Narrow Results

Despite intensive investigation, normal and abnormal calcification mechanisms are still poorly understood.

In our study we measured the change of main and trace element concentrations across the calcification area of the mandibular cartilage of domestic pigs of different age.

The PIXE method was employed for the analysis of the cartilage samples, using a proton beam with an energy of 1700 keV.

Concentration values of the elements P, S, Cl, K, Fe, Ni, Cu, Zn, Br, Rb, and Sr were evaluated from the measured spectra.

Significant changes of elemental contents across the calcification area could be observed.

The aim of this study was to investigate the effects of electroacupuncture (EA) on the glycoconjugate (GC) changes in articular cartilage in the ankle of an arthritic model. Arthritis was induced by an intraplantar injection of complete Freund's adjuvant (CFA) into the hindpaw of male Sprague-Dawley rats. Bilateral EA stimulation at 2 Hz, 15 Hz and 120 Hz was applied at those acupoints corresponding to Zusanli and Sanyinjiao in man, using needles for 3-day intervals for 30 days. To determine the presence of arthritis, paw edema was measured by a water displacement plethysmometer. Edema of the hindpaw induced by CFA-injection was strongly inhibited by EA stimulation throughout the experimental period. At 30 days after CFA-injection, GC changes of articular cartilage of the ankle joint were observed using conventional and lectin histochemistry. The CFA-injected rat revealed general reduction of staining abilities and lectin affinities for GC in comparison with normal rats. Significant reductions of neutral and acidic GC were observed in interterritorial matrix and chondrocyte capsules, respectively. All lectin affinities examined except DBA were also decreased in CFA-injected rats compared to normal ones. However, EA-treated rats, showed similar staining patterns and lectin affinities for GC as to normal ones, especially neutral GC in interterritorial matrix and sWGA and RCA-1 affinities in chondrocytes. It is concluded that EA in all frequencies examined, especially 2 Hz, can attenuate inflammatory edema in CFA-injected rats through alleviation of alterations of GC components in articular cartilage.

Medicinal herbs have been effectively used for their anti-inflammatory activity, but their exact role has not yet been documented in scientific literature for the management of Osteoarthritis (OA). Since Sida cordifolia L., Piper longum L., Zingiber officinale Rosc., Ricinus communis L., Vitex negundo L. and Tribulus terrestris L. have been widely used in traditional medicine for their anti-inflammatory activity, to evaluate anti-osteoarthritic activity of these herbs, we used a collagenase type II-induced osteoarthritis (CIOA) rat model. Arthritis was induced in wistar rats by intra-articular injection of collagenase type II. Powders of herbs were given orally for 20 days as a suspension in water (270 mg/kg b. wt.). The effects of the treatment in the rats were monitored by physiological parameters like body weight, knee diameter, paw retraction, paw volume, glycosaminoglycan (GAG) release, radiography and histopathology of knee joint. Selected herbs have significantly prevented body weight loss and knee swelling compared to arthritic control (CIOA). All test groups, including indomethacin (standard drug, 3 mg/kg), significantly reduced paw volume compared to CIOA. GAG release in the serum was significantly lowered in herb treated groups compared to indomethacin. The anterior posterior radiographs of S. cordifolia and P. longum treated groups showed a protective effect against OA. Histopathology revealed protection in the structure of the articular cartilage and in chondrocyte pathology as well as reduced clefting. Treatment with herbs has shown chondroid matrix within normal limits. From the results, we observed that S. cordifolia and P. longum possess potent anti-osteoarthritic activity.

Experiments on the transport of radiolabeled Insulin-like Growth Factors (IGF-I and -II) into bovine articular cartilage show differential uptake depending on the relative proportion of IGF-I and -II. In this study, we present a mathematical model describing both the transport and competition of IGF-I and -II for binding sites represented by two functional groupings of IGF binding proteins (IGFBPs). The first grouping has approximately similar binding affinity to both IGF-I and -II (i.e. IGFBPs 1–5), whereas the second group has significantly higher binding preference for IGF-II compared to IGF-I (i.e. IGFBP-6). Using nonlinear least squares, it is shown that the experimental equilibrium competitive binding results can be described using a reversible Langmuir sorption isotherm involving two dominant IGFBP functional groups.

