Bone Growth Rate Research Articles

Strontium exerts dual effects on calcium phosphate cement: Accelerating the degradation and enhancing the osteoconductivity both in vitro and in vivo.

Calcium phosphate cements (CPCs) have long been used as osteoconductive bone substitutes in the treatment of bone defects. However, the degradation rate of CPC is typically too slow to match the new bone growth rate. It is known that strontium increases the solubility of hydroxyapatite as well as exerts both anabolic and anticatabolic effects on bone. Therefore, we hypothesized that the incorporation of strontium would accelerate the degradation rate and enhance the osteoconductivity of CPC. In this study, Three groups, CPC (0% Sr-CPC), 5% Sr-CPC, and 10% Sr-CPC, were prepared, with the total molar ratio for Sr/(Sr+Ca) in the cement powder phase being 0, 5, and 10%, respectively. In the immersion test, less residual weight was observed in both 5% Sr-CPC and 10% Sr-CPC groups than CPC group. In addition, a higher osteoblastic cell proliferation rate and alkaline phosphatase activity were obtained in the strontium groups. In a rat femur bone defect model comparing CPC with 10% Sr-CPC, at 2 weeks postoperation, early endochondral ossification was found in the 10% Sr-CPC group, whereas only fibrous tissue was observed in control group; at 4-16 weeks postoperation, progressive osteoconduction toward the cement was observed in both groups. At 32 weeks, a higher peri-cement bone area and reduced cement area were noted in the 10% Sr-CPC group. In conclusion, in the 10% Sr-CPC group, strontium exerts dual effects on CPC: accelerating degradation rate and enhancing osteoconductivity, as shown here both in vitro and in vivo.

Two developmentally temporal quantitative trait loci underlie convergent evolution of increased branchial bone length in sticklebacks

In convergent evolution, similar phenotypes evolve repeatedly in independent populations, often reflecting adaptation to similar environments. Understanding whether convergent evolution proceeds via similar or different genetic and developmental mechanisms offers insight towards the repeatability and predictability of evolution. Oceanic populations of threespine stickleback fish, Gasterosteus aculeatus, have repeatedly colonized countless freshwater lakes and streams, where new diets lead to morphological adaptations related to feeding. Here, we show that heritable increases in branchial bone length have convergently evolved in two independently derived freshwater stickleback populations. In both populations, an increased bone growth rate in juveniles underlies the convergent adult phenotype, and one population also has a longer cartilage template. Using F2 crosses from these two freshwater populations, we show that two quantitative trait loci (QTL) control branchial bone length at distinct points in development. In both populations, a QTL on chromosome 21 controls bone length throughout juvenile development, and a QTL on chromosome 4 controls bone length only in adults. In addition to these similar developmental profiles, these QTL show similar chromosomal locations in both populations. Our results suggest that sticklebacks have convergently evolved longer branchial bones using similar genetic and developmental programmes in two independently derived populations.

Life-history traits of the Miocene Hipparion concudense (Spain) inferred from bone histological structure.

Histological analyses of fossil bones have provided clues on the growth patterns and life history traits of several extinct vertebrates that would be unavailable for classical morphological studies. We analyzed the bone histology of Hipparion to infer features of its life history traits and growth pattern. Microscope analysis of thin sections of a large sample of humeri, femora, tibiae and metapodials of Hipparion concudense from the upper Miocene site of Los Valles de Fuentidueña (Segovia, Spain) has shown that the number of growth marks is similar among the different limb bones, suggesting that equivalent skeletochronological inferences for this Hipparion population might be achieved by means of any of the elements studied. Considering their abundance, we conducted a skeletechronological study based on the large sample of third metapodials from Los Valles de Fuentidueña together with another large sample from the Upper Miocene locality of Concud (Teruel, Spain). The data obtained enabled us to distinguish four age groups in both samples and to determine that Hipparion concudense tended to reach skeletal maturity during its third year of life. Integration of bone microstructure and skeletochronological data allowed us to identify ontogenetic changes in bone structure and growth rate and to distinguish three histologic ontogenetic stages corresponding to immature, subadult and adult individuals. Data on secondary osteon density revealed an increase in bone remodeling throughout the ontogenetic stages and a lesser degree thereof in the Concud population, which indicates different biomechanical stresses in the two populations, likely due to environmental differences. Several individuals showed atypical growth patterns in the Concud sample, which may also reflect environmental differences between the two localities. Finally, classification of the specimens’ age within groups enabled us to characterize the age structure of both samples, which is typical of attritional assemblages.

