Bone Strength and Distal Femur Trabecular Thickness in Sleep Deprived Ovariectomized Rats Treated with Zoledronate

Osteoporosis is a disease that causes the density and quality of bone to be decreased, which can increase the risk of fracture by 40%. 1 in 3 women over the age of 50 will be affected by osteoporosis. This study aimed to show how bone strength and distal femur trabecular thickness might be affected by Zoledronate and sleep-deprivation in estrogen-deficient rats. Wistar female rats were ovariectomized to contrive postmenopausal estrogen-deficiency. The rats were separated into 4 groups. The control group (C, n=4) was given an intraperitoneal (IP) injection of 0.45 mL of 0.9% saline, were housed in standard conditions permitting 12 hours light and 12 hours dark. The Zoledronate (Z, n=8) were given an IP injection of 50ug/kg of 10% Zoledronate and housed in standard conditions with a 12 hour light/dark cycle. The sleep-deprived group (SD, n=8) were given the same IP injection as the rats in C but were housed in chambers that did not permit sleep for 18 hours, then moved to sleep chambers for 6 hours. The sleep-deprived Zoledronate group (SDZ, n=8) experienced the same sleep deprivation as the SD group but received an IP injection of 50ug/kg body weight of 10% Zoledronate. After 5 weeks, tibiae and femora were harvested, wrapped in saline-soaked gauze and stored at -80F until a 3-point bending test, high-resolution micro-CT and peripheral computed tomography was done. The SD group showed reduced bone strength compared to the SDZ group (162.21N and 165.97N, respectively; N.S). The SDZ group also showed improved distal femur trabecular thickness compared to the SD group (75.5 microns and 68.375 microns, respectively; p\u3c0.05). The value of bisphosphonates is well documented. We attempted to illuminate the value of bisphosphonates in sleep-deprived environments in the hopes of evaluating the efficacy and potential therapy for executive women who consistently work in sleep-deprived states. Our findings are equivocal but encouraging to pursue studies of longer duration

Making Some Bones About It

The article discusses the importance of bone tissue to human beings and the ways to help students to understand its functions. The bone tissue forms the human skeleton to produce varied motions such as walking and talking. In addition, it protects the vital organs of a person and contributes the development of blood. The bone is composed of bone matrix, a dense material occupied by calcium and potassium salts. The matrix comprises several cell types including osteoblasts, osteocytes and osteoclasts. According to the author, a continuous influx of new calcium is necessary because of the constant remodeling of bone tissue. He noted the essential of stomach acid to calcium carbonate to break down the calcium into the bloodstrea

The Physiological Interaction of Sleep Deprivation and Zoledronate on Distal Femur Trabecular Thickness of Ovariectomized Rats

Osteoporosis, a disease resulting in an increased risk of fracture due to compromised bone, affects 1 in 3 postmenopausal women. Discontinuities in the microarchitecture of bone, such as trabeculae, are seen in postmenopausal osteoporosis. This study aimed to evaluate how sleep deprivation affects the distal femur trabecular thickness of estrogen-deficient rats treated with Zoledronate. 29 ovariectomized Wistar female rats were separated into 4 groups. The control group (C) was housed in standard housing with a 12-hour light/dark cycle and was given an intravenous injection of 0.45 mL of 0.9% saline. The Zoledronate group (Z) were also housed in standard conditions but given an intravenous injection of 50 ug/kg of 10% Zoledronate. The Sleep Deprived group (SD) were given an intravenous saline injection, but were housed in chambers that did not permit sleep for 18 hours, then moved to standard chambers that permitted 6 hours of sleep daily. The Sleep-Deprived Zoledronate group (SDZ) was housed the same as the SD group, but was given an intravenous injection of Zoledronate. After 5 weeks, tibiae and femora were harvested and stored at -80°C until high-resolution micro-CT was done. SDZ had improved distal femur trabecular thickness compared to C (75.5 microns and 67 microns, respectively; p=0.0001). Multi-factor ANOVA revealed a significant interaction between Zoledronate and sleep deprivation (p=0.0078). More research is needed to determine how this interaction impacts executive women who often suffer from sleep deprivation and demanding professions

Scaled Particle Theory for Hard Sphere Pairs. I. Mathematical Structure

We develop an extension of the original Reiss-Frisch-Lebowitz scaled particle theory that can serve as a predictive method for the hard sphere pair correlation function g(r). The reversible cavity creation work is analyzed both for a single spherical cavity of arbitrary size, as well as for a pair of identical such spherical cavities with variable center-to-center separation. These quantities lead directly to prediction of g(r). Smooth connection conditions have been identified between the small-cavity situation where the work can be exactly and completely expressed in terms of g(r), and the large-cavity regime where macroscopic properties become relevant. Closure conditions emerge which produce a nonlinear integral equation that must be satisfied by the pair correlation function. This integral equation has a structure which straightforwardly generates a solution that is a power series in density. The results of this series replicate the exact second and third virial coefficients for the hard sphere system via the contact value of the pair correlation function. The predicted fourth virial coefficient is approximately 0.6 percent lower than the known exact value. Detailed numerical analysis of the nonlinear integral equation has been deferred to the sequel (following paper

