). These studies have reported that WBV improves bone mass and structural parameters in young rodents with spinal cord injury, unloading, ovariectomy or osteogenesis imperfecta (Li et al. 2012; Vanleene and Shefelbine 2013; Chen et al. 2014; Minematsu et al. 2016). For instance, in young normal male mice, WBV for 3 weeks increased femoral cortical thickness and cross-sectional area, and when applied for 9 weeks, WBV increased femoral cortical tissue mineral density (TMD) (Gnyubkin et al. 2016). WBV also decreased osteoclastic activity in tibial trabecular bone and increased the bone formation rate of the tibial metaphysis when applied for 3 weeks in young normal female mice (Xie et al. 2006). Moreover, WBV for 5 weeks increased femoral mechanical strength in growing female mice (Vanleene and Shefelbine 2013). As mentioned above, most studies reporting the positive effects of WBV on bone properties in young rodents used frequencies in the range of 30–90 Hz with 0.3 g acceleration for 15–20 min/day, 5 days/week (Xie et al. 2006, 2008; Vanleene and Shefelbine 2013; Gnyubkin et al. 2016). Cumulative doses of WBV stimulation ranged from 75 to 100 min/week with a duration of over 225 minutes during the intervention period. In contrast, WBV had no effects on femoral bone mass, structure or mechanical strength when applied for 12 weeks in growing normal female rats (Zhang et al. 2018). Thus, there are inconsistencies in the field regarding the impact of WBV and its effectiveness as a preventive measure against osteoporosis. Sensitivity of bone to WBV likely differs depending on the particular conditions used, including differences in parameters such as frequency, acceleration, duration, term and timing of intervention, as well as the age of rodents, and it is unclear whether WBV has beneficial effects on bone properties of growing rats. A number of animal studies have examined the effects of WBV on bone using low-magnitude, high frequency vibration stimuli, especially in non-invasive growing rodents (Xie et al. 2006; Gnyubkin et al. 2016; Zhang et al. 2018). Mechanical stimuli under these conditions were effective in eliciting a bone response (Rubin et al. 2001). In addition, our previous study (Minematsu et al. 2019) showed that WBV at 45–60 Hz frequency with 0.5 g acceleration had a potential to improve bone properties in growing rats. Therefore, the present study used vibration stimuli at 50 Hz and 0.5 g. Rats are widely used in bone studies. We used growing rats aged 5 weeks because rat bone grows rapidly for 10 weeks after birth and slowly thereafter, and BMD similarly increases rapidly after birth (Horton et al. 2008). In addition, few studies have examined WBV and bone properties using growing rats (i.e. younger than 5-week-old). Growing bone during and after the rapid growth phase is sensitive and responsive to WBV. This study aimed to examine the effects of WBV for 5 and 10 weeks on tibial bone properties in growing rats aged 5 weeks.