Effects of Eucommia ulmoides extract on longitudinal bone growth rate in adolescent female rats.

Eucommia ulmoides is one of the popular tonic herbs for the treatment of low back pain and bone fracture and is used in Korean medicine to reinforce muscles and bones. This study was performed to investigate the effects of E. ulmoides extract on longitudinal bone growth rate, growth plate height, and the expressions of bone morphogenetic protein 2 (BMP-2) and insulin-like growth factor 1 (IGF-1) in adolescent female rats. In two groups, we administered a twice-daily dosage of E. ulmoides extract (at 30 and 100 mg/kg, respectively) per os over 4 days, and in a control group, we administered vehicle only under the same conditions. Longitudinal bone growth rate in newly synthesized bone was observed using tetracycline labeling. Chondrocyte proliferation in the growth plate was observed using cresyl violet dye. In addition, we analyzed the expressions of BMP-2 and IGF-1 using immunohistochemistry. Eucommia ulmoides extract significantly increased longitudinal bone growth rate and growth plate height in adolescent female rats. In the immunohistochemical study, E. ulmoides markedly increased BMP-2 and IGF-1 expressions in the proliferative and hypertrophic zones. In conclusion, E. ulmoides increased longitudinal bone growth rate by promoting chondrogenesis in the growth plate and the levels of BMP-2 and IGF-1. Eucommia ulmoides could be helpful for increasing bone growth in children who have growth retardation.

Correlation of quantitative bone histology data with life history and climate: a phylogenetic approach

Growth rate is a fitness component that is determined by intrinsic (e.g. metabolism) and extrinsic (environment) factors, the relative importance of which remains to be ascertained. Vascular and cellular networks of primary compact bone tissue correlate with bone growth rate in vertebrates. Here, we aim to determine the main factor, either intrinsic or extrinsic, that shapes the vascular and cellular networks of fibrolamellar bone tissue. To do this, we examine the correlation of some life-history traits in bovids, such as body mass at birth, adult body mass and relative age at reproductive maturity (relative to body mass) as a proxy of the species' pace of life, and climatic regimes, with quantitative data from bone histology in a phylogenetic context. We quantify vascular orientation and vascular and cell densities in 51 wild ruminants with known environmental conditions belonging to 26 species of bovids and one chevrotain. Our results show that the quantified histological variables do not correlate with broad climatic categories or with life history. Instead, they are related to body mass: larger bovids display more circular canals and lower cell densities than smaller bovids. We suggest the former is related to higher rates of periosteal bone deposition, whereas the latter is related to lower mass-specific metabolic rates. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 112, 678–687.

Effects of Calcium Phosphate/Chitosan Composite on Bone Healing in Rats: Calcium Phosphate Induces Osteon Formation

Vascularization of an artificial graft represents one of the most significant challenges facing the field of bone tissue engineering. Over the past decade, strategies to vascularize artificial scaffolds have been intensively evaluated using osteoinductive calcium phosphate (CaP) biomaterials in animal models. In this work, we observed that CaP-based biomaterials implanted into rat calvarial defects showed remarkably accelerated formation and mineralization of new woven bone in defects in the initial stages, at a rate of ∼60 μm/day (0.8 mg/day), which was considerably higher than normal bone growth rates (several μm/day, 0.1 mg/day) in implant-free controls of the same age. Surprisingly, we also observed histological evidence of primary osteon formation, indicated by blood vessels in early-region fibrous tissue, which was encapsulated by lamellar osteocyte structures. These were later fully replaced by compact bone, indicating complete regeneration of calvarial bone. Thus, the CaP biomaterial used here is not only osteoinductive, but vasculogenic, and it may have contributed to the bone regeneration, despite an absence of osteons in normal rat calvaria. Further investigation will involve how this strategy can regulate formation of vascularized cortical bone such as by control of degradation rate, and use of models of long, dense bones, to more closely approximate repair of human cortical bone.

