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Results for “Bone Demineralization, Pathologic”

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Temporomandibular joint dysfunction in children.

Sixteen pediatric patients with temporomandibular joint (TMJ) dysfunction were successfully diagnosed following appropriately selected imaging methods. The role of radiography in diagnosis of TMJ dysfunction is essential in distinguishing between the osteogenic and non-osteogenic etiologies. Computed tomography (CT) was found to be a valuable imaging method, with advantages over plain film radiography. The treatment modalities considered were: non-invasive therapy, occlusal therapy and surgical treatment. The treatment of choice was dependent on the osteogenic or non-osteogenic etiology. Surgery was considered only when the non-invasive or occlusal therapies were ineffective.

Adolescent↗

Spontaneous external auditory canal cholesteatoma complicated by rheumatoid arthritis--case report and review of the literature.

A 63-year-old woman with rheumatoid arthritis sought medical assistance for dull and chronic pain in her left ear two and half years after her initial diagnostic examination. Otoscopic examination revealed that the posteroinferior wall of the bony external ear canal was eroded and that the small cavity was filled with squamous debris. The condition was diagnosed as external auditory canal cholesteatoma (EACC). The existence of EACC might suggest complications of bone disease, aging cerumen gland, or a low migratory rate of the epithelium.

Anti-Inflammatory Agents↗

Late-onset spondyloarthropathy mimicking reflex sympathetic dystrophy syndrome.

Atypical presentations are common when spondyloarthropathy develops in older patients. We report two cases initially mistaken for reflex sympathetic dystrophy syndrome (RSDS). Both the patients were men, aged 62 and 75 years, respectively, with marked painful edema of a foot. One patient reported a moderate-energy trauma as the triggering event. Severe diffuse demineralization was noted on radiographs and diffuse hyperactivity on bone scans starting at the early vascular phase. These findings suggestive of RSDS led to treatment with calcitonin, griseofulvin, and pamidronate, all of which were ineffective. Laboratory tests showed severe inflammation, promoting investigations for other conditions. Spondyloarthropathy was diagnosed based on oligoarthritis with sacroiliitis, presence of HLA B27, and a favorable response to non-steroidal antiinflammatory therapy. In older patients, edema of the foot with severe demineralization and the laboratory evidence of inflammation should suggest a spondyloarthropathy.

Aged↗

Osteoprotegerin blocks bone cancer-induced skeletal destruction, skeletal pain and pain-related neurochemical reorganization of the spinal cord.

Bone cancer pain is common among cancer patients and can have a devastating effect on their quality of life. A chief problem in designing new therapies for bone cancer pain is that it is unclear what mechanisms drive this distinct pain condition. Here we show that osteoprotegerin, a secreted 'decoy' receptor that inhibits osteoclast activity, also blocks behaviors indicative of pain in mice with bone cancer. A substantial part of the actions of osteoprotegerin seems to result from inhibition of tumor-induced bone destruction that in turn inhibits the neurochemical changes in the spinal cord that are thought to be involved in the generation and maintenance of cancer pain. These results demonstrate that excessive tumor-induced bone destruction is involved in the generation of bone cancer pain and that osteoprotegerin may provide an effective treatment for this common human condition.

Animals↗

Oestrogen and essential fatty acid supplementation corrects bone loss due to ovariectomy in the female Sprague Dawley rat.

Essential fatty acid deficient animals develop osteoporosis. Eicosapentaenoic acid and gamma-linoleic acid have been reported to have positive effects on bone metabolism in both the growing male rat and the ovariectomized (OVX) female rat. These effects have been further investigated using a novel gamma-linolenic/eicosapentaenoic acid diester together with an oestrogen implant in the ovariectomized, female Sprague Dawley rat. Rats were sham-operated or ovariectomized at age 11 weeks. Two groups of OVX rats received an oestrogen implant at ovariectomy. Animals received fatty acids, linoleic acid (control) or a diester with gamma-linolenic acid and eicosapentaenoic acid as part of a semi-synthetic diet. Bone calcium content and excretion of deoxypyridinolines as marker of bone degradation were measured at 14 weeks. Oestrogen, as well as diester alone, increased calcium/femur to sham levels. Oestrogen plus diester potentiated the effect of oestrogen on bone calcium (P < 0.05 vs OVX). At the same time, oestrogen alone and the combination of oestrogen plus diester significantly reduced (P < 0.05 vs OVX) urinary deoxypyridinoline and hydroxyproline excretion. Again, the diester potentiated the effect of oestrogen. The effects of the diester alone, together with the potentiated effects of oestrogen by the essential fatty acids on osteoporosis, are novel findings.

