Chondrogenic potential of subpopulations of cells expressing mesenchymal stem cell markers derived from human synovial membranes.

In this study we analyzed the chondrogenic potential of subpopulations of mesenchymal stem cells (MSCs) derived from human synovial membranes enriched for CD73, CD106, and CD271 markers. Subpopulations of human synovial membrane MSCs enriched for CD73, CD106, and CD271 markers were isolated using a cytometry sorter and characterized by flow cytometry for MSC markers. The expression of Sox9, Nanog, and Runx2 genes by these cells was measured by reverse transcriptase-polymerase chain reaction. The chondrogenesis of each subpopulation was assessed by culturing the cells in a defined medium to produce spontaneous spheroid formation and differentiation towards chondrocyte-like cells. The examination of the spheroids by histological and immunohistochemical analyses for collagen type II (COL2), aggrecan, collagen type I (COL1), metalloprotease 13 (MMP13), and collagen type X (COLX) levels were performed to assess their chondrogenesis capacity. The adipogenesis and osteogenesis potential of each subpopulation was determined using commercial media; the resulting cells were stained with oil red O or red alizarin to test the degree of differentiation. The subpopulations had different profiles of cells positive for the MSC markers CD44, CD69, CD73, CD90, and CD105 and showed different expression levels of the genes Sox9, Nanog, and Runx2 involved in chondrogenesis, undifferentiation, and osteoblastogenesis, respectively. Immunohistochemical analysis demonstrated that COL1, COL2, COLX, MMP13, and aggrecan were expressed in the spheroids as soon as 14 days of culture. The CD271(+) subpopulation expressed the highest levels of COL2 staining compared to the other subpopulations. CD105 and Runx2 were shown by immunohistochemistry and genetic analysis to have significantly higher expression CD271(+) subpopulation than the other subpopulations. Spheroids formed from CD271-enriched and CD73-enriched MSCs from normal human synovial membranes mimic the native cartilage extracellular matrix more closely than CD106(+) MSCs and are possible candidates for use in cartilage tissue engineering. Both cell types have potential for promoting the differentiation of MSCs into chondrocytes, presenting new possibilities for achieving intrinsic cartilage repair.

Ambient conditions of elevated temperature and CO2 levels are detrimental to the probabilities of transmission by insects of a Potato virus Y isolate and to its simulated prevalence in the environment.

Conditions of elevated temperature and CO2 levels [30 °C and 970 parts-per-million (ppm), respectively] reduced the systemic titers of a potato virus Y (PVY) isolate in Nicotiana benthamiana plants, relative to standard conditions (25 °C, ~405 ppm CO2). Under controlled conditions we studied how these growing environments affected the transmission of infection by aphids. Probabilities of transmission of infection by insects that fed on infected donor plants kept at either standard conditions, or at 30 °C and 970 ppm CO2 were both determined and found to positively correlate with titers in donor leaves, independently of the ambient conditions in which recipient plantlets would grow. With these data, viral prevalence was simulated under conditions of elevated temperature and CO2 levels and found that for it to remain comparable to that simulated under standard conditions, insect arrivals to recipient plants in the former scenario would have to increase several-fold in their frequency.

Increasing resolution of airborne pollen forecasting at a discrete sampled area in the southwest Mediterranean Basin.

Daily fluctuations of the airborne pollen concentrations produce variations on symptomatology in allergic population. Such fluctuations are influenced by local vegetal coverage, flowering phenology, geography and climatology. Since 1991, airborne pollen of Malaga province (southern Spain) has been monitored in 7 different locations. Malaga station has been kept operational uninterruptedly throughout the studied period, while the rest of the stations only worked in periods of 2-4 years. Weekly, its pollen information is updated online to inform the population in order to prevent allergic diseases. Increasing the spatial resolution of pollen information would be very useful for allergic population living at unsampled locations. Due to the impossibility of keeping operational a high number of pollen stations covering the whole province of Malaga, the aim of this study is to create spatial models to extrapolate and forecast the pollen concentrations to Malaga province by using the concentrations registered at the capital as unique input. To do so, the relationships obtained between the airborne pollen concentrations detected at Malaga city and those detected at the other stations have been used to elaborate models for the main pollen types registered at the province. These models were spatially interpolated all over the province by using co-kriging techniques and the Compensated Thermicity Index as covariable. As result of this work, pollen distribution of the 8 most prevalent taxa has been depicted all over the whole Malaga province and an allergy alert system has been set up to extrapolate pollen information from Malaga to the whole province.

Automatic Paroxysmal Atrial Fibrillation Based on not Fibrillating ECGs.

