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1.
Background/aim
In a previous study we showed that mandibular alveolar (trabecular) bone appears to be less sensitive to estrogen deficiency than the proximal tibia spongiosa. We hypothesized that the mechanical loading of the alveolar process during mastication may protect the alveolar bone from the detrimental effects observed in other skeletal sites. To test this hypothesis we compared the effect of ovariectomy on the mandibular alveolar bone and the proximal tibia spongiosa of rats fed either a normal (hard) or a soft diet.Methods
Forty six-month-old female Sprague–Dawley rats underwent trans-abdominal ovariectomy (OVX) or sham operation (SHAM). Half of the animals received their food in the usual form of pellets (hard consistency), while the other half received a soft, porridge-like, isocaloric diet of identical composition (soft consistency). Micro-computed tomographic histomorphometry was used to evaluate the trabecular micro-architecture. A two-factor analysis of variance was used to test for effects and interaction of ovariectomy and/or soft diet.Results
OVX had a significantly negative effect on the proximal tibia spongiosa (all parameters under study except trabecular thickness; p<0.001) and on the mandibular alveolar bone (trabecular number and spacing; p<0.05). Soft diet led to a further decrease of mandibular BV/TV (p<0.01), trabecular thickness (p<0.05) and number (p<0.05), as well as increase of separation (p<0.001). A significant interaction was observed between OVX and soft diet concerning the mandibular BV/TV, as well as trabecular thickness and spacing (p<0.05).Conclusion
Normal (hard) diet limited significantly the negative effects of estrogen deficiency on mandibular alveolar bone micro-architecture four months after ovariectomy. 相似文献2.
Yuchen Guo Ningyuan Sun Xiaobo Duan Xin Xu Liwei Zheng Dutmanee Seriwatanachai Yongyue Wang Quan Yuan 《PloS one》2016,11(2)
Background
Chronic kidney disease (CKD) has been regarded as a grave public health problem. Estrogen is a critical factor for both renal protection and bone remodeling. Our previous study demonstrated that CKD impairs the healing of titanium implants. The aim of this study was to investigate the effects of estrogen deficiency on the mandibular bone in CKD mice.Methods
Forty eleven-week-old female C57BL mice were used in this study. Uremia and estrogen deficiency were induced by 5/6 nephrectomy and ovariectomy (OVX), respectively. After 8 weeks, the mice were sacrificed, and their mandibles were collected for micro-CT analysis and histological examination.Results
All the mice survived the experimental period. Serum measurements confirmed a significant increase in BUN in the CKD group that was further increased by OVX. OVX led to significant decreases in both the BV/TV and cortical thickness of the mandibular bone in CKD mice.Conclusion
In summary, our findings indicate that estrogen deficiency leads to further mandibular bone loss in CKD mice. 相似文献3.
Purpose
Collagen peptides (CPs) and calcium citrate are commonly used as bone health supplements for treating osteoporosis. However, it remains unknown whether the combination of oral bovine CPs with calcium citrate is more effective than administration of either agent alone.Methods
Forty 12-week-old Sprague-Dawley rats were randomly divided into five groups (n = 8) for once-daily intragastric administration of different treatments for 3 months at 3 months after ovariectomy (OVX) as follows: sham + vehicle; OVX + vehicle; OVX + 750 mg/kg CP; OVX + CP-calcium citrate (75 mg/kg); OVX + calcium citrate (75 mg/kg). After euthanasia, the femurs were removed and analyzed by dual energy X-ray absorptiometry and micro-computed tomography, and serum samples were analyzed for bone metabolic markers.Results
OVX rats supplemented with CPs or CP-calcium citrate showed osteoprotective effects, with reductions in the OVX-induced decreases in their femoral bone mineral density. Moreover, CP-calcium citrate prevented trabecular bone loss, improved the microarchitecture of the distal femur, and significantly inhibited bone loss with increased bone volume, connectivity density, and trabecular number compared with OVX control rats. CP or CP-calcium citrate administration significantly increased serum procollagen type I N-terminal propeptide levels and reduced serum bone-specific alkaline phosphatase, osteocalcin, and C-telopeptide of type I collagen levels.Conclusions
Our data indicate that combined oral administration of bovine CPs with calcium citrate inhibits bone loss in OVX rats. The present findings suggest that combined oral administration of bovine CPs with calcium citrate is a promising alternative for reducing bone loss in osteopenic postmenopausal women. 相似文献4.
