Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P50502 (Hip)
 7,003 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

For many years, acrylic cement has been regarded as the unique available means for a long term and secure fixation of components in hip arthroplasty. A new generation of uncemented implants coated in hydroxyapatite (HA) has arisen since the mid-1980s, aiming to provide a 'biological interface' between metal and surrounding bone, and thus the hydroxyapatite interface was defined some years ago as a distinct entity from both cemented and 'plain porous' fixation. Based upon our 20-year experience with the HA Omnifit stem, this paper aims to discuss the efficiency of hydroxyapatite as a means of fixation for femoral components in hip arthroplasty, then examine whether the addition of a calcium phosphate layer induces any adverse effects, and finally make comparisons between HA-coated versus porous hip stems reported in the literature. With respect to fixation of femoral components in hip arthroplasty we report excellent results from the partially coated HA Omnifit stem in our series, with 99.20% of survival rate at 17-year follow-up, these results being consistent and similar to other HA series in the literature. HA 'uncemented' fixation can therefore be considered reliable and efficient. Furthermore, two decades of hydroxyapatite coatings have resulted in the identification of no major adverse effects. In fact calcium phosphate ions participate in the physiological turn-over of bone remodelling, and the HA coating is replaced by new bone formation without any fibrous tissue layer. Since HA particles are biodegradable and do not produce any inflammatory reaction in the surrounding bone, fears of osteolysis or third body wear due to HA debris have not been confirmed. Finally, comparison between HA versus plain porous femoral components through the literature has demonstrated better results with HA than porous alone both in terms of the quantity and quality of bone remodelling, and the potential migration and subsidence of the stem.
Hip Int
PMID:Uncemented stems in hip replacement--hydroxyapatite or plain porous: does it matter? Based on a prospective study of HA Omnifit stems at 15-years minimum follow-up. 1864 78

The etiology and pathogenesis of non-traumatic osteonecrosis of the femoral head is still unknown although many studied has been performed. Using Magnetic resonance imaging, decision of the extent and location of the necrotic lesion, exist of bone marrow oedema has been developed. The revised criteria for diagnosis, classification, and staging of the disease from specific disease investigation committee of Japanese ministry of health, labor and welfare was established. As joint preservation operation, transtrochanteric rotational osteotomy, curved varus osteotomy were proved to be effective. Hip arthroplasty for maintaining bone stock has been developed for the treatment of young patients.
Clin Calcium 2008 Aug
PMID:[Bone disease with Pain. Non-traumatic osteonecrosis of the femoral head]. 1867 58

Osteoporosis, the most prevalent metabolic bone disease among older people, increases risk for low trauma hip fractures (HF) that are associated with high morbidity and mortality. Hip bone size (BS) has been identified as one of the key measurable risk factors for HF. Although hip BS is highly genetically determined, genetic factors underlying the trait are still poorly defined. Here, we performed the first genome-wide association study (GWAS) of hip BS interrogating approximately 380,000 SNPs on the Affymetrix platform in 1,000 homogeneous unrelated Caucasian subjects, including 501 females and 499 males. We identified a gene, PLCL1 (phospholipase c-like 1), that had four SNPs associated with hip BS at, or approaching, a genome-wide significance level in our female subjects; the most significant SNP, rs7595412, achieved a p value of 3.72x10(-7). The gene's importance to hip BS was replicated using the Illumina genotyping platform in an independent UK cohort containing 1,216 Caucasian females. Two SNPs of the PLCL1 gene, rs892515 and rs9789480, surrounded by the four SNPs identified in our GWAS, achieved p values of 8.62x10(-3) and 2.44x10(-3), respectively, for association with hip BS. Imputation analyses on our GWAS and the UK samples further confirmed the replication signals; eight SNPs of the gene achieved combined imputed p values<10(-5) in the two samples. The PLCL1 gene's relevance to HF was also observed in a Chinese sample containing 403 females, including 266 with HF and 177 control subjects. A SNP of the PLCL1 gene, rs3771362 that is only approximately 0.6 kb apart from the most significant SNP detected in our GWAS (rs7595412), achieved a p value of 7.66x10(-3) (odds ratio = 0.26) for association with HF. Additional biological support for the role of PLCL1 in BS comes from previous demonstrations that the PLCL1 protein inhibits IP3 (inositol 1,4,5-trisphosphate)-mediated calcium signaling, an important pathway regulating mechanical sensing of bone cells. Our findings suggest that PLCL1 is a novel gene associated with variation in hip BS, and provide new insights into the pathogenesis of HF.
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PMID:Identification of PLCL1 gene for hip bone size variation in females in a genome-wide association study. 1877 29

