993 resultados para Bone atrophy
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Gastric atrophy is associated with Helicobacter pylori infection. Conflicting results have been obtained as to whether acid suppressant therapy hastens the development or changes the distribution of atrophy in the stomach. The aim of this study was to investigate whether concomitant proton pump inhibitor (PPI) therapy in H. pylori-infected individuals resulted in an increase or an alteration in atrophy distribution and whether this was reflected by the plasma gastrin.
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Atrophic gastritis can develop in patients with Helicobacter pylori infection leading to a reduction in basal acid output. Whether the atrophy that develops is reversible is controversial.
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Background: The effects of subclinical vitamin D deficiency on bone mineral density (BMD) and bone turnover in adolescents, especially in boys, are unclear.
Objective: We aimed to investigate the relations of different stages of vitamin D status and BMD and bone turnover in a representative sample of adolescent boys and girls.
Design: BMD was measured by dual-energy X-ray absorptiometry at the nondominant forearm and dominant heel in a random sample of 12- (n = 260) and 15-y-old (n = 239) boys and 12- (n = 266) and 15-y-old (n = 250) girls. Serum 25-hydroxyvitamin D, parathyroid hormone, osteocalcin, and type I collagen cross-linked C-telopeptide were assessed by using enzyme-linked immunoassays. Relations between vitamin D status and bone health indexes were assessed by using regression modeling.
Results: Using multivariate regression to adjust for potential physical, lifestyle, and dietary confounding factors, we observed that 12-and 15-y-old girls with high vitamin D status (>= 74.1 nmol/L) had significantly greater forearm (but not heel) BMD (beta = 0.018; SE = 0.008; P < 0.05 for each age group) and lower serum parathyroid hormone concentrations and bone turnover markers than did those with low vitamin D status. These associations were evident in subjects sampled throughout the year and in winter only. There was no significant relation between vitamin D status and BMD in boys.
Conclusions: Maintaining serum 25-hydroxyvitamin D concentrations above approximate to 50 nmol/L throughout the year may be a cost-effective means of improving bone health. Increased emphasis on exploring strategies for improving vitamin D status in adolescents is needed.
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Background: Interest in the prevention of osteoporosis is increasing and thus there is a need for an acceptable osteoporosis prevention programme in general practice. AIM. A study was undertaken to identify a cohort of middle-aged women attending a general practice who would be eligible for a longitudinal study looking at bone mineral density, osteoporosis and the effectiveness of hormone replacement therapy. This study aimed to describe the relationship between medical and lifestyle risk factors for osteoporosis and the initial bone density measurements in this group of women. METHOD. A health visitor administered a questionnaire to women aged between 48 and 52 years registered with a Belfast general practice. The main outcome measures were menopausal status, presence of medical and lifestyle risk factors and bone mineral density measurements. RESULTS. A total of 358 women our of 472 (76%) took part in the study which was conducted in 1991 and 1992. A highly significant difference was found between the mean bone mineral density of premenopausal, menopausal and postmenopausal women within the narrow study age range, postmenopausal women having the lowest bone mineral density. A significant relationship was found between body mass index and bone mineral density, a greater bone mineral density being found among women with a higher body mass index. Risk factors such as smoking and sedentary lifestyle were common (reported by approximately one third of respondents) but a poor relationship was found between these two and all the other risk factors and bone mineral density in this age group. CONCLUSION. Risk of osteoporosis cannot be identified by the presence of risk factors in women aged between 48 and 52 years. In terms of a current prevention strategy for general practice it would be better to take a population-based approach except for those women known to be at high risk of osteoporosis: women with early menopause or those who have had an oophorectomy.