Murali Ravoori Aneta J. Czaplinska Charles Sikes Lin Han Evan M. Johnson Wei Qiao Chaan Ng Dianna D. Cody William A. Murphy Jr Kim-Anh Do Nora M. Navone Vikas Kundra 《PloS one》2010,5(3)
Background
To compare nondestructive in vivo and ex vivo micro-computed tomography (μCT) and ex vivo dual-energy-X-ray-absorptiometry (DXA) in characterizing mineralized cortical and trabecular bone response to prostate cancer involving the skeleton in a mouse model.Methodology/Principal Findings
In vivo μCT was performed before and 10 weeks after implantation of human prostate cancer cells (MDA-PCa-2b) or vehicle into SCID mouse femora. After resection, femora were imaged by nondestructive ex vivo specimen μCT at three voxel sizes (31 µ, 16 µ, 8 µ) and DXA, and then sectioned for histomorphometric analysis of mineralized bone. Bone mineral density (BMD), trabecular parameters (number, TbN; separation, TbSp; thickness, TbTh) and mineralized bone volume/total bone volume (BV/TV) were compared and correlated among imaging methods and histomorphometry. Statistical tests were considered significant if P<0.05. Ten weeks post inoculation, diaphyseal BMD increased in the femur with tumor compared to the opposite femur by all modalities (p<0.005, n = 11). Diaphyseal BMD by in vivo μCT correlated with ex vivo 31 and 16 µm μCT and histomorphometry BV/TV (r = 0.91–0.94, P<0.001, n = 11). DXA BMD correlated less with bone histomorphometry (r = 0.73, P<0.001, n = 11) and DXA did not distinguish trabeculae from cortex. By in vivo and ex vivo μCT, trabecular BMD decreased (P<0.05, n = 11) as opposed to the cortex. Unlike BMD, trabecular morphologic parameters were threshold-dependent and when using “fixed-optimal-thresholds,” all except TbTh demonstrated trabecular loss with tumor and correlated with histomorphometry (r = 0.73–0.90, P<0.05, n = 11).Conclusions/Significance
Prostate cancer involving the skeleton can elicit a host bone response that differentially affects the cortex compared to trabeculae and that can be quantified noninvasively in vivo and nondestructively ex vivo. 相似文献5.
Andrew N. Luu Lorenzo Anez-Bustillos Shima Aran Francisco J. Araiza Arroyo Vahid Entezari Claudio Rosso Brian D. Snyder Ara Nazarian 《PloS one》2013,8(12)
Background
High resolution μCT, and combined μPET/CT have emerged as non-invasive techniques to enhance or even replace dual energy X-ray absorptiometry (DXA) as the current preferred approach for fragility fracture risk assessment. The aim of this study was to assess the ability of µPET/CT imaging to differentiate changes in rat bone tissue density and microstructure induced by metabolic bone diseases more accurately than current available methods.Methods
Thirty three rats were divided into three groups of control, ovariectomy and vitamin-D deficiency. At the conclusion of the study, animals were subjected to glucose (18FDG) and sodium fluoride (Na18F) PET/CT scanning. Then, specimens were subjected to µCT imaging and tensile mechanical testing.Results
Compared to control, those allocated to ovariectomy and vitamin D deficiency groups showed 4% and 22% (significant) increase in 18FDG uptake values, respectively. DXA-based bone mineral density was higher in the vitamin D deficiency group when compared to the other groups (cortical bone), yet μCT-based apparent and mineral density results were not different between groups. DXA-based bone mineral density was lower in the ovariectomy group when compared to the other groups (cancellous bone); yet μCT-based mineral density results were not different between groups, and the μCT-based apparent density results were lower in the ovariectomy group compared to the other groups.Conclusion
PET and micro-CT provide an accurate three-dimensional measurement of the changes in bone tissue mineral density, as well as microstructure for cortical and cancellous bone and metabolic activity. As osteomalacia is characterized by impaired bone mineralization, the use of densitometric analyses may lead to misinterpretation of the condition as osteoporosis. In contrast, µCT alone and in combination with the PET component certainly provides an accurate three-dimensional measurement of the changes in both bone tissue mineral density, as well as microstructure for cortical and cancellous bone and metabolic activity. 相似文献6.