Evaluation of Tumor Necrosis Factor Alpha In Sleep-Deprived Menopausal- Induced Rats and The Impact On Bone Health

Post-menopausal osteoporosis as a consequence of estrogen depletion is a growing concern for women in the United States. As more women take on executive positions and experience sleep deprivation, there is the potential for up regulation of pro-inflammatory cytokines, such as tumor necrosis factor alpha. It follows that the homeostatic imbalance of osteoclastic and osteoblastic activity leads to a greater risk of disease. Bisphosphonates generally, and Zolendronate specifically works by decreasing the number of osteoclasts. This current study investigated the impact of Zolendronate on the concentrations of tumor necrosis factor alpha-type (TNFɑ) in 32 ovariectomized Wistar rats. Throughout a five week period of sleep deprivation cycles, the concentrations of TNFɑ were collected and examined. It was originally hypothesized that the sleep deprived group of rats would have the highest concentration of TNFɑ due to the biological stress associated with insomnia. However, TNFɑ levels were significantly higher in the Zolendronate group than both the control and sleep deprived groups, as well as the sleep deprived with Zolendronate groups (p\u3c0.01). We ascribe this to bisphosphonate induced transient fever seen in Zolendronate usage in previous studies (Zicuonzo, 2003). It is also suspected that the low concentrations of TNFɑ in the sleep deprived groups are seen due to the short time frame of this experiment along with a challenged immune system in the animals. With a longer period of sleep deprivation, it is possible that the hypothesized cytokine levels would be reached

Viscosity in spherically symmetric accretion

The influence of viscosity on the flow behaviour in spherically symmetric accretion, has been studied here. The governing equation chosen has been the Navier-Stokes equation. It has been found that at least for the transonic solution, viscosity acts as a mechanism that detracts from the effectiveness of gravity. This has been conjectured to set up a limiting scale of length for gravity to bring about accretion, and the physical interpretation of such a length-scale has been compared with the conventional understanding of the so-called "accretion radius" for spherically symmetric accretion. For a perturbative presence of viscosity, it has also been pointed out that the critical points for inflows and outflows are not identical, which is a consequence of the fact that under the Navier-Stokes prescription, there is a breakdown of the invariance of the stationary inflow and outflow solutions -- an invariance that holds good under inviscid conditions. For inflows, the critical point gets shifted deeper within the gravitational potential well. Finally, a linear stability analysis of the stationary inflow solutions, under the influence of a perturbation that is in the nature of a standing wave, has indicated that the presence of viscosity induces greater stability in the system, than has been seen for the case of inviscid spherically symmetric inflows.Comment: 7 pages. Minor changes made in the version published in MNRA

The Effect of Chronic Sleep Deprivation on Tumor Necrosis Factor Alpha and Bone Health in Peri-Menopausal Rats

Post-menopausal osteoporosis is a common syndrome in the United States. The cessation of estrogen signaling coupled with the production of pro-inflammatory cytokines from sleep deprivation leads to an even greater risk of post-menopausal osteoporosis by creating an imbalance between osteoblasts and osteoclasts. With estrogen no longer present to regulate the concentration of osteoclasts and pro-inflammatory cytokines increasing production of osteoclasts, bone is degraded at a faster rate than it is formed. One of the most common treatments for osteoporosis is Zolendronate (a nitrogenous bisphosphonate), which decreases the number of osteoclasts in bone. This preliminary study looked at the effects on the concentration of tumor necrosis factor alpha-type (TNFα), a pro-inflammatory cytokine, and bone strength due to Zolendronate and sleep deprivation in thirty-two ovariectomized Wistar rats. After a five-week sleep deprivation protocol, TNFα concentrations were determined by enzyme-linked immunoassay and bone strengths were determined by a three point bending test. There were no significant differences in bone strength, and the only significant difference in serum concentrations of TNFα (P\u3c.01) was with the group that received Zolendronate. While we expected that the sleep deprived and sleep deprived with Zolendronate groups would have significantly higher TNFα concentrations we purpose an over-exhausted immune system is responsible our low concentrations. The reason the Zolendronate group had a significantly higher TNFα level could have been due to a transient fever caused by the drug. Further research measuring the changes in cytokine concentration throughout a longer sleep deprivation protocol needs to be done