Amino Acids↗

Disuse osteoporosis as evidence of brachial plexus palsy due to intrauterine fetal maladaptation.

We report what may be overlooked evidence of the effects of intrauterine maladaptation as a cause of brachial plexus palsy. A case of total brachial plexus palsy in the posterior arm associated with Horner's syndrome and severe demineralization of the bones of the affected arm is analyzed. In this litigated case, a report of marked demineralization of the bones of the affected arm was analyzed by the plaintiff's radiology expert as diagnostic of disuse osteoporosis. The presence of clear-cut evidence of disuse osteoporosis during the early neonatal period is compelling evidence of an intrauterine onset of brachial plexus palsy.

Adult↗

Inferred functions of "novel" genes identified in fibroblasts chondroinduced by demineralized bone.

Little is known about the cellular mechanisms that control postnatal chondrocyte differentiation. As a first step towards identifying those mechanisms, gene expression shifts were characterized in an in vitro model of chondroinduction. In previous studies, several functional classes of genes (cytoskeletal and matrix elements, cell adhesion proteins, peptide growth factors, and signal transduction proteins) were found to be altered in human dermal fibroblasts (hDFs) cultured in porous collagen sponges with chondroinductive demineralized bone powder (DBP) for 3 days. In addition, a number of "novel" sequences were identified. In this study, molecular techniques were combined with computational methods to characterize those sequences. Gene expression of all 10 novel sequences tested was found in hDFs by RT-PCR. The sequences were compared to the human genome, and their cellular functions were inferred from genes that mapped to the same chromosomal coordinates. Only one of the novel sequences contained a protein-coding region (kinesin superfamily protein 26B). The others contained 3' untranslated (osteonectin, alpha-V integrin, RAP2B) or other untranslated regions (PTPN21, GAS6) of mRNAs. The cellular functions of the DBP-regulated genes described in this study fall into similar categories as those previously identified. These results provide new details on the cellular response of hDFs exposed to DBP.

3' Untranslated Regions↗

Association between phosphate removal and markers of bone turnover in haemodialysis patients.

BACKGROUND: As the main mineral reservoir, bone acts as a calcium (Ca) and phosphate buffering system. Accordingly, phosphate removal by haemodialysis (HD) might be theoretically influenced by bone turnover, as well as by the interaction of regulatory molecules, such as PTH and osteoprotegerin (OPG). The present study investigated the relationship between these variables and phosphate removal by HD. METHODS: Blood samples for serum Ca, phosphate, bicarbonate, intact PTH, PTH (1-84), bone alkaline phosphatase, tartrate-resistant acid phosphatase 5b, OPG and receptor activator of nuclear factor-kappaB ligand (RANKL) were obtained in 28 HD patients. Phosphate removal was measured by a continuous collection of the dialysate. RESULTS: Pre-dialysis serum phosphate concentration is the critical factor in determining dialytic phosphate removal. However, multiple regression analysis reveals that phosphate removal is better explained by a combination of factors than by phosphate concentration alone. In this model, the PTH/OPG ratio is an additional positive factor, whereas age and vitamin D treatment are negative factors. Patients with pre-HD bicarbonate higher than 20 mEq/l had higher serum phosphate and, accordingly, higher phosphate removal; of interest, these individuals also have significant differences in RANKL/OPG. Mean (SD) OPG levels were significantly higher than that in the healthy population (16.2 (12.5) pmol/l; these values correlated with age (r = 0.4, P<0.04). Mean serum RANKL (1.03 (1.02) pmol/l) was within the range of normal individuals. CONCLUSIONS: Dialytic phosphate removal has a crucial, direct relationship with pre-HD plasma phosphate levels. However, the phenomenon of phosphate removal is more precisely explained using a more complex relationship, defined by the interaction between serum phosphate, PTH/OPG, age and vitamin D administration. Serum RANKL levels are first reported in HD patients, and are not different from the normal population.