Guo-Xian Chen Shuai Zheng Shuai Qin Zhao-Ming Zhong Xiu-Hua Wu Zhi-Ping Huang Wei Li Ruo-Ting Ding Hui Yu Jian-Ting Chen 《PloS one》2014,9(5)
Background
Alendronate (ALE) is a conventional drug used to treat osteoporosis. Low-magnitude whole-body vibration (WBV) exercise has been developed as a potential treatment for osteoporosis. The aim of this study was to investigate whether low-magnitude WBV could enhance the protective effect of ALE on bone properties in ovariectomized rats.Methods
A total of 128 Sprague-Dawley rats were randomly divided into five groups (SHAM, OVX+VEH, OVX+WBV, OVX + ALE, OVX+WBV+ALE). The level of WBV applied was 0.3 g at 45–55 Hz for 20 min/day, 5 day/week and for 3 months. ALE was administered in dose of 1 mg/Kg once a week. Every four weeks eight rats from each group were sacrificed and their blood and both tibiae were harvested. The expression of osteocalcin and CTX in serum was measured by enzyme-linked immunosorbent assay (ELISA) and the tibiae were subjected to metaphyseal three-point bending and μCT analysis.Results
Osteocalcin rose after ovariectomy and was not appreciably changed by either alendronate or WBV alone or in combination. Alendronate treatment significantly prevented an increase in CTX. WBV alone treatment did not alter this effect. Compared with the OVX+WBV group, nearly all tested indices such as the BV/TV, TV apparent, Tb.N, Tb.Th, and Conn.D were higher in the OVX+ALE group at week 12.Compared with the OVX+WBV group, certain tested indices such as BV/TV, TV apparent, Tb.N, and Con.D, were higher in the OVX+WBV+ALE group at week 12. At week 12, tibiae treated with WBV+ALE exhibited a significantly higher Fmax compared to the OVX+VEH group, and a significant difference was also found in energy absorption between the OVX+WBV+ALE and OVX+VEH groups.Conclusions
Compared with the WBV, ALE was more effective at preventing bone loss and improved the trabecular architecture. However, WBV enhanced the effect of alendronate in ovariectomized rats by inducing further improvements in trabecular architecture. 相似文献7.
Kanokporn Chaiklang Jiraprapa Wipasa Romanee Chaiwarith Jutarat Praparattanapan Khuanchai Supparatpinyo 《PloS one》2013,8(11)
Background
HBV vaccination is recommended in HIV-infected adults with CD4+ cell count >200/mm3 although the efficacy is only 33.3% -65%. We conducted a randomized, controlled trial to evaluate the efficacy and safety of three regimens of HBV vaccination at Chiang Mai University Hospital, Thailand.Methods
From February 4, 2011 to May 4, 2012, 132 HIV-infected adults with CD4+ cell counts >200 cells/mm3, undetectable plasma HIV-1 RNA, and negative for all HBV markers were randomly assigned to receive one of three recombinant vaccine (Hepavax-Gene® Berna, Korea) regimens: 20 μg IM at months 0, 1, and 6 (Standard doses group, n=44), 20 μg IM at months 0, 1, 2, 6 (four doses group, n=44), or 40 μg IM at months 0, 1, 2, and 6 (four double doses group, n=44). The primary outcomes were to compare the immunogenicity and safety between the four-doses groups with the Standard doses group.Results
At months 7 and 12, the percentages of responders (anti-HBs ≥10 mIU/mL) were 88.6% and 70.4% in the Standard doses group, 93.2% and 86.4% in the four doses group, (P=0.713 and 0.119), and 95.4% and 88.6% in the four double doses group, (P=0.434 and 0.062), respectively. Factors associated with a high titer level (anti-HBs ≥100 mIU/mL) were vaccination schedule and younger age. The most common adverse event was pain at the injection site (42.4%); this was significantly more frequent in the four double doses group compared to the Standard doses group. No serious adverse events were observed.Conclusions
In Northern Thailand, the standard three-doses HBV vaccination in HIV-infected adults with CD4+ cell counts >200 cells/mm3 and undetectable plasma HIV-1 RNA is highly effective. Although regimens of four injections of either standard or double doses could not significantly increase the response rate, these regimens may induce higher levels of antibody to the virus.Trial registration information: ClinicalTrials.gov; NCT1289106; http://clinicaltrials.gov/ct2/show/NCT01289106 相似文献8.
