Collagen Quality Research Articles

Role of FAM134 paralogues in endoplasmic reticulum remodeling, ER-phagy, and Collagen quality control

Degradation of the endoplasmic reticulum (ER) via selective autophagy (ER-phagy) is vital for cellular homeostasis. We identify FAM134A/RETREG2 and FAM134C/RETREG3 as ER-phagy receptors, which predominantly exist in an inactive state under basal conditions. Upon autophagy induction and ER stress signal, they can induce significant ER fragmentation and subsequent lysosomal degradation. FAM134A, FAM134B/RETREG1, and FAM134C are essential for maintaining ER morphology in a LC3-interacting region (LIR)-dependent manner. Overexpression of any FAM134 paralogue has the capacity to significantly augment the general ER-phagy flux upon starvation or ER-stress. Global proteomic analysis of FAM134 overexpressing and knockout cell lines reveals several protein clusters that are distinctly regulated by each of the FAM134 paralogues as well as a cluster of commonly regulated ER-resident proteins. Utilizing pro-Collagen I, as a shared ER-phagy substrate, we observe that FAM134A acts in a LIR-independent manner and compensates for the loss of FAM134B and FAM134C, respectively. FAM134C instead is unable to compensate for the loss of its paralogues. Taken together, our data show that FAM134 paralogues contribute to common and unique ER-phagy pathways.

Dealing with minor differences in bone matrix: can spectra follow the DNA preservation?

ABSTRACT Attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy is a relatively fast and inexpensive but reliable method that can be used as a rough screening tool for DNA preservation. Although it is an excellent analytical tool, it only provides relative information on the chemical structure of heterogeneous materials such as bone and its usefulness and accuracy for predicting the preservation of DNA in samples originating from different body regions of minimally altered remains was never tested before. 144 bone samples were collected from different body regions of three individuals discovered in a Second World War mass grave. DNA was extracted and quantified, followed by STR typing. Samples were analysed with ATR-FTIR spectroscopy. Comparing the preservation state of DNA and chemometric indices, the usefulness of the method was tested. Correlations between the DNA preservation and chemometric indices were highly variable, especially when considering different body regions. Best DNA preservation was correlated with a balanced ratio between carbonates and phosphates, and with high collagen quality and quantity. It seems that, when dealing with relatively young and well-preserved remains, more attention should be paid to collagen quality. In addition, the results indicate that DNA quality and DNA quantity correlate differently with chemometric indices.

Effect of Light-Emitting Diode Phototherapy on Allograft Bone After Open Sinus Lift Surgery: A Randomized Clinical Trial (Concurrent Parallel).

Introduction: Phototherapy with a light-emitting diode (LED) is used in medicine due to its potential bio-stimulatory effects on the human body. However, controversy still exists regarding the efficacy of low-level laser therapy (LLLT) and phototherapy with LED. This in vivo study aimed to quantitatively and qualitatively assess the newly formed bone following LED phototherapy of the human maxillary sinuses. Methods: This randomized clinical trial (concurrent parallel) was conducted on 44 patients in two groups (n=22) at the Implant Department of Tehran University of Medical Sciences. Randomization was done by a random sequence generator program. The inclusion criteria were absence of chronic sinusitis and chronic bone marrow conditions, no history of surgery at the site, absence of diabetes mellitus, no history of chemotherapy or radiotherapy, maxillary premolar edentulism, and signing informed consent forms. Group A underwent LED phototherapy with 620 ± 2 nm wavelength for 20 minutes daily for a total of 21 days after sinus lift surgery. Group B served as the control group and did not receive phototherapy. After 6 months, the grafted sites were re-opened for implant placement, and bone biopsy samples were obtained using a trephine bur. The samples were stained with hematoxylin and eosin and inspected under a light microscope. The results were statistically analyzed using the Mann-Whitney U test. Both the surgeon and pathologist were blinded to the group allocation of patients. Results: Forty tissue specimens were analyzed. Insignificant differences existed between the two groups in terms of the degree of inflammation, bone quality, and maturity of collagen. Histological analyses revealed no significant difference in the mineralized areas of bone between the two groups (P >0.05). Conclusion: The results indicated that LED phototherapy cannot significantly enhance osteogenesis after sinus lift surgery. No side effects were observed in the experimental group.