After coupling the sorption model with a poromechanical continuum model, parametric studies are carried out to investigate the effect of model changes including IGF boundary conditions and the ratios of the two IGFBP functional groups. The results show that ignoring competitive binding leads to a significant overestimation of total IGF-I uptake, but an underestimation the rate of "free" (physiologically active) IGF-I within the cartilage. An increase of first group of IGFBPs (i.e. IGFBPs 1–5) as has been reported for osteoarthritis, is observed to hinder the bioavailability of free IGF-I in cartilage, even though the total IGF-I uptake is enhanced. Furthermore, the combination of dynamic compression and competitive binding is seen to enhance the IGF-I uptake within cartilage, but this enhancement is overestimated if competitive binding is neglected.

This study was performed to assess the effect of intra-articularly-injected 3.0% povidone-iodine solution and 2% H₂O₂ on the joint cartilage. Ninety 12-week-old Spraque Dawley rats, weighing 250 g on average, were used; ten were used as controls without any treatment, and 80 were equally divided into four groups for the experiment. In group I, 0.05 ml of normal saline was injected twice into the right knee joints at intervals of one week each, and a running load over a treadmill was added until the animals were sacrificed. In group II, 0.05 ml of 2% H₂O₂ was injected twice into the right knees over the same interval. In group III, 0.05 ml of 2% H₂O₂ was injected twice into the right knees over the same weekly interval, and a running load was added until the knees were sacrificed. In group IV, 0.05 ml of 3.0% povidone-iodine was injected twice into the right knees at one week intervals and a running load was also added until their sacrifice. In each experimental group, five rats were sacrificed at two, four, six and eight weeks after the first intra-articular injection, respectively, and the medial femoral condyles of the joints were taken for histological study of the articular cartilage. After saline injection and running load were applied, stage-I cartilage degeneration was observed at eight weeks after the first saline injection. After H₂O₂ injection only, stage-I cartilage degeneration was observed at four and six weeks, and the changes progressed to Wagenhäuser stage-II degeneration at eight weeks. After H₂O₂ injection and running load were applied, there were no histologic changes by two weeks, but stage-II cartilage degeneration was induced as early as six weeks after the first H₂O₂ injection. After povidone-iodine injection and running load were applied, stage-I cartilage degeration was observed at two weeks, and was maintained up to six weeks. Stage-II degeneration was observed at eight weeks. The matriceal proteoglycan contents was relatively high in comparison with the other groups. Safranin-O stain reduction was observed in groups I, II, III and IV before the histological changes were being observed. From the results, it was found that 3.0% povidone-iodine and 2% H₂O₂ with running loads could induce cartilage damage, and that 3.0% povidone-iodine solution induced more damage to the cartilage than 2% H₂O₂.

Mineralization of the cartilage matrix in embryonic long bones and growth plates is preceded by hypertrophy of chondrocytes. We hypothesize that the swollen hypertrophic cells exert pressure on the matrix, and that this pressure plays a role in the cartilage mineralization process. For this study, we asked the following questions. First, does the ratio of cell volume to matrix volume (CV/MV) increase from the proliferation to the hypertrophic zone in embryonic long bones? Second, is there a correlation between cell-volume increase and the mineralization rate in embryonic and postnatal long bones? The CV/MV ratios in the proliferation and hypertrophic zones in embryonic mouse metatarsals at 17 days of gestational age were determined using morphometric analyses. Confocal laser scanning microscopy was used to determine chondrocyte volumes. Cell volumes in the proliferation and hypertrophic zones of embryonic mouse metatarsals at 17 days of gestational age were compared to the ones in the metatarsal growth plates of nine-day-old mice. The mineralization rate was determined using photographs at 24-hour intervals. The CV/MV increased significantly from the proliferation to the hypertrophic zone, from 1.30±0.15 (mean ± standard deviation) to 1.80±0.18. The relative increase in cell volume from the proliferation to the hypertrophic zone was 1.6 for embryonic cells, i.e. from 370±101 mm³ to 610±107 mm³, and 2.8 for postnatal cells, i.e. from 280±41 mm³ to 786±155 mm³(p<0.05). The mineralization rate was 295±47mm/24 hours and 382±149 mm/24 hours for embryonic and postnatal metatarsals, respectively (p<0.05). The finding that chondrocyte volume increase is accompanied by a higher mineralization rate supports the hypothesis that cell hypertrophy plays an important role during the mineralization process.