Background
Feline infectious peritonitis (FIP) is a lethal immune-mediated disease caused by feline coronavirus (FCoV). Currently, no therapy with proven efficacy is available. In searching for agents that may prove clinically effective against FCoV infection, five analogous overlapping peptides were designed and synthesized based on the putative heptad repeat 2 (HR2) sequence of the spike protein of FCoV, and the antiviral efficacy was evaluated.Methods
Plaque reduction assay and MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) cytotoxicity assay were performed in this study. Peptides were selected using a plaque reduction assay to inhibit Feline coronavirus infection.Results
The results demonstrated that peptide (FP5) at concentrations below 20 μM inhibited viral replication by up to 97%. The peptide (FP5) exhibiting the most effective antiviral effect was further combined with a known anti-viral agent, human interferon-α (IFN-α), and a significant synergistic antiviral effect was observed.Conclusion
Our data suggest that the synthetic peptide FP5 could serve as a valuable addition to the current FIP prevention methods. 相似文献9.
Barry S. Peters Melissa Perry Anthony S. Wierzbicki Lisa E. Wolber Glen M. Blake Nishma Patel Richard Hoile Alastair Duncan Ranjababu Kulasegaram Frances M. K. Williams 《PloS one》2013,8(10)
Objective
To determine comparative fracture risk in HIV patients compared with uninfected controls.Design
A randomised cross-sectional study assessing bone mineral density (BMD), fracture history and risk factors in the 2 groups.Setting
Hospital Outpatients.Subbbjects
222 HIV infected patients and an equal number of age-matched controls. Assessments: Fracture risk factors were assessed and biochemical, endocrine and bone markers measured. BMD was assessed at hip and spine. 10-year fracture probability (FRAX) and remaining lifetime fracture probability (RFLP) were calculated.Main Outcome Measures
BMD, and history of fractures.Results
Reported fractures occurred more frequently in HIV than controls, (45 vs. 16; 20.3 vs. 7%; OR=3.27; p=0.0001), and unsurprisingly in this age range, non-fragility fractures in men substantially contributed to this increase. Osteoporosis was more prevalent in patients with HIV (17.6% vs. 3.6%, p<0.0001). BMD was most reduced, and predicted fracture rates most increased, at the spine. Low BMD was associated with antiretroviral therapy (ART), low body mass index and PTH. 10-year FRAX risk was <5% for all groups. RLFP was greater in patients with HIV (OR=1.22; p=0.003) and increased with ART (2.4 vs. 1.50; OR= 1.50; p=0.03).Conclusions
The increased fracture rate in HIV patients in our relatively youthful population is partly driven by fractures, including non-fragility fractures, in men. Nonetheless, these findings may herald a rise in osteoporotic fractures in HIV patients. An appropriate screening and management response is required to assess these risks and identify associated lifestyle factors that are also associated with other conditions such as cardiovascular disease and diabetes. 相似文献10.
Background
Iodine deficiency disorders (IDD) are widespread in China. Presently, IDD have been put under control by Universal Salt Iodisation (USI) in China; however, there is a lack of evidence on whether the iodine status in adults, pregnant women and lactating women is optimal. This study was therefore conducted to assess the iodine nutrition and thyroid function of children, adults, pregnant women and lactating women residing in areas where the USI program is fully established.Design
Six areas were selected according to the geographical regions in China. In each of these areas, we selected 4 distinct groups of subjects (children, adults, pregnant women and lactating women) in regions where the coverage rate of iodised salt was more than 95% and the levels of iodine and fluoride in drinking water were less than or equal to 10 µg/L and 1 mg/L, respectively. We tested the iodine content of salt, urinary iodine (UI), free thyroxin (FT4), thyrotropin (TSH), thyroglobulin (Tg), thyroglobulin antibody (Tg-Ab) and antimicrosomal antibody (TM-Ab) in the 4 groups, and examined the thyroid volume in children.Results
The median urinary iodine (MUI) concentrations were 271.4 μg/L, 260.2 μg/L, 205.9 μg/L and 193.9 μg/L in children, adults, pregnant women and lactating women, respectively; MUI in children and adults were more than adequate. The goitre prevalence (GP) in children was 6.70%. The odds ratios (OR) of subclinical hypothyroidism in the Tg-Ab- or TM-Ab-positive groups were 3.80, 7.65, 2.01 and 7.47 for children, adults, pregnant women and lactating women, respectively, compared with the negative groups.Conclusions
The iodine status in children and adults is above the requirement, we should reduce their iodine intake. Subclinical hypothyroidism easily occurs in the Tg-Ab or TM-Ab positive groups. 相似文献11.
