Purple urine bag syndrome in end-stage chronic kidney disease

Introduction: When faced with violet, purple or purplish-blue urine, clinicians should consider urinary tract infection in their differential diagnosis. Case report: A 60-year-old woman with end-stage kidney disease and non-adherence to renal replacement therapy was admitted to our hospital for placement of hemodialysis catheter. During her hospitalization she had purple urine, and purple urine bag syndrome (PUBS) was diagnosed. She was effectively treated with antibiotics and her urine returned to a dark yellow color. Discussion: Although this condition is often easily treated, diagnosing PUBS in chronic renal patients probably means an increased serum concentration of indoxyl sulfate, metabolite that is involved in the progression of both CKD and cardiovascular disease. Conclusion: Hence, in the context of our renal patients, perhaps PUBS is not as benign as supposed. .

The metabolic dynamics of cartilage explants over a long-term culture period

INTRODUCTION: Although previous studies have been performed on cartilage explant cultures, the generalized dynamics of cartilage metabolism after extraction from the host are still poorly understood due to differences in the experimental setups across studies, which in turn prevent building a complete picture. METHODS: In this study, we investigated the response of cartilage to the trauma sustained during extraction and determined the time needed for the cartilage to stabilize. Explants were extracted aseptically from bovine metacarpal-phalangeal joints and cultured for up to 17 days. RESULTS: The cell viability, cell number, proteoglycan content, and collagen content of the harvested explants were analyzed at 0, 2, 10, and 17 days after explantation. A high percentage of the cartilage explants were found to be viable. The cell density initially increased significantly but stabilized after two days. The proteoglycan content decreased gradually over time, but it did not decrease to a significant level due to leakage through the distorted peripheral collagen network and into the bathing medium. The collagen content remained stable for most of the culture period until it dropped abruptly on day 17. CONCLUSION: Overall, the tested cartilage explants were sustainable over long-term culture. They were most stable from day 2 to day 10. The degradation of the collagen on day 17 did not reach diseased levels, but it indicated the potential of the cultures to develop into degenerated cartilage. These findings have implications for the application of cartilage explants in pathophysiological fields.

Fibrin glue increases the cell survival and the transduced gene product secretion of the ceiling culture-derived adipocytes transplanted in mice

The development of clinically applicable scaffolds is important for the application of cell transplantation in various human diseases. The aims of this study are to evaluate fibrin glue in a novel protein replacement therapy using proliferative adipocytes and to develop a mouse model system to monitor the delivery of the transgene product into the blood and the fate of the transduced cells after transplantation. Proliferative adipocytes from mouse adipose tissue were transduced by a retroviral vector harboring the human lecithin-cholesterol acyltransferase (lcat) gene, and were subcutaneously transplanted into mice combined with fibrin glue. The lcat gene transduction efficiency and the subsequent secretion of the product in mouse adipocytes were enhanced using a protamine concentration of 500 microg/ml. Adipogenesis induction did not significantly affect the lcat gene-transduced cell survival after transplantation. Immunohistochemistry showed the ectopic enzyme production to persist for 28 days in the subcutaneously transplanted gene-transduced adipocytes. The increased viability of transplanted cells with fibrin glue was accompanied with the decrease in apoptotic cell death. The immunodetectable serum LCAT levels in mice implanted with the fibrin glue were comparable with those observed in mice implanted with Matrigel, indicating that the transplanted lcat gene-transduced adipocytes survived and functioned in the transplanted spaces with fibrin glue as well as with Matrigel for 28 days. Thus, this in vivo system using fibrin is expected to serve as a good model to further improve the transplanted cell/scaffold conditions for the stable and durable cell-based replacement of defective proteins in patients with LCAT deficiency.

Effect of hydrostatic pressure of various magnitudes on osteoarthritic chondrocytes exposed to IL-1β.