Adult↗

Nutrition in space.

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Adaptation, Physiological↗

Sodium-phosphate cotransporters, nephrolithiasis and bone demineralization.

PURPOSE OF REVIEW: We discuss how recent findings obtained in disorders of phosphate metabolism in humans and in animal models have provided insights into the pathogenesis of renal stone formation and bone demineralization. RECENT FINDINGS: Mice that are null for the sodium-phosphate cotransporter (NPT)2a gene (NPT2a(-/-) mice) exhibit hypophosphataemia, increased urinary phosphate excretion, hypercalciuria and nephrolithiasis, but no bone demineralization. Mice null for the sodium-hydrogen exchanger regulatory factor (NHERF)1 (NHERF1(-/-) mice) also exhibit hypophosphataemia and increased renal phosphate excretion with decreased renal NPT2a expression, but they present with a severe sex-dependent bone demineralization. Heterozygous loss-of-function mutations in the NPT2a gene in humans induce hypophosphataemia, increased urinary phosphate excretion, hypercalciuria, nephrolithiasis in males (to date) and bone demineralization of variable severity in both sexes. Patients and experimental animals with increased circulating levels of fibroblast growth factor 23 present with hypophosphataemia, increased urinary phosphate excretion, inappropriate calcitriol synthesis and rickets/osteomalacia, but no nephrolithiasis except when treated. Low-phosphate diet in spontaneously hypercalciuric rats and disruption of the 1-alpha-hydroxylase gene in NPT2a mice prevent renal stone formation. SUMMARY: Increased urinary phosphate excretion is a risk factor for renal calcium stone formation when it is associated with hypercalciuria. As yet undefined interplay between NPT2a, NHERF1 and possibly other cotransporters or associated proteins in bone cells may account for the diversity of bone phenotypes observed in disorders of phosphate metabolism with impaired renal phosphate reabsorption. The pathogenesis of both renal stone and bone demineralization appear to be affected by species, sex and mutation type, among other factors.

Animals↗

Computerized quantification of joint space narrowing and periarticular demineralization in patients with rheumatoid arthritis based on digital x-ray radiogrammetry.

OBJECTIVES: The aim of our work was to evaluate digital x-ray radiogrammetry (DXR) for the quantification of disease-related periarticular demineralization and computerized analysis of joint space distances (JSDA) for the measurement of joint space narrowing as a new diagnostic method for the early detection of joint-associated alterations and for monitoring disease progression in patients with rheumatoid arthritis (RA). MATERIALS AND METHODS: Digital radiographs in 313 patients with varying severity of RA were performed annually and assessed by 2 radiologists using modified Larsen and also the Sharp scores within an observation period of 3 years. The hand radiographs underwent measurements of bone mineral density (BMD) and metacarpal index (MCI) by DXR, as well as computerized JSDA at the metacarpal-phalangeal articulation (JSD-MCP) for a cross-sectional and longitudinal study design. RESULTS: Both DXR-BMD (-29.6%; P < 0.01) and DXR-MCI (-31.0%; P < 0.01) revealed a notable reduction dependent on the severity of RA (from grade 1 to grade 5 of the modified Larsen score); the severity dependent decrease of mean JSD-MCP ranged from -31.9% (P < 0.01; Sharp erosion part) to -39.1% (P < 0.01) for the modified Larsen score. Over an observation period of 3 years, a significant decrease of DXR-BMD (-22.3%) and DXR-MCI (-23.3%) as well as JSD-MCP mean (-17.5%) was observed (P < 0.05), whereas an accentuated decline of DXR and JSDA parameters was verified for patients without disease-modifying antirheumatic drugs or methotrexate therapy. CONCLUSION: Computerized analysis of hand radiographs by DXR and JSDA is a promising approach to assess the severity and to monitor the progression of RA because DXR and JSDA are timely able to measure periarticular demineralization and also narrowing of JSD-MCP dependent on the severity, the medical treatment and the course of RA.