Correlation between epithelial-mesenchymal transition and collagen quality in oral dysplasia and squamous cell carcinoma

Epithelial-mesenchymal transition (EMT) enhances the invasive ability, providing an explanation for the mechanism of tumor metastasis. The stiffness of the stromal extracellular matrix collagen can regulate the epithelial cell growth and migration in oral epithelial dysplasia (OED) and oral squamous cell carcinoma (OSCC). Objectives: to study the epithelial expression of Vimentin as a marker for EMT and to elucidate the nature of collagen in OED and OSCC and finally to correlate EMT to collagen quality in these lesions. Material and methods: the area fraction of immunohistochemical epithelial expression of Vimentin and color polarization of picrosirius red stained collagen fibers were detected in ten specimens of each grade of OED and OSCC as well as normal oral mucosa followed by statistical analysis. Results: a statistically significant increase in the median area fractions of epithelial Vimentin expression and yellow-green fibers were detected as the grade of OED and OSCC progressed. Spearman’s correlation coefficient revealed a statistically significant direct correlation between epithelial Vimentin expression and yellow-green fibers in these lesions. Conclusion: there was a statistically significant increase in EMT and decrease in the collagen quality with the advance of OED and dedifferentiation of the neoplasm. The significant inverse correlation between EMT and collagen quality indicates the role of EMT in stromal collagen quality in these lesions and aid in their prognosis.

Providing Optimal Rejuvenation to the Jawline and Perioral Area Using Neuromodulators and Hyaluronic Acid Dermal Fillers.

Including the jawline in aesthetic assessment has become increasingly popular when using both surgical and nonsurgical techniques. Facial aging processes include bone resorption, fat pad atrophy, and a breakdown of the quality of collagen and elastin in the skin. To provide optimal treatment of the jawline using nonsurgical techniques, it is important to consider all of these aspects before planning treatment. Men and women have different facial aging processes and ideal facial ratios that must be respected. The objective of this article is to discuss the use of botulinum toxin A and hyaluronic acid filler injectable treatments, deoxycholic acid injectable treatments, and cryolipolysis treatments and explain how these treatments can be utilized for optimal rejuvenation of the jawline and perioral area.

Comparison of different protocols for demineralization of cortical bone

Bone is a biological composite material consisting of two main components: collagen and mineral. Collagen is the most abundant protein in vertebrates, which makes it of high clinical and scientific interest. In this paper, we compare the composition and structure of cortical bone demineralized using several protocols: ethylene-diamine-tetraacetic acid (EDTA), formic acid (CH2O2), hydrochloric acid (HCl), and HCl/EDTA mixture. The efficiencies of these four agents were investigated by assessing the remaining mineral quantities and collagen integrity with various experimental techniques. Raman spectroscopy results show that the bone demineralized by the CH2O2 agent has highest collagen quality parameter. The HCl/EDTA mixture removes the most mineral, but it affects the collagen secondary structure as amide II bands are shifted as observed by Fourier transform infrared spectroscopy. Thermogravimetric analysis reveals that HCl and EDTA are most effective in removing the mineral with bulk measurements. In summary, we conclude that HCl best demineralizes bone, leaving the well-preserved collagen structure in the shortest time. These findings guide on the best demineralization protocol to obtain high-quality collagen from bone for clinical and scientific applications.

Influence of low dose naltrexone on Raman assisted bone quality, skeletal advanced glycation end-products and nano-mechanical properties in type 2 diabetic mice bone

Type 2 diabetes mellitus (T2DM) commonly affects the bone mineral phase and advanced glycation end-products (AGEs) which eventually led to changes in bone material properties on the nano and macro-scale. Several anti-diabetic compounds are widely used to control high blood sugar or glucose caused by T2DM. Low Dose Naltrexone (LDN), an opiate receptor antagonist, and a known TLR4 antagonist, treatment can improve glucose tolerance and insulin sensitivity in high-fat-diet (HFD) induced T2DM mice. However, the influences of LDN on the local bone quality, mineralization of the bone, and the skeletal AGEs levels have not been fully elucidated. The objective of this study is to understand the effect of LDN on Raman assisted bone quality, skeletal AGEs (determined by Raman spectroscopy), and nano-mechanical properties in HFD induced T2DM mice bone. In order to investigate these, mice and corresponding bones were divided into four groups (divided based on diet and treatment), (a) normal control diet treated with saline water, (b) normal control diet treated with LDN, (c) HFD treated with saline water, and (d) HFD treated with LDN. In T2DM condition (HFD treated with saline water), alteration of Raman-based compositional measures in bone quality including mineral-to-matrix ratios, carbonate substitution, mineral crystallinity, and collagen quality was observed. Our data also indicated that T2DM enhances the skeletal AGEs, and impairs the nano-mechanical properties. Interestingly, present results indicated that LDN controls the Raman-based compositional measures in bone quality in HFD induced T2DM mice bone. Additionally, LDN also protects the alteration of the skeletal AGEs levels and nano-mechanical properties in T2DM mice bone. This study concluded that LDN can control the HFD induced T2DM affected bone abnormalities at multiple hierarchical levels.