OBJECTIVES: The objective of the paper is to describe an automatic algorithm for Paroxysmal Atrial Fibrillation (PAF) Detection, based on parameters extracted from ECG traces with no atrial fibrillation episode. The modular automatic classification algorithm for PAF diagnosis is developed and evaluated with different parameter configurations. METHODS: The database used in this study was provided by Physiobank for The Computers in Cardiology Challenge 2001. Each ECG file in this database was translated into a 48 parameter vector. The modular classification algorithm used for PAF diagnosis was based on the nearest K-neighbours. Several configuration options were evaluated to optimize the classification performance. RESULTS: Different configurations of the proposed modular classification algorithm were tested. The uni-parametric approach achieved a top classification rate value of 76%. A multi-parametric approach was configured using the 5 parameters with highest discrimination power, and a top classification rate of 80% was achieved; different functions to typify the parameters were tested. Finally, two automatic parametric scanning strategies, Forward and Backward methods, were adopted. The results obtained with these approaches achieved a top classification rate of 92%. CONCLUSIONS: A modular classification algorithm based on the nearest K-neighbours was designed. The classification performance of the algorithm was evaluated using different parameter configurations, typification functions and number of K-neighbors. The automatic parametric scanning techniques achieved much better results than previously tested configurations.

ECG characterization of paroxysmal atrial fibrillation: parameter extraction and automatic diagnosis algorithm.

Paroxysmal atrial fibrillation (PAF) is one of the most common heart arrhythmias. It is very difficult to detect unless an explicit Atrial Fibrillation episode occurs during the exploration. The present paper describes a number of low level parameters extracted from ECG traces where no Atrial Fibrillation process is present. The ability of this parameter set to characterize PAF patients is studied and discussed. Based on these parameters a modular automatic classification algorithm for PAF diagnosis is developed and evaluated.

[The bone manifestations in 94 cases of sarcoidosis]. / Manifestaciones óseas de 94 casos de sarcoidosis.

94 patients diagnosed as having sarcoidosis were studied in Galicia in order to evaluate the frequency of bone manifestations, as well as to analyse the clinical and radiological features. Bone lesions were found in 10 patients (10.6%) with a median age of 47.4 years, the predominant sex being female in this group (70%). The lesions were of two types: a) osteolytic on metacarpal (4 cases), nasal bones (1 case), sacrum (1 case), femur (1 case); b) osteosclerosis on femur and fibula (1 case), acrosclerosis (3 cases), metacarpal (1 case). The first lesions were associated to chronic types of sarcoidosis with skin and lung involvements. The second lesions were associated to a sub-acute type of Löfgren. We highlight the behaviour of both types of bone lesions and comment on the physiopathology of the sclerotic lesions.

Bone tumors of mixed origin: osteo-liposarcoma and osteo-rhabdomyosarcoma.

1. A complete perusal of the literature revealed twenty cases of primary liposarcoma of bone acceptable as such to the authors. These were tabulated as to location and age. 2. Eight cases of osteo-liposarcoma, primary in bone, were encountered in the literature and an additional case was reported by the authors. 3. The authors described for the first time in the literature a new primary tumor of bone of mixed origin: osteo-rhabdomyosarcoma. After careful perusal of the literature they added three additional cases: two cases, previously reported as primary rhabdomyosarcoma of bone, which on careful evaluation of the radiographs in said publications and the paucity of microphotographs they considered to be osteo-rhabdomyosarcomas, and the other case, previously reported as malignant mesenchymoma of the sternum following radiotherapy for breast cancer. 4. The authors prefer to classify these tumors (osteo-liposarcoma and osteo-rhabdomyosarcoma) as "Tumors of Mixed Origin" and not as "Malignant Mesenchymomas". 5. A complete review of the literature revealed 219 reported "dedifferentiated" chondrosarcomas, or chondrosarcomas "with additional mesenchymal component", among which only nine (9) contained a bona fide rhabdomyosarcomatous component. The rest exhibited other mesenchymal tumors as osteogenic sarcoma, fibrosarcoma, malignant fibrous histiocytoma, angiosarcoma, and undifferentiated sarcoma. The authors recommend to continue classifying these tumors as chondrosarcomas with additional mesenchymal component or even as "dedifferentiated" chondrosarcomas but not as malignant mesenchymomas.

Osteoarthritis chondrocytes die by apoptosis. A possible pathway for osteoarthritis pathology.