Background & objectives: Several in vitro studies have shown the importance of mechanical compression or hydrostatic pressure (HP) as a modulator of cartilage metabolism. The present study was undertaken to evaluate the in vitro effects of cyclical low HP (1-5 MPa) and continuous high HP (24 MPa) applied in the presence or absence of interleukin (IL)-1β on human osteoarthritis (OA) chondrocytes. Methods: Chondrocytes obtained from OA cartilage were cultivated for 48 h and then exposed to pressurization in the presence or absence of IL-1β. After pressurization, the culture medium was collected to detect the amount of proteoglycans (PG) and nitric oxide (NO) and the chondrocytes were immediately fixed for transmission electron microscopy (TEM) and processed for immunocytochemistry to localize the inducible nitric oxide synthase (iNOS). Results: A significant increase in the level of PG and a small, non-significant, decrease in NO production were observed upon exposure to cyclical low HP. On the other hand, exposure to continuous high HP resulted in a significant decrease in the PG levels and a significant increase in NO production. The presence of IL-1β led to a significant decrease in PG levels as well as a significant increase in NO production. The cyclical low HP did not increase the PG levels significantly but caused a statistically significant decrease in NO production in cultures damaged with IL-1β. The continuous high HP in chondrocyte cultures stimulated with IL-1β did not significantly decrease PG production, but significantly increased NO production. The results concerning metabolic production were further confirmed by morphological findings obtained by TEM and immunocytochemical studies. Interpretation & conclusion: The findings of this study confirmed that the response of chondrocytes varies with magnitude and frequency of HP. These findings are important to understand aetiopathogenetic mechanisms of OA and to find out which type of physical activity may be best suited for the prevention and therapy of OA.

2-Deoxy-D-glucose regulates dedifferentiation through beta-catenin pathway in rabbit articular chondrocytes

2-deoxy-D-glucose (2DG) is known as a synthetic inhibitor of glucose. 2DG regulates various cellular responses including proliferation, apoptosis and differentiation by regulation of glucose metabolism in cancer cells. However, the effects of 2DG in normal cells, including chondrocytes, are not clear yet. We examined the effects of 2DG on dedifferentiation with a focus on the beta-catenin pathway in rabbit articular chondrocytes. The rabbit articular chondrocytes were treated with 5 mM 2DG for the indicated time periods or with various concentrations of 2DG for 24 h, and the expression of type II collagen, c-jun and beta-catenin was determined by Western blot, RT-PCR, immunofluorescence staining and immunohistochemical staining and reduction of sulfated proteoglycan synthesis detected by Alcain blue staining. Luciferase assay using a TCF (T cell factor)/LEF (lymphoid enhancer factor) reporter construct was used to demonstrate the transcriptional activity of beta-catenin. We found that 2DG treatment caused a decrease of type II collagen expression. 2DG induced dedifferentiation was dependent on activation of beta-catenin, as the 2DG stimulated accumulation of beta-catenin, which is characterized by translocation of beta-catenin into the nucleus determined by immunofluorescence staining and luciferase assay. Inhibition of beta-catenin degradation by inhibition of glycogen synthase kinase 3-beta with lithium chloride (LiCl) or inhibition of proteasome with z-Leu-Leu-Leu-CHO (MG132) accelerated the decrease of type II collagen expression in the chondrocytes. 2DG regulated the post-translational level of beta-catenin whereas the transcriptional level of beta-catenin was not altered. These results collectively showed that 2DG regulates dedifferentiation via beta-catenin pathway in rabbit articular chondrocytes.

Stemness Evaluation of Mesenchymal Stem Cells from Placentas According to Developmental Stage: Comparison to Those from Adult Bone Marrow

This study was done to evaluate the stemness of human mesenchymal stem cells (hMSCs) derived from placenta according to the development stage and to compare the results to those from adult bone marrow (BM). Based on the source of hMSCs, three groups were defined: group I included term placentas, group II included first-trimester placentas, and group III included adult BM samples. The stemness was evaluated by the proliferation capacity, immunophenotypic expression, mesoderm differentiation, expression of pluripotency markers including telomerase activity. The cumulative population doubling, indicating the proliferation capacity, was significantly higher in group II (P<0.001, 31.7+/-5.8 vs. 15.7+/-6.2 with group I, 9.2+/-4.9 with group III). The pattern of immunophenotypic expression and mesoderm differentiation into adipocytes and osteocytes were similar in all three groups. The expression of pluripotency markers including ALP, SSEA-4, TRA-1-60, TRA-1-81, Oct-4, and telomerase were strongly positive in group II, but very faint positive in the other groups. In conclusions, hMSCs from placentas have different characteristics according to their developmental stage and express mesenchymal stemness potentials similar to those from adult human BMs.