Micro-Computed Tomography: Teknologi pencitraan mikroskopis berbasis Computed Tomography dan pengunaannya dalam analisis kualitas tulang

Objectives: The literature review will briefly review the development of micro-CT as a microscopic radiographic modality in the field of dental research for bone analysis
 Literature Review: Bone quality values ​​represent the mechanical and biological characteristics of bone mass; structural properties including geometry, macrostructure, and microstructure; and tissue properties including modulus elasticity, mineral density, collagen quality, and character cells and bone marrow. Assessment of bone quality is carried out clinically, both locally and systemically, for various disease or therapeutic conditions. The use of micro-CT is growing prominently and effectively as a modality for analysis and evaluation of bone quality because various morphometric parameters to the microstructural level can be obtained. It applies to the analysis of osseointegration of dental implants and the healing conditions of pathological defects.
 Conclusion: In conclusion, micro-CT with very high resolution is accurate in the analysis of bone quality because the imaging results can provide microstructure morphometric values ​​in osseointegration conditions after dental implant installation and post-fracture biomechanical characteristics, which can be an essential scientific basis for various experimental bone analysis research designs.

Role of myofibroblasts and collagen quality in elaboration of debatable nature of odontogenic keratocyst

Odontogenic keratocyst (OKC) is one of the debatable odontogenic lesions. The need for more researches in order to determine the true nature of this lesion was one of the WHO’s recommendations in 2016. Stromal reactions to epithelial neoplasms are marked by the appearance of alpha smooth muscle actin (α-SMA) positive myofibroblasts (MFs). Stromal collagen has a vital role in pathogenesis of odontogenic lesions. Objectives: to compare the count of α-SMA positive MFs, collagen quality and packing in OKC, in relation to dentigerous cyst and ameloblastoma. Material and methods: α-SMA immunohistochemically positive MFs count, as well as the fraction of yellow-green fibers to detect the collagen quality and packing using picrosirius red staining with polarized light microscope, were compared in 11 samples of each of ameloblastoma, OKC and dentigerous cyst. Statistical analysis was performed. Results: the average number of MFs were 53.7, 41.9 and 11.3 in ameloblastoma, OKC and dentigerous cysts respectively with statistically significant differences (P-value

Isotopic evidence of possible long‐distance freshwater fish trade in the 13th to 14th century Chełm, modern Poland

AbstractThe Middle Ages in the Polish Plain saw an increase in fish consumption as it substituted meat during Lent and other meatless days, approximately one third of the year, due to religious restrictions. Demand for fish stimulated the market. Fish trade and distribution can be easily reconstructed regarding marine species; however, freshwater taxa evade such reconstructions. Modern analytical tools, such as stable isotope analysis, can distinguish freshwater fish inhabiting brackish water typical of estuaries from individuals occupying inland water reservoirs. In this study, carbon and nitrogen stable isotope analysis was conducted for fish remains excavated from mid‐13th to 14th century residential complex from Wysoka Górka at Chełm, modern Poland. Samples of 16 individuals representing nine taxa met the collagen quality criteria. Half of the individuals expressed δ13C values typical of marine environment: four sturgeons (Acipenser oxyrinchus), two catfishes (Silurus glanis), a pike (Esox lucius) and a bream (Abramis brama). Such values are expected for sturgeon, an anadromous fish, but not typical for freshwater taxa from the sites deep inland, like Chełm. The results are discussed whether freshwater fish are of local origin, migrated in the area of Chełm, or were item of trade, probably from the Baltic coast (approximately 450 km); however, the presence of carp (Cyprinus carpio) may indicate the basin of the Black Sea.

