Structural changes in cartilage and collagen studied by high temperature Raman spectroscopy

Understanding the high temperature behavior of collagen and collagenous tissue is important for surgical procedures and biomaterials processing for the food, pharmaceutical, and cosmetics industries. One primary event for proteins is thermal denaturation that involves unfolding the polypeptide chains while maintaining the primary structure intact. Collagen in the extracellular matrix of cartilage and other connective tissue is a hierarchical material containing bundles of triple-helical fibers associated with water and proteoglycan components. Thermal analysis of dehydrated collagen indicates irreversible denaturation at high temperature between 135°C and 200°C, with another reversible event at ∼60-80°C for hydrated samples. We report high temperature Raman spectra for freeze-dried cartilage samples that show an increase in laser-excited fluorescence interpreted as conformational changes associated with denaturation above 140°C. Spectra for separated collagen and proteoglycan fractions extracted from cartilage indicate the changes are associated with collagen. The Raman data also show appearance of new features indicating peptide bond hydrolysis at high temperature implying that molecular H2O is retained within the freeze-dried tissue. This is confirmed by thermogravimetric analysis that show 5-7 wt% H2O remaining within freeze-dried cartilage that is released progressively upon heating up to 200°C. Spectra obtained after exposure to high temperature and re-hydration following recovery indicate that the capacity of the denatured collagen to re-absorb water is reduced. Our results are important for revealing the presence of bound H2O within the collagen component of connective tissue even after freeze-drying and its role in denaturation that is accompanied by or perhaps preceded by breakdown of the primary polypeptide structure

Proposed reference models for nitrous oxide and methane in the middle atmosphere

Data from the Stratospheric and Mesospheric Sounder (SAMS) on the Nimbus 7 satellite, for the period from Jan. 1979 - Dec. 1981, are used to prepare a reference model for the long-lived trace gases, methane and nitrous oxide, in the stratosphere. The model is presented in tabular form on seventeen pressure surfaces from 20 to 0.1 mb, in 10 degree latitude bins from 50S to 70N, and for each month of the year. The means by which the data quality and interannual variability, and some of the more interesting globally and seasonally variable features of the data are discussed briefly

Exposure of a tendon extracellular matrix to synovial fluid triggers endogenous and engrafted cell death: A mechanism for failed healing of intrathecal tendon injuries

Aim: The purpose of this study was to investigate the effect of normal synovial fluid (SF) on exposed endogenous tendon-derived cells (TDC) and engrafted mesenchymal stem cells (MSCs) within the tendon extracellular matrix. Methods: Explants from equine superficial digital flexor (extra-synovial) and deep digital flexor tendons (DDFT) from the compressed, intra-synovial and the tensile, extra-synovial regions were cultured in allogeneic or autologous SF-media. Human hamstring explants were cultured in allogeneic SF. Explant viability was assessed by staining. Proliferation of equine monolayer MSCs and TDCs in SF-media and co-culture with DDFT explants was determined by alamarblue®. Non-viable Native Tendon matrices (NNTs) were re-populated with MSCs or TDCs and cultured in SF-media. Immunohistochemical staining of tendon sections for the apoptotic proteins caspase-3, -8 and -9 was performed. Results: Contact with autologous or allogeneic SF resulted in rapid death of resident tenocytes in equine and human tendon. SF did not affect the viability of equine epitenon cells, or of MSCs and TDCs in monolayer or indirect explant co-culture. MSCs and TDCs, engrafted into NNTs, died when cultured in SF. Caspase-3, -8 and -9 expression was greatest in SDFT explants exposed to allogeneic SF. Conclusions: The efficacy of cells administered intra-synovially for tendon lesion repair is likely to be limited, since once incorporated into the matrix, cells become vulnerable to the adverse effects of SF. These observations could account for the poor success rate of intra-synovial tendon healing following damage to the epitenon and contact with SF, common with most soft tissue intra-synovial pathologies

Precision validation of MIPAS-Envisat products

This paper discusses the variation and validation of the precision, or estimated random error, associated with the ESA Level 2 products from the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS). <br><br> This quantity represents the propagation of the radiometric noise from the spectra through the retrieval process into the Level 2 profile values. The noise itself varies with time, steadily rising between ice decontamination events, but the Level 2 precision has a greater variation due to the atmospheric temperature which controls the total radiance received. Hence, for all species, the precision varies latitudinally/seasonally with temperature, with a small superimposed temporal structure determined by the degree of ice contamination on the detectors. <br><br> The precision validation involves comparing two MIPAS retrievals at the intersections of ascending/descending orbits. For 5 days per month of full resolution MIPAS operation, the standard deviation of the matching profile pairs is computed and compared with the precision given in the MIPAS Level 2 data, except for NO₂ since it has a large diurnal variation between ascending/descending intersections. Even taking into account the propagation of the pressure-temperature retrieval errors into the VMR retrieval, the standard deviation of the matching pairs is usually a factor 1&ndash;2 larger than the precision. This is thought to be due to effects such as horizontal inhomogeneity of the atmosphere and instability of the retrieval

EFFICACY OF TERIPARATIDE IN COMMINUTED FRACTURE HEALING IN LOWER LIMB: A RETROSPECTIVE STUDY

Objective: The objective of the study was to show the efficacy of teriparatide in comminuted fracture healing and improvement in overall functional recovery. Methods: A total of 30 subjects who suffered from comminuted fractures of lower limb were selected. Subjects were categorized into two groups: Group A (n=15) contained individuals with teriparatide administration and Group B (n=15) contained individuals who were not administered teriparatide. 20 mg of teriparatide was injected subcutaneously for a period of 3 months. Patients were followed up ay durations of 4, 8, and 12 weeks. Obtained data were entered into Microsoft Excel Worksheets and descriptive analysis was performed. Chi-square test was used to analyze all obtained data. Results: Among Group A patients, the fracture healing rates were found to be significantly earlier with comparison to control group (Group B). Conclusion: Teriparatide was observed to be effective in comminuted fracture healing and has demonstrated good clinical outcome

