Effects of Vitamin D Supplementation during the Induction and Progression of Osteoarthritis in a Rat Model.

Epidemiological studies correlate low levels of vitamin D with the osteoarthritis (OA) progression. Cytokines and metalloproteases play a major role in OA promoting the inflammation and degradation of the cartilage and can be induced through the Toll-like receptor (TLR) pathway. The aim of this study was to evaluate the protective effect of vitamin D supplementation on the development of osteoarthritis (OA) through examining the genetic regulation of TLRs, cytokines, and metalloproteases in chondrocytes as well as the wideness of cartilage in rats with OA. Our results demonstrate that the signaling through TLR-4 is a proinflammatory mechanism in osteoarthritis that drives the upregulation of MMP-3, IL-1ß, and TNF-α gene expression, leading to cartilage degradation and inflammation. Vitamin D supplementation had a protective effect during the onset but not during the chronic stage of OA in the rat model.

Cell death of chondrocytes is a combination between apoptosis and autophagy during the pathogenesis of Osteoarthritis within an experimental model.

The death of chondrocytes and the loss of extracellular matrix are the central features in cartilage degeneration during Osteoarthritis (OA) pathogenesis. The mechanism by which chondrocytes are removed in OA cartilage are still not totally defined, although previous reports support the presence of apoptotic as well as non apoptotic signals. In addition, in 2004 Roach and co-workers suggested the term "Chondroptosis" to design the type of cell death present in articular cartilage, which include the presence of some apoptotic and autophagic processes. To identify the mechanisms, as well as the chronology by which chondrocytes are eliminated during OA pathogenesis, we decided to evaluate apoptosis (by active caspase 3 and TUNEL signal) and autophagy (by LC3II molecule and cytoplasmic vacuolization) using Immunohistochemistry and Western blot techniques in an animal OA model. During OA pathogenesis, chondrocytes exhibit modifications in their death process in each zone of the cartilage. At early stages of OA, the death of chondrocytes starts with apoptosis in the superficial and part of the middle zones of the cartilage, probably as a consequence of a constant mechanical damage in the joint. As the degenerative process progresses, high incidence of active caspase 3 as well as LC3II expression are observed in the same cell, which indicate a combination of both death processes. In contrast, in the deep zone, due the abnormal subchondral bone ossification during the OA pathogenesis, apoptosis is the only mechanism observed.

Prolactin inhibits the apoptosis of chondrocytes induced by serum starvation.

The apoptosis of chondrocytes plays an important role in endochondral bone formation and in cartilage degradation during aging and disease. Prolactin (PRL) is produced in chondrocytes and is known to promote the survival of various cell types. Here we show that articular chondrocytes from rat postpubescent and adult cartilage express the long form of the PRL receptor as revealed by immunohistochemistry of cartilage sections and by RT-PCR and Western blot analyses of the isolated chondrocytes. Furthermore, we demonstrate that PRL inhibits the apoptosis of these same chondrocytes cultured in low-serum. Chondrocyte apoptosis was measured by hypodiploid DNA content determined by flow cytometry and by DNA fragmentation evaluated by the ELISA and the TUNEL methods. The anti-apoptotic effect of PRL was dose-dependent and was prevented by heat inactivation. These data demonstrate that PRL can act as a survival factor for chondrocytes and that it has potential preventive and therapeutic value in arthropathies characterized by cartilage degradation.

Cytoskeleton disruption in chondrocytes from a rat osteoarthrosic (OA) -induced model: its potential role in OA pathogenesis.

Morphological and functional changes of chondrocytes are typical in OA cartilage. In this work, we have described noteworthy changes in intermediate filaments cytoskeleton evidenced by transmission electron microscopy. Alterations in the distribution as well as in the content of vimentin, actin, and tubulin have been described by specific fluorescence labelling of each cytoskeletal component and confocal analysis. Normal vs OA cartilages showed a reduction in the percentage of labelled chondrocytes of 37.1% for vimentin, 4.7% for actin, and 20.1% for tubulin. Statistical analysis of fluorescence intensities (mean % +/- SEM) between normal and OA rat cartilage revealed a highly significant difference in vimentin, a significant difference in tubulin, and a non-significant difference in actin. Moreover, by western blot, altered electrophoretic patterns were observed mainly for vimentin and tubulin in OA cartilage in comparison with normal cartilage. These results allow us to suggest that substantial changes in vimentin and tubulin cytoskeleton of chondrocytes might be involved in OA pathogenesis.