The objective of this study is to analyze the effects and benefits of subtotal synovectomy in the early stage of septic arthritis. seventy rabbits with septic arthritis of the left knee joint were treated at 24 or 72 hours after inoculation of Staphylococcus aureus, with different treatment modalities, including antibiotic therapy, arthrotomy, irrigation, and synovectomy. At the end of the 6th week, the knee joints were removed and examined both macroscopically and histologically. It was discovered that there was more significant degeneration at the articular surface of the femur than that of the tibia. antibiotic therapy alone was found to be insufficient to prevent the degeneration of articular cartilage. performing subtotal synovectomy had no statistically significant effect 24 hours after the inoculation of bacteria. However, adding subtotal synovectomy to the surgical drainage 72 hours after inoculation resulted in significantly lesser degeneration of the articular cartilage. Sufficient drainage and irrigation of the joint associated with antibiotic treatment seems to be an adequate choice of treatment at the very early stage of septic arthritis. However, in established septic arthritis, adding subtotal synovectomy to the surgical drainage resulted in significantly lesser degeneration of the articular cartilage.

Conventional histological assessment of tissue requires the removal of tissue from its physiological environment for pathological processing. In this study we report on the development and application of a laser scanning confocal arthroscope (LSCA) capable of in situ histological assessment by confocal microscopy.

The knee joints of three euthanasied adult Merino sheep were imaged using the LSCA and a combination of fluorescent contrasting agents. LSCA images of various tissues were examined for common histological characteristics.

The confocal histology images from the ovine knee acquired during the course of our study illustrated some of the major histological features of chondral and connective tissues.

Our study demonstrates the efficacy of the LSCA for the histological assessment of the chondral and connective tissues of the ovine knee. The LSCA provides an easy and rapid method for assessing the in situ structure of cartilage, muscle, tendon, ligament, meniscus and synovium in their native and unaltered physiological environment. By obviating the need for mechanical biopsy, the LSCA provides a method for the non-destructive assessment of the chondral and connective tissues of the knee, and may be of great benefit in the investigation of orthopedic diseases or in the assessment of newly emerging cartilage repair techniques.

The aim of this study is to investigate the structure and the collagen matrix of the superficial zone of articular cartilage using a 3D imaging technique. The split line thought to represent the orientation of the collagen fibres in the superficial zone was found using Hultkrantz's method. A semitransparent membrane was physically peeled off from the most superficial surface of bovine articular cartilage. Using fibre optic laser scanning confocal microscopy, the collagen matrix in normal cartilage, the membrane and the cartilage with the membrane peeled off were studied. The superficial zone was found to contain a more sophisticated 3D collagenous matrix than previously reported. The collagen matrix in the membrane consists of interwoven long collagen bundles, and the collagen fibres immediately subjacent to it align spatially in a predominantly oblique direction to the articular surface. The split line does not represent the orientation of the collagen in the membrane. This study presents a 3D visualization technique for a minimal-invasive examination of the 3D architecture of the collagen fibres in the superficial zone of articular cartilage, and offers a new insight into the 3D structure of the collagen matrix in the superficial zone of native cartilage.