目的:动态观察去卵巢大鼠腰椎骨微结构的变化。方法:将90只3月龄雌性SD大鼠按体重进行分层随机抽样分组,分为基础组(10只)、假手术组(40只)和去卵巢组(40只)。手术前(0周)处死基础组大鼠,手术后3、6、12、24周时,分批处死假手术和去卵巢组大鼠各8-10只。从每组随机取6只大鼠的第5腰椎行micro-CT扫描及三维结构重建,选取椎体1 mm处,2.0 mm×3.5mm,厚0.9 mm的骨组织为感兴趣区域(interesting area),进行骨形态计量学分析。结果:与同一时间点假手术组大鼠比较,去卵巢3周时,第5腰椎体积骨密度(v BMD)、骨体积分数(BV/TV)、骨小梁数目(Tb.N)、骨小梁厚度(Tb.Th)、骨小梁间隙(Tb.Sp)和结构模型指数(SMI)均无显著变化;去卵巢6周时,Tb.Th显著下降(P0.05),而其他指标均无显著变化;从去卵巢12周到24周时,不仅Tb.Th显著下降(P0.05),而且v BMD、BV/TV和Tb.N也显著下降(P0.05),同时Tb.Sp和SMI显著增加(P0.05)。结论:3月龄大鼠在去卵巢后的6周时骨小梁厚度变薄,12周以后,体积骨密度和骨体积分数下降,骨小梁数目减少。 相似文献
12.
Xiongliang Zhang Xiaoyu Yan Liang Cheng Jiezhi Dai Chunyang Wang Pei Han Yimin Chai 《PloS one》2013,8(12)
Background
Hypoxia-inducible factor 1α is the central regulator of the hypoxia-induced response which results in the up-regulation of angiogenic factors. Its activity is under precise regulation of prolyl-hydroxylase domain 2. We hypothesized that PHD2 silenced fibroblasts would increase the expression of angiogenic factors, which might contribute to the improvement of the diabetic wound healing.Materials and Methods
50 dB/db mice were employed and randomly assigned into five groups with 10 mice in each: group 1 (untreated cell), group 2 (PHD2 silenced cell), group 3 (L-mimosine treated cells), group 4 (nontargeting siRNA treated cells) and group 5 (sham control). Fibroblasts were cultivated from the dermis of mice in each group and treated with PHD2 targeting siRNA, L-mimosine and non-targeting siRNA respectively. A fraction of the fibroblasts were employed to verify the silencing rate of PHD2 after 48 hours. The autologous fibroblasts (treated and untreated) labeled with adenovirus-GFP were implanted around the wound (Φ6mm), which was created on the dorsum of each mouse. The status of wounds was recorded periodically. Ten days postoperatively, 3 mice from each group were sacrificed and wound tissues were harvested. Molecular biological examinations were performed to evaluate the expressions of cytokines. 28 days postoperatively, the remaining mice were sacrificed. Histological examinations were performed to evaluate the densities of GFP+ cells and capillaries.Results
The expression of PHD2 reduced to 12.5%, and the expressions of HIF-1α and VEGFa increased significantly after PHD2 siRNA treatment. With the increasing expressions of HIF-1α and VEGFa, the time to wound closure in group 2 was less than 2 weeks. Increased numbers of GFP+ cells and capillaries were observed in group 2.Conclusion
PHD2 siRNA treatment not only increased the expression of HIF1α and VEGFa, but also improved the fibroblast proliferation. These effects might contribute to the improvement of the diabetic wound healing. 相似文献13.