Linking structural and compositional changes in archaeological human bone collagen: an FTIR-ATR approach

Collagen is the main structural and most abundant protein in the human body, and it is routinely extracted and analysed in scientific archaeology. Its degree of preservation is, therefore, crucial and several approaches are used to determine it. Spectroscopic techniques provide a cost-effective, non-destructive method to investigate the molecular structure, especially when combined with multivariate statistics (chemometric approach). In this study, we used FTIR-ATR spectroscopy to characterise collagen extracted from skeletons recovered from necropoleis in NW Spain spanning from the Bronze Age to eighteenth century AD. Principal components analysis was performed on a selection of bands and structural equation models (SEM) were developed to relate the collagen quality indicators to collagen structural change. Four principal components represented: (i) Cp1, transformations of the backbone protein with a residual increase in proteoglycans; (ii) Cp2, protein transformations not accompanied by changes in proteoglycans abundance; (iii) Cp3, variations in aliphatic side chains and (iv) Cp4, absorption of the OH of carbohydrates and amide. Highly explanatory SEM models were obtained for the traditional collagen quality indicators (collagen yield, C, N, C:N), but no relationship was found between quality and δ13C and δ15N ratios. The observed decrease in C and N content and increase in C:N ratios is controlled by the degradation of protein backbone components and the relative preservation of carbon-rich compounds, proteoglycans and, to a lesser extent, aliphatic moieties. Our results suggest that FTIR-ATR is an ideal technique for collagen characterization/pre-screening for palaeodiet, mobility and radiocarbon research.

Advanced glycation end products cause RAGE-dependent annulus fibrosus collagen disruption and loss identified using in situ second harmonic generation imaging in mice intervertebral disk in vivo and in organ culture models.

Aging and diabetes are associated with increased low‐back pain and intervertebral disk (IVD) degeneration yet causal mechanisms remain uncertain. Advanced glycation end products (AGEs), which accumulate in IVDs from aging and are implicated in diabetes‐related disorders, alter collagen and induce proinflammatory conditions. A need exists for methods that assess IVD collagen quality and degradation in order to better characterize specific structural changes in IVDs due to AGE accumulation and to identify roles for the receptor for AGEs (RAGE). We used multiphoton microscopy with second harmonic generation (SHG), collagen‐hybridizing peptide (CHP), and image analysis methods to characterize effects of AGEs and RAGE on collagen quality and quantity in IVD annulus fibrosus (AF). First, we used SHG imaging on thin sections with an in vivo dietary mouse model and determined that high‐AGE (H‐AGE) diets increased AF fibril disruption and collagen degradation resulting in decreased total collagen content, suggesting an early degenerative cascade. Next, we used in situ SHG imaging with an ex vivo IVD organ culture model of AGE challenge on wild type and RAGE‐knockout (RAGE‐KO) mice and determined that early degenerative changes to collagen quality and degradation were RAGE dependent. We conclude that AGE accumulation leads to RAGE‐dependent collagen disruption in the AF and can initiate molecular and tissue level collagen disruption. Furthermore, SHG and CHP analyzes were sensitive to collagenous alterations at multiple hierarchical levels due to AGE and may be useful in identifying additional contributors to collagen damage in IVD degeneration processes.

Characterization chemical composition of skin and head bones barracuda (Sphyraena jello) as collagen raw material

Barracuda is one type of fish that is widely used in the diversification of processing fishery products. This business will increase the amount of waste if it is not managed optimally. This study aims to utilize fish skin and head bones as raw material for collagen, which can reduce the amount of fish processing waste and provide added value to the waste. Barracuda skin and head bones that will be used as a raw material in the manufacture of collagen are first characterized by analysis of the chemical composition of the skin, which includes water, ash, protein, fat content. This chemical composition analysis aims to assess the initial feasibility of barracuda skin and head bones as raw material for collagen. The results of proximate analysis of the skin and head bones of barracuda (Sphyraena jello) showed a water content of 67.39%; 22.56%, ash content 2.53%; 58.45%, protein content 21.69%; 14.32%, and fat content of 8.38%; 4.58%. Barracuda skin and head bones are still fresh in terms of the value of water content that is still in the range of water content of the skin and head bones in general. High protein levels in the skin compared to head bones barracuda allows it to be used as raw material for collagen. Barracuda skin and bone fat levels are high enough, so pretreatment needs to do to remove fat and minerals so that it can improve the quality of collagen produced.