Seven Day Insertion Rest in Whole Body Vibration Improves Multi-Level Bone Quality in Tail Suspension Rats

ObjectiveThis study aimed to investigate the effects of low-magnitude, high-frequency vibration with rest days on bone quality at multiple levels.MethodsForty-nine three-month-old male Wistar rats were randomly divided into seven groups, namely, vibrational loading for X day followed by X day rest (VLXR, X = 1, 3, 5, 7), vibrational loading every day (VLNR), tail suspension (SPD), and baseline control (BCL). One week after tail suspension, rats were loaded by vibrational loading (35 Hz, 0.25 g, 15 min/day) except SPD and BCL. Fluorescence markers were used in all rats. Eight weeks later, femora were harvested to investigate macromechanical properties, and micro-computed tomography scanning and fluorescence test were used to evaluate microarchitecture and bone growth rate. Atomic force microscopy analyses and nanoindentation test were used to analyze the nanostructure and mechanical properties of bone material, respectively. Inductively coupled plasma optical emission spectroscopy was used for quantitative chemical analyses.ResultsMicroarchitecture, mineral apposition rate and bone formation rate and macromechanical properties were improved in VL7R. Grain size and roughness were significantly different among all groups. No statistical difference was found for the mechanical properties of the bone material, and the chemical composition of all groups was almost similar.ConclusionsLow-magnitude, high-frequency vibration with rest days altered bone microarchitecture and macro-biomechanical properties, and VL7R was more efficacious in improving bone loss caused by mechanical disuse, which provided theoretical basis and explored the mechanisms of vibration for improving bone quality in clinics.

Comparison of bone regeneration rate in flat and long bone defects: Calvarial and tibial bone

An ideal scaffold for bone tissue regeneration should be dissolved at the same rate of host bone growth into the defect. Therefore, to produce such a scaffold, it is necessary to obtain a standard healing rate of bone defects. In this study, we compared healing rate of bone defects in calvarial and long bones, which have differential developmental and regenerative mechanisms. In the calvaria and tibia, 3 mm defects were made, and healing was analyzed using microcomputed tomography (microCT) and histology up to six weeks. MicroCT analysis showed that in calvarial defects, an unhealed gap remained until six weeks, whereas tibial defects had healed after three weeks. H&E and Trichrome staining consistently showed that calvarial defects were not completely healed by six weeks, however, a tibial defect started to heal from three weeks. Results of histomorphometric analysis showed that 60% of calvarial defects had healed at six weeks after surgery, whereas 80% of tibial defects showed regeneration at three weeks. Cartilage formation was detected only in tibial defects, suggesting endochondral regeneration in long bone, but not in flat bone. Collectively, these results demonstrate that healing of a long bone defect is faster than that of flat bone by approximately two folds. Therefore, our data suggest that dissolution of scaffold should be optimized based on the type of bone defect.

Evidence for high bone growth rate in Euparkeria obtained using a new paleohistological inference model for the humerus

ABSTRACT The study of bone growth rate and metabolic rate evolution in archosaurs (crocodiles, dinosaurs including birds, and pterosaurs) and close outgroups has become a subject of major interest among paleontologists in recent years. In this paper, we estimate the bone growth rate of Euparkeria using a new statistical inference model for the humerus. We modified the taxonomic range of extant species used in previous studies, on which we performed quantitative measurements of histological features and bone growth rates. Bone growth rate values estimated for Euparkeria are crucial in understanding the ancestral condition for archosaurs because this taxon is considered the closest relative to the archosaur crown group. We obtained an instantaneous growth rate of 6.12 μm/day, suggesting that Euparkeria shared with other non-archosaurian archosauromorphs (Prolacerta, Proterosuchus, and Erythrosuchus) a condition of high growth rate compatible with endothermy. This derived state may have been inherited by some Triassic crurotarsans, as suggested by the high instantaneous bone growth rate (14.52 μm/day) estimated in this study for Postosuchus. Jurassic crurotarsans may have lost endothermy during the transition from terrestrial habitats and active predation to aquatic habitats and sit-and-wait predation behaviors, so that Cretaceous crocodiles may be secondarily ectothermic, as suggested by δ18O values. In conclusion, we provide new evidence for the hypothesis of an ancestral endothermic state for the last common ancestor of archosaurs, and show that non-archosaurian archosauromorphs and Triassic crurotarsans may have been characterized by a thermometabolism more similar to that of dinosaurs than to that of lepidosaurs and turtles.