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We investigated the phenotype of cells involved in leukostasis in the early stages of streptozotocin-induced diabetes in mice by direct observation and by adoptive transfer of calcein-AM-labeled bone marrow-derived leukocytes from syngeneic mice. Retinal whole mounts, confocal microscopy, and flow cytometry ex vivo and scanning laser ophthalmoscopy in vivo were used. Leukostasis in vivo and ex vivo in retinal capillaries was increased after 2 weeks of diabetes (Hb A(1c), 14.2 ± 1.2) when either donor or recipient mice were diabetic. Maximum leukostasis occurred when both donor and recipient were diabetic. CD11b(+), but not Gr1(+), cells were preferentially entrapped in retinal vessels (fivefold increase compared with nondiabetic mice). In diabetic mice, circulating CD11b(+) cells expressed high levels of CCR5 (P = 0.04), whereas spleen (P = 0.0001) and retinal (P = 0.05) cells expressed increased levels of the fractalkine chemokine receptor. Rosuvastatin treatment prevented leukostasis when both recipient and donor were treated but not when donor mice only were treated. This effect was blocked by treatment with mevalonate. We conclude that leukostasis in early diabetic retinopathy involves activated CCR5(+)CD11b(+) myeloid cells (presumed monocytes). However, leukostasis also requires diabetes-induced changes in the endothelium, because statin therapy prevented leukostasis only when recipient mice were treated. The up-regulation of the HMG-CoA reductase pathway in the endothelium is the major metabolic dysregulation promoting leukostasis.
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Transplantation of hepatocytes or hepatocyte-like cells of extrahepatic origin is a promising strategy for treatment of acute and chronic liver failure. We examined possible utility of hepatocyte-like cells induced from bone marrow cells for such a purpose. Clonal cell lines were established from the bone marrow of two different rat strains. One of these cell lines, rBM25/S3 cells, grew rapidly (doubling time, approximately 24 hours) without any appreciable changes in cell properties for at least 300 population doubling levels over a period of 300 days, keeping normal diploid karyotype. The cells expressed CD29, CD44, CD49b, CD90, vimentin, and fibronectin but not CD45, indicating that they are of mesenchymal cell origin. When plated on Matrigel with hepatocyte growth factor and fibroblast growth factor-4, the cells efficiently differentiated into hepatocyte-like cells that expressed albumin, cytochrome P450 (CYP) 1A1, CYP1A2, glucose 6-phosphatase, tryptophane-2,3-dioxygenase, tyrosine aminotransferase, hepatocyte nuclear factor (HNF)1 alpha, and HNF4alpha. Intrasplenic transplantation of the differentiated cells prevented fatal liver failure in 90%-hepatectomized rats. In conclusion, a clonal stem cell line derived from adult rat bone marrow could differentiate into hepatocyte-like cells, and transplantation of the differentiated cells could prevent fatal liver failure in 90%-hepatectomized rats. The present results indicate a promising strategy for treating human fatal liver diseases.
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We had previously demonstrated the participation of whole bone marrow cells from adult mice in the reconstitution of skin, including the epidermis and hair follicles. To get an insight into cell populations that give rise to the epithelial components of the reconstituted skin, we fractionated bone marrow cells derived from green fluorescent protein-transgenic mice by density gradient. Unexpectedly, we found that a substantial amount of mononucleated cells (approximately 30%) was recovered in the pellet fraction and that the cells in the pellet fraction preferentially differentiated into epithelial components of skin, rather than the cells in the mononuclear cell fraction. The pellet fraction contained more CD45-negative (thus uncommitted to the hematopoietic cell lineage) cells than the mononuclear cell fraction. These results indicate that density gradient fractionation results in significant loss of specific progenitor cells into the usually discarded pellet fraction.