Use of microscopical techniques in the study of human chondrocytes from osteoarthritic cartilage: an overview.

Several microscopical techniques, such as high resolution light microscopy, Normaski microscopy, laser confocal and transmission electron microscopy, were used in a correlative morphological study of human osteoarthritic (OA) cartilage. Emphasis was made on the characterization of chondrocytes heterogeneity observed in this tissue. Novel findings were assessed in the morphological and immunocytological study of the chondrocytes organized in aggregates or "clones" typical of this degenerative disease, consisting of the modification of certain elements of the cytoskeleton that influence changes in the cell shape. Also, the presence of cilia and centrioles found in certain cell raised the question if chondrocytes are able to move and regroup as an alternative mechanism to mitosis in the formation of cell clusters or "clones." The presence of two types of secretory chondrocytes was observed and discussed. The use of a correlative approach of several microscopical techniques in a systematic morphological and immunocytological characterization of chondrocyte population within the fibrillated and nonfibrillated human osteoarthritic cartilage gave complementary information that could be important for a better understanding of the histopathogenesis of OA.

Resection of suprasellar tumors by using a modified transsphenoidal approach. Report of four cases.

Generally accepted contraindications to using a transsphenoidal approach for resection of tumors that arise in or extend into the suprasellar region include a normal-sized sella turcica, normal pituitary function, and adherence of tumor to vital intracranial structures. Thus, the transsphenoidal approach has traditionally been restricted to the removal of tumors involving the pituitary fossa and, occasionally, to suprasellar extensions of such tumors if the sella is enlarged. However, conventional transcranial approaches to the suprasellar region require significant brain retraction and offer limited visualization of contralateral tumor extension and the interface between the tumor and adjacent structures, such as the hypothalamus, third ventricle, optic apparatus, and major arteries. In this paper the authors describe successful removal of suprasellar tumors by using a modified transsphenoidal approach that circumvents some of the traditional contraindications to transsphenoidal surgery, while avoiding some of the disadvantages of transcranial surgery. Four patients harbored tumors (two craniopharyngiomas and two hemangioblastomas) that arose in the suprasellar region and were located either entirely (three patients) or primarily (one patient) within the suprasellar space. All patients had a normal-sized sella turcica. Preoperatively, three of the four patients had significant endocrinological deficits signifying involvement of the hypothalamus, pituitary stalk, or pituitary gland. Two patients exhibited preoperative visual field defects. For tumor excision, a recently described modification of the traditional transsphenoidal approach was used. Using this modification, one removes the posterior portion of the planum sphenoidale, allowing access to the suprasellar region. Total resection of tumor was achieved (including absence of residual tumor on follow-up imaging) in three of the four patients. In the remaining patient, total removal was not possible because of adherence of tumor to the hypothalamus and midbrain. One postoperative cerebrospinal fluid leak occurred. Postoperative endocrinological function was worse than preoperative function in one patient. No other new postoperative endocrinological or neurological deficits were encountered. This study demonstrates the feasibility of using a modified transsphenoidal approach for resection of certain suprasellar, nonpituitary tumors.

Relationship of subjective disability with pain intensity, pain duration, pain location, and work-related factors in nonoperated patients with chronic low back pain.

OBJECTIVE: A cross-sectional study on patients with chronic low back pain to compare relationships between subjective disability and pain intensity, pain duration, pain location, and work-related factors. DESIGN AND SUBJECTS: One hundred and seven outpatients with low back pain, with or without radiation to the legs, of at least 3 months' duration, were administered a comprehensive back patient questionnaire. The questionnaire included the Pain Disability Index (PDI) for the assessment of overall perceived disability and assessments of pain intensity, duration, and location and two pretested short-form work questionnaires. None of the patients had undergone a back operation. SETTING: Tertiary care center. RESULTS: There was evidence of significant interrelationships between the PDI and pain intensity (low back pain, r = 0.53, p < 0.001; leg pain, r = 0.32, p < 0.01; and buttock pain, r = 0.36, p < 0.01), pain location (significantly higher scores with distal pain radiation), and work-related factors (a work load sum score of r = 0.31, p < 0.01; significantly higher scores in patients on sick leave). CONCLUSIONS: The results suggest that subjective disability in patients with chronic low back pain overlaps with both pain and work-related factors. The observations support the multidimensionality of low back disability.