An extractable bone-inducing agent has recently been identified in freeze-dried preparations of Saos-2 cultured human osteosarcoma cells. Although not all osteoinductive components of Saos-2 cell extracts have been identified, we have shown that Saos-2 cells express high levels of mRNA for bone morphogenetic proteins (BMPs)-1,2,3,4 and 6. Any or all of these BMPs (plus possible unknown factors) may be involved in ectopic bone induction, and may act as paracrine agents, conveying morphogenetic information to juxtaposed osteoprogenitor cells. Our objectives in this study were: 1) to determine whether Saos-2 cells secrete BIA into their culture medium; and 2) if secreted, to determine whether released bone-inducing agent is soluble and/or particulate and contains BMPs. Saos-2 cells were grown to confluence, and then overlaid with serum-free DMEM culture medium for 48 hours. The serum-free conditioned medium was then decanted and filtered through 0.45μ pore-size filters to retain any vesicles or other particulates released by the cells. Particulate protein retained on the 0.45μ filter (designated "retentate") was extracted into 6M urea and bioassayed for bone-inducing activity in Nu/Nu mice, along with soluble media protein that had passed through the 0.45μ filter (designated "filtrate") plus freeze-dried Saos-2 cells from which conditioned the culture medium was obtained. Results indicate that the bone-inducing agent of Saos-2 cells is not only retained by the cells, but is also secreted in both soluble and particulate forms into serum-free conditioned medium. Bone-inducing activity (per mg protein) is more concentrated in the particulate fraction, which is shown by electron microscopy to contain a mixture of vesicles (similar to matrix vesicles) plus electron dense granules (resembling ribosomes) and 10 mM microfilaments (of possible collagenous or cytoskeletal origin). BMP-1,2,3,4,6 and 7 were detected by western blots in both the soluble and particulate fractions of conditioned medium. Thus, it is indicated that Saos-2 cells secrete an osteoinductive factor which may function in vivo as a paracrine morphogenetic agent.

The article is about the tissue engineering research done in China. It discusses various aspects of tissue engineering in China including engineered bones, cartilage, skin, corneal stroma and blood vessels.

The article is about the tissue engineering laboratory in Malaysia. It touches on six areas of bioengineering, namely: skin, cartilage, bone, respiratory epithelium, stem cells and biomaterials.

AUSTRALIA – Australia's First Full Genome Project to be Conducted on Corals.

AUSTRALIA – Scientists May have Discovered New Potential Cure for Cancer.

AUSTRALIA – First Genetically-engineered Malaria Vaccine To Enter Human Trials.

CHINA – Lead Poisoning Sickens 600 Kids in China.

CHINA – Groundbreaking Treatment for Oxygen-deprived Newborns.

CHINA – China Builds First Heavy Ion Therapy Center for Cancer Patients.

CHINA – Creating Live Mice from Skin Cells.

INDIA – Human Clinical Trial in 2010 for Needle-free Measles Vaccination.

INDIA – Indian Wonder Herb can Treat Male Infertility.

JAPAN – Flood Resistant High-yield Rice Developed.

SINGAPORE – Minimally Invasive Option for Knee Cartilage Repair.

SINGAPORE – Novel Immunization Method for Malaria Offers Insights into Human Anti-Malaria Immune Response.

TAIWAN – Taiwan Researchers Identify Sites of Breast Cancer Genes.

TAIWAN – Taiwanese Researchers Develop Cell Therapy For Immunodeficiency.

TAIWAN – Remote Healthcare Services for High-risk Patients.

TAIWAN – Marine-derived Compounds Holds New Treatment Premise for Neuropathic Pain.

OTHER REGIONS — UNITED STATES – New No-needle Approach to Prevent Blood Clots.

Dysport vs. Botox: Coke vs Pepsi?

A New technique in Rhinoplasty: Diced Cartilage with Fascia.

What is New in Aesthetic Plastic Surgery?

The Role of Fractional Photothermolysis in Laser Skin Rejuvenation.

Chinese Maxillary Protusion Correction with Rhinoplasty.

The New Hip Thing: Flying halfway around the globe for a new hip.

Diagnostics & Cardiovascular Disease - Helping to Curtail Rising Numbers.

Frequent Monitoring of Atrial Fibrillation Patients and Anticoagulants.

Eco-friendlily Yours: The Way Forward.

TauRx enters collaborative R&D agreement with Bayer Schering Pharma.

Major New Asean Health and Well-Being Study.

The First Chinese Laboratory Recognized By International Olive Council (IOC).

China Kicks off Precision Medicine Research.

Chinese Researchers Find Flavonoids in Cotton Petals to Treat Alzheimer's Disease.

China Recognizes Prominent Scientists and Stresses on Innovation.

China Corporation Tencent in Kenya to Help Combat Illegal Wildlife Trade.

Catalyst Helps Convert Waste CO₂ into Fuel.

Articular Cartilage Stem Cells Participate in Cartilage Self-Repair during Early Osteoarthritis.