Quality control for modern bone collagen stable carbon and nitrogen isotope measurements

Abstract Isotopic analyses of collagen, the main protein preserved in subfossil bone and tooth, has long provided a powerful tool for the reconstruction of ancient diets and environments. Although isotopic studies of contemporary ecosystems have typically focused on more accessible tissues (e.g. muscle, hair), there is growing interest in the potential for analyses of collagen because it is often available in hard tissue archives (e.g. scales, skin, bone, tooth), allowing for enhanced long‐term retrospective studies. The quality of measurements of the stable carbon and nitrogen isotopic compositions of ancient samples is subject to robust and well‐established criteria for detection of contaminants and diagenesis. Among these quality control (QC) criteria, the most widely utilized is the atomic C:N ratio (C:NAtomic), which for ancient samples has an acceptable range between 2.9 and 3.6. While this QC criterion was developed for ancient materials, it has increasingly being applied to collagen from modern tissues. Here, we use a large survey of published collagen amino acid compositions (n = 436) from 193 vertebrate species as well as recent experimental isotopic evidence from 413 modern collagen extracts to demonstrate that the C:NAtomic range used for ancient samples is not suitable for assessing collagen quality of modern and archived historical samples. For modern tissues, collagen C:NAtomic falling outside 3.00–3.30 for fish and 3.00–3.28 for mammals and birds can produce systematically skewed isotopic compositions and may lead to significant interpretative errors. These findings are followed by a review of protocols for improving C:NAtomic criteria for modern collagen extracts. Given the tremendous conservation and environmental policy‐informing potential that retrospective isotopic analyses of collagen from contemporary and archived vertebrate tissues have for addressing pressing questions about long‐term environmental conditions and species behaviours, it is critical that QC criteria tailored to modern tissues are established.

A protocol for using attenuated total reflection Fourier-transform infrared spectroscopy for pre-screening ancient bone collagen prior to radiocarbon dating.

Pre-screening of bone collagen quality is important to reduce the cost for analyses such as radiocarbon (14 C) dating with accelerator mass spectrometry in archaeological studies. We developed a pre-screening protocol based on attenuated total reflection (ATR) Fourier-transform infrared spectroscopy (FTIR) for assessing the chemical composition and mineralogy of ancient bone samples. ATR-FTIR measurements were performed on bulk bones of diverse origin and age before collagen extraction. The percentage nitrogen of bulk bones, as well as the weight percentage, and the percentage carbon and nitrogen of extracted organic matter were noted. Several machine learning algorithms were applied to the spectral data and compared for their efficacy in screening for well preserved collagen. The results showed that (a) the first derivative of the spectral data was better suited to screening than the raw FTIR data, especially for a wider spectral range and (b) certain classification algorithms [e.g. gradient boosting machine (GBM)] were able to efficiently predict the degree of preservation in bone samples. This pre-screening protocol can serve as a fast, concise and inexpensive pre-screening tool for determining relative degrees of preservation before collagen extraction and subsequent 14 C dating. The screening power based on the machine learning techniques can be further improved by accumulating the FTIR spectral data of bones.

Determination of Nano-Collagen Quality from Sea Cucumber Holothuria scabra

Sea cucumber contains high collagen protein and potential to be used in cosmetics and health. The aim of this study are to determine the quality of sea cucumber collagen using hydrochloric acid with different concentrations and the quality of nano-collagen using stirrer magnetic in different stirring times. This study was conducted by an experimental method using stages of the collagen extraction process and manufacture of nano-collagen. Process of extracting sea cucumber meat collagen using different concentrations of HCl (4%, 5%, and 6%), and process of making nano-collagen using 96% ethanol solution with different stirring times (one, two, three hours). Sea cucumber collagen with the 6% HCl extraction process obtained optimally results with collagen yield of 20.76%, white degree 73.97%, moisture level 10.99%, protein 98.3%, ash 0.86%, fat 0.59%, and collagen pH 3.92. The functional groups in collagen in accordance with the standard collagen compounds. The nano-collagen obtained was in the form of a creamy white powder (79.25% white degree), moisture 9.11%, ash 0.68%, fat 0.51%, protein 98.9%, pH 3.98, and particle size 285 nm.