Local Failure in Parameningeal Rhabdomyosarcoma: Does Response to Induction Chemotherapy Matter?

year EFS for localized and metastatic patients are 81% and 29% (p 8 cm), 95% vs 77%. General toxicities are shown in the table. In 31 patients with head and neck disease sites the CI of cataract is 35% at 5 years and is highly correlated with orbital disease site (100% vs 21%, p < 0.01) and dose to the lens (p < 0.01). Tumor size at diagnosis correlates with reduced mandibular ROM (p Z 0.04), while site does not (fav/unfav, p Z 0.15). In 14 patients with extremity disease sites, the CI of fracture is 17%, with an average max dose to bone of 46.8 Gy for all 14 patients. In a proportional hazard model, increasing age correlates with physis closure (p Z 0.01), while mean physis dose approaches, but is not significant (p Z 0.13). Growth rate of the bone is reduced by increasing age at RT (p < 0.01), while the impact of mean physis dose approaches significance (p Z 0.10). In 14 patients with pelvic disease 5/14 experienced at least one episode of 3+ hematuria within the first year of RT. Nine of 14 had a measurable degree of hematuria during that year. Ten of 14 had some degree of bladder wall thickening post RT on imaging. No patient required permanent urinary diversion. Conclusions: Modern 3DCRT/IMRT with specific targeting guidelines yields excellent local control for most children with RMS. Despite the use of modern RT and limited target volumes, measurable toxicities are evident and can be correlated with age and RT dose. Techniques and targeting paradigms that further reduce normal tissue exposures are needed. Author Disclosure: M. Krasin: E. Research Grant; Lance Armstrong Foundation Survivorship Grant 2005-2007. C. Hua: None. L.E. Kun: None. A. Pappo: None. A. Pai Panandiker: None. M. Brown: None. A. Davidoff: None. B. Shulkin: None. B. McCarville: None. T.E. Merchant: None.

Measurement, variation, and scaling of osteocyte lacunae: a case study in birds

Basic issues surrounding osteocyte biology are still poorly understood, including the variability of osteocyte morphology within and among bones, individuals, and species. Several studies have suggested that the volume or shape of osteocytes (or their lacunae) is related to bone and/or organismal growth rate or metabolism, but the nature of this relationship, if any, is unclear. Furthermore, several studies have linked osteocyte lacuna volume with genome size or growth rate and suggested that osteocyte lacuna volume is unrelated to body size. Herein the scaling of osteocyte lacuna volume with body mass, growth and basal metabolic rates, genome size, and red blood cell size is examined using a broad sample of extant birds within a phylogenetic framework. Over 12,000 osteocyte lacuna axes were measured in a variety of bones from 34 avian and four non-avian dinosaur species. Osteocyte lacunae in parallel-fibered bone are scalene ellipsoids; their morphology and volume cannot be reliably estimated from any single thin section, and using a prolate ellipsoid model to estimate osteocyte lacuna volume results in a substantial (ca. 2–7 times) underestimate relative to true lacunar volume. Orthogonal thin sections reveal that in birds, even when only observing parallel-fibered, primary, cortical bone, intra-skeletal variation in osteocyte lacuna volume and shape is very high (volumes vary by a factor of 5.4 among different bones), whereas variation among homologous bones of the same species is low (1.2–44%; mean=12%). Ordinary and phylogenetically informed bivariate and multiple regressions demonstrate that in birds, osteocyte volume scales significantly but weakly with body mass and mass-specific basal metabolic rate and moderately with genome size, but not with erythrocyte size. Avian whole-body growth rate and osteocyte lacuna volume are weakly and inversely related. Finally, we present the first three-dimensionally calculated osteocyte volumes for several non-avian dinosaurs, which are much larger than previously reported values and smaller than those of large extant avians. Osteocyte volumes estimated from a single transverse section and assuming prolate morphology, as done in previous studies, are relative underestimates in theropod dinosaurs compared to sauropod dinosaurs, raising the possibility that no major change in osteocyte volumes (and genome size) occurred within Theropoda on the lineage leading to birds. Osteocyte volume is intertwined with several organismal attributes whose relative importance varies at a number of hierarchical levels.