Análise fotocolorimétrica computadorizada dos efeitos da betametasona intra-articular sobre a concentração de proteoglicanos da matriz cartilaginosa de joelhos leporinos: influência do número de injeções intra-articulares / Computerized photocolorimetric analysis of the effects of intraarticular betamethasone on the proteoglycan concentration of leporine knee cartilage matrix: influence of the number of intraarticular injections

OBJETIVO: Analisar os efeitos da injeção repetida de betametasona na concentração de proteoglicanos da cartilagem articular do joelhos normais de coelhos californianos de ambos os sexos. MÉTODOS: Os animais foram randomizados em oito grupos de dez animais cada. Três grupos controle (injeção ou não de solução salina isotônica) e cinco grupos de estudo - doses terapêuticas, repetidas ou não, de betametasona injetadas no joelho direito de cada coelho, com intervalos semanais. Após oito dias da última injeção prevista, cortes histológicos da cartilagem das áreas de apoio dos platôs tibiais foram corados com hematoxilina e eosina para análise por microscopia óptica, e com safranina O para a pesquisa da quantidade de proteoglicanos. A intensidade da coloração da safranina O foi quantificada em aparelho de histomorfometria, composto por microscópio Olympus BX 50 e microcomputador com software Image Pro-plus 4.5Ò. RESULTADOS: Não houve diferenças nos animais que tiveram seus joelhos injetados com betametasona uma, duas e quatro vezes quando comparados com os grupos controle. Nos animais que receberam seis e oito aplicações a intensidade da coloração com safranina O reduziu-se significativamente (p < 0,05) quando comparada tanto com grupos controle quanto com os outros de estudo. CONCLUSÃO: Foi possível demonstrar redução da concentração de proteoglicanos na matriz cartilaginosa articular dependente do efeito deletério cumulativo das repetidas injeções intra-articulares de betametasona.

OBJECTIVE: To study the effects of repeated injections of betamethasone on proteoglycan concentration in the articular cartilage of normal knees of Californian rabbits of both sexes. METHODS: Eighty animals were randomly divided into eight groups of ten animals each. Three control groups (saline solution injected or not) and five study groups - therapeutical doses, repeated or not, of betamethasone injected into the right knee of each animal at weekly intervals. After eight days from the last injection, sections of articular cartilage from tibial plateaus collected from weight-bearing surfaces were stained with hematoxylin and eosin for light microscopy analysis and with safranin O for the proteoglycan content assay. The staining intensity of safranin O was quantified by histomorphometry using an Olympus BX 50 microscope and a microcomputer with the Image Pro-plus 4.5Ò software. RESULTS: Animals receiving one, two and four betamethasone injections showed no differences when compared to normal controls. Animals receiving six and eight injections had a significant decrease in safranin O staining intensity (p < 0.05) as compared to the control groups and the other study groups. CONCLUSION: A decrease in the concentration of articular cartilage proteoglycans dependent on repeated betamethasone injection was effectively demonstrated.

Avaliação do metabolismo celular decorrente da aplicação de força nos condrócitos do côndilo mandibular e do joelho de suínos / Comparison of in vitro desponse to mechanical loading between the porcine mandibular condyle and ankle articular cartilages

Funcionalmente, a cartilagem da articulação têmporo-mandibular assemelha-se à cartilagem da articulação do joelho por possuírem lubrificação para resistir à fricção e fornecerem proteção às forças mecânicas externas. Entretanto, o efeito das forças de tensão sobre as cartilagens dessas duas articulações ainda permanece obscura. O objetivo desse estudo foi avaliar, in vitro, as alterações metabólicas nos condrócitos extraídos do tecido cartilaginoso do côndilo mandibular e do joelho de suínos, decorrentes da aplicação de forças mecânicas, em relação à síntese de DNA e de proteoglicanos (PTG). Além disso, foi verificada a expressão de colágeno tipo II e de agrecanos no RNAm dos condrócitos dessas duas articulações, tempo-dependente do cultivo celular, utilizando-se a análise quantitativa de PCR em tempo real. Os condrócitos foram submetidos às forças mecânicas de tração de 2 kPa (3 porcento de alongamento), 5 kPa (7 porcento de alongamento) e 10 kPa (12 porcento de alongamento), em uma freqüência de 30 ciclos/min. durante 12 e 24 horas. Os resultados demonstraram que os condrócitos do côndilo mandibular quando submetidos às forças de 2 kPa e de 5 kPa, apresentaram um aumento estatisticamente significativo da síntese de DNA e de PTG, em 12 h. (p < 0,01) e em 24 h. (p < 0,05). Exceto o aumento da síntese de DNA do grupo submetido à força de 5 kPa que durante 24h. não foi estatisticamente significativo (p > 0,05). A força de 10 kPa causou uma diminuição estatisticamente significativa na síntese de DNA e de PTG nos condrócitos do côndilo mandibular, em ambos os tempos de ensaio mecânico (p < 0,01). Por outro lado, os condrócitos do joelho apresentaram um aumento na síntese de DNA e de PTG quando submetidos à todas as magnitudes de força de tração...