OBJECTIVE: To determine which kind of cell death occurs in cartilage from patients with osteoarthritis (OA). METHODS: Seven normal and 16 OA cartilage samples were collected at autopsy or during joint replacement surgery, respectively. A piece of cartilage was cryopreserved until histologic studies were done. The rest of the cartilage was used to isolate chondrocytes. Apoptotic chondrocytes were analyzed by light and fluorescence microscopy using nuclear 4',6-diamidino-2-phenylindole dihydrochloride stain. Apoptotic chondrocytes were quantified by fluorescence-activated cell sorter (FACS) analysis. The TUNEL technique was used to study histologic apoptosis in situ. Superficial cartilage was processed for ultrastructural study by electron microscopy. RESULTS: OA chondrocytes displayed nuclear and cytoplasmic changes consistent with apoptotic cell death. FACS analysis showed that the OA cartilage had a higher proportion of apoptotic chondrocytes than did normal tissue (51% versus 11%; P < 0.01). In situ study of DNA fragmentation in the cartilage showed that apoptotic cells were located in the superficial and middle zones. Ultrastructural analysis of the superficial OA cartilage revealed some empty lacunae, lysosomal-like structures, matrix vesicle-like structures, fragmented chondrocytes, and nuclear condensation. CONCLUSION: Chondrocytes in OA cartilage demonstrated morphologic changes that are characteristic features of apoptosis. This mechanism of cell death plays an important role in the pathogenesis of OA and could be targeted for new treatment strategies.

Effect of antiinflammatory drugs on COX-1 and COX-2 activity in human articular chondrocytes.

OBJECTIVE: To study the effect of steroidal and nonsteroidal antiinflammatory drugs (NSAID) on cyclooxygenase (COX-1 and COX-2) activity in human articular chondrocytes. METHODS: Chondrocytes were isolated from articular cartilage of donors with no articular disease. Unstimulated and interleukin 1 (IL-1) stimulated chondrocytes were used as models to study the effects of drugs on COX-1 and COX-2. Cells were incubated with vehicle or drugs; supernatants were removed and the level of prostaglandin E2 (PGE2) in each sample was determined by enzyme immunoassay. IC50 were calculated from the reduction in PGE2 content by different concentrations of the test substance by linear regression analysis. RESULTS: COX- mRNA was detected in unstimulated cells, but stimulation with IL-1 for up 12 h did not modify the levels of COX-1 mRNA. In contrast, COX-2 mRNA was not detectable in unstimulated cells, but it was induced by IL-1. Dexamethasone inhibited COX-2 mRNA expression induced by IL-1. COX-2 protein levels correlated with mRNA expression. Dexamethasone was the strongest drug inhibitor of COX-2 (IC50 = 0.0073 microM). However, it did not inhibit COX-1 activity. Among all NSAID tested, meloxicam and aspirin were the least potent inhibitors of COX-1 (IC50 = 36.6 microM and 3.57 microM, respectively). Indomethacin and diclofenac were the most potent inhibitors of COX-1 (IC50 = 0.063 microM and 0.611 microM, respectively) and COX-2 isoforms (IC50 = 0.48 microM and IC50 = 0.63 microM, respectively). Meloxicam was a more potent inhibitor of COX-2 (IC50 = 4.7 microM) than aspirin (IC50 = 29.3 microM) and similar to piroxicam (IC50 = 4.4 microM). Among all drugs tested dexamethasone showed the greatest selectivity for COX-2 and meloxicam was the NSAID with the best COX-2/COX-1 ratio (r = 0.12). Aspirin and piroxicam were about 8 times more active against COX-1 than COX-2, indomethacin was 7 times more active, and diclofenac was an equipotent inhibitor of COX-1 and COX-2. CONCLUSION: We found that COX-1 and COX-2 isoforms are expressed in human chondrocytes at rest and in IL-1 stimulated cells, respectively. Antiinflammatory drugs have different capacities to inhibit COX enzyme in human articular chondrocytes.

Pollinosis due to Australian pine (Casuarina): an aerobiologic and clinical study in southern Spain.

An aerobiologic and clinical survey was conducted in Málaga, southern Spain, in order to determine fluctuations of Australian pine (Casuarina) pollen in the atmosphere of the city, and the prevalence of sensitivity in a nonatopic population. The aerobiologic survey, using a Burkard spore trap, was conducted from January 1991 to December 1994, and sensitization was ascertained by the skin prick test. The pollen season is relatively short and the pollen dispersion period occurs during October and November, mainly during the last 3 weeks of October. Diurnal patterns showed that the highest concentrations of pollen occur between 12 a.m. and 2 p.m., the most influential variables in its dispersion being temperature, sunshine, and rainfall. The prevalence of sensitization to Casuarina pollen was determined by skin prick test (SPT) in a nonatopic population of 210 patients with a previous history of autumn rhinitis, asthma, or rhinitis asthma. Six subjects showed a positive reaction to the pollen extracts, and the presence of specific IgE was demonstrated by the conventional radioallergosorbent test (RAST > or = 2) in five of these patients with positive SPT.