Age and Gender Affect Epiphyseal Closure in White-tailed Deer

Abstract Timing of epiphyseal closure determines length of long bones and thus body size, but factors affecting epiphyseal closure in Odocoileus virginianus (White-tailed Deer) have not been conclusively quantified. We collected morphometric data and radiographic images of the distal humerus, proximal radius, distal radius, and metacarpus on approximately 0.5-, 1.5-, 2.5-, and 3.5-year-old optimally nourished captive deer. Age affected closure of distal radial and metacarpal epiphyseal plates (P < 0.001), with all individuals exhibiting epiphyseal closure by 3.5 years of age. Gender affected closure of the distal radial epiphyseal plates (P = 0.036), with females closing prior to males. Differential bone growth rate prior to epiphyseal closure may be one mechanism by which individual and cohort phenotypic effects are manifested in cervids.

Rethinking the nature of fibrolamellar bone: an integrative biological revision of sauropod plexiform bone formation

We present novel findings on sauropod bone histology that cast doubt on general palaeohistological concepts concerning the true nature of woven bone in primary cortical bone and its role in the rapid growth and giant body sizes of sauropod dinosaurs. By preparing and investigating longitudinal thin sections of sauropod long bones, of which transverse thin sections were published previously, we found that the amount of woven bone in the primary complex has been largely overestimated. Using comparative cellular and light-extinction characteristics in the two section planes, we revealed that the majority of the bony lamina consists of longitudinally organized primary bone, whereas woven bone is usually represented only by a layer a few cells thin in the laminae. Previous arguments on sauropod biology, which have been based on the overestimated amount, misinterpreted formation process and misjudged role of woven bone in the plexiform bone formation of sauropod dinosaurs, are thereby rejected. To explain the observed pattern in fossil bones, we review the most recent advances in bone biology concerning bone formation processes at the cellular and tissue levels. Differentiation between static and dynamic osteogenesis (SO and DO) and the revealed characteristics of SO- versus DO-derived bone tissues shed light on several questions raised by our palaeohistological results and permit identification of these bone tissues in fossils with high confidence. By presenting the methods generally used for investigating fossil bones, we show that the major cause of overestimation of the amount of woven bone in previous palaeohistological studies is the almost exclusive usage of transverse sections. In these sections, cells and crystallites of the longitudinally organized primary bone are cut transversely, thus cells appear rounded and crystallites remain dark under crossed plane polarizers, thereby giving the false impression of woven bone. In order to avoid further confusion in palaeohistological studies, we introduce new osteohistological terms as well as revise widely used but incorrect terminology. To infer the role of woven bone in the bone formation of fast-growing tetrapods, we review some aspects of the interrelationships between the vascularity of bone tissues, basal metabolic rate, body size and growth rate. By putting our findings into the context of osteogenesis, we provide a new model for the diametrical limb bone growth of sauropods and present new implications for the evolution of fast growth in vertebrates. Since biomechanical studies of bone tissues suggest that predominant collagen fibre orientation (CFO) is controlled by endogenous, functional and perhaps phylogenetic factors, the relationship between CFO and bone growth rate as defined by Amprino's rule, which has been the basis for the biological interpretation of several osteohistological features, must be revised. Our findings draw attention to the urgent need for revising widely accepted basic concepts of palaeohistological studies, and for a more integrative approach to bone formation, biomechanics and bone microstructural features of extant and extinct vertebrates to infer life history traits of long extinct, iconic animals like dinosaurs.