Functionally, the mandibular condylar cartilage is similar to the ankle articular cartilage, both provides lubrication to resist friction and offers protection against external mechanical loading. However, the effect of tension loadings on these two articular cartilages remains unclear. The purpose of this study was to evaluate in vitro, the metabolism of the chondrocytes isolated from the cartilage tissues of porcine mandibular condyle and ankle, in response to the tension mechanical forces, related to the syntheses of DNA and proteoglycan (PTG). It was also verified the expression of mRNA type II collagen and aggrecan on the condrocytes of these two joints on culture time-dependent, using a quantitative real-time PCR analysis. The chondrocytes were submitted to tensile mechanical strains of 2 kPa (3 percent elongation), 5 kPa (7 percent elongation) and 10 kPa (12 percent elongation), with a frequency of 30 cycles/min for 12 and 24 hours. The results showed that the condrocytes from mandibular condyle, when submitted to tension forces of 2 kPa and 5 kPa, demonstrated a statistically significant enhancement of DNA and PTG, in 12 h. (p < 0.01) and in 24 h. (p < 0.05). Except the increase of DNA synthesis of the group submitted to the force of 5 kPa during 24 h. that was not statistically significant (p > 0.05). The force of 10 kPa caused a statistically significant decrease of DNA and PTG syntheses on the condrocytes of mandibular condyle, in both periods of mechanical stimulation (p < 0.01). On the other side, the condrocytes of ankle showed an increase of DNA and PTG syntheses when subjected to all the magnitudes of tension forces...

Overexpression of Transforming Growth Factor-beta1 in the Valvular Fibrosis of Chronic Rheumatic Heart Disease

For the purpose of determining the pathogenic role of transforming growth factor-beta1 (TGF-beta1) in the mechanism of chronic rheumatic heart disease, we evaluated the expression of TGF-beta1, proliferation of myofibroblasts, and changes in extracellular matrix components including collagen and proteoglycan in 30 rheumatic mitral valves and in 15 control valves. High TGF-beta1 expression was identified in 21 cases (70%) of rheumatic mitral valves, whereas only 3 cases (20%) of the control group showed high TGF-beta1 expression (p<0.001). Additionally, increased proliferation of myofibroblasts was observed in the rheumatic valves. High TGF-beta1 expression positively correlated with the proliferation of myofibroblasts (p=0.004), valvular fibrosis (p< 0.001), inflammatory cell infiltration (p=0.004), neovascularization (p=0.007), and calcification (p<0.001) in the valvular leaflets. The ratio of proteoglycan to collagen deposition inversely correlated with TGF-beta1 expression in mitral valves (p=0.040). In conclusion, an ongoing inflammatory process, the expression of TGF-beta1, and proliferation of myofibroblasts within the valves have a potential role in the valvular fibrosis, calcification, and changes in the extracellular matrix that lead to the scarring sequelae of rheumatic heart disease.

Chondroprotective potential of root extracts of Withania somnifera in osteoarthritis.

This is the first report describing two novel chondroprotective activities of aqueous extracts of Withania somnifera root powder.First,these extracts had a statistically significant,short-term chondroprotective effect on damaged human osteoarthritic cartilage matrix in 50% of the patients tested. Second,these extracts caused a significant and reproducible inhibition of the gelatinase activity of collagenase type 2 enzyme in vitro.

Indigo Carmine for the Selective Endoscopic Intervertebral Nuclectomy

This study was undertaken to prove that the selectively infiltrated parts of nucleus pulposus with indigo carmine was degenerated parts of nucleus pulposus. This study was done, between August and October 2002, in 5 patients, who received endoscopic discectomy, due to intervertebral disc herniation. Discogram was done with mixture of indigo carmine and radioactive dye. Blue discolored part was removed through endoscope, and small undiscolored part was removed together for the control. The two parts were stained with hematoxylin and eosin and compared under the microscope. Undiscolored part was normal nucleus pulposus, composed of chondrocytes with a matrix of type II collagen and proteoglycan, mainly aggrecan. However, in discolored part, slits with destruction of collagen fiber array and ingrowth of vessel and nerve were observed. Using indigo carmine in endoscopic discectomy gives us selective removal of degenerated disc.