Background
The effect of age on the bone mineral density and microarchitecture of the equine radius and tibia was investigated. Fifty-six bones from 15 horses aged four to 21 years were used. There were nine geldings and six mares, and none of the horses had any disease influencing bone properties. Xtreme computed tomography was used to evaluate a 9-mm segment of the diaphysis and metaphysis of each bone. The following variables were determined: length of the bone, circumference and diameter in the frontal and sagittal planes in the middle of the bone.Diaphysis: total volume, bone volume, bone volume ratio, slice area, bone area, marrow area, cortical and marrow thickness, bone mineral density, polar moment of inertia of the cortex.Metaphysis: total area, bone area, cortical bone area, cortical thickness, bone mineral density, bone mineral density in the cortex, bone mineral density in the trabecular region, trabecular number, trabecular thickness, trabecular separation, polar moment of inertia of the metaphysis, polar moment of inertia of the cortex of the metaphysis.Results
Bone density and microarchitecture were not affected by breed or gender. However, the microarchitecture varied with the age of the horse; the number of trabeculae decreased significantly and the distance between trabeculae increased significantly with increasing age. There were no significant differences between bones of the left and right limbs or between the radius and tibia.Conclusion
The variables investigated did not differ between geldings and mares. However, there were age-related changes in the microstructure of the bones. Further experimental studies are necessary to determine whether these changes reduce bone strength. Age-related changes in the bones were seen and may explain the higher incidence of fractures and fissures in older horses.14.
C.E. Kawalilak J.D. Johnston W.P. Olszynski S.A. Kontulainen 《Journal of musculoskeletal & neuronal interactions》2015,15(2):190-196
Background:
Least Significant Change (LSC) assists in determining whether observed bone change is beyond measurement precision. Monitoring Time Interval (MTI) estimates time required to reliably detect skeletal changes. MTIs have not been defined for bone outcomes provided by high resolution peripheral quantitative computed tomography (HR-pQCT). The purpose of this study was to determine the LSCs and MTIs for HR-pQCT derived bone area, density and micro-architecture with postmenopausal women.Methods:
Distal radius and tibia of 33 postmenopausal women (mean age: 77, SD: ±7 years), from the Saskatoon cohort of the Canadian Multicentre Osteoporosis Study (CaMos), were measured using HR-pQCT at baseline and 1-year later. We determined LSC from precision errors and divided them by the median annual percent changes to define MTIs for bone area, density, and micro-architecture.Results:
Distal radius: HR-pQCT LSCs indicated a 1-8% observed change was needed for reliable monitoring of bone area and density while a 3-18% change was needed for micro-architectural measures. The longest MTIs (>3 years) pertained to cortical and trabecular area and density measures, cortical thickness and bone volume fraction; the shortest MTIs (~2 years) pertained to bone micro-architectural measures (trabecular number, thickness, separation and heterogeneity). Distal tibia: LSCs indicated a <1-5% observed change was needed for reliable monitoring of bone area and density, while a 3-19% change was needed for micro-architectural measures. The longest MTIs (>3 years) pertained to trabecular density, bone volume fraction, number, separation and heterogeneity; the shortest MTIs (~1 year) pertained to cortical and trabecular area, cortical density and thickness.Conclusion:
MTIs suggest that performing HR-pQCT follow-up measures in postmenopausal women every 2 years at the distal radius and every 1 year at the distal tibia to monitor true skeletal changes as indicated by the LSCs. 相似文献15.
Objective
To observe dynamic changes in root resorption repair, tooth movement relapse and alveolar bone microstructure following the application of orthodontic force.Materials and Methods
Forces of 20 g, 50 g or 100 g were delivered to the left maxillary first molars of fifteen 10-week-old rats for 14 days. Each rat was subjected to micro-computed tomography scanning at 0, 3, 7, 10, 14, 28 and 42 days after force removal. The root resorption crater volume, tooth movement relapse and alveolar bone microarchitecture were measured at each time point.Results
From day 3 to day 14, the root resorption volume decreased significantly in each group. In the 20-g force group, the root resorption volume gradually stabilized after 14 days, whereas in the 50-g and 100-g force groups, it stabilized after 28 days. In all groups, tooth movement relapsed significantly from day 0 to day 14 and then remained stable. From day 3 to day 10, the 20-g group exhibited faster relapse than the 50-g and 100-g groups. In all groups, the structure model index and trabecular separation decreased slowly from day 0 to day 10 and eventually stabilized. Trabecular number increased slowly from day 0 to day 7 and then stabilized.Conclusions
The initial stage of root resorption repair did not change significantly and was followed by a dramatic repair period before stabilizing. The most serious tooth movement relapse occurred immediately after the appliance was removed, and then the tooth completely returned to the original position. 相似文献16.