A Systematic Review of the Use of Growth Factors in Human Periodontal Regeneration

There is a large body of evidence using cells and animal models demonstrating the effectiveness of growth factors in periodontal regeneration. However, there appears to be minimal literature comparing the efficacy of growth factors in human periodontal regeneration compared to other techniques and procedures. Therefore, the aim of this study is to perform a systematic review of human studies using growth factors for periodontal regeneration and to compare the efficacy of these growth factors to other accepted techniques for periodontal regeneration. An electronic and manual search based on agreed search phrases between the primary investigator and a secondary investigator was performed to identify the use of growth factors in periodontics for the literature review. The articles that were identified by this systematic review were analyzed in detail, which included the study of their inclusion and exclusion criteria, outcome measures determination and analysis, risk of bias, adverse events, and conclusions or inference of the efficacy of growth factors to the general population. Five papers fulfilled the inclusion criteria. Two papers were identified that had sufficiently similar study design that a meta-analysis of their outcomes was possible. Most of the reported outcomes from the selected papers were descriptive. The articles demonstrated periodontal regeneration at least comparable to their respective positive controls, with only a couple of articles demonstrating significantly greater outcomes compared to their respective positive controls. Histologic evidence demonstrated greater periodontal regeneration when using growth factors compared to other regenerative techniques and an increased healing and bone maturation rate compared to other regenerative and bone augmentation techniques in these human studies. Within the limits of this systematic review, the use of recombinant human platelet-derived growth factor-BB (rhPDGF-BB) led to greater clinical attachment level gain of ≈1 mm compared to an osteoconductive control, β-tricalcium phosphate (β-TCP). The use of rhPDGF-BB led to greater percentage bone fill of ≈40% compared to the osseoconductive control, β-TCP. Last, the use of rhPDGF-BB led to an increased rate of bone growth of ≈2 mm compared to the osseoconductive control, β-TCP.

Dose‐dependent effect of radiation on titanium implants: a quantitative study in rabbits

The aim of the study was to investigate the dose-dependent effect of radiation on dental implant stability and osseointegration using a series of quantitative analyses. Six rabbits were randomly assigned to 15 and 30 Gy radiation groups. Each rabbit received radiation at the tibial and femoral metaphyseal region of left hind leg. The right leg was used as control. Implant surgery was performed on tibial and femoral metaphyses after 1 week. Totally 24 implants were inserted. The animals were killed at postoperative week four. Implant stability was measured using resonance frequency analysis. Ratio of bone volume to total volume (BV/TV), rate of bone growth, and bone-to-implant contact (BIC) were assessed using micro-computed tomography (micro-CT), fluorochrome labeling analysis, and histomorphometric analysis, respectively. After 4 weeks of healing, all implants were integrated (n = 6). Implant stability was significantly compromised by 15 Gy (P = 0.010) and 30 Gy (P = 0.025) of radiation. Radiation decreased BV/TV, and the significant effect was detected at the dose of 15 Gy (P = 0.008) and 30 Gy (P < 0.001). Bone growth in osseointegration was impaired by radiation. In 15 Gy group, the radiation side showed significant lower rate of bone growth than the control side at week 3 (P = 0.001), while the undistinguishable signals on 30 Gy radiation side suggested the low rate of new bone formation at each time point. Histomorphological BIC had no significant difference between 15 Gy control side and 15 Gy radiation side. 30 Gy radiation side showed a significantly lower BIC than 30 Gy control side (P < 0.001) as well as 15 Gy radiation side (P < 0.001). Implant stability and osseointegration were compromised by radiation. Radiation compromised osseointegration in a dose-dependent manner.

Reliability of panoramic radiography in chronological age estimation

Introduction:There has been a strong relationship between the growth rate of bone and teeth, which can be utilized for the purpose of age identification of an individual.Aims and Objective:The present study was designed to determine the relationship between the dental age, the age from dental panoramic radiography, skeletal age, and chronological age.Materials and Methods:The study included 270 individuals, averaging between 17 years and 25 years of age from out-patient department of New Horizon Dental College and Hospital, Sakri, Bilaspur, Chhattisgarh, India, for third molar surgery. Panoramic and hand wrist radiographs were taken, the films were digitally processed for visualization of the wisdom teeth. The confirmations of ages were repeated again at an interval of 4 weeks by a radiologist. The extracted wisdom teeth were placed in 10% formalin and were examined by one dental surgeon to estimate the age on the basis of root formation. Student's t-test was adopted for statistical analysis and probability (P value) was calculated.Conclusion:Estimating the age of an individual was accurate by examining extracted third molar. Age estimation through panoramic radiography was highly accurate in upper right quadrant (mean = 0.72 and P = 0.077).