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BACKGROUND: Patients with castration-resistant prostate cancer (CRPC) and bone metastases have an unmet clinical need for effective treatments that improve quality of life and survival with a favorable safety profile. OBJECTIVE: To prospectively evaluate the efficacy and safety of three different doses of radium chloride (Ra 223) in patients with CRPC and bone metastases. DESIGN, SETTING, AND PARTICIPANTS: In this phase 2 double-blind multicenter study, 122 patients were randomized to receive three injections of Ra 223 at 6-wk intervals, at doses of 25 kBq/kg (n=41), 50 kBq/kg (n=39), or 80 kBq/kg (n=42). The study compared the proportion of patients in each dose group who had a confirmed decrease of =50% in baseline prostate-specific antigen (PSA) levels. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Efficacy was evaluated using blood samples to measure PSA and other tumor markers, recorded skeletal-related events, and pain assessments. Safety was evaluated using adverse events (AEs), physical examination, and clinical laboratory tests. The Jonckheere-Terpstra test assessed trends between groups. RESULTS AND LIMITATIONS: The study met its primary end point with a statistically significant dose-response relationship in confirmed =50% PSA declines for no patients (0%) in the 25-kBq/kg dose group, two patients (6%) in the 50-kBq/kg dose group, and five patients (13%) in the 80-kBq/kg dose group (p=0.0297). A =50% decrease in bone alkaline phosphatase levels was identified in six patients (16%), 24 patients (67%), and 25 patients (66%) in the 25-, 50-, and 80-kBq/kg dose groups, respectively (p
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ABSTRACT: Bone-seeking radionuclides including samarium-153 ethylene diamine tetramethylene phosphonate and strontium-89 have been used for decades in the palliation of pain from bone metastases especially from prostate cancer. Emerging evidence of improved survival in metastatic castration-resistant prostate cancer (CRPC) with the first-in-class a-radionuclide, radium-223 (Ra) has rekindled interest in the role of bone-seeking radionuclide therapy.We review the literature for randomized controlled trials of bone-seeking radionuclides and explore some of the issues regarding the optimal use of these agents. In particular, we discuss dose, dose rate, radiobiology, and quality of radiation and postulate on potential future directions in particular combination schedules. ß-Emitting, bone-seeking radionuclides have proven ability to control pain in prostate cancer metastatic to bone with pain response rates in the order of 60% to 70% when used as single agents. Most of the published trials were underpowered to detect differences in survival; however, there is evidence of the potential for disease modification when these agents are used in combination with chemotherapy or in multiple cycles.Data from the recent phase III ALSYMPCA trial that compared Ra to placebo in symptomatic CRPC demonstrate a significant improvement in median overall survival of 3.6 months for patients with symptomatic CRPC metastatic to bone treated with 6 cycles of the a-emitting radionuclide Ra compared with placebo. The success of Ra in improving survival in CRPC will lead this agent to become part of the treatment paradigm for this disease, and with such an excellent safety profile, Ra has huge potential in combination strategies as well as for use earlier in the natural history of metastatic prostate cancer.
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Purpose: To describe the occurrence of geographic atrophy in patients with retinal angiomatous proliferation (RAP). Methods: Demographics, visual acuity, color fundus photographs, fluorescein and indocyanine green angiograms, and fundus autofluorescence and near-infrared autofluorescence images were reviewed in 53 patients (66 eyes) with RAP. Results: Of 53 treatment-naive eyes, 19 (36%) had atrophy at baseline. Of 66 eyes, 57 (86%) developed de novo atrophy or enlargement of preexisting areas of atrophy during the follow-up (median, 17 months; range, 3-53 months) after treatment. Areas of atrophy were observed at the site of the RAP (58 of 66 eyes, 88%) of a previously existing pigment epithelial detachment (18 of 44 eyes; 41%) and elsewhere (43 of 66 eyes, 65%). At presentation, RAP was found to be frequently associated with increased autofluorescence at the fovea because of cystoid macular edema (36 of 53 eyes, 68%) and reduced autofluorescence because of hard exudation (38 of 53 eyes, 72%) and intraretinal hemorrhages (32 of 53 eyes, 60%). Background reticular (39%) and homogeneous (36%) autofluorescence were most commonly observed. Conclusion: Geographic atrophy occurs frequently in patients with RAP after treatment. This information, if confirmed in other cohorts, would be valuable for the counseling of patients with this disease and for the understanding of the pathogenesis of this condition and its progression after treatment. Copyright © 2011 Lippincott Williams &Wilkins.
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PURPOSE:: To evaluate the occurrence of retinal pigment epithelial atrophy in patients with age-related macular degeneration undergoing anti-vascular endothelial growth factor therapy. METHODS:: The study is a retrospective review. Eligible were patients with age-related macular degeneration and choroidal neovascular membranes treated with anti-vascular endothelial growth factor between October 2007 and February 2011; they were followed for >3 months, with fundus photographs and fluorescein angiography at baseline and with autofluorescence and near-infrared autofluorescence images at baseline and follow-up. Demographics, visual acuity, the type of choroidal neovascular membranes, the number of treatments performed, and the length of follow-up were recorded. Autofluorescence and near-infrared autofluorescence images were evaluated for the presence or absence of areas of reduced signal. A multilevel logistic regression model was used to investigate the factors that may be associated with progression of atrophy at follow-up, which was the primary outcome of this study. RESULTS:: Sixty-three patients (72 eyes) were followed for a median of 16 months (range, 3-36 months). Atrophy at baseline was observed in 47% (34/72) of eyes; progression of atrophy occurred in 62% (45/72) of eyes at the last visit. The number of anti-vascular endothelial growth factor injections received was statistically significantly associated with the progression of atrophy at follow-up (odds ratio, 1.35; 95% confidence interval, 1.05-1.73; P = 0.02). CONCLUSION:: Atrophy was frequently observed in patients with age-related macular degeneration and choroidal neovascular membranes undergoing anti-vascular endothelial growth factor therapy.