Rogério da Silva Linhares Denise Petrucci Gigante Fernando Celso Lopes Fernandes de Barros Bernardo Lessa Horta 《PloS one》2015,10(1)
Objective
To examine the relationship between carotid intima-media thickness (IMT) at age 30 and birth characteristics, growth during infancy, and breastfeeding duration, among subjects who have been prospectively followed since birth.Methods and Results
In 1982, all births in the city of Pelotas, southern Brazil, were identified and those children (n = 5,914) whose families lived in the urban area of the city have been followed and evaluated at several time points. The cohort participants were evaluated in 2012–13, and IMT was measured at the posterior wall of the right and left common carotid arteries in longitudinal planes using ultrasound imaging. We obtained valid IMT measurements for 3,188 individuals. Weight-for-age z-score (WAZ) at age 2 years, weight-for-height z-score (WHZ) at age 4, height-for-age z-score (HAZ) at 4 years, WAZ at age 4 and relative conditional weight at 4 years were positively associated with IMT, even after controlling for confounding variables. The beta-coefficient associated with ≥1 s.d. WAZ at age 2 (compared to those with a <–1 s.d.) was 3.62 μm (95% CI 0.86 to 6.38). The beta-coefficient associated with ≥1 s.d. WHZ at 4 (in relation to <–1 s.d) was 3.83 μm (95% CI 0.24 to 7.42). For HAZ at 4, the beta-coefficient for ≥1 s.d. in relation to <–1 s.d. was 4.19 μm (95% CI 1.14 to 7.25). For WAZ at 4, the beta-coefficient associated with ≥1 s.d. in relation to <–1 s.d. was 4.28 μm (95% CI 1.59 to 6.97). The beta-coefficient associated with conditional weight gain at age 2–4 was 1.26 μm (95% CI 0.49 to 2.02).Conclusion
IMT at age 30 was positively associated with WAZ at age 2 years, WHZ at age 4, HAZ at age 4, WAZ at age 4 and conditional weight gain at age 4 years. 相似文献17.
18.
Stephanie Melkonian Maria Argos Megan N. Hall Yu Chen Faruque Parvez Brandon Pierce Hongyuan Cao Briseis Aschebrook-Kilfoy Alauddin Ahmed Tariqul Islam Vesna Slavcovich Mary Gamble Parvez I. Haris Joseph H. Graziano Habibul Ahsan 《PloS one》2013,8(11)
Background
We utilized data from the Health Effects of Arsenic Longitudinal Study (HEALS) in Araihazar, Bangladesh, to evaluate the association of steamed rice consumption with urinary total arsenic concentration and arsenical skin lesions in the overall study cohort (N=18,470) and in a subset with available urinary arsenic metabolite data (N=4,517).Methods
General linear models with standardized beta coefficients were used to estimate associations between steamed rice consumption and urinary total arsenic concentration and urinary arsenic metabolites. Logistic regression models were used to estimate prevalence odds ratios (ORs) and their 95% confidence intervals (CIs) for the associations between rice intake and prevalent skin lesions at baseline. Discrete time hazard models were used to estimate discrete time (HRs) ratios and their 95% CIs for the associations between rice intake and incident skin lesions.Results
Steamed rice consumption was positively associated with creatinine-adjusted urinary total arsenic (β=0.041, 95% CI: 0.032-0.051) and urinary total arsenic with statistical adjustment for creatinine in the model (β=0.043, 95% CI: 0.032-0.053). Additionally, we observed a significant trend in skin lesion prevalence (P-trend=0.007) and a moderate trend in skin lesion incidence (P-trend=0.07) associated with increased intake of steamed rice.Conclusions
This study suggests that rice intake may be a source of arsenic exposure beyond drinking water. 相似文献19.
Lisa-Mari M?rk Stefan Rehnmark Padideh Davoodpour Giuseppe Danilo Norata Lilian Larsson Michael-Robin Witt Johan Malm Paolo Parini 《PloS one》2013,8(12)