Effects of Laser Acupuncture on Longitudinal Bone Growth in Adolescent Rats

Longitudinal bone growth is the results of chondrocyte proliferation and hypertrophy and subsequent endochondral ossification in the growth plate. Recently, laser acupuncture (LA), an intervention to stimulate acupoint with low-level laser irradiation, has been suggested as an intervention to improve the longitudinal bone growth. This study investigated the effects of laser acupuncture on growth, particularly longitudinal bone growth in adolescent male rats. Laser acupuncture was performed once every other day for a total of 9 treatments over 18 days to adolescent male rats. Morphometry of the growth plate, longitudinal bone growth rate, and the protein expression of BMP-2 and IGF-1 in growth plate were observed. The bone growth rate and the heights of growth plates were significantly increased by laser acupuncture. BMP-2 but not IGF-1 immunostaining in growth plate was increased as well. In conclusion, LA promotes longitudinal bone growth in adolescent rats, suggesting that laser acupuncture may be a promising intervention for improving the growth potential for children and adolescents.

Do Higher Temperatures Increase Growth in the Nocturnal GeckoHomonota darwini(Gekkota: Phyllodactylidae)? A Skeletochronological Assessment Analyzed at Temporal and Geographic Scales

Abstract Recent studies predict that several lineages of tropical animals are at particular risk given current estimates of global climate change. Yet, much uncertainty exists on the effects of climate shifts in ectothermic species from cool temperate regions such as Patagonia. In this study, we focus on the impact of environmental temperature on growth, age at sexual maturity, and life-span of the Patagonian gecko Homonota darwini. Skeletochronological methods were used to assess the bone growth rates of individuals from three populations at different geographic and temporal scales: two populations from Chubut (warm site; 1941 and 2010) and one population from Rio Negro (cold site; 1997–1998). Populations displayed similar bone arrangement and the growth patterns fit a von Bertalanffy curve. Three populations attained reproductive size at a minimum age of 3 yr, but at the cold site two specimens were shown to mature in 4 yr. We found no differences in juvenile growth rates in body size or bone zone width...

Bone metabolism, growth rate and pubertal development in children with chronic myeloid leukemia treated with imatinib during puberty

Imatinib mesylate (IM, Glivec®) and the 2 nd generation tyrosine kinase inhibitors (TKIs) (dasatinib and nilotinib) are the standard treatment for children and adults with chronic myeloid leukemia (CML). IM inhibits all ABL tyrosine kinases and selectively suppresses the ATP-binding site of

Amomum villosum induces longitudinal bone growth in adolescent female rats

ObjectiveThis study was conducted to evaluate the effect of Amomum villosum on longitudinal bone growth. MethodsAdolescent female Sprague-Dawley rats were divided into 3 groups and treated for 4 days: control (distilled water, p.o.), recombinant human growth hormone (rhGH; 100 μg/kg, s.c.), and A. villosum (500 mg/kg, p.o.) groups. On day 3, tetracycline (20 g/kg, i.p.) was injected for growth plate identification. On days 2, 3 and 4, 5-bromo-2′-deoxyuridine (BrdU) (50 mg/kg, i.p.) was injected to label proliferating cells. On day 5, tibias were dissected and fixed in 4% paraformaldehyde, dehydrated, and sectioned for immunohistochemistry and histomorphometry. ResultsThe rate of bone growth in the A. villosum and rhGH groups increased to (410 ± 44) and (389 ± 46) μm/day (P<0.01), respectively, as compared with the control (330.7 ± 34.7) μm/day. The thickness of the growth plates also increased to (591 ± 37) and (598 ± 32) μm, respectively, as compared with the control (524±89) μm (P<0.001). The number of BrdU-positive cells in the chondrocytes of the A. villosum and rhGH groups was also significantly higher (126±24) and (143±18) cells/mm2, respectively) than in the control (109 ± 25) mm2 (P<0.05). Insulin-like growth factor-1 and bone morphogenetic protein-2 in the A. villosum and rhGH groups were highly expressed in the growth plate as compared with the control samples, indicating increased bone formation. ConclusionsA. villosum could be used to treat growth retardation during adolescence.