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• PURPOSE: To evaluate retinal pigment epithelial (RPE) atrophy in patients with Stargardt disease using autofluorescence imaging (AF). • DESIGN: Retrospective observational case series. • METHODS: Demographics, best-corrected visual acuity (BCVA), AF images, and electrophysiology responses (group 1, macular dysfunction; group 2, macula + cone dysfunction; group 3, macula + cone-rod dysfunction) were evaluated at presentation and follow-up in a group of 12 patients (24 eyes) with Stargardt disease. The existence, development, and rate of enlargement of areas of RPE atrophy over time were evaluated using AF imaging. A linear regression model was used to investigate the effects of AF and electrophysiology on rate of atrophy enlargement and BCVA, adjusting for age of onset and duration of disease. • RESULTS: Eight male and 4 female patients (median age 42 years; range 24-69 years) were followed for a median of 41.5 months (range 13-66 months). All 12 patients had reduced AF compatible with RPE atrophy at presentation and in all patients the atrophy enlarged during follow-up. The mean rate of atrophy enlargement for all patients was 1.58 mm /y (SD 1.25 mm /y; range 0.13-5.27 mm /y). Only the pattern of functional loss present as detected by electrophysiology was statistically significantly associated with the rate of atrophy enlargement when correcting for other variables (P <.001), with patients in group 3 (macula + cone-rod dysfunction) having the fastest rate of atrophy enlargement (1.97 mm /y, SD 0.70 mm /y) (group 1 [macula] 1.09 mm /y, SD 0.53 mm /y; group 2 [macula + cone] 1.89 mm /y, SD 2.27 mm /y). • CONCLUSION: Variable rates of atrophy enlargement were observed in patients with Stargardt disease. The pattern of functional loss detected on electrophysiology was strongly associated with the rate of atrophy enlargement over time, thus serving as the best prognostic indicator for patients with this inherited retinal disease. © 2012 Elsevier Inc. All rights reserved.
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Conflicting results have been reported on the detection of paramyxovirus transcripts in Paget's disease, and a possible explanation is differences in the sensitivity of RT-PCR methods for detecting virus. In a blinded study, we found no evidence to suggest that laboratories that failed to detect viral transcripts had less sensitive RT-PCR assays, and we did not detect measles or distemper transcripts in Paget's samples using the most sensitive assays evaluated.
Introduction: There is conflicting evidence on the possible role of persistent paramyxovirus infection in Paget's disease of bone (PDB). Some workers have detected measles virus (MV) or canine distemper virus (CDV) transcripts in cells and tissues from patients with PDB, but others have failed to confirm this finding. A possible explanation might be differences in the sensitivity of RT-PCR methods for detecting virus. Here we performed a blinded comparison of the sensitivity of different RT-PCR-based techniques for MV and CDV detection in different laboratories and used the most sensitive assays to screen for evidence of viral transcripts in bone and blood samples derived from patients with PDB.
Materials and Methods: Participating laboratories analyzed samples spiked with known amounts of MV and CDV transcripts and control samples that did not contain viral nucleic acids. All analyses were performed on a blinded basis.
Results: The limit of detection for CDV was 1000 viral transcripts in three laboratories (Aberdeen, Belfast, and Liverpool) and 10,000 transcripts in another laboratory (Manchester). The limit of detection for MV was 16 transcripts in one laboratory (NIBSC), 1000 transcripts in two laboratories (Aberdeen and Belfast), and 10,000 transcripts in two laboratories (Liverpool and Manchester). An assay previously used by a U.S.-based group to detect MV transcripts in PDB had a sensitivity of 1000 transcripts. One laboratory (Manchester) detected CDV transcripts in a negative control and in two samples that had been spiked with MV. None of the other laboratories had false-positive results for MV or CDV, and no evidence of viral transcripts was found on analysis of 12 PDB samples using the most sensitive RT-PCR assays for MV and CDV.