Intercorrelation and test-retest reliability of the Pain Disability Index (PDI) and the Oswestry Disability Questionnaire (ODQ) and their correlation with pain intensity in low back pain patients.

OBJECTIVE: To determine the intercorrelation between subjective disability, as assessed with the Pain Disability Index (PDI) and the Oswestry Disability Questionnaire (ODQ) and their correlation with visual analogue scale (VAS) pain intensity ratings. DESIGN AND SUBJECTS: Questionnaires were administered to 94 patients with chronic low back pain with or without radiation into the legs of at least 3 months' duration. SETTING: Tertiary care center. RESULTS: High correlations were noted between the ODQ and PDI (r = 0.83) and PDI factor 1 (r = 0.84), a subscale of the PDI. Lower correlations were noted between pain intensity (VAS) scores and the ODQ (r = 0.62) and the PDI (r = 0.69). A weaker correlation (r = 0.41) was noted between the ODQ and PDI factor 2. Intraclass correlation coefficients (ICC) for test-retest reliability in 20 patients (time interval 1 week) were for the ODQ ICC = 0.83, PDI ICC = 0.91, PDI percentage score ICC = 0.91, PDI factor 1 ICC = 0.87, and PDI factor 2 ICC = 0.73, respectively. CONCLUSIONS: The present results suggest that either the PDI or the percentage score PDI and also the even shorter-to-administer PDI factor 1 may be useful and reliable tests for the assessment of subjective disability in low back pain patients. As noted by the moderate intercorrelations with pain intensity scores, both the PDI and the ODQ address a broader concept of disability than that directly related to pain intensity.

Intermittent mitral regurgitation and pulmonary edema after aortic valve replacement.

We report intermittent mitral valve regurgitation with 17 acute pulmonary edemas over a 16-month period after aortic valve replacement due to combined aortic valve disease in a 51-year-old man. The mechanism of mitral regurgitation was explained by the relatively large size of the prosthetic valve which had had to be sutured partly below the aortic annulus. It was suspected to interfere with the closure of the mildly diseased mitral valve when under pressure or subjected to volume loadings of the left ventricle which provoked free mitral regurgitation. There was no recurrence of pulmonary edema in the 50 months following mitral valve replacement.

Variability in the cell phenotype of aggregates or "clones" of human osteoarthritic cartilage. A case report.

Human samples of articular cartilage from the knee of a clinically classified osteoarthritic patient, assessed by arthroscopy as part of the surgical treatment was studied by light and transmission electron microscopy. This particular case differed from others already reported in the variability of cell phenotype within the aggregates or "clones" frequently present in the osteoarthritic cartilage. The most common morphology of "clonal" cells forming the aggregates were large and rounded with an euchromatic nucleus. The cytoplasm was characterized by the presence of alternately clear and dense sites. At the ultrastructural level it was seen that the clear sites were formed by disrupted intermediates filaments and small particles, and that the dense sites were constituted by the segregation of different organelles of the chondrocytes. In addition, there were atypical aggregates composed only by secretory cells or by degenerating chondrocytes. Furthermore, a complex structure consisting of a very large cell inside a giant lacunae delimited by electron-dense material with small vesicles is described as a novel finding. The variability in the chondrocyte phenotype of the aggregates described here could be an indication of a better prognosis; nevertheless, the follow-up of the evolution of this patient is needed in order to know the final outcome.

Shark fisheries in the Southeast Pacific: A 61-year analysis from Peru.

Peruvian waters exhibit high conservation value for sharks. This contrasts with a lag in initiatives for their management and a lack of studies about their biology, ecology and fishery. We investigated the dynamics of Peruvian shark fishery and its legal framework identifying information gaps for recommending actions to improve management. Further, we investigated the importance of the Peruvian shark fishery from a regional perspective. From 1950 to 2010, 372,015 tons of sharks were landed in Peru. From 1950 to 1969, we detected a significant increase in landings; but from 2000 to 2011 there was a significant decrease in landings, estimated at 3.5% per year. Six species represented 94% of landings: blue shark ( Prionace glauca), shortfin mako ( Isurus oxyrinchus), smooth hammerhead ( Sphyrna zygaena), common thresher ( Alopias vulpinus), smooth-hound ( Mustelus whitneyi) and angel shark ( Squatina californica). Of these, the angel shark exhibits a strong and significant decrease in landings: 18.9% per year from 2000 to 2010. Peru reports the highest accumulated historical landings in the Pacific Ocean; but its contribution to annual landings has decreased since 1968. Still, Peru is among the top 12 countries exporting shark fins to the Hong Kong market. Although the government collects total weight by species, the number of specimens landed as well as population parameters (e.g. sex, size and weight) are not reported. Further, for some genera, species-level identification is deficient and so overestimates the biomass landed by species and underestimates the species diversity. Recently, regional efforts to regulate shark fishery have been implemented to support the conservation of sharks but in Peru work remains to be done.