Chinese Scientists Develop Polygraph Based on AI Technology.

Scientists Uncover Beneficiary Effects of Dietary Iron Oxide Nanoparticles.

A New Water Robot “Born” to Detect Water Quality.

Archaeologists Discover World's Oldest Tea Buried with Ancient Chinese Emperor.

Scientists Find in situ KIT-expressing Cardiomyocytes.

Integrin CD11b Regulates Obesity-Related Insulin Resistance.

Asia's Medical Technology Start-ups Get New Fast Track to Market via Partnership between Cambridge Consultants and Clearbridge Accelerator

Mitsubishi Electric and Sembcorp Industries to Testbed Novel Ozone Backwashing Energy-Saving Membrane Bioreactor

LEO Pharma Enters Biologics through Strategic Partnership with AstraZeneca

Bayer and X-Chem Expand Drug Discovery Collaboration to Discover Novel Medicines

New Gas Chromatography System Brings Power of Orbitrap GC-MS Technology to Routine Applications

A*STAR and MSD Establish a New Research Collaboration to Advance Peptide Therapeutics

Stem Cells Engineered to Grow Cartilage, Fight Inflammation

Articular cartilage is a vital component of human knee joints by providing a low-friction and wear-resistant surface in knee joints and distributing stresses to tibia. The degeneration or damage of articular cartilage will incur acute pain on the human knee joints. Hence, to understand the mechanism of normal and pathological functions of articular cartilage, it is very important to investigate the contact mechanics of the human knee joints. Experimental research has difficulties in reproducing the physiological conditions of daily activities and measuring the key factors such as contact-stress distributions inside knee joint without violating the physiological environment. On the other hand, numerical approaches such as finite element (FE) analysis provide a powerful tool in the biomechanics study of the human knee joint. This article presents a two-dimensional (2D) FE model of the human knee joints that includes the femur, tibia, patella, quadriceps, patellar tendon, and cartilages. The model is analyzed with dynamic loadings to study stress distribution in the tibia and contact area during contact with or without articular cartilage. The results obtained in this article are very helpful to find the pathological mechanism of knee joint degeneration or damage, and thus guide the therapy of knee illness and artificial joint replacement.

Background. As articular cartilage is unable to repair itself, there is a tremendous clinical need for a tissue engineered replacement tissue. Current tissue engineering efforts using the self-assembly process have demonstrated promising results, but the biomechanical properties remain at roughly 50% of native tissue. Methodology/Principal Findings. The objective of this study was to determine the feasibility of using exogenous crosslinking agents to enhance the biomechanical properties of a scaffoldless cartilage tissue engineering approach. Four crosslinking agents (glutaraldehyde, ribose, genipin, and methylglyoxal) were applied each at a single concentration and single application time. It was determined that ribose application resulted in a significant 69% increase in Young's modulus, a significant 47% increase in ultimate tensile strength, as well as a trend toward a significant increase in aggregate modulus. Additionally, methylglyoxal application resulted in a significant 58% increase in Young's modulus. No treatments altered the biochemical content of the tissue. Conclusions/Significance. To our knowledge, this is the first study to examine the use of exogenous crosslinking agents on any tissue formed using a scaffoldless tissue engineering approach. In particular, this study demonstrates that a one-time treatment with crosslinking agents can be employed effectively to enhance the biomechanical properties of tissue engineered articular cartilage. The results are exciting, as they demonstrate the feasibility of using exogenous crosslinking agents to enhance the biomechanical properties without the need for increased glycosaminoglycan (GAG) and collagen content.

The purpose of this study was to investigate the attachment and proliferation of cells on selective laser-sintered (SLS) polycaprolactone (PCL) scaffolds coated with gelatin for cartilage tissue engineering using chondrocytes isolated from the articular cartilage of swine. Scaffolds without modification were used as control groups. Cell proliferation was measured by cell count 1, 3 and 5 days after cell seeding into the scaffolds. The biocompatibility of the scaffold was examined by scanning electron microscopy (SEM). The PCL scaffolds coated with gelatin had higher hydrophilicity. The results provided a useful strategy for modifying the microenvironments to increase cell attachment, growth and the formation of extracellular matrix on scaffolds for cartilage tissue engineering.