Conclusions: We found that RT-PCR assays used by different laboratories differed in their sensitivity to detect CDV and MV transcripts but found no evidence to suggest that laboratories that previously failed to detect viral transcripts had less sensitive RT-PCR assays than those that detected viral transcripts. False-positive results were observed with one laboratory, and we failed to detect paramyxovirus transcripts in PDB samples using the most sensitive assays evaluated. Our results show that failure of some laboratories to detect viral transcripts is unlikely to be caused by problems with assay sensitivity and highlight the fact that contamination can be an issue when searching for pathogens by sensitive RT-PCR-based techniques.
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Previous studies have shown that CCL2/CX3CR1 deficient mice on C57BL/6N background (with rd8 mutation) have an early onset (6 weeks) of spontaneous retinal degeneration. In this study, we generated CCL2(-/-)CX3CR1(GFP/GFP) mice on the C57BL/6J background. Retinal degeneration was not detected in CCL2(-/-)CX3CR1(GFP/GFP) mice younger than 6 months. Patches of whitish/yellowish fundus lesions were observed in 17~60% of 12-month, and 30~100% of 18-month CCL2(-/-)CX3CR1(GFP/GFP) mice. Fluorescein angiography revealed no choroidal neovascularisation in these mice. Patches of retinal pigment epithelium (RPE) and photoreceptor damage were detected in 30% and 50% of 12- and 18-month CCL2(-/-)CX3CR1(GFP/GFP) mice respectively, but not in wild-type mice. All CCL2(-/-)CX3CR1(GFP/GFP) mice exposed to extra-light (~800lux, 6 h/day, 6 months) developed patches of retinal atrophy, and only 20-25% of WT mice which underwent the same light treatment developed atrophic lesions. In addition, synaptophysin expression was detected in the outer nucler layer (ONL) of area related to photoreceptor loss in CCL2(-/-)CX3CR1(GFP/GFP) mice. Markedly increased rhodopsin but reduced cone arrestin expression was observed in retinal outer layers in aged CCL2(-/-)CX3CR1(GFP/GFP) mice. GABA expression was reduced in the inner retina of aged CCL2(-/-)CX3CR1(GFP/GFP) mice. Significantly increased Müller glial and microglial activation was observed in CCL2(-/-)CX3CR1(GFP/GFP) mice compared to age-matched WT mice. Macrophages from CCL2(-/-)CX3CR1(GFP/GFP) mice were less phagocytic, but expressed higher levels of iNOS, IL-1ß, IL-12 and TNF-a under hypoxia conditions. Our results suggest that the deletions of CCL2 and CX3CR1 predispose mice to age- and light-mediated retinal damage. The CCL2/CX3CR1 deficient mouse may thus serve as a model for age-related atrophic degeneration of the RPE, including the dry type of macular degeneration, geographic atrophy.
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Results of recent studies have indicated that bone marrow cells can differentiate into various cells of ectodermal, mesodermal, and endodermal origins when transplanted into the body. However, the problems associated with those experiments such as the long latent period, rareness of the event, and difficulty in controlling the processes have hampered detailed mechanistic studies. In the present study, we examined the potency of mouse bone marrow cells to differentiate into cells comprising skin tissues using a skin reconstitution assay. Bone marrow cells from adult green fluorescent protein (GFP)-transgenic mice were transplanted in a mixture of embryonic mouse skin cells (17.5 days post-coitus) onto skin defects made on the backs of nude mice. Within 3 weeks, fully differentiated skin with hair was reconstituted. GFP-positive cells were found in the epidermis, hair follicles, sebaceous glands, and dermis. The localization and morphology of the cells, results of immunohistochemistry, and results of specific staining confirmed that the bone marrow cells had differentiated into epidermal keratinocytes, sebaceous gland cells, follicular epithelial cells, dendritic cells, and endothelial cells under the present conditions. These results indicate that this system is suitable for molecular and cellular mechanistic studies on differentiation of stem cells to various epidermal and dermal cells.