Hedgehog (Hh) proteins specify tissue pattern in metazoan embryos by forming gradients that emanate from discrete sites of expression and elicit concentration-dependent cellular differentiation or proliferation responses. Cellular responses to Hh and the movement of Hh through tissues are both precisely regulated, and abnormal Hh signalling has been implicated in human birth defects and cancer. Hh signalling is mediated by its amino-terminal domain (HhN), which is dually lipidated and secreted as part of a multivalent lipoprotein particle. Reception of the HhN signal is modulated by several cell-surface proteins on responding cells, including Patched (Ptc), Smoothened (Smo), Ihog (known as CDO or CDON in mammals) and the vertebrate-specific proteins Hip (also known as Hhip) and Gas1 (ref. 11). Drosophila Ihog and its vertebrate homologues CDO and BOC contain multiple immunoglobulin and fibronectin type III (FNIII) repeats, and the first FNIII repeat of Ihog binds Drosophila HhN in a heparin-dependent manner. Surprisingly, pull-down experiments suggest that a mammalian Sonic hedgehog N-terminal domain (ShhN) binds a non-orthologous FNIII repeat of CDO. Here we report biochemical, biophysical and X-ray structural studies of a complex between ShhN and the third FNIII repeat of CDO. We show that the ShhN-CDO interaction is completely unlike the HhN-Ihog interaction and requires calcium, which binds at a previously undetected site on ShhN. This site is conserved in nearly all Hh proteins and is a hotspot for mediating interactions between ShhN and CDO, Ptc, Hip and Gas1. Mutations in vertebrate Hh proteins causing holoprosencephaly and brachydactyly type A1 map to this calcium-binding site and disrupt interactions with these partners.
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PMID:The mode of Hedgehog binding to Ihog homologues is not conserved across different phyla. 1879 98

Lactation is known to be associated with a transient loss of bone mineral density (BMD) during 3-6 months post-partum. Bone changes during lactation in women consuming low dietary calcium are not sufficiently studied. The present longitudinal study examined the BMD changes during lactation in undernourished women and the relationship of bone changes to the nutritional status. Whole-body bone mineral content and BMD at hip, lumbar spine and forearm were assessed using dual-energy X-ray absorptiometry in thirty-six lactating women from the low socio-economic group at four time points -- within 1 month after delivery (baseline), and at 6, 12 and 18 months after delivery. Maternal body composition and biochemical parameters of bone metabolism were estimated at the same time. It was observed that femoral neck BMD reduced by 4.6 % at 6 months, but recovery to the baseline was incomplete at 18 months with a deficit of 2 %. Hip BMD reduction at 6 months was transient. Lumbar spine BMD did not show significant loss at 6 months and BMD increased by 3.6 and 6.3 % at 12 and 18 months, respectively. Regression analyses indicated that baseline lean mass was the most important determinant of bone preservation at femoral neck, hip as well as whole body, whereas baseline body weight was the most important determinant of per cent gain in lumbar spine. Maternal nutritional status as indicated by body weight and lean mass appears to influence the lactation-related BMD changes in undernourished women from the low socio-economic group in India.
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PMID:Maternal weight and lean body mass may influence the lactation-related bone changes in young undernourished Indian women. 1895 8

Osteoporosis is the leading cause of bone fragility fractures in the elderly population. One-third of women ever 65 will have spine fracture. Hip fracture are of even greater clinical significance. The enormity of this health problem when considering the increasing population of elderly people in Japan is contrasted by the present therapeutic difficulties in improving bone strength. These have resulted in serious considerations of public health assessment to identify elderly people with high fracture risks.
Clin Calcium 2008 Nov
PMID:[Osteoporosis in the diseases of musculoskeletal ambulation disability symptom complex (MADS)]. 1897 44