First screening of collagen quality in Lebanese archaeological bones

Radiocarbon dating is a crucial tool for studying national cultural heritage and reconstructing ancient human history. Uncalcined bones, alongside seeds and charcoal, are one of the most reliable materials to be dated, and more precisely the collagen which constitutes around 30% by weight of the whole bone. However, this collagen may not be well preserved due to the effect of physical and chemical properties of the burial environment. Radiocarbon dating of low-collagen bones could be costly, time consuming and cause destruction of valuable archaeological samples without getting reliable ages. Many techniques were developed to test the state of collagen in bone samples. In this work, an Elemental Analyzer was used on twenty-one bone samples to determine %N, C/N ratio and to calculate %C excess as indicator parameters of collagen preservation. All samples were collected from four coastal Lebanese archeological sites. Percentage nitrogen in 15 samples was below the threshold value 0.7% and hence they were not adequate for radiocarbon dating. The ratio C/N in the majority of the samples was higher than 5 indicating extensive diagenetic alteration or contamination by exogenous carbon. The percentages excess carbon were lower than maximum acceptable values 5-10%. Our results emphasize on the importance of collagen prescreening when dating local bone samples which are in many cases degraded.

THE CHARACTERISTICS OF NANOPARTICLE QUALITY OF SAND SEA CUCUMBER (Holothuria scabra) MEAT COLLAGEN WITH DIFFERENT STIRRING TIME

This research was aimed to determine the characteristics of nanoparticle quality of sand sea cucumber meat collagen (Holothuria scabra) with different stirring time. The method was carried out experimentally by conducting an experiment on nanoparticles of meat sand sea cucumber (Holothuria scabra) with different stirring i.e. 1, 2 and 3 hours. The results showed that on the fresh of meat sand sea cucumber has moisture, protein, ash, fat, and carbohydrate content was 78.94%, 79.67%, 6.74%, 4.82%, and 8.77%, respectively. The nanoparticles of collagen produced showed that different stirring time was affected by the quality characteristics of nanoparticles of sea cucumber meat collagen. The best result was obtained at 3 hours of stirring time which produced collagen nanoparticles with a yield rate of 14.33%, moisture 65.79%, ash 0.70%, protein 98.23%, pH 3.83 and particle size 950 nm.

Glimpses into the molecular pathogenesis of Peyronie’s disease

Peyronie's disease (PD) is a fibroproliferative disease of the penis. Since little is known about the molecular pathogenesis of PD, we compared the biochemical make-up of PD plaques with normal tunica albuginea to clarify pathological processes in the scarred tissue. Protein and mRNA levels were measured in plaques and in unaffected pieces of the tunica albuginea. We investigated the presence of myofibroblasts, the deposition of collagens, and some key elements of Wnt and YAP1 signaling at protein level. The expression of 45 genes, all related to collagen homeostasis and extracellular matrix proteins, was quantified. In plaques, more myofibroblasts were present, and we observed an activation of Wnt signaling and YAP1 signaling. Increased levels of the collagens types I and III confirm the fibrotic nature of plaques. The mRNA ratio of collagen types III, IV, and VI to type I was increased. The expression of lysyl hydroxylase 3 was higher, whereas a decreased expression level was seen for fibronectin and cathepsin K. The biochemical composition of plaques was different from unaffected tunica albuginea: the relative and absolute abundance of various extracellular matrix proteins were changed, as well as the quality of collagen and the level of the collagen-degrading enzyme cathepsin K.

Intermittent parathyroid hormone 1\u201334 induces oxidation and deterioration of mineral and collagen quality in newly formed mandibular bone

Intermittent parathyroid hormone (PTH) administration is known to promote bone healing after surgical procedures. However, the mechanism and influence of PTH on the mineral and collagen quality of the jaw are not well understood. Most studies have focused on analyzing the bone density and microstructure of the mandible, and have insufficiently investigated its mineral and collagen quality. Oxidative stress activates osteoclasts, produces advanced glycation end products, and worsens mineral and collagen quality. We hypothesized that PTH induces oxidation and affects the mineral and collagen quality of newly formed mandibular bone. To test this, we examined the mineral and collagen quality of newly formed mandibular bone in rats administered PTH, and analyzed serum after intermittent PTH administration to examine the degree of oxidation. PTH administration reduced mineralization and worsened mineral and collagen quality in newly formed bone. In addition, total anti-oxidant capacity in serum was significantly decreased and the oxidative-INDEX was increased among PTH-treated compared to vehicle-treated rats, indicating serum oxidation. In conclusion, intermittent administration of PTH reduced mineral and collagen quality in newly formed mandibular bone. This effect may have been induced by oxidation.