Proteoglycans production by aortic vascular smooth muscle cells from hypertensive rats

Remodeling of large and small arteries contributes to the development and complications of hypertension. Artery structural changes in chronic sustained hypertension include vascular smooth muscle cells (VSMC) proliferation and extracellular matrix (ECM) modifications. Extracellular constituents such as proteoglycans (PGs), may modulate vascular stiffness and VSMC growth and differentiation. We examined the effect of growth factors on secreted and membrane-bound PGs synthesis by cultured aortic smooth muscle cells (SMC) from 12- to 14- week-old spontaneously hypertensive rats (SHR) and age-matched Wistar rats. After stimulation with platelet-derived growth factor (PDGF-BB), 10% fetal calf serum (FCS) or 0.1% FCS as control, PGs synthesis (dpm/ng DNA) was evaluated in the medium (M-ECM) and in the cell layer (P-ECM) by a double-isotopic label method using both [3H]-glucosamine and [35S]-sodium sulfate which are incorporated into all complex carbohydrates or only into sulfated dysaccharides, respectively. Data are presented as percent of the control (0.1% FCS). SHR VSMC displayed a significantly greater synthesis of M-ECM [3H]-PGs than Wistar rat cells, with both treatments, but no differences in M-ECM [35S] uptake were found in any case. In the P-ECM, both PDGF-BB and 10% FCS produced a greater effect on [3H]-PGs and sulfated PGs synthesis in VSMC from SHR. An important change seen in SHR cells was a significant decreased sulfation, assessed by [35S]/[3H] ratio, in basal and stimulation conditions. Present results indicate the existence of changes in PGS synthesis and modulation in VSMC from a conduit-artery of SHR and support the pathophysiological role proposed for matrix proteoglycans in the vascular wall changes associated to hypertension and related vascular diseases as atherosclerosis.

The extracellular matrix in multiple sclerosis: an update

Extracellular matrix (ECM) molecules play important roles in the pathobiology of the major human central nervous system (CNS) inflammatory/demyelinating disease multiple sclerosis (MS). This mini-review highlights some recent work on CNS endothelial cell interactions with vascular basement membrane ECM as part of the cellular immune response, and roles for white matter ECM molecules in demyelination and remyelination in MS lesions. Recent basic and clinical investigations of MS emphasize axonal injury, not only in chronic MS plaques, but also in acute lesions; progressive axonal degeneration in normal-appearing white matter also may contribute to brain and spinal cord atrophy in MS patients. Remodeling of the interstitial white matter ECM molecules that affect axon regeneration, however, is incompletely characterized. Our ongoing immunohistochemical studies demonstrate enhanced ECM versican, a neurite and axon growth-inhibiting white matter ECM proteoglycan, and dermatan sulfate proteoglycans at the edges of inflammatory MS lesions. This suggests that enhanced proteoglycan deposition in the ECM and axonal growth inhibition may occur early and are involved in expansion of active lesions. Decreased ECM proteoglycans and their phagocytosis by macrophages along with myelin in plaque centers imply that there is "injury" to the ECM itself. These results indicate that white matter ECM proteoglycan alterations are integral to MS pathology at all disease stages and that they contribute to a CNS ECM that is inhospitable to axon regrowth/regeneration

Predisposicion a la oxidacion in vitro de la LDL aislada de pacientes con hipercolesterolemia. Interaccion con proteoglicanos arteriales / Predisposition to in vitro oxidation of LDL isolated from hypercholesterolemic patients. Interaction with arterial proteoglycans

Se ha demostrado que existe una correlación positiva entre la ateroesclerosis y los niveles elevados de colesterol plasmático. Estudios recientes han permitido estabelecer nuevos factores que podrían estar involucrados en el proceso aterogénico como sería la oxidación de los ácidos grasos poliinsaturados presentes en la estructura de la lipoproteina de baja densidad (LDL) que las haría potencialmente más aterogénicas. Paralelamente, hay evidencias que indican que la interacción de la LDL con componentes de la matriz extracelular de la íntima arterial, específicamente con proteoglicanos, podría contribuir a la acumulación de esta lipoproteina durante el proceso aterogénico. En el presente trabajo se exploró la susceptibilidad a la oxidación de la LDL aislada de pacientes hipercolesterolémicos y los resultados obtenidos sugieren que esta lipoproteina tiene mayor predisposición a la oxidación y además estas LDL mostraron una mayor afinidad por proteoglicanos arteriales aislados de íntima-media de aorta humana.