Impact of coronary artery bypass surgery on ischemic mitral regurgitation.

INTRODUCTION: To determine the course of ischemic mitral regurgitation (IMR) after coronary artery bypass grafting (CABG), and evaluate preoperative factors which predict the development of the severity of IMR after CABG. METHODS: Between 1992-2005, 1995 patients underwent CABG and 170 of them had IMR. Data of 131 patients were retrospectively analyzed and living patients (n = 112) had a clinical follow-up visit. The mean follow-up time was 6.5 years. RESULTS: At the time of CABG, 66% of the 131 cases analyzed had mild, 31% had moderate, and 3% had severe IMR. At the time of follow-up, 52% of patients had either no IMR or mild IMR, 27% had moderate IMR, 6% had severe IMR and 15% suffered from cardiac related death. During follow-up IMR grade reduced in 25% of study patients. None of the patient had re-operation due to the mitral regurgitation. Multivariate analysis showed that left ventricular ejection fraction (LVEF) was an independent predictor of good prognosis (O.R. 1.4, 95% C.I. 1.15-1.83/ 10% increase of LVEF, p = 0.02). CONCLUSION: Half of the patients, who have IMR at the time of CABG, have no IMR or only mild IMR postoperatively. Good LVEF adds to the probability that CABG only can reduce IMR.

Do chondrocytes undergo "activation" and "transdifferentiation" during the pathogenesis of osteoarthritis? A review of the ultrastructural and immunohistochemical evidence.

Chondrocytes, which are the only cell type in the articular cartilage, show substantial morphological and functional differences, depending on their location within the tissue. In OA cartilage, outstanding modifications have been reported concerning their structure and functions. Based on the principle that both structure and function run in a parallel manner, new concepts are arising related to morphological observations. Observations on OA chondrocytes, such as cytoskeleton disruption, development of the secretory machinery (rough endoplasmic reticulum and Golgi complex), and cell death by apoptosis, among others, certainly must be related to the role of chondrocytes in OA pathogenesis. In this degradative process, it has been acknowledged that cell death, matrix degradation and subchondral bone remodelling are the main causes of cartilage breakdown in osteoarthritis. The aim of this review was to correlate and integrate in a logical manner the modifications of chondrocytes with cartilage breakdown during osteoarthritis pathogenesis. Furthermore, we intend to open a debate on cell cycle and mitosis, as well as on signalling molecules that might be involved in the morphofunctional changes in OA chondrocytes, which we propose to name "activation" and "transdifferentiation" of chondrocytes. We expect this analysis to be useful for studying OA pathogenesis in depth, with the aim of finding new strategies for the early diagnosis and therapeutic procedures for this invalidating disease, which is already an important public health problem.

Chondroptosis: an immunohistochemical study of apoptosis and Golgi complex in chondrocytes from human osteoarthritic cartilage.

The Golgi complex is thought to play an important role in the apoptotic process of osteoarthritic (OA) chondrocytes. However, the exact relationship between modifications of the Golgi complex and apoptosis in human OA cartilage requires to be established. We compared the patterns and immunolabeling intensities for anti-Golgi 58 K protein with apoptosis markers such as TUNEL and caspase-2L in OA cartilage removed from patients during knee total replacement surgery. We observed important modifications in labeling of the Golgi 58 K protein in OA chondrocytes compared with normal cell. Immunohistochemical analysis revealed co-localization between 58 K protein and caspase-2L, suggesting that this enzyme was localized in Golgi complex of OA chondrocytes. In addition, these cells labeled positive with the TUNEL technique, but in different proportions to caspase-2L. Our results support the concept, previously reported, that apoptosis in OA cartilage (chondroptosis) might be a variant of the classical apoptosis.