We previously reported greater than average aBMD in adult Hutterites; however, it is unknown whether higher aBMD occurs at younger ages. We examined Hutterite children to test the hypotheses that aBMD Z-scores in younger (<15 years) Hutterite children would be similar to reference data; but greater in older children after they enter the adult workforce at age 15. A secondary aim was to determine lifestyle factors associated with bone measures among Hutterite children. Hip, femoral neck, and spine BMC and aBMD were measured in 323 Hutterite children aged 8 through 19 years: 186 (108 girls) were <15 years (younger) and 137 (87 girls) were >or=15 years (older). Anthropometric measurements and activity and dietary recalls were obtained. Overall, children were lighter (Z=-0.29+/-0.72 [mean+/-SD]), shorter (Z=-0.15+/-0.86, and had lower BMI's (Z=-0.27+/-0.70) than other South Dakota children residing in the same counties (all, p<or=0.002). Older girls and boys had higher percent time in moderate+vigorous activity (21+/-10% and 29+/-11% [mean+/-SD]) than younger girls and boys (15+/-10% and 18+/-10%, both p<0.001). Younger girls and boys had high hip aBMD Z-scores (0.30+/-1.0, 0.44+/-0.97; both greater than 0 at p<or=0.002). Younger males had low spine Z-score (-0.27+/-1.15, p=0.04). None of the Z-scores for the older ages were different from 0. Controlling for covariates, miles walked/day and grip strength were associated with greater hip bone area among girls (both, p<0.05). Grip strength was associated with hip and femoral neck BMC and hip aBMD among boys (all, p<0.05). Femoral neck bone area was inversely associated with calcium intake among boys (p<or=0.05), while higher hip BMC and spine BMC and aBMD were associated with increased vitamin D intake (all, p<or=0.05). Lean mass was an independent predictor of all bone measures, while fat mass was inversely associated with most measures of bone area. In summary, contrary to our hypothesis younger Hutterite children had greater hip aBMD Z scores than the normative DXA database, whereas older children did not. We speculate that high activity levels during the rapid growth phase leads to increased bone turnover and bone size; following bone consolidation later in young adulthood this will result in greater bone size and aBMD.
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PMID:High bone density in young Hutterite children. 1909 89

Bisphosphonate is highly potent antiresorptive agent with an effect to preserve bone structure. Structural property is evaluated using bone imaging techniques. Hip Structure Analysis (HSA) program based on 2D hip DXA data, estimates 3D geometrical properties such as cross-sectional area (CSA) , subperiosteal width and average cortical thickness. From these geometrical parameters, biomechanical indices can be derived. HSA shows BP has an effect to prevent of endocortical resorption and to increase cortical thickness, and finally to increase biomechanical strength. Micro-CT visualizes and measures 3D trabecular microarchitecture, which shows that BP prevents osteoporotic microstructural deterioration, such as trabecular disconnectivity, decrease of trabecular number, and transformation from plate-like structure to rod-like structure. These changes are considered to be related to increase biomechanical strength.
Clin Calcium 2009 Jan
PMID:[New development in bisphosphonate treatment. Effect of bisphosphonate on structural property]. 1912 61

Osteoporosis is a major health issue worldwide, with significant economic consequences and adverse impacts on the quality of life. Hip fractures are the most devastating complication of osteoporosis, are likely to increase exponentially with an increasingly aged population, are associated with high recurrence rate, and lead to significant morbidity and mortality. This review discusses the prevalence and impact of hip fractures, the assessment of fracture risk, fall prevention, and treatment of osteoporosis with emphasis on evidence for hip fracture reduction among the various agents currently available. The aim is to provide recommendations to optimize hip fracture prevention and treatment. Ample evidence exists in the literature of many other risk factors independent from bone mineral density that increase fracture risk. These clinical risk factors have been validated in large cohorts and are incorporated into clinical tools that are invaluable in treatment decisions. In addition, strategies to prevent or reduce falls are integral to comprehensive osteoporosis management. Vitamin D combined with calcium has a role in primary prevention. Alendronate, residronate, strontium and zoledronic acid have proven efficacy in primary and secondary hip fracture prevention. An aggressive approach to investigate, assess and manage an individual's fracture risk and fall risk is paramount to reduce the high morbidity and mortality associated with hip fractures. The choice of therapy should be determined by the patient's calculated fracture risk and efficacy of the potential treatment, including long term compliance associated with the agent of choice.
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PMID:Prevention and treatment of senile osteoporosis and hip fractures. 1927 6

Hip fractures secondary to osteoporosis are common in the elderly. Stabilizing these fractures until union is achieved is a challenge due to poor bone stock and insufficient purchase of the implant to the bone. The reported high rate of complications has prompted extensive research in the development of fixation techniques. Furthermore, manipulation of both the local fracture environment in terms of application of growth factors, scaffolds, and mesenchymal cells and the systemic administration of agents promoting bone formation and bone strength has been considered as a treatment option with promising results. There are only a few evidence-based studies reporting on fixation augmentation techniques. This article reports on the efficacy of bone graft substitutes for the fixation of hip fractures, in particular calcium phosphates, which have been used as granules, cements, and implant coatings.
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PMID:Can we improve fixation and outcomes? Use of bone substitutes. 1955 Feb 28


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