Is there a relationship between the state of aggregation os small proteoglycans and the biomechanical properties of tissues?

The small proteoglycans fibromodulin and decorin may play an important role in regulating collagen fibrillogenesis and interactions with growth factors. Here, we describe the presence of these proteoglycans in cartilage submitted to different biomechanical forces. Fibromodulin from chicken and bovine articular cartilage was shown to self-associate. The different states of fibromodulin aggregation due to disulfide bonding demonstrable in different regions of the same joint suggest that the presence of different biomechanical forces results in the differential expression of small proteoglycans. A 250-kDa complex found in chicken tibiotarsal cartilage, which migrates as a 59-kDa component in SDS-PAGE under reducing conditions, and which was recognized by anti-fibromodulin antibodies, was not demonstrable in tarsometatarsal cartilage where a different fibromodulin complex has been recently demonstrated. Biglycan and decorin were not expressed in the same way in different regions of the bovine knee joint, suggesting that there is a relationship between the expression of small proteoglycans and the different biomechanical properties of a tissue.

Effect of moderate & high loadings on the proteoglycans & water content of bovine knee joint articular cartilage.

Variations in proteoglycans and water content of the knee joint cartilage were found to occur when the joint was subjected to articulating motion under moderate and high loadings. It was found that at a moderate load of 150 kg there were an increase in the percentage of proteoglycans but the percentage decreased when the joint was articulated at a high loading of 300 kg. It has also been observed that the ratio of water content and the proteoglycans decreased at moderate load, whereas the ratio increased at high load. The observed changes in proteoglycans and water content in extracellular matrix with moderate and high loadings suggested that articular cartilage properties respond to mechanical stresses.

Myelopoietic competence of stroma composed of hepatic granuloma-derived connective tissue cells or skin fibroblasts

1. Connective tissue cells isolated form hepatic granulomas (GR cells), induced in mouse liver tissue by schistosomal infection, are able to sustain myelopoiesis, while other connective tissue cells such as skin fibroblasts (SF) are not. 2. We compared the ability of SF and GR cells sustain in vitro proliferation of the FDC-P1 myeloid cell line, dependent upon IL-3 or GM-CSF. 3. Only the GR stroma susteined the proliferation of co-cultured FDC-P1 cells. RT-PCR analysis showed that both cell lines expressed the message for GM-CSF, but not for IL-3. We showed that GM-CSF was produced by, and remained bound to the cell layer through heparan sulfate; this growth factor could be released by high-salt treatment in a biologically active form from both cell types. The same activity could be restored to NaCl-treated GR cells, but not to SF, by incubation with recombinant murine GM-CSF. 4. These results indicate that the ability of connective tissue cells to sustain myelopoiesis depends directly upon the capapcity of their heparan sulfate-bearing molecules to bind and present the GM-CSF to the target cells in a biologically active form. Alternatively, a yet unidentified set of cell layer-associated molecules may be required for the positive or negative control of the membrane-bound GM-CSF

Effect of total food deprivation on the proteoglycans of rat hyaline cartilage and bone

Hay hipótesis que sugieren que el efecto de la privación total de alimentos sobre el hueso ocurre por alteraciones en la síntesis de la matriz orgánica. Este trabajo se llevó a cabo con el propósito de caracterizar las posibles alteraciones en las propiedades de los proteoglucanos de cartílago hialino y hueso de rata como resultado de un ayuno total. Ratas macho de la cepa Wistar fueron separadas aleatoriamente y asignadas a un grupo control que comió y bebió "ad libitum" o a un grupo experimental que únicamente bebió agua. Los animales fueron pesados y sacrificados a los 4 u 8 días de iniciada la experiencia después de administrarles una dosis de 35S(-SO4-). Se aislaron los PG de los fémures y cartílagos xifoides y se determinó la captación de 35S, el patrón de distribución de los GAG, el peso molecular y densidad de los PG y el largo de las cadenas laterales. Todos los parámetros analizados disminuyeron significativamente después de 4 y 8 días mostró una disminución de la fracción correspondiente al Congroitin-4-Sulfato. Estos resultados podrían indicar una alteración en el proceso de osificación como consecuencia de las modificaciones en las propiedades de los PG que alterarían su unión con el colágeno, molécula que desempeña un papel muy importante en el mencionado proceso