Relationships between spinal mobility, physical performance tests, pain intensity and disability assessments in chronic low back pain patients.

Correlations between the Oswestry Disability Questionnaire (ODQ), the Pain Disability Index (PDI), PDI subscales PDI factor 1 (PDI 1), PDI factor 2 (PDI 2) and visual analogue scale (VAS) pain intensity on the one hand and spine range of motion measures and static and dynamic functional performance tests on the other, were studied in 52 chronic low back pain patients. Comparable groups of male and female patients were studied. A moderately significant (p < 0.01) inverse correlation was observed between the ODQ and rotation to the left even after correction for age, but not when men and women were studied separately. A significant (r = -0.480, p < 0.001) inverse correlation was observed between the repeated squatting test and pain intensity and in men both pain intensity and disability correlated (r = -0.607, p < 0.001) with this particular test. Only for the women were there moderately significant (p < 0.01) inverse correlations between disability assessments and all the physical performance tests with the exception of the static back muscle test. In the women only the isometric lifting test showed a moderately significant inverse correlation (r = -0.504, p < 0.01) with pain intensity. Such apparent gender differences in the overlap between physical performance tests and self-report disability assessments and pain intensity may be clinically relevant. The results will, however, require confirmation on larger groups of chronic low back pain patients.

Hyperpolarisation of rat peritoneal macrophages phagocytosing latex particles.

The changes that take place in the plasma membrane during endocytosis are still poorly understood. Studies of the electrical properties and related permeabilities of cells during pinocytosis and phagocytosis should provide insight into these changes. This approach has not been much exploited, although there have been a few relevant reports. For example, induction of pinocytosis in amoebae produces a marked decrease in plasma membrane resistance, and exposure of polymorphonuclear leukocytes to phagocytosable particles can engender alterations in ionic permeabilities. The present report demonstrates that the induction of phagocytosis in rat peritoneal macrophages is accompanied by a sustained hyperpolarisation of the cells.

Chondroptosis: a variant of apoptotic cell death in chondrocytes?

Evidence has accumulated in recent years that programmed cell death (PCD) is not necessarily synonymous with the classical apoptosis, as defined by Kerr and Wyllie, but that cells use a variety of pathways to undergo cell death, which are reflected by different morphologies. Although chondrocytes with the hallmark features of classical apoptosis have been demonstrated in culture, such cells are extremely rare in vivo. The present review focuses on the morphological differences between dying chondrocytes and classical apoptotic cells. We propose the term 'chondroptosis' to reflect the fact that such cells are undergoing apoptosis in a non-classical manner that appears to be typical of programmed chondrocyte death in vivo. Unlike classical apoptosis, chondroptosis involves an initial increase in the endoplasmic reticulum and Golgi apparatus, reflecting an increase in protein synthesis. The increased ER membranes also segment the cytoplasm and provide compartments within which cytoplasm and organelles are digested. In addition, destruction occurs within autophagic vacuoles and cell remnants are blebbed into the lacunae. Together these processes lead to complete self-destruction of the chondrocyte as evidenced by the presence of empty lacunae. It is speculated that the endoplasmic reticulum pathway of apoptosis plays a greater role in chondroptosis than receptor-mediated or mitochondrial pathways and that lysosomal proteases are at least as important as caspases. Because chondroptosis does not depend on phagocytosis, it may be more advantageous in vivo, where chondrocytes are isolated within their lacunae. At present the initiation factors or the molecular pathways involved in chondroptosis remain unclear.

Cutaneous withdrawal reflexes of the upper extremity.

We characterized reflexes of the upper limb elicited by electrical stimulation of the fingers. Surface electromyogram (EMG) was recorded from several upper extremity muscles, and a finger was stimulated through paired ring electrodes. A train of 4-10 shocks at a frequency of 300 Hz and an intensity 4-6 times the perceptual threshold was the most effective stimulus for evoking EMG activity in relaxed arm muscles. Habituation was prominent. Latencies of EMG activity were <100 ms for most proximal and forearm muscles, and at least 40 ms prior to voluntary withdrawal movements. The timing of EMG activity in arm muscles was similar to that of the E2 component of the cutaneomuscular reflex evoked in these same muscles during contraction, and coincided with a silent period in active hand muscles. We conclude that cutaneous stimuli to the fingers activate a complex motor pattern that tends to withdraw the hand at the same time the grasp is released.