Absorptiometry, Photon↗

Space flight rehabilitation.

The weightless environment of space imposes specific physiologic adaptations on healthy astronauts. On return to Earth, these adaptations manifest as physical impairments that necessitate a period of rehabilitation. Physiologic changes result from unloading in microgravity and highly correlate with those seen in relatively immobile terrestrial patient populations such as spinal cord, geriatric, or deconditioned bed-rest patients. Major postflight impairments requiring rehabilitation intervention include orthostatic intolerance, bone demineralization, muscular atrophy, and neurovestibular symptoms. Space agencies are preparing for extended-duration missions, including colonization of the moon and interplanetary exploration of Mars. These longer-duration flights will result in more severe and more prolonged disability, potentially beyond the point of safe return to Earth. This paper will review and discuss existing space rehabilitation plans for major postflight impairments. Evidence-based rehabilitation interventions are imperative not only to facilitate return to Earth but also to extend the safe duration of exposure to a physiologically hostile microgravity environment.

Adaptation, Physiological↗

New patients: should children be treated differently?

Inflammatory bowel disease (IBD) in childhood is often diagnosed at a vulnerable time of growth and development, and is recognized as one of the most significant chronic gastrointestinal diseases to affect children. Children and adolescents with IBD are at increased risk of complications as a result of malnutrition secondary to reduced appetite, increased metabolism and decreased absorptive capacity. The most common and serious complications are growth failure, bone demineralization and impaired psychosocial development. These issues add to the complexity of childhood IBD management and it is essential that adequate medical management is in place to prevent these long-term complications. Current treatment options include 5-aminosalicylic acid, antibiotics, corticosteroids, nutritional therapy and immunomodulators used to induce and maintain remission; some are specifically employed to maintain a steroid free long-term remission. As a general rule, long-term corticosteroid use should be avoided to reduce the risk of bone demineralization and growth failure. Newer treatment options such as infliximab have been shown to be effective for inducing and prolonging remission of Crohn's disease in children and paediatric use of infliximab is likely to increase in the near future. A recent case report, involving a 15-year old boy presenting with abdominal pain and bloody diarrhoea, illustrates the difficulty in correctly diagnosing IBD in children and the need for optimizing therapy to achieve treatment success.

Adolescent↗

The next small step.

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Adaptation, Physiological↗

Summary of final report: Space Life Sciences Planning Workshop (SLSPW). June 5-7, 2000 Mont Tremblant, Quebec.

A Space Life Sciences Planning Workshop was sponsored by the Canadian Space Agency to identify key questions in the major research areas supported by the Life Sciences Program, to identify Canadian strengths and capabilities as they relate to these research areas, and to make recommendations for the future directions of the Life Sciences Program. The conclusions reached by the workshop participants have been presented to the Canadian Space Agency. This report is a summary of those conclusions.

Biological Science Disciplines↗

Comments on the clinical application of fibronectin in dentistry.

Several studies have demonstrated that citric acid demineralization of the root surface promotes tissue attachment. Since demineralization exposes collagen to which fibronectin binds, the role of fibronectin in the attachment of cells to the tooth surface has been of considerable interest. It is clear that fibronectin and other cell adhesion proteins can promote cell attachment to the tooth surface; therefore, attempts have been made to utilize these findings in a clinical setting. Using a quantitative ELISA procedure to measure the binding of fibronectin to demineralized bone and tooth, we have found that 1 microgram fibronectin can saturate approximately 1 mg of either demineralized bone or demineralized tooth powder. Since serum contains 300 micrograms fibronectin per mL, the bleeding that occurs during oral surgery should saturate exposed tooth surfaces with amounts of fibronectin adequate for cell adhesion. Thus, exogenous fibronectin would appear to be of little clinical benefit.

Animals↗