Fast radiative transfer using monochromatic look-up tables

AbstractLine-by-line (LBL) methods of numerically solving the equations of radiative transfer can be inhibitingly slow. Operational trace gas retrieval schemes generally require much faster output than current LBL radiative transfer models can achieve. One option to speed up computation is to precalculate absorption cross sections for each absorbing gas on a fixed grid and interpolate. This work presents a general method for creating, compressing, and validating a set of individual look-up tables (LUTs) for the 11 most abundant trace gases to use the Reference Forward Model (RFM) to simulate radiances observed by the Infrared Atmospheric Sounding Interferometer (IASI) at a more operational pace. These LUTs allow the RFM to generate radiances more than 20 times faster than LBL mode and were rigorously validated for 80 different atmospheric scenarios chosen to represent variability indicative of Earth׳s atmosphere. More than 99% of all IASI simulated spectral channels had LUT interpolation errors of brightness temperature less than 0.02K, several factors below the IASI noise level. Including a reduced spectral grid for radiative transfer speed up the computation by another factor of six at the expense of approximately doubling interpolation errors, still factors below IASI noise. Furthermore, a simple spectral compression scheme based upon linear interpolation is presented, which reduced the total LUT file size from 120Gbytes to 5.6Gbytes; a compression to just 4.4% of the original. These LUTs are openly available for use by the scientific community, whether using the RFM or to be incorporated into any forward model

Development of a monoclonal anti-ADAMTS-5 antibody that specifically blocks the interaction with LRP1

The potent aggrecanase ADAMTS-5 is constitutively secreted by chondrocytes, but it is rapidly endocytosed in normal cartilage via the cell surface endocytic receptor LRP1. Therefore it is difficult to detect the total ADAMTS-5 activity produced. In this study, we isolated a monoclonal anti-ADAMTS-5 antibody 1B7 that blocks LRP1-mediated internalization without affecting the aggrecanolytic activity. Addition of 1B7 to cultured human chondrocytes revealed the full aggrecanolytic activity of ADAMTS-5 generated by the cells. 1B7 is a useful tool to estimate the ADAMTS-5 activity and to identify its potential roles in the tissues

Efficacy of intra-articular methylprednisolone along with platelet rich plasma vs. platelet rich plasma in early osteoarthritis: a retrospective study

Background: Increased prevalence as well as burden affecting osteoarthritis of knee joint has led to increase in concerns regarding safety of various pharmacological methods. Hence, there is an increase in demand for newer and effective strategies for treatment and manage­ment. Thus, a novel alternate for treatment is required that might repair damage to cartilage rather than simply reduce related symptoms. The aim of this study was to study the efficacy of intra-articular methylprednisolone along with platelet rich plasma versus platelet rich plasma in early knee osteoarthritis. Methods: This retrospective study was conducted on 60 patients diagnosed with initial stages of osteoarthritis of knee according to Kellgren-Lawrence classification. Patients age range was between 40 to 80 years who were divided into 2 groups; group I: It contained 30 subjects treated with intra-articular injections of Platelet Rich Plasma in combination with methylprednisolone and group II: comprised of 30 patients treated with intra-articular injection of Platelet rich Plasma alone. Clinical data pertaining to medical history, VAS and KOOS scores were collected. Statistical analysis was performed using the student’s t test. Results: Statistically significant improvements in VAS and KOOS score values were observed on assessment of scores at baseline, 1, 3 and 6 months intervals, respectively. Conclusions: It can be concluded from the study that a combination therapy of intra-articular injection of combination of PRP with methylprednisolone yields superior results when compared to use of PRP injections alone

Procjena fizikalnih parametrizacija u WRF modelu prilikom simuliranja značajnih obilnih oborina nad područjem indijskog monsuna

In this paper the performance of Weather Research and Forecasting (WRF) model for simulation of heavy rainfall events in presence of monsoon depressions over the Indian monsoon region is investigated with different physics options. A number of experiments for forecasts up to 72 hours are performed with two nested domains at the resolution of 45 km and 15 km respectively. The study shows that WRF model is sensitive to the choice of convective scheme. Betts-Miller-Janjic (BMJ) cumulus scheme is found to produce better results compared to other cumulus schemes for the Indian monsoon region. The model is capable of capturing the movement of the monsoon depression with a lead time of 72 hours. The model is expected to be very useful for forecasting of rainfall and depression tracks in short range time scales over Indian monsoon region.U radu se ispituju performanse WRF modela pri simuliranju obilnih oborina na području indijskog monsuna u vrijeme monsunske depresije za različite odabire fizikalnih shema. Napravljen je veći broj prognostičkih eksperimenata u trajanju do 72 sata, s dvije ugniježđene domene s rezolucijama od 45 km i 15 km. Studija pokazuje da je WRF model osjetljiv na izbor konvektivne sheme. Za područje indijskog monsuna Betts-Miller-Janjic (BMJ) kumulusna shema daje bolje rezultate u odnosu na druge kumulusne sheme. Model je uspio uhvatiti pomicanje monsunske depresije u trajanju do 72 sata. Model može biti vrlo koristan za područje indijskog monsuna u kratkoročnim prognozama prognozu oborine i putanja monsunske depresije